WO2017145276A1

WO2017145276A1 - Air conditioning device

Info

Publication number: WO2017145276A1
Application number: PCT/JP2016/055348
Authority: WO
Inventors: 喜浩谷口; ▲高▼田　茂生; 真作楠部; 貴彦小林; 万誉篠崎
Original assignee: 三菱電機株式会社
Priority date: 2016-02-24
Filing date: 2016-02-24
Publication date: 2017-08-31
Also published as: JP6689359B2; EP3421902A1; EP3421902A4; JPWO2017145276A1; EP3421902B1

Abstract

A refrigerant cooler disposed in the refrigerant circuit of a refrigeration cycle has: a plate for radiating heat; and piping for radiating heat, through which a refrigerant flows. The piping for radiating heat has refrigerant inlet piping, refrigerant outlet piping, and at least one bend which connects the refrigerant inlet piping and the refrigerant outlet piping. A component which constitutes an electric power conversion device is in surface contact with one surface of the plate, and the piping for radiating heat is in surface contact with the other surface of the plate. A pass for a heat source-side heat exchanger is located above the portion where the refrigerant cooler and the component which constitutes the electric power conversion device are in contact with each other.

Description

Air conditioner

The present invention relates to an air conditioner using a refrigerant, and more particularly to a technique for radiating heat loss generated by components of a power conversion device that drives a compressor and a fan. In addition, in this application, an air conditioning apparatus shall also contain the other cooling-heat apparatus using a refrigerant | coolant and a compressor.

An air conditioner that performs a refrigeration cycle often uses a compressor that compresses a refrigerant and a fan that generates air to exchange heat with the outside air via a heat exchanger. An electric motor is generally used for rotationally driving the compressor and the fan, and a power converter is used to control the operation of the electric motor. Since driving of the power converter is accompanied by heat generation of components such as a power module constituting the power converter, it is necessary to cool the power converter so as not to cause an abnormally high temperature.

As a conventional cooling method, heat sinks with fins attached to a controller that encloses a power converter in an air conditioner are brought into close contact with the heat dissipation surface of the power converter component parts, and heat loss is transferred to the air for release and heat exchange. There is an air cooling method in which cooling is performed using the wind on the secondary side of the vessel. There is also a refrigerant cooling system in which a pipe for passing a refrigerant used in the refrigeration cycle and a heat radiating surface of a power converter component are brought into close contact with each other through a plate to transmit heat loss to the refrigerant.

In the above air cooling method, even when the compressor is not driven, the wind passes through the finned heat sink as long as the fan is driven. Therefore, it is possible to cool the heat generated by the power converter component that drives the fan. is there.
On the other hand, in the refrigerant cooling method, the refrigerant for cooling does not flow to the refrigerant cooler when the compressor is not driven. Therefore, for example, when the power converter that rotates the fan is driven, the power converter component may exceed the heat-resistant temperature range due to the generated heat loss. In order to cope with this, the refrigerant pipe on the heat radiation surface of the power converter component is bent outside the electrical component box so that there is no obstacle to heat radiation in the vertical direction, and no refrigerant flows Thus, there is one that promotes natural heat dissipation from the bent portion (for example, Patent Document 1).

Japanese Patent No. 5125355 (pages 5-7, FIGS. 2 and 3)

However, the configuration of Patent Document 1 radiates heat loss generated in a state where the compressor is not driven to the atmosphere through piping and plates constituting the refrigerant cooler. Therefore, it is necessary to design the piping and plate surface area in advance in consideration of the maximum heat loss and the operating environment temperature so that the generated heat loss can be sufficiently dissipated, making the configuration of the refrigerant cooler complex, increasing the size, material costs, etc. Increasing processing costs is an issue.

The present invention has been made in response to the above problems, and its main object is to use a refrigerant cooler having the simplest possible structure and the smallest possible size even when the compressor of the air conditioner is not driven. Thus, the heat generation (also referred to as loss heat) of the components of the power conversion device can be cooled.

