Heat dissipation device and power converter

Abstract

The present application provides a heat dissipation device, which includes an evaporator and a condenser; the evaporator includes a housing and a partition board. The housing has a sealed inner cavity, and the partition board divides the inner cavity into a first sub-cavity and a second sub-cavity. A first pipeline is connected to the first sub-cavity, and a second pipeline is connected to the second sub-cavity; a heating element is also fixed in the first sub-cavity. The partition board is provided with a diversion hole communicating between the first sub-cavity and the second sub-cavity, and the diversion hole is arranged facing the heating element. The cooling working medium in the condenser is transported to the second sub-cavity through the second pipeline. The cooling working medium flows into the first sub-cavity through the diversion hole, dissipates heat from the heating element, and then flows back to the condenser through the first pipeline for cooling. The heat dissipation device of the present application ensures its full contact with the heating element by defining the flow path of the cooling working medium, thereby improving the heat dissipation effect of the heat dissipation device. The present application also provides several heat dissipation devices, as well as a power converter including the above heat dissipation device.

Description

Technical Field

[0001] This application relates to the field of electronic devices, and particularly to a heat dissipation device and a power converter including the heat dissipation device. Background Art

[0002] Power converters such as inverters, motor drivers, and uninterruptible power supplies, etc., mostly use power semiconductor devices for power conversion. With the development of the integration and miniaturization of power semiconductor devices, the heat generation and energy consumption of power semiconductor devices gradually increase, and it is necessary to improve the heat dissipation capacity of the heat dissipation device in the power converter to match the working requirements of the power semiconductor devices. Summary of the Invention

[0003] This application provides a heat dissipation device and a power converter including the heat dissipation device. By specifically setting the internal structure of the heat dissipation device, the heat dissipation capacity for power semiconductor devices is improved. The specific technical solutions of this application are as follows:

[0004] In a first aspect, this application provides a heat dissipation device, which includes an evaporator and a condenser, and a first pipeline and a second pipeline respectively connected between the evaporator and the condenser; the evaporator includes a housing and a partition board, the housing has a sealed inner cavity, the partition board divides the inner cavity into a first sub-cavity and a second sub-cavity, the first pipeline is connected to the first sub-cavity, and the second pipeline is connected to the second sub-cavity; a heating element is also fixed in the first sub-cavity, and the partition board is provided with a diversion hole for communicating the first sub-cavity and the second sub-cavity, and at least part of the diversion hole is directly opposite to the heating element located in the first sub-cavity. The cooling working medium in the condenser is transported to the second sub-cavity through the second pipeline, the cooling working medium flows into the first sub-cavity through the diversion hole, after dissipating heat from the heating element, it returns to the condenser through the first pipeline for cooling.

[0005] The heat dissipation device provided in the first aspect of this application forms a circulation channel through the evaporator, the first pipeline, the condenser, and the second pipeline for the cooling working medium to circulate in the circulation channel. Among them, the cooling working medium dissipates heat from the heating element in the evaporator, then is cooled in the condenser, and then returns to the evaporator.

[0006] The heat dissipation device of this application also limits the flow path of the cooling working medium through the setting of the partition board. When the cooling working medium enters the first sub-cavity from the second sub-cavity, because at least part of the diversion hole is directly opposite to the heating element, it can ensure that the cooling working medium can dissipate heat from the heating element through a shorter flow path, so as to ensure the heat dissipation effect of the heat dissipation device of this application on the heating element.

[0007] In a possible implementation, the cooling working fluid in the condenser is transported to the second sub-chamber through the second pipeline under the action of gravity. The cooling working fluid flows into the first sub-chamber through the diversion holes against the direction of gravity. After dissipating heat from the heating element, it flows back to the condenser against the direction of gravity through the first pipeline for cooling.

[0008] In this implementation, the condenser is located above the evaporator along the direction of gravity. The cooling working fluid can be a gas-liquid two-phase cooling working fluid, such as a coolant or water. When the cooling working fluid is transported to the second sub-chamber through the second pipeline under the action of gravity, the cooling working fluid can be in a liquid state; while after the cooling working fluid dissipates heat from the heating element, it can be converted into a gaseous state, and then flow back into the condenser against the direction of gravity through the first pipeline. The heat dissipation device of the present application can form the form of a gravity heat pipe, and realize the circulating flow of the cooling working fluid through its own phase change, reducing energy consumption.

[0009] In a possible implementation, the condenser is provided with a liquid inlet communicating with the first pipeline and a liquid outlet communicating with the second pipeline. The liquid inlet is located above the liquid outlet along the direction of gravity.

