JP6554894B2 - Electrical component cooling system - Google Patents

Description

  The present invention relates to a cooling system for electrical components, and more particularly, to a configuration using a variable conductance heat pipe.

  Conventionally, as a cooling system for electrical components, for example, there is one disclosed in Patent Document 1. This cooling system employs a configuration including a variable conductance heat pipe so as to keep the temperature of the electrical component within a certain temperature range so that condensation does not occur in the electrical component.

  Specifically, the cooling system includes a variable conductance heat pipe in which a non-condensable gas is mixed together with a refrigerant (working fluid), and the heat pipe is disposed in a horizontal direction, and a transistor or the like is disposed in an evaporation portion of the heat pipe. While arranging electrical parts, a configuration is adopted in which cooling water is circulated around the condensing part of the heat pipe. In this configuration, the heat of the electrical component is transmitted from the evaporation portion of the heat pipe to the condensation portion to dissipate heat to the cooling water, and the electrical component is cooled with the cooling water. In the heat pipe, the effective heat transfer area of the condensing part is adjusted by the mixed non-condensable gas in accordance with the temperature of the working fluid inside, and the temperature of the evaporating part is kept within a certain temperature range. As a result, even when the cooling water temperature is equal to or lower than the dew point of the ambient air, the temperature of the electric component is kept above the dew point so that the electric component does not cause dew condensation.

  In addition, as a specific configuration of a variable conductance heat pipe mixed with non-condensable gas, in Patent Documents 2 and 3, conventionally, a cylindrical heat pipe is horizontally placed, for example, an evaporating part at the left end and a condensing part at the right end. And a gas reservoir for storing non-condensable gas is disposed on the opposite side of the condensing unit from the evaporation unit. Further, in Patent Document 4, the heat pipe has a panel shape (planar type), a heat generator is attached to one end thereof, and an attachment portion of the heat generator is used as an evaporation portion, while a condensing portion is disposed at the other end. A tank (gas reservoir) in which non-condensable gas is accumulated is disposed on the opposite side of the condensing unit from the evaporation unit.

Japanese Utility Model Publication No. 61-182092 JP-A-10-122775 JP 59-180283 A JP-A-5-126480

  By the way, in the refrigeration apparatus, as a cooling configuration of electrical components such as a power module that controls a compressor or the like, it is conceivable to use the variable conductance heat pipe to cool the electrical components with the refrigerant in the refrigerant circuit.

  However, in each of the techniques of Patent Documents 1-4, the heat pipe is placed horizontally, the evaporation part is disposed at one end thereof, the condensing part is disposed at the other end, and the gas is disposed on the opposite side of the condensing part from the evaporation part. It is the structure which has arrange | positioned the reservoir part and the tank. For this reason, there is a drawback that it is long in the horizontal direction and difficult to downsize, and it is expensive. Further, a gas reservoir and a tank for non-condensable gas are essential, and there is a disadvantage that the size is increased by arranging the gas reservoir and the tank.

  SUMMARY OF THE INVENTION In view of the above, the present invention aims to cool an electrical component satisfactorily even in a case where a gas reservoir or a tank in which non-condensable gas is accumulated is not disposed in a cooling system for an electrical component of a refrigeration apparatus. On the other hand, it is to reduce the size of the electrical component cooling system.

  In order to achieve the above object, in the present invention, a heat transfer section as a variable conductance heat pipe is provided, and the heat transfer section is arranged in a standing state so that the flow direction of the internal working fluid is set to the up and down direction. An evaporating part and a condensing part are arranged in the direction. Furthermore, the structure which makes noncondensable gas act on both the said evaporation part and a condensation part inside a heat conveyance part is employ | adopted.

That is, the first invention is a cooling system for electrical components of a refrigeration apparatus (1) having a refrigerant circuit (10), which is arranged in an upright state and has a plate-like shape in which a working fluid (F) is enclosed. A heat transfer section (90, 100) and a heat exchanger (80) to which the refrigerant flowing through the refrigerant circuit (10) is supplied. Inside the heat transfer section (90, 100), the working fluid (F) An evaporation section (91) for cooling the electrical component by evaporation and a condensing section (92) for condensing the working fluid (F) by the refrigerant supplied to the heat exchanger (80) are partitioned in the horizontal direction. And a gas passage for connecting the upper part of the evaporator (91) and the upper part of the condenser (92) to guide the gaseous working fluid (F) of the evaporator (91) to the condenser (92). (94) is formed in the inside of the heat transport part (90, 100), the working fluid (F) with non-condensable gas (N) is sealed, the non Condensation gas (N) is in a state of standing the heat transport part (90, 100), characterized in that it is a specific gravity such as to be located above the gas passage (94) within.

