WO2018078808A1 - Air conditioner - Google Patents

Abstract

An air conditioner (10) is provided with a refrigerant circuit (13) and a refrigerant. The refrigerant circuit (13) includes a compressor (1), a condenser (2), a pressure adjustment valve (3), and an evaporator (4). The refrigerant is R32. The pressure adjustment valve (3) includes a flow path (33) through which the refrigerant flowing from the condenser (2) is caused to flow into the evaporator (4), a pressure reference chamber (S2) which is partitioned off from the flow path (33) and which is filled with inert gas, and a valve portion (34) disposed in the flow path (33). The pressure adjustment valve (3) can adjust the flow rate of the refrigerant flowing through the flow path (33) by adjusting the valve opening degree of the valve portion (34). The valve portion (34) operates so as to increase the valve opening degree when the pressure inside the flow path (33) becomes higher than the pressure inside the pressure reference chamber (S2), and to decrease the valve opening degree when the pressure inside the flow path (33) becomes lower than the pressure inside the pressure reference chamber (S2).

Description

Air conditioner

The present invention relates to an air conditioner.

In consideration of the global environment, a refrigerant-saving air conditioner using a low GWP (Global Warming Potential) refrigerant is demanded. R32 is used as a refrigerant for realizing a refrigerant-saving air conditioner using a low GWP refrigerant. R32 is a refrigerant having a small polytropic index and easily increasing the discharge temperature from the compressor. Therefore, when R32 is used as the refrigerant, the discharge temperature of the refrigerant from the compressor is likely to increase when the condensation temperature is high due to high outside air. If the discharge temperature of the refrigerant from the compressor rises, the compressor may break down. Therefore, it is required that the discharge temperature of the refrigerant from the compressor does not rise above the set temperature so that the compressor does not break down.

Therefore, conventionally, in an air conditioner using R32 as a refrigerant, the discharge temperature of the refrigerant from the compressor is adjusted using LEV (Linear Expansion Valve: electronic expansion valve). Specifically, the microcomputer controls the valve opening degree of the LEV based on the signal from the thermistor that detects the discharge temperature of the refrigerant from the compressor, so that the discharge temperature of the refrigerant from the compressor is lower than the set temperature. It is adjusted not to rise.

An air conditioner using R32 as a refrigerant and equipped with LEV is disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-109356 (Patent Document 1).

JP 2016-109356 A

In the air conditioner described in the above publication, the response time of the discharge temperature from the refrigerant compressor to the adjustment of the valve opening of the LEV is long. Therefore, there is a problem that the discharge temperature of the refrigerant from the compressor rises higher than the set temperature without adjusting the valve opening of the LEV in time for the rise in the discharge temperature of the refrigerant from the compressor. Further, when the amount of refrigerant decreases, the response time of the discharge temperature of the refrigerant from the compressor with respect to the adjustment of the valve opening of the LEV becomes shorter. Therefore, even if the valve opening of the LEV is adjusted so that the discharge temperature of the refrigerant from the compressor becomes the set temperature, a phenomenon (hunting) in which the discharge temperature of the refrigerant from the compressor becomes a temperature above and below the set temperature. There is a problem that occurs.

This invention is made | formed in view of the said subject, The objective is suppressing the raise of the discharge temperature from the compressor of a refrigerant | coolant, and providing a refrigerant | coolant air conditioner using the low GWP refrigerant | coolant. is there.

The air conditioner of the present invention includes a refrigerant circuit and a refrigerant. The refrigerant circuit has a compressor, a condenser, a pressure regulating valve, and an evaporator. The refrigerant flows through the refrigerant circuit in the order of the compressor, the condenser, the pressure regulating valve, and the evaporator. The refrigerant is R32. The pressure regulating valve includes a flow path for flowing the refrigerant flowing from the condenser to the evaporator, a pressure reference chamber partitioned from the flow path and filled with an inert gas, and a valve portion disposed in the flow path. It is out. The pressure adjustment valve can adjust the flow rate of the refrigerant flowing through the flow path by adjusting the valve opening degree of the valve portion. The valve unit is configured to increase the valve opening when the pressure in the flow path becomes larger than the pressure in the pressure reference chamber, and to decrease the valve opening when the pressure in the flow path becomes smaller than the pressure in the pressure reference chamber. Has been.

