JPH0375424A - Heat pump apparatus and its operation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat pump system for cooling a control device such as an inverter control unit, and a method of operating the same.

(Prior Art) Utility Model Application Publication No. 19535/1986 can be mentioned as a conventional technology regarding this type of heat pump system.

In this conventional example, as shown in FIG. 5, an outdoor heat exchanger 1 and a capillary tube 2 of an outdoor unit Y in an air conditioner, an indoor heat exchanger 3 of an indoor unit X, and a four-way switching valve 4
and compressor 5 are sequentially connected by refrigerant piping 6. The low pressure pipe 10 in this refrigerant pipe 6 is connected to the heat sink 11
It is arranged so that heat can be transferred to the power transistor 12 of the inverter control unit via the low-pressure pipe IO, and the power transistor 12 is cooled by the low-temperature refrigerant flowing through the low-pressure pipe IO. In addition, 13 is a ventilation fan.

(Problems to be Solved by the Invention) However, in the conventional example described above, there is a problem in that dew condensation tends to occur in the low-temperature low-voltage pipe 10 during high humidity such as in summer, and the power transistor 12 tends to suffer from poor insulation due to the condensed water. There is also the problem that vibrations of the low-pressure pipe 10 near the compressor 5 are transmitted to the power transistor 12, impairing the reliability of the power transistor 12 and the like.

This invention has been made to solve the above-mentioned conventional drawbacks, and its purpose is to prevent insulation failure and decrease in reliability of the heating element while cooling the heating element. The purpose of the present invention is to provide a heat pump system and an operating method thereof.

(Means for Solving the Problems) Therefore, in the heat pump system according to the first aspect, the pressure pump 5, the outdoor heat exchanger 1, the pressure reducing mechanism 2, and the indoor heat exchanger 3 are connected by a refrigerant pipe 6 to A heat pump system comprising a control device 20 that forms a circulation path and has a heat generating element 12, in which the refrigerant pipe 6 between the outdoor heat exchanger 1 and the pressure reduction mechanism 2 can exchange heat with the heat generating element 12. It is located in

In the heat pump system according to the second aspect, the control device 20 includes an electrical component 21, and further includes a blower fan 13 that can blow air to the control device 20, and a temperature sensor 22 that measures the temperature inside the control device 20. and fan control for controlling the operation of the blower fan 13 based on the temperature signal 23 from the temperature sensor 22 so as to maintain the temperature inside the refrigerator below the reference temperature TG corresponding to the life reduction temperature T of the electrical component 21. A section 24 is provided.

Furthermore, in a third claim, there is provided a method for operating the heat pump system according to the first claim, in which in the heating operation cycle, the heat generating element 12 and the refrigerant pipe 6 are disposed so as to be able to exchange heat with each other. Heat radiation from the element 12 is recovered.

(Function) In the first claim, when the heat pump system is operated, the refrigerant flows while exchanging heat between the indoor heat exchanger 3 and the outdoor heat exchanger 1, and the refrigerant has a temperature not extremely lower than the dew point temperature. The heating element 12 is cooled by the refrigerant pipe 6 between the outdoor heat exchanger 1 and the pressure reduction mechanism 2 through which the heat-generating element 12 flows. Therefore, there is no possibility that condensed water will come into contact with the heating element 12. Furthermore, since the refrigerant pipe 6 between the outdoor heat exchanger 1 and the pressure reduction mechanism 2 is located away from the compressor 1, which is a source of vibration, the heat generating element 12 is also prevented from vibrating.

Further, in the second claim, the temperature inside the refrigerator is measured by the temperature sensor 22, and the temperature signal 23 from the temperature sensor 22 is inputted to the fan control section 24. Blow fan 13 to maintain temperature
to drive. Therefore, the electrical component 21 is cooled to below the reference temperature TG by the air blown from the blower fan 13.

