KR20080024937A - Air conditioner - Google Patents

Abstract

An air conditioner is provided to prevent deterioration of cooling capacity while achieving sufficient degree of supercooling, since a refrigerant before being supercooled by air cooling is utilized as a low temperature heat source, preventing vaporization of liquid refrigerant in piping. An air conditioner(1) is capable of flowing a refrigerant compressed by a compressor(21) into a heat exchanger(25) to perform heat exchange between the refrigerant and air for heating and cooling. The heat exchanger of an outdoor unit(2) comprises a first heat exchanger(26) which serves as a condenser during cooling operation and an evaporator during heating operation, a second heat exchanger(27) which serves as an air cooling type supercooler during cooling operation and evaporator during heating operation, and a bypass line(30,36) which bypasses a part of the refrigerant flowing out from the first heat exchanger during cooling operation to an indoor unit(3), before the refrigerant flows into the second heat exchanger. The bypass line comprises a flow control valve(31), and a refrigerant type supercooler(32) supercooling the refrigerant supercooled in the second heat exchanger by using the refrigerant flowing through the bypass line. A liquid receiver is disposed between the first and second heat exchangers, wherein the bypass line is connected to the bottom side of the liquid receiver.

Description

Air Conditioner

1 is a view showing a schematic configuration of an air conditioner according to an embodiment of the present invention,

2 is a graph showing the relationship between the bypass amount, cooling capacity, and supercooling degree.

3 is a view showing a schematic configuration of an air conditioner provided with a receiver;

4 is an external view of an outdoor unit.

* Description of symbols on the main parts of the drawings *

1,61 .. Air conditioning equipment 2,62. Outdoor units

3 .. Indoor 25 .. Outdoor heat exchanger

26. First heat exchanger 27. Second heat exchanger

30,36,66 .. Bypass piping (bypass circuit)

31. Flow control valve 32. Refrigerant supercooler

63. Receiver 71. Case

74..Discharge fan 81,82..Suction opening (opening)

The present invention relates to an air conditioner having an air-cooled subcooler and a subcooler.

The air conditioner is configured to circulate the refrigerant discharged from the compressor between the outdoor heat exchanger and the indoor heat exchanger to perform cooling operation or heating operation. In the cooling operation, it is known that when the refrigerant is supercooled and supplied to the indoor unit, vaporization of the liquid refrigerant in the piping from the outdoor unit to the indoor unit is prevented, thereby improving the efficiency of the refrigeration cycle. As a means for subcooling a refrigerant | coolant, the air type supercooler which used the heat exchange with air, and the refrigerant | coolant type supercooler which used the heat exchange with a refrigerant | coolant is mentioned.

On the other hand, in the conventional air conditioner, the refrigerant condensed in the outdoor heat exchanger during the cooling operation is supplied to the air-cooled subcooler through the receiver to perform subcooling, and then subcooled again in the refrigerant subcooler (for example, a patent document). 1). The liquid refrigerant flowing out of the air-cooled subcooler is branched, decompressed in the capillary, and then supplied as a low-temperature heat source to the refrigerant-type supercooler. The remaining liquid refrigerant is supplied to the subcooler as it is a high temperature heat source. In the refrigerant type supercooler, the refrigerant decompressed as the low temperature heat source vaporizes the amount of heat equivalent to the latent heat of evaporation from the liquid refrigerant directed to the indoor unit, and the refrigerant directed to the indoor unit is supercooled. That is, the refrigerant branched as the low temperature heat source is recovered by the compressor by bypassing the indoor unit.

[Patent Document 1] Japanese Patent Laid-Open No. 2006-90563

However, if a part of the liquid refrigerant after passing through the air-cooled subcooler is branched to generate a low temperature heat source, the pressure of the liquid refrigerant (refrigerant supplied to the room) is lowered, and as a result, the degree of subcooling obtained from the air-cooled subcooler Inflow to the refrigerant type supercooler in a degraded state. Therefore, it was difficult to obtain sufficient subcooling degree.

In order to increase the supercooling degree in the refrigerant type supercooler, the amount of the branching refrigerant is increased as the low temperature heat source. However, when the amount of the branching refrigerant increases, the pressure of the liquid refrigerant (the refrigerant supplied to the room) is further lowered. Will be lowered. As described above, in the conventional air conditioner, there is a problem that the cooling capacity is lowered by increasing the supercooling degree.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an air conditioner capable of obtaining a sufficient degree of supercooling.

