JP5300657B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and is particularly suitable for an air conditioner including a four-way switching valve that switches between heating operation and cooling operation.

  In an air conditioner that forms a refrigeration cycle by connecting a compressor, outdoor heat exchanger, expansion valve, indoor heat exchanger, etc. with refrigerant piping, heating operation and cooling are performed by switching the refrigerant flow path using a four-way switching valve. It is known to switch between driving.

  There exists a thing shown by Unexamined-Japanese-Patent No. 2002-22315 (patent document 1) as a conventional air conditioner. Patent Document 1 includes an air conditioner (prior art 1) shown in FIG. 6 of Patent Document 1, an air conditioner (prior art 2) shown in FIG. 7 of Patent Document 1, and FIGS. A four-way switching valve (prior art 3) shown in FIG.

  The air conditioner of prior art 1 includes a compressor that compresses refrigerant gas, and a four-way switching valve that changes the circulation direction of the refrigerant gas in order to cool or heat the room. This four-way switching valve is provided with a high-pressure side conduit, two conduits (outdoor conduit and indoor conduit), one low-pressure conduit, and a valve body. The high pressure side conduit is connected to the discharge port of the compressor, the outdoor side conduit is connected to the outdoor heat exchanger, the indoor side conduit is connected to the indoor heat exchanger, and the low pressure side conduit is connected to the suction port of the compressor. Yes. Here, the high-pressure side conduit is connected to face the upper surface of the valve body, and the high-pressure side conduit and the low-temperature side conduit are arranged in a straight line. An expansion valve that adjusts the pressure of the refrigerant gas flowing between the heat exchangers is disposed between the indoor heat exchanger and the outdoor heat exchanger.

  When the valve body of the four-way switching valve is in the heating operation state, the high-temperature and high-pressure refrigerant output from the compressor enters the indoor heat exchanger from the four-way switching valve through the indoor side conduit, dissipates heat, and After the heat exchange and the temperature becomes low, it passes through the expansion valve and enters the outdoor heat exchanger. The low-temperature refrigerant gas that has flowed into the outdoor heat exchanger absorbs heat from the outside air and circulates back from the indoor side conduit 4 to the compressor via the low pressure side conduit 5. As a result, the room is heated.

  When the valve body of the four-way switching valve is switched to the cooling operation state, the high-temperature and high-pressure refrigerant from the compressor enters the outdoor heat exchanger through the outdoor conduit from the four-way switching valve, dissipates heat, and exchanges heat with the outside air. Then, after passing through the expansion valve and exchanging heat with the indoor air by the indoor heat exchanger and absorbing the heat, it returns to the compressor from the indoor conduit through the low pressure conduit and circulates. As a result, the room is cooled.

  Further, in the air conditioner of the prior art 2, the configuration of the four-way selector valve of the prior art 1 is not greatly changed, the heating efficiency is emphasized, the position of the high pressure side conduit is changed, and the high pressure side conduit is opposed to the indoor side conduit. They are arranged so as to be substantially straight.

  Furthermore, in the four-way selector valve of the prior art 3, the high-pressure side conduit is formed in two branches, and the two high-pressure conduits formed in the two branches are disposed in the valve casing so as to face the indoor conduit and the outdoor conduit, respectively. In addition, the valve body is provided with means for always shielding either one of the two high-pressure conduits.

JP 2002-22315 A

  However, in the air conditioner of the prior art 1 described above, the high pressure side conduit is connected to face the center of the upper surface of the valve body, and the high pressure side conduit and the low temperature side conduit are arranged in a straight line. Therefore, the high-temperature refrigerant flowing in from the high-pressure side conduit collides with the valve body arranged just above the low-temperature side conduit, and is bent greatly. As a result, a pressure loss is caused, and a high-temperature refrigerant becomes a collision flow that flows toward the valve casing. Therefore, heat transfer from the high-temperature refrigerant to the valve casing around the valve body is promoted.

  Moreover, in the air conditioner of the above-described prior art 2, since the high-pressure side conduit is disposed so as to be substantially straight in opposition to the indoor-side conduit, the high-temperature refrigerant flowing from the high-pressure side conduit during heating is linear. To flow out of the indoor conduit. Thereby, the pressure loss on the high pressure side can be reduced. However, in the air conditioner of the prior art 2, since heat transfer from the high-temperature refrigerant to the low-temperature refrigerant through the valve seat is not taken into consideration, there is a possibility that the heating efficiency is reduced. That is, in the air conditioner of the prior art 2, the high-pressure side conduit is arranged so as to be substantially straight so as to face the indoor side conduit, so that the pressure loss is reduced as described above so that the high-temperature refrigerant has. The heat transfer through the valve seat is increased because the energy present is maintained high. As a result, the heating efficiency may be reduced.

