JP2013137132A - Air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an air conditioning device capable of properly performing cooling according to heat generation states of respective function circuits and an air volume of a fan at the cooling of a semiconductor module embedding a plurality of function circuits in one package.SOLUTION: On a heat radiation plate 7, a wide pitch part 7b is formed at a position corresponding to an arrangement region of a first function circuit such that intervals of heat radiation fans are a predetermined value. Further, a narrow pitch part 7a is formed at a position corresponding to an arrangement region of a second function circuit such that the intervals of the heat radiation fans are rendered narrower compared to the wide pitch part 7b. A control device 2 increases an air volume of a fan 3 according to the magnitude of a set operation capacity.

Description

  The present invention relates to an air conditioner, and more particularly to cooling of a semiconductor module.

  In the prior art, for example, a heat dissipating fin is arranged in a flow path through which air flows, a semiconductor module is mounted on the heat dissipating fin, and the semiconductor module is cooled via the heat dissipating fin (for example, Patent Document 1).

JP 2000-11216 (paragraphs [0014] and [0015], FIG. 1)

2. Description of the Related Art Conventionally, it is known to dissipate heat generated from a semiconductor module by attaching a heat radiating plate having heat radiating fins to the semiconductor module serving as a heating element. Such a heat radiating plate is desired to have a thermal design suitable for the heat generation amount of the semiconductor module.
In recent years, composite semiconductor modules in which a plurality of functional circuits constituting a control device are incorporated in one package are used. Such a semiconductor module may have different calorific values for each functional circuit, and cooling suitable for the calorific value is required.

  However, as in the technique of Patent Document 1, when a heat sink having a uniform fin pitch of the heat dissipating fins is attached to the composite semiconductor module and cooled, the function circuit with a small amount of heat generation is used. Becomes an excessive heat dissipation capability, and heat dissipation performance may be insufficient for a functional circuit with a large calorific value, and it is difficult to perform appropriate cooling. For example, if a heat radiating plate corresponding to a functional circuit with a large calorific value is attached so that the heat radiating performance is not insufficient, there is a problem that the heat radiating plate is increased in size and cost.

Further, when the semiconductor module is cooled using air flowing in the outdoor unit as in the technique of Patent Document 1, the air volume passing through the heat radiating fins of the heat radiating plate varies depending on the air volume of the fan of the outdoor unit. Become. The air volume of the fan in such an outdoor unit varies depending on the operation pattern (operation capability) of the air conditioner. In addition, the heat generation amount of a plurality of functional circuits constituting the semiconductor module may also vary depending on the operation pattern (operation capability).
In this way, when a semiconductor module whose calorific value changes individually in each functional circuit depending on the operating capacity is cooled by using air blown from a fan whose air volume varies depending on the operating capacity, cooling suitable for the calorific value is performed by the heat sink. There was a problem that it was difficult to perform.

  The present invention has been made to solve the above-described problems. In cooling a semiconductor module in which a plurality of functional circuits are incorporated in one package, the heat generation state of each functional circuit and the fan air volume are reduced. An air conditioner capable of performing appropriate cooling according to the above is obtained.

  The air conditioner according to the present invention is an air conditioner in which a compressor, a condenser, an expansion means, and an evaporator are connected by a refrigerant pipe to form a refrigerant circuit for circulating the refrigerant. A fan that is provided in a mounted housing and blows air to the condenser or the evaporator; and a control device that controls the compressor and the fan according to a set operation capacity, and the control device includes a plurality of A semiconductor module in which each of the functional circuits is arranged in a single package and a heat radiating plate attached to the semiconductor module and formed with heat radiating fins through which a part of the fan air flows. And at least a part of the plurality of functional circuits includes a first functional circuit whose calorific value does not depend on the driving capability, and a first calorific value that increases as the driving capability increases. The heat dissipation plate is formed with a wide pitch portion having a predetermined interval between the heat dissipating fins at a position corresponding to the arrangement area of the first function circuit. A narrow pitch portion is formed at a position corresponding to the arrangement region, and the gap between the heat dissipating fins is narrower than that of the wide pitch portion, and the control device increases the air volume of the fan as the operating capacity to be set increases. .

  According to the present invention, in cooling a semiconductor module in which a plurality of functional circuits are built in one package, appropriate cooling can be performed according to the heat generation state of each functional circuit and the fan air volume.