According to the air conditioner of the present invention, the pressure in the pressure reference chamber is set to the pressure in the flow channel at the discharge temperature from the compressor of the refrigerant at the set temperature, so that the pressure in the flow channel is set in the pressure reference chamber. When the pressure becomes larger than the pressure, the valve opening degree of the valve portion is increased, and the discharge temperature of the refrigerant from the compressor can be suppressed from rising above the set temperature. Moreover, the occurrence of hunting can be suppressed by adjusting the valve opening of the valve portion before the discharge temperature of the refrigerant from the compressor rises above the set temperature. R32 is a low GWP refrigerant. Thereby, the refrigerant | coolant air conditioner using a low GWP refrigerant | coolant is realizable.

It is a figure which shows roughly the structure of the refrigerant circuit of the air conditioner in Embodiment 1 of this invention. It is sectional drawing which shows schematically the structure of the pressure regulation valve of the air conditioner in Embodiment 1 of this invention. It is sectional drawing for demonstrating operation | movement of the valve part of the air conditioner in Embodiment 1 of this invention. It is a figure which shows roughly the structure of the refrigerant circuit of the air conditioner in a comparative example. It is a figure which shows roughly the structure of the refrigerant circuit of the air conditioner in Embodiment 2 of this invention. It is a figure which shows roughly the structure of the refrigerant circuit of the air conditioner in Embodiment 3 of this invention. It is sectional drawing which shows schematically the structure of the pressure regulation valve of the modification of the air conditioner in Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
With reference to FIG. 1, the structure of the air conditioner 10 in Embodiment 1 of this invention is demonstrated. The air conditioner 10 of the present embodiment is a cooling only machine. That is, the air conditioner 10 of the present embodiment has a cooling function but does not have a heating function.

The air conditioner 10 of the present embodiment includes a compressor 1, a condenser 2, a pressure regulating valve 3, an evaporator 4, a condenser blower 5, an evaporator blower 6, pipes PI1 to PI4, It mainly has a refrigerant. The compressor 1, the condenser 2, the pressure adjustment valve 3, and the condenser blower 5 are accommodated in the outdoor unit 11. The evaporator 4 and the evaporator fan 6 are accommodated in the indoor unit 12.

The refrigerant circuit 13 includes a compressor 1, a condenser 2, a pressure adjustment valve 3, and an evaporator 4. The refrigerant circuit 13 is configured by connecting the compressor 1, the condenser 2, the pressure regulating valve 3, and the evaporator 4 via pipes PI1 to PI4. Specifically, the compressor 1 and the condenser 2 are connected to each other by a pipe PI1. The condenser 2 and the pressure regulating valve 3 are connected to each other by a pipe PI2. The pressure regulating valve 3 and the evaporator 4 are connected to each other by a pipe PI3. The evaporator 4 and the compressor 1 are connected to each other by a pipe PI4.

The refrigerant circuit 13 is configured such that the refrigerant circulates in the order of the compressor 1, the pipe PI1, the condenser 2, the pipe PI2, the pressure regulating valve 3, the pipe PI3, the evaporator 4, and the pipe PI4. That is, the refrigerant flows through the refrigerant circuit 13 in the order of the compressor 1, the condenser 2, the pressure regulating valve 3, and the evaporator 4. The refrigerant is R32. The amount of refrigerant flowing through the refrigerant circuit 13 is preferably 300 g or more and 500 g or less.

