JP2012186422A - Cooling device for electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for electric equipment capable of simplifying a structure while realizing excellent cooling efficiency.SOLUTION: A cooling device 20 for a power control unit has: a PCU case 24 where coolant is encapsulated; a passage forming board 30 which forms a circulation passage 40 to circulate the coolant; heater elements 36; and a radiator section 26 on the PCU case 24. The passage forming board 30 has a plurality of rectifying partition wall sections 31 which are arranged at a vertical interval each other. The circulation passage 40 has a straight section 41A arranged in an upper section and another straight section 41B arranged in a lower section. The rectifying partition wall section 31p has opening sections 32 which communicate between the straight section 41A and the other straight section 41B. The heater elements 36 are arranged so that, in the straight section 41B, a heat value in a region 110 opposite to the opening section 32 is larger than the heat values in the regions 120 which are opposite to the rectifying partition wall section 31p and have an equal area to the region 110.

Description

  The present invention generally relates to a cooling device for electrical equipment, and more particularly to a cooling device for electrical equipment using a refrigerant having excellent electrical insulation and thermal conductivity.

  With respect to a conventional cooling device for electrical equipment, for example, International Publication No. 2000/16397 discloses an electronic equipment intended to suppress cooling water pressure loss while efficiently cooling a semiconductor package having a large calorific value. Is disclosed (Patent Document 1). In the electronic device disclosed in Patent Document 1, cooled water is circulated using a pump in a housing on which a semiconductor module is mounted. During the cooling of the semiconductor module, water flows through a water channel formed in a meandering shape.

International Publication No. 2000/16397

  An apparatus for cooling a heating element such as a semiconductor module while circulating a coolant such as cooling water is used. However, in the electronic device disclosed in Patent Document 1, since a pump for circulating the cooling water is provided, the structure of the cooling device cannot be simplified sufficiently. On the other hand, in order to simplify the structure of the cooling device, there is an idea that the refrigerant is naturally circulated using thermal convection. However, in this case, the flow rate of the refrigerant depends on the amount of heat generated by the heating element. For this reason, there is a concern that the flow velocity is reduced at a position where the pressure loss of the refrigerant passage is large, and the cooling efficiency of the heating element is lowered.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a cooling device for an electric device that can achieve a simple structure while realizing excellent cooling efficiency.

  A cooling device for an electrical device according to the present invention includes a sealed casing in which an electrically insulating refrigerant is sealed, a passage forming member that forms a circulation path for circulating the refrigerant in the sealed casing, and a circulation path And a heat dissipating part disposed on the upper side in the vertical direction from the heat generating element and provided in the sealed casing. The passage forming member has a plurality of partition walls that are spaced apart from each other in the vertical direction. The circulation passage has an upper passage and a lower passage. The lower passage is separated from the upper passage by the partition wall portion, and is disposed on the lower side in the vertical direction than the upper passage. An opening is formed in the partition wall. The opening communicates between the upper passage and the lower passage and guides the refrigerant from the lower passage to the upper passage. The heat generating element is provided in the lower passage such that the heat generation amount in the first region facing the opening is larger than the heat generation amount in the second region facing the partition wall and having the same area as the first region.

  According to the cooling device for an electric device configured as described above, the refrigerant circulates from the lower side to the upper side in the sealed casing while passing between adjacent partition walls due to the temperature rise due to heat received from the heating element. Flow through the passage. The refrigerant whose temperature has risen is cooled by exchanging heat with the heat dissipating part disposed above the heat generating element in the vertical direction, and returned again to the lower side in the sealed casing. In the present invention, the structure of the cooling device can be simplified by utilizing such heat convection of the refrigerant. Further, the heat generating element is provided in the lower passage such that the amount of heat generated in the first region facing the opening is larger than the amount of heat generated in the second region facing the partition wall and having the same area as the first region. . Thus, when the refrigerant travels from the lower passage to the upper passage through the opening, the temperature of the refrigerant flowing through the lower passage is increased more greatly in the first region directly below the opening, and can be smoothly guided to the upper passage. it can. Thereby, the flow rate of a refrigerant | coolant increases and it can improve the cooling efficiency of a heat generating element.

  Preferably, the plurality of heating elements are arranged in the lower passage such that the arrangement density is larger in the first region than in the second region. According to the cooling device for an electrical device configured as described above, the heat generation amount in the first region can be set larger than the heat generation amount in the second region due to the density of the plurality of heating elements arranged in the lower passage.

  Preferably, the plurality of partition walls include a first partition wall and a second partition wall arranged adjacent to each other. The first partition wall and the second partition wall are arranged such that the area of the circulation passage formed between the first partition wall and the second partition wall is larger on the downstream side than on the upstream side of the refrigerant flow. . According to the cooling device for an electric device configured as described above, the pressure of the refrigerant flowing through the circulation passage is high on the upstream side of the refrigerant flow and low on the downstream side. Thereby, the flow rate of a refrigerant | coolant increases and the cooling efficiency of a heat generating element can further be improved.

  Preferably, the plurality of partition walls are arranged such that the circulation passage extends while meandering from the lower side to the upper side in the vertical direction. According to the cooling device for an electric device configured as described above, more heat generating elements can be arranged on the circulation passage through which the refrigerant circulates while reducing the size of the refrigerant device.