2 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 1. FIG. It is the internal structure figure and ventilation path figure of the outdoor unit in Embodiment 1. FIG. It is the figure which showed the internal structure figure of the control apparatus in Embodiment 1, and the cooling means of a heat sink. It is the figure which showed the electric circuit figure and main function of the control apparatus in Embodiment 1. FIG. FIG. 3 is a simplified diagram of the internal structure of the semiconductor module in the first embodiment. It is a figure which shows the relationship between the driving | running pattern in Embodiment 1, and the emitted-heat amount of each function circuit. It is a figure which shows the relationship between the driving | running pattern in Embodiment 1, and the emitted-heat amount of each function circuit. FIG. 3 is a perspective view showing a heat sink and a semiconductor module in the first embodiment. 6 is a diagram illustrating a cooling operation of the semiconductor module in the first embodiment. FIG. It is a figure which shows the air-conditioner operation range at the time of the air_conditionaing | cooling operation in Embodiment 1. FIG. It is a figure which shows transition of the emitted-heat amount in the ambient temperature in Embodiment 1, and an air-conditioning functional force. FIG. 10 is a diagram illustrating another example of the arrangement of the functional circuits in the first embodiment. It is a perspective view which shows the heat sink, semiconductor module, and axial fan in Embodiment 2. FIG. 10 is a diagram illustrating a cooling operation of the semiconductor module in the second embodiment. It is a perspective view which shows the heat sink, semiconductor module, and axial fan which provided the temperature sensor in Embodiment 2. 10 is a perspective view showing a heat sink and a semiconductor module in Embodiment 3. FIG. It is a figure which shows the example of selection of the functional circuit to which the silicon carbide element in Embodiment 3 is applied.

Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 1.
As shown in FIG. 1, the air conditioner is mounted on a compressor 100, a four-way valve 101, an outdoor heat exchanger 102 mounted on the outdoor unit 1, an expansion valve 103 as expansion means, and an indoor unit. The indoor-side heat exchanger 104 thus connected is sequentially connected by a refrigerant pipe, and is provided with a refrigerant circuit for circulating the refrigerant.
The four-way valve 101 switches between the heating operation and the cooling operation by switching the direction in which the refrigerant flows in the refrigerant circuit. In addition, when it is set as the air conditioning apparatus only for cooling or heating, the four-way valve 101 may be omitted. The outdoor heat exchanger 102 functions as a condenser that heats the air or the like with the heat of the refrigerant during the cooling operation, and functions as an evaporator that evaporates the refrigerant and cools the air or the like with the heat of vaporization during the heating operation. To do. The indoor heat exchanger 104 functions as a refrigerant evaporator during the cooling operation, and functions as a refrigerant condenser during the heating operation. The compressor 100 compresses the refrigerant discharged from the evaporator and supplies it to the condenser at a high temperature. The expansion valve 103 expands the refrigerant discharged from the condenser, supplies the refrigerant to a low temperature.

FIG. 2 is an internal structure diagram and a ventilation route diagram of the outdoor unit in the first embodiment.
As shown in FIG. 2, the outdoor unit 1 has a suction port formed on a side surface of a box-shaped housing, and an outdoor heat exchanger 102 (not shown) is disposed along the suction port. A fan 3 is disposed at an air outlet formed by the opening on the top surface of the housing. In such a top flow type outdoor unit 1, when the fan 3 rotates, air (wind 4) is sucked from the suction port on the side surface of the housing and flows in the vertical direction after passing through the outdoor heat exchanger 102. The air is blown upward from the air outlet formed in the upper part of the housing.
In addition, a control device 2 that controls the compressor 100 and the fan 3 is attached inside the casing of the outdoor unit 1, and the structure is such that the wind 4 generated by the rotation of the fan 3 flows through the back surface of the control device 2. ing. Moreover, since the rotation speed of the fan 3 changes depending on the operating state (operating ability) of the air conditioner, the air volume of the wind 4 also changes.

FIG. 3 is a diagram showing the internal structure of the control device and the cooling means for the heat sink in the first embodiment.
As shown in FIG. 3, in the control device 2, a composite semiconductor module 6 in which a plurality of functional circuits are built in one package, and a heat radiation fin attached to the semiconductor module 6 are formed. A heat radiating plate 7 is arranged. The heat radiating plate 7 is attached to, for example, the back surface (side surface of the casing) of the control device 2, and a part of the wind 4 sucked into the casing of the outdoor unit 1 (hereinafter referred to as cooling air 8) has radiating fins. The semiconductor module 6 is cooled by heat exchange between the cooling air 8 and the heat sink 7.