The invention according to claim 1 of the present invention for achieving the above object is an air conditioner for heating or cooling by introducing a refrigerant compressed by a compressor into a heat exchanger to heat exchange with air, wherein the heat exchanger of the outdoor unit during the cooling operation And a second heat exchanger which becomes an evaporator in a heating operation and a second heat exchanger which becomes an evaporator in a heating operation and an evaporator in a heating operation in a cooling operation, and is discharged from the first heat exchanger in an cooling operation. A bypass circuit for branching a portion of the refrigerant to the second heat exchanger and bypassing it to the indoor unit is provided, and the second circuit is exchanged using the flow regulating valve and the refrigerant flowing through the bypass circuit in the bypass circuit. It is characterized by providing a refrigerant type supercooler for further subcooling the refrigerant supercooled in the It was the air conditioner.

In the air conditioner, a part of the refrigerant condensed in the first heat exchanger flows into the refrigerant type supercooler without passing through the air cooling subcooler during the cooling operation. When the refrigerant is a low temperature heat source and the air cooled by the second heat exchanger is a high temperature heat source, the refrigerant directed to the outdoor unit through the refrigerant type supercooler is further cooled.

Preferred embodiments for carrying out the invention will be described in detail with reference to the drawings. Hereinafter, the same code | symbol is attached | subjected to the same component in each embodiment. In addition, the description which overlaps in each embodiment is abbreviate | omitted.

(First embodiment)

As shown in FIG. 1, in the air conditioner 1, an outdoor unit 2 and an indoor unit 3 are connected through a liquid pipe 4 and a gas pipe 5. In the indoor unit 3, two indoor unit 10 are connected in parallel. Each indoor unit 10 has an indoor heat exchanger 11 and an expansion valve 12 connected in series, and is capable of delivering air to the outer circumference of the indoor heat exchanger 11 with a fan 13. In FIG. 1, the indoor unit 3 is composed of two indoor unit 10, but the number of indoor unit 3 may be one or three or more.

The outdoor unit 2 includes a compressor 21 for compressing a gas refrigerant, and a discharge pipe 22 connected to the discharge port of the compressor 21 is connected to the first port 23a of the four-way valve 23. The four-way valve 23 is provided with four ports, and when the 1st port 23a and the 2nd port 23b are connected, the 3rd port 23c and the 4th port 23d are connected. In addition, when the first port 23a and the third port 23c are connected, the second port 23b and the fourth port 23d are connected. The second port 23b of the four-way valve 23 is connected to an inlet and outlet of the outdoor heat exchanger 25 through a pipe 24.

The outdoor heat exchanger 25 includes a first heat exchanger 26 to which a pipe 24 is connected, and a second heat exchanger 27 connected to the first heat exchanger 26 through a branch pipe 28. The air is sent out from the blower fan 29 to the outer periphery of each of the heat exchangers 26 and 27. The first and second heat exchangers 26 and 27 together function as evaporators in the heating operation. In the cooling operation, the first heat exchanger 26 functions as a condenser, and the second heat exchanger 27 functions as an air-cooled supercooler. To this end, the first heat exchanger 26 has a capacity sufficient to bring the gas refrigerant into a substantially saturated liquid state during the cooling operation.

The distribution pipe 28 is a bypass pipe 30 for branching part of the liquid refrigerant from the inlet and outlet of the first heat exchanger 26 to the inlet and outlet of the second heat exchanger 27 during the cooling operation. The bypass pipe 30 is connected to the refrigerant type supercooler 32 after the flow rate control valve 31 is provided. The flow rate regulating valve 31 is a means for adjusting the amount of refrigerant bypassed and generating a low temperature heat source for use in the refrigerant type supercooler 32. The opening and closing degree control is performed by the controller 33.

The refrigerant supercooler 32 has a double pipe structure, and the bypass pipe 30 of the branch pipe 28 is connected to the inlet 35a of the inner flow path 35. The outlet 35b of the inner flow path 35 is connected to the accumulator 40 through the bypass pipe 36 (bypass circuit). In addition, the pipe 42 connected to one inlet and outlet 41a of the outer side flow passage 41 is connected to the inlet and outlet of the second heat exchanger 27 after the expansion valve 43 for heating is provided. A liquid pipe 44 is connected to the other inflow outlet 41b of the outer flow passage 41. The liquid pipe 44 is provided with a thermometer 45 for measuring the temperature of the coolant in the vicinity of the inlet and outlet 41b and is connected to the liquid pipe 4 through the valve 46.

