JP2013228158A - Cooling device and electric vehicle including the same - Google Patents

Abstract

The cooling efficiency of a cooling device is increased by obtaining sufficient cooling performance on the upper side of a heat receiving plate.
A heat receiving unit 8 includes a heat receiving plate 12 that contacts a semiconductor switching element 6 that is a heating element and absorbs heat, and a heat receiving space 13 that covers the surface of the heat receiving plate 12 and evaporates the refrigerant 10 that has flowed in. A heat receiving cover 14 to be formed, an inlet 15 through which the refrigerant 10 condensed in the heat receiving space 13 flows, and an outlet 16 through which the refrigerant 10 is discharged from the heat receiving space 13 are provided. The circulation path 11 includes a heat dissipation path 11a and a return path 11b. The heat dissipation path 11a connects the discharge port 16 and the heat dissipating body 17 of the heat dissipating part 9, and the return path 11b connects the heat dissipating body 17 of the heat dissipating part 9 and the inflow port 15 to the heat receiving space 13 side of the inflow port 15. The inner diameter of the leading end of the provided introduction pipe 23 is larger than the inner diameter of the inflow pipe 24 provided on the side of the heat radiation path 11 a of the inflow port 15.
[Selection] Figure 4

Description

  The present invention relates to a cooling device for an electronic device equipped with a power semiconductor and an electric vehicle equipped with the same.

  Conventionally, this type of cooling device has the following configuration.

  That is, a heat receiving part, a heat radiating part connected to the heat receiving part via a heat radiating path, and a return path connecting the heat radiating part and the heat receiving part, the heat receiving part being in contact with the heating element to heat And a heat receiving cover that covers the surface of the heat receiving plate and forms a heat receiving space that evaporates the refrigerant that has flowed into the surface, and connects the return path and the heat receiving portion with an inflow pipe. A check valve is interposed in the inflow pipe, and in the heat receiving space, the heat receiving plate includes a refrigerant inflow portion at the center and a diffusion portion provided with a radial groove toward the outer periphery of the refrigerant inflow portion. It was the structure provided with the introduction pipe which extended toward the said refrigerant | coolant inflow part from the pipe | tube, and flows in the condensed refrigerant | coolant (for example, refer patent document 1).

JP 2009-88127 A

  The problem in the above conventional example is that the cooling efficiency of the cooling device decreases when the area of the heating element increases.

  That is, in the cooling device of the conventional example, a part of the refrigerant flowing into the refrigerant inflow part from the introduction pipe is brought into contact with the refrigerant inflow part and receives heat from the heat receiving plate to be boiled and vaporized. Therefore, it diffuses together with the non-boiling liquid phase refrigerant as a high-speed mixed phase flow (gas phase and liquid phase) on the diffusion part. After the initial boiling, the non-boiling liquid phase refrigerant spreads in the form of a thin film on the surface of the diffusion part. Then, by heating and vaporizing instantaneously by continuous heating from the heating element, the heat receiving plate is continuously deprived of vaporization heat and cooled.

  However, if the heating element has a large area, simply increasing the size of the heat receiving plate according to the size of the heating element does not spread the multiphase flow of the refrigerant to the outer periphery of the diffusion section, and the cooling efficiency of the cooling device decreases. there were.

  Therefore, an object of the present invention is to increase the cooling efficiency of the cooling device by spreading the multiphase flow of the refrigerant to the outer periphery of the diffusion portion even when the heating element has a large area.

In order to achieve this object, the present invention includes a heat receiving portion that includes a refrigerant inlet and outlet and receives heat from a heating element, a heat radiating portion that releases heat of the refrigerant, the heat receiving portion, and the heat receiving portion. Cooling that includes a heat dissipation path and a return path that connect the heat dissipation section, and circulates the refrigerant to the heat receiving section, the heat dissipation path, the heat dissipation section, the return path, and the heat receiving section to transfer heat. The heat receiving portion includes a heat receiving plate that contacts the heat generating element to absorb heat, and a heat receiving cover that covers the surface of the heat receiving plate and forms a heat receiving space for evaporating the refrigerant flowing into the surface. The return path and the heat receiving part are connected by an inflow pipe, and a check valve is interposed in the inflow pipe,
In the heat receiving space, the heat receiving plate has a refrigerant inflow portion at the center and a diffusion portion provided with a radial groove toward the outer periphery of the refrigerant inflow portion, and is provided from the inflow pipe or the heat receiving cover to the heat receiving plate. An introduction pipe that extends toward and into which the condensed refrigerant flows into the heat receiving space, and has an inner diameter at the heat receiving plate side tip of the introduction pipe that is larger than an inner diameter of the inflow pipe. This achieves the intended purpose.

