JP2011202889A - Cooling structure of electric component in air conditioner - Google Patents

Abstract

An object of the present invention is to reduce the influence of heat on peripheral components from a plurality of inverter boards housed in an electrical component box and suppress deterioration of the peripheral components.
An outdoor unit 11 of an air conditioner 10 houses a plurality of inverter boards 32a and 32b for driving a plurality of variable capacity compressors 30a and 30b, respectively, and the inverter boards 32a and 32b. In addition, an electrical component box 23 into which cooling air is introduced is provided. The inverter boards 32a and 32b are arranged such that the one that generates less heat is positioned upstream of the cooling air flow direction.
[Selection] Figure 2

Description

  The present invention relates to a cooling structure for electrical components in an air conditioner.

  The air conditioner for adjusting indoor temperature and humidity has a built-in variable capacity (capacity variable) type compressor that can set the operation speed by inverter control to enable finer air conditioning control. The one with the outdoor unit is the mainstream. In addition, outdoor units equipped with a plurality of compressors may be used for relatively large air conditioners used in large-scale facilities such as buildings and large stores. Some are all variable in capacity (see, for example, Patent Document 1).

  On the other hand, electrical components such as control boards, inverter boards for driving compressors, reactors, and capacitors are built in the outdoor unit, and these are electrically connected to protect against water droplets, dust, and insects. It is stored in a product box. Inverter boards and reactors housed in the electrical component box generate a large amount of heat, and there is a risk that deterioration of surrounding parts will be accelerated by the generated heat, so air introduced into the outdoor unit is also introduced into the electrical component box. As a result, the electrical component box is cooled (for example, see Patent Document 2).

International Publication No. 2004/088821 JP 2002-228184 A

  When a plurality of variable capacity compressors are built in the outdoor unit, a plurality of inverter boards for driving each compressor are accommodated in the electrical component box. However, since the inverter board generates a large amount of heat as described above, the influence of heat exerted on the surrounding parts by the plurality of inverter boards becomes more prominent particularly when the operation speed of the compressor is high. Therefore, it is necessary to consider the arrangement of the inverter board so that the cooling is performed more effectively in the electrical component box.

  The present invention relates to a cooling structure for an electrical component in an air conditioner that can reduce the thermal influence on the surrounding components from a plurality of drive control components housed in an electrical component box and can suppress degradation of the surrounding components. The purpose is to provide.

(1) The present invention includes a plurality of drive control parts for driving and controlling a plurality of variable capacity compressors, and an electrical component box that houses the drive control parts and into which cooling air is introduced. In the cooling structure of the electrical component in the air conditioner
The drive control component is arranged such that a component that generates less heat is positioned upstream of the flow direction of the cooling air.

  According to this configuration, since the drive control component with less heat generation is arranged upstream in the flow direction of the cooling air inside the electrical component box, the temperature rise of the cooling air after cooling the drive control component is A drive control component that is not so large and is disposed on the downstream side in the same direction and that generates more heat can be suitably cooled. Therefore, the influence of the heat generated by the drive control components arranged on both the upstream side and the downstream side on the surrounding components can be reduced, and deterioration of these surrounding components can be suppressed.

(2) The present invention is for driving and controlling a plurality of variable capacity compressors that have the same capability as each other and whose capability drooping control is performed when the operating state reaches a predetermined droop setting value. In the cooling structure of the electrical component in the air conditioner including a plurality of drive control components and the electrical component box that houses the drive control components and into which the cooling air is introduced,
The drive control component is arranged such that a component that controls the compressor with a smaller droop setting value is positioned on the upstream side in the flow direction of the cooling air.

  In general, in an air conditioner, for example, when an air conditioning load that exceeds a predetermined operating range occurs, drooping control is performed to reduce the operating speed of the compressor and protect the compressor. In the present invention, in the high rotation range of the compressor where droop control works, the drive control component for driving and controlling the compressor having a smaller predetermined droop setting value is the drive control component of the compressor having a larger droop setting value. The current that flows is smaller, and the heat generation is also smaller. Therefore, in the present invention, the drive control component with less heat generation is arranged on the upstream side in the flow direction of the cooling air inside the electrical component box, and the temperature of the cooling air after cooling the drive control component The rise is not so great, and the drive control component that generates more heat and is disposed downstream in the same direction can be suitably cooled. Therefore, the thermal influence on the components arranged around the drive control components arranged on both the upstream side and the downstream side is reduced, and deterioration of these surrounding components can be suppressed.

