WO2015083392A1

WO2015083392A1 - Heat pump device

Info

Publication number: WO2015083392A1
Application number: PCT/JP2014/067592
Authority: WO
Inventors: 藤塚　正史; 和典土野
Original assignee: 三菱電機株式会社
Priority date: 2013-12-04
Filing date: 2014-07-01
Publication date: 2015-06-11
Also published as: JP2017026159A

Abstract

A heat pump device (1) having: a refrigerant circuit (8), in which a refrigerant circulates, and which is formed by connecting, by means of piping, a compressor (2), a first heat exchange unit (4), an expansion device (6), and a second heat exchanger (7); and a control unit (21), which controls the operation of the refrigerant circuit (8). In this heat pump device (1) the first heat exchange unit (4) has multiple heat exchange sub-units connected in series, and an expansion sub-device (43) provided between the multiple heat exchange sub-units. In addition, the control unit (21) has a defrosting control means (22) that controls the expansion sub-device (43) when the heat exchange sub-units are defrosted, so as to generate a difference between the pressure of the refrigerant circulating on the upstream side of the expansion sub-device (43) and the pressure of the refrigerant circulating on the downstream side of the expansion sub-device (43).

Description

Heat pump equipment

The present invention relates to a heat pump device including a refrigerant circuit.

Conventionally, for example, there is a heat pump device that uses outdoor air as a heat source and transfers heat to a heat demand section by a refrigeration cycle. In this heat pump device, means for removing frost generated in a heat exchanger installed outdoors when carrying warm heat to a heat demanding unit has been proposed.

In Patent Document 1, a plurality of first switching valves 25 provided between an outlet side of the outdoor heat exchangers 22 installed in parallel and a suction side of the compressor 21, and the outdoor heat exchangers 22 are arranged. An air conditioner including a second switching valve 26 provided between the outlet side and the discharge side of the compressor 21 is disclosed. This patent document 1 discloses that in the outdoor heat exchanger 22 where defrosting is required, by opening the first switching valve 25 and closing the second switching valve 26, only the outdoor heat exchanger 22 is supplied from the compressor 21. The discharged hot gas refrigerant flows and defrosts. At that time, after being discharged from the compressor 21, it flows in the reverse direction from the outlet side of the outdoor heat exchanger 22 having the defrosting request toward the inlet side, and the refrigerant used for the defrosting and the compressor 21 After being discharged, the refrigerant used for heating through the indoor heat exchanger 41 joins. Then, the merged refrigerant flows through the outdoor heat exchanger 22 where there is no defrost request and absorbs heat. Thereby, this conventional technology tries to defrost the outdoor heat exchanger 22 having a defrosting request while continuing heating in the indoor heat exchanger 41.

In addition, Patent Document 2 discloses a showcase in which a cooling operation is performed by the first evaporator 15c and the second evaporator 16c. In this prior art, by switching a plurality of valves provided in the refrigerant circuit, the high-temperature refrigerant discharged from the compressor 14a circulates in the condenser 14b and dissipates heat, and then does not pass through the expansion valve 23. It distribute | circulates to the 1st evaporator 15c and defrosts the 1st evaporator 15c. And the refrigerant | coolant which flowed out from the 1st evaporator 15c distribute | circulates to the expansion valve 23, absorbs heat with the 2nd evaporator 16c, and cools the inside of a showcase. As described above, Patent Document 2 intends to perform a defrost cooling operation in which the first evaporator 15c is defrosted while the inside of the showcase is cooled by the second evaporator 16c.

JP 2008-157558 A (FIG. 4, pages 7 to 8) JP 2008-133998 A (FIG. 6, page 5)

However, the air conditioner disclosed in Patent Document 1 causes the refrigerant to flow in parallel to the plurality of outdoor heat exchangers 22 in a normal heating operation without defrosting, but in the heating operation with defrosting, the defrosting is performed. The refrigerant flowing through the outdoor heat exchanger 22 having the request is circulated in series to the outdoor heat exchanger 22 having no defrosting request. For this reason, in Patent Document 1, the distribution route of the refrigerant is complicated, and a large number of switching valves are required for switching the complicated distribution route. Therefore, there are problems that it is difficult to reduce the size of the apparatus, the cost is high, and the failure rate is high and the reliability is low. Moreover, when there are many switching valves, the place where a refrigerant | coolant pool generate | occur | produces increases and there also exists a problem which requires a lot of refrigerant | coolants. Further, in Patent Document 1, since defrosting is performed with a high-temperature refrigerant discharged from the compressor 21, the defrosting itself is processed at an early stage, but energy consumption is intense. Moreover, in patent document 2, although the point that energy consumption does not become intense differs, there exists a problem similar to patent document 1 other than that.

The present invention was made against the background of the above problems, and is small, inexpensive, highly reliable, suppresses refrigerant accumulation, has high energy savings, and is comfortable during defrosting or food storage quality. The heat pump apparatus which keeps up is provided.

The heat pump device according to the present invention includes a refrigerant circuit in which a compressor, a first heat exchange unit, an expansion device, and a second heat exchanger are connected by a pipe and through which refrigerant flows, and a control unit that controls the operation of the refrigerant circuit. The first heat exchange unit has a plurality of sub heat exchange units connected in series, and a sub expansion device provided between the plurality of sub heat exchange units, When the control unit defrosts the sub-heat exchange unit, the sub-expansion device causes a difference between the pressure of the refrigerant flowing upstream of the sub-expansion device and the pressure of the refrigerant flowing downstream of the sub-expansion device. It has the control means at the time of defrosting which controls.

According to the present invention, when the defrosting control means defrosts the auxiliary heat exchange unit, the pressure difference between the refrigerant flowing upstream of the auxiliary expansion device and the refrigerant flowing downstream of the auxiliary expansion device is calculated. In order to raise with a subexpansion apparatus, heating, cooling, or cooling is continued by the other subheat exchange part, defrosting at least one subheat exchange part. For this reason, in the user of a heat pump apparatus, comfort and food preservation quality are not impaired at the time of defrosting. Furthermore, these effects can be obtained while saving the effort of switching the operation mode, being small, inexpensive, and highly reliable, suppressing the accumulation of refrigerant, and providing high energy savings.

1 is a schematic diagram showing a heat pump device 1 according to Embodiment 1. FIG. 4 is a schematic diagram showing a heat pump device 1 according to Embodiment 2. FIG. 6 is a schematic diagram showing a heat pump device 200 according to Embodiment 3. FIG. 6 is a schematic diagram showing a first heat exchange unit 4 in Embodiment 4. FIG. FIG. 10 is a schematic diagram showing a first heat exchange unit 4 in a fifth embodiment. FIG. 10 is a schematic diagram showing a first heat exchange unit 4 in a sixth embodiment. FIG. 10 is a schematic diagram showing a second sub heat exchange unit 42 in a sixth embodiment. FIG. 10 is a schematic diagram showing a heat pump device 500 according to a sixth embodiment. FIG. 10 is a schematic diagram showing a heat pump device 600 according to a seventh embodiment.

Hereinafter, an embodiment of a heat pump device according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. Moreover, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a heat pump device 1 according to the first embodiment. The heat pump device 1 will be described with reference to FIG. As shown in FIG. 1, the heat pump device 1 constituting an air conditioner or the like includes a refrigerant circuit 8 and a control unit 21. Among these, the refrigerant circuit 8 is a circuit in which the compressor 2, the first heat exchange unit 4, the expansion device 6, and the second heat exchanger 7 are connected by piping, and the refrigerant circulates. In addition, the refrigerant | coolant to be used is a refrigerant | coolant which carries out a gas-liquid two-phase within the range of the used temperature and pressure like a fluorocarbon type | system | group, a hydrocarbon type | system | group, a carbon dioxide etc., for example.

The refrigerant circuit 8 absorbs heat from, for example, one of the outdoor air 11 and the indoor air 12 and dissipates heat to the other using the condensation and vaporization of the circulating refrigerant. The outdoor air 11 is air as a heat absorption source (during heating operation) or a heat radiation destination (during cooling operation) necessary for cooling and heating the indoor air 12. In the refrigerant circuit 8, heat is efficiently transferred between the outdoor air 11 and the indoor air 12 via the refrigerant with respect to the power required for the compression of the compressor 2. When the indoor air 12 is cooled, the refrigerant that has been reduced in temperature and pressure by the expansion device 6 to be in a gas-liquid two-phase state flows to the second heat exchanger 7 installed in the room. On the other hand, when the indoor air 12 is heated, the refrigerant that has become a high-temperature and high-pressure state in the compressor 2 and is in a gas phase flows through the second heat exchanger 7. As described above, the refrigerant flow direction in the refrigerant circuit 8 is reversed when the indoor air 12 is cooled or heated.

(Compressor 2, pumping switching unit 3)
The compressor 2 pumps the refrigerant in a gas phase to increase the temperature and pressure. On the discharge side of the compressor 2, a pressure feed switching unit 3 is provided. The pressure feed switching unit 3 switches the refrigerant flow direction in the refrigerant circuit 8. This pressure feed switching unit 3 is, for example, a four-way valve, and four connection paths A, B, C, and D are connected to the four-way valve. Among these, the pumping switching unit 3 is connected in the first state in which the connection path A and the connection path B, the connection path C and the connection path D are connected, the connection path A and the connection path C, and the connection path B and the connection path D are connected. The second state can be changed to the second state. For example, the connection path A is connected to the discharge side of the compressor 2, the connection path B is connected to the second heat exchanger 7, the connection path C is connected to the first heat exchange unit 4, and the connection path D is It is connected to the suction side of the compressor 2. By switching the pressure feed switching unit 3, it is changed whether the refrigerant discharged from the compressor 2 flows into the first heat exchange unit 4 or the second heat exchanger 7.

(First heat exchange unit 4)
The first heat exchange unit 4 is used outdoors. For example, the outdoor air 11 blown by a fan (not shown) is used as a heat source to exchange heat between the outdoor air 11 and the refrigerant. . The 1st heat exchange unit 4 is provided with the 1st sub heat exchange part 41 and the 2nd sub heat exchange part 42, and these 1st sub heat exchange parts 41 and the 2nd sub heat exchange part 42 is connected in series. Thereby, the refrigerant does not flow in the parallel direction but always flows in the series direction in the first sub heat exchange unit 41 and the second sub heat exchange unit 42. Note that the number of sub heat exchange units is not limited to two, and a plurality of sub heat exchange units may be installed.