  As described above, the present invention connects the heat receiving portion that has the refrigerant inlet and outlet and receives heat from the heating element, the heat radiating portion that releases the heat of the refrigerant, and the heat receiving portion and the heat radiating portion. A cooling device comprising a heat dissipation path and a return path, wherein the refrigerant is circulated to the heat receiving section, the heat dissipation path, the heat dissipation section, the return path, and the heat receiving section to transfer heat, The heat receiving section includes a heat receiving plate that contacts the heat generating element to absorb heat, and a heat receiving cover that covers the surface of the heat receiving plate and forms a heat receiving space that evaporates the refrigerant that has flowed into the surface, and the return path and the The heat receiving part is connected by an inflow pipe, and a check valve is interposed in the inflow pipe, and in the heat receiving space, the heat receiving plate is radially directed toward the refrigerant inflow part and the outer periphery of the refrigerant inflow part. A diffusion part provided with a groove, the inflow pipe or An introduction pipe extending from the heat-receiving cover toward the heat-receiving plate and allowing condensed refrigerant to flow into the heat-receiving space, and an inner diameter of the introduction pipe-side tip of the introduction pipe being larger than an inner diameter of the inflow pipe The cooling efficiency of the cooling device can be increased.

  That is, according to the present invention, the check valve is opened and the refrigerant supplied into the heat receiving space is partially boiled by contact with the heat receiving plate warmed by the heating element, and the rapid volume expansion at this time Therefore, it diffuses together with the non-boiling liquid phase refrigerant as a high-speed mixed phase flow (gas phase and liquid phase) on the diffusion part.

  At this time, the refrigerant supplied into the heat receiving space has a radially larger not only in the heat receiving plate side but also in the horizontal direction as the mixed phase flow because the inner diameter of the leading end of the introduction pipe on the heat receiving plate side is larger than the inner diameter of the inflow pipe. After spreading to the inner wall of the introduction pipe, it diffuses at high speed on the diffusion section, and a multiphase flow of refrigerant is supplied to the entire diffusion section, taking heat of vaporization from the entire diffusion section and cooling the heating element. it can. As a result, the cooling efficiency of the cooling device can be increased.

Schematic of the electric vehicle according to the first embodiment of the present invention. Diagram explaining basic operation of the cooling device The figure which shows the structure of the heat radiator of the cooling device (A) The figure which shows the heat receiving part of the cooling device, (b) AA sectional drawing of (a) (A) The figure which shows the heat receiving part of the cooling device, (b) BB sectional drawing of (a) (A) The figure which shows the heat-receiving part of the cooling device, (b) CC sectional drawing of (a) (A) The figure which shows the heat receiving part of the conventional cooling device, (b) DD sectional drawing of (a)

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic view when the cooling device of the present invention is mounted on an electric vehicle 1, and FIGS. 2 and 3 are configuration diagrams of the cooling device of the present invention and its heat radiating portion, respectively.

  As shown in FIG. 1, an inverter circuit 5 that supplies electric power to an electric motor 3 that drives an axle 2 of an electric vehicle 1 is disposed and connected in a front compartment 4 of the electric vehicle 1. The inverter circuit 5 includes a plurality of semiconductor switching elements 6 that supply electric power to the electric motor 3, and a cooling device 7 that cools the semiconductor switching elements 6 is also provided.

  The cooling device 7 shown in the figure includes a heat receiving portion 8 and a heat radiating portion 9 that radiates heat absorbed by the heat receiving portion 8, and a refrigerant (10 in FIG. 2) serving as a heat medium between the heat receiving portion 8 and the heat radiating portion 9. ) Is circulated, and the heat dissipating section 9 is provided with a heat dissipating body 17 that releases heat to the outside air. Further, the inverter circuit 5 is arranged in the middle of the passenger compartment front 4 close to the driver's seat side, the circulation path 11 is extended, and the radiator 17 is attached to the front grille 4a side through which outside air easily passes. It has become.