  Preferably, the plurality of partition walls include a third partition wall disposed on the uppermost side in the vertical direction and a fourth partition wall disposed on the lowermost side in the vertical direction. The passage forming member further includes a return passage partition that extends between the third partition and the fourth partition and returns the coolant cooled by the heat radiating portion to the upstream side of the coolant flow. The return path partition wall portion has a smaller thermal conductivity than the third partition wall portion and the fourth partition wall portion.

  According to the cooling device for an electric device configured as described above, the return passage partition wall is provided between the fourth partition wall on the upstream side of the refrigerant flow and the third partition wall on the downstream side of the coolant flow. Suppresses the transfer of heat. Thereby, the refrigerant | coolant cooled by the thermal radiation part can be returned more smoothly from the downstream of a refrigerant | coolant flow to the upstream. As a result, the flow rate of the refrigerant is increased, and the cooling efficiency of the heating element can be further improved.

  Preferably, the heat generating element is mounted on the partition wall. According to the cooling structure of the electrical device configured as described above, the structure of the cooling device can be simplified.

  Preferably, the cooling device for an electric device further includes an element fixing portion that is interposed between the partition wall and the heating element and fixes the heating element to the partition wall. The element fixing portion is formed of a material having electrical insulation. According to the cooling device for an electric device configured as described above, the element fixing portion secures electrical insulation with respect to the heating element. Thereby, since the freedom degree of the material which forms a partition part increases, the heat exchange between the partition part which forms a circulation path, and the refrigerant | coolant which flows through a circulation path can be promoted.

  Preferably, the electrical device cooling apparatus further includes an element mounting base provided in the circulation passage at a position spaced from the partition wall and on which the heating element is mounted. According to the cooling device for an electric device configured as described above, the cooling efficiency of the heat generating element can be further improved by disposing the element mounting base at a position where the flow rate of the refrigerant is increased in the circulation passage.

  Preferably, the refrigerant is pressurized to a saturation vapor pressure or higher and enclosed in a sealed casing. According to the cooling device for an electric device configured as described above, bubbles are not generated in the refrigerant that has received heat from the heating element. This eliminates the concern that a discharge occurs between the heating elements due to the generation of bubbles. As a result, the distance between the heating elements can be set smaller, and the cooling device can be downsized.

  As described above, according to the present invention, it is possible to provide a cooling device for an electric device that can achieve a simple structure while realizing excellent cooling efficiency.

It is a side view which shows a hybrid vehicle. It is an electric circuit diagram for demonstrating the electric power control unit mounted in the hybrid vehicle in FIG. It is sectional drawing which shows the cooling device of the electric power control unit in FIG. It is sectional drawing which shows the refrigerant | coolant flow formed in the PCU case in FIG. It is sectional drawing which shows the cooling device of the power control unit in Embodiment 2 of this invention. It is sectional drawing which shows the cooling device of the power control unit in Embodiment 3 of this invention. It is sectional drawing which shows the cooling device of the power control unit in Embodiment 4 of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a side view showing a hybrid vehicle. In the present embodiment, a case will be described in which the present invention is applied to an apparatus for cooling a power control unit (PCU) mounted on a hybrid vehicle 10.

  Referring to FIG. 1, hybrid vehicle 10 uses an internal combustion engine such as a gasoline engine or a diesel engine and a motor supplied with power from a chargeable / dischargeable secondary battery (battery) as a power source.

  An engine room 15 is formed in the hybrid vehicle 10. The engine room 15 is disposed in front of the vehicle. The engine room 15 is provided so that traveling wind can be taken in through a grid-like front grill or the like when the hybrid vehicle 10 is traveling. The power control unit cooling device 20 in the present embodiment is disposed in the engine room 15.

  FIG. 2 is an electric circuit diagram for explaining a power control unit mounted on the hybrid vehicle in FIG.

  Referring to FIG. 2, power control unit 60 includes a motor generator 52 and a motor generator 54 serving as rotating electrical machines that operate with high voltage AC power by using DC power of high voltage power storage device 50 and low voltage power storage device 56. The LV (low-level voltage) device 58 that operates by voltage has a function of converting to a state suitable for each operation, such as voltage and alternating current. Conversely, the regenerative electric power from the motor generator 52 and the motor generator 54 is also converted into a voltage and direct current suitable for the high voltage power storage device 50 and charged to the high voltage power storage device 50.

  The high voltage power storage device 50 connected to the power control unit 60 is a chargeable / dischargeable high voltage secondary battery (battery). As such a high voltage power storage device 50, for example, a lithium ion battery, a nickel hydrogen battery, a capacitor, or the like having a terminal voltage of 200 to 300V is used. The low voltage power storage device 56 connected to the power control unit 60 is a chargeable / dischargeable low voltage secondary battery. As such a low voltage power storage device 56, for example, a lead storage battery having a nominal voltage of 12 to 14 V is used.

  The motor generator 52 and the motor generator 54 connected to the power control unit 60 are three-phase synchronous rotating electric machines that function as motors when electric power is supplied and function as generators during braking.

  The motor generator 52 indicated as MG1 in FIG. 2 is connected to the engine and mainly functions as a generator. The motor generator 52 generates AC power by the output of the engine. The generated AC voltage is converted into DC power by an MG1 inverter 68, which will be described later, and charges the high-voltage power storage device 50.

