JP2011238722A - Electrical device cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical device cooling system which can cool an electrical device without the need for a specifically-engineered device for circulating refrigerant.SOLUTION: An electrical device cooling system 10 includes: a sealed housing 12 having a heat-releasing part 14 in an upper portion in the direction of gravity; multiple stages of element-mounting tables 18 to put elements 19 to be cooled, placed along a vertical direction in the sealed housing 12; electrically insulative refrigerant 20 sealed in the sealed housing 12; and a flow-channel barrier wall 16 provided in a meandering manner relative to the vertical direction between the multiple stages of element-mounting tables 18, and forming a circulation flow channel for the refrigerant to flow upward owing to convection resulting from heat generation by the element to be cooled, to be cooled by the heat-releasing part, and to go back downward. The refrigerant 20 is pressurized to a saturation vapor pressure or higher and sealed in the sealed housing 12.

Description

  The present invention relates to an electric equipment cooling apparatus, and more particularly, to an electric equipment cooling apparatus that cools a substrate on which an electric equipment housed in a housing is mounted.

  For example, a vehicle equipped with a rotating electrical machine is provided with various electrical devices such as a power supply circuit connected to the rotating electrical machine. Since these electric devices generate heat with the operation thereof, the cooling is performed.

  For example, Patent Document 1 uses a cooling body having a structure in which a plurality of parallel refrigerant flow paths are connected by bent flow paths as a cooling body that circulates water cooled by a pump as cooling of an electronic device. By reducing the flow volume from the refrigerant flow path toward the downstream flow path in order and increasing the speed of the refrigerant in the downstream flow path as compared to the upstream flow path, it is bent with a uniform flow area. However, it is stated that the overall thermal resistance and pressure loss are reduced.

  Further, in Patent Document 2, as a module heat dissipation structure, one side opening of the casing is sealed with a radiator with fins, a protrusion is provided on the inner periphery of the opposite opening, and the bottom header of the module is fixed by crimping. Discloses a structure in which an inert refrigerant is sealed.

  Patent Document 3 discloses a structure in which the periphery of a memory module is sealed with a polyimide film and filled with an inert liquid or a gel substance as a cooling structure of the memory module.

  Further, in Patent Document 4, as a heat dissipation structure, a device that generates heat in an inverter of an electric vehicle is bonded to one surface of an aluminum or copper metal foil having a thickness of about 0.3 mm by a lead-tin-based judgment material. It is stated that the other surface of the metal foil is cooled in direct contact with the refrigerant.

  Further, in Patent Document 5, as a boiling refrigerant type cooling device, a refrigerant boiling part of an airtight container in which an electric device such as a semiconductor stack is immersed in a boiling refrigerant such as Freon 113 and the refrigerant evaporates by heat loss of the electric device. And a refrigerant condensing part that condenses by cooling and condensing in the vapor phase of the refrigerant that has been boiled and vaporized, and cooling the electrical equipment using circulation involving a phase change of the gas-liquid phase of the refrigerant. It is stated.

International Publication No. 00/16397 Japanese Utility Model Publication No. 1-73996 Japanese Patent Laid-Open No. 5-102359 JP 2005-116578 A Japanese Patent Publication No. 3-29181

  As described in Patent Document 1, a pump that circulates cooling water is often used for cooling electronic devices. In this case, it is necessary to provide a pump for cooling. Since Patent Document 5 uses a circulation accompanied by a gas-liquid phase change of a boiling refrigerant, a pump is not required, but if an electric device is operated under a high voltage due to bubbles generated by boiling, there is a risk of causing a discharge. . If the refrigerant is simply sealed as in Patent Documents 2 and 3, the cooling effect may be insufficient.

  An object of the present invention is to provide an electric device cooling apparatus suitable for cooling an electric device without requiring a special device for circulating a refrigerant.

  The electrical equipment cooling device according to the present invention is equipped with a sealed casing having a heat radiating portion on the upper side in the direction of gravity and an element to be cooled, and a plurality of elements mounted in the vertical direction in the sealed casing Between the base, the electrically insulating refrigerant sealed in the hermetically sealed housing, and the multi-stage element mounting base, it is provided meandering in the vertical direction, and the refrigerant flows upward by convection due to heat generated by the element to be cooled. And a flow path partition that forms a circulation flow path that is cooled by the heat radiating section and returns downward.

