JP2012242047A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that can perform defrosting of an outdoor heat exchanger while continuing heating operation.SOLUTION: In the air conditioner 300, a flow path switching valve 51 has a switching mechanism for performing switching to one of a first mode, a second mode and a third mode. In the first mode, a refrigerant which enters from an expansion valve 7 is made to flow into both a first outdoor heat exchanging section 46a and a second outdoor heat exchanging section 46b. In the second mode, the refrigerant entering from the expansion valve 7 is made to flow into the first outdoor heat exchanging section 46a and the refrigerant entering from a bypass path 61 is made to flow into the second outdoor heat exchanging section 46b. In the third mode, the refrigerant entering from the expansion valve 7 is made to flow into the second outdoor heat exchanging section 46b and the refrigerant entering from the bypass path 61 is made to flow into the first outdoor heat exchanging section 46a. A controlling section 8 switches the flow path switching valve 51 to the second mode or the third mode when performing defrosting operation, and opens an on-off valve 71 of the bypass path 61. The on-off valve 71 is arranged on the bypass path 61.

Description

  The present invention relates to an air conditioner provided with a flow path switching valve that switches a fluid flow path or distributes fluid in multiple directions.

  When the outdoor heat exchanger is frosted during the heating operation of the air conditioner, as a means to eliminate the frost formation, there is a method in which the high-temperature refrigerant that has exited the compressor bypasses the condenser and flows to the evaporator. Patent Document 1 (Japanese Patent Application Laid-Open No. 11-132603) discloses.

  However, in the air conditioner disclosed in Patent Document 1, since the warm air supply is stopped every time the defrosting operation is performed, there is a high possibility that the user will feel uncomfortable.

  The subject of this invention is providing the air conditioner which can defrost an outdoor heat exchanger, continuing heating operation.

  An air conditioner according to a first aspect of the present invention is an air conditioner that uses a vapor compression refrigeration cycle in which refrigerant circulates in the order of a compressor, a condenser, a decompressor, and an evaporator, and is an indoor heat exchanger And an outdoor heat exchanger, a flow path switching valve, a bypass path, an on-off valve, and a control unit. An indoor heat exchanger becomes a condenser at the time of heating operation, and becomes an evaporator at the time of cooling operation. The outdoor heat exchanger serves as an evaporator during heating operation, and serves as a condenser during cooling operation. The flow path switching valve is disposed between the pressure reducer and the outdoor heat exchanger. The bypass path guides a part of the refrigerant discharged from the compressor to the flow path switching valve. The on-off valve is disposed in the bypass path. The control unit controls at least the flow path switching valve and the on-off valve. The outdoor heat exchanger has a first outdoor heat exchange part and a second outdoor heat exchange part connected in parallel with the first outdoor heat exchange part. The flow path switching valve includes a first valve chamber, a second valve chamber, a valve element, and a drive unit. The first valve chamber has a planar first valve seat provided with a plurality of ports, and can communicate with the decompressor, the first outdoor heat exchange unit, and the second outdoor heat exchange unit via the ports. The second valve chamber has a planar second valve seat provided with a plurality of ports, and can communicate with at least the bypass path via the ports. The valve body has a flow pipe that partitions the first valve chamber and the second valve chamber and has one end close to the first valve seat and the other end close to the second valve seat. The drive unit rotates the valve body. Furthermore, the flow path switching valve performs switching to any one of the first form, the second form, and the third form. The first form is that one end of the flow pipe does not face any port of the first valve seat (201), so that the refrigerant entered from the decompressor is supplied to the first outdoor heat exchange unit and the second outdoor heat exchange unit. It is a form that flows to both sides. In the second mode, one end of the flow pipe is opposed to the port of the first valve seat that communicates with the second outdoor heat exchanger, and the other end is opposed to the port of the second valve seat that communicates with the bypass passage. It is a form which flows the refrigerant | coolant which entered from the container to the 1st outdoor heat exchange part, and flows the refrigerant | coolant which entered from the bypass path to the 2nd outdoor heat exchange part. In the third mode, one end of the flow pipe faces the port of the first valve seat that leads to the first outdoor heat exchange section, and the other end faces the port of the second valve seat that leads to the bypass path, thereby reducing the pressure. It is a form which flows the refrigerant | coolant which entered from the container to the 2nd outdoor heat exchange part, and flows the refrigerant | coolant which entered from the bypass path to the 1st outdoor heat exchange part. And a control part switches a flow-path switching valve to a 2nd form or a 3rd form, and opens an on-off valve, when performing a defrost operation.

  In this air conditioner, a part of the outdoor heat exchanger can be used to continue the heating operation, while the other part can be defrosted by introducing a high-pressure / high-temperature refrigerant from the bypass. Therefore, defrosting is performed without stopping the warm air supply.

  An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, and further includes an outdoor temperature sensor that detects an outdoor temperature. The control unit closes the on-off valve when the temperature detected by the outdoor temperature sensor is equal to or higher than a predetermined temperature.

  In this air conditioner, when the outdoor temperature is not below the freezing point (preferably 5 ° C or higher), frost naturally melts. Therefore, the open / close valve is closed and defrosting is performed without introducing high-pressure / high-temperature refrigerant. be able to.

  The air conditioner which concerns on the 3rd viewpoint of this invention is an air conditioner which concerns on a 1st viewpoint, Comprising: The 2nd bypass path is further provided. The second bypass path connects the outlet of the outdoor heat exchanger during heating operation and one port of the second valve chamber. The flow path switching valve can be switched to any one of the first form, the second form, the third form, and the fourth form. In addition, the 4th form is a form which flows the refrigerant | coolant which entered from the bypass path to the 2nd bypass path because the end of a flow pipe does not oppose any port of a 2nd valve seat. And a control part switches to a 4th form, before switching a flow-path switching valve to a 1st form.

  When the outside air temperature is low, the compressor immediately before the start of heating operation is cold, and the heat capacity of the compressor is large, so it is constant from the start of heating operation until the high-temperature refrigerant circulates in the indoor heat exchanger Takes time. Therefore, it is preferable to quickly increase the compressor temperature from the viewpoint of heating operation performance.

  In this air conditioner, the control unit switches the flow path switching valve to the fourth mode, whereby a part of the high-pressure and high-temperature gas refrigerant discharged from the compressor is bypassed, the flow path switching valve, and the second bypass. Since it flows in order of a path and returns to a compressor again, a compressor temperature rises rapidly.