  Furthermore, the above-described four-way selector valve of Prior Art 3 has a problem that the structure becomes complicated and expensive.

  The objective of this invention is providing the air conditioner which can improve the efficiency of a refrigerating cycle, setting it as a simple and cheap four-way switching valve.

In order to achieve the above-mentioned object, in the present invention, a compressor, a four-way switching valve, an indoor heat exchanger, a pressure reducing means, and an outdoor heat exchanger are connected by a refrigerant pipe and filled with a refrigerant. A refrigeration cycle and a control device for switching the four-way switching valve to perform a cooling / heating operation. The four-way switching valve has a cylindrical valve casing closed at both ends, and extends in the cylinder axial direction in the valve casing. A metal valve seat having a flat seat surface, a valve body arranged to be movable in the cylinder axis direction on the seat surface of the valve seat, and a copper connected to the valve casing The valve seat is provided with an outdoor communication passage, a low-pressure communication passage, and an indoor communication passage that are sequentially opened in the cylinder axis direction and open on the seat surface. The outer space of the valve casing is connected to the discharge side of the compressor. A low pressure side conduit which communicates with the outdoor conduit, and a suction side of the compressor and the low pressure side communication passage and the high pressure side conduit, and said outdoor heat exchanger and said chamber outer communicating path communicating to said indoor side The valve body includes an indoor side conduit communicating with the communication path and the indoor heat exchanger, and the valve body communicates the high pressure side conduit and the indoor side conduit during heating to flow a high-temperature refrigerant and the low pressure side conduit. flowing cryogen communicating with said chamber outer conduit, low temperature communicates with the indoor-side conduit and the low-pressure side conduit with communicating with said chamber outer conduit and the high-pressure side conduit during the cooling flow temperature refrigerant The high-pressure side conduit is arranged so as to face the indoor-side conduit and be substantially straight, and the indoor-side conduit, the low-pressure-side conduit, and the outdoor-side conduit are connected to the indoor side. The communication path, the outdoor communication path, and the low pressure side In an air conditioner which is welded to the wall of the passage, manganese brass as the amount of transfer of heat during the heating through the valve seat to cryogen from the high-temperature refrigerant as the valve seat is reduced 1-4% with use of the valve seat of the added material, the amount of increase in the heating capacity by reducing the amount of heat transfer during the heating is greater than the amount of increase in the compressor input by reducing the amount of heat transfer during the heating as the compressor It is in the configuration using a compressor.

  A more preferable specific configuration example of the present invention is as follows.

    (1) The indoor conduit, the low pressure conduit, and the outdoor conduit are brazed to the wall surfaces of the indoor communication passage, the outdoor communication passage, and the low pressure communication passage, respectively.

  ADVANTAGE OF THE INVENTION According to this invention, the air conditioner which can improve heating efficiency can be provided, making it a simple and cheap four-way switching valve.

It is a figure which shows the structure at the time of the heating operation of the air conditioner of 1st Embodiment of this invention. It is a figure which shows the structure at the time of the cooling operation of the air conditioner of FIG. It is sectional drawing perpendicular | vertical to the cylinder-axis direction of the four-way switching valve of FIG. It is a cross-sectional perspective view explaining the flow of the refrigerant | coolant of the four-way selector valve of FIG. It is a figure which compares and shows the Mollier diagram at the time of the heating of the air conditioner provided with the conventional four-way selector valve, and the air conditioner of this embodiment. It is a schematic diagram explaining the amount of heat transfer at the time of heating of the conventional four-way selector valve. It is a figure which contrasts and shows the Mollier diagram at the time of the cooling of the air conditioner provided with the conventional four-way switching valve and the air conditioner of this embodiment.

  Hereinafter, an air conditioner according to an embodiment of the present invention will be described with reference to the drawings.