(Sub-expansion device 43)
A sub-expansion device 43 is provided between the first sub-heat exchange unit 41 and the second sub-heat exchange unit 42. The sub-expansion device 43 is a high-pressure liquid-phase refrigerant. Is expanded to lower the temperature and pressure to make a gas-liquid two-phase refrigerant. The sub-expansion device 43 is, for example, an expansion valve that changes the amount of refrigerant flow and the pressure of the refrigerant according to the degree of opening. Since the sub-expansion device 43 is provided between the first sub-heat exchange unit 41 and the second sub-heat exchange unit 42, the refrigerant flowing through the first heat exchange unit 4 is always sub-expansion. Flows into the device 43.

(Sub bypass valve 45)
Further, the refrigerant circuit 8 is provided with a sub-bypass circuit 44 that bypasses the sub-expansion device 43, and the sub-bypass circuit 44 is provided with a sub-bypass valve 45 that adjusts the amount of refrigerant flowing in the sub-bypass circuit 44. It has been. When the sub bypass valve 45 is closed, all the refrigerant flowing through the first heat exchange unit 4 does not flow into the sub bypass circuit 44 but flows into the sub expansion device 43. On the other hand, when the sub bypass valve 45 is opened, the refrigerant flowing through the first heat exchange unit 4 flows into the sub bypass circuit 44 and the sub expansion device 43 separately. At this time, if the sub-expansion device 43 is throttled, the refrigerant flowing into the sub-expansion device 43 decreases, and a large amount of the remaining refrigerant flows into the sub-bypass circuit 44.

(Inflow switching part 5)
In the first heat exchange unit 4, an inflow switching unit 5 is provided on one end side of the first sub heat exchange unit 41, and the inflow switching unit 5 is used for the refrigerant in the first heat exchange unit 4. The distribution direction is switched. The inflow switching unit 5 is a four-way valve, for example, similarly to the pressure-feeding switching unit 3, and the four connection paths A, B, C, and D are connected to the four-way valve. Of these, the inflow switching unit 5 includes the first state in which the connection path A and the connection path B, the connection path C and the connection path D are connected, the connection path A and the connection path C, and the connection path B and the connection path D are connected. The second state can be changed to the second state. For example, the connection path A is connected to the expansion device 6, the connection path B is connected to the first auxiliary heat exchange unit 41, the connection path C is connected to the second auxiliary heat exchange unit 42, and the connection path D is pumped. It is connected to the switching unit 3.

By switching the inflow switching unit 5, when the refrigerant flows into the first heat exchange unit 4, the refrigerant first flows into the first sub heat exchange unit 41 and then flows into the second sub heat exchange unit 42. Or, first, it is changed whether it flows into the 2nd sub heat exchange part 42, and flows into the 1st sub heat exchange part 41 after that. Further, by switching the inflow switching unit 5, the refrigerant flowing out from the first heat exchange unit 4 to the side opposite to the inflow source flows into the suction side of the compressor 2 or flows into the expansion device 6. Is changed.

(First temperature detector 41a and second temperature detector 42a)
The refrigerant circuit 8 includes two first temperature detection units 41a and a second temperature detection unit 42a that detect the temperature of the refrigerant. For example, the first sub heat exchange unit 41 and the sub expansion device 43 are provided. And between the second auxiliary heat exchanging unit 42 and the auxiliary expansion device 43. The first temperature detector 41a and the second temperature detector 42a indirectly detect the temperature of the refrigerant by measuring the temperature of the pipe.

(Expansion device 6)
The expansion device 6 expands a high-pressure liquid-phase refrigerant to lower the temperature and the pressure to obtain a gas-liquid two-phase refrigerant. The expansion device 6 is, for example, an expansion valve that changes the flow rate of the refrigerant and the pressure of the refrigerant at the opening degree.

(Bypass valve 62)
The refrigerant circuit 8 is provided with a bypass circuit 61 that bypasses the expansion device 6, and the bypass circuit 61 is provided with a bypass valve 62 that adjusts the amount of refrigerant flowing in the bypass circuit 61. When the bypass valve 62 is closed, all the refrigerant flowing through the refrigerant circuit 8 does not flow into the bypass circuit 61 but flows into the expansion device 6. On the other hand, when the bypass valve 62 is opened, the refrigerant flowing through the refrigerant circuit 8 flows into the bypass circuit 61 and the expansion device 6 separately. At this time, if the expansion device 6 is throttled, the refrigerant flowing into the expansion device 6 decreases, and the remaining large amount of refrigerant flows into the bypass circuit 61.

(Second heat exchanger 7)
The second heat exchanger 7 is used indoors. For example, the indoor heat 12 blown by a fan (not shown) is used as a heat source, and load heat exchange is performed to exchange heat between the indoor air 12 and the refrigerant. It is a vessel.

(Control unit 21)
The controller 21 controls the operation of the refrigerant circuit 8. The control unit 21 includes a defrosting control unit 22, a threshold determination unit 23, and an end determination unit 24.

(Defrosting control means 22)
When the defrosting control means 22 defrosts the first sub heat exchange unit 41 or the second sub heat exchange unit 42, the refrigerant flowing upstream of the sub expansion device 43 and the downstream of the sub expansion device 43. The sub-expansion device 43 increases the pressure difference with the refrigerant flowing to the side. The defrosting control means 22 can also be configured to open the bypass valve 62 when defrosting the first sub heat exchange unit 41 or the second sub heat exchange unit 42. Further, the defrosting control means 22 may be configured to close the sub bypass valve 45 when the first sub heat exchange unit 41 or the second sub heat exchange unit 42 is defrosted. In addition, the defrosting control means 22 can also control the operation of the expansion device 6.

(Threshold determination means 23, end determination means 24)
The threshold value determination unit 23 determines whether or not the temperature of the refrigerant detected by the first temperature detection unit 41a or the second temperature detection unit 42a is equal to or higher than a predetermined threshold value. This threshold can be set to 0 ° C., for example, but can be changed as appropriate. Then, the end determination unit 24 determines that the temperature of the refrigerant is equal to or higher than the threshold value while the first sub heat exchange unit 41 or the second sub heat exchange unit 42 is defrosted. In this case, it is determined that the defrosting of the first sub heat exchange unit 41 or the second sub heat exchange unit 42 has been completed.

Next, the operation of the heat pump device 1 according to the first embodiment will be described.

(Normal heating operation)
First, the normal heating operation, that is, the operation of absorbing heat by the first heat exchange unit 4 and radiating heat by the second heat exchanger 7 will be described. At this time, the refrigerant is the compressor 2, the pressure switching unit 3, the second heat exchanger 7, the expansion device 6, the inflow switching unit 5, the first heat exchange unit 4, the inflow switching unit 5, the pressure feeding switching unit 3, It distributes in order of the compressor 2. In the first heat exchange unit 4, both the first sub heat exchange unit 41 and the second sub heat exchange unit 42 only absorb heat from the outdoor air 11. The refrigerant may flow into the auxiliary heat exchange unit 41 first, or the refrigerant may flow into the second auxiliary heat exchange unit 42 first. Further, the bypass valve 62 is closed to sufficiently expand the refrigerant by the expansion device 6. Note that the pressure loss in the first heat exchange unit 4 is reduced as much as possible by fully opening the sub expansion device 43 and opening the sub bypass valve 45, or both of them. Note that the opening degree of the sub-expansion device 43 may not be fully opened.

Thus, the high-temperature refrigerant discharged from the compressor 2 exchanges heat with the indoor air 12 in the second heat exchanger 7 to be dissipated to heat the room. At that time, the refrigerant liquefied at a low temperature is expanded by the expansion device 6 to be low-pressure to be gas-liquid two-phase. Then, the refrigerant absorbs heat from the outdoor air 11 in the first heat exchange unit 4 and is vaporized, and is sucked into the compressor 2 to be increased in temperature and pressure again. Thereby, the heat pump device 1 can continuously heat the room.

(Normal cooling operation)
Next, a normal cooling operation, that is, an operation in which heat is radiated by the first heat exchange unit 4 and heat is absorbed by the second heat exchanger 7 will be described. At this time, the refrigerant is the compressor 2, the pressure switching unit 3, the inflow switching unit 5, the first heat exchange unit 4, the inflow switching unit 5, the expansion device 6, the second heat exchanger 7, the pressure feeding switching unit 3, It distributes in order of the compressor 2. Even in this normal cooling operation, in the first heat exchange unit 4, both the first sub heat exchange unit 41 and the second sub heat exchange unit 42 only radiate heat to the outdoor air 11. As in the case of the heating operation, the refrigerant may flow into the first auxiliary heat exchange unit 41 from the inflow switching unit 5 or the refrigerant flows into the second auxiliary heat exchange unit 42 first. Also good. Further, the bypass valve 62 is closed to sufficiently expand the refrigerant by the expansion device 6. Note that the pressure loss in the first heat exchange unit 4 is reduced as much as possible by fully opening the sub expansion device 43 and opening the sub bypass valve 45, or both of them. Note that the opening degree of the sub-expansion device 43 may not be fully opened.

As described above, the high-temperature refrigerant discharged from the compressor 2 is radiated by exchanging heat with the outdoor air 11 in the first heat exchange unit 4. At that time, the refrigerant liquefied at a low temperature is expanded by the expansion device 6 to be low-pressure to be gas-liquid two-phase. The refrigerant absorbs heat from the indoor air 12 in the second heat exchanger 7 to cool the room. Thereafter, the refrigerant that has absorbed heat and is vaporized is sucked into the compressor 2 and is again heated to high temperature and pressure. Thereby, the heat pump device 1 can continuously cool the room.

(Defrosting operation)
As described above, in the heat pump device 1 such as an air conditioner, the normal heating operation and the normal cooling operation are mainly performed. However, if the normal heating operation is continued, in the first heat exchange, the heat contained in the outdoor air 11 is exchanged between the low-temperature refrigerant and the outdoor air 11, so that the moisture contained in the outdoor air 11 is changed to the outer surface of the first heat exchange unit 4. It adheres to and becomes frost. As a result, the heat resistance increases, and the heat exchange efficiency of the first heat exchange unit 4 decreases. When such frost adhesion is left unattended, the air passage is filled with frost, and eventually the air passage is blocked. Thereby, the outdoor air 11 is not circulated, and heat exchange in the first heat exchange unit 4 may be impossible. In order to avoid such a situation, a defrosting operation is required.