  The air conditioner which concerns on the 4th viewpoint of this invention is an air conditioner which concerns on a 3rd viewpoint, Comprising: An indoor heat exchanger has a 1st indoor heat exchange part, a 2nd indoor heat exchange part, a pressure reduction part, have. The decompression unit is connected between the first indoor heat exchange unit and the second indoor heat exchange unit. The flow path switching valve can be switched to any one of the first form, the second form, the third form, the fourth form, and the fifth form. In the fifth embodiment, the first end of the flow pipe faces the port of the first valve seat leading to the decompressor, and the other end faces the port of the second valve seat leading to the second bypass passage. This is a mode in which the refrigerant that has entered from the two bypass passages flows to the decompressor. And a control part switches a flow-path switching valve to a 5th form, when performing the reheat dehumidification operation which flows the refrigerant | coolant discharged from the compressor by the cycle contrary to the time of heating operation to a 1st indoor heat exchange part.

  In this air conditioner, only the first indoor heat exchanger of the indoor heat exchanger becomes a condenser during the reheat dehumidification operation. Since the first indoor heat exchange section has a smaller capacity than the outdoor heat exchanger, surplus refrigerant is generated, but the refrigerant discharged from the compressor may flow into the outdoor heat exchanger from the inlet side of the outdoor heat exchanger. The surplus refrigerant is stored in the outdoor heat exchanger. Therefore, the first indoor heat exchange section is not excessively occupied by the liquid refrigerant, and the condenser capacity can be effectively utilized by suppressing the increase in the high pressure, that is, the energy-saving reheat dehumidification operation that suppresses the input of the compressor. it can.

  In the air conditioner according to the first aspect of the present invention, defrosting is performed while continuing the heating operation using a part of the outdoor heat exchanger, so that the warm air supply does not stop.

  In the air conditioner according to the second aspect of the present invention, defrosting can be performed without closing the on-off valve and introducing high-pressure / high-temperature refrigerant.

  In the air conditioner according to the third aspect of the present invention, part of the high-pressure and high-temperature gas refrigerant discharged from the compressor flows in the order of the bypass path, the flow path switching valve, and the second bypass path, and again the compressor The compressor temperature rises quickly.

  In the air conditioner according to the fourth aspect of the present invention, the first indoor heat exchange section is not excessively occupied by the liquid refrigerant, and the condenser capacity can be effectively utilized while suppressing an increase in high pressure. Energy-saving reheat dehumidification operation that suppresses

The block diagram of the air conditioner which concerns on one Embodiment of this invention. The perspective view of the flow-path switching valve used for the air conditioner which concerns on this embodiment. Sectional drawing of a flow-path switching valve when the 1st valve chamber switched to the 1st form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 2nd valve chamber switched to the 1st form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of the flow-path switching valve switched to the 1st form. Sectional drawing of a flow-path switching valve when the 1st valve chamber switched to the 2nd form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 2nd valve chamber switched to the 2nd form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 1st valve chamber switched to the 3rd form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 2nd valve chamber switched to the 3rd form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 1st valve chamber switched to the 4th form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 2nd valve chamber switched to the 4th form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 1st valve chamber switched to the 5th form is cut | disconnected by the surface orthogonal to the central axis of a main body. Sectional drawing of a flow-path switching valve when the 2nd valve chamber switched to the 5th form is cut | disconnected by the surface orthogonal to the central axis of a main body. The path | route diagram which shows the communication state between the pipe connection parts of the flow-path switching valve switched to the 1st form. The route diagram which shows the communication state between the pipe connection parts of the flow-path switching valve switched to the 2nd form. The route diagram which shows the communication state between the pipe connection parts of the flow-path switching valve switched to the 3rd form. The route diagram which shows the communication state between the pipe connection parts of the flow-path switching valve switched to the 4th form. The route diagram which shows the communication state between the pipe connection parts of the flow-path switching valve switched to the 5th form.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

(1) Overall Configuration of Air Conditioner 300 FIG. 1 is a configuration diagram of an air conditioner 300 according to an embodiment of the present invention. In FIG. 1, the air conditioner 300 includes an indoor unit 4, an outdoor unit 6, and a control unit 8. The indoor unit 4 and the outdoor unit 6 are connected by a refrigerant communication pipe to constitute a vapor compression refrigerant circuit.

(2) Detailed configuration (2-1) Indoor unit 4
The indoor unit 4 includes an indoor heat exchanger 40. The indoor heat exchanger 40 is a fin-and-tube heat exchanger, and heats air by functioning as a refrigerant condenser during heating operation. In the cooling operation, the air is cooled by functioning as a refrigerant evaporator. The indoor heat exchanger 40 includes a first indoor heat exchange unit 40a, a second indoor heat exchange unit 40b connected in series with the first indoor heat exchange unit 40a, and the first indoor heat exchange unit 40a and the second indoor heat exchange. It has the 2nd expansion valve 40c connected between the parts 40b.

(2-2) Outdoor unit 6
The outdoor unit 6 is mainly installed outdoors, and includes a four-way switching valve 2, a compressor 5, an expansion valve 7, an outdoor heat exchanger 46, and a flow path switching valve 51.

(2-2-1) Four-way selector valve 2
The four-way switching valve 2 is a valve that switches the direction of the refrigerant flow when switching between the cooling operation and the heating operation. During the cooling operation, the four-way switching valve 2 connects the discharge side of the compressor 5 and the gas side of the outdoor heat exchanger 46 and connects the suction side of the compressor 5 and the gas side of the indoor heat exchanger 40. . During the heating operation, the four-way switching valve 2 connects the discharge side of the compressor 5 and the gas side of the indoor heat exchanger 40 and connects the suction side of the compressor 5 and the gas side of the outdoor heat exchanger 46. Connecting.

(2-2-2) Compressor 5
The compressor 5 is a variable capacity compressor adopting an inverter system, and sucks low-pressure gas refrigerant, compresses it into high-pressure gas refrigerant, and discharges it.

(2-2-3) Expansion valve 7
The expansion valve 7 decompresses the high-pressure liquid refrigerant radiated in the indoor heat exchanger 40 before sending it to the outdoor heat exchanger 46 during the heating operation. Further, the expansion valve 7 decompresses the high-pressure liquid refrigerant radiated in the outdoor heat exchanger 46 before sending it to the indoor heat exchanger 40 during the cooling operation.

(2-2-4) Outdoor heat exchanger 46
The outdoor heat exchanger 46 is a heat exchanger that functions as a refrigerant condenser during the cooling operation and functions as a refrigerant evaporator during the heating operation. The outdoor heat exchanger 46 includes a first outdoor heat exchange unit 46a and a second outdoor heat exchange unit 46b connected in parallel with the first outdoor heat exchange unit 46a.