[0010] In this implementation, the cooling working fluid entering the condenser from the first pipeline has a higher temperature and can flow back from the evaporator at a lower position in the direction of gravity to the condenser above. When the cooling working fluid is cooled in the condenser, it then flows back to the evaporator from the liquid outlet at a lower position in the direction of gravity.

[0011] In a possible implementation, the diversion holes include a plurality of diversion sub-holes. The plurality of diversion sub-holes are arranged at intervals and are located between the heating element and the partition plate.

[0012] In this implementation, the arrangement of the plurality of diversion sub-holes can enable the cooling working fluid to flow into the first sub-chamber relatively evenly and form a better cooling effect on the heating element. On the other hand, when the size of the diversion sub-holes is set relatively small, the diversion sub-holes can also function to block bubbles, prevent the bubbles in the second sub-chamber from entering the first sub-chamber along with the cooling working fluid, and avoid the bubbles from affecting the heat dissipation effect of the cooling working fluid on the heating element.

[0013] In a possible implementation, the heating element at least includes a first heating element and a second heating element. The second heating element is located between the first heating element and the partition plate. The housing further includes a current-limiting plate. The current-limiting plate is located between the first heating element and the second heating element. A plurality of through holes and slits are provided on the current-limiting plate. The holes and slits are used to block the bubbles flowing towards the first heating element.

[0014] In this implementation, multiple heating elements can be arranged inside the housing, and at least two heating elements are arranged in the same direction and spaced apart from each other. The cooling working medium flows through the second heating element and the first heating element in sequence, and dissipates heat from the second heating element and the first heating element in sequence. Since bubbles may be generated when the cooling working medium dissipates heat from the second heating element, and the bubbles will flow towards the first heating element along with the cooling working medium, a current-limiting plate is provided between the first heating element and the second heating element, and slits are formed to block the bubbles, so as to ensure that the cooling working medium passes through the slits to dissipate heat from the first heating element, and to avoid affecting the heat dissipation effect due to the contact between the bubbles and the first heating element.

[0015] In a possible implementation, the housing further includes a current-limiting wall, which is fixedly connected to the current-limiting plate and is located on at least one side of the first heating element. The current-limiting wall is also used to block the bubbles flowing towards the first heating element.

[0016] In this implementation, the current-limiting wall extends in a direction perpendicular to the current-limiting plate and is located on one side of the first heating element. When the bubbles blocked by the current-limiting plate flow towards the side direction of the first heating element, the current-limiting wall can also block the bubbles from contacting the first heating element from the side, thereby ensuring the heat dissipation effect of the first heating element.

[0017] In a possible implementation, the number of current-limiting walls is two, and the two current-limiting walls are respectively arranged on the opposite sides of the first heating unit and are fixedly connected to the opposite ends of the current-limiting wall respectively.

[0018] In a possible implementation, the first sub-chamber is located above the second sub-chamber along the direction of gravity.

[0019] In a possible implementation, the housing includes a front cover and a rear cover that are fixedly spaced apart, and the current-limiting plate and / or the current-limiting wall are simultaneously fixedly connected to the front cover and the rear cover.

[0020] In a possible implementation, a plurality of through slits are also provided on the current-limiting wall.

[0021] In this implementation, the arrangement of the slits on the current-limiting wall can also achieve the effect of blocking bubbles, and at the same time allow the cooling working medium on the side to pass through the current-limiting wall and act on the first heating element.

[0022] In a possible implementation, the housing includes a front cover and a rear cover that are fixedly spaced apart, and a plurality of support columns spaced apart from each other are further provided in the inner cavity. The heating element is fixed to the front cover or the rear cover, and the opposite ends of each support column are respectively fixedly connected to the front cover and the rear cover. The support columns are used to improve the structural stability of the housing.

[0023] In this implementation manner, the support columns can be located around the heating element and are connected between the front cover and the rear cover to enhance the structural stability of the housing. On the other hand, the arrangement of the support columns can also form a certain diversion and shunt effect on the cooling medium, making the flow of the cooling medium in the inner cavity more uniform and sufficient.

[0024] In a possible implementation manner, the heating element is fixed to the inner side wall of one of the front cover and the rear cover, and the inner side wall of the other cover is provided with a fitting area. The position of the fitting area is at least partially aligned with the heating element. The fitting area is provided with bumps, and the bumps protrude towards the heating element and are in contact with the heating element. The bumps also have pores, and the pores are at least located on the end faces of the bumps in contact with the heating element.