One aspect of the air conditioner of the present invention is a refrigeration cycle in which a compressor driven by an electric motor, a use side heat exchanger, at least one expansion device, and a heat source side heat exchanger are connected by piping, and refrigerant circulates. A refrigerant circuit that performs the operation, a power converter that supplies driving force to the electric motor, and a refrigerant cooler that distributes the refrigerant flowing through the refrigerant circuit and causes the refrigerant to absorb heat from the components of the power converter The refrigerant cooler includes a heat radiating plate and a heat radiating pipe through which the refrigerant flows, and the heat radiating pipe includes a refrigerant inlet pipe, a refrigerant outlet pipe, and the refrigerant inlet pipe. At least one bent portion connecting the refrigerant outlet pipe, the component of the power converter is in surface contact with one surface of the plate, and the heat radiating pipe is on the other surface of the plate Contacted Ri, the above the contact portion between the components of the refrigerant cooler and the power converter, a path of the heat source-side heat exchanger has to be positioned, is intended.

The air conditioner described above can cool the heat generated by the components of the power converter by circulating the refrigerant used in the refrigeration cycle through the refrigerant cooler.
The components of the power converter and the refrigerant cooler are brought into surface contact so that the thermal resistance is reduced, and the pipes constituting the refrigerant cooler are provided with bent portions so that the liquid refrigerant can easily stay. Furthermore, the positional relationship between the refrigerant cooler and the heat exchanger is configured such that the path of the heat source side heat exchanger exists above the contact portion between the refrigerant cooler and the components of the power converter. For this reason, even when the compressor is not driven, the refrigerant remaining in the refrigerant cooler can be moved between the heat source side heat exchanger by natural convection. Therefore, the components of the power converter can be cooled without complicating the configuration of the refrigerant cooler and with a smaller size than the conventional one.

It is a refrigerant circuit figure of the air conditioning apparatus in Embodiment 1 of this invention. It is a figure which shows the structure of the refrigerant cooler in Embodiment 1 of this invention, (A) is the front view seen from the installation surface side of refrigerant | coolant piping, (B) is the top view which looked at (A) from the upper direction. is there. It is explanatory drawing which shows the attachment state to the outdoor unit of a refrigerant cooler. It is explanatory drawing which shows the state of the refrigerant | coolant flow between a refrigerant cooler and a heat exchanger in a compressor stop state. It is a refrigerant circuit figure of the air conditioning apparatus in Embodiment 2 of this invention. It is a refrigerant circuit figure of the air conditioning apparatus in Embodiment 3 of this invention.

Embodiment 1 FIG.
1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention. The air conditioner of Embodiment 1 includes a compressor 1, a four-way valve 2, a use side heat exchanger 3, a use side expansion device 4a, a heat source side expansion device 4b, a heat source side heat exchanger 5, and an accumulator 14 as refrigerant piping. The refrigerant circuit 17 is connected. Moreover, each

heat exchanger

3 and 5 is equipped with the

fans

3a and 5a which usually send air to each

heat exchanger

3 and 5, as shown in FIG.
In FIG. 1, the accumulator 14 is provided, but the accumulator 14 is not necessarily required in the present invention. Further, only one of the use side expansion device 4a and the heat source side expansion device 4b may be used.
Further, a refrigerant cooler 6 is arranged in the refrigerant circuit between the use side expansion device 4a and the heat source side expansion device 4b. The refrigerant cooler 6 will be described in detail later.