  First, the overall configuration of the air conditioner 10 of the present embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing a configuration during heating operation of the air conditioner according to the first embodiment of the present invention, FIG. 2 is a diagram showing a configuration during cooling operation of the air conditioner of FIG. 1, and FIG. FIG. 4 is a cross-sectional perspective view illustrating the flow of refrigerant in the four-way switching valve of FIG. 1. 3 and 4, the connecting plate 38 and the piston plate 40 are omitted.

  As shown in FIGS. 1 and 2, the air conditioner 10 includes a refrigeration cycle, a control device 50, and the like.

  The refrigeration cycle is formed by connecting a compressor 12, a four-way switching valve 10, an outdoor heat exchanger 14, an expansion valve 16 that is a decompression unit, and an indoor heat exchanger 18 through a refrigerant pipe 20. . A refrigerant is sealed in the refrigeration cycle. In the refrigeration cycle, during the heating shown in FIG. 1, the refrigerant flows in the order of the compressor 12, the four-way switching valve 30, the indoor heat exchanger 18, the expansion valve 16, the outdoor heat exchanger 14, the four-way switching valve 30, and the compressor 12. A refrigerant is formed in the order of the compressor 12, the four-way switching valve 30, the outdoor heat exchanger 14, the expansion valve 16, the indoor heat exchanger 18, the four-way switching valve 30, and the compressor 12 during the cooling shown in FIG. It constitutes a flowing cooling cycle. Switching between the heating cycle and the cooling cycle is performed by a switching operation of the four-way switching valve 30. The switching operation of the four-way switching valve 30 is performed under the control of the control device 50.

  The control device 50 controls the rotational speed of the compressor 12, the opening degree of the expansion valve 16, the movement (switching) of the valve body 36 of the four-way switching valve 30 and the like based on the detection signal of the temperature sensor, the command signal from the remote controller, and the like. It is something to control.

  The four-way switching valve 30 includes a high-pressure side conduit 22 that communicates with the discharge port of the compressor 12, a low-pressure side conduit 24 that communicates with the suction port of the compressor 12, an indoor side conduit 26 that communicates with the indoor heat exchanger 18, and outdoor heat exchange. Outdoor conduits 28 communicating with the vessel 14 are connected to the valve casing 32, respectively. These conduits 22, 24, 26, 28 are made of copper pipes and are welded to the valve casing 32 by brazing. The high-pressure side conduit 22, the low-pressure side conduit 24, the indoor side conduit 26, and the outdoor side conduit 28 are disposed on opposite sides of the valve casing 32 in the circumferential direction. The indoor side conduit 26, the low pressure side conduit 24, and the outdoor side conduit 28 are arranged in this order in the cylinder axis direction. The high-pressure side conduit 22 is arranged so as to face the indoor-side conduit 26 and be substantially straight.

  The four-way selector valve 30 has a cylindrical metal valve casing 32 whose both ends are closed, and a metal member having a planar seat surface 34a which is disposed in the valve casing 32 so as to extend in the cylinder axis direction. The valve seat 34, the resin valve body 36 provided on the seat surface 34a of the valve seat 34 so as to be slidable along the cylinder axis direction, and the metal piston provided movably on both sides in the valve casing 32 The plate 40a, 40b and the metal connection plate 38 that connects the piston plates 40a, 40b and the valve body 36 are provided.

  The valve casing 32 is formed of a brass member including a cylindrical tube wall portion 32a and disk-shaped end wall portions 32b that close both ends of the tube wall portion 32a.

The valve seat 34 is made of a material obtained by adding 1 to 4% of manganese to brass. As a result, it is possible to reduce the thermal conductivity while allowing the valve seat 34 and the conduits 24, 26, and 28 to be brazed. In the valve seat 34, a chamber communicating with the indoor conduit 26, a communication passage 34 b communicating with the indoor conduit 26, a low pressure communication passage 34 c communicating with the low pressure conduit 24 , and a chamber communicating with the outdoor conduit 28. An outer communication path 34d is formed. The indoor side communication path 34b, the low pressure side communication path 34c, and the outdoor side communication path 34d are each opened in the seat surface 34a.

The distal ends of the indoor side conduit 26, the low pressure side conduit 24, and the outdoor side conduit 28 are inserted into the indoor side communication passage 34b, the low pressure side communication passage 34c, and the outdoor side communication passage 34d, and brazed to the wall surfaces of the respective passages. The welded valve body 36 has a sliding surface 36e that slides on the seat surface 34a and a recess 36a formed in the sliding surface 36e. An outer wall surface 36b opposite to the sliding surface 36e is formed in a curved surface (mountain shape) corresponding to the recess 36a. The outer wall surface 36 b is formed with a space from the cylindrical wall portion 32 a of the valve casing 32.