[0025] In this implementation manner, the heat dissipation device also enables the pores of the bumps on the fitting area to abut against and contact the heating element through the setting of the bumps, so that the cooling medium can form more nucleation points on the surface of the heating element, thereby promoting the heat dissipation effect of the cooling medium on the heating element.

[0026] In a possible implementation manner, there is a first distance between any two adjacent support columns. The pores of the bumps are formed by irregular arrangement of a plurality of holes, and the inner diameter size of any hole is smaller than the first distance.

[0027] In a possible implementation manner, there is a first distance between any two adjacent support columns. The bumps include a plurality of protruding portions arranged at intervals, and the gaps between the plurality of protruding portions form pores. The distance between any two adjacent protruding portions is smaller than the first distance.

[0028] In the above two implementation manners, the pores on the bumps can be formed by a plurality of holes or by a plurality of protruding portions arranged at intervals. And the interval distance of the pores is smaller than the interval distance between the support columns, thereby ensuring that the positions of the nucleation points are located at the pores and avoiding affecting the heat dissipation effect of the cooling medium on the heating element due to too small a distance between the support columns.

[0029] In a possible implementation manner, the housing is provided with a first communication hole and a second communication hole. The first pipeline is communicated to the inner cavity through the first communication hole, and the second pipeline is communicated to the inner cavity through the second communication hole. The first communication hole is located above the second communication hole along the gravity direction.

[0030] In this implementation manner, the cooled cooling medium can present a gas-liquid two-phase mixed state. At this time, the gaseous cooling medium will flow upward in the inner cavity, and thus can enter the first pipeline through the relatively high-positioned first communication hole and flow back to the condenser for cooling.

[0031] In a possible implementation manner, the first communication hole is located at the top of the housing along the gravity direction.

[0032] In a possible implementation, the heat dissipation device includes a water pump. The pump port of the water pump is connected to the first pipeline and / or the second pipeline, and the water pump is used to drive the circulating flow of the cooling medium.

[0033] In this implementation, by setting the water pump, the flow direction of the cooling medium in the heat dissipation device can also be controlled. The heating elements can be arranged arbitrarily based on the actual usage scenario, and in cooperation with the setting of the flow direction of the cooling medium, the heating elements can obtain better heat dissipation effects.

[0034] In a second aspect, the present application provides another heat dissipation device, including an evaporator, a condenser, and a first pipeline and a second pipeline respectively connected between the evaporator and the condenser; the evaporator includes a housing with a sealed inner cavity. A current-limiting groove is provided in the housing. The current-limiting groove has an opening, and a heating element is fixed in the current-limiting groove. The second pipeline is connected to the inside of the current-limiting groove; the cooling medium in the condenser is transported to the current-limiting groove through the second pipeline. After the cooling medium dissipates heat from the heating element, it flows back to the condenser through the first pipeline for cooling.

[0035] The heat dissipation device provided in the second aspect of the present application also forms a circulation channel through the evaporator, the first pipeline, the condenser, and the second pipeline for the cooling medium to circulate in the circulation channel. Among them, the cooling medium dissipates heat from the heating element in the evaporator, then is cooled in the condenser, and then returns to the evaporator.

[0036] The heat dissipation device of the present application also forms a sealed structure with an opening around the heating element through the setting of the current-limiting groove. When the second pipeline sends the cooling medium towards the current-limiting groove, the cooling medium first fully contacts the heating element for heat dissipation, and then flows into other areas of the inner cavity through the opening, thereby ensuring the heat dissipation effect of the cooling medium on the heating element.

[0037] In a possible implementation, a plurality of heating elements are fixed in the housing, and a current-limiting groove is provided outside each heating element. The number of the corresponding second pipelines is the same as the number of the heating elements, and each second pipeline is connected to the inside of a current-limiting groove.

[0038] In a possible implementation, the housing includes a front cover and a rear cover fixed at intervals, and a current-limiting plate and a current-limiting wall connected between the front cover and the rear cover; the heating element is located between the front cover and the rear cover and is fixed to the front cover or the rear cover. The current-limiting plate is located at the bottom of the heating element, and two current-limiting walls are located on both sides of the heating element. The front cover, the rear cover, the current-limiting plate, and the current-limiting wall jointly enclose to form a current-limiting groove.

[0039] In this implementation, by setting the current-limiting plate and the current-limiting wall to be respectively connected between the front cover and the rear cover, partial areas of the front cover and the rear cover can be utilized to jointly enclose with the current-limiting plate and the current-limiting wall to form a current-limiting groove, so as to form a better wrapping effect on the heating element.

[0040] In a possible implementation, the heating element is fixed to the inner side wall of one of the front cover and the rear cover, and the second pipeline is connected to the inner side wall of the other cover.

