JP2012127542A - Air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely defrost an outdoor heat exchanger while continuing the heating function.SOLUTION: An air conditioning device includes: a first four-way valve 7 arranged on a gas pipe L41; a first connection pipe 8 connecting the first four-way valve 7 with a suction pipe L21; a temperature sensor 9 detecting temperature in the inside of the outdoor heat exchanger; bypass piping 11 connecting a liquid pipe L42 with the suction pipe L21; an auxiliary heat exchanger 12 exchanging heat between the refrigerant flowing in the liquid pipe L42 and the refrigerant flowing in the bypass piping 11; and an auxiliary expansion valve 13 provided on the bypass piping 11. During heating operation, when the detected temperature of the temperature sensor 9 is not larger than a predetermined value, while a main four-way valve 3 is maintained in a heating circuit, the first four-way valve 7 is switched to a cooling circuit to let a gas refrigerant flow in the outdoor heat exchanger 4, and by opening the auxiliary expansion valve 13, a liquid refrigerant is evaporated by the auxiliary heat exchanger 12 and is returned to the suction pipe L21 as the gas refrigerant.

Description

  The present invention relates to an air conditioner having a defrosting function.

  Conventionally, an air conditioner having a defrosting function is configured to periodically perform a defrosting operation during heating operation. This defrosting operation is performed by switching the four-way valve to which the gas pipe of the outdoor heat exchanger is connected, and there is a problem that the heating operation cannot be performed during the defrosting operation.

  Here, as shown in Patent Document 1, the outdoor heat exchanger is divided into two parts, a first heat exchanger and a second heat exchanger, and each gas pipe is provided with a first four-way valve and a second four-way valve, By switching these four-way valves, it has been considered that one defrosting operation can be performed with the other outdoor heat exchanger while heating operation is performed with the other outdoor heat exchanger. By repeating this switching operation, defrosting can be performed without stopping the heating operation, and comfort can be improved.

  However, when the divided heat exchange has a vertically installed structure, there is a problem that the defrost water of the upper heat exchanger freezes at the boundary of the upper and lower heat exchangers, and the heating capacity is reduced. Thus, even when the outdoor heat exchanger is divided into upper and lower parts, there is a problem that frost still adheres to the outdoor heat exchanger and the heat exchange function is impaired and the heating capacity is reduced.

JP 59-18025 A

  Therefore, the present invention has been made to solve the above-mentioned problems all at once, and a main intended problem is to surely defrost the outdoor heat exchanger while continuing the heating function.

  That is, the air conditioner according to the present invention is an air conditioner having a refrigerant circuit formed by annularly connecting a compressor, a main four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger, and the outdoor heat A first four-way valve disposed in a gas pipe of the exchanger; a first connection pipe connecting the first four-way valve and the suction pipe of the compressor; and a temperature sensor for detecting a temperature inside the outdoor heat exchanger. And a bypass pipe connecting the liquid pipe of the outdoor heat exchanger and the suction pipe of the compressor, and an auxiliary unit provided in the bypass pipe for exchanging heat between the refrigerant flowing through the liquid pipe and the refrigerant flowing through the bypass pipe A heat exchanger; and a control device that controls the main four-way valve, the first four-way valve, and the auxiliary expansion valve, and the control device detects a temperature detected by the temperature sensor at a predetermined value or less during heating operation. The main four-way valve is used as a heating circuit. In this state, the first four-way valve is switched to a cooling circuit so that the gas refrigerant flows through the outdoor heat exchanger, the auxiliary expansion valve is opened, and the liquid refrigerant is evaporated by the auxiliary heat exchanger. And returning to the suction pipe.

  If this is the case, it is possible to flow the high-temperature gas refrigerant to the outdoor heat exchanger by switching the outdoor heat exchanger to the cooling circuit with the first four-way valve while maintaining the heating circuit with the main four-way valve. Frost adhering to the outdoor heat exchanger can be removed. At this time, the auxiliary expansion valve provided in the bypass pipe is opened, and at least a part of the liquid refrigerant is evaporated by the auxiliary heat exchanger and returned to the suction pipe as a gas refrigerant. By making it an evaporator, a decrease in suction pressure can be prevented, defrosting can be performed while continuing heating operation, and a decrease in room temperature during defrosting can be suppressed to improve comfort.