  In the first aspect of the invention, the working fluid flows in the vertical direction inside the heat transfer section arranged in an upright state. And since the evaporation part and the condensation part are arranged in the horizontal direction inside the heat transfer part in the standing state, the heat transfer part has a vertical length as compared with the heat pipe arranged long in the conventional horizontal direction. The difference from the lateral length can be shortened, and the overall size can be reduced.

  In addition, since the evaporating part and the condensing part are arranged side by side in the horizontal direction, the gaseous working fluid that has evaporated from the electrical components in the evaporating part flows laterally from the upper part of the evaporating part through the gas passage. Then, it flows into the upper part of the condensing part, and then, in the condensing part, it dissipates heat and condenses to the refrigerant in the refrigerant circuit, and becomes liquid and flows downward of the condensing part. Here, non-condensable gas is enclosed in the heat transfer section. This non-condensable gas is located in at least the central portion of the upper portion of the heat transfer section in an upright state, that is, in the gas passage. Therefore, since the working fluid is located between the upper part of the evaporation part and the upper part of the condensation part and acts on the evaporation part and the condensation part, compared with the case of acting only on the conventional condensation part, the evaporation part And the ability to maintain the temperature of the electrical component within a predetermined temperature range is improved. Moreover, since no gas reservoir or tank is required as in the prior art, it is possible to reduce the size accordingly.

According to a second aspect of the present invention, in the electrical component cooling system, the non-condensable gas (N) is located in the gas passage (94) in the heat transfer section (90, 100), and the working fluid (F) As the temperature drops, the volume increases, and the amount of inflow into the upper part of the evaporation unit (91) and the amount of inflow into the upper part of the condensing unit (92) increase.

  In the second aspect of the invention, when the temperature of the working fluid rises, the non-condensable gas is compressed by the gaseous working fluid in accordance with the temperature rise, and the volume ratio of the gaseous working fluid relatively increases significantly. Therefore, the heat transfer unit is not significantly affected by the presence of the non-condensable gas and functions as a heat pipe. On the contrary, when the temperature of the working fluid decreases, the volume of the non-condensable gas increases in accordance with the temperature decrease, and a part of the non-condensable gas flows into the condensing part and acts on the condensing part. Can no longer operate. In the evaporating part, the working fluid cannot be lowered to the evaporating pressure by the pressure of the non-condensed gas whose volume has been increased, and the evaporating part is difficult to operate. Therefore, when the types and amounts of both the working fluid and the non-condensable gas are appropriately selected, the heat transfer section functions as a variable conductance heat pipe, and the temperature of the evaporation section and the electrical equipment is set to a predetermined value while cooling the electrical equipment satisfactorily. It is possible not to drop below the temperature.

  According to a third aspect of the present invention, in the cooling system for electrical components, the amount of the non-condensable gas (N) present in the heat transfer section (100) is determined by opening the heat transfer section (100). It has the non-condensable gas storage part (110) to adjust.

  In the third aspect of the invention, since the amount of non-condensable gas can be increased, the increase / decrease change amount of non-condensable gas existing inside the heat transfer section can be greatly changed, so that the temperature controllability of the electrical component is improved. Further, when the heat transfer unit functions as a heat pipe, all of the non-condensable gas can be pushed into the non-condensable gas storage unit, and the non-condensable gas can be prevented from interfering with the operation of the heat pipe.

  According to a fourth aspect of the present invention, in the electrical component cooling system, the temperature of the non-condensable gas (N) stored in the non-condensable gas storage unit (110) is adjusted to an outside air temperature.

  In the fourth aspect of the invention, when the outside air temperature is high, the operating temperature at which the heat transfer section functions as a heat pipe can be increased. Therefore, even when the outside air temperature is high and the dew point is high, the temperature of the electrical component Can be controlled to a temperature equal to or higher than the dew point, and dew condensation of the electrical equipment can be reliably prevented.

  According to a fifth aspect of the present invention, in the electrical component cooling system, the heat transfer section (90, 100) is connected with a lower portion of the evaporation section (91) and a lower section of the condensing section (92). A liquid passage (95) for guiding the liquid working fluid (F) of the section (92) to the evaporation section (91) is formed.

  In the fifth aspect of the invention, in the plate-like heat transfer section, the working fluid takes heat from the electrical components in the evaporation section and becomes gaseous, and passes from the upper portion of the evaporation section to the upper portion of the condensing section through a horizontal gas passage. It flows in, condenses by radiating heat to the refrigerant in the refrigerant circuit at the condensing part, flows into the lower part of the evaporating part through the horizontal liquid passage from the lower part, and takes the heat from the electrical components again at this evaporating part to form a gaseous state Repeat to become. Therefore, even if it is a plate-shaped heat conveyance part, a heat medium can be circulated up and down, and a plate-shaped heat conveyance part can be favorably functioned as a heat pipe.

  According to a sixth aspect of the present invention, in the cooling system for electrical components, the electrical component is a power element (63) of a power converter (60).

  In the sixth aspect of the invention, it is reliably prevented that the temperature of the power element of the power conversion device becomes lower than the predetermined temperature to cause dew condensation.