FIG. 4 is an electric circuit diagram and main functions of the control device according to the first embodiment.
As shown in FIG. 4, the control device 2 includes a rectifier circuit unit 9, a booster circuit unit 10, and an inverter circuit unit 11 as a configuration for driving the compressor 100.
The rectifier circuit unit 9 is configured by bridge-connecting rectifier diodes, rectifies an AC voltage from the power supply, and supplies the rectified diode to the booster circuit unit 10.
The step-up circuit unit 10 includes a reactor, a switching element, and a diode. A current flows into the reactor during the ON period of the switching element, and outputs energy stored in the reactor through the diode during the OFF period. The DC voltage from 9 is boosted and output. The output of the booster circuit unit 10 is smoothed by a smoothing capacitor and supplied to the inverter circuit unit 11.
The inverter circuit unit 11 is configured by connecting switching elements to each other, for example, performing PWM control, and driving the motor of the compressor 100 by converting the input DC voltage into an AC of an arbitrary voltage and an arbitrary frequency. Then, the rotation speed of the compressor 100 is varied.

  In the present embodiment, each diode of the rectifier circuit section 9, switching elements and diodes of the boost circuit section 10, and each switching element (including a backflow prevention diode) of the inverter circuit section 11 are incorporated in one package. Thus, the semiconductor module 6 is configured.

FIG. 5 is a simplified diagram of the internal structure of the semiconductor module according to the first embodiment.
As shown in FIG. 5, in the semiconductor module 6, the functional circuits of the rectifier circuit unit 9, the booster circuit unit 10, and the inverter circuit unit 11 are arranged by dividing the arrangement area. In addition, it is good also as a structure which provides the other circuit part 12 in which circuits other than the said functional circuit are arrange | positioned. Here, the other circuit unit 12 is described as having no heating element.
In the following description, the arrangement region of the rectifier circuit unit 9 is referred to as “A”, the arrangement region of the booster circuit unit 10 is referred to as “B”, and the arrangement region of the inverter circuit unit 11 is referred to as “C”.

The semiconductor module 6 generates heat due to Joule heat accompanying energization during operation, but the amount of generated heat is not uniform among the functional circuits. Moreover, the calorific value of each functional circuit varies according to the operation pattern (operating capacity, etc.) of the air conditioner.
In the first embodiment, considering the temperature distribution by the internal structure (layout of the heating element) of the semiconductor module 6 as the heating element, the structure of the heat sink 7 adapted to the distribution and the operation pattern of the air conditioner are By combining them, optimum cooling is achieved.
Hereinafter, after explaining the relationship between the operation pattern and the amount of heat generated by each functional circuit, the configuration of the heat sink 7 will be described.

6 and 7 are diagrams showing the relationship between the operation pattern and the heat generation amount of each functional circuit in the first embodiment. FIG. 6 shows a case where the power supply voltage is low (for example, 200 V), and FIG. 7 shows a case where the power supply voltage is high (for example, 400 V).
Moreover, the upper stage of FIG. 6, FIG. 7 shows the relationship between the driving | running capability (air-conditioning functional power) of an air conditioner, and the emitted-heat amount for each functional circuit with a graph, and a lower stage shows the air volume of the fan 3, and each functional circuit. The correspondence with the calorific value is shown.
In either case of FIG. 6 and FIG. 7, in the operation control by the control device 2, the air volume of the fan 3 is set to be larger as the air conditioning function force (operation capability) to be set is larger. Here, the driving ability is divided into three, “small”, “medium”, and “large”, and the air volume of the fan 3 in each operation pattern is indicated by “small”, “medium”, and “large”.

In the example shown in FIG. 6, the amount of heat generated in the A portion (rectifier circuit portion 9) and the B portion (boost circuit portion 10) increases as the driving capability increases. That is, there is a dependency relationship between the heat generation amount and the air volume, and when the heat generation amount is large, the air volume of the fan 3 also increases.
On the other hand, in the C section (inverter circuit section 11), the heat generation amount does not depend on the driving ability. This is because the current of the inverter circuit unit 11 varies depending on the motor torque of the compressor 100 and the like, and thus depends on the set temperature and the outside air temperature. That is, the heat generation amount does not depend on the air volume. For this reason, the calorific value may be “large” in the operation pattern in which the air volume is “medium” (capacity “medium”).

In the example shown in FIG. 7, the A section (rectifier circuit section 9) has a calorific value “small” when the driving capability is “small” and “medium”, and a calorific value when the driving capability is “large”. It becomes “medium”. In addition, when the driving ability is “small” and “medium”, the heat generation amount becomes “small” when the driving ability is “small”, and the heating amount greatly increases when the driving ability is “large”. "Large". Also in this example, the A portion (rectifier circuit portion 9) and the B portion (boost circuit portion 10) increase in heat generation as the driving capability increases. That is, there is a dependency relationship between the heat generation amount and the air volume, and when the heat generation amount is large, the air volume of the fan 3 also increases.
On the other hand, also in this example, the heat generation amount of the C section (inverter circuit section 11) does not depend on the driving ability. That is, the heat generation amount does not depend on the air volume. In this example, when the air volume is “medium” and “large”, the calorific value is both “medium”.