The compressor 1 is configured to compress the refrigerant. The compressor 1 is configured to compress and discharge the sucked refrigerant. The compressor 1 has a variable capacity. The compressor 1 of the present embodiment is configured to be able to variably control the rotational speed. Specifically, the compressor 1 adjusts the rotation speed of the compressor 1 by changing the drive frequency based on an instruction from a control device (not shown). Thereby, the capacity | capacitance of the compressor 1 changes. The capacity of the compressor 1 is an amount for sending out refrigerant per unit time. That is, the compressor 1 can perform high capacity operation and low capacity operation. In the high capacity operation, the operation is performed by increasing the flow rate of the refrigerant circulating in the refrigerant circuit 13 by increasing the drive frequency of the compressor 1. In the low capacity operation, the operation is performed by reducing the flow rate of the refrigerant circulating in the refrigerant circuit 13 by lowering the drive frequency of the compressor 1.

The condenser 2 is configured to condense the refrigerant compressed by the compressor 1. The condenser 2 is an air heat exchanger composed of pipes and fins. The pressure regulating valve 3 is configured to depressurize the refrigerant condensed by the condenser 2. The pressure regulating valve 3 has a function as an expansion valve. The pressure regulating valve 3 is a mechanical pressure control valve. The pressure adjustment valve 3 is configured to be able to adjust the flow rate of the refrigerant passing through the pressure adjustment valve 3. The flow rate of the refrigerant passing through the pressure regulating valve 3 is a flow rate per unit time. The evaporator 4 is configured to evaporate the refrigerant decompressed by the pressure regulating valve 3. The evaporator 4 is an air heat exchanger composed of pipes and fins.

The condenser blower 5 is configured to adjust the amount of heat exchange between the outdoor air and the refrigerant in the condenser 2. The condenser blower 5 includes a fan 5a and a motor 5b. The motor 5b may be configured to rotate the fan 5a with a variable number of rotations. The motor 5b may be configured to rotate the fan 5a at a constant rotation speed. The evaporator blower 6 is configured to adjust the amount of heat exchange between the indoor air and the refrigerant in the evaporator 4. The evaporator blower 6 includes a fan 6a and a motor 6b. The motor 6b may be configured to rotate the fan 6a in a variable number of rotations. The motor 6b may be configured to rotate the fan 6a at a constant rotation speed.

With reference to FIG. 1 and FIG. 2, the structure of the pressure regulating valve 3 in the present embodiment will be described in detail.

The pressure regulating valve 3 includes a case 31, a diaphragm 32, a flow path 33, a valve portion 34, a spring 35, and a partition member 36. The pressure adjustment valve 3 is configured to be able to adjust the flow rate of the refrigerant flowing through the flow path 33 by adjusting the valve opening degree of the valve portion 34.

A diaphragm 32 is attached to the inside of the case 31 so as to partition the inside of the case 31. The case 31 has a first chamber S1 and a second chamber S2 partitioned by a diaphragm 32.

1st chamber S1 has the flow path 33 which flows the refrigerant | coolant which flowed in from the condenser 2 to the evaporator 4. FIG. Specifically, the first chamber S1 has an inflow portion 31a and an outflow portion 31b. The inflow portion 31a is connected to the pipe PI2. The outflow part 31b is connected to the pipe PI3. The first chamber S1 is configured such that the refrigerant flowing in the refrigerant circuit flows from the pipe PI2 through the inflow portion 31a into the first chamber S1, and flows out through the outflow portion 31b to the pipe PI3. That is, as indicated by an arrow A1 in FIG. 2, the refrigerant flowing through the refrigerant circuit flows into the first chamber S1 from the inflow portion 31a and out of the outflow portion 31b. In the present embodiment, the path from the inflow portion 31a to the outflow portion 31b constitutes the refrigerant flow path 33.

The pressure in the first chamber S1 is the pressure of the refrigerant in the flow path 33. Since the pressure in the first chamber S1 is the pressure of the refrigerant flowing in from the condenser 2, it is the pressure of the high-pressure side refrigerant flowing in the refrigerant circuit 13. Therefore, the pressure regulating valve 3 is a high pressure regulating valve.