(High temperature defrosting operation)
As the defrosting operation, a high temperature defrosting operation (also referred to as hot gas defrosting operation) will be described. In this high-temperature defrosting operation, the refrigerant flow direction is the same as in the normal cooling operation. That is, the high-temperature refrigerant discharged from the compressor 2 flows into the first heat exchange unit 4. Thereby, the frost adhering to the 1st heat exchange unit 4 is melted by the high temperature refrigerant | coolant, and is defrosted. At that time, in the fan provided in the vicinity of the first heat exchange unit 4, heat used for defrosting at the time of the high temperature defrosting operation escapes to the outdoor air 11 having a low temperature at the time of the normal heating operation. Is stopped to suppress Such a high-temperature defrosting operation is one of the most commonly performed defrosting methods in a heat pump device.

However, in this high-temperature defrosting operation, low-temperature refrigerant flows through the second heat exchanger 7, and even if the fan provided in the vicinity of the second heat exchanger 7 is stopped, the removal is performed. Part of the heat source for frosting is covered with indoor air 12. For this reason, defrosting is required during normal heating operation, and when high-temperature defrosting operation is performed, the temperature of the indoor air 12 is lowered and it is difficult to maintain comfort in the room. Therefore, the heat pump device 1 according to the first embodiment ensures comfort by enabling execution of the defrost heating operation and the semi-high temperature defrost operation in addition to the high temperature defrost operation.

(Defrost heating operation)
First, defrosting heating operation, that is, while defrosting one of the first auxiliary heat exchanging part 41 and the second auxiliary heat exchanging part 42, the other heat is absorbed and the second heat exchanger 7 dissipates heat. The driving | operation to perform is demonstrated. As an example, a case where the second sub heat exchange unit 42 absorbs heat while defrosting the first sub heat exchange unit 41 will be described. At this time, the refrigerant is the compressor 2, the pressure switching unit 3, the second heat exchanger 7, the bypass circuit 61 and the expansion device 6, the inflow switching unit 5, the first sub heat exchange unit 41, the sub expansion device 43, The second auxiliary heat exchange unit 42, the inflow switching unit 5, the pumping switching unit 3, and the compressor 2 are distributed in this order.

The defrosting control means 22 in the control unit 21 opens the bypass valve 62, reduces the amount of refrigerant flowing through the expansion device 6, opens the expansion device 6 fully open, and expands the refrigerant in the expansion device 6. Suppress. When the bypass valve 62 is opened, the refrigerant pressure difference before and after the expansion device 6 disappears, so that expansion of the refrigerant is suppressed without fully opening the expansion device 6. However, in order to reduce the pressure loss in the refrigerant circuit 8 as much as possible, the opening degree of the expansion device 6 is fully opened. Then, the defrosting control means 22 in the control unit 21 closes the sub-bypass valve 45 and increases the amount of refrigerant flowing through the sub-expansion device 43 to promote expansion of the refrigerant in the sub-expansion device 43.

Thus, the high-temperature refrigerant discharged from the compressor 2 exchanges heat with the indoor air 12 in the second heat exchanger 7 to be dissipated to heat the room. At that time, the refrigerant having a low temperature by heating the room has at least the temperature of the indoor air 12, that is, a temperature sufficient for defrosting, even if the maximum heat exchange is performed in the second heat exchanger 7. Moreover, since it is not expanded too much in the expansion device 6, it can distribute | circulate to the 1st sub heat exchange part 41, and can defrost this. At this time, for example, the control unit 21 detects that the temperature of the refrigerant that has flowed out of the first auxiliary heat exchange unit 41 (the temperature detected by the first temperature detection unit 41a and is close to the condensation temperature of the refrigerant) is that the frost has melted. The opening degree of the sub-expansion device 43 is adjusted to be slightly higher than the temperature at which the sub-expansion device is set, for example, 1 ° C. Here, when the opening degree of the sub expansion device 43 is increased, the condensation temperature of the refrigerant decreases, and when the opening degree of the sub expansion device 43 is decreased, the condensation temperature of the refrigerant increases. As another method of adjusting the opening degree of the sub-expansion device 43, the control unit 21 determines that the temperature of the refrigerant flowing out from the second heat exchanger 7 (detected by the temperature detection unit 9) You may make it adjust the opening degree of the subexpansion apparatus 43 so that predetermined temperature difference (for example, 4 degreeC) may become higher than temperature.

Furthermore, as another method, the control unit 21 adjusts the opening degree of the sub-expansion device 43 so that the temperature of the refrigerant discharged from the compressor 2 (detected by the temperature detection unit 13) becomes the set discharge temperature. You may do it. Here, when the opening degree of the sub expansion device 43 is increased, the discharge temperature of the refrigerant is lowered, and when the opening degree of the sub expansion device 43 is lowered, the discharge temperature of the refrigerant is raised. In this case, the set discharge temperature is, for example, the temperature of the refrigerant that has flowed out of the first auxiliary heat exchange unit 41 (the temperature detected by the first temperature detection unit 41a and close to the condensation temperature of the refrigerant), and the secondary expansion. The temperature of the refrigerant that expands in the device 43 and flows into the second auxiliary heat exchange unit 42 (the temperature detected by the second temperature detection unit 42a and close to the evaporation temperature of the refrigerant), the frequency of the compressor 2 and It is a value calculated using structural characteristics (such as the volume of the portion to be compressed) and refrigerant characteristics (such as the type of refrigerant, the set degree of superheat or the set degree of cooling). Note that if the lower limit value of the calculated set discharge temperature is set to be at least a predetermined temperature (for example, 5 ° C.) higher than the temperature of the indoor air 12, the refrigerant discharge temperature is excessively lowered and heating is performed. It is possible to avoid such a situation that it becomes impossible.

Furthermore, the method for determining the opening degree of the sub-expansion device 43 is not so-called feedback control in which the opening degree of the sub-expansion device 43 is appropriately changed based on the detected refrigerant discharge temperature or condensation temperature. Also, so-called feedforward control may be used in which the opening degree of the sub-expansion device 43 is uniquely determined by a plurality of patterns determined in advance according to the frequency of the compressor 2 and the temperature of the outdoor air 11. Then, the refrigerant which has been expanded in the auxiliary expansion device 43 and reduced in pressure and gas-liquid two-phased is absorbed by the second auxiliary heat exchanging part 42 from the outdoor air 11 and vaporized, and is sucked into the compressor 2 to be again heated and pressurized again. It becomes.

Thus, the heat pump device 1 absorbs heat at the second sub heat exchange unit 42 and radiates heat at the second heat exchanger 7 while defrosting the first sub heat exchange unit 41, Can be continuously heated. In this defrosting heating operation, although the maximum capacity in the normal heating operation in which heat is absorbed by both the first auxiliary heat exchanging part 41 and the second auxiliary heat exchanging part 42 is not reached, the indoor temperature can be raised to some extent. For example, the need for heating at maximum capacity is low and comfort is not impaired.

(Semi-high temperature defrosting operation)
Next, a semi-high temperature defrosting operation (also referred to as a semi-hot gas defrosting operation), that is, while defrosting one of the first auxiliary heat exchanging part 41 and the second auxiliary heat exchanging part 42, The operation of absorbing heat and absorbing heat in the second heat exchanger 7 will be described. As an example, a case where the second sub heat exchange unit 42 absorbs heat while defrosting the first sub heat exchange unit 41 will be described. At this time, the refrigerant is the compressor 2, the pressure switching unit 3, the inflow switching unit 5, the first sub heat exchange unit 41, the sub expansion device 43, the second sub heat exchange unit 42, the inflow switching unit 5, and the bypass circuit. 61, the expansion device 6, the second heat exchanger 7, the pumping switching unit 3, and the compressor 2 are distributed in this order.

The defrosting control means 22 in the control unit 21 opens the bypass valve 62, reduces the amount of refrigerant flowing through the expansion device 6, opens the expansion device 6 fully open, and expands the refrigerant in the expansion device 6. Suppress. When the bypass valve 62 is opened, the refrigerant pressure difference before and after the expansion device 6 disappears, so that expansion of the refrigerant is suppressed without fully opening the expansion device 6. However, in order to reduce the pressure loss in the refrigerant circuit 8 as much as possible, the opening degree of the expansion device 6 is fully opened. Then, the defrosting control means 22 in the control unit 21 closes the sub-bypass valve 45 and increases the amount of refrigerant flowing through the sub-expansion device 43 to promote expansion of the refrigerant in the sub-expansion device 43. At that time, the controller 21 causes the temperature of the refrigerant flowing out from the first auxiliary heat exchanging unit 41 (the temperature detected by the first temperature detecting unit 41a, which is close to the refrigerant condensing temperature) to melt the frost. The opening degree of the sub expansion device 43 is adjusted so as to be higher than the temperature, for example, 2 ° C. Here, when the opening degree of the sub expansion device 43 is increased, the condensation temperature of the refrigerant decreases, and when the opening degree of the sub expansion device 43 is decreased, the condensation temperature of the refrigerant increases.

Furthermore, as another method, the control unit 21 adjusts the opening degree of the sub-expansion device 43 so that the temperature of the refrigerant discharged from the compressor 2 (detected by the temperature detection unit 13) becomes the set discharge temperature. You may do it. Here, when the opening degree of the sub expansion device 43 is increased, the discharge temperature of the refrigerant is lowered, and when the opening degree of the sub expansion device 43 is lowered, the discharge temperature of the refrigerant is raised. In this case, the set discharge temperature is, for example, the temperature of the refrigerant that has flowed out of the first auxiliary heat exchange unit 41 (the temperature detected by the first temperature detection unit 41a and close to the condensation temperature of the refrigerant), and the secondary expansion. The temperature of the refrigerant that expands in the device 43 and flows into the second auxiliary heat exchange unit 42 (the temperature detected by the second temperature detection unit 42a and close to the evaporation temperature of the refrigerant), the frequency of the compressor 2 and It is a value calculated using structural characteristics (such as the volume of the portion to be compressed) and refrigerant characteristics (such as the type of refrigerant, the set degree of superheat or the set degree of cooling). The method for determining the opening degree of the sub-expansion device 43 is not so-called feedback control in which the opening degree of the sub-expansion device 43 is appropriately changed based on the detected refrigerant discharge temperature or condensing temperature as described above. A so-called feed-forward control may be employed in which the opening degree of the sub-expansion device 43 is uniquely determined by a plurality of patterns determined in advance according to the frequency of the machine 2 and the temperature of the outdoor air 11.