In addition, the gas pipe 5 is connected to the gas pipe 48 through the valve 47. The gas pipe 48 is connected to the third port 23c of the four-way valve 23. A pipe 49 is connected to the fourth port 23d of the four-way valve 23. The pipe 49 is connected to the accumulator 40 after joining the bypass pipe 36 extending from the refrigerant subcooler 32 on the way. The suction pipe 50 extends from the accumulator 40 and is connected to the suction port of the compressor 21.

Next, operation | movement of the air conditioner 1 mentioned above is demonstrated.

In the cooling operation, the first port 23a and the second port 23b of the four-way valve 23 are connected, and the third port 233c and the fourth port 23d are connected. In addition, the flow regulating valve 31 is slightly opened. The high temperature and high pressure gas refrigerant discharged from the compressor 21 is supplied to the first heat exchanger 26 of the outdoor heat exchanger 25 through the four-way valve 23. The first heat exchanger 26 functions as a condenser so that the gas refrigerant exchanges heat with the air flowing in the blower fan 29 to form a substantially saturated liquid refrigerant. This liquid refrigerant flows out into the branch pipe 28 and a part of the liquid refrigerant is supplied to the refrigerant type supercooler 32. At this time, by passing through the slightly open flow control valve 31, it is adiabatic and expands into a low temperature liquid refrigerant. This low temperature liquid refrigerant flows into the inner flow path 35 of the refrigerant type supercooler 32 as a low temperature heat source. On the other hand, the liquid refrigerant flowing into the second heat exchanger 27 from the branch pipe 28 is supercooled by the blowing by the blowing fan 29. This liquid refrigerant flows into the one inflow outlet 41a of the outer flow path 41 of the refrigerant type supercooler 32 through the pipe 42. This liquid refrigerant becomes a high temperature heat source having a large amount of heat relative to the low temperature heat source.

In the refrigerant type supercooler 32, heat exchange is performed between the liquid refrigerant flowing outside and the low temperature refrigerant flowing inside. Specifically, the refrigerant in the inner passage 35 serving as the low temperature heat source vaporizes heat from the liquid refrigerant in the outer passage 41 serving as the high temperature heat source. For this reason, the liquid refrigerant of the outer side flow path 41 is subcooled only by the latent evaporation heat required for the refrigerant | coolant of the inner side flow path 35 to evaporate. The supercooled liquid refrigerant is supplied to the indoor unit 3 through the liquid pipe 44.

In the indoor unit 3, heat exchange is performed in the indoor heat exchanger 11, and the heat amount corresponding to the latent heat of evaporation is vaporized from the air. This cools the room using the cooled air. The gas refrigerant flowing out from the indoor heat exchanger 11 is recovered to the outdoor unit 2 through the gas pipe 5. In the outdoor unit (2), the gas flows from the gas pipe (48) to the pipe (49) through the third port (23c) and the third port (23d) of the four-way valve 23, and flows from the refrigerant type supercooler (32). After joining the refrigerant, it is introduced into the accumulator 40. Then, gas refrigerant is sucked into the compressor 21 from the accumulator 40.

Here, the control apparatus 33 adjusts the opening / closing degree of the flow regulating valve 31, monitoring the temperature of the thermometer 45. FIG. As shown in FIG. 2, the subcooling degree in the refrigerant type supercooler 32 increases the bypass amount, that is, the opening and closing degree of the flow regulating valve 31 to allow the refrigerant to pass through the inside of the refrigerant type subcooler 32. As the amount of is increased, the capacity of the refrigerant subcooler 32 is increased. Since the supercooling degree of the air-cooled subcooler is approximately constant without depending on the change in the bypass amount, the total cooling degree of the air-cooled subcooler and the refrigerant subcooler 32 increases. By increasing the bypass amount, the amount of refrigerant supplied to the indoor unit 3 decreases, but the total supercooling degree increases, so that the difference in enthalpy between the inlet and the outlet of the indoor heat exchanger 11 can be increased, resulting in a decrease in cooling capacity. Can be suppressed. For example, if the supercooling degree of the liquid refrigerant flowing out from the refrigerant type supercooler 32 is 20K, the liquid refrigerant does not vaporize along the way even if the liquid pipe 4 is long or there are a large number of indoor unit 10. But also enough cooling capacity can be obtained.

On the other hand, during the heating operation, the flow rate regulating valve 31 is closed so that the refrigerant type supercooler 32 is not used. In addition, both the first and second heat exchangers 26 and 27 are used as evaporators. By using the second heat exchanger 27 also as an evaporator, the heating capacity can be improved.