  According to the electrical component cooling system of the first aspect of the invention, the plate-like heat transfer section as the variable conductance heat pipe can be made compact. Moreover, it can function as a variable conductance heat pipe without arranging a gas reservoir or a tank for non-condensable gas.

  According to the second invention, since the non-condensable gas is located in the gas passage between the upper part of the evaporation part and the upper part of the condensation part, the non-condensable gas is caused to act on both the evaporation part and the condensing part. In addition, it is possible to reliably prevent the temperature of the electrical component from decreasing below a predetermined temperature.

  According to the third aspect of the invention, since the non-condensable gas storage portion is disposed, the size of the non-condensable gas storage portion is increased, but the function as a variable conductance heat pipe can be improved.

  According to the fourth invention, even when the outside air temperature is high and the dew point is high, the dew condensation of the electrical equipment can be reliably prevented.

  According to 5th invention, even if it is a plate-shaped heat conveyance part, it is possible to circulate a heat medium to an up-down direction, and to function a plate-shaped heat conveyance part favorably as a heat pipe.

  According to the sixth aspect, it is possible to reliably prevent condensation of the power element of the power conversion device.

FIG. 1 is a diagram showing a refrigerant circuit of an air conditioner to which the electrical component cooling system according to the present embodiment is applied. FIG. 2 is a schematic cross-sectional view of the outdoor unit according to the first embodiment. FIG. 3 is a plan view of the refrigerant jacket. FIG. 4 is a view showing a longitudinal section of the heat pipe. FIG. 5 is a view showing a longitudinal section of a heat pipe according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

<< First Embodiment of the Invention >>
Below, the air conditioner (1) to which the electrical component cooling system (70) which concerns on the 1st Embodiment of this invention is applied is demonstrated. The air conditioner (1) has a refrigerant circuit (10) and performs switching between a cooling operation and a heating operation. This air conditioner (1) has an indoor unit (20) installed indoors and an outdoor unit (30) installed outdoor. The indoor unit (20) and the outdoor unit (30) are connected to each other by the two connecting pipes (11, 12), so that the refrigerant circuit (10) serving as a closed circuit is configured. The refrigerant circuit (10) is filled with refrigerant. As the refrigerant circulates in the refrigerant circuit (10), a vapor compression refrigeration cycle is performed. FIG. 1 shows a refrigerant circuit (10) of an air conditioner (1) to which the electrical component cooling system (70) according to the present embodiment is applied.

<Indoor unit (20)>
As shown in FIG. 1, the indoor unit (20) has an indoor heat exchanger (21), an indoor fan (22), and an indoor expansion valve (23). The indoor heat exchanger (21) is constituted by, for example, a cross fin type fin-and-tube heat exchanger. In the indoor heat exchanger (21), heat is exchanged between the refrigerant flowing inside the heat transfer tube and the air blown by the indoor fan (22). The indoor expansion valve (23) is composed of, for example, an electronic expansion valve.

<Outdoor unit (30)>
The outdoor unit (30) includes an outdoor heat exchanger (31), an outdoor fan (32), an outdoor expansion valve (33), a compressor (34), a four-way switching valve (35), a power converter (60), and electrical equipment. Product cooling system (70). The outdoor heat exchanger (31) is constituted by, for example, a cross fin type fin-and-tube heat exchanger. In the outdoor heat exchanger (31), heat is exchanged between the refrigerant flowing inside the heat transfer tube and the air blown by the outdoor fan (32). The outdoor expansion valve (33) is composed of, for example, an electronic expansion valve. The compressor (34) is composed of a rotary compressor such as a scroll compressor. The four-way switching valve (35) has first to fourth ports, and switches the refrigerant circulation direction in the refrigerant circuit (10). In this example, the four-way switching valve (35) is in a state in which the first port and the second port communicate with each other and the third port and the fourth port communicate with each other during the cooling operation (state indicated by a solid line in FIG. 1). Sometimes the first port and the third port are communicated and the second port and the fourth port are communicated (shown by a broken line in FIG. 1).

  FIG. 2 is a schematic cross-sectional view of the outdoor unit (30) according to the embodiment. As shown in FIG. 2, the outdoor unit (30) has a box-shaped casing (40). The casing (40) has a front panel (41), a rear panel (42), a first side panel (43), and a second side panel (44). The front panel (41) is provided on the front side of the outdoor unit (30). The front panel (41) is formed with a suction port (41a) through which outdoor air is sucked. The front panel (41) is configured to be detachable from the main body of the casing (40). The rear panel (42) is provided on the rear side of the outdoor unit (30). The rear panel (42) is formed with an outlet (42a) through which outdoor air is blown out. The first side panel (43) is provided on one end of the outdoor unit (30) in the width direction (the direction indicated by the arrow X in FIG. 2). An air outlet (43a) is formed in the first side panel (43). The second side panel (44) is provided on the other end side in the width direction of the outdoor unit (30).

