JPH05157372A - Electric part box cooler for air conditioner - Google Patents

Abstract

PURPOSE:To prevent dew condensation inside an electric part box and simplify a refrigerant circuit. CONSTITUTION:A refrigerant circuit 13 is formed of a compressor 14, a four-way valve 15, a heat exchanger on non-use side 16, a heat exchanger on use side 17, an accumulator 18, a pressure reducing means 19 and an intake piping 20. An auxiliary cooler 22 is additionally provided to work as a heat exchanger with respect to an electric part box 21. A first bypass circuit 23 is connected by piping to the intake piping 20 from the bottom of the accumulator 18 through the auxiliary cooler 22, and a flow rate adjusting means 24 is provided between the accumulator 18 and the auxiliary cooler 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric box cooling device for an air conditioner in which the capacity of a compressor is controlled by an inverter.

[0002]

2. Description of the Related Art Conventionally, there is an air conditioner that uses a transistor inverter to control the capacity of a compressor.
The power transistors, diode modules, capacitors, and the like that form the inverter need to be cooled from the viewpoint of long life and prevention of deterioration of performance because the temperature rises due to heat generation. The most common cooling method is forced cooling with wind.

However, in the case of this air cooling system, there is a problem that dust in the cooling air is apt to adhere to the surfaces of the electric parts, which lowers the reliability of the parts. Further, when the non-use side heat exchanger of the air conditioner is installed in the machine room, the wind cooling method only causes an increase in ambient temperature, and there is a problem that a sufficient cooling effect cannot be obtained.

Therefore, it has been proposed to use the refrigerant of the air conditioner itself to perform efficient cooling. For example, the one shown in FIG. 3 disclosed in Japanese Utility Model Laid-Open No. 55-1156 is disclosed. is there. In the figure, 1 is a variable capacity compressor driven by an inverter, 2 is a four-way valve, 3 is a non-use side heat exchanger, 4 is a heating decompression device, 5 is a cooling decompression device, and 6 is a use side heat exchange. Vessel, 7 is accumulator, 8 and 9
Is a check valve. Further, 10 is a capillary tube provided in a circuit that reaches the accumulator 7 through the auxiliary cooler 11 from the pipe connecting the decompression devices 4 and 5, and 12 is an electric component box capable of exchanging heat with the auxiliary cooler 11.

The solid arrow indicates the flow direction of the refrigerant during the cooling operation, and the broken arrow indicates the flow direction of the refrigerant during the heating operation.

Next, the operation will be described. First, during the cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 enters the non-use side heat exchanger 3 through the four-way valve 2 and radiates heat to the atmosphere to be condensed and liquefied into a high-pressure liquid refrigerant. Become. This high-pressure liquid refrigerant is guided to the cooling decompression device 5 through the check valve 8 and is decompressed into a low-pressure gas-liquid two-phase refrigerant, which enters the use side heat exchanger 6 and takes heat from the indoor air to cool it. As well as
The refrigerant evaporates into a low-pressure gas refrigerant, which is sucked into the compressor 1 via the accumulator 7.

During the heating operation, by switching the four-way valve 2, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 enters the heat exchanger 6 on the use side and radiates heat to indoor air to heat the refrigerant, and at the same time, the refrigerant itself. Condenses into a high-pressure liquid refrigerant.
The high-pressure liquid refrigerant is decompressed by the heating decompression device 4 via the check valve 9, becomes a low-pressure gas-liquid two-phase refrigerant, is evaporated in the non-use side heat exchanger 3, and is stored in the compressor 1 via the accumulator 7. Inhaled into.

Auxiliary cooler 11 attached to electrical component box 12
The refrigerant supply to the printer will be described. During operation of the compressor 1,
Since the pipe portion connecting the cooling decompression device 5 and the heating decompression device 4 is a high-pressure liquid refrigerant, the low-pressure gas-liquid two-phase refrigerant decompressed by the capillary tube 10 enters the auxiliary cooler 11 and the electrical component box 12 More heat is collected to cool the electrical equipment box 12.