(2-2-5) Flow path switching valve 51
FIG. 2 is a perspective view of the flow path switching valve 51 used in the air conditioner 300 according to the present embodiment. In FIG. 2, the flow path switching valve 51 includes a main body 10, a valve body 20, and a motor 30. The main body 10 is a cylindrical member whose both ends are closed by separate members. For convenience of explanation, the cylindrical portion is referred to as a body portion 10a of the main body 10, one of both ends is referred to as a first end portion 10b, and the other is referred to as a second end portion 10c.

  In the first end portion 10b, three holes leading from the outer periphery to the body portion 10a are formed, and pipes for pipe connection are fitted into each hole and brazed. Each of these three pipes is referred to as a first pipe connection part 11, a third pipe connection part 13, and a fifth pipe connection part 15.

  Further, the second end portion 10c is provided with two holes leading from the outer periphery to the body portion 10a, and pipes for pipe connection are fitted into each hole and brazed. These two pipes are called a second pipe connection part 12 and a fourth pipe connection part 14, respectively. The first pipe connection part 11, the second pipe connection part 12, the third pipe connection part 13, the fourth pipe connection part 14, and the fifth pipe connection part 15 are inlets when the refrigerant enters the flow path switching valve 51. , And an outlet when the refrigerant exits the flow path switching valve 51.

(3) Detailed configuration of the flow path switching valve 51 The first pipe connection portion 11, the third pipe connection portion 13, and the fifth pipe connection portion 15 are the same as viewed from the bottom surface (the second end portion 10c side) of the main body 10. It is arrange | positioned around the trunk | drum 10a in the height position. Similarly, the 2nd piping connection part 12 and the 4th piping connection part 14 are arrange | positioned around the trunk | drum 10a in the same height position seeing from the bottom face of the main body 10. FIG.

  In FIG. 1, the first pipe connection portion 11 is connected to the expansion valve 7. The third pipe connection part 13 is connected to the first outdoor heat exchange part 46 a of the outdoor heat exchanger 46. The fifth pipe connection unit 15 is connected to the second outdoor heat exchange unit 46 b of the outdoor heat exchanger 46.

  Further, the second pipe connection part 12 is connected to the second bypass path 62. The second bypass path 62 is a refrigerant pipe that connects the outlet of the outdoor heat exchanger 46 and the flow path switching valve 51 during the heating operation. Further, the fourth pipe connection portion 14 is connected to the bypass path 61. The bypass path 61 is a refrigerant pipe that guides a part of the refrigerant discharged from the compressor 5 to the flow path switching valve 51. An on-off valve 71 is provided in the middle of the bypass passage 61.

  The inside of the main body 10 is a cylindrical cavity, and a valve body 20 that rotates along the circumferential surface is accommodated. The valve body 20 is a disk-shaped rotating body and partitions the inside of the main body 10 into a first valve chamber 101 and a second valve chamber 102. The first pipe connection part 11, the third pipe connection part 13, and the fifth pipe connection part 15 communicate with the first valve chamber 101. In addition, the second pipe connection part 12 and the fourth pipe connection part 14 communicate with the second valve chamber 102. Furthermore, the valve body 20 is driven by the motor 30 and switches to the first form, the second form, the third form, the fourth form, and the fifth form according to the rotation angle of the motor 30. First, a 1st form is demonstrated using FIG. 3A and 3B.

  3A is a cross-sectional view of the flow path switching valve when the first valve chamber 101 that has been switched to the first configuration is cut along a plane that is orthogonal to the central axis of the main body 10, and FIG. 3B is that of the first configuration that has been switched to the first configuration. 4 is a cross-sectional view of the flow path switching valve when the second valve chamber 102 is cut along a plane orthogonal to the central axis of the main body 10.

  In FIG. 3A, the 3rd piping connection part 13 is being fixed to the position 90 degrees away from the 1st piping connection part 11 clockwise with respect to the central axis of the trunk | drum 10a. The 5th pipe connection part 15 is being fixed to the position 90 degrees away from the 1st pipe connection part 11 counterclockwise with respect to the central axis of the trunk | drum 10a. In FIG. 3B, the 4th piping connection part 14 is being fixed to the position 180 degrees away from the 2nd piping connection part 12 clockwise with respect to the central axis of the trunk | drum 10a. The valve body 20 has a flow pipe 200 that penetrates the first valve chamber 101 and the second valve chamber 102. The cross section of the flow pipe 200 is elliptical.

  FIG. 4 is a cross-sectional view of the flow path switching valve switched to the first configuration. In FIG. 4, the first valve chamber 101 has a planar first valve seat 201 provided with ports of the first pipe connection part 11, the third pipe connection part 13, and the fifth pipe connection part 15. ing. The second valve chamber 102 has a planar second valve seat 202 in which the ports of the second pipe connection part 12 and the fourth pipe connection part 14 are provided.

  One end of the flow pipe 200 is close to the first valve seat 201, and any one of the ports of the first pipe connection part 11, the third pipe connection part 13, and the fifth pipe connection part 15 by the rotation of the valve body 20. Can confront. Further, the other end is close to the second valve seat 202 and can be opposed to any port of the second pipe connection part 12 and the fourth pipe connection part 14 by the rotation of the valve body 20.

  The motor 30 is located on the first end portion 10b side of the main body 10, and the rotation shaft passes through the first end portion 10b and is connected to the valve body 20. In FIG. 4, only the motor 30 is indicated by a two-dot chain line so that it can be distinguished from other components. The valve body 20 is driven by a motor 30 and switches to one of the first form, the second form, the third form, the fourth form, and the fifth form according to the rotation angle of the motor 30.

  Here, the 1st form is a form in which the valve body 20 makes the 1st piping connection part 11, the 3rd piping connection part 13, and the 5th piping connection part 15 communicate. The second form is a form in which the valve body 20 communicates only the first pipe connection part 11 and the third pipe connection part 13 and communicates only the fourth pipe connection part 14 and the fifth pipe connection part 15. is there. The third form is a form in which the valve body 20 communicates only the first pipe connection part 11 and the fifth pipe connection part 15 and communicates only the fourth pipe connection part 14 and the third pipe connection part 13. is there. A 4th form is a form which makes the 4th piping connection part 14 and the 2nd piping connection part 12 communicate. A 5th form is a form which makes the 2nd piping connection part 12 and the 1st piping connection part 11 communicate. Hereinafter, the structure for forming each form is demonstrated.