The second chamber S2 constitutes a pressure reference chamber S2. The pressure reference chamber S2 is partitioned from the flow path 33. An inert gas is sealed in the pressure reference chamber S2. The pressure reference chamber S2 is sealed with an inert gas sealed in the pressure reference chamber S2. The pressure in the pressure reference chamber S2 becomes the pressure of the activated gas. The inert gas is, for example, nitrogen or helium. Nitrogen has the advantage of low cost. Helium has the advantage of high safety. The pressure in the pressure reference chamber S2 is, for example, 3 MPa or more and 4 MPa or less.

The diaphragm 32 is caused by a differential pressure between the pressure in the first chamber S1 and the pressure in the second chamber S2, that is, the differential pressure between the pressure of the refrigerant in the flow path 33 and the pressure of the inert gas in the pressure reference chamber S2. 2 is configured to be deformable in a direction indicated by a double arrow A2 in FIG. Specifically, the diaphragm 32 is configured to be convexly curved toward the pressure reference chamber S2 when the pressure of the refrigerant in the flow path 33 is larger than the pressure of the inert gas in the pressure reference chamber S2. Has been. On the other hand, the diaphragm 32 has a planar shape when the pressure of the refrigerant in the flow path 33 is equal to or lower than the pressure of the inert gas in the pressure reference chamber S2. That is, in this case, the diaphragm 32 does not curve convexly toward the pressure reference chamber S2.

In the first chamber S1, a valve portion 34, a spring 35, and a partition member 36 are disposed. The partition member 36 is configured to partition the first chamber S1 into a first region on the inflow portion 31a side and a second region on the outflow portion 31b side. That is, the partition member 36 is disposed between the inflow portion 31a and the outflow portion 31b in the flow path 33 from the inflow portion 31a to the outflow portion 31b.

The valve part 34 has a valve body 34a and a valve seat 34b. The valve portion 34 is configured such that the valve opening degree can be adjusted by a gap between the valve body 34a and the valve seat 34b. The valve body 34a is formed in a shaft shape. One end (first end) of the valve body 34 a is connected to the diaphragm 32. The other end (second end) of the valve body 34 a is connected to the spring 35. The valve body 34a is configured to move in the direction indicated by the double arrow A3 in FIG. That is, the valve body 34 a is configured to move in the axial direction of the valve body 34 a by the deformation of the diaphragm 32. The valve body 34a has a tapered shape in which the cross-sectional area continuously decreases from one end to the other end. The valve body 34a is configured in a truncated cone shape, and is configured such that the diameter continuously decreases in the axial direction toward the valve seat 34b.

The valve seat 34 b is provided on the partition member 36. The valve seat 34b is disposed between the inflow portion 31a and the outflow portion 31b in the flow path 33 from the inflow portion 31a to the outflow portion 31b. The valve seat 34b is provided around a valve hole 37 that penetrates the valve seat 34b. When the valve body 34a moves in the axial direction of the valve body 34a by the deformation of the diaphragm 32, the valve body 34a moves away from the valve seat 34b, thereby opening the valve hole 37. Specifically, when the pressure of the refrigerant in the flow path 33 becomes larger than the pressure of the inert gas in the pressure reference chamber S2, the diaphragm 32 is curved in a convex shape toward the pressure reference chamber S2. For this reason, the valve body 34a connected to the diaphragm 32 moves to the pressure reference chamber S2 side in the axial direction of the valve body 34a. Thereby, when the other end of the valve body 34a is separated from the valve seat 34b, the valve hole 37 is exposed from the valve body 34a, so that the valve hole 37 is opened.