  Further, in the electrical equipment cooling device according to the present invention, the flow path partitioning section is configured such that the upstream pressure of the refrigerant circulation is higher than the downstream pressure for each flow path between the meandering bends. It is preferable to provide a difference between the upstream channel cross-sectional area and the downstream channel cross-sectional area.

  Moreover, in the electric equipment cooling device according to the present invention, it is preferable that the refrigerant is pressurized to a saturation vapor pressure or higher and sealed in a sealed casing.

  With the above-described configuration, the electric device cooling apparatus includes a plurality of element mounting bases arranged in the vertical direction in a sealed casing that has a heat radiating portion on the upper side in the direction of gravity and encloses the refrigerant. Between the mounting bases, a flow path partition section is provided which is provided meandering in the vertical direction and forms a circulation flow path in which the refrigerant flows upward by convection due to heat generated by the element to be cooled and is cooled by the heat radiating section and returns downward. Prepare. In this way, the refrigerant circulates by convection in the meandering flow path partition wall portion to cool the element to be cooled, so that no special equipment for circulating the refrigerant is required.

  Further, in the electrical equipment cooling device, the flow path partitioning section is configured so that the upstream side pressure of the refrigerant circulation is higher than the downstream pressure for each flow path between the meandering curved parts. Since a difference is provided between the cross-sectional area of the passage and the cross-sectional area of the downstream side, the refrigerant easily flows toward the downstream side, circulation is promoted, and heat dissipation is improved.

  Further, in the electric device cooling apparatus, since the refrigerant is pressurized and sealed above the saturated vapor pressure, no bubbles are generated even if the refrigerant is heated by the heat generated by the element to be cooled. Therefore, even if an electric device composed of elements operates under a high voltage, there is no risk of discharge through the air gap.

It is a figure which shows a mode that the electric equipment cooling device of embodiment which concerns on this invention is mounted in a vehicle. It is a figure explaining the structure of the electric equipment cooling device of embodiment which concerns on this invention. It is a figure explaining the other structural example.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Below, what is mounted in a hybrid vehicle is demonstrated as an electric air apparatus cooling device, However, This is an illustration and may be mounted in vehicles other than a hybrid vehicle. For example, it may be mounted on an electric vehicle equipped with a fuel cell. Moreover, you may use in order to cool electric equipment other than a vehicle use.

  In addition, a converter, an inverter, and a smoothing capacitor will be described as the electric device accommodated in the casing of the electric device cooling device, but other electric devices, electric circuits, electronic elements, and the like may be used. The element mounting base on which the elements constituting the electrical equipment are mounted will be described as being arranged in three stages, but any structure can be used as long as it can form a flow path through which the refrigerant circulates. The number of arrangement stages is not limited.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram for explaining a state of the electric device cooling apparatus 10 mounted on the hybrid vehicle 6. The hybrid vehicle 6 is a vehicle on which an internal combustion engine and a rotating electric machine are mounted as a drive source, and the electric device cooling device 10 is an element mounting base on which elements constituting an electric device such as an electric circuit provided in the hybrid vehicle 6 are mounted. Is a device having a function of cooling an electrical device or an element constituting the electrical device as a cooling target.

  The electrical equipment cooling device 10 forms a refrigerant flow path in a meandering shape, a heat dissipating part 14 provided in the upper part of the closed case 12, a refrigerant 20 enclosed in the inside of the closed case 12, and a serpentine shape. It is configured to include a flow path partition 16 and an element mounting base 18 on which an element 19 to be cooled is mounted. The electric equipment cooling device 10 is disposed in the engine room 8 in the hybrid vehicle 6 where the internal combustion engine and the rotating electrical machine are disposed. Of course, it may be arranged in a place other than the engine room 8.