[0009]

However, in the conventional air conditioner, since the capillary tube 10 has the function of adjusting the refrigerant flow rate that influences the cooling performance of the auxiliary cooler 11, the load fluctuation of the compressor 1 is prevented. However, it cannot be adjusted properly. That is,
Since the flow rate of the refrigerant passing through the capillary tube 10 is controlled by the high pressure of the inflow portion of the capillary tube 10, it is almost constant regardless of the capacity of the compressor 1, but an electric heat generating component (not shown) housed in the electrical component box 12 is shown. The heat value of () is almost proportional to the capacity of the compressor 1. Therefore, when the capacity of the compressor 1 is reduced, the cooling performance becomes excessive, and there is a problem that dew condensation occurs in the electric component box 12.

Further, since the ambient temperature during the heating operation is lower than that during the cooling operation, the required cooling performance of the auxiliary cooler 11 may be small, but there is no adjusting function, and there is the same problem as described above.

Further, since it is necessary to supply the refrigerant to the auxiliary cooler 11 during both the cooling operation and the heating operation, it is necessary to always form the high-pressure liquid refrigerant portion in any operation mode, which complicates the refrigerant circuit. There was also a problem.

An object of the present invention is to provide an electric component box cooling device for an air conditioner capable of preventing dew condensation in the electric component box and simplifying the refrigerant circuit.

[0013]

According to a first aspect of the present invention, there is provided an electric box cooling device for an air conditioner, comprising a variable capacity compressor, a four-way valve, a non-use side heat exchanger, a pressure reducing device, a use side heat exchanger and an accumulator. The first bypass circuit that can supply the refrigerant to the auxiliary cooler from the accumulator is provided with a refrigerant circuit consisting of It is connected to a suction pipe of a compressor through an auxiliary cooler, and a flow rate adjusting means is provided between the accumulator and the auxiliary cooler in this first bypass circuit.

According to a second aspect of the present invention, there is provided an electric box cooling device for an air conditioner, which is provided with a refrigerant circuit including a variable capacity compressor, a four-way valve, a non-use side heat exchanger, a pressure reducing device, a use side heat exchanger and an accumulator. , An electric component box containing electric heating components is installed, and an auxiliary cooler is attached to this electric component box to enable heat exchange.
A first bypass circuit capable of supplying a refrigerant to the auxiliary cooler is connected from the accumulator to the suction pipe of the compressor through the auxiliary cooler, and a flow rate adjusting means is provided between the accumulator and the auxiliary cooler in the first bypass circuit. A control for connecting a second bypass circuit to the first bypass circuit in parallel with the auxiliary cooler near the auxiliary cooler from the flow rate adjusting means, providing a valve in the middle of the second bypass circuit, and controlling the opening / closing of the valve. A device is provided.

According to a third aspect of the present invention, there is provided an electric box cooling device for an air conditioner, wherein the control device according to the second aspect is configured such that a predetermined time after the compressor is started,
It is characterized by opening the valve.

According to a fourth aspect of the present invention, there is provided an electric component box cooling device for an air conditioner, wherein the control device according to the second aspect opens the valve during a defrost operation for removing frost accumulated on the non-use side heat exchanger. It is what

According to a fifth aspect of the invention, there is provided an electric component box cooling device for an air conditioner, wherein the control device according to the second aspect closes a valve during a cooling operation,
The feature is that the valve is opened during the heating operation.

[0018]

According to the electric component box cooling device for an air conditioner of the first aspect, the refrigerant circuit having a compressor having a variable capacity and the electric component box accommodating the electric heating component are provided, and the first bypass circuit is provided. Since the accumulator of the refrigerant circuit is connected to the suction pipe of the compressor through the auxiliary cooler attached to the electric component box through the flow rate adjusting means, the pressure difference between the both ends of the first bypass circuit depends on the suction amount of the compressor, The amount of refrigerant supplied to the auxiliary cooler changes according to the capacity of the compressor.

Further, since the first bypass circuit for cooling the electric component box is connected between the accumulator and the suction pipe of the compressor, the first bypass circuit is caused by the pressure difference between the accumulator and the suction pipe. A refrigerant flow from the accumulator to the suction pipe is generated in the circuit, and the refrigerant is supplied to the auxiliary cooler.

According to the electric component box cooling device of the air conditioner of the second aspect, since the second bypass circuit having the valve is provided in parallel with the auxiliary cooler, the cooling of the auxiliary cooler is performed by the circuit of the valve in the control device. You can control the performance.