  Moreover, the casing (40) has a vertical partition plate (45) and a horizontal partition plate (46). The internal space of the casing (40) is partitioned into two spaces in the width direction by the vertical partition plate (45). Among these spaces, the space on the first side panel (43) side is a heat exchanger chamber (47) that houses the outdoor heat exchanger (31). Of these spaces, the space on the second side panel (44) side is further divided into two spaces on the front and rear sides by the horizontal partition plate (46). Of the two front and rear spaces, the rear space is a compressor chamber (48) that houses the compressor (34), and the front space is an electrical component chamber (49) that houses electrical components. The electrical component room (49) has an opening (hereinafter referred to as service opening (41b)) on the front panel (41) side.

  Specifically, as shown in FIG. 2, a power conversion device (60) and an electrical component cooling system (70) are accommodated in the electrical component room (49). The power converter (60) supplies power to the motor of the compressor (34). In this power converter (60), electrical components such as a plurality of power elements (63) are mounted on a printed circuit board (61). The power element (63) of the present embodiment is a switching element (for example, IGBT or MOSFET) of an inverter circuit (not shown). That is, the power element (63) is a heat generating component that generates a lot of heat during operation (during the operation of the compressor (34)). In order to operate the air conditioner (1) normally, It is necessary to cool the element (63) so as not to exceed an operable temperature (for example, 90 ° C.). In the present embodiment, the power element (63) is cooled by the electrical component cooling system (70).

<Electrical component cooling system>
The electrical component cooling system (70) includes a refrigerant jacket (80) and a heat pipe (90).

-Refrigerant jacket (80)-
FIG. 3 is a plan view of the refrigerant jacket (80). The refrigerant jacket (80) of the present embodiment includes a main body (80b) and a cooling pipe (15). The main body (80b) has a flat rectangular parallelepiped shape, and is formed of a metal such as aluminum. As shown in FIG. 3, the main body (80b) is provided with two through holes (80a), and a cooling pipe (15) is inserted into these through holes (80a). Specifically, the cooling pipe (15) passes through one through-hole (80a), then turns back into a U shape, and passes through the other through-hole (80a).

  In addition, the cooling pipe (15) is configured by using a part of the refrigerant pipe constituting the refrigerant circuit (10), and in this embodiment, the cooling pipe (15) is a copper pipe. In this embodiment, the cooling pipe (15) is connected to a high-pressure liquid line in the refrigerant circuit (10), and the cooling pipe (15) is connected to the high-pressure liquid line after being condensed by the heat exchanger (21, 31). Liquid refrigerant circulates. That is, the refrigerant jacket (80) is supplied with the refrigerant flowing through the refrigerant circuit (10) (the refrigerant used in the refrigeration cycle) by the cooling pipe (15), and the refrigerant jacket (80) is the heat in the present invention. It is an example of an exchanger.

-Heat pipe (90)-
FIG. 4 shows a longitudinal section of the heat pipe (90). The heat pipe (90) is arranged in a vertically standing state, and conveys heat by the working fluid (F) sealed inside evaporating and condensing (phase change). That is, the heat pipe (90) is an example of the heat transfer unit of the present invention.

  As shown in FIG. 4, the heat pipe (90) has a plate-like form. In this example, the heat pipe (90) is formed by joining two metal plates (90a) facing each other. In the present embodiment, these metal plates (90a) are aluminum plates.

  In the heat pipe (90), one of these metal plates (90a) is partially formed with a portion (bulging portion) that swells on the opposite side of the mating surface of the mating metal plate (90a). Thus, a cavity for enclosing the working fluid (F) is formed between the metal plates (90a). Such a cavity can be formed by, for example, a roll bond method. The working fluid (F) in the heat pipe (90) is, for example, lithium, naphthalene, methanol, ammonia or the like.

  In this heat pipe (90), a non-swelled portion (referred to as a partitioning portion (93)) is provided in the vertical direction at the substantially central portion of the metal plate (90a), so that it can be moved left and right as shown in FIG. Two side-by-side cavities are formed. The left cavity shown in FIG. 4 is an evaporation section (91) described later, and the right cavity is a condensation section (92) described later. In the evaporation section (91), a plurality of wall sections (91b) are provided in the vertical direction, thereby partitioning the inside as a plurality of narrow flow paths (91a). Similarly, a plurality of wall portions (92b) are also provided in the condensing portion (92) in the vertical direction, and the inside is partitioned as a plurality of narrow flow paths (92a).

  Further, in the heat pipe (90), a hollow portion extending in the lateral direction is formed to connect the upper portion of the evaporation portion (91) and the upper portion of the condensing portion (92). As will be described later, the hollow portion that connects the upper portions is used as a gas passage (94) for guiding the working fluid (F) that has become gaseous in the evaporation portion (91) to the condensing portion (92). In this example, the upper end of the condensing unit (92) is higher than the upper end of the evaporating unit (91), and the gas passage (94) is inclined upward from the evaporating unit (91) toward the condensing unit (92). It has become.