  The outdoor heat exchanger is divided into a first outdoor heat exchanger and a second outdoor heat exchanger, and a first four-way valve disposed in a gas pipe of the first outdoor heat exchanger; A first connecting pipe for connecting the first four-way valve and the suction pipe of the compressor; a first temperature sensor for detecting a temperature inside the first outdoor heat exchanger; and a liquid pipe for the first outdoor heat exchanger. A first expansion valve provided in the second outdoor valve, a second four-way valve disposed in a gas pipe of the second outdoor heat exchanger, and a second connection pipe connecting the second four-way valve and the suction pipe of the compressor A second temperature sensor for detecting a temperature inside the second outdoor heat exchanger, and a second expansion valve provided in a liquid pipe of the second outdoor heat exchanger, and the control device includes the first Only one outdoor heat exchanger is defrosted, then the first outdoor heat exchanger and the second outdoor heat exchanger are simultaneously defrosted, and then the second outdoor Only the exchanger is defrosted, and when the first outdoor heat exchanger and the second outdoor heat exchanger are simultaneously defrosted, the auxiliary expansion valve is opened and the auxiliary heat exchanger is used as a liquid refrigerant. It is desirable that the gas is evaporated and returned to the suction pipe as a gas refrigerant.

  In this way, by alternately defrosting the first outdoor heat exchanger and the second outdoor heat exchanger, heating operation can be continued even during defrosting, so that a decrease in room temperature during defrosting is suppressed and comfort is improved. it can. Also, the first outdoor heat exchange is performed by simultaneously defrosting between the defrosting of the first outdoor heat exchanger and the defrosting of the second outdoor heat exchanger to simultaneously increase the temperature of the pipes of both heat exchangers. It is possible to prevent the defrost water of the refrigerator from freezing at the heat exchanger boundary.

  As a specific control mode of the control device, when the control device detects that the temperature detected by the first temperature sensor or the second temperature sensor is a predetermined value or less during heating operation, the main four-way valve is In the state maintained in the heating circuit, the first four-way valve is switched to the cooling circuit and the second four-way valve is maintained in the heating circuit so that the gas refrigerant flows through the first outdoor heat exchanger, and then the second The four-way valve and the second four-way valve are simultaneously switched to the cooling circuit, and a gas refrigerant is allowed to flow to the first outdoor heat exchanger and the second outdoor heat exchanger for a predetermined time, and the auxiliary expansion valve is opened to The liquid refrigerant is evaporated by the auxiliary heat exchanger and returned to the suction pipe as a gas refrigerant, and then the first four-way valve is switched to the heating circuit, and the second four-way valve is maintained in the cooling circuit, 2 Flowing gas refrigerant through outdoor heat exchanger The in it is desirable.

  Immediately after switching to the first four-way valve that has started defrosting, the high-temperature gas refrigerant flows into the first outdoor heat exchanger all at once, so that the temperature detected by the first temperature sensor rises rapidly. For this reason, it is desirable that the control device acquires the detected temperature of the first temperature sensor after a predetermined time has elapsed after the start of defrosting of the first outdoor heat exchanger. That is, the detection of the initial temperature rise can be avoided by delaying the detection start of the first temperature sensor for a predetermined time. Thereby, the false detection of the completion | finish of defrost can be prevented, and the heating capacity fall can be prevented by preventing a residual frost.

  The outdoor heat exchanger is divided into a first outdoor heat exchanger and a second outdoor heat exchanger and is divided into upper and lower parts, and a high temperature is applied to the division boundary between the first heat exchanger and the second heat exchanger during defrosting. It is desirable that the path pipe is formed so that the refrigerant gas flows. Thereby, the temperature of the refrigerant flowing in the boundary path piping of the upper and lower outdoor heat exchangers can be kept high, the defrost water of the first outdoor heat exchanger can be prevented from freezing at the boundary of the heat exchanger, and heating by freezing Capability reduction can be prevented.

  According to this invention comprised in this way, an outdoor heat exchanger can be defrosted reliably, continuing a heating function.

The schematic diagram which shows the structure of the outdoor unit of the air conditioning apparatus which concerns on 1st Embodiment. The schematic diagram which shows the structure of the outdoor unit of the air conditioning apparatus which concerns on 2nd Embodiment. The figure which shows the defrost operation of the 1st, 2nd outdoor heat exchanger in 2nd Embodiment. The figure which shows the time change of the detected temperature of a 1st temperature sensor. The schematic diagram which shows the structure of the path piping of a 1st, 2nd outdoor heat exchanger.