  Moreover, FIG. 2 is explanatory drawing about the cooling device 7 of Embodiment 1 by this invention. As shown in the figure, the heat receiving portion 8 includes a heat receiving plate 12 that contacts the semiconductor switching element 6 that is a heating element and absorbs heat, and a heat receiving space 13 that covers the surface of the heat receiving plate 12 and evaporates the refrigerant 10 that has flowed in. The heat receiving cover 14 to be formed, the inlet 15 into which the refrigerant 10 condensed in the heat receiving space 13 flows, the introduction pipe 23 and the inflow pipe 24 in the inlet 15, and the outlet 16 for discharging the refrigerant 10 from the heat receiving space 13 are provided. Is.

  The heat receiving plate 12 includes a refrigerant inflow portion 21 in the center and a diffusion portion 22 provided with a radial groove 22a around the heat inflow portion 21 as will be described later with reference to FIG.

  The circulation path 11 includes a heat dissipation path 11a and a return path 11b. The heat dissipation path 11a connects the discharge port 16 and the heat dissipating body 17 of the heat dissipating unit 9, and the return path 11b receives the heat dissipating body 17 and the heat receiving unit 17 of the heat dissipating unit 9. It is the structure which connected the part 8. FIG.

  And heat is radiated by blowing outside air from the blower 17a to the interface of the heat radiating body 17. In addition, the heat radiation from the interface of the heat radiating body 17 can also be utilized for heating in one electric vehicle.

  Further, as shown in FIG. 3, the radiator 17 is a block body in which a plurality of fins 19 formed by thinly forming an aluminum plate in a strip shape are stacked at a predetermined interval, and an inlet and an outlet of the radiator 17 are provided. A plurality of pipe lines 18 to be connected penetrate the fins 19. Here, at the entrance of the radiator 17, a plurality of pipe lines 18 connected to the heat dissipation path 11 a divides the flow path into a plurality of channels, and at the outlet of the radiator 17, the return path 11 b is connected to the plurality of pipe lines 18. It is the structure which joins a some flow path. Thus, the plurality of pipe lines 18 connect the heat radiation path 11a and the return path 11b, and the heat of the refrigerant 10 is transmitted to the entire fin 19 so that the heat radiation efficiency of the heat radiation unit 9 is increased.

  The above is the description of the main configuration of the present invention.

  Here, the basic operation of the cooling device and the check valve operation condition will be described with reference to FIG.

  First, the basic operation of the cooling device 7 will be described. The heat generated by the semiconductor switching element 6 is transmitted from the heat receiving plate 12 to the liquefied refrigerant 10 in the heat receiving space 13 and instantly evaporates.

  Next, the refrigerant 10 after boiling (the gas phase and a part of the non-boiling refrigerant) generates a refrigerant driving force due to an internal pressure difference between the heat receiving space 13 and the cooled heat radiating body 17, and the heat radiation path 11a from the discharge port 16 is generated. And then flows into the heat dissipating body 17. At this time, the circulation direction of the refrigerant is fixed in the direction of the heat radiation path 11 a by the check valve 20.

  That is, the pressure in the heat receiving space 13 increases when the refrigerant 10 boils, but the refrigerant 10 prevents the refrigerant 10 from flowing back due to the action of the check valve 20 and returning to the inflow pipe 24 side. Due to the pressure difference between the heat receiving space 13 and the cooled heat radiating body 17 due to the refrigerant 10, the refrigerant 10 is discharged as a mixed phase flow of both the vapor phase (vapor) and the non-boiling liquid phase without using external power. It can be reliably transported from the outlet 16 to the heat dissipating body 17 through the heat dissipating path 11a.

  The vapor phase component of the refrigerant 10 contacts the inner wall surface of the radiator 17 cooled by the outside air and condenses, so that the heat of condensation is transmitted to the radiator 17, and from the inner wall surface of the radiator 17 to the outer wall of the fin 19. It is transmitted to the surface, and finally it is dissipated by exchanging heat with the outside air.

  Further, the refrigerant 10 liquefied by the condensation flows through the return path 11 b and stops on the check valve 20 of the inlet 15 in the inflow pipe 24, and the moment when the valve is opened under a predetermined operating condition of the check valve 20. In addition, the refrigerant 10 flows into the heat receiving space 13 again. Usually, stable cooling is possible by repeating this series of cycles.