Furthermore, in the third claim, the refrigerant pipe 6 between the outdoor heat exchanger 1 and the pressure reduction mechanism 2 is heated by the heat generated by the heating element 12,
The heating element 12 is connected to the refrigerant flowing inside the refrigerant pipe 6.
The heating capacity is improved by the amount of heat generated by the heating element 12 during heating operation of the heat pump system.

(Example) First, a specific example of the heat pump system of the present invention will be described in detail with reference to the drawings. Note that the first
In the drawings that follow, the parts indicated by the same reference numerals as in the conventional example of FIG. 5 indicate the same or equivalent parts.

In FIG. 2 showing an outdoor unit Y of an air conditioner employing the heat pump system of the present invention, the outdoor unit Y is provided with an outdoor heat exchanger l, a compressor 5, an inverter control unit 20 (control device), etc. There is. This inverter control unit 20 accommodates an inverter equipped with a power transistor 12 as a heat generating element, electrical components 21 such as a capacitor, etc., and air is introduced into the inverter control unit 20 by an outdoor fan 13. is being done. The heat-resistant temperature S of the power transistor 12 is, for example, about 105°C, and the negative electrical component 21
The lifespan reduction temperature T at which the lifespan decreases is, for example, 60°C.

Further, the power transistor 12 is in contact with a cooling section 30 of the refrigerant pipe 6, which will be described in detail later, via the heat sink 11, and the cooling section 30 and the power transistor 12 are arranged so as to be able to exchange heat. A thermistor 22 (temperature sensor) is disposed within the inverter control unit 20, and the thermistor 22 measures the internal temperature of the inverter control unit 20. In FIG. 1, which shows the piping system of the heat pump system, the cooling section 30 of the cooling piping 6 corresponds to the refrigerant piping 6 between the outdoor heat exchanger 1 and the capillary tube 2 (pressure reduction mechanism). The section 30 is configured to cool the power transistor 12 via the heat sink 11.

In FIG. 2, the thermistor 22 measures the internal temperature TO of the inverter control unit 20 in which electrical components 21 are housed, and the temperature signal 23 is
The fan control unit 24 is used to control the operation of the fan. The fan control unit 24 is provided with an arithmetic circuit 25, a drive circuit 26, etc., and the arithmetic circuit 25 determines whether the temperature inside the refrigerator is the above-mentioned life reduction temperature T based on the above-mentioned temperature signal 23.
When the reference temperature TG corresponding to the
A drive signal 27 for the outdoor fan 13 is output from the controller.

To explain the above cooling control of the electrical components 21 using the flowchart of FIG. 3, when the outdoor fan 13 is stopped, step S
1, the temperature inside the refrigerator TD is measured by the thermistor 22, and a temperature signal 23 is output. Next, in step S2, the reference temperature TG and the internal temperature TD are compared, and if the internal temperature TD is higher than the reference temperature TG (YES), the process proceeds to step S3, where the electrical components 21 are cooled. If it is determined that it is necessary, the outdoor fan 13 is driven to blow air into the inverter control unit 20 to cool the electrical components 21.

Then, the process returns from step S3 to step S1, and the above-described control is repeated. On the other hand, if the internal temperature TO is the same or lower than the reference temperature TG, the outdoor fan 13 continues to be stopped.

Next, the operating state of the device according to the above embodiment will be explained.

During both cooling and heating, refrigerant at a temperature not extremely lower than the dew point flows through the cooling section 30 of the refrigeration cycle shown in FIG. The power transistor 12 is cooled via the plate 11. Therefore, as shown in FIG.
If there is no cooling effect due to 0, the power transistor 12
The temperature becomes as shown in the characteristic 31a and exceeds the above-mentioned allowable temperature limit S of the power transistor 12. However, when the power transistor 12 is cooled by the cooling unit 30 as described above, the power transistor 12 is cooled as shown in the characteristic 31 and is prevented from exceeding the above-mentioned heat resistant temperature S.