  An embodiment of the present invention will be described below with reference to the drawings.

<First Embodiment>
As shown in FIG. 1, the air conditioner 100 according to the present embodiment is a refrigerant formed by connecting a compressor 2, a main four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, and an indoor heat exchanger 6 in an annular shape. An air conditioner having a circuit. The main four-way valve 3 changes the refrigerant flow and selects the outdoor heat exchanger 4 and the indoor heat exchanger 6 respectively disposed in the indoor unit 1a and the outdoor unit 1b as either a condenser or an evaporator. Switching between the air conditioning and heating in the room.

  The air conditioner 100 also includes a first four-way valve 7 disposed in the gas pipe L41 of the outdoor heat exchanger 4, and a first connection pipe that connects the first four-way valve 7 and the suction pipe L21 of the compressor 2. 8, a temperature sensor 9 that detects the temperature of the path pipe below the outdoor heat exchanger 4, an expansion valve 10 that is provided in the liquid pipe L 42 of the outdoor heat exchanger 4 and serves as a flow rate adjustment valve that adjusts the refrigerant flow rate, A bypass pipe 11 that connects the liquid pipe L42 of the outdoor heat exchanger 4 and the suction pipe L21 of the compressor 2; a refrigerant that is provided in the bypass pipe 11 and that flows through the liquid pipe L42 and a refrigerant that flows through the bypass pipe 11 An auxiliary heat exchanger 12 that performs heat exchange, an auxiliary expansion valve 13 that is provided on the liquid pipe L42 side with respect to the auxiliary heat exchanger 12 in the bypass pipe 11, a main four-way valve 3, and a first four-way valve 7 and the control for controlling the auxiliary expansion valve 13 etc. Comprising a device 14. The expansion valve 10 and the auxiliary expansion valve 13 are electronic expansion valves.

  The control device 14 is a so-called computer having a CPU, a memory, an I / O channel, an output device such as a display, an input device such as a keyboard, an AD converter, and the like, and the CPU and its peripheral devices according to a program stored in the memory. Controls each part of the air conditioning apparatus 100.

  Specifically, when the temperature detected by the temperature sensor 9 is equal to or lower than a predetermined value during the heating operation, the control device 14 sets the first four-way valve 7 to the cooling circuit while maintaining the main four-way valve 3 in the heating circuit. In addition, the gas refrigerant flows through the outdoor heat exchanger 4 and the auxiliary expansion valve 13 serving as an on-off valve is opened to evaporate the liquid refrigerant by the auxiliary heat exchanger 12 and return it to the suction pipe L21 as a gas refrigerant. .

  Thus, in a state where the main four-way valve 3 maintains the heating circuit by the control device 14, the high-temperature gas refrigerant that has exited the discharge pipe L <b> 22 of the compressor 2 flows to the indoor heat exchanger 6 through the main four-way valve 3. Then, the liquid refrigerant that has passed through the indoor heat exchanger 6 flows into the liquid pipe L42 connected to the outdoor heat exchanger 4.

  On the other hand, in a state where the first four-way valve 7 is switched to the cooling circuit, the high-temperature gas refrigerant that has exited the discharge pipe L22 of the compressor 2 passes through the gas pipe L41 of the heat exchanger 4 connected to the discharge pipe L22. And flows into the outdoor heat exchanger 4 through the first four-way valve 7. As a result, the high-temperature gas refrigerant can pass through the outdoor heat exchanger 4 and melt and remove the frost attached to the outdoor heat exchanger 4. Then, the refrigerant that has passed through the outdoor heat exchanger 4 flows into the liquid pipe L42.

  The liquid refrigerant that has passed through the indoor heat exchanger 6 flows into the auxiliary heat exchanger 12 through the bypass pipe 11 from the liquid pipe L42. On the other hand, the liquid refrigerant that has passed through the outdoor heat exchanger 4 flows into the auxiliary heat exchanger 12 through the liquid pipe L42. A part of the liquid refrigerant flowing into the auxiliary heat exchanger 12 through the bypass pipe 11 evaporates and flows into the suction pipe L21 as a gas refrigerant.