The compressor 1 and the

fans

3 a and 5 a are each driven by an electric motor, and these electric motors are driven by a power converter 7. The power conversion device 7 includes components such as a power semiconductor, a reactor, a coil, a cement resistor, a power relay, and a transformer that are heat sources. These heat sources generate heat loss due to switching loss, Joule heat, and iron loss. Therefore, when there is no heat radiator, it may become high temperature of 100 degreeC or more, and it may exceed the heat resistance temperature of the insulation seed | species with which a component is provided, and may be destroyed.
Hereinafter, the components of the power conversion device 7 are collectively denoted by reference numeral 8, and the compressor component of the power conversion device 7 is denoted by reference numeral 8a and the fan component is denoted by 8b. Here, the power

converter component parts

8, 8 a, 8 b are arranged on the power converter sheet metal 71. The power converter sheet metal 71 is preferably attached to the refrigerant cooler 6 via the

heat transfer members

13, 13a, 13b.

As shown in FIGS. 2A and 2B, the refrigerant cooler 6 includes a first plate 16 on the side to which the component 8 of the power converter is fixed, and a second plate 9 to which the pipe through which the refrigerant flows is fixed. It has. The pipe | tube with which the refrigerant | coolant which comprises the refrigerant | coolant cooler 6 flows is comprised by the refrigerant | coolant inlet piping 10, the refrigerant | coolant outlet piping 11, and the bending part 15 which connects them, and the shape where the bending part 15 is located in a lower end is comprised. is doing.
In addition, you may provide the

thermal radiation members

18 and 19 between the 1st plate 16 and the 2nd plate 9, and between the 1st plate 16 and the power converter device metal plate 71, respectively. Examples of the

heat radiating members

18 and 19 include a heat radiating sheet and a heat radiating grease.

The component 8 of the power converter mounted on the power converter sheet metal 71 is disposed so as to be in surface contact with the first plate 16 via the power converter sheet metal 71. Heat exchange is performed with the component 8. The heat of the first plate 16 is transferred to the second plate 9, and further the heat of the second plate 9 is transferred to the refrigerant therein through a pipe constituting the refrigerant cooler 6.

In order to improve the heat transfer efficiency, the refrigerant cooler 6 brings the second plate 9 and the pipe through which the refrigerant in the refrigerant circuit flows into contact with each other so that the thermal resistance is small. Therefore, it fixes so that the refrigerant | coolant inlet piping 10 and the refrigerant | coolant outlet piping 11 may contact the 2nd plate 9 in as many area | regions as possible. Preferably, more than half of the peripheral surfaces of the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11 are in contact with the second plate 9. Specifically, as shown in FIG. 2B, a groove is formed in the second plate 9, and the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11 are inserted into the groove.

The second plate 9 and the first plate 16 of the refrigerant cooler 6 are made of a metal having good thermal conductivity such as aluminum or copper. Similarly, the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11 constituting the refrigerant cooler 6 are made of a metal having good thermal conductivity such as aluminum and copper. In order to reduce the thermal resistance, the contact may be made by brazing or pressure welding, or through a heat radiation sheet or heat radiation grease. From the viewpoint of service, it is better to configure the second plate 9 and the first plate 16 so that they can be brought into contact with each other via a heat dissipation sheet or heat dissipation grease, which is a heat dissipation member, and removed.
The component 8 of the power converter can be cooled by bringing the surface of the component 8 of the power converter 8 that generates heat into thermal contact with the first plate 16. At this time, it is preferable that the components 8 are brought into contact with each other via a heat dissipating sheet or a heat dissipating member 19 of heat dissipating grease so that the component 8 can be removed. However, when the thermal resistance increases, the first plate 16 may be omitted, and the power converter component 8 may be directly attached to the second plate 9. By doing so, the thermal resistance can be reduced by the amount of the first plate 16 and the heat radiating member 19.
The first plate 16, the second plate 9 and the power converter sheet metal 71 constituting the refrigerant cooler 6 use a fastening member such as a screw, and if necessary, use a fixture or the like to generate vibration or external force. It is preferable to fix so that thermal contact is not lost.