(3) The droop setting value may be a current value input to the drive control component. Since the heat generation increases as the current value input to the drive control component increases, the heat generation can be suppressed by setting the upper limit value (the droop setting value) low.

(4) The droop setting value may be a temperature of the drive control component or an ambient temperature thereof. When the temperature of the drive control component or the surrounding temperature is high as described above, the heat generation of the drive control component is large. Therefore, the heat generation is suppressed by setting the upper limit value (the droop setting value) low. be able to.

(5) In addition, the present invention houses a plurality of drive control parts for driving and controlling a plurality of variable capacity compressors having different abilities, and contains the drive control parts, and cooling air is contained therein. In the cooling structure of the electrical component in the air conditioner equipped with the electrical component box to be introduced,
The drive control component is arranged such that a component that controls the drive of a compressor having a smaller capacity is located on the upstream side in the flow direction of the cooling air.

  According to this configuration, when each compressor is driven at the maximum operating rotational speed, the drive control component for driving the compressor having a smaller capacity is the drive for driving the compressor having a larger capacity. The flowing current value is smaller than that of the control component, and heat generation is also reduced. Therefore, in the present invention, the drive control component with less heat generation is arranged on the upstream side in the flow direction of the cooling air inside the electrical component box, and the cooling air after cooling the drive control component is arranged. The temperature rise does not increase so much, and the drive control component that generates more heat and is disposed on the downstream side in the same direction can be suitably cooled. Therefore, it is possible to reduce the influence of the heat generated by the drive control components arranged on both the upstream side and the downstream side on the surrounding components, and to suppress the deterioration of these surrounding components.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal influence which the surrounding components receive from the several drive control components accommodated in the electrical component box can be decreased.

It is a schematic structure figure showing the air harmony device concerning a 1st embodiment of the present invention. It is a schematic diagram which shows the outdoor unit of an air conditioning apparatus. It is a schematic diagram which shows an electrical component box. It is a schematic diagram which shows the electrical component box of the air conditioning apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the electrical component box of the air conditioning apparatus which concerns on the 3rd Embodiment of this invention.

<< First Embodiment >>
[Overall configuration of air conditioner]
FIG. 1 is a configuration diagram illustrating an air conditioner 10 according to an embodiment of the present invention.
The air conditioning apparatus 10 according to the present embodiment includes a refrigerant circuit that performs a vapor compression refrigeration cycle by circulating the refrigerant. The refrigerant circuit includes an outdoor unit (heat source unit) 11, an indoor unit (use unit) 12, and a refrigerant pipe 13 connecting them.

The indoor unit 12 includes an expansion mechanism 15, an indoor heat exchanger 16, and a fan 17. The expansion mechanism 15 uses an electric expansion valve capable of adjusting the refrigerant pressure and the refrigerant flow rate.
The indoor side heat exchanger 16 is, for example, a cross fin tube type heat exchanger, and is used to exchange heat with indoor air. The indoor unit 12 is configured to take indoor air into the indoor unit 12 by the fan 17, exchange heat with the indoor heat exchanger 16, and then blow it out indoors. In addition, in the air conditioning apparatus 10 of this Embodiment, the indoor unit 12 is made into one unit, However, Two or more indoor units 12 may be connected in parallel.

  The outdoor unit 11 includes compressors 30 a and 30 b, an outdoor heat exchanger 18, a four-way switching valve 19, and a fan 20. The outdoor unit 11 is provided with two compressors 30a and 30b, and these two compressors 30a and 30b are connected in parallel. Each of the compressors 30a and 30b is a variable capacity type (capacity variable type) compressor, and the built-in electric motor is inverter-controlled by the controller 21, whereby the operating rotational speed of the electric motor is stepwise or continuously. It is possible to change.

  The outdoor heat exchanger 18 is a cross fin tube type heat exchanger, for example, and is used for exchanging heat with a refrigerant using air as a heat source. The outdoor unit 11 is configured to take outside air into the inside by the fan 20, perform heat exchange with the outdoor heat exchanger 18, and then blow out to the outside.