Thus, the semiconductor module 6 in the present embodiment is a C circuit (inverter circuit unit 11) that is a functional circuit whose calorific value does not depend on the driving capability, and a functional circuit that increases the calorific value as the driving capability increases. A part (rectifier circuit part 9) and B part (boost circuit part 10) are configured.
The inverter circuit unit 11 corresponds to the “first functional circuit” in the present invention. The rectifier circuit unit 9 and the booster circuit unit 10 correspond to the “second functional circuit” in the present invention.

Next, the structure of the heat sink 7 will be described.
FIG. 8 is a perspective view showing the heat sink and the semiconductor module in the first embodiment.
As shown in FIG. 8, the heat radiating plate 7 has a wide pitch portion 7b having a predetermined distance between the radiating fins at a position corresponding to the arrangement region of the C portion which is a functional circuit whose calorific value does not depend on the driving ability. Is formed. In addition, a narrow pitch portion 7a is formed at a position corresponding to the arrangement area of the A portion and the B portion, which is a functional circuit in which the amount of heat generation increases as the driving capability increases. Yes.

  The heat dissipation fins of the narrow pitch portion 7a are formed with a fin pitch of about 3 to 5 mm, for example, and can be reduced in size, and the number of fins per area is larger than that of the wide pitch portion 7b. Improvement can be expected. However, since the flow resistance of the cooling air 8 passing between the radiating fins is increased, it is necessary to secure a sufficient wind speed (for example, 2 m / s or more) to exhibit the heat radiating capacity (cooling capacity). When the wind speed is low, the cooling capacity is reduced as compared with the wide pitch portion 7b. For this reason, the fin pitch of the narrow pitch portion 7a is set such that when the air flow rate of the fan 3 is "large" and the cooling air 8 is at a high speed, the heat dissipation capability equal to or greater than that of the wide pitch portion 7b is exhibited. Is desirable.

  The heat dissipating fins of the wide pitch portion 7b are formed with a fin pitch of about 10 to 15 mm, for example, and the flow resistance of the cooling air 8 passing between the heat dissipating fins is smaller than the heat dissipating fins of the narrow pitch portion 7a. Even when the wind speed is low, it can be expected that a certain heat radiation capability (cooling capability) is exhibited. For this reason, the fin pitch of the wide pitch portion 7b is such that when the air flow rate of the fan 3 is "low" and the cooling air 8 is at a low speed, the heat dissipating ability that can dissipate the heat generated in the C portion is exhibited. It is desirable to set the fin pitch.

Next, the cooling operation of the semiconductor module 6 will be described.
FIG. 9 is a diagram illustrating a cooling operation of the semiconductor module according to the first embodiment.
FIG. 9A shows the heat generation amount and heat dissipation capability of each part when the air volume of the fan 3 is “large”, and FIG. 9B shows the heat generation of each part when the air volume of the fan 3 is “small”. The quantity and heat dissipation capacity are shown. The amount of heat generated here will be described by taking the case of FIG. 6 as an example.

As shown in FIG. 9A, when the air volume of the fan 3 is “large”, the air volume passing through the heat sink 7 also increases (hereinafter referred to as cooling air 8a). Further, in this operation pattern, the air conditioner is in a state where the operation capability is large, and as described above, the calorific value of each of the A part, the B part, and the C part is “large”. At this time, cooling air 8a having a sufficient wind speed is blown into both the narrow pitch portion 7a and the wide pitch portion 7b of the heat radiating plate 7 to cool the heat generation amount of each portion of the semiconductor module 6.
In this case, since the A part and the B part are in contact with the heat dissipation plate 7 of the narrow pitch part 7a, a sufficient heat dissipation effect can be secured, and as a result, the temperature rise of the semiconductor module 6 can be suppressed. It becomes.
In addition, as the calorific value of each part, the A part is assumed to be about 100 W, the B part is about 250 W, and the C part is assumed to be about 250 W.

As shown in FIG. 9B, when the air volume of the fan 3 is “small”, the air volume passing through the heat sink 7 is also reduced (hereinafter referred to as cooling air 8b). Further, in this operation pattern, the air conditioner is in a state where the operation capability is small, and as described above, the heat generation amount of the A part and the B part is “small”, and the heat generation amount of the C part is the set temperature or the outside air temperature. Depends on. Here, the case where the calorific value of the C section becomes “large” is considered.
At this time, the narrow pitch portion 7a of the heat radiating plate 7 cannot obtain a sufficient heat radiating effect because the cooling wind 8b has a low wind speed (for example, about 0.4 m / s). Is in a “small” state, so that the temperature does not rise excessively.
On the other hand, since the portion C is in contact with the heat dissipation plate 7 of the wide pitch portion 7b, a constant heat dissipation effect can be obtained even when the wind speed of the cooling air 8b is low, and the temperature rise is suppressed. I can do things.
In addition, as the calorific value of each part, A part assumes about 50W, B part assumes about 80W, and C part assumes about 250W.