According to the electric component box cooling device of the air conditioner of the third aspect, the valve of the second bypass circuit is controlled by the control device so as to be circuited for a predetermined time after the compressor is started. Even if there is a large change in pressure, the flow rate of the refrigerant flowing through the auxiliary cooler can be suppressed.

According to the electric component box cooling device for an air conditioner of the present invention, the control device controls the valve of the second bypass circuit so that the valve is operated during the defrost operation. Therefore, the suction pressure of the compressor is extremely lowered. Accordingly, when the temperature of the refrigerant in the auxiliary cooler decreases, the flow rate of the refrigerant flowing in the auxiliary cooler can be suppressed.

According to the electric component box cooling device of the air conditioner of the fifth aspect, the control device controls the valve of the second bypass circuit so that the valve of the second bypass circuit is circuited during the heating operation, so that the flow rate of the refrigerant flowing to the auxiliary cooler during the heating operation. Can be suppressed.

[0024]

【Example】

Example 1. A first embodiment of the present invention is shown in FIG. In the figure, 13 is a refrigerant circuit, and the refrigerant circuit 13 is a compressor 14 driven by an inverter and having a variable capacity, and a four-way valve 1.
5, the non-use side heat exchanger 16, the use side heat exchanger 17, the accumulator 18, the pressure reducing device 19, and the suction pipe 20 of the compressor 14. In the case of the refrigerant circuit 13, a small amount of liquid refrigerant is secured at the bottom of the accumulator 18 by adjusting the structure of the decompression device 19 and the amount of refrigerant enclosed as an air conditioner. Further, 21 is an electric component box accommodating an electric heating component, and 22 is an auxiliary cooler attached to the electric component box 21 so that heat can be exchanged.
Further, reference numeral 23 is a first bypass circuit pipe-connected from the bottom of the accumulator 18 to the suction pipe 20 of the compressor 14 via the auxiliary cooler 22, and a flow rate adjusting means 24 is provided between the accumulator 18 and the auxiliary cooler 22. It is provided.

In the figure, the solid arrow indicates the flow direction of the refrigerant during the cooling operation, and the broken arrow indicates the flow direction of the refrigerant during the heating operation. During the cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 14 enters the non-use side heat exchanger 16 through the four-way valve 15 and radiates heat to the atmosphere to be condensed and liquefied to become a high-pressure liquid refrigerant. .. This high-pressure liquid refrigerant is decompressed by the decompression device 19 to become a low-pressure gas-liquid two-phase refrigerant, enters the heat exchanger 17 on the use side, takes heat from the indoor air to cool it, and the refrigerant evaporates to form a low-pressure gas refrigerant. Next, accumulator 1
8 and is sucked into the compressor 14 via. During heating operation,
By switching the four-way valve 15, the high-temperature and high-pressure gas refrigerant discharged from the compressor 14 enters the use-side heat exchanger 17 and radiates heat to indoor air to heat the refrigerant, and the refrigerant itself is condensed to form a high-pressure liquid. It becomes a refrigerant. High-pressure liquid refrigerant is the decompression device 19
Is reduced in pressure to become a low-pressure gas-liquid two-phase refrigerant, evaporated in the non-use side heat exchanger 16, and sucked into the compressor 14 via the accumulator 18.

Next, the operation of the first bypass circuit 23 will be described. Since high-speed low-pressure gas refrigerant flows through the suction pipe 20, pressure loss occurs due to friction loss, so the pressure inside the suction pipe 20 is lower than the internal pressure of the accumulator 18. Therefore, in the first bypass circuit 23, a refrigerant flow from the accumulator 18 toward the suction pipe 20 of the compressor 14 is generated, so that the low-temperature refrigerant is supplied to the auxiliary cooler 22 and heat is taken from the electric component box 21 to perform cooling. ..

The flow rate adjusting means 24 is capable of preventing an excessive amount of liquid back to the compressor 14, and the auxiliary cooler 2
The refrigerant flow rate is set so as to ensure the cooling performance in No. 2 and is constituted by a pipe orifice or the like. Further, the pressure difference generated at both ends of the first bypass circuit 23 depends on the intake gas amount (refrigerant flow rate) of the compressor 14, and
When the amount of intake gas is increased, the pressure difference is also increased, and the cooling capacity of the auxiliary cooler 22 is also increased.