The four-way switching valve 19 reverses the flow of the refrigerant, switches the refrigerant discharged from the compressors 30a and 30b to the outdoor heat exchanger 18 and the indoor heat exchanger 16, and supplies the cooling operation and the heating operation. And can be switched.
Specifically, at the time of cooling operation, the four-way switching valve 19 is switched as indicated by a solid line, whereby the refrigerant flows in the direction indicated by the solid line arrow, whereby the refrigerant discharged from the compressors 30a and 30b is allowed to flow outside the outdoor heat exchanger. 18 and the refrigerant that has passed through the expansion mechanism 15 is supplied to the indoor heat exchanger 16. At this time, the outdoor heat exchanger 18 functions as a condenser, condenses and liquefies the high-temperature and high-pressure gas refrigerant compressed by the compressors 30a and 30b, and the indoor heat exchanger 16 functions as an evaporator and expands. The low-temperature and low-pressure liquid refrigerant after passing through the mechanism 15 is evaporated and vaporized.

  During the heating operation, the refrigerant flow is reversed by switching the four-way switching valve 19 as indicated by the dotted line, and the refrigerant flows in the direction indicated by the dotted arrow. As a result, the outdoor heat exchanger 18 functions as an evaporator to evaporate and vaporize the low-temperature and low-pressure liquid refrigerant after passing through the expansion mechanism 15, and the indoor heat exchanger 16 functions as a condenser. The high-temperature and high-pressure gas refrigerant compressed by 30a and 30b is condensed and liquefied.

  The expansion mechanism 15, the four-way switching valve 19, the compressors 30a, 30b, and the like are operated by a controller (control unit) 21 in accordance with an on / off operation of an operation switch of the air conditioner 10 and sensor outputs such as a temperature sensor and a pressure sensor. Be controlled. In particular, the compressors 30 a and 30 b are operation-controlled by the controller 21 so as to satisfy the required capacity corresponding to the air conditioning load of the indoor unit 12. The air conditioning load varies depending on, for example, the indoor air condition (temperature, humidity), and when a plurality of indoor units 12 are connected, the operation of any indoor unit 12 is performed. It also fluctuates when is started or stopped.

[Configuration of outdoor unit]
FIG. 2 is a schematic diagram of an outdoor unit of the air conditioner shown in FIG.
The outdoor unit includes a housing 23 that is long in the vertical direction, and the outdoor heat exchanger 18, the compressors 30a and 30b, the fan 20, and the controller 21 are accommodated in the housing 23. Moreover, the fan 20 is arrange | positioned at the upper part of the housing | casing 21, and is comprised so that air may flow upwards from the downward direction.

  The outdoor heat exchanger 18 is formed in a U shape in plan view so as to follow the left and right side surfaces and the back surface of the housing 21. In addition, air intakes are formed on the left and right side surfaces and the back surface of the housing 21. The outdoor heat exchanger 18 is configured to exchange heat between the air taken into the housing 23 by driving the fan 20 and the refrigerant.

  The compressors 30a and 30b are disposed at the lower part of the housing 23, and are connected to the outdoor heat exchanger 18 and the refrigerant pipe 13 (see FIG. 1) and to the controller 21 by electric wiring. The two compressors 30a and 30b are both variable capacity compressors whose capacity can be variably set by adjusting the operating rotational speed. The compressors 30a and 30b have different capacities. In the present embodiment, the compressor (first compressor) 30a is a large capacity compressor, and the compressor (second compressor) 30b is a small capacity compressor.

  The controller 21 is built in the housing 21 in a state of being housed in the electrical component box 40. In the electrical component box 40, various electrical components such as a reactor, a noise filter, and electrical wiring are housed in addition to the control board 31 and the inverter boards 32a and 32b constituting the controller 21.

  As shown in FIG. 3, an air inlet 23a is formed on the lower surface of the electrical component box 23, and an air outlet 23b is formed on the upper surface. The electrical component box 23 is configured to take the air flow formed by the fan 20 into the electrical component box 23 from the air inlet 23a, cool the internal electrical components, and then discharge the airflow from the air outlet 23b. ing. That is, the cooling air flows in the electrical component box 23 from below to above.

The control board 31 is a printed board in which a processor, a memory, and the like are mounted on a board in which a conductor pattern is printed on a resin board such as an epoxy resin.
The inverter boards 32a and 32b are mounted on a resin board on which a conductor pattern is printed, such as diodes and capacitors that form a rectifying and smoothing circuit, and power elements such as IGBTs that form a drive circuit (inverter circuit). Printed circuit board. Further, the inverter boards 32a and 32b are supplied with electric power from a commercial power source and operate a power element based on a control signal from the control board 31 to supply a drive current to the compressors 30a and 30b. Is configured.

