JPWO2016207947A1 - Air conditioner - Google Patents

Abstract

An object of the present invention is to obtain an air conditioner that suppresses the occurrence frequency of noise increase in an outdoor fan. When the outdoor temperature is higher than the reference temperature and the operating capacity of the indoor unit is less than the reference capacity, the control unit executes liquid leveling control within the range of the maximum operating output during normal operation of the blower. If the outdoor temperature is lower than the reference temperature, or if the outdoor temperature is higher than the reference temperature and the indoor unit operating capacity is higher than the reference capacity, increase the blower from the maximum operating output during normal operation. Liquid leveling control is executed.

Description

  The present invention relates to an air conditioner in which a plurality of outdoor units are connected to an indoor unit through a single refrigerant system, and more particularly to an air conditioner that equalizes the amount of refrigerant in each outdoor unit.

  In order to respond to an increase in capacity of an air conditioner, an air conditioner including a plurality of outdoor units has been developed. In such an air conditioner including a plurality of outdoor units, there may be a refrigerant bias between the outdoor units due to various factors. Therefore, conventionally, an air conditioner has been proposed that corrects (evens out) the refrigerant bias occurring between the outdoor units.

  For example, an air conditioner described in Patent Document 1 includes a plurality of outdoor units equipped with a compressor, a four-way switching valve, a heat exchanger, and an accumulator, and calculates the degree of superheat of the refrigerant flowing out of the heat exchanger. The heat exchanger outlet superheat degree calculating means and the compressor discharge superheat degree calculating means for calculating the superheat degree of the refrigerant discharged from the compressor are provided. Further, the air conditioner determines an imbalance in the amount of liquid refrigerant in the accumulator based on the calculated values of the heat exchanger outlet superheat degree calculating means and the compressor discharge superheat degree calculating means, and executes liquid equalization control. Liquid equalization control means is provided.

  The air conditioner is provided with a blower for supplying air to the heat exchanger in the outdoor unit, and the liquid leveling control means includes a heat exchanger outlet superheat degree calculating means and a compressor discharge superheat degree calculating means. The operation output of the blower is controlled based on the calculated value. Furthermore, the liquid leveling control means of the air conditioner converges the superheat degree of the refrigerant flowing out of the heat exchanger and the superheat degree of the refrigerant discharged from the compressor to a preset reference value. Control is being executed.

JP 2008-249259 A

  In the refrigerant leveling control described in Patent Document 1, the leveling control is performed using a blower for supplying air to the heat exchanger. Specifically, the liquid leveling control means of the air conditioner performs the liquid leveling control by decreasing the air volume of one blower of the air conditioners connected to two or more units and increasing the air volume of the other fan. Yes. By the way, when performing this liquid leveling control, it is necessary to increase the air volume of one blower from the normal time depending on the load applied to the air conditioner. However, since the noise of the outdoor unit increases when the air volume of one blower is increased from the normal time, in order to avoid this, it is necessary to further reduce the air volume of the other blower. However, if the air volume of the other blower is further reduced, the operating capacity of the air conditioner will be reduced. Therefore, in order to avoid a decrease in the operating capacity of this air conditioner, it is necessary to increase the air volume of the blower to perform liquid leveling control, but when the liquid leveling control is performed to always increase the air volume of the air blower than usual. There was a problem that the noise of the outdoor unit increased.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to obtain an air conditioner that suppresses an increase in the noise of a blower of an outdoor unit when equalizing the refrigerant amount of each outdoor unit. Objective.

  An air conditioner according to the present invention is an air conditioner including a plurality of outdoor units equipped with a compressor, a heat source side heat exchanger, and a blower, and an indoor unit equipped with an indoor side heat exchanger. In the heating operation or the heating main operation, the plurality of outdoor units are obtained from a first superheat degree of the refrigerant flowing out from the heat source side heat exchanger and a second superheat degree of the refrigerant discharged from the compressor. When it is determined that a refrigerant amount imbalance has occurred, the operation output of the outdoor unit blower with the larger refrigerant amount is increased, and the operation output of the outdoor unit blower with the smaller refrigerant amount is decreased. A control unit that performs liquid leveling control, and when the outdoor temperature is higher than the reference temperature and the operation capacity of the indoor unit is less than the reference capacity, the control unit operates the fan normally. Leveling within the range of the maximum operating output When the outdoor temperature is equal to or lower than the reference temperature, or when the outdoor temperature is higher than the reference temperature and the operating capacity of the indoor unit is equal to or higher than the reference capacity, the maximum operation output during normal operation of the blower is performed. The liquid leveling control is executed by increasing the value.

  According to the present invention, when the outdoor temperature is greater than a predetermined value and the operation capacity of the indoor unit is less than the predetermined value, the control unit sets the blower to an operation output during normal operation and performs liquid leveling control. When the outdoor temperature is lower than a predetermined value, or when the outdoor temperature is higher than a predetermined value and the operating capacity of the indoor unit is higher than a predetermined value, the fan is operated based on the operation output during normal operation. Increase the liquid leveling control. By doing in this way, since it becomes impossible to always increase the maximum value of the operation output of an air blower, the air conditioning apparatus which can suppress the noise increase of the air blower of an outdoor unit can be obtained.

1 is a schematic refrigerant circuit diagram of an air conditioner according to an embodiment of the present invention. It is a refrigerant circuit figure at the time of the heating operation of the air conditioning apparatus which concerns on embodiment of this invention. It is a flowchart which concerns on control operation of the control part at the time of the heating operation of the air conditioning apparatus which concerns on embodiment of this invention.

  Embodiments of an air conditioner according to the present invention will be described below with reference to the drawings. In addition, the form of drawing is an example and does not limit this invention. Moreover, what attached | subjected the same code | symbol in each figure is the same or it corresponds, and this is common in the whole text of a specification. Furthermore, in the following drawings, the relationship between the sizes of the constituent members may be different from the actual one.