Next, the shape of the piping through which the refrigerant constituting the refrigerant cooler 6 flows will be described. The example shown in FIG. 2 shows a U-shaped configuration in which the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11 are connected by one turn (bending portion). However, the number of turns of the refrigerant pipe constituting the refrigerant cooler 6 is not limited to one turn, and may be a plurality of turns such as a W shape. By increasing the number of turns, the contact area between the second plate 9 and the pipe through which the refrigerant flows can be increased, and the heat dissipation efficiency can be increased.
The purpose of providing a turn in the refrigerant pipe constituting the refrigerant cooler 6 is to make it easier for liquid refrigerant to stay when the compressor is stopped, in addition to the effect of increasing the contact area. Of course, in order to obtain the effect of increasing the contact area, the diameter of the pipe may be increased, and the second plate surface in contact with the pipe may be provided with a groove in accordance with the pipe shape. You may employ | adopt piping of the shape which can enlarge a contact area with a 2nd plate.

Next, the attachment position of the refrigerant cooler 6 will be described with reference to FIG. Since there is no mechanism for forcibly circulating the refrigerant when the compressor of the air conditioner is stopped, the liquid refrigerant stays in the refrigerant cooler 6 by gravity. Therefore, the refrigerant pipe constituting the refrigerant cooler 6 has one or more bent parts 15 at the lower end part between the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11.
In FIG. 3, the pipe constituting the refrigerant cooler 6 has a U shape having one bent portion 15 at the lower end between the refrigerant inlet pipe 10 and the refrigerant outlet pipe 11. Further, in order to retain a large amount of refrigerant, the refrigerant cooler 6 is attached so that the contact portion between the refrigerant cooler 6 and the component 8 of the power conversion device exists below the heat source side heat exchanger path. By doing so, the liquid refrigerant stays in the refrigerant cooler 6, and even if the components of the power conversion device generate heat when the compressor 1 is stopped, thermal contact with the refrigerant cooler 6 can be maintained. The heat generated by the component 8 of the power converter is transferred to the liquid refrigerant.

Further, the refrigerant pipe from the refrigerant cooler 6 to the use side heat exchanger 3 is routed as perpendicular to the ground as possible so that the refrigerant can be connected through the shortest path and the refrigerant can easily stay in the refrigerant cooler 6. It is good. However, you may provide the bending part 15 according to the structure of an outdoor unit.
In addition, heat can be efficiently and efficiently transferred as the distance between the heat source side heat exchanger 5 and the pipe end 10a of the refrigerant inlet pipe 10 connected thereto or the pipe end 11a of the refrigerant outlet pipe 11 is shorter.

Next, the heating operation of the air conditioner of Embodiment 1 will be described. The high-temperature and high-pressure refrigerant that has flowed out of the compressor 1 is condensed in the use-side heat exchanger 3, radiates heat to the use side at that time, and further, the refrigerant is brought into a low-temperature low-pressure liquid or gas-liquid two-phase state by the use-side expansion device 4a. Become. Thereafter, the refrigerant becomes low-temperature and low-pressure gas by the heat source side heat exchanger 5, passes through the accumulator 14, and returns to the compressor 1. The refrigerant cooler 6 allows the entire flow rate used in the refrigeration cycle to flow to the piping of the refrigerant cooler 6, where the component 8 of the power converter is cooled. In the cooling by the refrigerant cooler 6, by adjusting the temperature of the refrigerant flowing into the refrigerant cooler 6 on the refrigerant circuit using an electronic expansion valve, a capillary tube, a double tube, an electromagnetic valve, or a thin tube, The cooling capacity of the refrigerant cooler 6 can be adjusted. By doing in this way, lack of cooling capacity and dew condensation can be avoided.