The valve seat 34b is configured such that each of a surface (upper surface) on the first region side of the first chamber S1 and a surface (lower surface) on the second region side of the first chamber S1 is recessed. That is, the valve seat 34b has a recess on each of the first region side and the second region side of the first chamber S1. The valve seat 34b communicates with the bottom of the recess on the first region side of the first chamber S1 and the bottom of the recess on the second region side of the first chamber S1. The bottom of the recess on the first region side of the first chamber S1 and the bottom of the recess on the second region side of the first chamber S1 constitute a valve hole 37 that communicate with each other.

Specifically, in the valve seat 34b, each of the surface on the first region side and the surface on the second region side of the first chamber S1 is configured in a mortar shape. The valve seat 34b is configured in a mortar shape so that the surface of the first chamber S1 on the first region side continuously decreases in diameter toward the second region of the first chamber S1. The surface of the valve seat 34b on the first region side of the first chamber S1 is configured in a mortar shape so that the diameter continuously decreases toward the second region of the first chamber S1.

The valve section 34 is configured to increase the valve opening when the pressure in the flow path 33 becomes larger than the pressure in the pressure reference chamber S1. That is, when the pressure in the flow path 33 becomes larger than the pressure in the pressure reference chamber S2, the valve section 34 moves to the diaphragm 32 side in the axial direction of the valve body 34a, thereby The valve opening degree is increased by increasing the gap between the valve seat 34b and the valve seat 34b. Further, the valve portion 34 is configured to decrease the valve opening when the pressure in the flow path 35 becomes smaller than the pressure in the pressure reference chamber S2. In other words, when the pressure in the flow path 35 becomes smaller than the pressure in the pressure reference chamber S2, the valve section 34 moves to the valve body 34a by moving the valve body 34a toward the spring 35 in the axial direction of the valve body 34a. The opening between the valve seat 34b and the valve seat 34b is reduced to reduce the valve opening.

The valve portion 34 is configured such that the size of the gap between the valve body 34a and the valve seat 34b continuously changes as the valve body 34a moves in the axial direction of the valve body 34a by deformation of the diaphragm 32. Has been. That is, the valve section 34 is configured to increase or decrease the valve opening degree of the valve section 34 in proportion to the amount of movement of the valve body 34a in the axial direction.

The spring 35 is connected to the other end of the valve body 34 a and the bottom of the case 31. The spring 35 is configured to urge the valve body 34a toward the bottom of the case 31 by an elastic force.

The partition member 36 is provided with pores 38. The pores 38 are provided so as to penetrate the partition member 36. The pore 38 constitutes a part of the flow path 33. Since the pores 38 are not closed by the valve body 34a and are always open, the refrigerant can always flow through the pores 38 in the first chamber S1 from the first region to the second region. In the present embodiment, the pore 38 has a function as a capillary. That is, the refrigerant is depressurized by passing through the pores 38.

Next, the flow of the refrigerant in the refrigerant circuit of the air conditioner 10 of the present embodiment will be described.
With reference to FIG. 1, the refrigerant flowing into the compressor 1 is compressed by the compressor 1 to become a high-temperature high-pressure gas refrigerant. The high-temperature high-pressure gas refrigerant discharged from the compressor 1 flows into the condenser 2 through the pipe PI1. The refrigerant flowing into the condenser 2 exchanges heat with air in the condenser 2. Specifically, in the condenser 2, the refrigerant is condensed by heat radiation into the air, and the air is heated by the refrigerant. The high-pressure liquid refrigerant condensed in the condenser 2 flows into the pressure regulating valve 3 through the pipe PI2.

The refrigerant that has flowed into the pressure regulating valve 3 is decompressed by the pressure regulating valve 3 and becomes a low-pressure gas-liquid two-phase refrigerant. The refrigerant depressurized by the pressure regulating valve 3 flows into the evaporator 4 through the pipe PI3. The refrigerant that has flowed into the evaporator 4 exchanges heat with air in the evaporator 4. Specifically, in the evaporator 4, air is cooled by a refrigerant, and the refrigerant becomes a low-pressure gas refrigerant. The refrigerant that has been depressurized in the evaporator 4 to become low-pressure gas flows into the compressor 1 through the pipe PI4. The refrigerant that has flowed into the compressor 1 is compressed again and pressurized, and then discharged from the compressor 1.