Embodiment.
[Description of refrigerant circuit of air conditioner]
FIG. 1 is a schematic refrigerant circuit diagram of an air-conditioning apparatus according to an embodiment of the present invention. Based on FIG. 1, the structure of the refrigerant circuit of the air conditioning apparatus 500 is demonstrated. The air conditioner 500 performs a cooling operation and a heating operation using a refrigeration cycle (heat pump cycle) for circulating a refrigerant. As shown in FIG. 1, the air conditioner 500 includes an outdoor unit 51 and an outdoor unit 151 as heat source side units, and includes an indoor unit 53a and an indoor unit 53b as load side units. The outdoor unit 51 and the outdoor unit 151 are connected to the flow dividing controller 52 by the low pressure pipe 201 and the high pressure pipe 202, and further connected in parallel to the indoor unit 53a and the indoor unit 53b from the flow dividing controller 52 to constitute a refrigeration cycle circuit. Yes. Moreover, the air conditioning apparatus 500 is provided with the control part 20 mentioned later. Note that the air conditioner 500 illustrated in FIG. 1 is merely an example, and may include three or more outdoor units, or one or three or more indoor units.

  The outdoor unit 51 includes a compressor 1, a heat source side heat exchanger 2, a four-way valve 3, an accumulator 4, check valves 5 a, 5 b, 5 c, 5 d, and a blower 6. The outdoor unit 51 includes a high pressure detection unit 31, a low pressure detection unit 32, a compressor discharge temperature detection unit 34, a heat exchanger outlet temperature detection unit 35, an outside air temperature detection unit 36, and a compressor discharge superheat degree calculation unit 37. The heat exchanger outlet superheat degree calculating means 38 and the indoor unit operating capacity calculating means 41 are provided.

  The compressor 1 sucks the refrigerant and compresses the refrigerant to a high temperature and high pressure state. A four-way valve 3 is connected to the discharge side of the compressor 1. The four-way valve 3 switches the flow path of the refrigerant discharged from the compressor 1 to a flow path that flows to the heat source side heat exchanger 2 or a flow path that flows to the indoor unit 53a and the indoor unit 53b. The four-way valve 3 is also connected to the accumulator 4 so that the refrigerant flowing from the heat source side heat exchanger 2 or the indoor unit 53a and the indoor unit 53b is sent to the accumulator 4.

  In this embodiment, a four-way valve is exemplified as the flow path switching valve. However, the present invention is not limited to this, and for example, a two-way valve or a three-way valve may be combined.

  The blower 6 is configured by a fan or the like, and has a function for blowing air to the heat source side heat exchanger 2. The accumulator 4 stores excess refrigerant, and is a container that can store excess refrigerant. In addition, although the example which provided the accumulator 4 in the air conditioning apparatus 500 in this Embodiment was shown, the accumulator 4 does not need to be provided depending on the usage condition of the air conditioning apparatus 500.

  As with the compressor 1, the outdoor unit 151 includes a compressor 101, a heat source side heat exchanger 102, a four-way valve 103, an accumulator 104, check valves 105 a, 105 b, 105 c, 105 d, and a blower 106. The outdoor unit 151 includes a high pressure detection unit 131, a low pressure detection unit 132, a compressor discharge temperature detection unit 134, a heat exchanger outlet temperature detection unit 135, an outside air temperature detection unit 136, and a compressor discharge superheat degree calculation unit 137. The heat exchanger outlet superheat degree calculating means 138 and the indoor unit operating capacity calculating means 141 are provided.

  The compressor 101 sucks the refrigerant and compresses the refrigerant to a high temperature and high pressure state. A four-way valve 103 is connected to the discharge side of the compressor 101. The four-way valve 103 switches the flow path of the refrigerant discharged from the compressor 101 to a flow path that flows to the heat source side heat exchanger 102, or a flow path that flows to the indoor unit 53a and the indoor unit 53b. The four-way valve 103 is also connected to the accumulator 104 so that the refrigerant flowing from the heat source side heat exchanger 102 or the indoor unit 53a and the indoor unit 53b is sent to the accumulator 104.

  In this embodiment, a four-way valve is exemplified as the flow path switching valve. However, the present invention is not limited to this, and for example, a two-way valve or a three-way valve may be combined.

  The blower 106 is configured by a fan or the like, and has a function for blowing air to the heat source side heat exchanger 102. The accumulator 104 stores excess refrigerant and is a container that can store excess refrigerant. In the present embodiment, the example in which the accumulator 4 is provided in the air conditioner 500 has been described. However, the accumulator 104 may not be provided depending on the use mode of the air conditioner 500.

  The four-way valve 3 and the four-way valve 103 perform switching of valves corresponding to the mode (mode) of the cooling / heating operation so that the refrigerant path is switched. In the present embodiment, during the cooling only operation (referred to here as the operation when all the indoor units performing air conditioning are cooling), during the cooling main operation (of the simultaneous cooling and heating operation, the cooling load is Large operation), heating operation (here, operation when all air-conditioned indoor units are heating), heating operation (heating and cooling among simultaneous heating and cooling operations) The route is switched by a large driving).

  The heat source side heat exchanger 2 and the heat source side heat exchanger 102 have heat transfer tubes that allow the refrigerant to pass therethrough and fins for increasing the heat transfer area between the refrigerant flowing through the heat transfer tubes and the outside air, Exchange heat with air (outside air). For example, it functions as an evaporator during the heating only operation or during the heating main operation, and evaporates the refrigerant, for example. On the other hand, it functions as a condenser during the cooling only operation or during the cooling main operation, for example, condenses and liquefies the refrigerant. In some cases, adjustment is performed such as condensing to a state of two-phase mixing (gas-liquid two-phase state) of liquid and gas, instead of being completely gasified or liquefied, for example, at the time of cooling main operation. .

  The air conditioner 500 according to the present embodiment includes an outdoor unit 51, an outdoor unit 151, an indoor unit 53a, an indoor unit 53b, and a shunt controller 52. In the present embodiment, in order to control the flow of the refrigerant, a shunt controller 52 is provided between the outdoor unit 51, the outdoor unit 151 and the indoor unit 53a, and the indoor unit 53b, and piping between these devices is made by various refrigerant pipes. Connecting. Further, the plurality of indoor units 53a and 53b are connected so as to be parallel to each other. For example, in the indoor unit 53a, the indoor unit 53b, and the like, when there is no need to particularly distinguish or specify, the a and b suffixes are omitted and referred to as the indoor unit 53. Moreover, although the example which provided the shunt controller 52 in the air conditioning apparatus 500 in this Embodiment was shown, depending on the usage condition of the air conditioning apparatus 500, it is not necessary to provide the shunt controller 52. FIG.