  The motor generator 54 indicated as MG2 in FIG. 2 mainly functions as a motor for assisting engine output and increasing driving force. AC power is obtained by converting DC power of the high-voltage power storage device 50 by an inverter 70 for MG2, which will be described later, and the motor generator 54 is operated by the AC power. The motor generator 54 also has a function as a generator that collects the regenerative energy during braking of the hybrid vehicle 10 and generates AC power. The generated AC voltage is converted into DC power by the inverter 70 and charges the high-voltage power storage device 50.

  The LV device 58 connected in parallel to the low voltage power storage device 56 with respect to the power control unit 60 is a device that operates according to the voltage of the low voltage power storage device 56, and is a device such as an audio device, a lighting device, a small motor, and the like. And electronic devices such as microprocessors and electric circuits.

  The power control unit 60 includes smoothing capacitors 62, 66 and 74, an HV (high-level voltage) converter 64 which is a high-voltage side voltage converter, an LV (low-level voltage) converter 72, a motor generator. 52 includes an MG1 inverter 68 connected to 52 and an MG2 inverter 70 connected to the motor generator 54.

  The smoothing capacitor 62 provided between the high voltage power storage device 50 and the HV converter 64 is a capacitive element used to suppress fluctuations in voltage and current on the high voltage power storage device 50 side. A smoothing capacitor 66 provided between the HV converter 64 and the inverters 68 and 70 is a capacitive element used to suppress fluctuations in voltage and current on the inverters 68 and 70 side. The smoothing capacitor 74 provided between the LV converter 72 and the low voltage power storage device 56 is a capacitive element used to suppress fluctuations in voltage and current on the low voltage power storage device 56 side.

  HV converter 64 is provided between high voltage power storage device 50 and inverter 68 and inverter 70, and has a function of performing voltage conversion between the voltage between terminals of high voltage power storage device 50 and the voltage on the inverters 68 and 70 side. Is a converter circuit. As such an HV converter 64, a converter including a reactor and a switching element is used.

  The LV converter 72 is provided between the high voltage power storage device 50 and the low voltage power storage device 56 and has a function of performing voltage conversion between the voltage between the terminals of the high voltage power storage device 50 and the voltage of the low voltage power storage device 56. It is the converter circuit which has. As such an LV converter 72, a converter including a reactor and a switching element is used similarly to the HV converter 64.

  Inverters 68 and 70 convert high voltage DC power into AC three-phase drive power and supply it to motor generators 52 and 54, and convert AC three-phase drive power from motor generators 52 and 54 into high voltage DC power. A circuit having a function of Such inverters 68 and 70 are constituted by a circuit including a switching element (IGBT: Insulated Gate Bipolar Transistor) and a diode.

  As described above, the power control unit 60 includes a converter, an inverter, a capacitor, and the like, and these are configured by various elements such as a switching element, a diode, a reactor, and a capacitive element.

  Then, the structure of the cooling device 20 of the power control unit in the present embodiment will be described.

  3 is a cross-sectional view showing a cooling device of the power control unit in FIG. Referring to FIG. 3, cooling device 20 for the power control unit in the present embodiment has PCU case 24, heating element 36, and radiator section 26.

  The PCU case 24 is provided so as to form a sealed space therein. The PCU case 24 is formed, for example, by combining a lower container and an upper container and sealing between the two. The PCU case 24 has a casing shape having a top portion 24t and a bottom portion 24b facing each other. The PCU case 24 is made of a metal such as aluminum.

  An electrically insulating refrigerant is sealed in the PCU case 24. In the present embodiment, a liquid excellent in electrical insulation and thermal conductivity, such as a fluorine-based inert liquid, is enclosed in the PCU case 24. The refrigerant is provided so as to fill the PCU case 24. The refrigerant is pressurized to the saturated vapor pressure or higher and sealed in the PCU case 24.

  The radiator section 26 has a fin shape, and is integrally formed with the PCU case 24 in the present embodiment. The radiator portion 26 is formed on the top portion 24 t of the PCU case 24. The cooling device 20 is arranged so that the traveling wind taken into the engine room 15 in FIG. 1 is directed to the radiator unit 26.

  The heating element 36 is the various elements that constitute the power control unit 60, and generates heat when the power control unit 60 is operated. The heat generating element 36 is immersed in a refrigerant sealed in the PCU case 24.

  The power control unit cooling device 20 according to the present embodiment further includes a passage forming plate 30. The passage forming plate 30 is configured by combining a plurality of plate materials. The passage forming plate 30 is disposed in the PCU case 24. The passage forming plate 30 forms a circulation passage 40 in the PCU case 24 for circulating the refrigerant.

  The circulation passage 40 includes a meandering passage 41 and a return passage 46. The meandering passage 41 is formed in the PCU case 24 so as to extend while meandering from the lower side to the upper side in the vertical direction. The return passage 46 extends along the vertical direction so as to connect the lower portion and the upper portion of the meandering passage 41.

  In the present embodiment, the circulation passage 40 is formed so that there is only one circulation path, that is, there is no portion that branches in the middle when the circulation passage 40 goes around. With such a configuration, the heat convection refrigerant can be circulated through the circulation passage 40 as intended. As a result, the plurality of heating elements 36 arranged in the circulation passage 40 can be cooled without variation.

  The passage forming plate 30 includes a rectifying partition wall portion 31p, a rectifying partition wall portion 31q, a rectifying partition wall portion 31r (hereinafter referred to as a rectifying partition wall portion 31 unless otherwise specified), and a return passage partition wall portion 33. ing.