As a result, the high-temperature refrigerant discharged from the compressor 2 flows into the first sub heat exchange unit 41, and the frost adhering to the first sub heat exchange unit 41 is melted by the high-temperature refrigerant and removed. Frosted. Thereafter, the refrigerant that has been expanded in the sub-expansion device 43 and reduced in pressure to be gas-liquid two-phase is vaporized by absorbing heat from the outdoor air 11 in the second sub-heat exchanger 42. Since the vaporized refrigerant is not expanded by the expansion device 6, it remains at a high temperature (although it is at most about the same temperature as the outdoor air 11, which is a heat source), and the outdoor air 11 is cooler than the indoor air 12. It is not a temperature at which the indoor air 12 can be heated during normal heating), and flows into the second heat exchanger 7. At that time, since the refrigerant flows into the second heat exchanger 7 while maintaining a high temperature as compared with the high temperature defrosting operation, excessive heat absorption in the second heat exchanger 7 is suppressed. And the refrigerant | coolant which flowed out from the 2nd heat exchanger 7 is suck | inhaled by the compressor 2, and is high-temperature-high pressure again.

Thus, in the semi-high temperature defrosting operation, unlike the defrosting heating operation, heating is not continued while defrosting, but most of the heat source necessary for defrosting is the second auxiliary heat exchange unit 42. It is covered by outdoor air 11. On the other hand, in the high temperature defrosting operation, the second auxiliary heat exchanging unit 42 is also defrosted, so the heat source necessary for defrosting is the indoor air 12 in the second heat exchanger 7. Therefore, in the semi-high temperature defrosting operation, the heat absorption from the indoor air 12 in the second heat exchanger 7 is suppressed more than in the high temperature defrosting operation. Thus, even if defrosting is necessary during normal heating operation, if the semi-high temperature defrosting operation is performed, the temperature of the indoor air 12 is suppressed from excessively decreasing, and thus comfortable. Does not impair sex.

In addition, although the example which defrosts the 1st sub heat exchange part 41 in the defrost heating operation or the semi-high temperature defrost operation was demonstrated, by switching the inflow switching part 5, the 2nd sub heat exchange part 42 is changed. It is also possible to defrost. Further, both the defrosting heating operation and the semi-high temperature defrosting operation may be appropriately changed by the control unit 21. For example, when the room is not sufficiently warm and the room temperature is low, the defrost heating operation is performed and the heating is continued. In addition, when the room is sufficiently warm and the room temperature is high, a semi-high temperature defrosting operation is performed to increase the defrosting capacity and to defrost in a shorter time so that the normal heating operation can be quickly restored. . On the contrary, when the room is not sufficiently warm, the semi-high temperature defrosting operation may be performed, and when the room is sufficiently warm, the defrosting heating operation may be performed. In this way, by properly using the defrosting heating operation and the semi-high temperature defrosting operation, it is possible to appropriately select whether to give priority to indoor comfort or to defrost efficiency.

Further, in these defrosting heating operation or semi-high temperature defrosting operation, the control unit 21 determines the end of the defrosting. Specifically, the threshold determination unit 23 determines whether or not the temperature of the refrigerant detected by the first temperature detection unit 41a or the second temperature detection unit 42a is equal to or higher than a predetermined threshold, When the threshold determination unit 23 determines that the temperature of the refrigerant is equal to or higher than the threshold while the end determination unit 24 defrosts the first sub heat exchange unit 41 or the second sub heat exchange unit 42. It is determined that the defrosting of the auxiliary heat exchange unit has been completed. This determination uses an action in which the temperature of the refrigerant starts to rise rapidly because the heat absorption source disappears when the defrosting in the auxiliary heat exchange unit is completed. When the opening degree of the sub-expansion device 43 is controlled according to the condensation temperature, the temperature rise of the refrigerant as described above is suppressed by controlling the opening degree of the sub-expansion device 43. For this reason, you may make it determine with the defrosting having been complete | finished based on the opening degree of the subexpansion apparatus 43 becoming large rapidly.

In addition, when defrosting the 1st sub heat exchange part 41, what is necessary is just to determine with the temperature of the refrigerant | coolant (or raise of the opening degree of the sub expansion apparatus 43) detected by the 1st temperature detection part 41a, and 2nd In the case of defrosting the auxiliary heat exchanging section 42, the temperature of the refrigerant detected by the second temperature detecting section 42a (or the increase in the degree of opening of the auxiliary expansion device 43) may be determined. In addition, the defrosting end determination in the high temperature defrosting operation is performed using the temperature detection unit 10 provided between the first heat exchange unit 4 and the expansion device 6, and the refrigerant flowing out from the first heat exchange unit 4. What is necessary is just to judge by whether temperature is more than a predetermined threshold value. The predetermined threshold value is set to a temperature (for example, 3 ° C.) slightly higher than 0 ° C. as a temperature at which frost melts. This is because the temperature of the refrigerant does not become higher than the temperature at which the frost melts due to the heat of melting of the frost unless the defrosting of the auxiliary heat exchange unit is completed, and the temperature is slightly higher. This is because it takes into account the increase in the thermal resistance between the refrigerant and the frost and the change in the melting temperature of the frost due to the atmospheric pressure of the outdoor air 11.

As described above, in the heat pump device 1 according to the first embodiment, the first heat exchange unit 4 installed outdoors has the first sub heat exchange unit 41, the second sub heat exchange unit 42, and the sub heat exchange unit 42. The expansion device 43 is configured. When the defrosting control means 22 defrosts the first sub heat exchange section 41 or the second sub heat exchange section 42, the pressure difference of the refrigerant flowing through the first heat exchange unit 4 is sub-expanded. Increase with device 43. Thereby, in order to defrost one of the 1st sub heat exchange part 41 and the 2nd sub heat exchange part 42, the heat pump apparatus 1 thermally radiates, and it absorbs heat from the other simultaneously.

And even if any one of the 1st sub heat exchange part 41 and the 2nd sub heat exchange part 42 is defrosted, the 2nd heat exchanger 7 installed indoors by absorbing heat from the other. Thus, warm heat can be supplied to the indoor air 12 (defrost heating operation). Moreover, even if any one of the 1st sub heat exchange part 41 and the 2nd sub heat exchange part 42 is defrosted, the quantity absorbed by the 2nd heat exchanger 7 is absorbed by absorbing heat from the other. It can be reduced (semi-high temperature defrosting operation). Thereby, in defrost heating operation, comfort is improved dramatically, and comfort is not impaired in semi-high temperature defrost operation.

As described above, in the defrost heating operation, the defrosting can be performed while the heat is supplied to the room which is the heat demand section, so that the user's discomfort is suppressed and the comfort is improved. In the defrosting heating operation, the refrigerant discharged from the compressor 2 is supplied to the second heat exchanger 7 (load heat exchanger) before the first heat exchange unit 4. Of the first heat exchange unit 4, the first sub heat exchange unit 41 or the second sub heat exchange unit 42 is defrosted using the residual heat of the refrigerant radiated by the second heat exchanger 7. . For this reason, energy efficiency is high. In the high-temperature defrosting operation and the semi-high temperature defrosting operation, the high-temperature refrigerant discharged from the compressor 2 is supplied to the first heat exchange unit 4 before the second heat exchanger 7. Although energy efficiency is not so high, it is possible to defrost at high speed.

In addition, since only the sub-expansion device 43 is added, the defrosting heating operation and the semi-high temperature defrosting operation are realized. Therefore, the distribution route is simple, and the size and cost of the device increase with the increase in the number of devices. The rise can be suppressed. Further, the refrigerant flow path is the same in the normal heating operation and the defrosting heating operation, and is the same in the normal cooling operation and the semi-high temperature defrosting operation. For this reason, an unnecessary valve required for switching the operation mode can be omitted, and the number of portions where the refrigerant pool is generated can be reduced. Therefore, the refrigerant pool does not occur before and after the defrosting process, the process for eliminating the refrigerant pool is unnecessary, and the operation of the heat pump device 1 is simple. Thereby, it is allowed to lower the pressure resistance performance of the pipe, and an increase in the amount of the refrigerant can be suppressed, so that an increase in cost can be suppressed.

Further, since the pressure feed switching unit 3 is provided, the flow direction of the refrigerant can be changed by the pressure feed switching unit 3. For this reason, both normal heating operation for supplying warm air to the indoor air 12 and normal cooling operation for supplying cold heat to the indoor air 12 are possible. Further, the refrigerant discharged from the compressor 2 is supplied to the second heat exchanger 7 (load heat exchanger) prior to the first heat exchange unit 4, and the second heat exchanger 7 Defrosting heating operation for defrosting the first auxiliary heat exchanging part 41 or the second auxiliary heat exchanging part 42 in the first heat exchanging unit 4 using the residual heat of the radiated refrigerant, and compression The high-temperature refrigerant discharged from the machine 2 is supplied to the first heat exchange unit 4 before the second heat exchanger 7, and the first sub heat exchange in the first heat exchange unit 4 is performed. The high temperature defrosting operation and the semi-high temperature defrosting operation in which the part 41 or the second auxiliary heat exchange unit 42 is directly defrosted with a high temperature refrigerant can be used properly.

Furthermore, since the inflow switching unit 5 is provided, the inflow switching unit 5 can change the flow direction of the refrigerant in the first heat exchange unit 4. Further, the defrosting control means 22 increases the pressure difference of the sub expansion device 43 while switching the refrigerant flow direction in the inflow switching unit 5, whereby the first sub heat exchange unit 41 and the second sub heat. Of the exchange part 42, heat can be removed and defrosted to the auxiliary heat exchange part through which the refrigerant flows first, and then absorbed by the auxiliary heat exchange part through which the refrigerant flows. Furthermore, by adopting both the inflow switching unit 5 and the pressure feeding switching unit 3, the defrosting heating operation and the semi-high temperature defrosting operation are performed by the first sub heat exchange unit 41 and the second sub heat exchange. This can be done in part 42.

Further, since the bypass circuit 61 and the bypass valve 62 are provided, the operation of closing the bypass valve 62 and increasing the refrigerant pressure difference before and after the expansion device 6, that is, normal heating operation, normal cooling operation, and An operation in which the high-temperature defrosting operation is possible and the bypass valve 62 is opened to reduce the refrigerant pressure difference before and after the expansion device 6 and increase the refrigerant pressure difference before and after the auxiliary expansion device 43, that is, Defrosting heating operation and semi-high temperature defrosting operation are possible. For this reason, the energy efficiency at the time of defrosting improves.

Further, since the auxiliary bypass circuit 44 and the auxiliary bypass valve 45 are provided, the operation of closing the auxiliary bypass valve 45 and increasing the refrigerant pressure difference before and after the auxiliary expansion device 43, that is, the defrosting heating operation. In addition, the semi-high temperature defrosting operation is possible, and by opening the auxiliary bypass valve 45 and bypassing the auxiliary expansion device 43, the pressure difference of the refrigerant before and after the auxiliary expansion device 43 is reduced, and the first auxiliary defrosting operation is performed. An operation that absorbs or dissipates heat from both the heat exchange unit 41 and the second auxiliary heat exchange unit 42, that is, a normal heating operation, a normal cooling operation, and a high-temperature defrosting operation are possible. Thereby, the increase in the pressure loss in the 1st heat exchange unit 4 can be suppressed, and the fall of efficiency can be suppressed.