[0041] In this implementation, the heating element is fixed to one side of the inner cavity, and the cooling working fluid enters the current-limiting groove from the other side, which can enable the cooling working fluid to fully contact the heating element in the current-limiting groove and ensure the heat dissipation effect of the cooling working fluid on the heating element.

[0042] In a possible implementation, the cooling working fluid in the condenser is transported to the current-limiting groove through the second pipeline under the action of gravity. After the cooling working fluid dissipates heat from the heating element, it flows into the first pipeline through the opening and returns to the condenser against the direction of gravity for cooling.

[0043] In this implementation, the condenser is located above the evaporator along the direction of gravity. When the cooling working fluid is transported to the inner cavity through the second pipeline under the action of gravity, the cooling working fluid can be in a liquid state; while after the cooling working fluid dissipates heat from the heating element, it can be converted into a gaseous state and then flow back into the condenser against the direction of gravity through the first pipeline.

[0044] In a possible implementation, the opening of the current-limiting groove faces upward against the direction of gravity.

[0045] In this implementation, the opening of the current-limiting groove faces upward against the direction of gravity. The cooling working fluid in the current-limiting groove can form an immersion effect on the heating element under the action of gravity. The relatively low-temperature cooling working fluid flowing in from the second pipeline can have more sufficient contact with the heating element, improving the heat dissipation capacity of the heat dissipation device.

[0046] In a possible implementation, the housing further includes a plurality of spaced-apart support columns located in the inner cavity; opposite ends of each support column are respectively fixedly connected to the front cover and the rear cover; the support columns are used to enhance the structural stability of the housing.

[0047] In a possible implementation, the heating element is fixed to the inner side wall of one of the front cover and the rear cover, and the inner side wall of the other cover is provided with a fitting area. The position of the fitting area is at least partially aligned with the heating element. The fitting area is provided with a convex block, and the convex block protrudes towards the heating element and contacts the heating element. The convex block also has pores, and the pores are at least located on the end face where the convex block contacts the heating element.

[0048] In a possible implementation, there is a first distance between any two adjacent support columns. The pores of the convex block are formed by irregular arrangement of a plurality of holes, and the inner diameter size of any hole is smaller than the first distance.

[0049] In a possible implementation, there is a first distance between any two adjacent support columns. The bump includes a plurality of protruding portions arranged at intervals, and the gaps between the plurality of protruding portions form pores. The distance between any two adjacent protruding portions is less than the first distance.

[0050] In a possible implementation, the housing is provided with a first communication hole and a second communication hole. The first pipeline is communicated to the inner cavity through the first communication hole, and the second pipeline is communicated to the inner cavity through the second communication hole. The first communication hole is located above the second communication hole along the direction of gravity.

[0051] In a possible implementation, the first communication hole is located at the top of the housing along the direction of gravity.

[0052] In a possible implementation, the heat dissipation device includes a water pump. The pump port of the water pump is communicated with the first pipeline and / or the second pipeline, and the water pump is used to drive the circulating flow of the cooling working fluid.

[0053] In a possible implementation, the condenser is provided with a liquid inlet communicating with the first pipeline and a liquid outlet communicating with the second pipeline. The liquid inlet is located above the liquid outlet along the direction of gravity.

[0054] In a third aspect, the present application provides another heat dissipation device, including an evaporator, a condenser, and a first pipeline and a second pipeline respectively connected between the evaporator and the condenser; the evaporator includes a housing with a sealed inner cavity. The housing includes a front cover, a middle partition plate, and a rear cover arranged at intervals in sequence. The middle partition plate divides the inner cavity into a front cavity close to the front cover and a rear cavity close to the rear cover. The first pipeline is connected to the front cavity, and the second pipeline is connected to the rear cavity; a current limiting groove is provided in the front cavity, and a heating element is fixed in the current limiting groove. The current limiting groove has an opening, and a partial area of the front cover and a partial area of the middle partition plate are also respectively used to form the current limiting groove; the middle partition plate is provided with a diversion hole communicating between the diversion groove and the rear cavity. The cooling working fluid in the condenser is transported to the rear cavity through the second pipeline, flows into the current limiting groove through the diversion hole, dissipates heat from the heating element, and then returns to the condenser through the first pipeline for cooling.

[0055] The heat dissipation device provided in the third aspect of the present application also forms a circulation channel through the evaporator, the first pipeline, the condenser, and the second pipeline for the cooling working fluid to circulate in the circulation channel. Among them, the cooling working fluid dissipates heat from the heating element in the evaporator, is then cooled in the condenser, and then returns to the evaporator.