Next, the cooling operation of the air conditioner of Embodiment 1 will be described. The high-temperature and high-pressure refrigerant that has flowed out of the compressor 1 becomes a high-pressure liquid by the heat source side heat exchanger 5 and flows to the piping of the refrigerant cooler 6 to cool the components of the power converter and to the use side heat exchanger 3 side. Sent. On the use side heat exchanger 3 side, the refrigerant becomes a low-temperature and low-pressure liquid by the use-side expansion device 4a, exchanges heat in the use-side heat exchanger 3 to become a low-temperature and low-pressure gas, and returns to the compressor 1 through the accumulator 14. The piping of the refrigerant cooler 6 passes the entire flow rate of the refrigerant used in the refrigeration cycle, and cools the component 8 of the power converter. In the cooling by the refrigerant cooler 6, by adjusting the temperature of the refrigerant flowing into the refrigerant cooler 6 on the refrigerant circuit using an electronic expansion valve, a capillary tube, a double tube, an electromagnetic valve, or a thin tube, The cooling capacity of the refrigerant cooler 6 can be adjusted. By doing in this way, lack of cooling capacity and dew condensation can be avoided.

Next, in order to explain the cooling of the refrigerant when the compressor 1 is stopped, the following three operation modes, which are one of the functions of the outdoor unit of the air conditioner, will be described. The following modes are taken as examples and are not limited to these modes. In the first embodiment, all the heat generated in a state where the compressor is not in operation can be the target of cooling.
(1) Snow sensor operation mode (2) Inverter overheat operation mode (3) Operation mode by driving a compressor connected to another system

The snow sensor operation mode (1) is a mode in which only the fan 5a for the heat source side heat exchanger 5 is driven while the compressor 1 is stopped so that the snow does not accumulate or the accumulated snow is blown away. Since the power conversion device that drives the fan 5a operates, heat loss of the component 8b of the power conversion device occurs.
In the inverter overheating operation mode (2), when the refrigerant is accumulated in the compressor 1 while the outdoor unit is stopped, the compressor 1 is heated to gasify the liquid refrigerant in the compressor 1. This is an operation in which the motor winding in the compressor 1 is energized and heated without rotating the compressor 1. Also at this time, since the power conversion device operates, heat loss of the component 8a of the power conversion device is generated.
The operation mode of driving a compressor connected to another system in (3) is, for example, a first system provided with a refrigerant cooler 6 that cools the power converter for trial operation or operation check of the air conditioner. When a compressor connected to another second system is driven using the power conversion device used in the first system, the refrigerant does not circulate in the first system where the compressor is not driven. Equipment components generate heat loss.

Next, cooling of the component 8 of the power converter that is in contact with the refrigerant cooler 6 during the operations (1) to (3) will be described with reference to FIG.
When heat loss is generated in the component 8 of the power converter, the heat loss is absorbed by the liquid refrigerant remaining in the pipe interior 31 constituting the refrigerant cooler 6 in the vicinity of the heat generating unit 30, and the absorbed heat is in a state. Change to gas. The gas refrigerant 32 rises through the center of the pipe and reaches the heat source side heat exchanger 5. In general, a plurality of fins are attached to the piping of the heat source side heat exchanger path for heat radiation, and a large area for heat radiation into the air is provided. For this reason, the heat loss can be efficiently radiated by moving the gas refrigerant into the path of the heat source side heat exchanger 5. The refrigerant that has dissipated the heat becomes liquid refrigerant 33 and repeats the natural circulation of returning to the refrigerant cooler 6 by gravity through the inner wall surface 34 of the pipe. Thereby, even in a state where the compressor 1 is stopped, it is possible to dissipate heat by moving the heat loss of the component 8 of the power converter to the heat exchanger.
In addition, when the heat loss is small, the gasified refrigerant may release the heat loss from the pipe surface before reaching the heat source side heat exchanger 5 and return to the liquid. Since it returns to the refrigerant cooler 6, continuous cooling is possible.
Further, if the fan 5a is driven to allow the wind to flow, the heat exchange capability in the heat source side heat exchanger 5 is improved, so that the gas refrigerant can be efficiently changed to the liquid refrigerant.
Furthermore, when the component 8 of the power conversion device is generating heat by driving the fan 5a, the heat source side heat exchanger 5 is in a forced air cooling state, so that the lost heat is more efficiently transferred to the outside air. Has the effect of releasing. These effects can also be obtained in embodiments described later.