In this embodiment, since the air-cooled subcooler and the refrigerant subcooler 32 are installed in substantially parallel, the air before the subcooling in the air-cooled subcooler is led to the refrigerant subcooler 32 as the low temperature heat source, so that the air temperature fluctuates. In this case, the degree of supercooling can be stabilized. When two types of supercoolers are installed in series as in the prior art, part of the air-cooled liquid refrigerant is used as a low temperature heat source, so the pressure of the liquid refrigerant decreases and the supercooling degree of the inlet of the refrigerant type supercooler 32 decreases. Although it was not possible to increase the supercooling degree through the refrigerant type supercooler 32, in this embodiment, since the refrigerant before air cooling is used as the low temperature heat source, the capability of the refrigerant type supercooler 32 can be increased. Although the amount of the refrigerant circulated to the indoor unit 3 by the bypass decreases, the capacity of the refrigerant type supercooler 32 increases, so that the cooling capacity can be prevented from being greatly reduced. For this reason, when the liquid piping 4 and the gas piping 5 are long pipe | tubes, or when several indoor unit 10 is connected, the capacity | capacitance deterioration and the capability deviation of the indoor unit 10 can be prevented. .

(2nd Embodiment)

As shown in FIG. 3, the air conditioner 61 includes an outdoor heat exchanger 25 having a first heat exchanger 26 and a second heat exchanger 27, and these heat exchangers 26 and 27 are provided. It is connected via the receiver 63. In the receiver 63, the liquid refrigerant is supplied to the refrigerant type supercooler 32. More specifically, the pipe 64 connected to the inflow outlet (outlet during the cooling operation) of the first heat exchanger 26 is inserted into the receiver 63. A pipe 65 connected to an inlet outlet (inlet port during cooling operation) of the second heat exchanger 27 is also inserted into the receiver 63. At the bottom of the receiver 63, the bypass pipe 66, which forms a bypass circuit, is extended so that the inlet of the inner flow path 35 of the refrigerant subcooler 32 is provided after the flow regulating valve 31 is provided. It is connected to 35a. The rest of the configuration is the same as in the first embodiment.

Next, the operation of the air conditioner 61 will be described.

In the cooling operation, the gas refrigerant discharged from the compressor 21 flows into the first heat exchanger 26. The first heat exchanger 26 functions as a condenser to form a high pressure liquid refrigerant by heat exchange. This liquid refrigerant flows into the receiver 63 from the pipe 64. The pressure of the liquid refrigerant decreases by staying in the receiver 63. Since the bypass pipe 66 is connected to the bottom of the receiver 63 and the flow regulating valve 31 is slightly open, only the refrigerant very close to the saturated liquid is taken out and the flow regulating valve 31 is removed. After the pressure is reduced, it is supplied to the inner passage 35 of the refrigerant type supercooler 32 as a low temperature heat source.

In the receiver 63, a liquid refrigerant is also supplied to the second heat exchanger 27. The liquid refrigerant supplied to the second heat exchanger 27 (air-cooled subcooler) is subcooled by air cooling and further cooled by the refrigerant-type subcooler 32 to be supplied to the indoor unit 3.

On the other hand, the liquid refrigerant taken out for the low temperature heat source is sucked into the compressor 21 by bypassing the indoor unit 3. The opening / closing degree of the flow regulating valve 31 is adjusted so that the subcooling degree is 20K, for example, by measuring the subcooling degree as described above.

During the heating operation, the flow regulating valve 31 is closed. In addition to the first heat exchanger 26, the second heat exchanger 27 functions as an evaporator, thereby exhibiting high heating capacity.

According to the present embodiment, a part of the liquid refrigerant is branched from the receiver 63 before being passed through the air-cooled subcooler to be used as the low-temperature heat source of the refrigerant subcooler 32, so that the same effect as in the first embodiment can be obtained. Can be. In particular, since the receiver 63 is used to branch off the refrigerant for low temperature heat source, the degree of drying of the refrigerant to be bypassed can be made very small. For this reason, the difference in enthalpy between the inlet 35a and the outlet 35b on the low temperature heat source side of the refrigerant type supercooler 32 can be increased. Therefore, even when the same amount of refrigerant is bypassed, not only can the supercooling degree be increased, but also the supercooling degree can be increased while suppressing the decrease in the cooling capacity.

In addition, since the functions of the condenser (the first heat exchanger 26) and the air-cooled subcooler (the second heat exchanger 27) are separated from the receiver 63, the capacity of the air-cooled supercooler is stabilized even when the operating conditions change. can do.