According to the electric component box cooling device of the air conditioner thus configured, the auxiliary cooler 22 is provided with the first bypass circuit 23 attached to the electric component box 21 from the bottom of the accumulator 18 via the flow rate adjusting means 24. Through compressor 14
Connected to the suction pipe 20 of the first bypass circuit 2
The pressure difference between both ends of 3 depends on the suction amount of the compressor 14.
Therefore, the flow rate of the refrigerant flowing through the auxiliary cooler 22 can be adjusted according to the operating capacity of the compressor 14, and the proper electrical component box 21
Therefore, it is possible to prevent the dew condensation of the electric parts due to the excessive cooling.

Further, the first for cooling the electric component box 21
The bypass circuit 23 of the accumulator 18 and the compressor 1
4 is connected between the suction pipes 20, the pressure difference between the accumulator 18 and the suction pipe 20 causes a flow of the refrigerant from the accumulator 18 to the suction pipe 20 in the first bypass circuit 23, and the auxiliary cooler is provided. Refrigerant is supplied to 22. Thus, regardless of the operation mode, it is not necessary to configure a portion that is always a high-pressure liquid refrigerant, so that the refrigerant circuit 13 can be simplified and an inexpensive air conditioner can be obtained.

Example 2. The second embodiment of the present invention is shown in FIG.
Shown in. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 25 is a first parallel to the auxiliary cooler 22.
The second bypass circuit 25 is connected to the second bypass circuit 25, and the solenoid valve 26 is connected to the second bypass circuit 25. Reference numeral 27 is a control device that controls the opening and closing of the solenoid valve 26.

Next, the operation will be described. Operation during cooling operation and heating operation with refrigerant, and auxiliary cooler 2
The cooling action of the electric component box 21 by 2 is the same as that of the example shown in FIG.

The operation of the second bypass circuit 25 will be described. When the solenoid valve 26 is opened, the refrigerant flowing out of the accumulator 18 via the flow rate adjusting means 24 is split into the auxiliary cooler 22 and the solenoid valve 26 and reaches the suction pipe 20. Therefore, when the electromagnetic valve 26 is opened, the flow rate of the refrigerant flowing through the auxiliary cooler 22 decreases, and the cooling capacity of the electrical component box 21 decreases.

The operation of the control device 27 for the solenoid valve 26 will be described. Since a rapid pressure change occurs immediately after the compressor 14 is started, the refrigerant flow rate into the auxiliary cooler 22 is likely to be excessive, and the electromagnetic valve 26 is opened to suppress the refrigerant flow rate of the auxiliary cooler 22. .. In addition, when the air conditioner is heated, the non-use side heat exchanger 16 is frosted, so that the defrost (defrost) operation is generally performed regularly. During the defrost operation, the suction pressure of the compressor 14 is extremely lowered, the temperature of the refrigerant passing through the auxiliary cooler 22 is lowered more than necessary, and the cooling capacity becomes excessive. Therefore, the solenoid valve 26 is opened to cool the cooling capacity. To reduce. Further, since the ambient temperature of the electric component box 21 is low during the heating operation, the required cooling capacity of the electric component box 21 by the refrigerant may be small, and the electromagnetic valve 26 is opened to reduce the cooling capacity.

Also in the electric component box cooling device for an air conditioner thus configured, the same effect as that of the first embodiment can be obtained. Further, since the second bypass circuit 25 having the electromagnetic valve 26 is provided in parallel with the auxiliary cooler 22, the auxiliary cooler 22 is configured by the control device 27 to circuit the electromagnetic valve 26.
The cooling performance of can be suppressed. That is, the solenoid valve 2 is operated during the defrost operation and the heating operation for a predetermined time after the compressor is started.
6, the flow rate of the refrigerant flowing through the auxiliary cooler 22 can be suppressed, and the cooling capacity can be suppressed.