(3-1) First form of flow path switching valve 51 As shown in FIGS. 3A and 3B, the flow path switching valve 51 is switched to the first form, so that in the first valve chamber 101, the flow pipe 200 One end does not face any port of the first pipe connection part 11, the third pipe connection part 13, and the fifth pipe connection part 15. The refrigerant that has flowed in from the first pipe connection part 11 is divided into a refrigerant that goes to the third pipe connection part 13 and a refrigerant that goes to the fifth pipe connection part 15. In FIG. 1, the refrigerant that has exited the third pipe connection portion 13 is sent to the first outdoor heat exchange portion 46 a of the outdoor heat exchanger 46, and the refrigerant that has exited the fifth pipe connection portion 15 has the first temperature of the outdoor heat exchanger 46. 2 is sent to the heat exchanger 46b.

  In the second valve chamber 102, the other end of the flow pipe 200 faces the fourth pipe connection portion 14. Since the refrigerant that has entered from the fourth pipe connection portion 14 is blocked by the flow pipe 200 and cannot flow to the second pipe connection section 12, the refrigerant passes through the flow pipe 200 toward the first valve chamber 101. However, since the refrigerant is blocked by the first valve seat 201, the refrigerant cannot flow through any of the first pipe connection part 11, the third pipe connection part 13, and the fifth pipe connection part 15.

  FIG. 9A is a route diagram illustrating a communication state between the pipe connection portions of the flow path switching valve 51 switched to the first form. In FIG. 9A, when the flow path switching valve 51 is switched to the first configuration, the first pipe connection part 11 and the third pipe connection part 13 communicate with each other, and the first pipe connection part 11 and the fifth pipe connection are connected. The part 15 communicates. Hereinafter, when the flow of the refrigerant passing through the flow path switching valve 51 switched to the first form is described, reference is made to FIG. 9A.

(3-2) Second Mode of Channel Switching Valve 51 Next, FIG. 5A shows channel switching when the first valve chamber 101 switched to the second mode is cut along a plane orthogonal to the central axis of the main body 10. FIG. 5B is a cross-sectional view of the flow path switching valve 51 when the second valve chamber 102 switched to the second configuration is cut along a plane orthogonal to the central axis of the main body 10.

  5A and 5B, the flow path switching valve 51 is switched to the second configuration, so that one end of the flow pipe 200 faces the fifth pipe connection portion 15 in the first valve chamber 101. The refrigerant flowing in from the first pipe connection portion 11 is directed to the third pipe connection portion 13 because the fifth pipe connection portion 15 side is blocked by the flow pipe 200. In FIG. 1, the refrigerant that has exited the third pipe connection portion 13 is sent to the first outdoor heat exchange portion 46 a of the outdoor heat exchanger 46.

  In the second valve chamber 102, the other end of the flow pipe 200 faces the fourth pipe connection portion 14. Since the refrigerant that has entered from the fourth pipe connection portion 14 is blocked by the flow pipe 200 and cannot flow to the second pipe connection section 12, the refrigerant passes through the flow pipe 200 toward the first valve chamber 101. Since the circulation pipe 200 communicates with the fifth pipe connection part 15, the refrigerant that has passed through the circulation pipe 200 is sent to the second outdoor heat exchange part 46 b of the outdoor heat exchanger 46 via the fifth pipe connection part 15. It is done.

  FIG. 9B is a route diagram illustrating a communication state between the pipe connection portions of the flow path switching valve 51 switched to the second mode. In FIG. 9b, when the flow path switching valve 51 is switched to the second configuration, the first pipe connection portion 11 and the third pipe connection portion 13 communicate with each other, and the fourth pipe connection portion 14 and the fifth pipe connection. The part 15 communicates. Hereinafter, when the flow of the refrigerant passing through the flow path switching valve 51 switched to the second mode is described, reference is made to FIG. 9B.

(3-3) Third Mode of Channel Switching Valve 51 Next, FIG. 6A shows channel switching when the first valve chamber 101 switched to the third mode is cut along a plane orthogonal to the central axis of the main body 10. FIG. 6B is a cross-sectional view of the flow path switching valve 51 when the second valve chamber 102 switched to the third configuration is cut along a plane orthogonal to the central axis of the main body 10.

  6A and 6B, the flow path switching valve 51 is switched to the third configuration, so that one end of the flow pipe 200 faces the third pipe connection portion 13 in the first valve chamber 101. The refrigerant that has flowed in from the first pipe connection portion 11 is directed to the fifth pipe connection portion 15 because the third pipe connection portion 13 side is blocked by the flow pipe 200. In FIG. 1, the refrigerant that has exited the fifth pipe connection portion 15 is sent to the second outdoor heat exchange portion 46 b of the outdoor heat exchanger 46.

  In the second valve chamber 102, the other end of the flow pipe 200 faces the fourth pipe connection portion 14. Since the refrigerant that has entered from the fourth pipe connection portion 14 is blocked by the flow pipe 200 and cannot flow to the second pipe connection section 12, the refrigerant passes through the flow pipe 200 toward the first valve chamber 101. Since the circulation pipe 200 communicates with the third pipe connection part 13, the refrigerant that has passed through the circulation pipe 200 is sent to the first outdoor heat exchange part 46 a of the outdoor heat exchanger 46 via the third pipe connection part 13. It is done.

  FIG. 9C is a route diagram illustrating a communication state between the pipe connection portions of the flow path switching valve 51 switched to the third mode. In FIG. 9C, when the flow path switching valve 51 is switched to the third configuration, the first pipe connection portion 11 and the fifth pipe connection portion 15 communicate with each other, and the fourth pipe connection portion 14 and the third pipe connection. The part 13 communicates. Hereinafter, when the flow of the refrigerant passing through the flow path switching valve 51 switched to the third mode is described, reference is made to FIG. 9C.

(3-4) Fourth Mode of Channel Switching Valve 51 Next, FIG. 7A shows channel switching when the first valve chamber 101 switched to the fourth mode is cut along a plane orthogonal to the central axis of the main body 10. FIG. 7B is a cross-sectional view of the flow path switching valve 51 when the second valve chamber 102 switched to the fourth form is cut along a plane orthogonal to the central axis of the main body 10.