  The central portion of the connecting plate 38 is fitted and fixed to the edge portion 36c of the valve body 36. Both ends of the connecting plate 38 are fixed to the piston plates 40a and 40b. The connecting plate 38 is for connecting the valve body 36 and the piston plates 40a and 40b. On both the left and right sides of the connecting plate 38, a communication hole 38a that connects the high-pressure side conduit 22 and the indoor side conduit 26 during heating, and a communication hole 38b that connects the high-pressure side conduit 22 and the outdoor side conduit 28 during cooling are formed. Has been.

  The piston plate 40 has the same outer peripheral shape as the inner peripheral surface of the cylindrical wall portion 32 a of the valve casing 32, and pressure adjustment spaces 42 a and 42 b are formed at both ends of the valve casing 32.

By adjusting the pressure in the pressure adjusting spaces 42a and 42b, the valve element 36 is slid and moved along the cylinder axis direction on the seat surface 34a of the valve seat 34. For example, by the pressure of the pressure regulation space 42 pressure a> pressure regulation space 42b, the piston plate 40a is pushed to the left side, the piston plate 40b, 40a, connecting plate 38 and the valve body 36 in Figure 1 together As shown, it is moved to the left and moved until the piston plate 40a abuts against one end of the valve seat 34. On the contrary, by setting the pressure of the pressure adjustment space 42a <the pressure of the pressure adjustment space 42b, the piston plate 40b is pushed to the right side, and the piston plates 40b and 40a, the connecting plate 38, and the valve body 36 are integrated into FIG. As shown, it is moved to the right and moved until the piston plate 40b contacts the other end of the valve seat 34.

  In the state where the valve body 36 is moved in the cylinder axis direction on the seat surface 34a to be one moving end (the state moved to the left side shown in FIG. 1), the outdoor conduit 28 and the low-pressure side conduit 24 are valved. The refrigerant is caused to flow through the body depression 36 a to flow the refrigerant from the outdoor conduit 28 to the low pressure side conduit 24 via the valve body depression 36 a, and the refrigerant is straightened from the high pressure side conduit 22 to the indoor side conduit 26. Let it flow.

  Further, the valve body 36 is moved in the cylinder axis direction on the seat surface 34a to be the other moving end (a state moved to the right side shown in FIG. 2). Is communicated through the valve body recess 36a to allow the refrigerant to flow from the indoor side conduit 26 to the low pressure side conduit 24 through the recess 36a of the valve body 36, and from the high pressure side conduit 22 to the outer wall surface 36b of the valve body 36. The refrigerant is caused to flow to the outdoor conduit 28 through a space facing the outside.

  The four-way switching valve 30 of the present embodiment has a single high-pressure side conduit 22, and the valve body 36 does not have a switching function for two high-pressure side conduits. And cheap. Further, the valve seat 34 and the conduits 24, 26, and 28 can be fixed while maintaining airtightness by welding by brazing, so that the cost is also low from this point.

  Next, the operation of the air conditioner 10 will be described.

  During the heating operation, the refrigerant flows through the heating cycle as shown in FIG. That is, the refrigerant (not shown) compressed to high temperature and high pressure by the compressor 12 flows into the valve casing 32 through the high pressure side conduit 22, passes through the communication hole 38a of the connecting plate 38, and further flows into the valve. The air flows into the indoor side communication passage 34 b of the seat 34 and flows out from the indoor side conduit 26 to the indoor heat exchanger 18. Thereafter, the refrigerant heats indoors by radiating heat to indoor air in the indoor heat exchanger 18, thereby condensing and liquefying the room, and decompressed by the expansion valve 16. The refrigerant that has been decompressed to low temperature and low pressure flows to the outdoor heat exchanger 14, takes heat from the outdoor air, and is evaporated and gasified. Thereafter, the low-temperature and low-pressure refrigerant flows from the outdoor conduit 28 into the outdoor communication passage 34d of the valve seat 34, passes through the recess 36a of the valve body 36, and flows into the low-pressure communication passage 34c of the valve seat 34. Is returned to the suction side of the compressor 12 through the low-pressure side conduit 24 and compressed again.