  The rectifying partition wall 31 has a flat plate shape. The rectifying partition wall 31 is formed of a material having excellent thermal conductivity. The rectifying partition wall 31 is made of a metal such as aluminum or copper, for example. The rectifying partition wall 31 is made of a conductive material.

  The return passage partition wall 33 has a flat plate shape. The return passage partition wall 33 is preferably formed of a material having lower thermal conductivity than the rectification partition wall 31p and the rectification partition wall 31r. The return passage partition wall 33 may be formed of the same material as the rectifying partition wall 31.

  The rectifying partition wall portion 31p, the rectifying partition wall portion 31q, and the rectifying partition wall portion 31r are positioned at intervals in the vertical direction. The rectifying partition wall portion 31p, the rectifying partition wall portion 31q, and the rectifying partition wall portion 31r are arranged in layers in the vertical direction. Among the plurality of rectifying partition walls 31, the rectifying partition wall portion 31p is disposed on the uppermost side in the vertical direction, the rectifying partition wall portion 31r is disposed on the lowermost side in the vertical direction, and the rectifying partition wall portion 31q is In the vertical direction, it is arranged between the rectifying partition wall 31p and the rectifying partition wall 31r. The rectifying partition wall 31p is disposed to face the top 24t of the PCU case 24. The rectifying partition wall 31r is arranged to face the bottom 24b of the PCU case 24.

  The rectifying partition wall 31 has an upper surface 31m facing the upper side in the vertical direction and a lower surface 31n disposed on the back side of the upper surface 31m and facing the lower side in the vertical direction. The rectifying partition walls 31 adjacent to each other are arranged such that the upper surface 31m and the lower surface 31n face each other.

  The return passage partition wall 33 extends between the rectification partition wall 31p and the rectification partition wall 31r. The return passage partition wall 33 extends in the vertical direction. The rectifying partition wall portion 31p, the return passage partition wall portion 33, and the rectifying partition wall portion 31r include a partition wall support spacer 39 that connects the return passage partition wall portion 33 and the PCU case 24, and the rectifying partition wall portion 31p and the PCU case 24. Are supported in the PCU case 24 by partition wall support spacers 38 connecting the two. On the other hand, the rectifying partition wall 31q is directly connected to and supported by the PCU case 24.

  The meandering passage 41 includes a straight portion 41A, a straight portion 41B, a straight portion 41C and a straight portion 41D, and a plurality of bent portions 41E.

  A straight portion 41A is formed between the top 24t of the PCU case 24 and the rectifying partition wall portion 31p, and a straight portion 41B is formed between the rectifying partition wall portion 31p and the rectifying partition wall portion 31q. A straight portion 41C is formed between the portion 31q and the rectifying partition wall portion 31r, and a straight portion 41D is formed between the rectifying partition wall portion 31r and the bottom portion 24b of the PCU case 24. That is, the straight portion 41A and the straight portion 41B are partitioned by the rectifying partition wall portion 31p, and the straight portion 41B and the straight portion 41C are partitioned by the rectifying partition wall portion 31q, and the straight portion 41C and the straight portion 41D are separated. Is partitioned by a rectifying partition wall 31r. The plurality of bent portions 41E extend in the vertical direction so as to connect between the straight portions 41A and 41B, between the straight portions 41B and 41C, and between the straight portions 41C and 41D. Is formed.

  An opening 32 is formed in the rectifying partition wall 31. The opening 32 is disposed in each of the plurality of bent portions 41E. The opening 32 allows the upper and lower straight portions 41 </ b> A to 41 </ b> D defined by the partition wall 31 for rectification formed with the opening 32 to communicate with each other. More specifically, the opening 32 formed in the rectifying partition wall 31p allows communication between the straight portion 41A and the straight portion 41B. The opening 32 formed in the rectifying partition wall 31q allows communication between the straight portion 41B and the straight portion 41C. The opening 32 formed in the rectifying partition wall 31r allows communication between the straight portion 41C and the straight portion 41D.

  The heating element 36 is provided in the circulation passage 40. The heating element 36 is provided in the meandering passage 41. The heat generating elements 36 are provided in the straight portion 41A, the straight portion 41B, and the straight portion 41C. In the present embodiment, the heating element 36 is mounted on the rectifying partition wall 31. The heat generating elements 36 are spaced apart from each other along the flow direction of the refrigerant in the circulation passage 40.

  The heating element 36 is mounted on the upper surface 31m of the upper surface 31m and the lower surface 31n of the rectifying partition wall 31. The radiator section 26 is disposed above the heat generating element 36 in the vertical direction. The radiator unit 26 is disposed on the upper side in the vertical direction with respect to all of the plurality of heating elements 36 provided.

  A mode in which the heat generating element 36 is provided in the linear portion 41B will be described in detail. A region 110 and a region 120 are defined in the straight line portion 41B. The region 110 is defined at a position facing the opening 32 formed in the rectifying partition wall 31p.

  The region 120 has the same area as the region 110 and is defined at an arbitrary position facing the rectifying partition wall 31p. In FIG. 3, a region 120D is defined at a position facing the rectifying partition wall portion 31p and including the four heat generating elements 36, and at a position facing the rectifying partition wall portion 31p, two heating elements are formed. A region 120U is defined at a position including 36. The region 120D has the same area as the region 110, and the region 120U has the same area as the region 110. The region 120U, the region 120D, and the region 110 are arranged in the order given from the upstream side to the downstream side of the refrigerant flow in the linear portion 41B.