Embodiment 2. FIG.
FIG. 5 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 2 of the present invention. The air conditioner of Embodiment 2 is basically the same as that of Embodiment 1, and is different from Embodiment 1 in the following points.
That is, there is no heat source side expansion device, branching from the refrigerant circuit 17 between the heat source side heat exchanger 5 and the use side expansion device 4a, and the suction side of the compressor 1 (if the accumulator 14 is provided, the accumulator is A bypass circuit 17A is provided which leads to the suction side of the compressor 1). And the refrigerant cooler 6 similar to Embodiment 1 is installed in the middle of the bypass circuit 17A, and the bypass throttle device 4c and the bypass throttle device 4d are provided before and after the refrigerant cooler 6. is there.
Note that the configuration of the refrigerant cooler 6 and the mounting position of the refrigerant cooler 6 may be the same as those in the first embodiment.

A heating operation operation of the air-conditioning apparatus according to Embodiment 2 will be described. The high-temperature and high-pressure refrigerant that has flowed out of the compressor 1 is condensed in the use side heat exchanger 3 and radiated to the use side. Thereafter, the refrigerant becomes a low-temperature low-pressure liquid or a gas-liquid two-phase state by the use side expansion device 4a, and further becomes a low-temperature low-pressure gas by the heat source side heat exchanger 5, and returns to the compressor 1 through the accumulator 14.
The refrigerant cooler 6 branches the refrigerant from any position between the use side expansion device 4a and the heat source side heat exchanger 5 in the refrigerant circuit 17, and converts power through the refrigerant after passing through the bypass expansion device 4c. The component 8 of the device is cooled. The refrigerant that has passed through the refrigerant cooler 6 is further throttled by the bypass throttle device 4d and enters the accumulator 14 on the low pressure side. In the cooling by the refrigerant cooler 6, by using the

bypass expansion devices

4c and 4d to control the intermediate pressure, it is possible to avoid insufficient cooling capacity and condensation. In this case, an electronic expansion valve, a capillary tube, a double tube, a solenoid valve, a thin tube, or the like can be used as the throttling device.

Next, the cooling operation of the air conditioner according to Embodiment 2 will be described. The high-temperature and high-pressure refrigerant that has flowed out of the compressor 1 becomes a high-pressure liquid by the heat source side heat exchanger 5 and is sent to the use side heat exchanger 3 side. On the use side heat exchanger side, the refrigerant that has become a low-temperature and low-pressure liquid by the use-side expansion device 4a exchanges heat in the use-side heat exchanger 3, becomes a low-temperature and low-pressure gas, returns to the compressor 1 through the accumulator 14.
Further, a part of the refrigerant that has exited the heat source side heat exchanger 5 flows through the bypass circuit 17A according to the throttle amount of the

bypass throttle devices

4c and 4d, and flows to the pipe of the refrigerant cooler 6. The refrigerant that has passed through the refrigerant cooler 6 cools the component 8 of the power converter, and then returns to the compressor 1 through the bypass expansion device 4d and the accumulator 14. In the cooling by the refrigerant cooler 6, by using the