  7A and 7B, the flow path switching valve 51 is switched to the fourth configuration, so that one end of the flow pipe 200 faces the fifth pipe connection portion 15 in the first valve chamber 101. Since the fifth pipe connection part 15 side is blocked by the flow pipe 200, the first pipe connection part 11 and the third pipe connection part 13 communicate with each other. However, in the fourth embodiment, the refrigerant does not flow through either the first pipe connection portion 11 or the third pipe connection portion 13.

  In the second valve chamber 102, the other end of the flow pipe 200 does not face either the second pipe connection part 12 or the fourth pipe connection part 14, so that the refrigerant entering from the fourth pipe connection part 14 is blocked. It flows to the 2nd piping connection part 12 without being stopped. In FIG. 1, the refrigerant that has exited the second pipe connection portion 12 is sent to the suction side of the compressor 5 via the second bypass passage 62.

  FIG. 9D is a route diagram illustrating a communication state between the pipe connection portions of the flow path switching valve 51 switched to the fourth mode. In FIG. 9D, the 4th pipe connection part 14 and the 2nd pipe connection part 12 are connected by the flow-path switching valve 51 switching to the 4th form. Hereinafter, when the flow of the refrigerant passing through the flow path switching valve 51 switched to the fourth mode is described, reference is made to FIG. 9D.

(3-5) Fifth Mode of Channel Switching Valve 51 Next, FIG. 8A shows channel switching when the first valve chamber 101 switched to the fifth mode is cut along a plane orthogonal to the central axis of the main body 10. FIG. 8B is a cross-sectional view of the flow path switching valve 51 when the second valve chamber 102 switched to the fifth form is cut along a plane orthogonal to the central axis of the main body 10.

  8A and 8B, the flow path switching valve 51 is switched to the fifth configuration, so that one end of the flow pipe 200 faces the first pipe connection portion 11 in the first valve chamber 101. Since the third pipe connection part 13 side and the fifth pipe connection part 15 side are blocked by the flow pipe 200, the first pipe connection part 11 is either the third pipe connection part 13 or the fifth pipe connection part 15. It does not communicate with either.

  In the second valve chamber 102, the other end of the flow pipe 200 faces the second pipe connection portion 12. Since the refrigerant that has entered from the second pipe connection part 12 is blocked by the flow pipe 200 and cannot flow to the fourth pipe connection part 14, the refrigerant passes through the flow pipe 200 toward the first valve chamber 101. Since the flow pipe 200 communicates with the first pipe connection portion 11, the refrigerant that has passed through the flow pipe 200 is sent to the expansion valve 7 via the first pipe connection portion 11.

  FIG. 9E is a route diagram illustrating a communication state between the pipe connection portions of the flow path switching valve 51 switched to the fifth mode. In FIG. 9E, when the flow path switching valve 51 is switched to the fifth configuration, the second pipe connection part 12 and the first pipe connection part 11 communicate with each other. Hereinafter, when the flow of the refrigerant passing through the flow path switching valve 51 switched to the fifth mode is described, reference is made to FIG. 9E.

(4) Refrigerant Flow During Operation (4-1) Refrigerant Flow During Heating Operation Here, the refrigerant flow during heating operation will be described with reference to FIGS. 1 and 9A. In FIG. 1, the control unit 8 switches the four-way switching valve 2 to a heating operation path (indicated by a solid line), connects the discharge side of the compressor 5 and the gas side of the indoor heat exchanger 40, and the compressor 5. Are connected to the gas side of the outdoor heat exchanger 46. Further, the control unit 8 narrows the opening of the expansion valve 7 to such an extent that the refrigerant is depressurized, closes the on-off valve 71, sets the second expansion valve 40c to an opening not intended to be fully opened or depressurized, The path switching valve 51 is switched to the first form shown in FIG. 9A.

  Under the above conditions, the refrigerant is sucked into the compressor 5 and is discharged after being compressed to a high pressure. The high-pressure refrigerant discharged from the compressor 5 is sent to the indoor heat exchanger 40 through the four-way switching valve 2. In addition, since the bypass path 61 is branched from the middle of the pipe connecting the compressor 5 and the four-way switching valve 2, a part of the refrigerant discharged from the compressor 5 tends to flow into the bypass path 61. Since the on-off valve 71 is closed, the refrigerant does not flow through the bypass passage 61.

  In the indoor heat exchanger 40, since the second expansion valve 40c is opened to the extent that it is not intended to be fully opened or depressurized, both the first indoor heat exchanger 40a and the second indoor heat exchanger 40b function as a condenser. The high-pressure refrigerant condensed in the indoor heat exchanger 40 is sent to the expansion valve 7 and depressurized to a low pressure, and enters the first pipe connection portion 11 of the flow path switching valve 51. Since the flow path switching valve 51 is switched to the first form, the first pipe connection part 11 and the third pipe connection part 13 communicate with each other, and the first pipe connection part 11 and the fifth pipe connection part 15 are connected. Communicate. The refrigerant is divided into a refrigerant directed to the third pipe connection part 13 and a refrigerant directed to the fifth pipe connection part 15, and both the first outdoor heat exchange part 46 a and the second outdoor heat exchange part 46 b of the outdoor heat exchanger 46. Flowing into.

  The refrigerant evaporates by exchanging heat with outdoor air in each of the first outdoor heat exchanger 46a and the second outdoor heat exchanger 46b of the outdoor heat exchanger 46. The low-pressure refrigerant evaporated in the outdoor heat exchanger 46 is again sucked into the compressor 5 through the four-way switching valve 2.

(4-2) Flow of Refrigerant During Cooling Operation Here, the flow of the refrigerant during the cooling operation will be described with reference to FIGS. 1 and 9A. In FIG. 1, the control unit 8 switches the four-way switching valve 2 to a cooling operation path (indicated by a dotted line), connects the discharge side of the compressor 5 and the gas side of the outdoor heat exchanger 46, and the compressor 5. And the gas side of the indoor heat exchanger 40 are connected.

  Further, the control unit 8 narrows the opening of the expansion valve 7 to such an extent that the refrigerant is depressurized, closes the on-off valve 71, sets the second expansion valve 40c to an opening not intended to be fully opened or depressurized, The path switching valve 51 is switched to the first form shown in FIG. 9A.

  Under the above conditions, the refrigerant is sucked into the compressor 5 and is discharged after being compressed to a high pressure. The high-pressure refrigerant discharged from the compressor 5 is sent to the outdoor heat exchanger 46 through the four-way switching valve 2. In addition, since the bypass path 61 is branched from the middle of the pipe connecting the compressor 5 and the four-way switching valve 2, a part of the refrigerant discharged from the compressor 5 tends to flow into the bypass path 61. Since the on-off valve 71 is closed, the refrigerant does not flow through the bypass passage 61.