[0036]

According to the electric component box cooling device for an air conditioner of the first aspect of the present invention, the first bypass is composed of a refrigerant circuit having a variable capacity compressor and an electric component box accommodating electric heating components. Since the circuit was connected to the suction pipe of the compressor through the auxiliary cooler attached to the electrical box from the accumulator of the refrigerant circuit via the flow rate adjusting means, the pressure difference between both ends of the first bypass circuit depends on the suction amount of the compressor. Therefore, it is possible to prevent the amount of the refrigerant supplied to the auxiliary cooler from changing according to the capacity of the compressor, thereby preventing the occurrence of dew condensation in the electric component box.

Further, since the first bypass circuit for cooling the electric component box is connected between the accumulator and the suction pipe of the compressor, the pressure difference between the accumulator and the suction pipe causes the first bypass circuit. The flow of the refrigerant from the accumulator to the suction pipe is generated in the circuit, the refrigerant is supplied to the auxiliary cooler, and the refrigerant circuit can be simplified.

According to the electric component box cooling device of the air conditioner of the second aspect, since the second bypass circuit having the valve is provided in parallel with the auxiliary cooler, the cooling of the auxiliary cooler is performed by the circuit of the valve in the control device. The performance can be controlled and the occurrence of dew condensation in the electrical equipment box can be prevented.

According to the electric component box cooling device for an air conditioner of the third aspect, the control device controls the valve of the second bypass circuit to operate for a predetermined time after the compressor is started. Even if there is a large change in pressure, the flow rate of the refrigerant flowing through the auxiliary cooler can be suppressed.

According to the electric component box cooling device for an air conditioner of the present invention, the control device controls the valve of the second bypass circuit so that the valve is operated during the defrosting operation. Therefore, the suction pressure of the compressor is extremely lowered. Accordingly, when the temperature of the refrigerant in the auxiliary cooler decreases, the flow rate of the refrigerant flowing in the auxiliary cooler can be suppressed.

According to the electric component box cooling device of the air conditioner of the fifth aspect, since the valve of the second bypass circuit is controlled by the control device so as to be circuited during the heating operation, the flow rate of the refrigerant flowing to the auxiliary cooler during the heating operation. Can be suppressed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a conventional air conditioner.

[Explanation of symbols]

 13 Refrigerant circuit 14 Compressor 15 Four-way valve 16 Non-use side heat exchanger 17 Use side heat exchanger 18 Accumulator 19 Pressure reducing device 20 Suction pipe 21 Electrical component box 22 Auxiliary cooler 23 First bypass circuit 24 Flow control means 25 Second Bypass circuit 26 Solenoid valve 27 Control device

Claims (5)

[Claims] 1. A refrigerant circuit comprising a variable capacity compressor, a four-way valve, a non-use side heat exchanger, a pressure reducing device, a use side heat exchanger and an accumulator, an electric box for accommodating electric heat-generating parts, and this electric machine. An auxiliary cooler attached to the product box so that heat can be exchanged; a first bypass circuit connected to the suction pipe of the compressor from the accumulator through the auxiliary cooler and capable of supplying a refrigerant to the auxiliary cooler; An electric component box cooling device for an air conditioner, comprising: a flow rate adjusting means provided between the accumulator and the auxiliary cooler in the bypass circuit. 2. A refrigerant circuit comprising a variable capacity compressor, a four-way valve, a non-use side heat exchanger, a pressure reducing device, a use side heat exchanger and an accumulator, an electric component box containing an electric heating component, and this electric machine. An auxiliary cooler attached to the product box so that heat can be exchanged; a first bypass circuit connected to the suction pipe of the compressor from the accumulator through the auxiliary cooler and capable of supplying a refrigerant to the auxiliary cooler; Flow rate adjusting means provided between the accumulator and the auxiliary cooler in the bypass circuit, and the first cooler in parallel with the auxiliary cooler near the auxiliary cooler from the flow rate adjusting means.
An electric component box cooling device for an air conditioner, comprising a second bypass circuit connected to the bypass circuit, a valve provided in the middle of the second bypass circuit, and a control device for controlling the opening / closing of the valve. 3. The electric component box cooling device for an air conditioner according to claim 2, wherein the control device opens the valve for a predetermined time after starting the compressor. 4. The electric component box for an air conditioner according to claim 2, wherein the control device opens the valve during a defrost operation for removing frost that has frosted on the non-use side heat exchanger. Cooling system. 5. The electric box cooling device for an air conditioner according to claim 2, wherein the control device closes the valve during the cooling operation and opens the valve during the heating operation.