  The heat pipe (90) is also formed with a laterally extending cavity that connects the lower part of the evaporator (91) and the lower part of the condenser (92). As will be described later, the hollow portion connecting the lower portions is used as a liquid passage (95) for guiding the working fluid (F) that has become liquid in the condensing unit (92) to the evaporating unit (91). In this example, the lower end of the condensing unit (92) is higher than the lower end of the evaporating unit (91), and the liquid passage (95) is inclined downward from the condensing unit (92) toward the evaporating unit (91). It has become.

  And in the said heat pipe (90), the non-condensable gas (N) is enclosed with the working fluid (F). The amount of the non-condensable gas (N) enclosed is smaller than the amount of the working fluid (F) enclosed. Examples of the non-condensable gas (N) include nitrogen, helium, argon, and xenon.

  The non-condensable gas (N) enclosed with the working fluid (F) in the heat pipe (90) is placed in a state where the heat pipe (90) is erected, so the specific gravity in the heat pipe (90) When the volume is large, it flows also into the upper part of the evaporation part (91) and the upper part of the condensing part (92).

  On the outer surface of the heat pipe (90), an area for fixing the electrical component (here, the power element (63)) is provided at a location corresponding to the evaporation section (91). More specifically, a flat surface (A) for contacting the plurality of power elements (63) is formed. In addition, a refrigerant jacket (80) is fixed to a location corresponding to the condensing part (92) on the outer surface of the heat pipe (90). Therefore, the flat surface (B) of the width corresponding to the main-body part (80b) of a refrigerant | coolant jacket (80) is formed in the part which fixes a refrigerant | coolant jacket (80).

  The electrical component cooling system (70) is incorporated in the outdoor unit (30) of the air conditioner (1). Various procedures can be considered for incorporation, but the following is given as an example.

  First, the heat pipe (90) is fixed in advance to the power element (63) mounted on the printed circuit board (61). In order to fix the heat pipe (90) to the power element (63), for example, a screw hole or a bracket is provided in the heat pipe (90), and the heat pipe (90) is screwed to the printed circuit board (61). It is done.

  The refrigerant jacket (80) is incorporated in the outdoor unit (30), and the cooling pipe (15) is connected to the refrigerant circuit (10).

  Then, the printed circuit board (61) to which the heat pipe (90) is attached is inserted into the outdoor unit (30) from the service opening (41b), and the refrigerant jacket (80) is fixed to the heat pipe (90). As specific fixing means, it is conceivable to fix the refrigerant jacket (80) and the heat pipe (90) by screwing them together. It is desirable to apply thermal conductive grease between the heat pipe (90) and the power element (63) or between the heat pipe (90) and the refrigerant jacket (80).

<Cooling of electrical components in the air conditioner (1)>
In the air conditioner (1), the cooling operation and the heating operation are switched. For example, in the cooling operation, the refrigerant compressed by the compressor (34) is condensed by the outdoor heat exchanger (31). For example, the condensed refrigerant passes through the fully-expanded outdoor expansion valve (33) and flows through the cooling pipe (15). During operation of the compressor (34), electric power is supplied from the power converter (60) to the compressor (34), and at that time, the power element (63) generates heat and its temperature rises.

  In the heating operation, the refrigerant compressed by the compressor (34) is condensed by the indoor heat exchanger (21). Thereby, indoor air is heated. The condensed refrigerant passes through the fully expanded indoor expansion valve (23), for example, and flows through the cooling pipe (15). Even in the heating operation, power is supplied from the power conversion device (60) to the compressor (34), and at that time, the power element (63) generates heat and the temperature rises.

  Thus, the power element (63) that generates heat in the cooling operation or the heating operation is cooled by the electrical component cooling system (70).

  First, while the air conditioner (1) is stopped, the working fluid (F) in the heat pipe (90) is in a liquid state and is accumulated below the heat pipe (90). In this example, it is assumed that the level of the working fluid (F) is in the middle of the evaporation section (91) while the air conditioner (1) is stopped. FIG. 4 schematically shows the liquid level of the working fluid (F) during the stop.

  When the power converter (60) operates and the temperature of the power element (63) rises, the working fluid (F) accumulated in the evaporation section (91) is evaporated by the heat of the power element (63). That is, bubbles of the working fluid (F) are generated in the narrow channel (91a) of the evaporation section (91), and the gaseous working fluid (F) and the liquid working fluid are generated in the narrow channel (91a). (F) is mixed. Since the heat pipe (90) is arranged vertically, the bubbles in the narrow channel (91a) rise upward in the narrow channel (91a) by the buoyancy. It flows out from the upper end of the narrow channel (91a). At this time, in the present embodiment, bubbles (gaseous working fluid (F)) rising in the narrow flow path (91a) are operated in a liquid state in the liquid passage (95) or near the lower portion of the evaporation section (91). The fluid (F) is efficiently lifted upward into the evaporation section (91).