Subsequently, the operation of the pressure regulating valve 3 in the present embodiment will be described in detail with reference to FIGS.

If the pressure of the refrigerant in the flow path 33 is equal to or lower than the pressure of the inert gas in the pressure reference chamber S2, the diaphragm 32 is maintained in a flat shape, and the valve body 34a is in contact with the valve seat 34b. For this reason, the state in which the valve hole 37 is blocked by the valve body 34a is maintained. In this state, the valve portion 34 is closed.

When the pressure of the refrigerant in the flow path 33 becomes higher than the pressure of the inert gas in the pressure reference chamber S2, the diaphragm 32 is deformed to be convex toward the pressure reference chamber S2. Due to the deformation of the diaphragm 32, the valve element 34a moves toward the pressure reference chamber S2 in the axial direction of the valve element 34a. For this reason, the valve body 34a leaves | separates from the valve seat 34b. In this state, the valve part 34 is opened. Further, when the valve element 34a moves to the pressure reference chamber S2 side in the axial direction of the valve element 34a due to the deformation of the diaphragm 32, the gap between the valve element 34a and the valve seat 34b increases. That is, the valve opening degree of the valve part 34 becomes large. As a result, the amount of refrigerant flowing through the pressure regulating valve 3 increases, and the amount of refrigerant flowing into the evaporator 4 also increases. For this reason, superheat degree (SH) becomes small. Therefore, the rise in the discharge temperature of the refrigerant from the compressor 1 is suppressed.

Further, the amount of axial movement of the valve element 34a is adjusted by the pressure of the refrigerant in the flow path 33, the pressure of the inert gas in the pressure reference chamber S2, and the biasing force of the spring 35 connected to the valve element 34a. Is possible. Moreover, the valve opening degree of the valve part 34 can be adjusted with the clearance gap between the valve body 34a and the valve seat 34b. Therefore, the amount of refrigerant flowing through the pressure regulating valve 3 can be adjusted by adjusting the axial movement amount of the valve body 34a and the valve opening degree of the valve portion 34.

Next, the effects of the present embodiment will be described in comparison with a comparative example. Hereinafter, unless otherwise specified, in this comparative example, the same reference numerals are given to the same components as those in the first embodiment, and description thereof will not be repeated.

With reference to FIG. 4, the air conditioner 10 of the comparative example includes the LEV (electronic expansion valve) 30, the thermistor 7, and the microcomputer 8. Is different. In the air conditioner 10 of the comparative example, the microcomputer 8 controls the valve opening degree of the LEV 30 based on the signal from the thermistor 7 that has detected the discharge temperature of the refrigerant from the compressor 1. The discharge temperature is adjusted so as not to rise above a set temperature (a temperature set so that the compressor 1 does not break down).

In the air conditioner 10 of the present embodiment, the refrigerant is R32. Since R32 is a refrigerant having a small polytropic index and easily increasing the discharge temperature from the compressor 1, when R32 is used as the refrigerant, the refrigerant compressor 1 is used when the condensation temperature is high at high outside air (high outside temperature). It becomes easy to raise the discharge temperature from.

According to the air conditioner 10 of the present embodiment, the pressure in the pressure reference chamber S2 flows at a set temperature (a temperature set so that the compressor 1 does not break down). By setting the pressure in the passage 33, the valve opening degree of the valve portion 34 can be increased when the pressure in the flow passage 33 becomes larger than the pressure in the pressure reference chamber S2. For this reason, it can suppress that the discharge temperature from the compressor 1 of a refrigerant | coolant rises from setting temperature. In addition, since the refrigerant | coolant amount which flows in into the evaporator 4 can also be increased by increasing the refrigerant | coolant amount which flows through the pressure regulation valve 3, a superheat degree can be made small. Therefore, an increase in the discharge temperature of the refrigerant from the compressor 1 can be suppressed. Moreover, the occurrence of hunting can be suppressed by adjusting the valve opening degree of the valve portion 34 before the refrigerant discharge temperature from the compressor 1 rises above the set temperature. R32 is a low GWP refrigerant. Thereby, the refrigerant | coolant air conditioner 10 using a low GWP refrigerant | coolant is realizable.