  The inverter boards 32a and 32b are composed of a first inverter board 32a for driving and controlling the large capacity first compressor 30a and a second inverter board 32b for driving and controlling the small capacity second compressor 30b. They are arranged in the product box 23 in the vertical direction. More specifically, with reference to the flow direction of the cooling air in the electrical component box 23, the second inverter board 32b is arranged on the upstream side, and the first inverter board 32a is arranged on the downstream side. Therefore, the cooling air introduced into the electrical component box 23 first cools the second inverter board 32b on the upstream side, and then cools the first inverter board 32a on the downstream side.

  Since the second inverter board 32b supplies a drive current to the second compressor 30b having a small capacity, the compressor 30a having a large capacity particularly in a high rotation range (near the maximum rotation speed) of the compressors 30a and 30b. The heat generation is smaller than that of the first inverter board 32a that supplies the drive current to the first inverter board 32a. Therefore, the temperature of the cooling air introduced into the electrical component box 23 is reduced as the second inverter board 32b is cooled. Therefore, the first inverter board 32a disposed on the downstream side can be cooled by the relatively low-temperature cooling air, and the first inverter board 32a that generates more heat can be effectively cooled.

  Therefore, not only the electric components such as the electric wiring arranged around the second inverter board 32b that generates a small amount of heat but also the electric parts arranged around the first inverter board 32a that generates a large amount of heat can be used. It is difficult to be affected by heat due to the heat generated by 32b, and deterioration due to the heat can be suppressed. Therefore, it is possible to increase the durability of the electrical components housed in the electrical component box 23 and to increase the service life.

  In the present embodiment, the outdoor unit 11 includes two compressors 30a and 30b, but may include three or more compressors. Also in this case, the compressors are variable capacity compressors having different capacities, and an inverter board that supplies a drive current to each compressor is provided in the electrical component box 23.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described. The main difference between the present embodiment and the first embodiment is the configuration of the compressors 30a and 30b. In the first embodiment, the plurality of compressors 30a and 30b have different capacities. However, in the present embodiment, the plurality of compressors 30a and 30b have the same capacity. However, this is the same as the first embodiment in that each of the compressors 30a and 30b is a variable capacity type.

  Further, as shown in FIG. 4, the control board 31 of the controller 21 reduces the operating rotational speed of each of the compressors 30a and 30b when, for example, the indoor air conditioning load increases beyond a predetermined operating range. Drooping means 50 for preventing overload operation. The drooping means 50 monitors the detection values of the current sensors 51a and 51b that detect the current values input to the inverter circuits of the first and second inverter boards 32a and 32b, and sets the detection values to a predetermined droop setting value. When it reaches, the drive circuit of the 1st, 2nd inverter board | substrates 32a, 32b is controlled so that the electric current value supplied to the 1st, 2nd compressor 30a, 30b may be decreased.

Further, droop means 50 of this embodiment includes a droop set value alpha ₁ for the first inverter substrate 32a, and a droop set value alpha ₂ for the second inverter substrate 32 b, alpha _1> alpha to be ₂ Relationship It is set. Therefore, the first compressor 30a that is driven and controlled by the first inverter board 32a can be driven to a higher rotation, and the second compressor 30b that is driven and controlled by the second inverter board 32b is the first compressor 30a. Driving is limited at a lower rotation than that.

  Therefore, in the high rotation range of the first and second compressors 30a and 30b in which the drooping control works, the heat generation of the second inverter board 32b is smaller than the heat generation of the first inverter board 32a. The cooling air introduced into the box 23 does not rise so much even when the second inverter board 32b on the upstream side is cooled, and can suitably cool the first inverter board 32a on the downstream side that generates more heat. . As a result, as in the first embodiment, not only the electrical components disposed around the second inverter board 32b that generates a small amount of heat, but also the first inverter board 32a that generates a large amount of heat. The electrical components are also less likely to be affected by heat from the inverter board 32a, and deterioration due to the heat can be suppressed. For this reason, it is possible to improve the durability of the electrical components housed in the electrical component box 23.