[0056] The heat dissipation device of the present application also limits the flow path of the cooling working fluid through the setting of the middle partition plate. When the cooling working fluid enters the front cavity from the rear cavity, because the diversion hole is located between the rear cavity and the current limiting groove, it can ensure that the cooling working fluid directly enters the current limiting groove to dissipate heat from the heating element, so as to ensure the heat dissipation effect of the cooling working fluid on the heating element.

[0057] In a possible implementation, the housing includes a current-limiting plate and a current-limiting wall connected between the front cover and the middle partition; the heating element is fixed to the front cover or the middle partition, the current-limiting plate is located at the bottom of the heating element, and the two current-limiting walls are located on both sides of the heating element. The front cover, the middle partition, the current-limiting plate, and the current-limiting wall jointly enclose a current-limiting groove.

[0058] In a possible implementation, a plurality of heating elements are fixed inside the housing, and a current-limiting groove is provided outside each heating element. The middle partition is provided with at least one drainage hole corresponding to each current-limiting groove.

[0059] In a possible implementation, the cooling working medium in the condenser is transported to the current-limiting groove through the second pipeline under the action of gravity. After the cooling working medium dissipates heat from the heating element, it flows into the first pipeline through the opening and returns to the condenser against the direction of gravity for cooling.

[0060] In a possible implementation, the heating element includes at least a first heating element and a second heating element. The first heating element and the second heating element are fixed at intervals. In the direction perpendicular to the direction in which the first heating element and the second heating element are arranged at intervals, the first heating element and the second heating element form two mutually spaced projection areas on the inner surface of the housing; the second pipeline has a second communication hole communicating with the housing, and the second communication hole and the two projection areas are located on the same inner surface of the housing, and the second communication hole is located between the two projection areas.

[0061] In this implementation, the second pipeline is connected to the rear cavity through the second communication hole, and the second communication hole is located between the projection areas formed by the first heating element and the second heating element. The cooling working medium entering the rear cavity from the second communication hole can flow in two opposite directions, and then enter the current-limiting grooves corresponding to the first heating element and the second heating element respectively through two different drainage holes, thereby respectively forming a heat dissipation effect on the first heating element and the second heating element, ensuring the uniformity of heat dissipation.

[0062] In a possible implementation, the first heating element is located above the second heating element along the direction of gravity. The housing further includes two opposite side plates, and the two opposite side plates are respectively arranged on both sides of the front cover and are respectively connected between the front cover and the rear cover. The number of the second pipelines is two, and each second pipeline is connected to one side plate.

[0063] In a possible implementation, there are a plurality of drainage holes, and the plurality of drainage holes are arranged at intervals along the length direction of the current-limiting plate and / or the current-limiting wall.

[0064] In a possible implementation, the drainage hole is strip-shaped, and the strip-shaped drainage hole extends along the length direction of the current-limiting plate and / or the current-limiting wall.

[0065] In a possible implementation, the drainage holes are strip-shaped. The strip-shaped drainage holes extend along the length direction of the current-limiting wall and the current-limiting wall at the same time, and the strip-shaped drainage holes are connected in sequence.

[0066] In the above various implementations, different structures of the drainage holes can increase their areas, so that more cooling working medium can flow into the current-limiting groove to dissipate heat from the heating element.

[0067] In a possible implementation, the housing further includes a plurality of spaced-apart support columns. The plurality of support columns are located in the inner cavity; opposite ends of each support column are fixedly connected to the front cover and the middle partition respectively; the support columns are used to improve the structural stability of the housing.

[0068] In a possible implementation, the heating element is fixed to the inner side wall of one of the front cover and the middle partition. The inner side wall of the other cover is provided with a fitting area. The position of the fitting area is at least partially aligned with the heating element. The fitting area is provided with a convex block, and the convex block protrudes towards the heating element and contacts the heating element. The convex block also has pores, and the pores are at least located on the end face where the convex block contacts the heating element.

[0069] In a possible implementation, there is a first distance between any two adjacent support columns. The pores of the convex block are formed by irregular arrangement of a plurality of holes, and the inner diameter size of any hole is smaller than the first distance.

[0070] In a possible implementation, there is a first distance between any two adjacent support columns. The convex block includes a plurality of spaced-apart protrusions. The gaps between the plurality of protrusions form pores, and the distance between any two adjacent protrusions is smaller than the first distance.

[0071] In a possible implementation, the housing is provided with a first communication hole and a second communication hole. The first pipeline is communicated to the inner cavity through the first communication hole, and the second pipeline is communicated to the inner cavity through the second communication hole. The first communication hole is located above the second communication hole in the direction of gravity.