  Next, the operating conditions of the predetermined check valve 20 will be described. The check valve 20 when the boiling operation by the normal heating is continued is determined by the upstream pressure Pu of the check valve 20 (pressure in the return path 11b + retained refrigerant head pressure in the inflow pipe 24) and the heat receiving space 13. The applied downstream pressure Pb of the check valve 20 is almost balanced and is closed.

  Normally, when heating is continued as it is and vaporization of the refrigerant further proceeds in the heat receiving space 13, the refrigerant supply to the upstream side of the check valve 20 is continued even if the temperature and the saturated vapor pressure are constant. The water head pressure of the refrigerant will gradually increase. Therefore, at a certain moment, a state where the upstream pressure Pu of the check valve 20> the downstream pressure Pb of the check valve 20 occurs, and the check valve 20 opens.

  Then, the refrigerant amount corresponding to the increased head pressure of the pressure difference flows into the heat receiving space 13 through the introduction pipe 23, and is closed again at the timing when the pressures on both sides of the check valve 20 are balanced. Become. A refrigerant supply cycle is realized by the operation of the series of check valves 20. The actual opening / closing timing of the check valve 20 occurs at a certain time interval, but it is not necessarily the same because it varies depending on the specifications of the device (the amount of heat generated, the amount of refrigerant contained in the device, and the rigidity of the valve). .

  Next, with reference to FIG. 4, the basic mechanism of heat reception in the heat receiving space 13 and the operation of the predetermined check valve 20 will be additionally described.

  First, as a heat receiving mechanism in the heat receiving space 13, the following boiling phenomenon has occurred. As shown in FIG. 4, the refrigerant that has flowed into the heat receiving space 13 when the check valve 20 is opened is guided to the refrigerant inflow portion 21 of the heat receiving plate 12 by the introduction pipe 23, and part of the refrigerant receives heat from the heat receiving plate 12. Then, the gas is boiled and vaporized, and diffused radially on the diffusion portion 22 as a high-speed multiphase flow (gas phase and liquid phase) from the gap between the opening of the introduction pipe 23 and the diffusion portion 22 to the outer peripheral portion by rapid volume expansion. A region indicated by hatching in FIG. 4B represents a multiphase flow diffusion region indicated by an arrow in FIG.

  The diffusion portion 22 has a structure in which the groove 22a, which is a radial flow path, expands from the central portion to the outer peripheral portion, and has a wide boiling surface area. After the initial boiling, the non-boiling liquid phase refrigerant 10 spreads in the form of a thin film on the surface of the diffusion portion 22. Then, the continuous heating from the semiconductor switching element 6 heats and vaporizes instantaneously in this radial flow path, so that it is possible to achieve highly efficient heat receiving performance while maintaining an extremely high transfer coefficient.

  In the present embodiment, for example, when water is used as the refrigerant 10, the pressure in the heat receiving space 13 is set to be lower than the atmospheric pressure (when the outside air temperature is 20 ° C., the saturated vapor pressure of water is −97 KPa). Therefore, it is possible to boil at a temperature lower than that of water at atmospheric pressure, so that high cooling performance is possible.

  Thereby, the heat of the semiconductor switching element 6 can be efficiently taken and cooled. That is, the heat of the semiconductor switching element 6 is taken away by the latent heat of evaporation of water, and the refrigerant 10 spreading in a thin film shape on the heat receiving plate 12 as described above is heated and vaporized instantaneously. The heat transfer coefficient is much higher than that obtained by simply warming and boiling the accumulated water, and the amount of heat lost can be greatly increased.

  By enabling continuous boiling in the heat receiving space 13 as described above, a regular heat receiving and radiating cycle can be maintained, and a high-performance cooling device can be realized.

  Since the semiconductor switching element 6 can be stably cooled in this way, the flattening phenomenon (refrigerant is reduced in particular) can be fixed in one direction by the check valve, particularly in the gas-phase and liquid-phase refrigerant circulation directions. The reverse flow can prevent problems such as a state in which the heat transport direction is not determined and the cooling efficiency is significantly reduced, and the operational stability of the cooling device can be improved.

  In addition, as described above, the refrigerant driving force in the cooling device according to the present invention is generated by the pressure difference between the pressure in the heat receiving space 13 due to boiling and the radiator 17 that is in a low temperature and low pressure state due to the outside air. The point that the special refrigerant driving device is not required at all makes it possible to realize a very effective cooling device from the viewpoint of energy saving.