  The gaseous working fluid (F) exiting from the upper end of the narrow channel (91a) is introduced into the condensing part (92) through the gas passage (94). Since the upper end of the condensing part (92) is higher than the upper end of the evaporating part (91), the gaseous working fluid (F) in the gas passage (94) can easily reach the upper part of the condensing part (92). Can flow in.

  In the heat pipe (90), since the refrigerant jacket (80) is fixed to the outside of the condensing part (92), the gaseous working fluid (F) entering the condensing part (92) (80) will dissipate heat. That is, the heat pipe (90) carries the heat of the power element (63) to the refrigerant jacket (80).

  The heat of the refrigerant jacket (80) is transmitted to the cooling pipe (15) while spreading to the main body (80b), and further to the refrigerant in the cooling pipe (15). As a result, the power element (63) is cooled, and the power element (63) is maintained at a predetermined operable temperature. During the cooling operation, the refrigerant flowing through the cooling pipe (15) is depressurized by the indoor expansion valve (23) and then evaporated by the indoor heat exchanger (21). Further, during the heating operation, the refrigerant flowing through the cooling pipe (15) is depressurized by the outdoor expansion valve (33) and then evaporated by the outdoor heat exchanger (31).

  Then, the working fluid (F) that has radiated heat to the refrigerant jacket (80) in the condensing unit (92) condenses and becomes liquid. The working fluid (F) in the narrow channel (92a) flows downward in the narrow channel (92a) due to gravity, and flows out from the narrow channel (92a) to the liquid passage (95). In the present embodiment, the liquid working fluid (F) flowing in the narrow flow path (92a) converts the gaseous working fluid (F) in the gas passage (94) or near the upper portion of the condensing section (92) to the condensing section. (92) Demonstrates the effect of being efficiently pulled into.

  The working fluid (F) in the liquid passage (95) is pushed by the working fluid (F) continuously flowing from the condensing part (92) and introduced into the evaporation part (91). Since the lower end of the condensing unit (92) is higher than the lower end of the evaporating unit (91), the liquid working fluid (F) can easily flow into the evaporating unit (91).

  As described above, in the electrical component cooling system (70), the working fluid (F) circulates in the heat pipe (90) while changing the phase in the heat pipe (90), and the heat of the power element (63) is obtained. It is conveyed to the refrigerant jacket (80).

<Action of non-condensable gas>
The non-condensable gas (N) enclosed in the heat pipe (90) transports heat of the power element (63) to the refrigerant jacket (80) by the working fluid (F) to cool the power element (63). While ensuring the function, the power element (63) functions so as not to be cooled too much below a predetermined temperature (t0) to prevent the power element (63) from condensing.

  Specifically, when the power element (63) is higher than the predetermined temperature (t0), the saturation pressure of the working fluid (F) is exponential due to its characteristics as the temperature of the working fluid (F) increases. Suddenly rises. On the other hand, the non-condensable gas (N) has only a slight pressure increase compared to the pressure increase of the working fluid (F) because the pressure increase due to the temperature increase is proportional to the absolute temperature due to its characteristics. As a result, the non-condensable gas (N) is compressed and reduced in volume by the gaseous working fluid (F), and the volume ratio of the gaseous working fluid (F) to the non-condensable gas (N) is greatly increased. Therefore, the working fluid (F) is not significantly affected by the presence of the non-condensable gas (N) and transports the heat of the power element (63) from the evaporation section (91) to the condensing section (92) to form a refrigerant jacket. Since it is transmitted well to (80), the function as a heat pipe is secured.

  On the other hand, when the temperature of the working fluid (F) decreases, the saturated vapor pressure of the working fluid (F) suddenly decreases, so that the non-condensable gas (N) expands and the volume increases, and the non-condensable gas (N) Expands from the gas passage (94) to the upper part of the condensing part (92) and below it to cover these parts. As a result, it is difficult to condense the working fluid (F) in the condensing unit (92). Further, the expanded non-condensable gas (N) is located up to and below the evaporation section (91) and covers these parts, so the working fluid (F) present in the evaporation section (91) is The pressure of the non-condensable gas (N) cannot be reduced to the evaporating pressure, making it difficult to evaporate, and the evaporating performance of the working fluid (F) in the evaporating section (91) is reduced. As a result, the heat pipe (90) becomes difficult to function as a heat pipe for cooling the power element (63).

  Due to the action of the non-condensable gas (N), in this embodiment, the type of the working fluid (F) is used so that the temperature of the evaporation section (91) to which the power element (63) is fixed does not drop below a predetermined temperature. The heat pipe (90) is made to function as a variable conductance heat pipe by appropriately selecting the amount and amount and the type and amount of the non-condensable gas (N).