  In this case, the heat generating element 36 is provided in the linear portion 41B so that the heat generation amount of the heat generating element 36 in the region 110 is larger than the heat generation amount of the heat generating element 36 in the region 120. The amount of heat generated by the heat generating element 36 in the region 110 is larger than the amount of heat generated by the heat generating element 36 in the region 120D, and larger than the amount of heat generated by the heat generating element 36 in the region 120U. In FIG. 3, the region 120D and the region 120U are defined so as to intentionally include a large number of the heating elements 36. However, no matter how the region 120 is set in the linear portion 41B, the heating elements 36 in the region 110 are not limited. The heat generation amount is larger than the heat generation amount of the heat generating element 36 in the region 120.

  In the present embodiment, the plurality of heating elements 36 are arranged so that the arrangement density thereof is larger in the region 110 than in the region 120. In the example shown in FIG. 3, five heat generating elements 36 are arranged in the region 110, four heat generating elements 36 are arranged in the region 120D, and two heat generating elements 36 are arranged in the region 120U.

  Further, in the present embodiment, the heat generating element 36 is provided such that the amount of heat generated increases from the upstream side to the downstream side of the refrigerant flow in the linear portion 41B, that is, in the order of the region 120U, the region 120D, and the region 110. It has been. The plurality of heat generating elements 36 are provided such that the arrangement density thereof increases in order from the upstream side to the downstream side of the refrigerant flow in the straight portion 41B, that is, in the order of the region 120U, the region 120D, and the region 110. If an arbitrary region having the same area as the region 110 of the straight portion 41B is defined on the rectifying partition wall 31p, the heat generation amount of the heat generating element 36 in the region is the heat generation amount of the heat generating element 36 in the region 110 of the straight portion 41B. Smaller than.

  The heating element 36 is also provided in the linear portion 41C in the same manner as the linear portion 41B. That is, the heating element 36 is a region where the amount of heat generated in the region 110 facing the opening 32 formed in the rectifying partition wall portion 31q in the straight portion 41C is opposed to the rectifying partition wall portion 31q and has the same area as the region 110. The heat generation amount at 120 is set to be larger.

  The cooling device 20 for the power control unit in the present embodiment further includes an element fixing plate 35 as an element fixing portion. The element fixing plate 35 is interposed between the heat generating element 36 and the rectifying partition wall 31. The heating element 36 is fixed to the rectifying partition wall 31 by an element fixing plate 35. That is, the element fixing plate 35 functions as an adhesive for fixing the heat generating element 36 to the rectifying partition wall 31. The element fixing plate 35 is formed of a material having high thermal conductivity and electrical insulation, for example, a resin sheet containing a filler having high thermal conductivity.

  The converters, inverters, and capacitors that make up the power control unit 60 have different operating voltages and different heat generation characteristics. Therefore, in order to separate the heating elements 36, the converters, inverters, and capacitors each have a separate rectifying partition wall 31. May be installed. Moreover, you may mount in each rectifying partition part 31 for every kind of element.

  Then, the effect | action and effect which are show | played by the cooling device 20 of the electric power control unit in this Embodiment are demonstrated. FIG. 4 is a cross-sectional view showing a refrigerant flow formed in the PCU case in FIG.

  Referring to FIGS. 3 and 4, heat generating element 36 generates heat in accordance with the operation of power control unit 60. In the cooling device 20 of the power control unit in the present embodiment, the heat generating element 36 is cooled by transferring heat from the heat generating element 36 to the refrigerant sealed in the PCU case 24.

  At this time, the refrigerant gradually reaches the linear portion 41A through the linear portion 41D, the linear portion 41C, and the linear portion 41B of the meandering passage 41 while gradually increasing in temperature due to heat received from the heating element 36. The refrigerant that has reached the straight portion 41A is cooled by exchanging heat with the radiator 26 that receives the traveling wind. The cooled refrigerant passes through the return passage 46 and again toward the straight portion 41D of the meandering passage 41. As described above, heat convection occurs in the refrigerant in the PCU case 24, and a circulation cycle of the refrigerant flow as shown by an arrow in FIG. 4 is formed in the circulation passage 40. The refrigerant efficiently cools the plurality of heat generating elements 36 while flowing through the meandering passage 41.

  In this way, when the refrigerant flows through the meandering passage 41, the refrigerant changes its direction at the bent portion 41E from the lower straight portion (for example, the straight portion 41B) toward the upper straight portion (for example, the straight portion 41A). And proceed. At this time, the pressure loss of the refrigerant flow becomes large at the bent portion 41E, and there is a concern that the flow velocity of the refrigerant decreases. On the other hand, in the present embodiment, the amount of heat generated by the heat generating element 36 in the region 110 facing the opening 32 is opposed to the rectifying partition wall 31 in the lower straight portion (for example, the straight portion 41B). Since the amount of heat generated by the heat generating element 36 in the region 120 is larger, the temperature of the refrigerant greatly increases immediately below the opening 32. Accordingly, the refrigerant can smoothly travel from the lower straight portion (for example, the straight portion 41B) to the upper straight portion (for example, the straight portion 41A) through the opening 32, and the refrigerant flow in the circulation passage 40 can be achieved. Speed can be improved.