[0072] In a possible implementation, the first communication hole is located at the top of the housing in the direction of gravity.

[0073] In a possible implementation, the heat dissipation device includes a water pump. The pump port of the water pump is communicated with the first pipeline and / or the second pipeline. The water pump is used to drive the circulating flow of the cooling working medium.

[0074] In a possible implementation, the condenser is provided with a liquid inlet communicating with the first pipeline and a liquid outlet communicating with the second pipeline. The liquid inlet is located above the liquid outlet in the direction of gravity.

[0075] Fourth aspect, the present application provides another heat dissipation device, including an evaporator, a condenser, a first pipeline and a second pipeline respectively connected between the evaporator and the condenser; the evaporator includes a housing, the housing has a sealed inner cavity, the housing further includes a front cover and a rear cover fixed at intervals, a heating element is fixed on the inner side wall of one of the front cover and the rear cover, a fitting area is provided on the inner side wall of the other cover, the position of the fitting area is at least partially aligned with the heating element, the fitting area is provided with bumps, and the bumps protrude towards the heating element and are in contact with the heating element, the bumps further have pores, and the pores are at least located on the end surface of the bump in contact with the heating element; the cooling working medium in the condenser is transported to the inner cavity through the second pipeline, the cooling working medium flows back to the condenser through the first pipeline for cooling, and part of the cooling working medium dissipates heat from the heating element at the pores of the bump.

[0076] The heat dissipation device provided in the fourth aspect of the present application also forms a circulation channel through the evaporator, the first pipeline, the condenser, and the second pipeline for the cooling working medium to circulate in the circulation channel. Among them, the cooling working medium dissipates heat from the heating element in the evaporator, then is cooled in the condenser, and then returns to the evaporator.

[0077] The heat dissipation device of the present application also promotes the heat dissipation effect of the cooling working medium on the heating element by arranging the bumps on the fitting area, so that the pores of the bumps abut against and contact the heating element, and the cooling working medium can form more nucleation points on the surface of the heating element.

[0078] In a possible implementation, the housing further includes a plurality of spaced support columns located in the inner cavity; opposite ends of each support column are respectively fixedly connected to the front cover and the rear cover; the support columns are used to improve the structural stability of the housing.

[0079] In a possible implementation, there is a first distance between any two adjacent support columns, the pores of the bump are formed by irregular arrangement of a plurality of holes, and the inner diameter of any hole is smaller than the first distance.

[0080] In a possible implementation, there is a first distance between any two adjacent support columns, the bump includes a plurality of spaced protrusions, the gaps between the plurality of protrusions form pores, and the distance between any two adjacent protrusions is smaller than the first distance.

[0081] In a possible implementation, the cooling working medium in the condenser is transported to the inner cavity through the second pipeline under the action of gravity, and after the cooling working medium dissipates heat from the heating element, it flows back to the condenser through the first pipeline against the direction of gravity for cooling.

[0082] In a possible implementation, the housing is provided with a first communication hole and a second communication hole. The first pipeline is communicated to the inner cavity through the first communication hole, and the second pipeline is communicated to the inner cavity through the second communication hole. The first communication hole is located above the second communication hole along the direction of gravity.

[0083] In a possible implementation, the first communication hole is located at the top of the housing along the direction of gravity.

[0084] In a possible implementation, the heat dissipation device includes a water pump. The pump port of the water pump is communicated with the first pipeline and / or the second pipeline, and the water pump is used to drive the circulating flow of the cooling working medium.

[0085] In a possible implementation, the condenser is located above the evaporator, and the condenser is provided with a liquid inlet communicating with the first pipeline and a liquid outlet communicating with the second pipeline. The liquid inlet is located above the liquid outlet along the direction of gravity.

[0086] In a fifth aspect, the present application provides a power converter, including a power semiconductor device and any one of the heat dissipation devices in the first to fourth aspects above. The power semiconductor device is fixed in the inner cavity of the heat dissipation device as a heat generating element, and the heat dissipation device is used to dissipate heat from the power semiconductor device.