  Regarding the pipe connection, the outdoor unit 51, the outdoor unit 151 and the shunt controller 52 are connected by a low pressure pipe 201 and a high pressure pipe 202. Here, a refrigerant branch point 19 is provided between the outdoor unit 51 and the outdoor unit 151 and the low pressure pipe 201 to branch the refrigerant from the low pressure pipe 201 and guide the refrigerant to the outdoor unit 51 and the outdoor unit 151. ing. On the other hand, a refrigerant junction 18 is provided between the outdoor unit 51 and the outdoor unit 151 and the high-pressure pipe 202 to join the refrigerant from the outdoor unit 51 and the outdoor unit 151 and guide the refrigerant to the high-pressure pipe 202. In the high-pressure pipe 202, high-pressure refrigerant flows from the outdoor unit 51 and outdoor unit 151 side to the shunt controller 52 side. Further, in the low-pressure pipe 201, a refrigerant having a pressure lower than that flowing through the high-pressure pipe 202 flows from the shunt controller 52 side to the outdoor unit 51 and the outdoor unit 151. Here, the level of the pressure is not determined by the relationship with the reference pressure (numerical value), but the pressurization of the compressor 1 and the compressor 101 and the opening / closing of each throttle device (flow rate limiting device) ( It is assumed that it is expressed based on relative elevation (including the middle) in the refrigerant circuit by controlling the (opening) state.

  On the other hand, the diversion controller 52 and the indoor unit 53a are connected by a liquid pipe 203a and a gas pipe 204a. Similarly, the indoor unit 53b is connected by a liquid pipe 203b and a gas pipe 204b. In addition, when not distinguishing especially the liquid pipe 203a and the liquid pipe 203b, it will be called the liquid pipe 203. Similarly, when not distinguishing especially the gas pipe 204a and the gas pipe 204b, it will be called the gas pipe 204. By piping connection by the low pressure pipe 201, the high pressure pipe 202, the liquid pipe 203, and the gas pipe 204, the refrigerant circulates between the outdoor unit 51, the outdoor unit 151, the shunt controller 52, and the indoor unit 53, thereby forming a refrigerant circuit.

  The check valves 5a, 5b, 5c, and 5d of the outdoor unit 51 prevent the refrigerant from flowing back to regulate the flow of the refrigerant and make the refrigerant circulation path constant according to the operation mode. The check valve 5 a is located on the pipe between the four-way valve 3 and the low-pressure pipe 201, and allows the refrigerant flow from the low-pressure pipe 201 toward the four-way valve 3. The check valve 5 b is located on the pipe between the heat source side heat exchanger 2 and the low pressure pipe 201 and allows the refrigerant flow from the low pressure pipe 201 toward the heat source side heat exchanger 2. The check valve 5 c is located on the pipe between the four-way valve 3 and the high-pressure pipe 202 and allows the refrigerant flow from the four-way valve 3 to the high-pressure pipe 202. The check valve 5 d is located on the pipe between the heat source side heat exchanger 2 and the high pressure pipe 202 and allows the refrigerant flow from the heat source side heat exchanger 2 toward the high pressure pipe 202.

  Similarly, the check valves 105a, 105b, 105c, and 105d of the outdoor unit 151 prevent the refrigerant from flowing backward to regulate the flow of the refrigerant and make the refrigerant circulation path constant according to the mode. The check valve 105 a is located on the pipe between the four-way valve 103 and the low-pressure pipe 201, and allows the refrigerant flow from the low-pressure pipe 201 toward the four-way valve 103. The check valve 105 b is located on the pipe between the heat source side heat exchanger 102 and the low pressure pipe 201 and allows the refrigerant flow from the low pressure pipe 201 toward the heat source side heat exchanger 102. The check valve 105 c is located on the pipe between the four-way valve 103 and the high-pressure pipe 202 and allows the refrigerant flow from the four-way valve 103 to the high-pressure pipe 202. The check valve 105 d is located on a pipe between the heat source side heat exchanger 102 and the high pressure pipe 202, and allows the refrigerant flow from the heat source side heat exchanger 102 to the high pressure pipe 202.

  A high pressure detecting means 31 for detecting the pressure of the refrigerant is attached on the discharge side of the compressor 1, and on the suction side of the compressor 1, on the outlet side of the heat source side heat exchanger 2 during heating operation. Low pressure detection means 32 for detecting the pressure of the refrigerant is attached. Further, the outdoor unit 51 is provided with a compressor discharge temperature detecting means 34 for detecting the temperature of the refrigerant on the high pressure side (discharge side) of the compressor 1. Further, the outdoor unit 51 is provided with heat exchanger outlet temperature detection means 35 for detecting the temperature of the refrigerant on the outlet side of the heat source side heat exchanger 2 during the heating operation. The outdoor unit 51 is provided with an outside air temperature detecting means 36 that detects the outside air temperature around the outdoor unit 51. The high pressure detection means 31 and the low pressure detection means 32 are constituted by a pressure sensor or the like. The compressor discharge temperature detection means 34, the heat exchanger outlet temperature detection means 35, and the outside air temperature detection means 36 are constituted by temperature sensors such as a thermistor.