bypass expansion devices

Cooling of the component 8 of the power conversion device during the operations (1) to (3) described in the second embodiment is performed as follows.
When heat loss is generated in the component 8 of the power converter, the heat loss is absorbed by the liquid refrigerant remaining in the pipe constituting the refrigerant cooler 6, and the refrigerant changes its state to become gas. Since the specific gravity of the refrigerant turned into gas is smaller than that of air, it rises through the bypass circuit 17 </ b> A and the refrigerant circuit 17 and reaches the heat source side heat exchanger 5. The gas refrigerant that has moved into the path of the heat source side heat exchanger 5 dissipates lost heat and becomes liquid refrigerant. The liquid refrigerant repeats the natural circulation of returning to the refrigerant cooler 6 through the refrigerant circuit 17 and the bypass circuit 17A due to gravity. Thereby, even when the compressor 1 is stopped, it is possible to dissipate heat by moving the heat loss of the component 8 of the power converter to the heat source side heat exchanger 5.
At this time, since the front-stage bypass expansion device 4c is located between the refrigerant cooler 6 and the heat source side heat exchanger 5, it is necessary to open the refrigerant circulation. Further, since the downstream bypass throttle device 4d is connected to a path leading to the suction side of the compressor 1 or the inlet of the accumulator 14, it is preferably closed in order to continuously cool the refrigerant.

Embodiment 3 FIG.
6 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 3 of the present invention. In the first and second embodiments, when the compressor 1 is stopped, the liquid refrigerant and the gas refrigerant move in the same pipe to move the heat. However, the configuration of FIG. By changing the path, the refrigerant in the refrigerant cooler 6 can be circulated efficiently.
The configuration of the air-conditioning apparatus of the third embodiment, and heating and cooling operations are basically the same as those of the first embodiment, and are different from the first embodiment in the following points.
That is, a bypass circuit 17B is provided which branches from the refrigerant circuit 17 between the refrigerant cooler 6 and the use side expansion device 4a and reaches the inlet of the heat source side heat exchanger for the refrigerant during the cooling operation. A bypass throttle device 42 is provided in the middle of the bypass circuit 17B.
An on-off valve that shuts off the refrigerant flow in the middle of the refrigerant circuit between the connection point between the bypass circuit 17B and the refrigerant inlet side of the heat source side heat exchanger 5 and the discharge side of the compressor 1 during the cooling operation. 43 is provided.
Note that the configuration of the refrigerant cooler 6 and the mounting position of the refrigerant cooler 6 may be the same as those in the first embodiment.

Cooling of the component 8 of the power conversion device during the operations (1) to (3) described above in the third embodiment is performed as follows.
When heat loss is generated in the component 8 of the power converter, the heat loss is absorbed by the liquid refrigerant remaining in the pipe constituting the refrigerant cooler 6, and the refrigerant changes its state to become gas. Since the specific gravity of the refrigerant turned into gas is smaller than that of air, if the expansion device 42 is opened, the gas refrigerant 32 rises through the bypass circuit 17B and reaches the piping in the heat source side heat exchanger 5. In general, a plurality of fins are attached to the heat source side heat exchanger 5 path piping for heat radiation, and a large area for heat radiation to the air is provided. Therefore, the heat loss is efficiently dissipated by moving the gas refrigerant into the heat source side heat exchanger path, and the gas refrigerant becomes a liquid refrigerant. The liquid refrigerant 33 repeats the natural circulation of returning to the refrigerant cooler 6 through the refrigerant circuit 17 by gravity. Thereby, even when the compressor 1 is stopped, it is possible to dissipate heat by moving the heat loss of the component 8 of the power converter to the heat source side heat exchanger 5.
At this time, since the heat source side expansion device 4b is located between the heat source side heat exchanger 5 and the refrigerant cooler 6, it is necessary to open the refrigerant so that the refrigerant is circulated. In addition, since the use side expansion device 4a is connected to a path connected to the use side heat exchanger 3, it is preferable to close the use side expansion device 4a in order to continuously cool the refrigerant. Further, when the refrigerant flowing through the bypass circuit 17B moves toward the inlet side of the accumulator 14 or the suction side of the compressor 1 during heating and toward the discharge side of the compressor 1 during cooling, the on-off valve 43 is closed. It is good to.