  The refrigerant is divided into the refrigerant entering the first outdoor heat exchange section 46a and the refrigerant entering the second outdoor heat exchange section 46b at the entrance of the outdoor heat exchanger 40, and the first outdoor heat exchange section 46a and the second outdoor heat exchange section are exchanged. In each part 46b, it condenses by exchanging heat with outdoor air.

  The high-pressure refrigerant condensed in the first outdoor heat exchange part 46 a flows into the third pipe connection part 13 of the flow path switching valve 51. Further, the high-pressure refrigerant condensed in the second outdoor heat exchange part 46 b flows into the fifth pipe connection part 15 of the flow path switching valve 51. Since the flow path switching valve 51 is switched to the first form, the first pipe connection part 11 and the third pipe connection part 13 communicate with each other, and the first pipe connection part 11 and the fifth pipe connection part 15 are connected. Communicate.

  The refrigerant that has flowed into the third pipe connection part 13 and the fifth pipe connection part 15 merges inside the flow path switching valve 51 and reaches the expansion valve 7 through the first pipe connection part 11. The refrigerant is decompressed to a low pressure by the expansion valve 7 and enters the indoor heat exchanger 40.

  In the indoor heat exchanger 40, since the second expansion valve 40c is opened to the extent that it is not intended to be fully opened or depressurized, both the first indoor heat exchanger 40a and the second indoor heat exchanger 40b function as an evaporator. The low-pressure refrigerant evaporated in the indoor heat exchanger 40 is again sucked into the compressor 5 through the four-way switching valve 2.

(4-3) Flow of Refrigerant During Defrosting Operation Here, the flow of the refrigerant during the defrosting operation will be described with reference to FIGS. 1, 9B, and 9C. As a precondition, the controller 8 determines that the outdoor heat exchanger 46 has been frosted during the heating operation, switches the flow path switching valve 51 to the second form shown in FIG. 9B, and opens the on-off valve 71. The states of the four-way switching valve 2, the expansion valve 7 and the second expansion valve 40c are maintained during the heating operation.

  Under the above conditions, the refrigerant is sucked into the compressor 5 and is discharged after being compressed to a high pressure. The high-pressure refrigerant discharged from the compressor 5 is sent to the indoor heat exchanger 40 through the four-way switching valve 2. Further, since the bypass passage 61 branches off from the middle of the pipe connecting the compressor 5 and the four-way switching valve 2, a part of the refrigerant discharged from the compressor 5 enters the bypass passage 61. Since the on-off valve 71 is open, the refrigerant flows through the bypass passage 61 and is sent to the fourth pipe connection portion 14 of the flow path switching valve 51.

  In the indoor heat exchanger 40, since the second expansion valve 40c is opened to the extent that it is not intended to be fully opened or depressurized, both the first indoor heat exchanger 40a and the second indoor heat exchanger 40b function as a condenser. The high-pressure refrigerant condensed in the indoor heat exchanger 40 is sent to the expansion valve 7 and depressurized to a low pressure, and enters the first pipe connection portion 11 of the flow path switching valve 51. Since the flow path switching valve 51 is switched to the second configuration, the first pipe connection part 11 and the third pipe connection part 13 communicate with each other, and the fourth pipe connection part 14 and the fifth pipe connection part 15 are connected. Communicate. Therefore, the low-pressure refrigerant entering from the expansion valve 7 flows to the first outdoor heat exchange unit 46a, and the high-temperature / high-pressure refrigerant entering from the bypass passage 61 flows to the second outdoor heat exchange unit 46b.

  The low-pressure refrigerant evaporates by exchanging heat with outdoor air in the first outdoor heat exchange section 46a. The high-temperature and high-pressure refrigerant dissipates heat in the second outdoor heat exchange unit 46b and melts frost adhering to the surface of the second outdoor heat exchange unit 46b. The refrigerant evaporated in the first outdoor heat exchange unit 46a and the refrigerant dissipated in the second outdoor heat exchange unit 46b merge at the outlet of the outdoor heat exchanger 46, and again enter the compressor 5 through the four-way switching valve 2. Inhaled.

  When the controller 8 determines that the frost in the second outdoor heat exchanger 46b has melted, for example, when the controller 8 determines that the frost has melted from the temperature sensor installed in the second outdoor heat exchanger 46b, the flow path switching valve 51 Is switched to the third mode. At this time, the 1st piping connection part 11 and the 5th piping connection part 15 are connected, and the 4th piping connection part 14 and the 3rd piping connection part 13 are connecting. Therefore, the low-pressure refrigerant entering from the expansion valve 7 flows to the second outdoor heat exchange unit 46b, and the high-temperature and high-pressure refrigerant entering from the bypass passage 61 flows to the first outdoor heat exchange unit 46a.

  The low-pressure refrigerant evaporates by exchanging heat with outdoor air in the second outdoor heat exchange section 46b. The high-temperature and high-pressure refrigerant dissipates heat in the first outdoor heat exchange unit 46a and melts frost attached to the surface of the first outdoor heat exchange unit 46a. The refrigerant evaporated in the second outdoor heat exchanging part 46b and the refrigerant dissipated in the first outdoor heat exchanging part 46a merge at the outlet of the outdoor heat exchanger 46, and again enter the compressor 5 through the four-way switching valve 2. Inhaled.

  Since the frost naturally melts when the outdoor temperature is not below freezing point, the control unit 8 closes the on-off valve 71 when the detected temperature of the outdoor temperature sensor 91 is equal to or higher than a predetermined value (preferably 5 ° C or higher). Perform defrosting operation without introducing high-pressure / high-temperature refrigerant.

(4-4) Refrigerant Flow When Compressor Starts Here, the refrigerant flow when the compressor is started will be described with reference to FIGS. 1 and 9D. In FIG. 1, the control unit 8 switches the four-way switching valve 2 to a heating operation path (indicated by a solid line), connects the discharge side of the compressor 5 and the gas side of the indoor heat exchanger 40, and the compressor 5. Are connected to the gas side of the outdoor heat exchanger 46. Further, the control unit 8 closes the expansion valve 7, opens the on-off valve 71, opens the second expansion valve 40c to an opening that is not intended to be fully opened or depressurized, and the flow path switching valve 51 is a fourth mode shown in FIG. 9D. Switch to.