  The meandering passage 41 in which the heating element 36 is disposed is formed by the rectifying partition wall 31. For this reason, the heat generated by the heating element 36 is mainly transmitted to the rectifying partition wall 31 through the element fixing plate 35 and is radiated by heat exchange between the rectifying partition wall 31 and the refrigerant. In the present embodiment, since electrical insulation between the plurality of heating elements 36 is ensured by the element fixing plate 35, the rectifying partition wall portion 31 can be formed of a metal having excellent thermal conductivity. Thereby, heat exchange between the rectifying partition wall 31 and the refrigerant can be promoted, and the cooling efficiency of the heating element 36 can be improved.

  Further, for example, when attention is paid to the rectifying partition wall portion 31q, straight portions 41B and 41C of the meandering passage 41 are formed on both sides of the rectifying partition wall portion 31q. In this case, the refrigerant exchanges heat with the rectifying partition wall portion 31q twice during the flow through the straight portion 41B and the straight portion 41C, and heat exchange between the refrigerant and the rectifying partition wall portion 31q is performed. Can be promoted. Thereby, the cooling efficiency of the heat generating element 36 can be improved.

  Further, when returning the refrigerant from the straight portion 41A of the meandering passage 41 to the straight portion 41D through the return passage 46, the refrigerant flow becomes smoother as the temperature of the refrigerant in the straight portion 41A is lower. On the other hand, when the return passage partition wall 33 has a thermal conductivity smaller than that of the rectifying partition wall 31p and the rectifying partition wall 31r, heat is transmitted from the rectifying partition wall 31r to the rectifying partition wall 31p. It can suppress and can set the temperature of the refrigerant | coolant in 41 A of linear parts lower. As a result, the speed of the refrigerant flow in the circulation passage 40 can be increased, and the cooling efficiency of the heat generating element 36 can be improved.

  Moreover, in this Embodiment, since the effect of a thermal convection is utilized for the circulation of a refrigerant | coolant, it is not necessary to provide the cooling device 20 with the mechanism for circulating refrigerant | coolants, such as a pump. For this reason, the cooling device 20 can be reduced in size and the manufacturing cost can be reduced.

  In the present embodiment, the refrigerant is pressurized to the saturated vapor pressure or higher and sealed in the PCU case 24. For this reason, air bubbles are not generated in the refrigerant received from the heat generating element 36, and there is no fear of discharge between the heat generating elements 36 due to the generation of the air bubbles. Thereby, it becomes possible to make it close between the heat generating elements 36 within the tolerance | permissible_range of the dielectric strength of a refrigerant | coolant, and the cooling device 20 can be reduced in size.

  The structure of the cooling device for electric equipment according to Embodiment 1 of the present invention described above will be described together. The cooling device 20 for the power control unit as the electric equipment in this embodiment is made of an electrically insulating refrigerant. A PCU case 24 as a sealed housing to be enclosed, a passage forming plate 30 as a passage forming member for forming a circulation passage 40 for circulating a refrigerant inside the PCU case 24, and a heating element provided in the circulation passage 40 36, and a radiator portion 26 as a heat radiating portion disposed on the PCU case 24 and disposed above the heat generating element 36 in the vertical direction. The passage forming plate 30 has a rectifying partition wall portion 31 as a plurality of partition wall portions arranged at intervals in the vertical direction.

  The circulation passage 40 has a straight portion 41A as an upper passage and a straight portion 41B as a lower passage. The straight portion 41B is partitioned from the straight portion 41A by the rectifying partition wall portion 31p, and is disposed below the straight portion 41A in the vertical direction. An opening 32 is formed in the rectifying partition wall 31p. The opening 32 communicates between the linear portion 41A and the linear portion 41B, and guides the refrigerant from the linear portion 41B to the linear portion 41A. In the linear portion 41B, the heat generating element 36 has a heat generation amount in the region 110 as the first region facing the opening 32, facing the rectifying partition wall 31p, and the region 120 as the second region having the same area as the region 110. It is provided so as to be larger than the heat generation amount.

  Alternatively, the circulation passage 40 has a straight portion 41B as an upper passage and a straight portion 41C as a lower passage. The straight portion 41C is partitioned from the straight portion 41B by the rectifying partition wall portion 31q, and is disposed below the straight portion 41C in the vertical direction. An opening 32 is formed in the rectifying partition wall 31q. The opening 32 communicates between the linear portion 41B and the linear portion 41C, and guides the refrigerant from the linear portion 41C to the linear portion 41B. In the linear portion 41C, the heat generating element 36 has a heat generation amount in the region 110 as the first region facing the opening 32 facing the rectifying partition wall portion 31q, and the region 120 as the second region having the same area as the region 110. It is provided so as to be larger than the heat generation amount.

  According to the cooling device 20 of the power control unit according to Embodiment 1 of the present invention configured as described above, a special device for circulating the refrigerant is not required, so that the cooling device is reduced in size and simplified. be able to. In addition, the refrigerant flow speed in the circulation passage 40 can be improved by setting the arrangement density of the heating elements 36 large in the region 110 facing the opening 32. Thereby, the heat generating element 36 which is a cooling target can be efficiently cooled.