  FIG. 2 is a detailed structural diagram of the electrical device cooling apparatus 10 and a configuration diagram of the power supply circuit 60 for explaining the contents of the electrical device accommodated therein and elements constituting the electrical device. First, the contents of the power supply circuit 60 will be described. The power supply circuit 60 supplies the DC power of the high voltage power storage device 50 and the low voltage power storage device 56 to the two rotating electrical machines 52 and 54 that operate with high voltage AC power and the LV equipment 58 that operates with low voltage. It is a circuit having a function of converting to a state suitable for operation, such as voltage and alternating current, and supplying it. Conversely, for example, the regenerative electric power from the two rotating electric machines 52 and 54 is also converted into a voltage suitable for the high voltage power storage device 50 and direct current and charged.

  The high voltage power storage device 50 connected to the power supply circuit 60 is a chargeable / dischargeable high voltage secondary battery. As such a high voltage power storage device 50, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200 V to about 300 V, or a capacitor can be used. The low voltage power storage device 56 is a chargeable / dischargeable low voltage secondary battery. As such a low voltage power storage device 56, a lead storage battery or the like having a nominal voltage of 12V to 14V can be used.

  The two rotating electric machines 52 and 54 connected to the power supply circuit 60 are motor generators (M / G) mounted on the vehicle, functioning as motors when electric power is supplied, and as generators during braking. It is a functioning three-phase synchronous rotating electric machine.

  In FIG. 1, the two rotating electric machines 52 and 54 are distinguished from each other, and the rotating electric machine 52 indicated as MG1 and the rotating electric machine 54 indicated as MG2 are illustrated. Here, the rotating electrical machine 52 shown as MG1 is connected to the engine, and is mainly used as a generator to generate AC power, and is converted into DC power by an MG1 inverter 68 described later, whereby the high-voltage power storage device 50 is converted. Has the function of charging. The rotating electrical machine 54 shown as MG2 is mainly used for driving driving during powering of the vehicle, and has a function of operating the DC power of the high-voltage power storage device 50 by AC power converted by the inverter 70 for MG2. The rotating electrical machine 54 also has a function of recovering the regenerative energy during braking of the vehicle, converting it into DC power by the MG2 inverter 70, and charging the high voltage power storage device 50. At this time, the rotating electrical machine 54 functions as a generator.

  An LV device 58 connected to the power supply circuit 60 in parallel with the low-voltage power storage device 56 is a device that operates with the voltage of the low-voltage power storage device 56, such as audio devices, lighting devices, small motors, and microprocessors. Electronic devices and electric circuits.

  The power supply circuit 60 is for MG1 connected to smoothing capacitors 62, 66, 74, an HV converter 64 that is a high voltage side voltage converter, an LV converter 72 that is a low voltage side voltage converter, and a rotating electrical machine 52. The inverter 68 and the inverter 70 for MG2 connected to the rotary electric machine 54 are comprised.

  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 two 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.

  The HV converter 64 is provided between the high voltage power storage device 50 and the two inverters 68 and 70, and performs voltage conversion between the terminal voltage of the high voltage power storage device 50 and the voltage on the two inverters 68 and 70 side. This is a converter circuit having a function. As the HV converter 64, a converter including a reactor and a switching element can be 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 a converter circuit. As the LV converter 72, a converter including a reactor and a switching element can be used.

  The two inverters 68 and 70 convert the high-voltage DC power into AC three-phase drive power and supply it to the rotating electrical machines 52 and 54, and conversely, the AC three-phase regenerative power from the rotating electrical machines 52 and 54 is converted into the high voltage. This circuit has a function of converting to DC charging power. In FIG. 2, it corresponds to distinguishing the two rotating electric machines 52 and 54 as shown as MG1 and MG2, and the one connected to the rotating electric machine 52 shown as MG1 is shown as an inverter 68 and MG2 for MG1. The one connected to the rotating electrical machine 54 is an inverter 70 for MG2. The two inverters 68 and 70 can be configured by a circuit including a switching element and a diode.