  Under the above conditions, the refrigerant is sucked into the compressor 5 and is discharged after being compressed to a high pressure. Since the expansion valve 7 is closed, the refrigerant does not flow through the path from the four-way switching valve 2 to the expansion valve 7 via the indoor heat exchanger 40. On the other hand, since the bypass passage 61 is branched from the middle of the pipe connecting the compressor 5 and the four-way switching valve 2, the refrigerant discharged from the compressor 5 enters the bypass passage 61. Since the on-off valve 71 is open, the refrigerant flows through the bypass passage 61. Since the flow path switching valve 51 is switched to the fourth configuration, the fourth pipe connection part 14 and the second pipe connection part 12 communicate with each other. Therefore, the refrigerant that has entered from the bypass passage 61 flows into the second bypass passage 62. The refrigerant flowing through the second bypass passage 62 is again sucked into the compressor 5 through the four-way switching valve 2.

  In general, when the outside air temperature is low, the compressor 5 immediately before the start of the heating operation is cooled, the heat capacity of the compressor 5 is large, and the high temperature refrigerant circulates in the indoor heat exchanger 40 after the heating operation is started. It takes a certain time to become. Therefore, from the viewpoint of heating operation performance, it is preferable to quickly increase the compressor temperature by the above control.

(4-5) Refrigerant Flow During Reheat Dehumidification Operation Here, the refrigerant flow during the reheat dehumidification operation will be described with reference to FIGS. 1 and 9E. In FIG. 1, the control unit 8 switches the four-way switching valve 2 to a cooling operation path (indicated by a dotted line), connects the discharge side of the compressor 5 and the gas side of the outdoor heat exchanger 46, and the compressor 5. And the gas side of the indoor heat exchanger 40 are connected.

  Furthermore, the control unit 8 sets the opening of the expansion valve 7 to an opening that is not fully opened or depressurized, closes the on-off valve 71, and throttles the opening of the second expansion valve 40c to such an extent that the refrigerant is depressurized. Further, the flow path switching valve 51 is switched to the fifth mode shown in FIG. 9E.

  Under the above conditions, the refrigerant is sucked into the compressor 5 and is discharged after being compressed to a high pressure. The high-pressure refrigerant discharged from the compressor 5 is sent to the outdoor heat exchanger 46 through the four-way switching valve 2. In addition, since the bypass path 61 is branched from the middle of the pipe connecting the compressor 5 and the four-way switching valve 2, a part of the refrigerant discharged from the compressor 5 tends to flow into the bypass path 61. Since the on-off valve 71 is closed, the refrigerant does not flow through the bypass passage 61.

  The refrigerant is split at the inlet of the outdoor heat exchanger 46 into a refrigerant that enters the first outdoor heat exchange unit 46 a, a refrigerant that enters the second outdoor heat exchange unit 46 b, and a refrigerant that flows to the second bypass path 62. However, since each of the first outdoor heat exchange section 46a and the second outdoor heat exchange section 46b has a larger flow resistance than the second bypass path 62, most of the refrigerant switches the flow path through the second bypass path 62. It goes to the second pipe connection part 12 of the valve 51.

  Since the flow path switching valve 51 is switched to the fifth mode, the second pipe connection part 12 and the first pipe connection part 11 communicate with each other. The refrigerant that has flowed into the second pipe connection part 12 reaches the expansion valve 7 through the first pipe connection part 11. Since the opening degree of the expansion valve 7 is an opening degree that is not intended to be fully opened or depressurized, the refrigerant enters the first indoor heat exchanger 40a of the indoor heat exchanger 40 without being depressurized by the expansion valve 7.

  In the indoor heat exchanger 40, the refrigerant is decompressed by the second expansion valve 40c between the first indoor heat exchange unit 40a and the second indoor heat exchange unit 40b, so that the first indoor heat exchange unit 40a is a condenser. As a result, the second indoor heat exchange unit 40b functions as an evaporator.

  That is, the refrigerant exchanges heat with the indoor air in the first indoor heat exchange unit 40a and condenses, and evaporates by exchanging with the indoor air in the second indoor heat exchange unit 40b. The low-pressure refrigerant evaporated in the second indoor heat exchange unit 40b is again sucked into the compressor 5 through the four-way switching valve 2.

  Here, when the outdoor heat exchanger 46 does not function as a condenser and only the first indoor heat exchange part 40a of the indoor heat exchanger 40 functions as a condenser, surplus refrigerant is generated. Because the required amount of refrigerant is set on the assumption that the outdoor heat exchanger 46 functions as a condenser, the first indoor heat exchanger 40a having a smaller capacity than the outdoor heat exchanger 40 is used as a condenser. This is because, when the function is performed, it is not possible to store the refrigerant corresponding to the capacity difference between the outdoor heat exchanger 46 and the first indoor heat exchange unit 40a. If the surplus refrigerant flows into the first indoor heat exchanging portion 40a, the high pressure increases and the load on the compressor 5 increases, which increases the energy consumption of the compressor 5 and is not preferable.

  However, in this air conditioner 300, since the inlet of the outdoor heat exchanger 46 is open, excess refrigerant is stored in the outdoor heat exchanger 46. Therefore, an increase in the load on the compressor 5 is avoided.

(5) Features (5-1)
In the air conditioner 300, the flow path switching valve 51 has a switching mechanism for switching to one of the first form, the second form, and the third form. The first form is a form in which the refrigerant that has entered from the expansion valve 7 flows through both the first outdoor heat exchange unit 46a and the second outdoor heat exchange unit 46b. The second form is a form in which the refrigerant that has entered from the expansion valve 7 is caused to flow to the first outdoor heat exchange part 46a, and the refrigerant that has entered from the bypass passage 61 is caused to flow to the second outdoor heat exchange part 46b. A 3rd form is a form which flows the refrigerant | coolant which entered from the expansion valve 7 to the 2nd outdoor heat exchange part 46b, and flows the refrigerant | coolant which entered from the bypass path 61 to the 1st outdoor heat exchange part 46a. When performing the defrosting operation, the controller 8 switches the flow path switching valve 51 to the second form or the third form, and opens the on-off valve 71 of the bypass passage 61. The on-off valve 71 is disposed in the bypass passage 61, and when the on-off valve 71 is open, a part of the refrigerant discharged from the compressor 5 flows toward the passage switching valve 51 in the bypass passage 61.

  As a result, in the air conditioner 300, the heating operation is continued by using one of the first outdoor heat exchange unit 46a and the second outdoor heat exchange unit 46b of the outdoor heat exchanger 46, while the bypass passage 61 is provided on the other side. The high-pressure and high-temperature refrigerant can be introduced through the defrosting. Therefore, defrosting is performed without stopping the warm air supply.