Here, transition of the ambient temperature (outside air temperature) where the outdoor unit 1 is installed, the air conditioning function, and the heat generation amount of the semiconductor module 6 will be described.
FIG. 10 is a diagram illustrating an air conditioner operation range during the cooling operation in the first embodiment.
FIG. 11 is a diagram showing a change in the amount of heat generated at the ambient temperature and the air conditioning function in the first embodiment.
As shown in FIG. 10, the relationship between the ambient temperature of the outdoor unit and the indoor set temperature in the cooling operation is roughly determined by the ambient environment (for example, the season) in which the outdoor unit 1 is set. For example, the ambient environment is assumed to be midsummer when the outdoor unit ambient temperature and the indoor set temperature are “high temperature”. The amount of heat generated by the semiconductor module 6 is affected by the surrounding environment. That is, when the ambient temperature is high, the temperature of the cooling air 8 is also high, so that the heat radiation amount at the heat radiating plate 7 is reduced and the heat generation amount is increased.

  As shown in FIG. 11, when both the outdoor unit ambient temperature and the air conditioning function power are “low”, for example, the surrounding environment is winter, it is assumed that the temperature of the cooling air 8 is small but the temperature is low. Due to the heat radiation by the wide pitch portion 7b, the amount of heat generated in the C portion is kept small. In addition, since the driving ability is low at this time, the amount of heat generated in the A part and the B part is small.

  In addition, when the outdoor unit ambient temperature is “low” and the air conditioning function is “high”, the heat generation amount is increased in the A part and the B part, but the air volume of the cooling air 8 is large and the temperature is low. In addition, the amount of heat generated can be kept small by the heat radiation by the narrow pitch portion 7a. In addition, the heat generated by the portion C is kept small by the heat radiation by the wide pitch portion 7b.

  Further, when the outdoor unit ambient temperature is “high” and the air conditioning function is “low”, it is assumed that the temperature of the cooling air 8 is high, and all the heat generation amounts of the A part, the B part, and the C part increase. At this time, since the driving ability is low, the absolute amount of heat generated in the A part and the B part is small. Further, the heat generated by the C portion is suppressed by the heat radiation by the wide pitch portion 7b. In addition, the fin pitch of the wide pitch part 7b is good to set according to the emitted-heat amount at this time supposing the case where such ambient temperature is high.

  Further, when both the outdoor unit ambient temperature and the air conditioning function power are “high”, it is assumed that the temperature of the cooling air 8 is high, and all the heat generation amounts of the A part, the B part, and the C part increase. Since the air volume of 8 is large, the heat generation of the A part and the B part is suppressed by the heat radiation by the narrow pitch part 7a. Moreover, the calorific value of the C part is suppressed by the heat radiation by the wide pitch part 7b. Note that the fin pitch of the narrow pitch portion 7a is set according to the amount of heat generated at this time, assuming such a high ambient temperature.

The arrangement of the functional circuits of the semiconductor module 6 is not limited to the above configuration. That is, the heat radiating plate 7 is formed with a wide pitch portion 7b having a predetermined interval between the radiating fins at a position corresponding to the arrangement area of the first functional circuit, and at a position corresponding to the arrangement area of the second functional circuit. The narrow pitch portion 7a may be formed by narrowing the space between the radiating fins as compared with the wide pitch portion 7b.
For example, as shown in FIG. 12, the above-described A part, B part, and C part are arranged in a line, a narrow pitch part 7a is formed at a position corresponding to the A part and the B part, and a wide area is provided at the position corresponding to the C part. What is necessary is just to form the pitch part 7b.

  In addition, although it is also possible to combine and use the individual heat sinks having different fin pitches as the heat sink 7, the base portion of the heat sink 7 is common as in the present embodiment, and the pitch of the heat sink fin portions. Since only the base area is changed, the base area is increased, so that the thermal diffusion of the semiconductor module 6 is promoted and the heat dissipation characteristics can be improved. Note that the fin pitch can be changed relatively easily by using caulking fins or the like.