  Further, the outdoor unit 51 includes a compressor discharge superheat degree calculation means 37, a heat exchanger outlet superheat degree calculation means 38, and an indoor unit operation capacity calculation means 41, which are constituted by, for example, a microcomputer. The compressor discharge superheat degree calculation means 37 calculates the superheat degree of the refrigerant discharged from the compressor 1. The heat exchanger outlet superheat degree calculation means 38 calculates the superheat degree of the refrigerant flowing out from the heat source side heat exchanger 2. In addition, the indoor unit operating capacity calculating means 41 calculates the operating capacity of the indoor unit 53. In addition, the outdoor unit 51 is connected to the control unit 20 described later. The control unit 20 is configured by a microcomputer, for example. In the present embodiment, an example has been shown in which the outdoor unit 51 is provided with the compressor discharge superheat degree calculation means 37, the heat exchanger outlet superheat degree calculation means 38, and the indoor unit operating capacity calculation means 41. The invention is not limited to this, and a computing unit in which the above computing units are combined into one may be provided, or a computing unit may be provided separately.

  A high pressure detecting means 131 for detecting the pressure of the refrigerant is mounted on the discharge side pipe of the compressor 101, and on the suction side pipe of the compressor 101, on the outlet side of the heat source side heat exchanger 102 during heating operation. Low pressure detection means 132 for detecting the pressure of the refrigerant is attached. Further, the outdoor unit 151 is provided with a compressor discharge temperature detecting means 134 for detecting the temperature of the refrigerant on the high pressure side (discharge side) of the compressor 101. Further, the outdoor unit 151 is provided with heat exchanger outlet temperature detection means 135 for detecting the temperature of the refrigerant on the outlet side of the heat source side heat exchanger 102 during the heating operation. The outdoor unit 151 is provided with an outside air temperature detection unit 136 that detects the outside air temperature around the outdoor unit 151. The high pressure detection means 131 and the low pressure detection means 132 are constituted by pressure sensors or the like. The compressor discharge temperature detection means 134, the heat exchanger outlet temperature detection means 135, and the outside air temperature detection means 136 are constituted by temperature sensors such as a thermistor.

  Further, the outdoor unit 151 includes a compressor discharge superheat degree calculation means 137, a heat exchanger outlet superheat degree calculation means 138, and an indoor unit operation capacity calculation means 141, which are constituted by a microcomputer, for example. The compressor discharge superheat degree calculation means 137 calculates the superheat degree of the refrigerant discharged from the compressor 101. The heat exchanger outlet superheat degree calculation means 138 calculates the superheat degree of the refrigerant flowing out from the heat source side heat exchanger 102. Further, the indoor unit operating capacity calculating means 141 calculates the operating capacity of the indoor unit 53. In addition, the outdoor unit 151 is connected to a control unit 20 described later. In the present embodiment, an example is shown in which the outdoor unit 151 is provided with the compressor discharge superheat degree calculation means 137, the heat exchanger outlet superheat degree calculation means 138, and the indoor unit operating capacity calculation means 141. The invention is not limited to this, and a computing unit in which the above computing units are combined into one may be provided, or a computing unit may be provided separately.

  Next, the shunt controller 52 will be described. The gas-liquid separator 11 included in the shunt controller 52 separates the refrigerant flowing from the high pressure pipe 202 into a gas refrigerant and a liquid refrigerant. A gas phase portion (not shown) through which the gas refrigerant flows is connected to the electromagnetic valve 12a and the electromagnetic valve 12b. On the other hand, the liquid phase part (not shown) from which the liquid refrigerant flows is connected to the inter-refrigerant heat exchanger 16.

  The solenoid valve 12a, the solenoid valve 12b, the solenoid valve 13a, and the solenoid valve 13b in the shunt controller open and close based on the operation mode. One end of the electromagnetic valve 12a is connected to the gas-liquid separator 11, and the other end is connected to the gas pipe 204a. One end of the electromagnetic valve 12b is connected to the gas-liquid separator 11, and the other end is connected to 204b. Further, one end of the electromagnetic valve 13a is connected to the gas pipe 204a, and the other end is connected to the low pressure pipe 201. One end of the electromagnetic valve 13b is connected to 204b, and the other end is connected to the low pressure pipe 201. By combining the solenoid valve 12a, the solenoid valve 12b, the solenoid valve 13a, and the solenoid valve 13b, the refrigerant flows from the indoor unit 53 side to the low pressure pipe 201 side based on the operation mode, or the gas-liquid separator 11 side The valve is switched so that the refrigerant flows from to the indoor unit 53 side. Here, the flow of the refrigerant is switched by the electromagnetic valve 12a, the electromagnetic valve 12b, the electromagnetic valve 13a, and the electromagnetic valve 13b. However, for example, a three-way valve or the like may be used.

  The expansion device 14 is provided between the inter-refrigerant heat exchanger 16 and the inter-refrigerant heat exchanger 17, controls the opening degree based on the operation mode of the cooling operation and the heating operation, and flows from the gas-liquid separator 11. Adjust the flow rate and refrigerant pressure. On the other hand, the expansion device 15 controls the opening and adjusts the refrigerant flow rate and the refrigerant pressure. As will be described later, the refrigerant that has passed through the expansion device 15 supercools the refrigerant flowing through the refrigerant heat exchanger 17 and the refrigerant heat exchanger 16 in the refrigerant heat exchanger 17 and the refrigerant heat exchanger 16, It flows to the low pressure pipe 201. It is assumed that the expansion device 14 and the expansion device 15 are composed of, for example, an electronic expansion valve that can change the opening degree.

  The inter-refrigerant heat exchanger 17 performs heat exchange between the refrigerant in the downstream portion of the expansion device 15 (the refrigerant that has passed through the expansion device 15) and the refrigerant that flows from the expansion device 14. The inter-refrigerant heat exchanger 16 exchanges heat between the refrigerant that has passed through the inter-refrigerant heat exchanger 17 and the liquid refrigerant that flows from the gas-liquid separator 11 toward the expansion device 14.

  Next, the configuration of the indoor unit 53a will be described. The indoor unit 53a includes an indoor side heat exchanger 22a and an indoor side expansion device 23a connected in series in proximity to the indoor side heat exchanger 22a. Similarly to the heat source side heat exchanger 2 described above, the indoor side heat exchanger 22a serves as an evaporator during the cooling operation and serves as a condenser during the heating operation, and between the air and the refrigerant in the air-conditioning target space. Perform heat exchange. Here, a blower for efficiently performing heat exchange between the refrigerant and the air may be provided in the vicinity of each indoor heat exchanger 22a.