(Third embodiment)

4 shows the exterior of the outdoor unit 2 of the air conditioner 1. The outdoor unit 2 has each component accommodated in the substantially rectangular parallelepiped casing 71. The discharge port 73 is provided in the ceiling name 72 of the case 71, and the discharge fan 74 (blowing fan) is arrange | positioned here. On the sides of the case 71, that is, the front face 75, the two side faces 76 and 77, and the rear face 78, each of the inlets 81 and 82 (the side face 77 and the back face 78) as an opening for blowing air. The suction port of the (not shown) is formed. Inside the front surface 75, a second heat exchanger 27 serving as an air-cooled subcooler is disposed in contact with the suction port. The first heat exchanger 26 is disposed in contact with the inlet 82 of each of the two side surfaces 76 and 77 and the rear surface 78, and is substantially U-shaped when viewed in plan view, for example, as indicated by the broken line. It is. Each side 75 to 78 may be a suction port. In addition, a suction port may be formed in a portion of the panel forming each surface.

When the air conditioner 1 is operated, the upper discharge fan 74 rotates. Air is sucked from the four suction ports 81 and 82 provided on the four sides 75 to 78 on the side, and is discharged from the upper discharge port 73 through the first and second heat exchangers 26 and 27. At this time, heat exchange is performed between the refrigerant flowing in the first and second heat exchangers 26 and 27.

In the outdoor unit 2, when viewed in a plan view from the rotation axis direction of the discharge fan 74, the first and second heat exchangers 26 and 27 are arranged to surround the discharge fan 74, so that the fan efficiency is improved. Therefore, all the air flow rates can be increased by the amount of air flow through the second heat exchanger 27 without reducing the air flow rate flowing through the first heat exchanger 26. Since the air flowing through each of the first heat exchanger 26 and the second heat exchanger 27 is individually secured, each air does not affect the characteristics of the mutual heat exchanger, and thus stable performance can be obtained. In this regard, during the cooling operation, a large subcooling degree can be obtained while securing the condensation capacity, and a decrease in the cooling capacity can be suppressed even in a long pipe. In addition, it is possible to improve the heating capacity according to the increase in the air flow rate during heating operation.

Here, the outdoor unit 62 of the air conditioner 61 according to the second embodiment can also have the same shape. The same effects and effects as described above can be obtained.

In addition, this invention is not limited to each said embodiment, It can apply widely. For example, the thermometer 45 is provided at the outlet 35b side of the inner passage 35 of the refrigerant type supercooler 32, and the supercooling degree of the liquid refrigerant supplied to the indoor unit 3 is estimated from the temperature of the refrigerant flowing out. The opening and closing degree of the flow regulating valve 31 can also be controlled.

In FIG. 4, the second heat exchanger 27 may be disposed over two or more surfaces. The first heat exchanger 26 may be disposed only on one side, or may be disposed on two or four sides.

According to the present invention, since the refrigerant before subcooling by air cooling is used as a low temperature heat source, the refrigerant after subcooling in air cooling is further subcooled, thereby preventing the pressure drop of the refrigerant after subcooling by air cooling, thereby improving the performance of the refrigerant type supercooler. Can be improved. Therefore, not only the supercooling degree of the refrigerant directed to the outdoor unit can be sufficiently secured, but also the vaporization of the liquid refrigerant in the pipe can be prevented. In addition, when a plurality of indoor units is provided, the generation of capability differences between the indoor units is prevented.

Claims (3)

An air conditioner for heating or cooling by introducing a refrigerant compressed by a compressor into a heat exchanger and heat-exchanging with air, The heat exchanger of the outdoor unit includes a first heat exchanger that becomes a condenser in the cooling operation and an evaporator in the heating operation, and a second heat exchanger that becomes an air-cooled supercooler in the cooling operation and an evaporator in the heating operation. A bypass circuit for branching a portion of the refrigerant flowing out of the first heat exchanger before it flows into the second heat exchanger and bypassing the indoor unit is provided, and the flow rate control valve and the bypass circuit flow in the bypass circuit. And a refrigerant type supercooler for further subcooling the refrigerant subcooled in the second heat exchanger by using the refrigerant. The method of claim 1, A receiver is provided between the first heat exchanger and the second heat exchanger, and the bypass circuit is connected to the bottom of the receiver. The method according to claim 1 or 2, The outdoor unit includes a case of a rectangular parallelepiped in which a blowing fan is installed, The first heat exchanger and the second heat exchanger are disposed in the case so as to surround the fan when viewed in the rotational axis direction of the fan, and air is provided on a side of the case which contacts the first heat exchanger and the second heat exchanger. An air conditioner, characterized in that an opening is formed therethrough.

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