[0087] It can be understood that for the power converter provided by the present application, its power conversion function is realized through the power semiconductor device. And the power semiconductor device, as a heat generating element, cooperates with the heat dissipation devices in the first to fourth aspects of the present application above to improve the heat dissipation effect of the power semiconductor device, thereby ensuring the reliable operation of the power converter of the present application. Description of the Drawings

[0088] Figure 1 It is a schematic diagram of the frame structure of an inverter provided by an embodiment of the present application;

[0089] Figure 2a It is a schematic diagram of the structure of a heat dissipation device provided by an embodiment of the present application;

[0090] Figure 2b It is a schematic diagram of the structure of another implementation of a heat dissipation device provided by an embodiment of the present application;

[0091] Figure 2c It is a schematic diagram of the structure of yet another implementation of a heat dissipation device provided by an embodiment of the present application;

[0092] Figure 3 It is a schematic diagram of the internal structure of the housing in a heat dissipation device provided by an embodiment of the present application;

[0093] Figure 4 A schematic diagram of the structure of a heat dissipation device in the prior art;

[0094] Figure 5 It is a schematic structural diagram of another embodiment of a heat dissipation device provided by an embodiment of the present application;

[0095] Figure 6 It is a schematic structural diagram of the front cover in a heat dissipation device provided by an embodiment of the present application;

[0096] Figure 7 It is a schematic cross-sectional structural diagram of a heat dissipation device provided by an embodiment of the present application;

[0097] Figure 8a It is a schematic diagram of the pore structure of the front cover in a heat dissipation device provided by an embodiment of the present application;

[0098] Figure 8b It is another schematic diagram of the pore structure of the front cover in a heat dissipation device provided by an embodiment of the present application;

[0099] Figure 8c It is yet another schematic diagram of the pore structure of the front cover in a heat dissipation device provided by an embodiment of the present application;

[0100] Figure 9 It is a schematic structural diagram of another heat dissipation device provided by an embodiment of the present application;

[0101] Figure 10 It is a schematic cross-sectional structural diagram of another heat dissipation device provided by an embodiment of the present application;

[0102] Figure 11 It is a schematic structural diagram of yet another heat dissipation device provided by an embodiment of the present application;

[0103] Figure 12 It is a schematic cross-sectional structural diagram of yet another heat dissipation device provided by an embodiment of the present application;

[0104] Figure 13 It is a schematic structural diagram of the middle partition in yet another heat dissipation device provided by an embodiment of the present application;

[0105] Figure 14 It is a schematic structural diagram of the other side of the middle partition in yet another heat dissipation device provided by an embodiment of the present application;

[0106] Figure 15a It is a partial schematic structural diagram of the current-limiting groove in a heat dissipation device provided by an embodiment of the present application;

[0107] Figure 15b It is another partial schematic structural diagram of the current-limiting groove in a heat dissipation device provided by an embodiment of the present application;

[0108] Figure 16 It is a schematic structural diagram of yet another heat dissipation device provided by an embodiment of the present application;

[0109] Figure 17 It is a schematic front cover structure diagram of another heat dissipation device provided by an embodiment of the present application;

[0110] Figure 18 It is a schematic cross-sectional structure diagram of another heat dissipation device provided by an embodiment of the present application;

[0111] Figure 19a It is a schematic pore structure diagram of the front cover in another heat dissipation device provided by an embodiment of the present application;

[0112] Figure 19b It is another schematic pore structure diagram of the front cover in another heat dissipation device provided by an embodiment of the present application;

[0113] Figure 19c It is yet another schematic pore structure diagram of the front cover in another heat dissipation device provided by an embodiment of the present application. Detailed implementation manners

[0114] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0115] The power converter provided by the present application can be devices such as an inverter, a motor driver, and an uninterruptible power supply. A power semiconductor device is provided in the power converter, which can be used as a controllable switch in the power converter to achieve the function of power conversion. Components such as capacitors, inductors, or resistors can also be provided in the power converter to cooperate with the power semiconductor device to form an inverter circuit or a boost circuit.

[0116] For the convenience of clearly showing the characteristics of the power converter of the present application, in the subsequent embodiments, an inverter is taken as an example to elaborate on the power converter and the inverter circuit it includes. It can be understood that similar power converters can also be used as devices such as motor drivers and uninterruptible power supplies.

[0117] Figure 1 It schematically shows a frame structure diagram of an inverter 200 provided by the present application.

[0118] In Figure 1In the schematic diagram, the inverter circuit of the inverter 200 includes two input terminals 204 and two output terminals 205. Between the input terminal 204 and the output terminal 205, there are four power semiconductor devices 201, a controller 203, and a capacitor 202. The controller 203 is used to control the conduction and turn-off of each power semiconductor device 201. The four power semiconductor devices 201 are respectively defined as switches Q1 to Q4, forming two bridge arms, and each bridge arm includes two power semiconductor devices 201 connected in series between the positive and negative poles of the inverter circuit. The capacitor 202 is connected between the positive and negative poles of the input terminal 204 and is used to filter the voltage and current in the input terminal 204 of the inverter circuit.