1 compressor, 2 way valve, 3 use side heat exchanger, 3a fan, 4a use side throttle device, 4b heat source side throttle device, 4c, 4d bypass throttle device, 5 heat source side heat exchanger, 5a fan, 6 refrigerant cooling 7, power converter, 8 power converter component, 8a power converter compressor component, 8b power converter fan component, 9 second plate, 10 refrigerant inlet pipe, 10a refrigerant inlet pipe , 11 refrigerant outlet pipe, 11a refrigerant outlet pipe end, 12 heat contact surface, 13 heat transfer member, 13a compressor heat transfer member, 13b fan heat transfer member, 14 accumulator, 15 bending part, 16 1st plate, 17 refrigerant circuit, 17A, 17B bypass circuit, 18 heat radiating member, 19 heat radiating member, 30 heat generating part, 31 inside pipe 42 bypass throttle device 43 on-off valve, 71 power converter sheet metal, 100 outdoor unit.

Claims

A refrigerant circuit in which a compressor driven by an electric motor, a use side heat exchanger, at least one expansion device, and a heat source side heat exchanger are connected by piping, and the refrigerant circulates to execute a refrigeration cycle;
A power converter for supplying driving force to the electric motor;
A refrigerant cooler that circulates the refrigerant flowing through the refrigerant circuit and causes the refrigerant to absorb heat from the heat dissipation of the components of the power converter,
The refrigerant cooler is
It has a heat dissipation plate and a heat dissipation pipe through which the refrigerant flows,
The heat radiation pipe includes a refrigerant inlet pipe, a refrigerant outlet pipe, and at least one bent portion that connects the refrigerant inlet pipe and the refrigerant outlet pipe.
The components of the power converter are in surface contact with one surface of the plate, and the heat radiating pipe is in surface contact with the other surface of the plate,
An air conditioner in which a path of the heat source side heat exchanger is positioned above a contact portion between the refrigerant cooler and a component of the power converter.
The air according to claim 1, wherein a heat radiating pipe constituting the refrigerant cooler is accommodated in a groove formed in the plate, and an outer peripheral surface of the pipe and an inner peripheral surface of the groove are in surface contact. Harmony device.
The components of the power converter are fixed on a sheet metal, the components are arranged on the plate via the sheet metal,
The air conditioner according to claim 1 or 2, wherein the sheet metal and the plate are fixed by a fastening member.
The plate is
A first plate to which a cooling surface of a component of the power converter is fixed;
Including a second plate to which the pipe for heat dissipation is fixed;
The air conditioner according to any one of claims 1 to 3, wherein both plates are fixed via a heat radiating member.
The refrigerant cooler is disposed in the refrigerant circuit;
The air conditioner according to any one of claims 1 to 4, wherein the refrigerant flowing through the refrigerant cooler is a total refrigerant flow rate used in the refrigeration cycle.
A bypass circuit is provided that branches from between the heat source side heat exchanger and the use side heat exchanger in the refrigerant circuit and reaches the suction side of the compressor 1;
The air conditioner according to any one of claims 1 to 4, wherein the refrigerant cooler is disposed in the middle of the bypass circuit.
The air conditioner according to claim 6, wherein a refrigerant throttling device is provided at a front stage and a rear stage of the refrigerant cooler of the bypass circuit.
The refrigerant cooler is disposed in the refrigerant circuit;
A bypass circuit branched from a position between the refrigerant cooler and the use side heat exchanger and connected to the refrigerant inlet side of the heat source side heat exchanger during cooling operation;
A bypass throttle device installed in the middle of the bypass circuit,
The air conditioner according to any one of claims 1 to 4, wherein the bypass throttling device is opened only when the compressor is not driven.
Among the refrigerant circuits, the bypass circuit opens and closes a refrigerant between a connection point where the heat source side heat exchanger is connected to the refrigerant inlet side and a discharge side of the compressor during cooling operation. The air conditioning apparatus according to claim 8, further comprising a valve.
A fan for blowing air to the heat source side heat exchanger;
A fan electric motor for driving the fan;
The air conditioner according to any one of claims 1 to 9, wherein the fan motor is driven by the power converter.