(5-2)
In the air conditioner 300, the control unit 8 temporarily switches to the fourth mode before switching the flow path switching valve 51 to the first mode. The fourth form is a form in which the refrigerant that has entered from the bypass passage 61 flows to the second bypass passage 62. The second bypass passage 62 connects the outlet of the outdoor heat exchanger 46 and the flow path switching valve 51 during the heating operation.

  As a result, in the air conditioner 300, when the compressor for heating operation is started, a part of the high-pressure and high-temperature gas refrigerant discharged from the compressor 5 is passed through the bypass passage 61, the flow path switching valve 51, and the second bypass. Since it flows in order of the path 62 and returns to the compressor 5 again, the temperature of the compressor 5 rises rapidly.

(5-3)
In the air conditioner 300, when the control unit 8 performs the reheat dehumidifying operation, the flow path switching valve 51 is switched to the fifth mode. The fifth form is a form in which the refrigerant that has entered from the second bypass passage 62 flows to the expansion valve 7.

  As a result, surplus refrigerant generated during the reheat dehumidification operation is stored in the outdoor heat exchanger 46. Therefore, it is avoided that the refrigerating and dehumidifying operation is hindered by the excess refrigerant.

  As described above, according to the present invention, since the defrosting operation can be performed while continuing the heating operation, it is useful for a refrigeration apparatus using a vapor compression refrigeration cycle.

5 Compressor 7 Expansion valve (pressure reducer)
8 Control unit 10 Main body 20 Valve body (movable member)
40 indoor heat exchanger 40a first indoor heat exchange part 40b second indoor heat exchange part 40c second expansion valve (decompression part)
46 outdoor heat exchanger 46a 1st outdoor heat exchange part 46b 2nd outdoor heat exchange part 51 Flow path switching valve 61 Bypass path 62 Second bypass path 91 Outdoor temperature sensor 300 Air conditioner

JP-A-11-132603

Claims (4)

An air conditioner using a vapor compression refrigeration cycle in which refrigerant circulates in the order of a compressor (5), a condenser, a decompressor (7), and an evaporator,
An indoor heat exchanger (40) that becomes the condenser during heating operation and the evaporator during cooling operation;
An outdoor heat exchanger (46) that serves as the evaporator during heating operation and serves as the condenser during cooling operation;
A flow path switching valve (51) disposed between the pressure reducer (7) and the outdoor heat exchanger (46);
A bypass path (61) for guiding a part of refrigerant discharged from the compressor (5) to the flow path switching valve (51);
An on-off valve (71) disposed in the bypass passage (61);
A control unit (8) for controlling at least the flow path switching valve (51) and the on-off valve (71);
With
The outdoor heat exchanger (46)
A first outdoor heat exchange section (46a) and a second outdoor heat exchange section (46b) connected in parallel with the first outdoor heat exchange section (46a),
Have
The flow path switching valve (51)
A planar first valve seat (201) provided with a plurality of ports is provided, and the pressure reducer (7), the first outdoor heat exchange section (46a), and the second outdoor heat are passed through the ports. A first valve chamber (101) capable of communicating with the exchange part (46b);
A second valve chamber (102) having a planar second valve seat (202) provided with a plurality of ports, and communicating with at least the bypass passage (61) via the ports;
The first valve chamber (101) and the second valve chamber (102) are partitioned, and one end is close to the first valve seat (201) and the other end is close to the second valve seat (202). A valve body (20) having a tube (200);
A drive unit (30) for rotating the valve body (20);
Including
Furthermore, the flow path switching valve (51)
Since one end of the flow pipe (200) does not face any of the ports of the first valve seat (201), the refrigerant that has entered from the pressure reducer (7) is transferred to the first outdoor heat exchanger (46a). And a first mode that flows to both of the second outdoor heat exchange section (46b),
One end of the flow pipe (200) faces the port of the first valve seat (201) communicating with the second outdoor heat exchange part (46b), and the other end communicates with the bypass path (61). By facing the port of the two-valve seat (202), the refrigerant entered from the pressure reducer (7) flows into the first outdoor heat exchange section (46a) and enters the bypass path (61). In the second outdoor heat exchange section (46b), and
One end of the flow pipe (200) faces the port of the first valve seat (201) communicating with the first outdoor heat exchange part (46a), and the other end communicates with the bypass path (61). By facing the port of the two-valve seat (202), the refrigerant entered from the pressure reducer (7) flows into the second outdoor heat exchange section (46b) and enters the bypass passage (61). A third mode in which the air flows through the first outdoor heat exchange section (46a),
Switch to one of the
When performing the defrosting operation, the control unit (8) switches the flow path switching valve (51) to the second form or the third form, and opens the on-off valve (71).
Air conditioner. An outdoor temperature sensor (91) for detecting the outdoor temperature;
The controller (8) closes the on-off valve (71) when the temperature detected by the outdoor temperature sensor (91) is equal to or higher than a predetermined temperature.
The air conditioner according to claim 2. A second bypass (62) connecting the outlet of the outdoor heat exchanger (46) during heating operation and the one port of the second valve chamber (102);
The flow path switching valve (51)
The first form,
Said second form,
The third form, and
Since the end of the flow pipe (200) does not face any port of the second valve seat (202), the refrigerant that has entered from the bypass path (61) flows into the second bypass path (62). 4th form,
It is possible to switch to either
The controller (8) switches to the fourth mode before switching the flow path switching valve (51) to the first mode.
The air conditioner according to claim 2. The indoor heat exchanger (40)
A first indoor heat exchange section (40a);
A second indoor heat exchange section (40b);
A decompression section (40c) connected between the first indoor heat exchange section (40a) and the second indoor heat exchange section (40b);
Have
The flow path switching valve (51)
The first form,
Said second form,
The third form,
The fourth form, and
The second valve with one end of the flow pipe (200) facing the port of the first valve seat (201) leading to the pressure reducer (7) and the other end leading to the second bypass passage (62) A fifth mode in which the refrigerant entering from the second bypass passage (62) flows to the decompressor (7) by facing the port of the seat (202);
It is possible to switch to either
The controller (8) performs the reheat dehumidification operation in which the refrigerant discharged from the compressor (5) through the cycle opposite to that during the heating operation is caused to flow to the first indoor heat exchange unit (40a). Switching the flow path switching valve (51) to the fifth configuration;
The air conditioner according to claim 4.

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