  And the control apparatus 14 switches the 1st four-way valve 7 to a heating circuit, and is set as normal heating operation, when the detected temperature of the temperature sensor 9 becomes more than predetermined value (for example, 1 degreeC or more). Note that the auxiliary expansion valve 13 is closed during normal heating operation other than during the above defrosting operation.

<Effects of First Embodiment>
According to the air conditioner 100 according to the first embodiment configured as described above, the outdoor heat exchanger 4 is switched to the cooling circuit by the first four-way valve 7 while the heating circuit is maintained by the main four-way valve 3, and the outdoor Since the high-temperature gas refrigerant can flow through the heat exchanger 4, frost attached to the outdoor heat exchanger 4 can be removed.

  At this time, the auxiliary expansion valve 13 provided in the bypass pipe 11 is opened, and at least a part of the liquid refrigerant is evaporated by the auxiliary heat exchanger 12 and returned to the suction pipe L21 as a gas refrigerant. By using the heat exchanger 12 as an evaporator, a reduction in suction pressure can be prevented and defrosting can be performed while continuing the heating operation, and a decrease in room temperature during defrosting can be suppressed and comfort can be improved.

Second Embodiment
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member corresponding to the said 1st Embodiment.
As shown in FIG. 2, the air conditioner 100 according to the present embodiment is a refrigerant formed by annularly connecting a compressor 2, a main four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, and an indoor heat exchanger 6. In the air conditioner having a circuit, the outdoor heat exchanger 4 is divided into a first outdoor heat exchanger 4A and a second outdoor heat exchanger 4B.

  The air conditioner 100 connects the first four-way valve 71 disposed in the gas pipe L41A of the first outdoor heat exchanger 4A, the first four-way valve 71, and the suction pipe L21 of the compressor 2. A first temperature sensor 91 for detecting the temperature of the connecting pipe 81, the temperature of the path pipe inside the first outdoor heat exchanger 4A, and the liquid pipe L42A of the first outdoor heat exchanger 4A, and a first for adjusting the refrigerant flow rate. An expansion valve 101; a second four-way valve 72 disposed in a gas pipe L41B of the second outdoor heat exchanger 4B; a second connection pipe 82 that connects the second four-way valve 72 and the suction pipe L21 of the compressor 2; A second temperature sensor 92 that detects the temperature inside the second outdoor heat exchanger 4B, and a second expansion valve 102 that is provided in the liquid pipe L42B of the second outdoor heat exchanger 4B and adjusts the refrigerant flow rate. Yes. In the present embodiment, electronic expansion valves are used for the first expansion valve 101 and the second expansion valve 102.

  Further, the air conditioner 100 includes a bypass pipe 11 that connects the liquid pipe L42A of the first outdoor heat exchanger 4A and the junction pipe L42 of the liquid pipe L42B of the second outdoor heat exchanger 4B and the suction pipe L21 of the compressor 2. And the auxiliary heat exchanger 12 provided in the bypass pipe 11 for exchanging heat between the refrigerant flowing through the liquid pipe L42 and the refrigerant flowing through the bypass pipe 11, and on the liquid pipe L42 side of the auxiliary heat exchanger 12 in the bypass pipe 11 And an auxiliary expansion valve 13 that depressurizes the refrigerant, and a control device 14 that controls the main four-way valve 3, the first and second four-way valves 71 and 72, the first and second expansion valves 101 and 102, and the like. .

  Therefore, the controller 14 defrosts only the first outdoor heat exchanger 4A, and then the first outdoor heat exchanger 4A and the second outdoor, as shown in FIG. The heat exchanger 4B is defrosted simultaneously, and then only the second outdoor heat exchanger 4B is defrosted. Here, the control device 14 opens the auxiliary expansion valve 13 and evaporates the liquid refrigerant by the auxiliary heat exchanger 12 when the first outdoor heat exchanger 4A and the second outdoor heat exchanger 4B are simultaneously defrosted. The gas refrigerant is returned to the suction pipe L21.

  Specifically, when the temperature detected by the first temperature sensor 91 or the second temperature sensor 92 is not more than a predetermined value during the heating operation, the control device 14 first maintains the main four-way valve 3 in the heating circuit. The first four-way valve 71 is switched to the cooling circuit, and the second four-way valve 72 is maintained in the heating circuit, so that the gas refrigerant flows through the first outdoor heat exchanger 4A. As a result, the high temperature gas refrigerant is caused to flow through the first outdoor heat exchanger 4A to defrost the first outdoor heat exchanger 4A. The defrosting operation of the first outdoor heat exchanger 4A ends when the temperature detected by the first temperature sensor 91 is equal to or higher than a predetermined value (for example, 1 ° C. or higher). Note that the auxiliary expansion valve 13 is closed during the defrosting operation of only the first outdoor heat exchanger 4A.