  Since the refrigerant 10 is driven by the pressure balance in the cooling device 7 as described above, the heat receiving portion 8 and the heat radiating portion 9 can be arranged separately from each other.

  In other words, the inverter circuit 5 that is sensitive to dust and water droplets and the heat dissipating part 9 that is to be cooled efficiently by applying outside air can be installed separately such as the front grill 4a of the electric vehicle 1 and the front 4 of the passenger compartment. Therefore, it is advantageous in terms of reliability, and can greatly contribute to ensuring more stable running performance of the electric vehicle 1.

  Now, the basic portion of the present invention has been described as above, but the introduction pipe 23 when the area of the heating element, which is the most important feature in the present embodiment, is increased as shown in FIG. A description will be added with reference to FIG. The area indicated by hatching in each figure (b) represents the diffusion region of the multiphase flow indicated by the arrow shown in each figure (a).

  FIG. 7A shows a conventional case where the area of the heating element shown in FIG. 4 is increased, and the heat receiving plate is enlarged according to the size of the heating element, and FIG. The flow diffusion region does not extend to the entire diffusion portion 22.

  On the other hand, FIG. 5A of the present embodiment has a configuration in which the inner diameter of the introduction pipe 23 a is about three times the inner diameter of the inflow pipe 24. The refrigerant supplied from the check valve 20 into the heat receiving space 13 by the introduction pipe 23a is compared with the case where the inner diameter of the introduction pipe 23a and the inner diameter of the inflow pipe 24 shown in FIG. As shown in FIG. 7B, the diffusion region is wider in FIG. 5, and the mixed phase flow of the refrigerant is supplied to the entire surface of the diffusion unit 22, and the cooling efficiency is increased by boiling and vaporization in the entire diffusion unit 22. Is possible.

  That is, with the configuration in which the inner diameter of the introduction pipe 23a is made larger than the inner diameter of the inflow pipe 24, the position X at which the refrigerant diffusion speed is highest (= the position where the opening area is minimized) is further away from the refrigerant inflow section 21; A multiphase flow of refrigerant is supplied to the entire surface of the diffusion unit 22.

  Further, the position of the check valve 20 in the inflow pipe 24 is preferably close to the tip of the heat receiving portion 8 side. As shown in FIG. 5 (a), when the check valve 20 is provided at the end of the heat receiving portion 8, the vaporized refrigerant supplied from the check valve 20 into the heat receiving space 13 is horizontal along the heat receiving plate 12. Most of the diffusion velocity vector becomes a horizontal component, and the horizontal component of the diffusion velocity vector remains after moving from the introduction tube 23a into the groove 22a of the diffusion portion 22, and is easily spread in the horizontal direction.

  Further, the length of the introduction pipe 23a is determined from the distance between the lower end surface of the introduction pipe 23a and the upper surface of the heat receiving plate 12, and as shown in FIG. By opening the gap, the multiphase flow of the refrigerant spreads not only in the groove 22a of the diffusion portion 22 but also in the entire diffusion portion 22, and the entire diffusion portion 22 can be used as a heat transfer surface. However, if the gap becomes large, the diffusion speed of the refrigerant in the multiphase flow passing through the opening including this gap becomes slow, and the refrigerant may not spread over the entire diffusion region indicated by hatching in FIG. Is determined so that the diffusion speed of the opening is a speed at which the refrigerant spreads over the entire diffusion region.

  Further, although the diameter of the introduction pipe 23a is about ½ of the length of the groove 22a, it greatly affects the diffusion speed of the refrigerant 10 and therefore needs to be determined according to the area of the heating element. It is desirable to select the diameter of the introduction pipe 23a that provides a diffusion rate that can spread the refrigerant 10 uniformly over the area 22.

  Further, by forming the introduction pipe 23a integrally with the heat receiving cover 14, the manufacture becomes easy, and the accuracy of the gap described above can be improved.

  Thus, the configuration of FIG. 5 can achieve highly efficient heat receiving performance with an extremely high transfer coefficient that is almost the same as the standard case even when the area of the heating element is increased. It becomes possible.

(Embodiment 2)
The same components as those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The introduction pipe 23b in FIG. 6 is different in shape from the introduction pipe 23a in FIG. 5, and its inner diameter gradually increases from the heat receiving cover 14 side to the heat receiving plate 12 side.