  On the other hand, during the cooling operation, the refrigerant flows through the cooling cycle as shown in FIG. That is, the refrigerant that has been compressed by the compressor 12 and has become high temperature and high pressure flows into the valve casing 32 through the high pressure side conduit 22, passes through the outer wall surface 36 b of the valve body 36, and then communicates with the connecting plate 38. The air then passes through the hole 38a, flows into the outdoor communication passage 34d of the valve seat 34, and flows out from the outdoor conduit 28 to the outdoor heat exchanger 14. Thereafter, the refrigerant is condensed and liquefied by releasing heat to the outdoor air in the outdoor heat exchanger 14, and decompressed by the expansion valve 16. The refrigerant that has been depressurized to low temperature and low pressure flows to the indoor heat exchanger 18 and takes heat from the indoor air to evaporate and gasify. At this time, the indoor air is cooled by latent heat of vaporization and the cooling operation is performed. Can do. Thereafter, the low-temperature and low-pressure refrigerant flows into the indoor communication passage 34b of the valve seat 34 from the indoor conduit 26, passes through the recess 36a of the valve body 36, and flows into the low pressure communication passage 34c of the valve seat 34. Is returned to the suction side of the compressor 12 through the low-pressure side conduit 24 and compressed again.

  Next, the heat transfer in the four-way switching valve 30 and the performance of the refrigeration cycle will be described with reference to FIGS. FIG. 5 shows a comparison between the air conditioner equipped with a conventional four-way selector valve and the Mollier diagram during heating of the air conditioner of this embodiment, and FIG. 6 shows the amount of heat transfer during heating of the conventional four-way selector valve. FIG. 7 is a schematic diagram illustrating the conventional air conditioner provided with a four-way switching valve and a Mollier diagram at the time of cooling the air conditioner of the present embodiment. This conventional four-way switching valve has a structure similar to the four-way switching valve of prior art 1, and the high-pressure side conduit is opposed to the center of the upper surface of the valve body as compared with the four-way switching valve 30 of the present embodiment. It is different in that it is connected to a position that is in line with the low temperature side conduit and the valve seat is made of brass that does not contain manganese, and is otherwise the same. In addition, in the Mollier diagrams shown in FIGS. 5 and 7, pressure loss and heat loss in the connecting pipe excluding the four-way valve are omitted for easy understanding of the effects of the present embodiment.

  The Mollier diagram 61 when heating an air conditioner using a conventional four-way switching valve is as shown by the dotted line in FIG. 5, and the Mollier diagram 62 when heating the air conditioner according to the present embodiment is shown as a solid line in FIG. It is shown. In the Mollier diagrams 61 and 62, A ′ and A are compressor parts, B ′ and B are parts from the discharge side of the compressor to the inlet of the indoor heat exchanger, C ′ and C are parts of the indoor heat exchanger, D ′ and D are expansion valve portions, E ′ and E are indoor and outdoor heat exchanger portions, and F ′ and F are portions from the indoor and outdoor heat exchangers to the compressor suction side.

  In the conventional four-way switching valve, since the high-pressure side conduit is connected to a position facing the center of the upper surface of the valve body, the high-temperature refrigerant flowing from the high-pressure side conduit collides with the upper surface of the valve body and is bent greatly. As a result, pressure loss is caused and a high-temperature refrigerant becomes a collision flow that flows toward the valve casing. Therefore, heat transfer from the high-temperature refrigerant to the valve casing around the valve body is promoted, and heat from the high-temperature refrigerant to the low-temperature refrigerant is promoted. Increases movement. For this reason, the portion C 'in the Mollier diagram 61 has been lowered, which has been a cause of a reduction in heating capacity.

On the other hand, the four-way switching valve 30 of the present embodiment is arranged so that the high-pressure side conduit 22 faces the indoor-side conduit 26 and is substantially straight, so that the high-temperature refrigerant flowing from the high-pressure side conduit 22 It will flow to the low temperature side conduit | pipe 24 linearly, and a pressure loss can be reduced significantly compared with the conventional four-way selector valve. Further, since the high-temperature refrigerant does not collide with the upper surface of the valve body, heat transfer from the high-temperature refrigerant to the valve casing around the valve body is suppressed. That is, the portion B ′ in the Mollier diagram 62 is reduced, and thereby the heating efficiency can be improved.