  Here, the control device 14 acquires the detected temperature of the first temperature sensor 91 with a delay after a predetermined time has elapsed after the start of defrosting of the first outdoor heat exchanger 4A. Immediately after the switching of the first four-way valve 71 that has started defrosting, high-temperature gas refrigerant flows into the first outdoor heat exchanger 4A all at once, so that the temperature detected by the first temperature sensor 91 temporarily changes as shown in FIG. Soars. By delaying the detection start of the first temperature sensor 91 for a predetermined time (for example, 60 seconds), the detection of the initial temperature rise is avoided.

  Next, the control device 14 switches the first four-way valve 71 and the second four-way valve 72 to the cooling circuit at the same time, and for the predetermined time T (for example, 30 seconds), the first outdoor heat exchanger 4A and the second outdoor heat exchanger. While flowing the high-temperature gas refrigerant to 4B, the auxiliary expansion valve 13 is opened for a predetermined time T (for example, 30 seconds), the liquid refrigerant is evaporated by the auxiliary heat exchanger 12, and returned to the suction pipe L21 as a gas refrigerant.

  Next, the control device 14 switches the first four-way valve 71 to the heating circuit, maintains the second four-way valve 72 in the cooling circuit, and flows the gas refrigerant to the second outdoor heat exchanger 4B. Thereby, a high-temperature gas refrigerant is flowed into the 2nd outdoor heat exchanger 4B, and the 2nd outdoor heat exchanger 4B is defrosted. The defrosting operation of the second outdoor heat exchanger 4B is terminated when the temperature detected by the second temperature sensor 92 is equal to or higher than a predetermined value (for example, 1 ° C. or higher), and the second four-way valve 72 is switched to the heating circuit. Normal heating operation. Note that the auxiliary expansion valve 13 is closed during the defrosting operation of only the second outdoor heat exchanger 4B.

<Effects of Second Embodiment>
According to the air conditioner 100 according to the second embodiment configured as described above, the heating operation is performed even during the defrosting by alternately defrosting the first outdoor heat exchanger 4A and the second outdoor heat exchanger 4B. Since it can continue, the fall of the room temperature during a defrost can be suppressed and comfort can be improved.

  In addition, by simultaneously defrosting between the defrosting of the first outdoor heat exchanger 4A and the defrosting of the second outdoor heat exchanger 4B and simultaneously increasing the path piping temperature of both the heat exchangers 4A and 4B, It is possible to prevent the defrost water of the first outdoor heat exchanger 4A from freezing at the heat exchanger boundary. At this time, by using the auxiliary heat exchanger 12 as an evaporator, it is possible to prevent a reduction in suction pressure and to perform defrosting while continuing the heating operation, and it is possible to improve comfort by suppressing a decrease in room temperature during the defrosting.

<Other modified embodiments>
The present invention is not limited to the above embodiment.
For example, in the second embodiment, a path pipe may be formed so that the high-temperature refrigerant gas flows through the division boundary between the first outdoor heat exchanger 4A and the second outdoor heat exchanger 4B during defrosting. Specifically, as shown in FIG. 5, in the path piping of the first outdoor heat exchanger 4A and the path piping of the second outdoor heat exchanger 4B, the piping into which the liquid refrigerant flows is separated as much as possible from the division boundary. At the same time, the pipes through which the refrigerant flowing through the path pipe and having a high temperature flow are brought close to each other at the division boundary. Thereby, the temperature of the refrigerant flowing in the boundary path piping of the upper and lower outdoor heat exchangers 4A and 4B can be kept high, and the defrost water of the first outdoor heat exchanger 4A can be prevented from freezing at the heat exchanger boundary. The heating capacity can be prevented from lowering due to freezing.