As described above, in the present embodiment, the heat radiating plate 7 has a wide pitch portion in which the distance between the heat radiating fins is a predetermined distance at a position corresponding to the arrangement region of the first functional circuit whose calorific value does not depend on the driving ability. 7b is formed. In addition, narrow pitch portions 7a are formed at positions corresponding to the arrangement region of the second functional circuit in which the amount of heat generation increases as the driving capability increases, with the radiating fins being narrower than the wide pitch portions 7b. And the control apparatus 2 controls the air volume of the fan 3 large, so that the driving capability to set is large.
For this reason, in the cooling of the semiconductor module in which a plurality of functional circuits are built in one package, appropriate cooling according to the heat generation state of each functional circuit and the air volume of the fan 3 can be performed.
Further, the narrow pitch portion 7a is formed corresponding to the second function circuit in which the heat generation amount increases as the operation capability increases, and the fan air volume increases as the operation capability increases, so the heat generation of the second function circuit by the narrow pitch portion 7a. It becomes possible to dissipate the quantity. Further, the heat sink 7 can be downsized.
Further, since a plurality of functional circuits are constituted by the semiconductor module 6 incorporated in one package and the heat sink 7 is attached to the semiconductor module 6, it is not necessary to provide a separate heat sink for each functional circuit, thereby reducing the cost. Can be achieved.

Embodiment 2. FIG.
In the first embodiment, the mode of cooling using the wind 4 generated by the fan 3 of the outdoor unit 1 has been described. In the second embodiment, a mode in which an axial fan for cooling the heat sink is provided will be described.

FIG. 13 is a perspective view showing a heat sink, a semiconductor module, and an axial fan in the second embodiment.
As shown in FIG. 13, in the present embodiment, in addition to the configuration of the first embodiment, an axial fan 21 that blows air to at least the wide pitch portion 7b and an axial fan 22 that blows air to at least the wide pitch portion 7b. And.
The axial fans 21 and 22 are disposed to face the heat radiating plate 7 (side surface side), and are driven by the control from the control device 2 to blow the cooling air 23 to the heat radiating plate 7. In addition, although the case where two axial fans are provided is described here, the present invention is not limited to this.

The axial fan 21 corresponds to the “second fan” in the present invention.
The axial fan 22 corresponds to the “third fan” in the present invention.

Next, the cooling operation of the semiconductor module 6 in the present embodiment will be described.
FIG. 14 is a diagram illustrating a cooling operation of the semiconductor module according to the second embodiment.
FIG. 14A shows the heat generation amount and heat dissipation capability of each part when the driving capability is “large”, and FIG. 14B shows the heat generation amount and heat dissipation capability of each unit when the driving capability is “small”. It shows. The amount of heat generated here will be described by taking the case of FIG. 6 as an example.

As shown in FIG. 14A, when the driving ability is “large”, as described above, the calorific value is “large” in any of the A part, the B part, and the C part. At this time, the air volume of the fan 3 of the outdoor unit 1 is also “large” and the air volume passing through the heat radiating plate 7 is also increased. However, in this embodiment, the axial flow fans 21 and 22 are driven together to further increase the heat dissipation capability. To improve. For example, when the driving capability is larger than a predetermined value (for example, “medium” or more), the control device 2 drives both the axial fans 21 and 22 to supply the cooling air 23a to the entire narrow pitch portion 7a and the wide pitch portion 7b. By supplying, heat dissipation capability is improved.
Here, the case where both the axial fans 21 and 22 are driven has been described. However, the present invention is not limited to this, and only the axial fan 22 facing the narrow pitch portion 7a may be driven. As described above, a sufficient wind speed is required to exert the heat dissipation capability of the narrow pitch portion 7a. Therefore, even if the air volume of the fan 3 of the outdoor unit 1 cannot be ensured for some reason, the semiconductor module 6 is mounted. Can be cooled.

As shown in FIG. 14B, when the driving ability is “small”, as described above, the heat generation amount of the A part and the B part is “small”, and the heat generation amount of the C part is the set temperature or the outside air temperature. Depends on. Here, the case where the calorific value of the C section becomes “large” is considered.
At this time, the air volume of the fan 3 of the outdoor unit 1 is also “small”, and the air volume passing through the heat sink 7 is also reduced. Since both the A part and the B part are in a state where the heat generation amount is “small”, the temperature does not rise excessively. On the other hand, in part C, the amount of heat generated may increase, so that the heat dissipation capability is improved by driving the axial fan 21 that faces the wide pitch part b. For example, when the air flow rate of the fan 3 is larger than a predetermined value (for example, “medium” or less), the control device 2 drives the axial fan 21 to supply the cooling air 23b to the wide pitch portion 7b, thereby improving the heat dissipation capability. Improve.

As described above, in the present embodiment, the axial flow fan 21 that is disposed to face the heat radiating plate 7 and blows air to at least the wide pitch portion 7b is provided. When the air volume of the fan 3 is smaller than the predetermined amount, the axial fan 21 is driven. For this reason, the heat dissipation capability of the wide pitch portion 7b can be improved.
Moreover, in this Embodiment, the axial flow fan 22 which is arrange | positioned facing the heat sink 7 and ventilates at least to the narrow pitch part 7a is provided. Then, the control device 2 drives the axial fan 22 when the driving capability is larger than a predetermined value. For this reason, the heat dissipation capability of the narrow pitch portion 7a can be improved.