  As described above, the components of the power supply circuit 60 accommodated in the electric device cooling apparatus 10 can be broadly divided into converters, inverter electric devices, and capacitors. However, converters and inverter electric devices are switching elements, Since it is composed of diode and reactor elements, the constituent elements of the power supply circuit 60 are eventually composed of a plurality of elements. Since these elements generate heat when actuated, the object to be cooled by the electric device cooling apparatus 10 can also be referred to as an electric device, and can also be referred to as a plurality of elements constituting the electric device. Hereinafter, unless otherwise specified, the description will be made assuming that the cooling target is an element.

  Next, the content of the electric equipment cooling device 10 will be described. The sealed casing 12 of the electric device cooling apparatus 10 is a container that becomes a sealed space in which the internal space is blocked from the outside. Specifically, the sealed casing 12 can be configured using a lower container body and an upper container body that can be combined with each other to form an airtight space.

  The heat dissipating part 14 is provided on the upper side of the sealed casing 12 in the gravity direction, and is a part having a heat dissipating function for exchanging heat with the outside air as a radiator. Specifically, it is a portion where the heat radiation fin is provided.

  The channel partition 16 is a plurality of space partition members arranged so that a meandering coolant channel is formed in the vertical direction inside the sealed casing 12. In the example of FIG. 2, the flow path partition 16 is configured by a U-shaped member and a plate material inserted into the U-shaped opening. In other words, the flow path partition 16 is a plurality of members that form a circulation flow path in which the refrigerant 20 flows upward by convection due to heat generated by the element 19 to be cooled, is cooled by the heat radiating unit 14, and returns downward. The vertical direction is a direction parallel to the gravitational direction, and the upper direction is the side opposite to the ground surface side when the ground surface side is downward along the gravity direction.

  The plurality of partition wall support spacers 24 support the flow path partition wall portion 16 with respect to the sealed housing 12 so that a meandering flow path is formed by the inner wall of the sealed housing 12 and the flow path partition wall portion 16. A plurality of support members having a function of

  The element mounting base 18 is a substrate on which an element 19 to be cooled is mounted. As described above, since the power supply circuit 60 is composed of a plurality of elements, these elements are separately mounted on the plurality of element mounting bases 18. In the example of FIG. 2, the elements are mounted separately on three element mounting bases 18. The converters, inverters, and capacitors that constitute the power supply circuit 60 have different operating voltages and different heat generation characteristics. Therefore, in order to separate the elements, it is preferable to divide each block of the power supply circuit 60. Moreover, you may divide for every kind of element. For example, a plurality of capacitors may be combined on one element mounting base 18, and switching elements may be combined on another element mounting base 18.

  The element mounting base 18 is disposed in a meandering flow path formed by the sealed casing 12 and the flow path partitioning section 16. In other words, the channel partition 16 is a member that forms a circulation channel that is provided meandering in the vertical direction between a plurality of element mounting bases. In the example of FIG. 2, one element mounting base 18 is disposed in each of the three flow path portions of the meandering circulation flow path. From another point of view, inside the sealed casing 12, from the bottom to the ceiling, the bottom of the sealed casing 12, the element mounting base 18, the flow path partitioning section 16, the element mounting base 18, the flow path. The element mounting base 18 and the flow path partitioning section 16 are alternately arranged such that the partitioning section 16, the element mounting base 18, the flow path partitioning section 16, and the ceiling portion of the sealed casing 12.

  The refrigerant 20 is a cooling fluid sealed in a sealed casing, and a fluid excellent in electrical insulation and thermal conductivity is used. As the refrigerant 20, a fluorine-based inert liquid can be used. The refrigerant 20 is pressurized to the saturated vapor pressure or higher and sealed in the sealed casing 12. By doing in this way, even if the refrigerant | coolant 20 is heated by the heat_generation | fever of the element 19 to be cooled, a bubble can be generated. Thereby, even if an electric device such as an inverter or a converter is operated at a high voltage, it is possible to prevent the element 19 from being affected by damage or the like due to the discharge due to the air gap.