On the other hand, the temperature inside the refrigerator corresponding to the temperature of the electrical component 21 is
is a reference temperature T that is slightly lower than T, which is the life reduction temperature of the electrical component 21, by cooling control by the fan control unit 24.
Maintained below G. In other words, the temperature characteristic 32 when the above cooling control is performed is that the outdoor fan 13 is stopped.
It continues to rise in the range of , and the outdoor fan 13 goes to 0N-O at ■.
When FFfltlJ is controlled, the characteristic 32 also rises and falls, and the outdoor fan 13 is driven at (2) to maintain it below the reference temperature TG. If the cooling control by the outdoor fan 13 as described above is not performed, the temperature of the electrical component 21 exceeds the reference temperature TG and the reduced life temperature T as shown in characteristic 32a.

Next, in the operating method of the heat pump system during heating, as is well known in FIG.
However, before flowing into the outdoor heat exchanger 1, the cooling section 30 receives heat from the power transistor 12, and the cooling section 30 heats the refrigerant.

Therefore, the waste heat of the power transistor 12 is transferred to the cooling section 3.
It is recovered as a refrigerant using O, and is reused as heat during heating in the indoor heat exchanger 3.

Although specific embodiments of this invention have been described above,
This invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the invention. For example, in the above embodiments, a capillary tube 2 is used as the pressure reducing mechanism. However, it is also possible to use a built-in mechanism such as a pressure reducing valve.

(Effects of the Invention) As described above, in the heat pump system of the first claim, the heating element is installed in the refrigerant pipe between the outdoor heat exchanger and the pressure reduction mechanism through which the refrigerant whose temperature is not extremely lower than the dew point temperature flows. This eliminates the risk of condensed water coming into contact with the heating element. Furthermore, since the refrigerant pipe between the outdoor heat exchanger and the pressure reducing mechanism is located away from the compressor, which is the source of vibration, the heat generating element is also prevented from vibrating.

Furthermore, in the second claim, the blower fan can be driven to maintain the internal temperature at a reference temperature or lower, and the electric component is cooled to the reference temperature or lower by the air blown from the blower fan. .

Furthermore, in the third claim, in the heating operation cycle, the heat generated by the heat generating element is recovered into the refrigerant flowing inside the refrigerant pipe between the outdoor heat exchanger and the pressure reducing mechanism. It becomes possible to improve the heating capacity by the amount of heat generated.

[Brief explanation of drawings]

Fig. 1 is a piping system diagram showing a heat pump system according to an embodiment of the present invention, Fig. 2 is a structural diagram of an outdoor unit, and Fig. 3
FIG. 4 is a flowchart showing a cooling control process, FIG. 4 is a graph showing changes in temperature over time, and FIG. 5 is a structural diagram showing a conventional example. l...Outdoor heat exchanger, 2...Capillary tube,
3... Indoor heat exchanger, 5... Compressor, 6... Refrigerant piping, 20... Inverter control unit (control device)
, 21... Electrical component, 22... Thermistor (temperature sensor), 24... Fan drive unit. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. Compressor (5), outdoor heat exchanger (1), pressure reduction mechanism (2)
), the indoor heat exchanger (3) is connected with the refrigerant piping (6) to form a refrigerant circulation path, and the heat pump system is equipped with a control device (20) having a heating element (12), A heat pump system characterized in that a refrigerant pipe (6) between a heat exchanger (1) and a pressure reducing mechanism (2) is arranged so as to be able to exchange heat with the heating element (12). 2. The control device (20) includes an electrical component (21),
Furthermore, a blower fan (
13), a temperature sensor (22) that measures the internal temperature of the control device (20), and a temperature signal (23) from which the electrical component (21) is lowered in service life based on the temperature signal (23) from the temperature sensor (22). and a fan control section (24) for controlling the operation of the ventilation fan (13) so as to maintain the internal temperature below the reference temperature (TG) corresponding to (T). A heat pump system according to claim 1. 3. An operating method for the heat pump system according to the first aspect, in which, in the heating operation cycle, the heating element ( 12) A method for operating a heat pump system, characterized by recovering heat released from the heat pump system.