  Further, by performing the above-described control, unnecessary operation of the axial fans 21 and 22 can be suppressed to save energy. Moreover, since it is possible to always ensure a constant wind speed by using the axial fans 21 and 22, for example, a heat radiating plate having good heat radiating characteristics using a radiating fin narrower than the fin pitch of the first embodiment. 7 can be employed, and it is possible to reduce the size of the heat sink 7 of the first embodiment.

  In the above description, the case where the driving of the axial fan is controlled by the air volume of the fan 3 and the operation capacity of the air conditioner has been described. However, the present invention is not limited to this. May be controlled. A specific example will be described with reference to FIG.

FIG. 15 is a perspective view showing a heat sink, a semiconductor module, and an axial fan provided with a temperature sensor in the second embodiment.
As shown in FIG. 15, in addition to the above configuration, an upstream temperature sensor 31 that detects the temperature on the upstream side of the wide pitch portion 7b, and a downstream temperature sensor 32 that detects the temperature on the downstream side of the wide pitch portion 7b. Prepare. The upstream temperature sensor 31 and the downstream temperature sensor 32 correspond to the “temperature sensor” in the present invention.
With such a configuration, the control device 2 drives the axial fan 21 when the temperature difference between the upstream side and the downstream side of the wide pitch portion 7b is larger than a predetermined value. As described above, when it is assumed that the temperature difference between the upstream side and the downstream side is large and the air volume from the fan 3 is small, it is possible to secure a constant wind speed by using the axial fan 21. .

  Here, the case where the temperature on the upstream side of the wide pitch portion 7b is detected has been described, but the temperature on the upstream side of the narrow pitch portion 7a is detected, and when the temperature difference is larger than a predetermined value, the axial fan 22 may be driven.

Embodiment 3 FIG.
In this embodiment, a mode in which a wide band gap semiconductor such as a silicon carbide (SiC) element is used as an internal element of a semiconductor module will be described.

  Wide band gap semiconductors such as silicon carbide elements have a higher heat resistance temperature than conventional silicon elements and can be used up to a junction temperature of the elements of up to about 200 ° C., so that the cooling conditions are eased. For example, since a critical temperature is about 100 ° C. for a silicon element, a cooling structure of 100 ° C. or lower is necessary. However, in the case of silicon carbide, a cooling effect can be expected even at 100 ° C. or higher.

  Switching elements and diode elements formed by such wide band gap semiconductors have high voltage resistance and high allowable current density, so that switching elements and diode elements can be miniaturized. By using elements and diode elements, it is possible to reduce the size of a semiconductor module incorporating these elements.

Moreover, since heat resistance is also high, the heat sink 7 can be further downsized and the semiconductor module 6 can be further downsized.
Furthermore, since the power loss is low, it is possible to increase the efficiency of the switching element and the diode element, and further increase the efficiency of the semiconductor module 6.

  In addition to the silicon carbide element, examples of the wide band gap semiconductor include a gallium nitride material and diamond.

FIG. 16 is a perspective view showing a heat sink and a semiconductor module in the third embodiment.
In the example shown in FIG. 16, the case where a silicon carbide element is used for the B part (boost circuit part 10) is shown.
As described above, the silicon carbide element has a high heat-resistant temperature and can relax the cooling condition. Therefore, the silicon carbide element can be arranged on the leeward side of the air blowing from other functional circuits.
For this reason, as shown in FIG. 16, the mounting direction of the semiconductor module 6 is rotated by 180 degrees from the first embodiment (FIG. 8).
In this case, the high temperature wind is blown to the B part by the heat discharged from the A part. However, since part B uses a silicon carbide element, it has sufficient heat resistance and does not break even in a high temperature environment.

  In this way, when considering a cooling structure that combines silicon elements and silicon carbide elements, it is possible to design heat dissipation by taking advantage of the characteristics of silicon carbide by placing silicon elements on the windward side and silicon carbide elements on the leeward side. It becomes.

  When a wide band gap semiconductor such as a silicon carbide element is used as a part of a plurality of functional circuits constituting the semiconductor module 6, the wide band gap semiconductor is selected according to the operation pattern of the air conditioner and the heat generation amount of each functional circuit. It is recommended to select a functional circuit using. A specific example is shown in FIG.