  The present invention is applied to a power control unit mounted on a fuel cell hybrid vehicle (FCHV) or an electric vehicle (EV) using a fuel cell and a secondary battery as power sources. You can also. In the hybrid vehicle in the present embodiment, the internal combustion engine is driven at the fuel efficiency optimum operating point, whereas in the fuel cell hybrid vehicle, the fuel cell is driven at the power generation efficiency optimum operating point. The use of the secondary battery is basically the same for both hybrid vehicles.

  In addition, the electric device to which the present invention is applied is not limited to the power control unit, and the present invention is applied to various electric devices that require cooling of the heating elements.

(Embodiment 2)
FIG. 5 is a cross-sectional view showing a cooling device for a power control unit according to Embodiment 2 of the present invention. The power control unit cooling device in the present embodiment basically has the same structure as that of power control unit cooling device 20 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 5, in the present embodiment, a plurality of heat generating elements 36 are provided in linear portion 41A, and heat generating elements 36a, 36b, and 36c are provided in linear portions 41B and 41C. Yes.

  The mode in which the heating element 36a, the heating element 36b, and the heating element 36c are provided in the linear portion 41B will be described. The heating element 36a, the heating element 36b, and the heating element 36c are mounted on the rectifying partition wall 31q. The heat generating element 36a, the heat generating element 36b, and the heat generating element 36c are provided in order from the downstream side to the upstream side of the refrigerant flow in the linear portion 41B.

  A region 110 and a region 120 are defined in the straight line portion 41B. The region 110 is defined at a position facing the opening 32 formed in the rectifying partition wall 31p.

  The region 120 has the same area as the region 110 and is defined at an arbitrary position facing the rectifying partition wall 31p. In FIG. 5, a region 120D is defined at a position facing the rectifying partition wall 31p and including the heat generating element 36b, and a position facing the rectifying partition wall 31p and including the heating element 36c. An area 120U is defined in FIG. The region 120D has the same area as the region 110, and the region 120U has the same area as the region 110. The region 120U, the region 120D, and the region 110 are arranged in the order given from the upstream side to the downstream side of the refrigerant flow in the linear portion 41B.

  In the region 110, the heating element 36a is disposed. The heat generation amount of the heat generating element 36a is larger than the heat generation amount of the heat generating element 36b and larger than the heat generation amount of the heat generating element 36c. The heat generation amount of the heat generating element 36b is larger than the heat generation amount of the heat generating element 36c. Due to such a configuration, also in the present embodiment, the heating element 36 is provided in the linear portion 41B so that the heating amount of the heating element 36 in the region 110 is larger than the heating amount of the heating element 36 in the region 120. It is done.

  The heating element 36 is also provided in the linear portion 41C in the same manner as the linear portion 41B.

  According to the cooling device 20 of the power control unit in the second embodiment of the present invention configured as described above, the effect described in the first embodiment can be obtained in the same manner.

(Embodiment 3)
FIG. 6 is a sectional view showing a cooling device for a power control unit according to Embodiment 3 of the present invention. The power control unit cooling device in the present embodiment basically has the same structure as that of power control unit cooling device 20 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 6, in this embodiment, the rectifying partition walls 31 adjacent to each other have an area of a meandering passage 41 formed between the rectifying partition walls 31 (a meandering passage by a plane perpendicular to the refrigerant flow direction). (Passage area when 41 is cut) is arranged to be larger on the downstream side than on the upstream side of the refrigerant flow.

  More specifically, the rectifying partition wall 31q and the rectifying partition wall 31r are arranged such that the distance between them increases from the upstream side to the downstream side of the refrigerant flow. The rectifying partition wall 31p and the rectifying partition wall 31q are arranged such that the distance between them increases from the upstream side to the downstream side of the refrigerant flow. For example, when focusing on the rectifying partition wall 31q and the rectifying partition wall 31r adjacent to each other, the area of the straight portion 41C formed between the rectifying partition wall 31q and the rectifying partition wall 31r is the upstream side of the refrigerant flow. It becomes larger on the downstream side (S2) than (S1).

  According to such a configuration, the pressure of the refrigerant flowing through each linear portion of the circulation passage 40 is high on the upstream side of the refrigerant flow and low on the downstream side. Accordingly, the refrigerant easily flows from the upstream side to the downstream side of the circulation passage 40, and the cooling efficiency of the heat generating element 36 can be improved.

  In addition, the aspect in which the heat generating element 36 is provided in the linear portion 41B and the linear portion 41C is the same as that in the first embodiment.

  According to the cooling device for a power control unit in the third embodiment of the present invention configured as described above, the effect described in the first embodiment can be obtained in the same manner.

(Embodiment 4)
FIG. 7 is a cross-sectional view showing a cooling device for a power control unit according to Embodiment 4 of the present invention. The power control unit cooling device in the present embodiment basically has the same structure as that of power control unit cooling device 20 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 7, the cooling device for the power control unit in the present embodiment further includes an element mounting base 48. The element mounting base 48 is disposed in the circulation passage 40. The element mounting base 48 is disposed in the meandering passage 41. The element mounting base 48 is disposed on the straight portion 41B, the straight portion 41C, and the straight portion 41D. The element mounting base 48 is formed of a material having high thermal conductivity and electrical insulation, for example, a resin plate material containing a filler having high thermal conductivity.