  With this configuration, the refrigerant that is supplied from the check valve 20 into the heat receiving space 13 and partially vaporized is likely to spread substantially obliquely downward along the gentle slope of the inner wall of the introduction pipe 23b, and the diffusion velocity vector also has a higher vertical component than the vertical component. Since the horizontal component is larger, the horizontal component of the diffusion velocity vector remains after the movement from the lowermost surface of the introduction tube 23b into the groove 22a of the diffusion portion 22 as in FIG. 5, and it tends to spread in the horizontal direction.

  The diameter and length of the introduction pipe 23b and the integral formation with the heat receiving cover 14 are the same as in FIG. 5, and the merit compared to FIG. 5 is that the collision with the introduction pipe 23b of the multiphase flow is reduced, that is, in FIG. Since there is no such an orthogonal collision and there is little pressure loss, it passes through the minimum opening on the lowermost surface of the introduction pipe 23b, so the diffusion speed passing through the opening is faster than in FIG. The refrigerant can be spread over the entire diffusion zone.

  As described above, since the inner diameters of the leading ends of the introduction pipes 23a and 23b on the side of the heat receiving plate 12 are made larger than the inner diameter of the inflow pipe 24, the refrigerant 10 supplied into the heat receiving space is not limited to the heat receiving plate 12 side. It spreads radially in the direction, spreads to the inner wall of the introduction tube, and then diffuses on the diffusion portion 22 at high speed.

  Therefore, the mixed phase flow of the refrigerant 10 is supplied to the entire diffusion unit 22, and the heat of vaporization can be taken from the entire diffusion unit 22 to be cooled. That is, by setting the position X at which the refrigerant diffusion speed is maximum (= the position where the opening area is minimum) as a position farther from the refrigerant inflow part, a sufficient mixed phase flow of the refrigerant 10 can be supplied to the entire diffusion part 22. Thus, it is possible to provide a cooling device capable of improving the cooling efficiency even for a heating element having a large area.

  According to the present invention, it is possible to obtain a cooling device that maintains a regular heat receiving and radiating cycle regardless of the size of the heating element and has a stable cooling performance. And is useful for cooling high-speed arithmetic processing devices.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 2 Axle 3 Electric motor 4 Car front 4a Front grille 5 Inverter circuit 6 Semiconductor switching element 7 Cooling device 8 Heat receiving part 9 Heat radiating part 10 Refrigerant 11 Circulating path 11a Heat radiating path 11b Return path 12 Heat receiving plate 13 Heat receiving space 15 Inlet 16 discharge port 17 heat radiating body 17a air blower 18 pipe 19 fin 20 check valve 21 refrigerant inflow part 22 diffusion part 22a groove 23, 23a, 23b introduction pipe 24 inflow pipe

Claims (4)

A heat receiving portion that receives heat from the heating element;
A heat dissipating part that releases the heat of the refrigerant;
Consists of a heat dissipation path and a return path connecting the heat receiving section and the heat dissipation section,
A cooling device that circulates the refrigerant to the heat receiving unit, the heat dissipation path, the heat dissipation unit, the return path, and the heat receiving unit to transfer heat,
The heat receiving part is in contact with a heating element and absorbs heat; and
A heat receiving cover that covers the surface of the heat receiving plate and forms a heat receiving space for evaporating the refrigerant flowing into the surface;
The return path and the heat receiving part are connected by an inflow pipe, and a check valve is interposed in the inflow pipe,
In the heat receiving space, the heat receiving plate has a refrigerant inflow portion in the center and a diffusion portion provided with a radial groove toward the outer periphery of the refrigerant inflow portion,
An introduction pipe extending from the inflow pipe or the heat receiving cover toward the heat receiving plate and allowing the condensed refrigerant to flow into the heat receiving space;
The cooling device according to claim 1, wherein an inner diameter of a tip of the introduction pipe on the heat receiving plate side is larger than an inner diameter of the inflow pipe. 2. The cooling device according to claim 1, wherein an inner diameter of the introduction pipe gradually increases from the heat receiving cover side toward the heat receiving plate side. The cooling device according to claim 1 or 2, wherein a check valve is arranged at a heat receiving plate side tip of the inflow pipe. An electric vehicle comprising the cooling device according to claim 1.

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