Furthermore, since the expansion valve which adjusts the flow volume of a refrigerant | coolant and the pressure difference of a refrigerant | coolant with an opening degree is employ | adopted for the subexpansion apparatus 43, the pressure difference of the refrigerant | coolant before and behind the subexpansion apparatus 43 can be finely adjusted. . For this reason, the precision of the change of the operating condition at the time of defrosting, temperature adjustment, etc. improves.

Furthermore, since the first temperature detection unit 41a or the second temperature detection unit 42a is provided, the determination accuracy of the completion of the defrosting in the defrosting heating operation and the semi-high temperature defrosting operation is extremely high. For this reason, useless energy consumption required for defrosting can be suppressed. Moreover, the defrosting time can be suppressed, and the effect of improving comfort or reducing discomfort is further enhanced.

(Modification)
Next, a heat pump device 1 according to a modification of the first embodiment will be described. When the normal cooling operation, the high-temperature defrosting operation, and the semi-high temperature defrosting operation are unnecessary, the heat pump device 1 can perform the normal heating operation and the defrosting heating operation even if the pumping switching unit 3 is omitted. Further, when the normal heating operation and the defrosting heating operation are unnecessary, the normal cooling operation, the high temperature defrosting operation, and the semi-high temperature defrosting operation are possible even if the pumping switching unit 3 is omitted. Thus, if the kind of driving | operation is selected according to a use, the pumping switching part 3 can be omitted.

Further, when only one of the first sub heat exchange unit 41 and the second sub heat exchange unit 42 needs to be defrosted, the inflow switching unit 5 can be omitted. For example, when frost is likely to be generated in one of the first sub heat exchange unit 41 and the second sub heat exchange unit 42 (for example, frost formation on the sub heat exchange unit on the upstream side with respect to the flow of the outdoor air 11). In such a case, one of them can be defrosted at a high speed by a semi-high temperature defrosting operation, and the other can be defrosted while being heated by a defrosting heating operation. Alternatively, either the first sub heat exchange unit 41 or the second sub heat exchange unit 42 is defrosted while being heated by the defrost heating operation, and both are simultaneously defrosted at a high speed by the high temperature defrost operation. You may do it. Thereby, even if it omits the inflow switching part 5, when it is at least a semi-high temperature defrost operation or a defrost heating operation, the fall of comfort can be suppressed.

Further, even if the opening degree of the expansion device 6 is fully opened, the bypass circuit 61 and the bypass valve 62 can be omitted as long as the pressure loss is in an allowable range. This contributes to cost reduction. Similarly to the expansion device 6, even if the opening degree of the sub expansion device 43 is fully opened, the sub bypass circuit 44 and the sub bypass valve 45 can be omitted as long as the pressure loss is within an allowable range.

Furthermore, the sub-expansion device 43 may be configured by a capillary tube instead of the expansion valve that adjusts the refrigerant flow rate. This capillary tube does not change the opening degree like an expansion valve, and the pressure difference before and after passage is fixed in accordance with the circulation amount of the refrigerant. Thereby, in the case of defrosting heating operation, etc., since the operating conditions such as the frequency of the compressor 2 are fixed, the degree of freedom of the operating conditions and the degree of freedom of adjustment are slightly lower than those of the expansion valve. Although the effect is reduced, the same effect as in the first embodiment can be obtained while reducing the cost and size. In addition, since the number of movable parts called the sub-expansion device 43 is reduced, the risk of failure is reduced and the reliability is improved.

Furthermore, in the first embodiment, the configuration in which the indoor air 12 is heated or cooled by the second heat exchanger 7 in the heat demand section has been described. However, the present invention is not limited to this. It is good also as a structure to cool. In this case, the liquid heated or cooled by the second heat exchanger 7 may be used to indirectly heat or cool the room with a fan coil, radiator, floor heating, or the like disposed in the room. Good. Thus, instead of heating or cooling the indoor air 12, the heat demand unit may generate hot water, hot water for heating, cold water for cooling, or the like.

In the first embodiment, the bypass valve 62 and the sub bypass valve 45 have been described as on-off valves that adjust whether the refrigerant flows or stops in the bypass circuit 61 and the sub bypass circuit 44. It is preferable to use a valve that gradually changes (for example, 2 minutes are required for opening and closing) including an intermediate opening between the closed state and the fully opened state. In this case, when various operation modes (normal heating operation, defrost heating operation, high temperature defrost operation, semi-high temperature defrost operation, etc.) are switched, the temperature, pressure or amount of the refrigerant in each part of the refrigerant circuit 8 is rapidly changed. Smooth switching is possible while suppressing various fluctuations.

Moreover, in the said Embodiment 1, the completion | finish judgment of the defrost in a defrost heating operation, a semi-high temperature defrost operation, or a high temperature defrost operation is made into the 1st temperature detection part 41a, the 2nd temperature detection part 42a, or temperature detection. Although the absolute value comparison of the temperature detected in the unit 10 is performed, the relative value comparison by the temperature change at a predetermined time interval, or both the absolute value comparison and the relative value comparison may be performed. In this case, the same effect as that of the first embodiment is obtained.

Furthermore, in Embodiment 1, it is preferable that the heat pump apparatus 1 is provided with the suppression means which suppresses heat exchange with the exterior of the sub bypass valve 45, and air. Thereby, during the normal heating operation, even if the sub bypass valve 45 is fully opened and the low-temperature refrigerant passes, the movable part outside the sub bypass valve 45 is frosted and the operation is inhibited. be able to. The suppression means can be realized, for example, by laying a heat insulating material on the outside of the sub bypass valve 45, or by forming a two-layer structure outside the movable part of the sub bypass valve 45 and enclosing a dry gas between the layers. In addition, the suppression means is arranged at a location away from the auxiliary heat exchange part so that it does not come in contact with moisture, or a shielding part is provided between the auxiliary heat exchange part so that the air containing moisture is difficult to hit. It can be realized by doing. Thereby, the frost formation to the sub bypass valve 45 can be suppressed, and the malfunction of the operation | movement by icing can be suppressed.

Moreover, the heat pump device 1 may include a heating unit such as a heater in the sub bypass valve 45 instead of the suppression means. When it is determined by the control unit 21 that it is necessary to operate the sub bypass valve 45 after a normal heating operation or the like, the sub bypass valve 45 is heated by the heating unit and defrosted, whereby ice accretion is achieved. Thus, the sub bypass valve 45 can be operated reliably. Furthermore, the heat pump device 1 may include both the suppression unit and the heating unit. In this case, heat radiation from the heating unit to the outside can be suppressed, and the outside of the sub bypass valve 45 can be efficiently defrosted.

Embodiment 2. FIG.
Next, the heat pump apparatus 100 according to the second embodiment will be described. FIG. 2 is a schematic diagram showing a heat pump device 100 according to the second embodiment. The second embodiment is different from the first embodiment in that a plurality of flow paths through which the refrigerant branches and flows are formed in the first sub heat exchange section 41 and the second sub heat exchange section 42. Is different. In the second embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

In the second embodiment, as shown in FIG. 2, a first circulation path 4 a and a second circulation path 4 b are formed in the first auxiliary heat exchanging part 41 so that the refrigerant always branches and flows in parallel. ing. The first distribution path 4a and the second distribution path 4b are also formed in the second auxiliary heat exchange unit 42 as they are. The first flow path 4a branches between the first sub heat exchange unit 41 and the second sub heat exchange unit 42, one is connected to one end of the sub expansion device 43, and the other is the first It is connected to one end of the sub bypass circuit 44a. The first flow path 4a joins again at the other end of the sub-expansion device 43 and the other end of the first sub-bypass circuit 44a. The first sub bypass circuit 44a is provided with a first sub bypass valve 45a. The first sub bypass valve 45a controls whether or not the refrigerant flows through the first sub bypass circuit 44a.

The second flow path 4b also branches between the first sub heat exchange unit 41 and the second sub heat exchange unit 42, one of which is connected to one end of the sub expansion device 43, and the other is the second sub heat exchange unit 42. 2 is connected to one end of the secondary bypass circuit 44b. Then, the second flow path 4b joins again at the other end of the sub expansion device 43 and the other end of the second sub bypass circuit 44b. The second sub bypass circuit 44b is provided with a second sub bypass valve 45b. The second sub bypass valve 45b controls whether or not the refrigerant flows through the second sub bypass circuit 44b.

As described above, the secondary expansion device 43 is installed at a portion where the first distribution path 4a and the second distribution path 4b merge. The first temperature detection unit 41a and the second temperature detection unit 42a are provided at both ends of the sub-expansion device 43 installed at the portion where the first flow path 4a and the second flow path 4b merge. It has been.

The heat pump device 100 according to the second embodiment is different from the first embodiment in that a plurality of distribution paths are formed, but a normal heating operation, a normal cooling operation, a defrost heating operation, and a semi-high temperature defrost operation. The operation of the high temperature defrosting operation is the same as that of the first embodiment. Note that the first sub-bypass valve 45a and the second sub-bypass valve 45b in the second embodiment are simultaneously opened and closed at the same timing when the sub-bypass valve 45 in the first embodiment is opened and closed. The configuration adopted in the modification of the first embodiment can also be adopted in the second embodiment.

As described above, in the second embodiment, the first flow path 4a and the second flow path through which the refrigerant branches and flows to the first sub heat exchange unit 41 and the second sub heat exchange unit 42. Since 4b is formed, the pressure loss in the 1st sub heat exchange part 41 and the 2nd sub heat exchange part 42 is reduced more. For this reason, in addition to the effect obtained in the first embodiment, the efficiency of the refrigeration cycle in the refrigerant circuit 8 can be increased.

Further, since the first secondary bypass circuit 44a and the second secondary bypass circuit 44b are connected to the first circulation path 4a and the second circulation path 4b, respectively, bypass for bypassing the secondary expansion device 43 The function is improved and the pressure difference of the refrigerant is reduced. Further, even if the pressure difference or temperature of the refrigerant in the first circulation path 4a and the second circulation path 4b is somewhat unbalanced, the first circulation path 4a and the second circulation path are formed at both ends of the sub-expansion device 43. Since the two distribution channels 4b once join, this imbalance is corrected naturally. At that time, the first distribution path 4a and the second distribution path 4b are merged after branching to the first sub-bypass circuit 44a and the second sub-bypass circuit 44b, respectively. There is no increase in pressure loss, or a large increase.