Further, in the air conditioner 10 of the comparative example, the LEV 30, the thermistor 7, and the microcomputer 8 are required to adjust the discharge temperature of the refrigerant from the compressor 1, so that the configuration of the air conditioner 10 is complicated. . Moreover, the manufacturing cost of the air conditioner 10 becomes high. On the other hand, in the air conditioner 10 of this Embodiment, since the discharge temperature from the compressor 1 of a refrigerant | coolant can be adjusted with the pressure control valve 3, the structure of the air conditioner 10 becomes simple. Moreover, the manufacturing cost of the air conditioner 10 can be reduced.

Further, in the air conditioner 10 of the present embodiment, the pressure adjustment valve 3 can adjust the flow rate of the refrigerant flowing through the flow path 33 by adjusting the valve opening degree of the valve portion 34, so that the valve portion 34 temporarily. Hunting can be suppressed as compared with a case where is simply opened and closed (ON / OFF). Moreover, the controllability of the refrigerant flow rate can be improved.

Further, in the air conditioner 10 of the present embodiment, the amount of refrigerant flowing through the refrigerant circuit 13 is 300 g or more and 500 g or less. According to METI data (data related to the estimation method for non-reported emissions in FY2003), the average amount of refrigerant refrigerant used in room air conditioners is 800 g. Therefore, in the air conditioner 10 of the present embodiment, the amount of refrigerant can be reduced to about half of 800 g, which is the average refrigerant Freon filling amount of the room air conditioner. In addition, if the amount of the refrigerant is ± 100 g of 400 g which is half of the average refrigerant Freon filling amount of the room air conditioner, the refrigerant can be saved while maintaining the cooling capacity.

In the air conditioner 10 of the comparative example, when the refrigerant amount decreases, the response time of the discharge temperature of the refrigerant from the compressor 1 to the adjustment of the valve opening degree of the LEV 30 is shortened, so that hunting may occur with respect to the set temperature. There is. On the other hand, in the air conditioner 10 of the present embodiment, the valve opening degree of the valve portion 34 is increased based on the pressure in the pressure reference chamber S2, so that hunting for the set temperature is achieved even when the refrigerant amount decreases. Can be suppressed. Therefore, controllability can be improved.

In the air conditioner 10 of the present embodiment, the compressor 1 can variably control the rotation speed. For this reason, power saving can be achieved by variably controlling the rotation speed of the compressor 1. In addition, even when the discharge temperature of the refrigerant from the compressor 1 is increased by increasing the rotation speed of the compressor 1, the valve opening degree of the valve portion 34 is increased based on the pressure in the pressure reference chamber S2. An increase in the refrigerant discharge temperature of the compressor 1 can be suppressed.

Embodiment 2. FIG.
Hereinafter, unless otherwise specified, in the second embodiment, the same reference numerals are given to the same components as those in the first embodiment, and description thereof will not be repeated.

Referring to FIG. 5, the air conditioner 10 according to the second embodiment of the present invention is different in the configuration of the pressure regulating valve 3 from the air conditioner 10 according to the first embodiment.

In the air conditioner 10 of the present embodiment, the pressure adjustment valve 3 includes a capillary 39. The capillary 39 is connected to the case 31 of the pressure regulating valve 3 and the evaporator 4. The configuration of the pressure regulating valve 3 in the case 31 is the same as that of the first embodiment. The capillary 39 is disposed between the valve portion 34 and the evaporator 4 in the refrigerant circuit 13. For this reason, the refrigerant can be decompressed by the capillary 39.