  Similarly, the indoor unit 53b includes an indoor side heat exchanger 22b and an indoor side expansion device 23b connected in series in proximity to the indoor side heat exchanger 22b. Similarly to the heat source side heat exchanger 2 described above, the indoor side heat exchanger 22b serves as an evaporator during the cooling operation and serves as a condenser during the heating operation, and between the air and the refrigerant in the air-conditioning target space. Perform heat exchange. Here, a blower for efficiently performing heat exchange between the refrigerant and the air may be provided in the vicinity of each indoor heat exchanger 22b.

  Here, when the indoor side heat exchanger 22a and the indoor side heat exchanger 22b are not particularly distinguished, they are referred to as the indoor side heat exchanger 22, and similarly, the indoor side expansion device 23a and the indoor side expansion device 23b are not particularly distinguished. In this case, it is referred to as an indoor expansion device 23.

  The indoor expansion device 23 functions as a pressure reducing valve or an expansion valve, and adjusts the pressure of the refrigerant passing through the indoor heat exchanger 22. Here, it is assumed that the indoor side expansion device 23 is composed of, for example, an electronic expansion valve that can change the opening degree. The opening degree of the indoor expansion device 23 is determined based on the degree of superheat on the refrigerant outlet side (here, the gas pipe 204 side) of the indoor heat exchanger 22 during the cooling operation. Further, it is determined based on the degree of supercooling on the refrigerant outlet side (here, on the liquid pipe 203 side) during the heating operation.

  As described above, the air-conditioning apparatus 500 of the present embodiment configured as described above performs the operation in any one of the four modes (modes) of the cooling only operation, the heating only operation, the cooling main operation, and the heating main operation. It can be carried out.

[Explanation during heating operation]
Next, the operation of each device and the flow of refrigerant in the heating only operation will be described. Here, the case where all the indoor units 53 are heating without stopping will be described. FIG. 2 is a refrigerant circuit diagram during heating operation of the air-conditioning apparatus according to the embodiment of the present invention. The flow of the refrigerant during the all heating operation is indicated by solid arrows in FIG. As shown in FIG. 2, in the outdoor unit 51, the compressor 1 compresses the sucked refrigerant and discharges a high-pressure gas refrigerant. The refrigerant discharged from the compressor 1 flows through the four-way valve 3 and the check valve 5c (does not flow toward the check valve 5a and the check valve 5d), passes through the refrigerant confluence 18 and passes through the high-pressure pipe 202. Flow into the diversion controller 52.

  Similarly for the outdoor unit 151, the compressor 101 compresses the sucked refrigerant and discharges the high-pressure gas refrigerant. The refrigerant discharged from the compressor 101 flows through the four-way valve 103 and the check valve 105c (does not flow toward the check valve 105a and the check valve 105d). Then, the refrigerant merges with the refrigerant that has flowed out of the outdoor unit 51 at the refrigerant merge point 18, and flows into the diversion controller 52 through the high-pressure pipe 202.

  On the other hand, in the shunt controller 52, the solenoid valve 12a and the solenoid valve 12b are opened, and the solenoid valve 13a and the solenoid valve 13b are closed. Part of the gas refrigerant that has flowed into the shunt controller 52 passes through the gas-liquid separator 11, the electromagnetic valve 12a, and the gas pipe 204a, and flows into the indoor unit 53a. Similarly, the remaining gas refrigerant that has flowed into the flow dividing controller 52 passes through the gas-liquid separator 11, the electromagnetic valve 12b, and the gas pipe 204b, and flows into the indoor unit 53b.

  In the indoor unit 53, the flow rate of the refrigerant flowing through the indoor heat exchanger 22 is adjusted by adjusting the opening of the indoor expansion device 23. The high-pressure gas refrigerant is condensed by heat exchange while passing through the indoor heat exchanger 22, and becomes a liquid refrigerant, and passes through the indoor expansion device 23. At this time, the indoor air is heated by heat exchange to heat the air-conditioning target space (indoor).

  The refrigerant that has passed through the indoor expansion device 23 becomes, for example, an intermediate-pressure liquid refrigerant or a gas-liquid two-phase refrigerant, passes through the liquid pipe 203, flows into the inter-refrigerant heat exchanger 17, and then passes through the expansion device 15. The refrigerant that has been reduced in pressure after passing through the expansion device 15 flows into the low-pressure pipe 201, is distributed to the outdoor unit 51 side and the outdoor unit 151 side at the refrigerant branch point 19, and flows into the outdoor unit 51 and the outdoor unit 151, respectively.

  The refrigerant flowing into the outdoor unit 51 passes through the check valve 5b of the outdoor unit 51 and flows into the heat source side heat exchanger 2. Note that the refrigerant does not flow to the check valve 5a and check valve 5d side due to the pressure of the refrigerant. The refrigerant evaporates by heat exchange with air while passing through the heat source side heat exchanger 2, and becomes a gas refrigerant. Then, the refrigerant passes through the four-way valve 3 and the accumulator 4 and returns to the compressor 1 to be discharged again. This is the refrigerant circulation path during the all-heating operation.

  Similarly, the refrigerant flowing into the outdoor unit 151 passes through the check valve 105 b of the outdoor unit 151 and flows into the heat source side heat exchanger 102. Note that the refrigerant does not flow to the check valve 105a and the check valve 105d side due to the pressure of the refrigerant. The refrigerant evaporates by heat exchange with air while passing through the heat source side heat exchanger 102 and becomes a gas refrigerant. Then, the refrigerant passes through the four-way valve 103 and the accumulator 104 and returns to the compressor 101 to be discharged again. This is the refrigerant circulation path during the all-heating operation.

[Explanation of leveling control]
Next, liquid leveling control will be described. The air conditioner 500 having a plurality of outdoor units, such as the air conditioner 500 according to the present embodiment, has a refrigerant bias between the outdoor units due to various factors, particularly during heating operation or heating main operation. There is. There is a correlation between the refrigerant bias and the degree of superheat (compressor suction superheat) at the outlet of the heat source side heat exchanger and the discharge superheat degree of the compressor. That is, when the amount of refrigerant in the outdoor unit decreases, the degree of superheat at the outlet of the heat source side heat exchanger and the degree of discharge superheat of the compressor increase. In other words, when the amount of refrigerant in the outdoor unit increases, the degree of superheat at the outlet of the heat source side heat exchanger and the degree of discharge superheat of the compressor decrease.