  The element mounting base 48 is disposed at a position spaced apart from the rectifying partition wall 31. The element mounting base 48 arranged in the straight line portion 41B is provided between the rectifying partition wall portion 31p and the rectifying partition wall portion 31q. The element mounting base 48 disposed in the straight line portion 41C is provided between the rectifying partition wall portion 31q and the rectifying partition wall portion 31r. The element mounting base 48 disposed in the straight line portion 41D is provided between the rectifying partition wall portion 31r and the bottom portion 24b of the PCU case 24. Each element mounting table 48 is supported by a mounting table supporting spacer 49 extending from the rectifying partition wall 31 or the PCU case 24.

  The heating element 36 is mounted on the element mounting base 48 thus provided. A mode in which the heating element 36 is provided in the straight portion 41B, the straight portion 41C, and the straight portion 41D is the same as that in the first embodiment.

  The flow rate of the refrigerant flowing in the meandering passage 41 is low in the vicinity of the rectifying partition wall 31 or the PCU case 24 due to the viscous friction of the refrigerant, and increases as the distance from the rectifying partition wall 31 or the PCU case 24 increases. In the present embodiment, by mounting the heat generating element 36 on the element mounting base 48, the heat generating element 36 can be positioned in the meandering passage 41 at a position where the flow rate of the refrigerant becomes high. Thereby, the cooling efficiency of the heat generating element 36 can be improved.

  For the above reasons, the element mounting base 48 is preferably provided at a position where the distances from the rectifying partition walls 31 disposed above and below are equal.

  According to the cooling device for a power control unit in the fourth embodiment of the present invention configured as described above, the effect described in the first embodiment can be obtained similarly.

  Note that a new power control unit cooling device may be configured by appropriately combining the power control unit cooling device structures in the first to fourth embodiments described above. For example, in the cooling device for the power control unit in the third and fourth embodiments, the heating element 36 may be provided in the same manner as in the second embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to a cooling structure of various electric devices having a heating element.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 15 Engine room, 20 Cooling device, 24 PCU case, 24b Bottom part, 24t Top part, 26 Radiator part, 30 Passage formation board, 31m Upper surface, 31n Lower surface, 31, 31p, 31q, 31r Rectifying partition part, 32 Opening portion, 33 passage partition portion, 35 element fixing plate, 36, 36a, 36b, 36c heating element, 38, 39 partition portion support spacer, 40 circulation passage, 41 meandering passage, 41A, 41B, 41C, 41D straight portion, 41E bending part, 46 return path, 48 element mounting base, 49 mounting base support spacer, 50 high voltage power storage device, 52, 54 motor generator, 56 low voltage power storage device, 58 LV equipment, 60 power control unit, 62, 66, 74 Smoothing capacitor, 64 HV converter, 68, 70 Invar Motor, 72 LV converter, 110,120,120D, 120U region.

Claims (9)

A sealed casing in which an electrically insulating refrigerant is enclosed;
A passage forming member having a plurality of partition walls arranged at intervals in the vertical direction, and forming a circulation passage for circulating the refrigerant in the sealed casing;
A heating element provided in the circulation passage;
Arranged above the heat generating element in the vertical direction, and provided with a heat dissipating part provided in the sealed casing,
The circulation passage has an upper passage, and a lower passage that is partitioned from the upper passage by the partition wall and is disposed on the lower side in the vertical direction than the upper passage,
The partition wall portion is formed with an opening that communicates between the upper passage and the lower passage and guides the refrigerant from the lower passage to the upper passage.
In the lower passage, the heat generating element is configured such that the amount of heat generated in the first region facing the opening is greater than the amount of heat generated in the second region facing the partition and having the same area as the first region. A cooling device for electrical equipment provided in   2. The cooling device for an electric device according to claim 1, wherein the plurality of heating elements are arranged in the lower passage so that an arrangement density thereof is larger in the first region than in the second region. The plurality of partition walls include a first partition wall and a second partition wall disposed adjacent to each other,
In the first partition wall and the second partition wall, the area of the circulation passage formed between the first partition wall and the second partition wall is larger on the downstream side than on the upstream side of the refrigerant flow. The cooling device for an electric device according to claim 1 or 2, wherein   The cooling device for an electric device according to any one of claims 1 to 3, wherein the plurality of partition walls are arranged such that the circulation passage extends while meandering from the lower side to the upper side in the vertical direction. The plurality of partition walls include a third partition wall disposed on the uppermost side in the vertical direction among the plurality of partition walls, and a fourth partition wall disposed on the lowermost side in the vertical direction,
The passage forming member further includes a return passage partition that extends between the third partition and the fourth partition and returns the coolant cooled by the heat radiating portion to the upstream side of the coolant flow. Have
5. The cooling device for an electric device according to claim 1, wherein the return passage partition wall portion has a thermal conductivity smaller than that of the third partition wall portion and the fourth partition wall portion.   The said heat generating element is a cooling device of the electric equipment of any one of Claim 1 to 5 mounted in the said partition part. Further comprising an element fixing portion interposed between the partition wall and the heating element, for fixing the heating element to the partition wall;
The said element fixing | fixed part is a cooling device of the electric equipment of Claim 6 formed with the material which has electrical insulation.   The cooling device for an electrical device according to any one of claims 1 to 7, further comprising an element mounting base provided in the circulation passage at a position spaced apart from the partition wall and on which the heating element is mounted.   The cooling device for an electric device according to any one of claims 1 to 8, wherein the refrigerant is pressurized to a saturation vapor pressure or higher and sealed in the sealed casing.

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