In the second embodiment, the first sub bypass valve 45a and the second sub bypass valve 45b are provided separately for the first sub bypass circuit 44a and the second sub bypass circuit 44b, respectively. Although it is a body valve, it is opened and closed simultaneously at the same timing, and even if the valve body is formed integrally or a single motor that supplies the driving power required for opening and closing is combined Good. In this case, it becomes easier to obtain the effect of downsizing or cost reduction.

Further, a plurality of first sub-bypass circuits 44a and first sub-bypass valves 45a may be provided in the first distribution path 4a. A plurality of second sub-bypass circuits 44b and second sub-bypass valves 45b may be provided in the second flow path 4b. In the second embodiment, the same number of flow paths (the first flow path 4a and the second flow path) are used in the first sub heat exchange unit 41 and the second sub heat exchange unit 42 before and after the sub expansion device 43. However, a different number of distribution channels may be used. In this case, on the side having a small number of distribution paths before and after the secondary expansion device 43, a plurality of secondary bypass circuits are branched from at least one distribution path.

Embodiment 3 FIG.
Next, the heat pump device 200 according to the third embodiment will be described. FIG. 3 is a schematic diagram showing a heat pump device 200 according to the third embodiment. The third embodiment is different from the first embodiment in that the heat exchange unit 4 includes a plurality of, for example, first heat exchange units 4-1 and 4-2. In the third embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

As shown in FIG. 3, the third embodiment includes two first heat exchange units 4-1 and 4-2, and the refrigerant flows from the inflow switching unit 5 to the refrigerant forward piping and the return passage. In the middle of each pipe, the first heat exchange units 4-1 and 4-2 are branched in parallel, and then merged. The first heat exchange unit 4-1 includes a first sub heat exchange unit 41-1, a second sub heat exchange unit 42-1, a first temperature detection unit 41a-1, and a second temperature detection unit 42a. -1, a secondary expansion device 43-1, a secondary bypass circuit 44-1, and a secondary bypass valve 45-1. Further, the second heat exchange unit 4-2 includes a first sub heat exchange unit 41-2, a second sub heat exchange unit 42-2, a first temperature detection unit 41a-2, and a second temperature detection. A portion 42a-2, a sub expansion device 43-2, a sub bypass circuit 44-2, and a sub bypass valve 45-2 are provided. Thus, the first heat exchange unit 4-1 and the second heat exchange unit 4-2 have the same configuration.

In the third embodiment, regardless of the operation mode, the refrigerant flowing from the inflow switching unit 5 always branches in parallel to the first heat exchange units 4-1, 4-2 and flows into the first heat exchange units 4-1, 4-2. The refrigerant discharged from the heat exchange units 4-1 and 4-2 joins and returns to the inflow switching unit 5. Therefore, as in the first embodiment, in each of the first heat exchange units 4-1 and 4-2, the refrigerant flow is always the same as in the first embodiment regardless of the operating state. In series.

In the defrosting heating operation or the semi-high temperature defrosting operation, the first auxiliary heat exchange units 41-1 and 41-2 are defrosted at the same time, or the second auxiliary heat exchange units 42-1 and 42- The operation of either defrosting 2 at the same time is performed. At that time, the sub bypass valves 45-1 and 45-2 are simultaneously closed, and the control unit 21 performs the same method as in the first embodiment in accordance with the discharge temperature (temperature detected by the temperature detection unit 13). The sub-expansion devices 43-1 and 43-2 are set to the same opening degree. As another example of the control method, when the first sub heat exchange units 41-1 and 41-2 are defrosted simultaneously, the opening degree of the sub expansion device 43-1 is determined by the first temperature detection unit. 41a-1 is controlled according to the temperature (close to the condensing temperature, more precisely, the temperature obtained by subtracting the subcooling temperature from the condensing temperature), and the opening degree of the sub expansion device 43-2 is determined by the first temperature detecting unit. The temperature may be controlled according to the temperature detected at 41a-2 (close to the condensation temperature, more precisely, the temperature obtained by subtracting the subcool temperature from the condensation temperature).

Further, the opening degree of the sub expansion devices 43-1 and 43-2 depends on the temperature of the first temperature detection units 41a-1 and 41a-2 (or the second temperature detection units 42a-1 and 42a-2). The opening ratio of the sub-expansion devices 43-1 and 43-2 is maintained at a controlled value according to the discharge temperature (the temperature detected by the temperature detector 13). The discharge temperature and the temperature close to the condensation temperature may be controlled simultaneously by increasing / decreasing itself. Then, when the detection values of the first temperature detection units 41a-1 and 41a-2 are both higher than a predetermined value, it is determined that the defrosting is finished.

As described above, the third embodiment has a configuration in which a plurality of first heat exchange units 4-1 and 4-2 are arranged in parallel, and performs the same operation as in the first embodiment. The pressure loss of the refrigerant circuit 8 on the first heat exchange units 4-1 and 4-2 side is further suppressed.

Embodiment 4 FIG.
Next, the 1st heat exchange unit 4 in this Embodiment 4 is demonstrated. FIG. 4 is a schematic diagram showing the first heat exchange unit 4 in the fourth embodiment. In the fourth embodiment, the heat pump device 300 includes the blower fan 46, and the blower fan 46 is provided individually for each of the plurality of sub heat exchange units in the first heat exchange unit 4. This is different from the first embodiment. In the fourth embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

In the fourth embodiment, as shown in FIG. 4, in the heat pump device 300, the first sub heat exchange unit 41 and the second sub heat exchange unit 42 in the first heat exchange unit 4 are individually connected to the first heat exchange unit 41. A first blower fan 46a and a second blower fan 46b are provided. Further, a partition plate 47 is provided between the first sub heat exchange unit 41 and the second sub heat exchange unit 42, and this partition plate 47 is blown by the first blower fan 46a. The outdoor air 11a and the outdoor air 11b blown by the second blower fan 46b are separated. Thereby, when the 1st ventilation fan 46a rotates, the outdoor air 11a is ventilated to the 1st auxiliary heat exchange part 41, and when the 2nd ventilation fan 46b rotates, the outdoor air 11b becomes 2nd auxiliary heat. Air is sent to the exchange unit 42.

Next, the operation of the defrosting heating operation or the semi-high temperature defrosting operation in the fourth embodiment will be described. When defrosting one of the first sub heat exchange unit 41 and the second sub heat exchange unit 42 (defrost heating operation or semi-high temperature defrost operation), the control unit 21 performs defrosting. The blower fan on the side of the heat exchange unit is stopped, and the blower fan on the side of the auxiliary heat exchange unit that is not defrosted is operated to continue the heat absorption operation. For example, when the first sub heat exchange unit 41 is defrosted and the second sub heat exchange unit 42 continues the heat absorption operation, the rotation of the first blower fan 46a is stopped and the outdoor air 11a is changed to the first sub heat exchange unit 42. While not being supplied to the heat exchanging part 41, the second blower fan 46 b is rotated, and the outdoor air 11 b is supplied to the second auxiliary heat exchanging part 42. Thereby, since it becomes difficult to radiate heat to the outdoor air 11a in the first sub heat exchange part 41, it is possible to efficiently defrost, and the second sub heat exchange part 42 efficiently absorbs heat from the outdoor air 11b. be able to.

Further, in the high temperature defrosting operation, the control unit 21 stops the rotation of both the first blower fan 46a and the second blower fan 46b, and efficiently suppresses heat radiation from the refrigerant to the outdoor air 11. Defrosted. In the normal heating operation or the normal cooling operation, the control unit 21 rotates both the first blower fan 46a and the second blower fan 46b, and the first heat exchange unit 4 performs the normal heating operation. Heat can be absorbed from the outdoor air 11 efficiently, and heat can be efficiently radiated to the outdoor air 11 in the normal cooling operation.

In the fourth embodiment, the partition plate 47 is provided, but the partition plate 47 may be omitted. Further, when the fourth embodiment and the third embodiment are combined, one blower fan corresponding to the first sub heat exchange units 41-1 and 41-2 is provided, and the second sub heat exchange unit 42 is provided. -1 and 42-2 may be provided with another blower fan.

Embodiment 5 FIG.
Next, the 1st heat exchange unit 4 in this Embodiment 5 is demonstrated. FIG. 5 is a schematic diagram showing the first heat exchange unit 4 in the fifth embodiment. In the fifth embodiment, the heat pump device 400 includes the blower fan 46, and the blower fan 46 is different from the first embodiment in that the air blowing direction can be switched in both directions. In the fifth embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

In the fifth embodiment, as shown in FIG. 5, in the heat pump device 400, the blowing fan 46 switches the direction of blowing the outdoor air 11 in both directions by changing the rotation direction. Here, a direction in which the air is blown from the auxiliary heat exchange unit to the blower fan 46 is a forward direction 11c, and a direction in which the air is blown from the blower fan 46 to the auxiliary heat exchange unit is a reverse direction 11d. Further, the first sub heat exchange part 41 and the second sub heat exchange part 42 are arranged in series with respect to the air blowing direction of the air blown by the blower fan 46.

Next, the operation of the heat pump apparatus 400 according to the fifth embodiment will be described. In the fifth embodiment, when one of the first sub heat exchange unit 41 and the second sub heat exchange unit 42 is to be defrosted (defrost heating operation, semi-high temperature defrost operation), the control unit The defrosting control means 22 in 21 changes the air blowing direction in the blower fan 46 so that the defrosting side auxiliary heat exchanging part is located upstream of the air blowing direction in the blower fan 46. Switch.

For example, when defrosting the first auxiliary heat exchanging part 41 and continuing the heat absorption operation of the second auxiliary heat exchanging part 42, the defrosting control means 22 determines the blowing direction of the outdoor air 11 by the blower fan 46, Switch to the forward direction 11c. In addition, when the second sub heat exchange unit 42 is defrosted and the first sub heat exchange unit 41 continues to perform an endothermic operation, the defrosting control unit 22 determines the blowing direction of the outdoor air 11 by the blower fan 46. Switch to the reverse direction 11d. At this time, the rotational speed of the blower fan 46 is set lower than that in the normal heating operation or the normal cooling operation so that the heat released from the refrigerant during the defrosting is not excessively taken away by the outdoor air 11. It is preferable to make it. Further, during the high temperature defrosting operation, the blower fan 46 is stopped in order to efficiently defrost.

Thereby, the heat released from the refrigerant in the upstream side secondary heat exchange unit for defrosting is recovered as a heat absorption source in the downstream side secondary heat exchange unit that continues the endothermic operation. For this reason, it is possible to achieve efficient defrosting and heat absorption only by providing one blower fan 46, and to reduce the number of parts, and to manufacture a heat pump device 400 with low cost, compactness, low failure risk, and high reliability. Can do.