<< Third Embodiment >>
Next, a third embodiment of the present invention will be described.
As shown in FIG. 5, the present embodiment is common to the second embodiment in that the control board 31 (controller 21) includes the hanging means 52, but the manner of the hanging means 52 is different. Yes. That is, the drooping means 52 of the present embodiment monitors the detection values of the temperature sensors 53a and 53b that detect the temperature of the first and second inverter boards 32a and 32b or the surrounding (neighboring) temperature, and the detected value When the value reaches a predetermined droop setting value, the drive circuit of the first and second inverter boards 32a and 32b is controlled so as to decrease the drive current value supplied to the first and second compressors 30a and 30b. .

Further, droop means 52 of the present embodiment includes a droop set value beta ₁ to the first inverter substrate 32a, and a droop set value beta ₂ for the second inverter board 32b, so that beta _1> beta ₂ relationship It is set. Therefore, the first inverter board 32a is allowed to generate heat until the temperature becomes higher, and conversely, the second inverter board 32b is limited in heat generation at a lower temperature than the first inverter board 32a.

  Therefore, in the high rotation range of the first and second compressors 30a and 30b in which the drooping control works, the heat generation of the second inverter board 32b is smaller than the heat generation of the first inverter board 32a. The cooling air introduced into the box 23 does not rise so much even when the second inverter board 32b on the upstream side is cooled, and can suitably cool the first inverter board 32a on the downstream side that generates more heat. . As a result, as in the first embodiment, not only the electrical components disposed around the second inverter board 32b that generates a small amount of heat, but also the first inverter board 32a that generates a large amount of heat. The electrical components are also less likely to be affected by heat from the inverter board 32a, and deterioration due to the heat can be suppressed. For this reason, it is possible to improve the durability of the electrical components housed in the electrical component box 23.

The present invention is not limited to the embodiment described above, and can be appropriately changed in design.
For example, in the second and third embodiments, the drooping means 50 and 52 have the detected current values input to the drive circuits of the first and second inverter boards 32a and 32b as the droop setting values, The detected values of the temperature of the second inverter boards 32a and 32b or their ambient temperature are employed, but other values may be employed. For example, the discharge pressure of the compressors 30a and 30b, the refrigerant condensation temperature, the input voltage to the drive circuits of the inverter boards 32a and 32b, and the like can be adopted as the droop setting value.

10: Air conditioner 30a: First compressor 30b: Second compressor 31: Control board 32a: First inverter board (drive control component)
32b: Second inverter board (drive control component)
50: Drooping means 51a, 51b: Current sensor 52: Drooping means 53a, 53b: Temperature sensor

Claims (5)

A plurality of drive control parts (32a, 32b) for driving and controlling a plurality of variable capacity compressors (30a, 30b) and the drive control parts (32a, 32b) are housed, and cooling air is introduced. In the cooling structure of the electrical component in the air conditioner comprising the electrical component box (23) to be operated,
The drive control component (32a, 32b) is arranged such that the one that generates less heat is positioned upstream of the flow direction of the cooling air. . A plurality of variable capacity compressors (30a, 30b) that have the same ability and that control the droop of capacity when the operating state reaches a predetermined droop setting value. Electric component cooling structure in an air conditioner having a drive control component (32a, 32b) and an electrical component box (23) into which the drive control component (32a, 32b) is housed and into which cooling air is introduced In
The drive control components (32a, 32b) are arranged so that the drive control of the compressor (30b) having a smaller droop setting value is located upstream of the cooling air flow direction. A cooling structure for electrical components in an air conditioner.   The cooling structure for an electrical component in an air conditioner according to claim 2, wherein the drooping set value is set by a current value input to the drive control component (32a, 32b).   The cooling structure for an electrical component in an air conditioner according to claim 2, wherein the drooping set value is set according to a temperature of the drive control component (32a, 32b) or an ambient temperature thereof. A plurality of drive control parts (32a, 32b) for driving and controlling a plurality of variable capacity compressors (30a, 30b) having different abilities, and the drive control parts (32a, 32b) are housed. In the cooling structure for electrical components in the air conditioner having an electrical component box (23) into which cooling air is introduced,
The air conditioner characterized in that the drive control component (32a, 32b) is arranged so that the component that drives the compressor (30b) having a smaller capacity is located upstream of the flow direction of the cooling air. Cooling structure for electrical parts.

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