  FIG. 3 is a flowchart relating to the control operation of the control unit during the heating operation of the air-conditioning apparatus according to the embodiment of the present invention. With reference to FIG. 1, the liquid equalization control during the heating operation of the air-conditioning apparatus according to the embodiment of the present invention will be described based on the steps in FIG.

(Step S30a)
As shown in the following equation (1), the heat exchanger outlet superheat degree calculation means 38 calculates the saturation temperature Te1 from the suction pressure (low pressure) detected by the low pressure detection means 32, and detects the heat exchanger outlet temperature. By subtracting the saturation temperature Te1 from the temperature Thex1 detected by the means 35, the heat exchanger outlet superheat degree HEXSH1 is obtained.
HEXSH1 = Thex1-Te1 (1)

Further, as shown in the following equation (2), the heat exchanger outlet superheat degree calculating means 138 calculates the saturation temperature Te2 from the discharge pressure (low pressure) detected by the low pressure detecting means 132, and the heat exchanger outlet By subtracting this saturation temperature Te2 from the temperature Thex2 detected by the temperature detection means 135, the heat exchanger outlet superheat degree HEXSH2 is obtained.
HEXSH2 = Thex2-Te2 (2)
Thereafter, the control unit 20 proceeds to (Step S30b).
In the present embodiment, the heat exchanger outlet superheat degree calculation means 38 and 138 are used to determine the heat exchanger outlet superheat degrees HEXSH1 and HEXSH2. However, the present invention is not limited to this, and the controller 20 obtains the heat exchanger outlet superheat degrees. May be. The heat exchanger outlet superheat degrees HEXSH1 and HEXSH2 correspond to the “first superheat degree” in the present invention.

(Step S30b)
As shown in the following equation (3), the compressor discharge superheat degree calculation means 37 calculates the saturation temperature Tc1 from the discharge pressure (high pressure) detected by the high pressure detection means 31, and the compressor discharge temperature detection means 34. By subtracting the saturation temperature Tc1 from the discharge temperature Td1 detected by the above, the discharge superheat degree TdSH1 of the compressor 1 is obtained.
TdSH1 = Td1-Tc1 (3)

Further, as shown in the following equation (4), the compressor discharge superheat degree calculation means 137 calculates the saturation temperature Tc2 from the discharge pressure (high pressure) detected by the high pressure detection means 131, and detects the compressor discharge temperature. The discharge superheat degree TdSH2 of the compressor 101 is obtained by subtracting the saturation temperature Tc2 from the discharge temperature Td2 detected by the means 134.
TdSH2 = Td2-Tc2 (4)
Thereafter, the control unit 20 proceeds to (Step S31).
In the present embodiment, an example has been shown in which the compressor discharge superheat degrees TdSH1 and TdSH2 are obtained by the compressor discharge superheat degree calculation means 37 and 137, but the present invention is not limited to this, and is obtained by the control unit 20. Also good. Further, the discharge superheat degrees TdSH1 and TdSH2 of the compressor correspond to the “second superheat degree” in the present invention.

  When the refrigerant is evenly distributed between the outdoor unit 51 and the outdoor unit 151, the relationship of TdSH1 = TdSH2 is ideally established. On the other hand, when there is a difference between the refrigerant holding amount in the outdoor unit 51 and the refrigerant holding amount in the outdoor unit 151, the discharge superheat degree TdSH1 of the compressor 1 and the compressor according to the refrigerant holding amount in the outdoor unit A difference occurs between the discharge superheat degree 101 of 101 and TdSH2. For example, when the refrigerant holding amount in the outdoor unit 151 is smaller than the refrigerant holding amount in the outdoor unit 51, TdSH1 <TdSH2.

(Step S31)
The control unit 20 determines whether or not the heat exchanger outlet superheat degree HEXSH1 and the heat exchanger outlet superheat degree HEXSH2 are both greater than a preset reference value A. When both the heat exchanger outlet superheat degree HEXSH1 and the heat exchanger outlet superheat degree HEXSH2 are larger than the reference value A set in advance, the control unit 20 proceeds to (Step S32). In this case, the process proceeds to (Step S33).

(Step S32)
The control unit 20 determines whether or not the discharge superheat degree TdSH1 of the compressor 1 and the discharge superheat degree TdSH2 of the compressor 101 are both larger than a preset reference value B. When the discharge superheat degree TdSH1 of the compressor 1 and the discharge superheat degree TdSH2 of the compressor 101 are both larger than the preset reference value B, the control unit 20 performs normal operation of the blower 6 and the blower 106. While performing, the process proceeds to (Step S31). In other cases, the process proceeds to (Step S33) to perform liquid leveling control.

(Step S33)
The control unit 20 acquires the temperature of the outside air sucked by the outdoor unit 51 and the outdoor unit 151 from the outside air temperature detection unit 36 and the outside air temperature detection unit 136, and determines whether or not the temperature of the outside air is higher than the reference temperature C. If the outside air temperature is higher than the reference temperature C, the control unit 20 proceeds to (Step S34), and otherwise, proceeds to (Step S36).

(Step S34)
The control unit 20 acquires information on the operating capacity of the indoor unit 53 from the indoor unit operating capacity calculating unit 41 and the indoor unit operating capacity calculating unit 141, and determines whether or not the operating capacity of the indoor unit 53 is smaller than the reference capacity D. To do. When the operation capacity of the indoor unit 53 is smaller than the reference capacity D, the control unit 20 proceeds to (Step S35), and otherwise, proceeds to (Step S36).

(Step S35)
The control unit 20 sets the maximum value of the operation output of the blower 6 and the blower 106 to E, which is the same value as the output of the blower during normal operation. Thereafter, the control unit 20 proceeds to (Step S39). In addition, the time of normal operation means the time of heating operation when liquid leveling control is not performed, and the maximum output of the blower in that case is the maximum value E of the operation output of the blower.