  In the conventional four-way switching valve, the heat transfer from the high-temperature refrigerant flowing into the high-pressure side conduit to the low-temperature refrigerant flowing out from the low-pressure side conduit was analyzed, and it was found that the heat transfer occurred with the amount of heat transfer along the path shown in FIG. As is apparent from FIG. 6, the heat transfer amount through the valve body of the conventional four-way switching valve is as small as 7% of the total heat transfer amount, whereas the heat transfer amount through the valve seat is the entire heat transfer. It was found that the amount was very large at 59%.

  Therefore, in the present embodiment, the valve seat 34 made of a material in which 1 to 4% of manganese is added to brass is used so that the amount of heat transfer from the high-temperature refrigerant to the low-temperature refrigerant through the valve seat 34 is reduced. The heat conductivity of the valve seat 34 of the present embodiment is set to one third or less of the heat conductivity of the valve seat of the conventional four-way switching valve. By reducing the amount of heat transfer from the high-temperature refrigerant to the low-temperature refrigerant in this way, the temperature of the refrigerant supplied to the indoor heat exchanger 18 can be kept high, so that the amount of heat released from the indoor heat exchanger 24 can be increased. Heating capacity can be increased.

  However, if the amount of heat transfer from the high-temperature refrigerant to the low-temperature refrigerant is reduced, the suction temperature of the compressor 12 decreases and the input of the compressor 12 increases. Therefore, in this embodiment, a compressor is used as the compressor 12 in which the increase in the heating capacity due to the reduction in the amount of heat transfer is larger than the increase in the compressor input due to the reduction in the amount of heat transfer. Thereby, the heating efficiency can be improved.

  The Mollier diagram 63 during cooling of an air conditioner using a conventional four-way switching valve is as shown by the dotted line in FIG. 7, and the Mollier diagram 64 during cooling of the air conditioner of the present embodiment is shown as a solid line in FIG. It is shown. In the Mollier diagrams 63 and 64, H ′ and H are compressor parts, I ′ and I are parts from the discharge side of the compressor to the inlet of the indoor / outdoor heat exchanger, and J ′ and J are indoor and outdoor heat exchangers. Portions K ′ and K are expansion valve portions, L ′ and L are indoor heat exchanger portions, and M ′ and M are portions from the indoor heat exchanger to the compressor suction side.

  The four-way switching valve 30 of the present embodiment is arranged so that the high-pressure side conduit 22 faces the indoor-side conduit 26 and is substantially straight, and the high-pressure side conduit 22 passes through the space above the valve body 36 during the cooling operation. Since this is communicated with the outdoor conduit 28, a pressure loss occurs in this portion.

  However, in this embodiment, since the valve seat 34 made of a material in which 1 to 4% of manganese is added to brass is used so that the amount of heat transfer from the high-temperature refrigerant to the low-temperature refrigerant through the valve seat 34 is reduced, compression is performed. The refrigerant temperature supplied to the machine suction side is kept low. And since the pressure of the refrigerant | coolant which flows through an indoor side is low with the increase in the thermal radiation amount of an outdoor side, a high density refrigerant | coolant can be supplied to a compressor. That is, since the refrigerant density increases, the refrigerant circulation amount increases when the compressor is rotated at the same rotational speed. Since the capacity is defined by multiplying the enthalpy difference by the refrigerant circulation amount, the cooling capacity can be increased as a result. Further, in this embodiment, a compressor is used in which the cooling capacity reduction due to the reduction in heat transfer amount is smaller than the reduction in compressor input due to the reduction in heat transfer amount. Thereby, the cooling efficiency can be further improved.

  Also, if the compressor used in the present embodiment has a reduced cooling capacity due to the reduced heat transfer amount, the reduced amount of the compressor input due to the reduced heat transfer amount becomes larger. Even when the efficiency is lowered, the heating efficiency is increased more than the cooling efficiency is decreased. Thereby, the annual energy consumption efficiency (APF) of the air conditioner 10 can be improved. This APF is a numerical value obtained by dividing the total cooling / heating capacity required for one year by the period power consumption (cooling period (kWh) + heating period (kWh)), and is characterized by a high contribution rate of the heating capacity.