FIG. 17 is a diagram illustrating a selection example of a functional circuit to which the silicon carbide element according to the third embodiment is applied.
Note that the operation pattern and the module heat generation amount in FIG. 17 correspond to the relationship between the operation pattern shown in FIGS. 6 and 7 and the heat generation amount of each functional circuit.
In the example of FIG. 17A, the operation pattern in which the calorific value of part C is “large” when the air volume is “medium” and “large” and the calorific value is larger than that of parts A and B is shown in FIG. Many. In this example, a silicon carbide element is applied to the C portion where the heat generation state increases.
In the example of FIG. 17 (B), the heat generation amount is “medium” when the air volume is “medium” and “large” in part C, and the heat generation amount is low in part B when the air flow is “small” and “medium”. Although both are “small”, the calorific value is “large” when the air volume is “large”. In this example, a silicon carbide element is applied to the portion B where the heat generation amount is the largest.

  Note that the example of selection of the functional circuit to which the silicon carbide element is applied shown in FIG. 17 is an example, and is not limited thereto, and may be appropriately selected depending on design conditions, cost, and the like.

  A wide bandgap semiconductor such as a silicon carbide element may be used for all the functional circuits constituting the semiconductor module 6.

  In the first to third embodiments, the case where the semiconductor module 6 is mounted on the outdoor unit 1 has been described. However, the present invention is not limited to this and may be mounted on the indoor unit. Even in this case, the control device 2 can achieve the same effect by increasing the air volume of the fan of the indoor unit as the operating capacity to be set is larger.

  DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Control apparatus, 3 Fan, 4 wind, 6 Semiconductor module, 7 Heat sink, 7a Narrow pitch part, 7b Wide pitch part, 8 Cooling air, 9 Rectifier circuit part, 10 Booster circuit part, 11 Inverter circuit part , 12 Other circuit units, 21 Axial fan, 22 Axial fan, 23 Cooling air, 31 Upstream temperature sensor, 32 Downstream temperature sensor, 100 Compressor, 101 Four-way valve, 102 Outdoor heat exchanger, 103 Expansion valve , 104 Indoor heat exchanger.

Claims (8)

In an air conditioner in which a compressor, a condenser, an expansion means, and an evaporator are connected by a refrigerant pipe and a refrigerant circuit for circulating the refrigerant is formed.
A fan that is provided in a housing on which the condenser or the evaporator is mounted, and blows air to the condenser or the evaporator;
A controller for controlling the compressor and the fan according to the operating capacity to be set,
The controller is
A semiconductor module in which a plurality of functional circuits are divided into arrangement areas and incorporated in one package;
A heat sink attached to the semiconductor module and formed with heat dissipating fins through which a part of the fan air flows;
At least some of the plurality of functional circuits are configured by a first functional circuit whose calorific value does not depend on the driving capability, and a second functional circuit whose calorific value increases as the driving capability increases,
The heat sink is
A wide pitch portion having a predetermined interval between the heat dissipating fins is formed at a position corresponding to the arrangement region of the first functional circuit,
At a position corresponding to the arrangement area of the second functional circuit, a narrow pitch portion is formed by narrowing the interval between the heat radiation fins than the wide pitch portion,
The air conditioner characterized in that the control device increases the air volume of the fan as the operating capacity to be set increases. The fan and the control device are arranged in an outdoor unit,
The first functional circuit is configured by an inverter circuit that varies the rotational speed of the compressor,
2. The air conditioner according to claim 1, wherein the second functional circuit includes at least one of a rectifier circuit and a booster circuit that supply DC power to the inverter circuit. A second fan that is disposed to face the heat sink and blows air to at least the wide pitch portion;
The controller is
The air conditioner according to claim 1 or 2, wherein when the air volume of the fan is smaller than a predetermined amount, the second fan is driven. A second fan that is disposed to face the heat sink and blows air to at least the wide pitch portion;
A temperature sensor for detecting an upstream temperature and a downstream temperature of the wide pitch portion through which the air flows;
The controller is
The air conditioner according to claim 1 or 2, wherein the second fan is driven when a temperature difference between the upstream side and the downstream side of the wide pitch portion is larger than a predetermined value. A third fan that is disposed opposite to the heat sink and blows air to at least the narrow pitch portion;
The controller is
The air conditioner according to any one of claims 1 to 4, wherein the third fan is driven when the driving capability is greater than a predetermined value. The air conditioner according to any one of claims 1 to 5, wherein the semiconductor module is formed of a wide band gap semiconductor. The part of the plurality of functional circuits is formed of a wide band gap semiconductor, and is disposed on the leeward side of the air blowing from the other functional circuits. Air conditioner. The wide band gap semiconductor is
The air conditioner according to claim 6 or 7, wherein the air conditioner is silicon carbide, gallium nitride-based material, or diamond.

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