(Step S36)
The control unit 20 determines the blower operation output doubling coefficient H according to the temperature of the outside air and the operation capacity of the indoor unit 53. However, the blower operation output doubling coefficient H is set to a value larger than 1. Thereafter, the control unit 20 proceeds to (Step S37).

(Step S37)
The control unit 20 determines that the heating load is high and increases the operation output from the normal operation of the blower. Therefore, the controller 20 multiplies E, which is the operation output of the blower during the normal operation, by a fan operation output doubling factor H, The value is determined as the blower air volume maximum value F. Thereafter, the control unit 20 proceeds to (Step S38).

(Step S38)
The control unit 20 sets the operation output that exceeds the operation output of the blower during normal operation, with the maximum value of the operation output of the blower as the blower airflow maximum value F. Thereafter, the control unit 20 proceeds to (Step S39).

(Step S39)
The control unit 20 determines whether or not TdSH1> TdSH2. If TdSH1> TdSH2, the control unit 20 proceeds to (Step S40), and otherwise proceeds to (Step S41).

(Step S40)
The control unit 20 decreases the operation output of the blower 6 and increases the operation output of the blower 106. Thereafter, the control unit 20 proceeds to (Step S31).

(Step S41)
The control unit 20 increases the operation output of the blower 6 and decreases the operation output of the blower 106. Thereafter, the control unit 20 proceeds to (Step S31).

  Here, for example, the liquid leveling means by the blower will be described as an example in which the heat exchanger capacity on the outdoor unit 51 side is small with respect to the refrigerant circulation amount and the liquid refrigerant is unevenly distributed on the outdoor unit 51 side. In order for the refrigerant discharge amount of the compressor 1 and the compressor 101 to be in a state where the refrigerant is diverted at a desired ratio, the heat source side heat from the refrigerant branch point 19 with respect to the refrigerant circulation amount of the compressor 1 and the compressor 101. The degree of superheat to the outlet of the exchanger 2 is made equal to the degree of superheat from the refrigerant branch point 19 to the outlet of the heat source side heat exchanger 102. Furthermore, what is necessary is just to make discharge superheat degree of the compressor 1 and the compressor 101 more than a reference value or equivalent.

  Therefore, in (Step S39), TdSH1> TdSH2 is determined, and the heat exchanger outlet superheat degree HEXSH1 of the heat source side heat exchanger 2 and the heat exchanger outlet superheat degree HEXSH2 of the heat source side heat exchanger 102 are the reference values. To be. And based on discharge superheat degree TdSH1 of the compressor 1 and discharge superheat degree TdSH2 of the compressor 101, each superheat degree is made to become a reference value. For this purpose, at least the operating output of the blower 6 is increased and the evaporator heat exchange capacity on the outdoor unit 51 side is increased, thereby increasing the degree of superheat at the outlet of the heat source side heat exchanger 2, that is, the degree of dryness. Increase the degree of discharge superheat.

  Further, by reducing the operating output of the blower 106 and reducing the evaporator heat exchange capacity on the outdoor unit 151 side, the outlet superheat degree of the heat source side heat exchanger 102, that is, the dryness is lowered, and the compressor 101 Reduce discharge superheat.

  For this reason, the superheat degree of the heat source side heat exchanger 2, that is, the dry degree, and the superheat degree of the outlet of the heat source side heat exchanger 102, that is, the dry degree can be made equal, and the liquid refrigerant is unevenly distributed on the outdoor unit 51 side. That is solved. That is, by increasing the operation output of the blower 6 or decreasing the operation output of the blower 106, the value of TdSH1 and the value of TdSH2 can be brought close to each other, the refrigerant flow rate flowing to the outdoor unit 51 side, and the outdoor unit 151 side The flowing refrigerant flow rate can be adjusted.

  Thus, liquid leveling control for selecting the maximum output of the blower of the outdoor unit is performed by determining the air conditioning load according to the outdoor temperature and the indoor unit operating capacity. As a result, it is possible to ensure the required heating capacity and perform liquid leveling control to prevent an increase in the noise of the blower of the outdoor unit when the air conditioning load is small.

  In this liquid leveling control, the refrigerant employed in the refrigeration cycle apparatus is not particularly limited. For example, carbon dioxide, a natural refrigerant such as hydrocarbon or helium, a refrigerant such as R410A, R32, R407C, R404A, HFO1234yf, or the like. Can be used.

  As described above, according to the present embodiment, an air conditioner including a plurality of outdoor units equipped with a compressor, a heat source side heat exchanger, and a blower, and an indoor unit equipped with an indoor side heat exchanger. An unbalance in the amount of refrigerant in the plurality of outdoor units from the first superheat degree of the refrigerant flowing out from the heat source side heat exchanger and the second superheat degree of the refrigerant discharged from the compressor A control unit that executes liquid leveling control by controlling the operation output of the blower when the air temperature is generated, the control unit has an outdoor temperature greater than a predetermined value, and the indoor unit When the operating capacity is less than a predetermined value, the maximum value of the operating output of the blower is maintained, and when the outdoor temperature is lower than a predetermined value, or when the outdoor temperature is higher than a predetermined value, the indoor unit When the operating capacity of the fan is equal to or greater than a predetermined value, The maximum value of the non-inverted output so as to increase. By doing in this way, the air conditioning apparatus which can suppress the noise increase of the air blower of an outdoor unit can be obtained.

  Also, during the heating operation, adjusting the output of the blower in the outdoor unit and adjusting the output of the compressor frequency, the state of the refrigerant flowing into the heat source side heat exchanger (refrigerant dryness) and the flow rate (that is, the outdoor unit It is possible to perform liquid leveling control of each indoor unit while controlling both of the flow rate of the circulating refrigerant) and preventing a decrease in the refrigerant circulation rate.