(Effect of this embodiment)
In the present embodiment, in the heat pipe (90) used in an upright state, the evaporator (91) and the condenser (92) are arranged side by side in the horizontal direction, so the heat pipe (90) A quadrangular shape with little difference between the vertical length and the horizontal length can be obtained. Therefore, the heat pipe (90) can be made compact as compared with the conventional shape that is long in one direction (lateral direction).

  In the standing heat pipe (90), the working fluid (F) gasified in the evaporation section (91) flows from the upper portion of the evaporation section (91) to the gas passage (94 ) And then flows into the upper part of the condensing part (92). And after that, it repeats flowing into the lower part of an evaporation part (91) from the lower part of the condensation part (92) via the liquid channel (95) located in the horizontal direction. Thus, since the working fluid (F) circulates in the vertical direction and the flow of the working fluid (F) is smooth, the heat of the power element (63) can be satisfactorily transmitted to the refrigerant jacket (80).

  Furthermore, since the non-condensable gas (N) is enclosed with the working fluid (F) inside the heat pipe (90) used in the standing state, the non-condensing gas is contained in the standing heat pipe (90). (N) is located in the gas passage (94) at the top of the heat pipe (90), and when the temperature of the working fluid (F) decreases, the evaporation section is located in the lateral direction of the gas passage (94) by volume expansion (91) acts on both the condensing part (92) and reduces the functions of both the evaporating part (91) and the condensing part (92), so that the temperature of the power element (63) does not fall below a predetermined temperature. Therefore, it is possible to reliably control the dew condensation of the power element (63) as an electrical component of the refrigeration apparatus.

  In addition, since it can function as a variable conductance heat pipe without the need for a conventional non-condensable gas reservoir or tank, further downsizing is possible.

(Second Embodiment of the Invention)
FIG. 5 shows a second embodiment of the present invention.

  In the present embodiment, a non-condensable gas reservoir is further provided in the configuration of the heat pipe (90) of the first embodiment.

  Specifically, in the heat pipe (100) of FIG. 5, a non-condensable gas reservoir (non-condensable gas reservoir) (110) having a quadrangular cross section is disposed above the gas passage (94). The non-condensable gas reservoir (110) stores non-condensable gas therein, and is opened through a slit (110a) above the condensing unit (92).

  The non-condensable gas reservoir (110) is insulated from the condensing part (92), the gas passage (94) and the evaporation part (91) by the slit (110a), and the outer wall part is exposed to the outside air. Yes. Accordingly, the temperature of the non-condensable gas reservoir (110) is approximately equal to the temperature of the outside air.

<Operation of non-condensable gas reservoir (110)>
In the present embodiment, the amount of non-condensable gas in the heat pipe (100) is greatly increased by the non-condensable gas stored in the non-condensable gas reservoir (110). Therefore, the action of the non-condensable gas is basically the same as that of the first embodiment, but a part of the non-condensable gas located in the gas passage (94) is non-condensed according to the pressure of the working fluid (F). The amount of non-condensable gas that enters and exits the gas reservoir (110) and adjusts the amount of non-condensable gas present inside the heat pipe (100), greatly changing the evaporation performance of the evaporation section (91) and the condensation performance of the condensation section (92) It is possible to improve the temperature controllability of the power element (63).

  In addition, when the heat pipe (100) is operating as a heat pipe for cooling the power element (63), the non-condensable gas located in the gas passage (94) is in the gaseous state above the evaporation section (91). It is pushed into the non-condensable gas reservoir (110) by the pressure of the fluid (F). Therefore, the heat pipe function by the working fluid (F) is not hindered by the non-condensable gas, and the cooling performance of the power element (63) is improved.

  On the other hand, when it is necessary not to lower the power element (63) below a predetermined temperature, the non-condensable gas in the non-condensable gas reservoir (110) is reduced by the pressure of the working fluid (F) to the condensing part (92) or the gas passage (94 ), A large amount flows into the evaporation section (91), and the functions of the condensation section (92) and the evaporation section (91) are greatly reduced.

  Therefore, in this embodiment, since it is possible to take a large difference in heat transfer performance between when the heat pipe function for cooling the power element (63) is activated and when it is not activated, the power element (63) is kept at a predetermined temperature. While clearly switching between the cooling function for cooling under the above conditions and the temperature maintaining function for maintaining the power element (63) at a predetermined temperature (t0) (not lowering below the predetermined temperature (t0)), the cooling function is It is possible to increase.

  Furthermore, since the non-condensable gas in the non-condensable gas reservoir (110) is held at the outside air temperature, when the outside air temperature is high, the switching point between the cooling function and the temperature maintaining function, that is, the predetermined temperature (t0) is set. On the other hand, when the outside air temperature is low, the predetermined temperature (t0) can be lowered. Therefore, when the outside air temperature is high, that is, when the dew point is high, the predetermined temperature (t0) is also high. Therefore, the predetermined temperature (t0) can be set to a temperature exceeding the high dew point, and the power element (63) Condensation can be reliably prevented. On the other hand, since the dew point is low when the outside air temperature is low, it is possible to reliably prevent the power element (63) from condensing even if the predetermined temperature (t0) is set low.