According to the present embodiment, the pressure reduction of the refrigerant can be adjusted by the capillary 39. For this reason, it becomes easy to adjust the decompression of the refrigerant.

Embodiment 3 FIG.
Hereinafter, unless otherwise specified, in the third embodiment, the same reference numerals are given to the same components as those in the first embodiment, and description thereof will not be repeated.

Referring to FIG. 6, the air conditioner 10 according to the third embodiment of the present invention is different from the air conditioner 10 according to the first embodiment in the configuration of the pressure regulating valve 3.

In the air conditioner 10 of the present embodiment, the pressure adjustment valve 3 includes a capillary 39. The capillary 39 is connected in parallel with the case 31 of the pressure regulating valve 3 in the refrigerant circuit 13. The configuration of the pressure regulating valve 3 in the case 31 is the same as that of the first embodiment. The capillary 39 is arranged in parallel with the valve portion 34 in the refrigerant circuit 13. For this reason, the refrigerant can be decompressed by the capillary 39.

According to the present embodiment, the pressure reduction of the refrigerant can be adjusted by the capillary 39. For this reason, it becomes easy to adjust the decompression of the refrigerant.

Subsequently, a modification of the air conditioner 10 according to Embodiment 3 will be described with reference to FIG. This modification is different from the first embodiment in that the pores 38 are not provided. In this modification, since the capillary 39 is arranged in parallel with the valve portion 34 in the refrigerant circuit 13, the capillary 39 always supplies the refrigerant to the refrigerant circuit 13 even if the pores 38 of the first embodiment are not provided. It can flow.

The capillary 39 is easier to adjust the decompression of the refrigerant than the pores 38 of the first embodiment. For this reason, in the modification of the air conditioner 10 of the present embodiment, the capillary 39 can easily adjust the decompression of the refrigerant.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 compressor, 2 condenser, 3 pressure regulating valve, 4 evaporator, 5 condenser fan, 6 evaporator fan, 7 thermistor, 8 microcomputer, 9 capillary, 10 air conditioner, 11 outdoor unit, 12 indoor unit, 13 refrigerant circuit, 31 case, 31a inflow part, 31b outflow part, 32 diaphragm, 33 flow path, 34a valve body, 34b valve seat, 35 spring, 36 partition member, 37 valve hole, 38 pore, 39 capillary, S1 1st 1 room, S2 2nd room (pressure reference room).

Claims (5)

A refrigerant circuit having a compressor, a condenser, a pressure regulating valve and an evaporator;
The refrigerant circuit comprises the compressor, the condenser, the pressure regulating valve, and a refrigerant that flows in the order of the evaporator,
The refrigerant is R32;
The pressure regulating valve is disposed in the flow path, a flow path for flowing the refrigerant flowing from the condenser to the evaporator, a pressure reference chamber partitioned from the flow path and filled with an inert gas. Including the valve part,
The pressure adjusting valve can adjust the flow rate of the refrigerant flowing through the flow path by adjusting the valve opening of the valve portion,
The valve portion increases the valve opening when the pressure in the flow path becomes larger than the pressure in the pressure reference chamber, and opens the valve when the pressure in the flow path becomes smaller than the pressure in the pressure reference chamber. An air conditioner configured to reduce the degree. The air conditioner according to claim 1, wherein the amount of the refrigerant flowing through the refrigerant circuit is 300 g or more and 500 g or less. The pressure regulating valve includes a capillary;
The air conditioner according to claim 1 or 2, wherein the capillary is disposed between the valve unit and the evaporator in the refrigerant circuit. The pressure regulating valve includes a capillary;
The air conditioner according to claim 1 or 2, wherein the capillary is arranged in parallel with the valve portion in the refrigerant circuit. The air conditioner according to any one of claims 1 to 4, wherein the compressor is capable of variably controlling the rotation speed.

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