When the fifth embodiment and the third embodiment are combined, the first auxiliary heat exchanging units 41-1 and 41-2 are arranged in parallel upstream or downstream with respect to the blowing direction in the blower fan 46. The second auxiliary heat exchange units 42-1 and 42-2 are arranged in parallel on the downstream side or the upstream side with respect to the blowing direction in the blower fan 46, and the first auxiliary heat exchange units 41-1 and 41- are arranged. 2 and the second auxiliary heat exchanging units 42-1 and 42-2 may be arranged in series with respect to the blowing direction of the blowing fan 46.

Embodiment 6 FIG.
Next, the 1st heat exchange unit 4 in this Embodiment 6 is demonstrated. FIG. 6 is a schematic diagram showing the first heat exchange unit 4 in the sixth embodiment. The sixth embodiment is different from the first embodiment in that the heat pump device 500 includes a blower fan 46 and a heating unit 48. In the sixth embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

In the sixth embodiment, as shown in FIG. 6, the first auxiliary heat exchanging part 41 and the second auxiliary heat exchanging part 42 are arranged in series with respect to the blowing direction of the air blown by the blower fan 46. The first auxiliary heat exchanging part 41 is arranged on the upstream side with respect to the blowing direction of the air blown by the blower fan 46. Further, between the first sub heat exchange section 41 and the second sub heat exchange section 42, along the second sub heat exchange section 42 on the second sub heat exchange section 42 side, For example, a heating means 48 which is an electric heater is provided.

FIG. 7 is a schematic diagram showing the second sub heat exchange unit 42 in the sixth embodiment. As shown in FIG. 7, the second auxiliary heat exchanging unit 42 has a plurality of plate fins 49 stacked, and two refrigerant tubes 50 penetrate these plate fins 49 in the stacking direction. Yes. The refrigerant pipe 50 is a part of the first circulation path 4a, the second circulation path 4b in the second embodiment, or the refrigerant circuit 8 in other embodiments. The heating means 48 is disposed in parallel with the refrigerant pipe 50 along the outer edge of the second sub heat exchange part 42. The heating means 48 may not be arranged in parallel with the refrigerant pipe 50, and is not attached to the outer edge of the second auxiliary heat exchanging section 42, but is attached to a part of the refrigerant pipe 50 or the plate fin 49. It may be worn or built in.

FIG. 8 is a schematic diagram showing a heat pump device 500 according to the sixth embodiment. As shown in FIG. 8, the refrigerant circuit 8 a of the heat pump device 500 does not include the pressure feed switching unit 3 and the inflow switching unit 5. Moreover, the expansion device 6 is provided with a plurality of

capillary tubes

63 and 64 and shut-off valves 63a and 63b that cause a fixed pressure loss instead of the expansion valve as in the above-described embodiment. The shut-off valves 63a and 63b switch the

capillary tubes

63 and 64 through which the refrigerant flows, and flow only through the capillary tube 63, flow through only the capillary tube 64, and neither of the

capillary tubes

63 and 64 flows. , 64 can be switched to four ways of distribution.

The

capillary tubes

63 and 64 and the

shutoff valves

63a and 64a may not be two sets as shown in FIG. 8, but may be one set or a plurality of sets of three or more. In the case of one set, the adjustment of the circulation amount of the refrigerant becomes coarse, and the adjustment of the circulation amount of the refrigerant becomes finer as the number of combinations increases. Further, when there is one capillary tube 63, the circulation of the refrigerant is not switched, and therefore the shutoff valve may be omitted.

Also, the secondary expansion device 43 in the first heat exchange unit 4 is not an expansion valve, but a capillary tube 65 that becomes a fixed pressure loss as in the above embodiment.

Further, in the refrigerant circuit 8a, the compressor 2, the second heat exchanger 7, the plurality of

capillary tubes

63 and 64, the expansion device 6 including the shut-off

valves

63a and 64a, the first heat exchange unit 4, and the compressor 2 are provided. The refrigerant circulates in this order. In the first heat exchange unit 4, the refrigerant from the expansion device 6 flows in the order of the first sub heat exchange unit 41, the sub expansion device 43 including the capillary tube 65, and the second sub heat exchange unit 42. Circulate.

The heat pump device 500 according to the sixth embodiment can only dissipate heat from the second heat exchanger 7 to the indoor air 12, and is a heating-only device. For this reason, normal cooling operation, high-temperature defrosting operation, and semi-high temperature defrosting operation cannot be performed, but normal heating operation and defrosting heating operation are possible in the same manner as in the above embodiment, and the same effects as in the above embodiment. Play. Further, since the expansion device 6 and the sub-expansion device 43 are not the expansion valve but are constituted by the

capillary tubes

63 and 64 and the capillary tube 65, the reliability is improved because the device is cheaper and smaller, and is less likely to fail. The

capillary tubes

63 and 64 and the capillary tube 65 have a narrower range of refrigerant flow or compression ratio than the expansion valve. However, if the heating and defrosting conditions are kept constant, the efficiency of the operating conditions can be improved. Reduction can be suppressed as much as possible.

In the sixth embodiment, as in the first, second, and third embodiments, either one or both of the expansion device 6 and the sub expansion device 43 has a variable flow rate or compression ratio range. A wide expansion valve may be used. In addition, any one or both of the expansion device 6 and the sub expansion device 43 in the first, second, and third embodiments may be a capillary tube. In this case, an inexpensive, small, and highly reliable heat pump device is realized. be able to.

In addition, the bypass valve 62 and the

shutoff valves

63a and 64a may substitute two of these as three-way valves. Thus, in the refrigerant circuit 8a, any piping or valve may be used as long as the distribution path can be switched.

Embodiment 7 FIG.
Next, the heat pump apparatus 600 according to the seventh embodiment will be described. FIG. 9 is a schematic diagram showing a heat pump device 600 according to the seventh embodiment. The seventh embodiment is different from the first embodiment in that the heat pump device 600 is applied to the refrigerator 601. In the seventh embodiment, portions common to the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and differences from the first embodiment will be mainly described.

In the first to sixth embodiments, the heat pump device is applied to an air conditioner that transports heat between the outdoor air 11 and the indoor air 12 by the refrigerant circuit 8 to cool and heat the room. In Embodiment 7, an example in which the heat pump device 600 is applied to a refrigerator 601 that stores food or the like at a low temperature will be described. The refrigerator 601 uses the refrigerant circuit 8 to perform defrosting in the cooling unit 104 that is the first heat exchange unit 4.

As shown in FIG. 9, in the refrigerator 601, in order to cool the inside 70 of the refrigerator 601, the inside air 51 and the inside air 52 (by the circulation fan 146 (equivalent to the ventilation fan 46 in the said embodiment)) ( The

outdoor air

11, 11a, 11b in the above embodiment passes through the circulation path 71 and passes between the interior 70 and the cooling unit 104 (corresponding to the first heat exchange unit 4 in the above embodiment). Circulate with. Further, in the cooling unit 104, a first cooler 141 (corresponding to the first sub heat exchange unit 41 in the above embodiment) and a second cooler 142 (second sub heat exchanger in the above embodiment) are provided. Corresponding to the heat exchanging section 42). The internal air 51 is cooled, that is, the temperature is lowered by heat exchange with the refrigerant flowing in the first cooler 141, and the internal air 52 flows in the second cooler 142. It is cooled, that is, the temperature is lowered by exchanging heat with the refrigerant.

Further, a partition plate 147 (corresponding to the partition plate 47 in the fourth embodiment) is provided between the first cooler 141 and the second cooler 142. Further, an air passage change means 72 that is, for example, a baffle plate is provided between the circulation fan 146 and the cooling unit 104 to open or block the air flow. The air passage changing means 72 can take three positions.

When the air passage change means 72 is at the position 72a, the air passage to the first cooler 141 is shielded and the circulation of the internal air 51 is interrupted. Moreover, when the ventilation path change means 72 exists in the position 72b, the air path to the 2nd cooler 142 is shielded, and the distribution | circulation of the internal air 52 is interrupted | blocked. Here, since the partition plate 147 is provided between the first cooler 141 and the second cooler 142, the air path is appropriately shielded. Further, when the air passage change means 72 is located at the position 72c, the air passages to both the first cooler 141 and the second cooler 142 are opened, and the distribution of the internal air 51 and the internal air 52 is performed. The first cooler 141 and the second cooler 142 are cooled.

Moreover, the refrigerator 601 is provided with a radiator (not shown) for radiating the heat of the interior 70 to the outside, and this radiator is the second heat exchanger in the above embodiment. It corresponds to 7. Note that the radiator in the refrigerator 601 may be replaced with a refrigerant pipe routed along the inside of the external wall surface of the refrigerator 601 instead of a so-called heat exchanger. Further, in the refrigerator 601, the in-compartment air 51 and the in-compartment air 52 once cooled by the cooling unit 104 are supplied to the inside 70 and then circulated back to the cooling unit 104 by the circulation path 71. Although different from the air conditioner in the above embodiment, the refrigerant circuit (not shown) through which the refrigerant flows is the same as the air conditioner in the above embodiment.

In the refrigerator 601, the cooling unit 104 only needs to cool the internal air 51 and the internal air 52. Therefore, at least the normal cooling operation (second heat exchanger in the above embodiment) is used as the refrigerant flow. 7 may absorb the heat and cool the indoor air 12). Thereby, it can suppress that the condensed water by which the indoor air 12 outside the warehouse was cooled adheres to the wall surface etc. outside the warehouse.

Next, the operation of the refrigerator 601 according to the seventh embodiment will be described. In the normal cooling operation (corresponding to the normal heating operation in the above embodiment), the air passage change means 72 is arranged at the position 72c in a state where the circulation fan 146 is operated, and the first cooler 141 and the second cooler 141 Both the internal air 51 and the internal air 52 are cooled by the cooler 142.

In the defrost cooling operation for defrosting only the first cooler 141 (corresponding to the defrost heating operation in the above embodiment), the refrigerant flow in the refrigerant circuit is the first auxiliary heat exchange in the above embodiment. It is the same as the case where only the part 41 is defrosted, and the ventilation path change means 72 is arrange | positioned in the position 72a. At this time, since the circulation fan 146 continues to blow air, the internal air 52 is cooled by the second cooler 142. As a result, although the cooling amount is inferior to that in the normal cooling operation, the cooling of the interior 70 can be continued. Moreover, the 1st cooler 141 is defrosted by heat exchange with the refrigerant | coolant which returned from the heat radiator. At this time, even if heat leaks into the internal air 51, the flow of the internal air 51 is blocked by the air passage changing means 72, so the heat leaking into the internal space 70 is extremely small.