  In this embodiment, the non-condensable gas reservoir (110) is connected to the heat pipe (100) through the slit (110a) for heat insulation, but the non-condensable gas reservoir (110) is further connected to an electrical component box close to the outside air temperature. Alternatively, the non-condensable gas reservoir (110) may be connected to a heat sink for exchanging heat with the outside air.

(Other embodiments)
The present invention may be configured as follows for each of the above embodiments.

  The electrical component cooled by the electrical component cooling system (70) is not limited to the power element (63). For example, you may use for cooling of a reactor etc.

  Further, the direction in which the heat pipe (90) is arranged is not limited to vertical. For example, it may be arranged obliquely.

  Furthermore, it is not essential that the upper end of the condensing part (92) is located above the upper end of the evaporating part (91), and the lower end of the condensing part (92) is located above the lower end of the evaporating part (91). It is not essential. For example, the height positions of the upper end of the condensing unit (92) and the upper end of the evaporating unit (91) are matched, and the height positions of the lower end of the condensing unit (92) and the lower end of the evaporating unit (91) are matched. Also good.

  In addition, the narrow flow paths (91a, 92a) are not essential for the evaporation section (91) and the condensation section (92). Of course, the efficiency of heat transfer of the heat pipe (90) is improved by providing the narrow flow paths (91a, 92a), but depending on the capacity required for the electrical component cooling system (70), the narrow flow paths (91a , 92a) may be determined.

  Further, a temperature sensor may be provided in the non-condensable gas reservoir (110), and the temperature of the non-condensable gas reservoir (110) may be controlled to the outside air temperature based on the temperature signal.

  The present invention is useful as a cooling system for electrical components.

DESCRIPTION OF SYMBOLS 1 Refrigerating device 10 Refrigerant circuit 60 Power converter 63 Power element (electrical equipment)
70 Electrical component cooling system 80 Refrigerant jacket (heat exchanger)
90, 100 Heat pipe (heat transfer part)
91 Evaporating section 91a Narrow flow path 92 Condensing section 92a Narrow flow path 94 Gas path 95 Liquid path 110 Non-condensable gas reservoir (non-condensable gas storage section)
110a slit

Claims (6)

In the cooling system for electrical components of the refrigeration system (1) having the refrigerant circuit (10),
A plate-shaped heat transfer section (90,100) which is arranged in an upright state and has a working fluid (F) enclosed therein;
A heat exchanger (80) supplied with refrigerant flowing through the refrigerant circuit (10),
Inside the heat transfer section (90,100)
An evaporation section (91) for cooling the electrical component by evaporation of the working fluid (F);
A condensing part (92) for condensing the working fluid (F) by the refrigerant supplied to the heat exchanger (80) is partitioned in the lateral direction,
A gas passageway (94) for connecting the upper part of the evaporator (91) and the upper part of the condenser (92) to guide the gaseous working fluid (F) of the evaporator (91) to the condenser (92). ) Is formed,
Inside the heat transfer section (90,100), non-condensable gas (N) is sealed together with the working fluid (F) ,
The electrical component cooling system according to claim 1, wherein the non-condensable gas (N) has a specific gravity such that the non-condensable gas (N) is positioned in the gas passage (94) in a state where the heat transfer section (90, 100) is erected . In the electrical component cooling system according to claim 1,
Inside the heat transfer section (90,100)
The non-condensable gas (N) is
Located in the gas passage (94), the volume of the working fluid (F) increases due to the temperature drop, and the amount of inflow to the upper part of the evaporation part (91) and the amount of inflow to the upper part of the condensing part (92) An electrical component cooling system characterized by an increase. In the cooling system for electrical components according to claim 1 or 2,
It has a non-condensable gas storage part (110) that opens to the inside of the heat transfer part (100) and adjusts the amount of the non-condensable gas (N) present in the heat transfer part (100). A cooling system for electrical components. In the electrical component cooling system according to claim 3,
The electrical component cooling system, wherein the temperature of the non-condensable gas (N) stored in the non-condensable gas storage unit (110) is adjusted to an outside air temperature. In the electrical component cooling system according to any one of claims 1 to 4,
Inside the heat transfer section (90,100)
A liquid passage (95) for connecting the lower part of the evaporator (91) and the lower part of the condenser (92) to guide the liquid working fluid (F) of the condenser (92) to the evaporator (91) A cooling system for electrical components, characterized in that is formed. In the cooling system for electrical components according to any one of claims 1 to 5,
The electrical component cooling system according to claim 1, wherein the electrical component is a power element (63) of a power converter (60).

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