  In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Air conditioning apparatus 2 ... Compressor L21 ... Intake pipe 3 ... Main four-way valve 4 ... Outdoor heat exchanger L41 ... Outdoor heat exchanger gas pipe L42 ... Outdoor Heat exchanger liquid pipe 5 ... expansion valve 6 ... indoor heat exchanger 7 ... first four-way valve 8 ... first connecting pipe 9 ... temperature sensor 11 ... bypass pipe 12 ..Auxiliary heat exchanger 13 ・ ・ ・ Auxiliary expansion valve 14 ・ ・ ・ Control device

Claims (5)

An air conditioner having a refrigerant circuit formed by annularly connecting a compressor, a main four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger,
A first four-way valve disposed in a gas pipe of the outdoor heat exchanger;
A first connecting pipe connecting the first four-way valve and the suction pipe of the compressor;
A temperature sensor for detecting the temperature inside the outdoor heat exchanger;
A bypass pipe connecting the liquid pipe of the outdoor heat exchanger and the suction pipe of the compressor;
An auxiliary heat exchanger provided in the bypass pipe for exchanging heat between the refrigerant flowing through the liquid pipe and the refrigerant flowing through the bypass pipe;
An auxiliary expansion valve provided on the liquid pipe side of the auxiliary heat exchanger in the bypass pipe;
A control device for controlling the main four-way valve, the first four-way valve and the auxiliary expansion valve;
In the heating operation, when the detected temperature of the temperature sensor is equal to or lower than a predetermined value, the control device switches the first four-way valve to the cooling circuit while maintaining the main four-way valve in the heating circuit. An air conditioner that causes gas refrigerant to flow through an outdoor heat exchanger, opens the auxiliary expansion valve, evaporates liquid refrigerant by the auxiliary heat exchanger, and returns the liquid refrigerant to the suction pipe as a gas refrigerant. The outdoor heat exchanger is divided into a first outdoor heat exchanger and a second outdoor heat exchanger and is divided into upper and lower parts,
A first four-way valve disposed in a gas pipe of the first outdoor heat exchanger;
A first connecting pipe connecting the first four-way valve and the suction pipe of the compressor;
A first temperature sensor for detecting a temperature inside the first outdoor heat exchanger;
A first expansion valve provided in a liquid pipe of the first outdoor heat exchanger;
A second four-way valve disposed in a gas pipe of the second outdoor heat exchanger;
A second connecting pipe connecting the second four-way valve and the suction pipe of the compressor;
A second temperature sensor for detecting a temperature inside the second outdoor heat exchanger;
A second expansion valve provided in a liquid pipe of the second outdoor heat exchanger,
The controller defrosts only the first outdoor heat exchanger, then simultaneously defrosts the first outdoor heat exchanger and the second outdoor heat exchanger, and then the second outdoor heat exchanger. Only defrost,
During simultaneous defrosting of the first outdoor heat exchanger and the second outdoor heat exchanger, the auxiliary expansion valve is opened and the liquid refrigerant is evaporated by the auxiliary heat exchanger to be used as gas refrigerant in the suction pipe. The air conditioner according to claim 1, wherein the air conditioner is returned. In the state where the control device maintains the main four-way valve in the heating circuit when the detected temperature of the first temperature sensor or the second temperature sensor is equal to or lower than a predetermined value during heating operation,
Switching the first four-way valve to a cooling circuit and maintaining the second four-way valve in a heating circuit, flowing a gas refrigerant through the first outdoor heat exchanger,
Next, the first four-way valve and the second four-way valve are simultaneously switched to a cooling circuit, and a gas refrigerant is allowed to flow through the first outdoor heat exchanger and the second outdoor heat exchanger for a predetermined time, and the auxiliary expansion valve The liquid refrigerant is evaporated by the auxiliary heat exchanger and returned to the suction pipe as a gas refrigerant,
3. The air conditioner according to claim 2, wherein the first four-way valve is switched to a heating circuit, the second four-way valve is maintained in a cooling circuit, and a gas refrigerant flows through the second outdoor heat exchanger. apparatus.   The air conditioning apparatus according to claim 2 or 3, wherein the control device acquires a detected temperature of the first temperature sensor after a predetermined time has elapsed after the start of defrosting of the first outdoor heat exchanger. The outdoor heat exchanger is divided into a first outdoor heat exchanger and a second outdoor heat exchanger and is divided into upper and lower parts,
The air conditioning apparatus according to claim 1, 2, 3, or 4, wherein a pipe is formed so that a high-temperature refrigerant gas flows at a boundary between the first outdoor heat exchanger and the second outdoor heat exchanger during defrosting.