  1 compressor, 2 heat source side heat exchanger, 3 four-way valve, 4 accumulator, 5a check valve, 5b check valve, 5c check valve, 5d check valve, 6 blower, 11 gas-liquid separator, 12a solenoid valve , 12b Solenoid valve, 13a Solenoid valve, 13b Solenoid valve, 14 Throttle device, 15 Throttle device, 16 Heat exchanger between refrigerants, 17 Heat exchanger between refrigerants, 18 Refrigerant merge point, 19 Refrigerant branch point, 20 Control unit, 22 Indoor side heat exchanger, 22a Indoor side heat exchanger, 22b Indoor side heat exchanger, 23 Indoor side expansion device, 23a Indoor side expansion device, 23b Indoor side expansion device, 31 High pressure detection means, 32 Low pressure detection means, 34 compressor discharge temperature detection means, 35 heat exchanger outlet temperature detection means, 36 outside air temperature detection means, 37 compressor discharge superheat degree calculation means, 38 heat exchanger outlet superheat degree calculation means, 41 indoors Unit operating capacity calculation means, 51 outdoor unit, 52 shunt controller, 53 indoor unit, 53a indoor unit, 53b indoor unit, 101 compressor, 102 heat source side heat exchanger, 103 four-way valve, 104 accumulator, 105a check valve, 105b Check valve, 105c Check valve, 105d Check valve, 106 Blower, 131 High pressure detection means, 132 Low pressure detection means, 134 Compressor discharge temperature detection means, 135 Heat exchanger outlet temperature detection means, 136 Outside air temperature detection Means, 137 Compressor discharge heating degree computing means, 138 Heat exchanger outlet superheat degree computing means, 141 Indoor unit operating capacity computing means, 151 Outdoor unit, 201 Low pressure pipe, 202 High pressure pipe, 203 Liquid pipe, 203a Liquid pipe, 203b Liquid pipe, 204 gas pipe, 204a gas pipe, 204b gas pipe, 500 air conditioner.

An air conditioner according to the present invention is an air conditioner including a plurality of outdoor units equipped with a compressor, a heat source side heat exchanger, and a blower, and an indoor unit equipped with an indoor side heat exchanger. In the heating operation or the heating main operation, the plurality of outdoor units are obtained from a first superheat degree of the refrigerant flowing out from the heat source side heat exchanger and a second superheat degree of the refrigerant discharged from the compressor. When it is determined that a refrigerant amount imbalance has occurred, the operation output of the outdoor unit blower with the larger refrigerant amount is increased, and the operation output of the outdoor unit blower with the smaller refrigerant amount is decreased. A control unit that performs liquid leveling control, and the control unit operates the blower normally when the outdoor temperature is higher than a reference temperature and the operation capacity of the indoor unit is less than the reference capacity. Leveling within the range of the maximum operating output It is executed, and if the outdoor temperature is below the reference temperature, or when the operating capacity of the larger the indoor unit outdoor temperature is Ri by reference temperature is the reference volume or more, the blower normal during the operation of the operation output The liquid leveling control is executed by increasing the maximum value.

According to the present invention, when the outdoor temperature is greater than a predetermined value and the operation capacity of the indoor unit is less than the predetermined value, the control unit sets the blower to an operation output during normal operation and performs liquid leveling control. is executed, and if the outdoor temperature is below a predetermined value, or when the operating capacity of the outdoor temperature is greater indoor Ri by the predetermined value is the predetermined value or more, than the operating power during normal operation the blower Increase the liquid leveling control. By doing in this way, since it becomes impossible to always increase the maximum value of the operation output of an air blower, the air conditioning apparatus which can suppress the noise increase of the air blower of an outdoor unit can be obtained.

As described above, according to the present embodiment, an air conditioner including a plurality of outdoor units equipped with a compressor, a heat source side heat exchanger, and a blower, and an indoor unit equipped with an indoor side heat exchanger. An unbalance in the amount of refrigerant in the plurality of outdoor units from the first superheat degree of the refrigerant flowing out from the heat source side heat exchanger and the second superheat degree of the refrigerant discharged from the compressor A control unit that executes liquid leveling control by controlling the operation output of the blower when the air temperature is generated, the control unit has an outdoor temperature greater than a predetermined value, and the indoor unit when operating capacity of is less than the predetermined value, maintains the maximum value of the operating power of the blower, when the outdoor temperature is below a predetermined value, or the outdoor temperature is greater Ri by a predetermined value the indoor unit When the operating capacity of the fan is equal to or greater than a predetermined value, the fan is operated. The maximum value of the force so as to increase. By doing in this way, the air conditioning apparatus which can suppress the noise increase of the air blower of an outdoor unit can be obtained.

Claims (3)

A plurality of outdoor units equipped with a compressor, a heat source side heat exchanger, and a blower, and an indoor unit equipped with an indoor side heat exchanger,
In the plurality of outdoor units, the first superheat degree of the refrigerant flowing out from the heat source side heat exchanger and the second superheat degree of the refrigerant discharged from the compressor during the heating operation or the heating main operation. When it is determined that a refrigerant amount imbalance has occurred, the operation output of the outdoor unit with the larger refrigerant amount is increased, and the operation output of the outdoor unit with the smaller refrigerant amount is decreased. A control unit that performs liquid leveling control,
The controller is
When the outdoor temperature is larger than the reference temperature and the operation capacity of the indoor unit is less than the reference capacity, the liquid equalization control is performed within the range of the maximum value of the operation output during normal operation of the blower,
When the outdoor temperature is lower than the reference temperature, or when the outdoor temperature is higher than the reference temperature and the operating capacity of the indoor unit is higher than the reference capacity, the blower is increased from the maximum value of the operating output during normal operation. Air conditioner that performs liquid leveling control. The controller is
The first superheat degree is calculated from the low pressure pressure of the refrigerant on the suction side of the compressor and the temperature of the refrigerant on the outlet side of the heat source side heat exchanger,
The air conditioning apparatus according to claim 1, wherein the second degree of superheat is calculated based on the high pressure of the refrigerant on the discharge side of the compressor and the temperature of the refrigerant on the discharge side of the compressor. The air conditioner according to claim 2, wherein the control unit controls the operation of the blower so that each of the first superheat degree and each of the second superheat degrees converge on a reference value.

Images