In the defrost cooling operation for defrosting only the second cooler 142 (corresponding to the defrost heating operation in the above embodiment), the refrigerant flow in the refrigerant circuit is the second auxiliary heat exchange in the above embodiment. It is the same as the case where only the part 42 is defrosted, and the ventilation path change means 72 is arrange | positioned in the position 72b. At this time, since the circulation fan 146 continues to blow, the internal air 51 is cooled by the first cooler 141. As a result, although the cooling amount is inferior to that in the normal cooling operation, the cooling of the interior 70 can be continued. Moreover, the 2nd cooler 142 is defrosted by heat exchange with the refrigerant | coolant which returned from the heat radiator. At this time, even if heat leaks into the internal air 52, the flow of the internal air 52 is blocked by the air passage changing means 72, so the heat leaking into the internal space 70 is extremely small.

Thus, the refrigerator 601 including a plurality of coolers can continue cooling the interior 70 with the other cooler while defrosting one cooler. For this reason, the refrigerator 601 can maintain the temperature of the interior 70 of the refrigerator 601 low even during defrosting, and can maintain the quality of food stored in the interior 70. In addition, the refrigerator 601 according to the seventh embodiment has a reduced risk of failure due to fewer necessary switching valves, piping configurations, operation mode switching, and the like as compared to the showcase of Patent Document 2. Reliability is improved. Further, the operation method is simplified, and a small refrigerator 601 can be realized at low cost.

Further, in the defrost cooling operation, since the air blowing is changed by the air passage changing means 72, the heat generated during the defrosting is appropriately prevented from leaking into the interior 70. Thereby, in the refrigerator 601, it can defrost and cool efficiently.

(Modification)
In the seventh embodiment, one air passage changing means 72 is used to switch whether the internal air 51 and the internal air 52 are circulated to one cooler or both coolers. However, a plurality of air passage changing means 72 may be used. In this case, an air passage changing means 72 that can be opened and closed is provided for each cooler, and the internal air 51 and the internal air 52 are circulated to one cooler or both coolers. Can be switched.

Moreover, in the said Embodiment 7, using the baffle board as the ventilation path change means 72, whether the internal air 51 and the internal air 52 are distribute | circulated to one cooler or both coolers. However, instead of using a baffle plate, a blower fan may be provided for each cooler, and the blower path changing means 72 may be realized by switching the operation or stop of the blower fan. In this case, by switching the operation or stop of the blower fan, it is switched whether the internal air 51 and the internal air 52 are circulated to one cooler or both coolers.

Furthermore, in the said Embodiment 7, although the several cooler was arrange | positioned in parallel with respect to the flow of the internal air 51 and the internal air 52, Embodiment 5 (FIG. 5), implementation was shown. Like the form 6 (FIG. 6), the cooler may be arranged in series with respect to the flow of the internal air 51 and the internal air 52. Furthermore, as in the sixth embodiment, the heating means 48 is provided in the cooler on the downstream side, and also in the refrigerant circuit, the refrigerant circuit 8a (FIG. 8) in which the pressure feeding switching unit 3 and the inflow switching unit 5 are omitted. You may comprise as follows. In this case, the upstream cooler is defrosted using the refrigerant, and the downstream cooler is defrosted using the heating means 48. Thereby, since the refrigerator 601 can suppress a number of parts, it becomes smaller and low-cost, can suppress the risk of failure, and can improve reliability.

1 heat pump device, 2 compressor, 3 pumping switching unit, 4-1, 4-1, 4-2 1st heat exchange unit, 4a 1st distribution path, 4b 2nd distribution path, 5 inflow switching unit, 6 expansion Device, 7 second heat exchanger, 8, 8a refrigerant circuit, 9 temperature detector, 10 temperature detector, 11, 11a, 11b outdoor air (air), 11c forward direction, 11d reverse direction, 12 indoor air, 13 Temperature detection unit, 21 control unit, 22 defrosting control unit, 23 threshold determination unit, 24 end determination unit, 41, 41-1, 41-2 first auxiliary heat exchange unit, 41a, 41a-1, 41a- 2 1st temperature detection part, 42, 42-1 and 42-2 2nd sub heat exchange part, 42a, 42a-1, 42a-2 2nd temperature detection part, 43, 43-1 and 43-2 Sub-expansion device, 44, 44-1, 4-2 Sub bypass circuit, 44a First sub bypass circuit, 44b Second sub bypass circuit, 45, 45-1, 45-2 Sub bypass valve, 45a First sub bypass valve, 45b Second sub bypass Valve, 46, blower fan, 46a first blower fan, 46b second blower fan, 47 partition plate, 48 heating means, 49 plate fin, 50 refrigerant pipe, 51, 52 internal air, 61 bypass circuit, 62 bypass Valve, 63 capillary tube, 63a shutoff valve, 64 capillary tube, 64a shutoff valve, 65 capillary tube, 70 inside, 71 circulation path, 72 air passage change means, 72a, 72b, 72c position, 100 heat pump device, 104 cooling unit 141, first cooler, 142, second cooler, 14 Circulating fan, 147 partition plate 200 heat pump apparatus, 300 a heat pump apparatus, 400 a heat pump apparatus, 500 a heat pump apparatus, 600 a heat pump apparatus, 601 a refrigerator.

Claims

In a heat pump device having a refrigerant circuit in which a compressor, a first heat exchange unit, an expansion device, and a second heat exchanger are connected by piping and through which refrigerant flows, and a control unit that controls the operation of the refrigerant circuit. ,
The first heat exchange unit includes:
A plurality of auxiliary heat exchange units connected in series;
A secondary expansion device provided between the plurality of secondary heat exchange units,
The controller is
When defrosting the sub heat exchanger, the sub expansion device is configured such that a difference is generated between the pressure of the refrigerant flowing upstream of the sub expansion device and the pressure of the refrigerant flowing downstream of the sub expansion device. A heat pump device comprising defrosting control means for controlling the defrosting.
The refrigerant circuit is
The heat pump device according to claim 1, further comprising a pressure feed switching unit that switches a flow direction of the refrigerant in the refrigerant circuit.
The refrigerant circuit is
The heat pump device according to claim 1, further comprising an inflow switching unit that switches a flow direction of the refrigerant in the first heat exchange unit.
The refrigerant circuit is
A bypass circuit for bypassing the expansion device;
The heat pump device according to any one of claims 1 to 3, further comprising a bypass valve provided in the bypass circuit and configured to adjust a flow rate of the refrigerant in the bypass circuit.
The defrosting control means includes
The heat pump device according to claim 4, wherein the defrost valve is opened when defrosting the auxiliary heat exchange unit.
The defrosting control means includes
The heat pump device according to any one of claims 1 to 5, wherein the sub-expansion device is controlled based on a condensation temperature of the refrigerant in the refrigerant circuit.
The defrosting control means includes
The heat pump device according to any one of claims 1 to 6, wherein the sub-expansion device is controlled based on a discharge temperature of the refrigerant in the refrigerant circuit.
A blower fan that blows air that exchanges heat with the refrigerant flowing through the first heat exchange unit to the first heat exchange unit;
Air passage changing means for opening or shutting off the flow of air, and
The defrosting control means includes
The air flow is opened or blocked by the blowing path changing means so as to change whether or not the air blown in the blower fan flows for each of the plurality of auxiliary heat exchange units. 8. The heat pump device according to any one of 1 to 7.
A fan for blowing air to the first heat exchange unit with air that exchanges heat with the refrigerant flowing through the first heat exchange unit;
The blower fan is
The heat pump device according to any one of claims 1 to 7, wherein the heat pump device is individually provided for each of the plurality of sub heat exchange units.
A fan for blowing air to the first heat exchange unit with air that exchanges heat with the refrigerant flowing through the first heat exchange unit;
The plurality of auxiliary heat exchange units are arranged in series with respect to the blowing direction of the air blown in the blower fan,
The auxiliary heat exchange unit arranged on the upstream side with respect to the flow direction of the refrigerant flowing through the auxiliary expansion device,
The heat pump device according to any one of claims 1 to 7, wherein the heat pump device is disposed upstream of a blowing direction of air blown by the blower fan.
The blower fan is
The air blowing direction can be switched in both directions,
The defrosting control means includes
When defrosting the sub heat exchange unit, the sub heat exchange unit disposed on the upstream side with respect to the flow direction of the refrigerant flowing through the sub expansion device is directed toward the air blowing direction of the air blown by the blower fan. The heat pump device according to claim 10, wherein the air blowing direction in the blower fan is switched so as to be positioned on the upstream side.
Provided in the auxiliary heat exchange section, further comprising a heating means for heating the auxiliary heat exchange section;
The controller is
The heat pump device according to claim 10 or 11, wherein the heating unit heats the auxiliary heat exchange unit positioned downstream with respect to a blowing direction of air blown by the blower fan.
The defrosting control means includes
The heat pump device according to any one of claims 8 to 12, wherein when the sub heat exchange unit is defrosted, the blower fan is stopped or the rotational speed of the blower fan is reduced.
The refrigerant circuit is
A temperature detection unit for detecting the temperature of the refrigerant;
The controller is
Threshold determination means for determining whether the temperature of the refrigerant detected by the temperature detection unit is equal to or higher than a predetermined threshold;
An end determination for determining that the defrosting of the auxiliary heat exchange unit is completed when the threshold determination unit determines that the temperature of the refrigerant is equal to or higher than the threshold while defrosting the auxiliary heat exchange unit. The heat pump device according to any one of claims 1 to 13, further comprising: means.
The refrigerant circuit is
A sub-bypass circuit that bypasses the sub-inflator;
A sub bypass valve that is provided in the sub bypass circuit and adjusts a refrigerant flow rate in the sub bypass circuit;
The defrosting control means includes
The heat pump device according to any one of claims 1 to 14, wherein the sub bypass valve is closed when any of the plurality of sub heat exchange units is defrosted.
In the auxiliary heat exchange part,
A plurality of distribution channels through which the refrigerant branches and distributes are formed,
The heat pump device according to claim 15, wherein the sub bypass circuit and the sub bypass valve are provided for each of the plurality of distribution paths.
The secondary expansion device is
The heat pump device according to any one of claims 1 to 16, wherein the heat pump device comprises an expansion valve that adjusts a flow rate of the refrigerant.
The secondary expansion device is
The heat pump device according to any one of claims 1 to 17, wherein the heat pump device comprises a capillary tube.