  The specific state of the four-way switching valve 30 during heating and cooling will be described. The amount of heat transfer from the high temperature refrigerant to the low temperature refrigerant is larger during heating. The pressure loss and refrigerant temperature decrease until the refrigerant flowing in from the high-pressure side conduit 22 flows out to the indoor-side conduit 26 and the outdoor-side conduit 28 are larger during cooling. Comparing the temperature difference between the indoor conduit 26 and the low pressure side pipe 24 during heating and the temperature difference between the outdoor conduit 28 and the low pressure side conduit 24 during cooling, the temperature difference during heating is larger. Since the rotation speed of the compressor 12 is generally higher during heating, the flow rate when the refrigerant flowing from the high-pressure side conduit 22 flows out to the indoor side conduit 26 and the outdoor side conduit 28 is faster during heating.

  As described above, according to this embodiment, it is possible to provide an air conditioner that can improve efficiency while providing a simple and inexpensive four-way switching valve.

  DESCRIPTION OF SYMBOLS 10 ... Air conditioner, 12 ... Compressor, 14 ... Outdoor heat exchanger, 16 ... Expansion valve (pressure reduction means), 18 ... Indoor heat exchanger, 20 ... Refrigerant piping, 22 ... High pressure side conduit, 24 ... Low pressure side conduit , 26 ... indoor side conduit, 28 ... outdoor side conduit, 30 ... four-way switching valve, 32 ... valve casing, 32a ... cylindrical wall part, 32b ... end wall part, 34 ... valve seat, 34a ... seat surface, 34b ... indoor side Communicating passage, 34c ... Low pressure side communicating passage, 34d ... Outdoor communicating passage, 36 ... Valve element, 36a ... Depression, 36b ... Outer wall surface, 36c ... Edge, 36e ... Sliding surface, 38 ... Connecting plate, 38a ... Communication Hole, 38b ... Communication hole, 40a, 40b ... Piston plate, 50 ... Control device.

Claims (2)

A refrigeration cycle formed by connecting a compressor, a four-way switching valve, an indoor heat exchanger, a decompression means, and an outdoor heat exchanger with refrigerant pipes and filled with refrigerant inside, and the four-way switching valve is switched for cooling and heating operation. And a control device for performing
The four-way switching valve includes a cylindrical valve casing closed at both ends, a metal valve seat disposed in the valve casing so as to extend in the cylinder axial direction and having a planar seat surface, and the valve A valve body arranged to be movable in the cylinder axis direction on the seat surface of the seat, and a copper conduit connected to the valve casing,
The valve seat is provided with an outdoor side communication path, a low pressure side communication path, and an indoor side communication path opened in order in the cylinder axis direction and on the seat surface,
The conduit includes a high-pressure side conduit communicating with a valve casing inner space outside the valve body and a discharge side of the compressor, an outdoor conduit communicating with the outdoor communication passage and the outdoor heat exchanger, A low- pressure side conduit that communicates the low-pressure side communication passage and the suction side of the compressor, and an indoor-side conduit that communicates the indoor-side communication passage and the indoor heat exchanger,
The valve body communicates the high-pressure side conduit and the indoor-side conduit during heating to flow high-temperature refrigerant, and communicates the low-pressure side conduit and the outdoor-side conduit to flow low-temperature refrigerant, and during cooling, the high-pressure side flows. conduit and said chamber outer conduit communicates communicating with said interior side conduit and the low-pressure side conduit with flow temperature refrigerant is moved to pass the low temperature refrigerant,
The high-pressure side conduit is disposed so as to face the indoor-side conduit and be substantially straight.
In the air conditioner, wherein the indoor-side conduit, the low-pressure side conduit, and the outdoor-side conduit are welded to the wall surfaces of the indoor-side communication path, the outdoor-side communication path, and the low-pressure side communication path, respectively.
As the valve seat, using a valve seat made of a material obtained by adding 1 to 4% of manganese to brass so as to reduce the amount of heat transfer during heating from the high-temperature refrigerant to the low-temperature refrigerant through the valve seat,
Characterized by using a compressor is larger than the amount of increase in the compressor input by reducing the increment is amount of heat transfer during the heating of the heating capacity by reducing the amount of heat transfer during the heating as the compressor Air conditioner.   The interior conduit, the low-pressure side conduit, and the outdoor conduit according to claim 1 are brazed to the wall surfaces of the indoor-side communication passage, the outdoor-side communication passage, and the low-pressure side communication passage, respectively. Air conditioner to do.

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