  The electric device cooling apparatus 10 having such a configuration has the following operation. In other words, when the element 19 to be cooled mounted on the element mounting base 18 disposed inside the sealed casing 12 is activated, these elements generate heat. The refrigerant 20 is warmed by the heat generation, and flows upward while meandering along the meandering flow path by convection. And if it flows to the uppermost part inside the airtight housing | casing 12, heat exchange with external air will be performed in the thermal radiation part 14, and it will cool and will return below. The cold refrigerant 20 returned to the lower side is heated while cooling the element 19 that generates heat, and the circulation due to the rise in convection and the cooling in the heat radiating portion 14 is repeated as described above.

  Thus, the element 19 to be cooled can be cooled without requiring a special device for circulating the refrigerant 20. Further, since the refrigerant 20 is pressurized to the saturated vapor pressure or higher and sealed in the sealed casing 12, no bubbles are generated even if the refrigerant 20 is heated by the heat generated by the element 19.

  FIG. 3 is a diagram showing a configuration of the electric device cooling apparatus 80 that can circulate the refrigerant 20 more efficiently. In the electric device cooling apparatus 10 of FIG. 2, the bottom surface portion and the ceiling portion inside the sealed casing 12 are parallel to each other and in the horizontal direction. And the flow-path partition part 16 is comprised by the member arrange | positioned in parallel with the bottom face part and ceiling part of the airtight housing | casing 12, and the member arrange | positioned perpendicularly to this. That is, the meandering flow path formed by the flow path partition wall 16 is such that the refrigerant 20 is parallel to or perpendicular to the horizontal direction. And the flow-path cross-sectional area of the upstream which the refrigerant | coolant 20 flows about the flow-path part which flows in the horizontal direction, and the flow-path cross-sectional area of a downstream are the same.

  On the other hand, the flow path partition wall portion 86 of the electric device cooling device 80 of FIG. 3 is inclined from the horizontal direction, and the flow path cross section 88 on the upstream side in which the refrigerant 20 flows with respect to the flow path portion flowing in the horizontal direction. There is a difference between the downstream cross-sectional area 89. Correspondingly, the dimensions of the partition support spacer 84 are also different from those in FIG.

  The difference between the upstream-side channel cross-sectional area 88 and the downstream-side channel cross-sectional area 89 is set so that the upstream pressure in the circulation of the refrigerant 20 is higher than the downstream pressure. That is, the upstream-side channel cross-sectional area 88 is set smaller than the downstream-side channel cross-sectional area 89. As a result, the refrigerant 20 becomes easier to flow from the upstream side to the downstream side of the circulation, and the cooling performance is improved.

  The electrical equipment cooling device according to the present invention can be used for cooling electrical equipment including an element that generates heat.

  6 Hybrid Vehicle, 8 Engine Room, 10, 80 Electric Equipment Cooling Device, 12 Sealed Case, 14 Heat Dissipation Part, 16, 86 Channel Partition Part, 18 Element Mount, 19 Element, 20 Refrigerant, 24, 84 Partition Support Spacer 50, high voltage power storage device, 52, 54 rotating electrical machine, 56 low voltage power storage device, 58 LV equipment, 60 power supply circuit, 62, 66, 74 smoothing capacitor, 64 HV converter, 68, 70 inverter, 72 LV converter, 88 ( (Upstream side) Channel cross-sectional area, 89 (Downstream side) Channel cross-sectional area.

Claims (3)

A sealed housing having a heat dissipation part on the upper side in the direction of gravity;
A plurality of element mounting bases on which elements to be cooled are mounted and arranged vertically in a sealed housing;
An electrically insulating refrigerant sealed in a sealed housing;
A flow that is provided meandering in the vertical direction between the multi-stage element mounting bases, so that the refrigerant flows upward by convection due to heat generated by the element to be cooled and forms a circulation flow path that is cooled by the heat radiating portion and returns downward. A partition wall,
An electrical equipment cooling device comprising: In the electric equipment cooling device according to claim 1,
The channel partition is
For each flow path between meandering bends, there is a difference between the upstream flow path cross-sectional area and the downstream flow path cross-sectional area so that the upstream pressure of the refrigerant circulation is higher than the downstream pressure. An electrical equipment cooling device characterized by comprising: In the electric equipment cooling device according to claim 1,
The electrical equipment cooling device, wherein the refrigerant is pressurized to a saturation vapor pressure or higher and sealed in a sealed casing.

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