[0119] In Figure 1 In the shown inverter circuit, through the control of the controller 203, the four power semiconductor devices 201 are also used as controllable switches, and by controlling the conduction and turn-off states of the four power semiconductor devices 201 in the two bridge arms, two different conduction paths are formed.

[0120] Specifically, the controller 203 has four control ports A, B, C, and D, which respectively correspond to controlling the conduction and turn-off of the four power semiconductor devices 201, Q1, Q2, Q3, and Q4. When the switches Q1 and Q4 are in the conduction state, Q2 and Q3 are in the turn-off state. At this time, the positive and negative poles in the inverter circuit are in positive-phase transmission; when the switches Q2 and Q3 are in the conduction state, the switches Q1 and Q4 are in the turn-off state, and the positive and negative poles in the inverter circuit become in reverse-phase transmission. The positive and negative poles of the voltage obtained at the output terminal 205 are reversed in the two states.

[0121] Thus, Figure 1 The shown inverter circuit realizes the inverter function. It can realize the conversion of DC to AC, or the conversion of AC to DC, and realize the power conversion function. It can be understood that in some embodiments, when the alternating current is three-phase alternating current, six power semiconductor devices 201 can be set, and every two power semiconductor devices 201 are used to realize the power conversion function of one path of alternating current, thereby forming the power conversion of three-phase alternating current.

[0122] The power semiconductor device 201 is usually used for power conversion of high voltage and high current. During its long-term operation, it will generate a large amount of heat. Therefore, the inverter 200 is also provided with a heat dissipation device for dissipating heat from the power semiconductor device 201 to ensure its normal operation.

[0123] Specifically, please refer to Figure 2a the structural schematic diagram of a heat dissipation device 100 provided by the present application shown.

[0124] In Figure 2aIn the illustrated embodiment, the heat dissipation device 100 includes a first pipeline 110, a second pipeline 120, an evaporator 130, and a condenser 140. The first pipeline 110 is connected between the evaporator 130 and the condenser 140, and the second pipeline 120 is also connected between the evaporator 130 and the condenser 140, and the first pipeline 110 and the second pipeline 120 are independent of each other. Thus, the heat dissipation device 100 can form a circulation path of "evaporator 130 - first pipeline 110 - condenser 140 - second pipeline 120 - evaporator 130".

[0125] A cooling working fluid is injected into the heat dissipation device 100, and the cooling working fluid can circulate in this circulation path. Among them, the evaporator 130 includes a housing 150, and a heating element 201 is fixed in the housing 150. The cooling working fluid is used to form a heat exchange with the heating element 201 in the housing 150. After the temperature of the cooling working fluid rises, it can flow from the first pipeline 110 into the condenser 140. The condenser 140 is used to cool down the cooling working fluid, and the cooled cooling working fluid flows back into the evaporator 130 through the second pipeline 120 to form a heat exchange with the heating element 201 again. Circulating in this way, the heat dissipation effect of the heat dissipation device 100 of the present application on the heating element 201 is formed.

[0126] It can be understood that in this embodiment, the heating element 201 can correspond to the power semiconductor device 201 in the above inverter 200. And in Figure 2a the schematic illustration, the number of power semiconductor devices 201 is six, and the inverter 200 can be used for power conversion of three-phase alternating current. The temperature of the power semiconductor device 201 is relatively high during operation. For the cooling working fluid in the heat dissipation device 100 of the present application, it can be water or coolant. After the cooling working fluid forms a heat exchange with the power semiconductor 201, it can evaporate and vaporize, and form a gas-liquid two-phase mixture state at the top of the housing 150. And in some other embodiments, the cooling working fluid in the heat dissipation device 100 can also be in a pure gaseous or pure liquid state, which does not affect the function realization of the heat dissipation device 100.

[0127] Please refer to Figure 3 the specific structure inside the illustrated housing 150.

[0128] In the heat dissipation device 100 provided in this embodiment, the housing 150 has a sealed inner cavity 151, and the evaporator 130 further includes a partition 152. The partition 152 is located in the inner cavity 151 and is used to divide the inner cavity 151 into a first sub-cavity 1511 and a second sub-cavity 1512. In Figure 2a and Figure 3In the schematic diagram, the first sub-chamber 1511 is located above the second sub-chamber 1512 along the direction of gravity. At the same time, the housing 150 is set to be a cuboid, and the partition 152 is arranged horizontally, so that the first sub-chamber 1511 and the second sub-chamber 1512 are also respectively formed into rectangular cavities. In other embodiments, the partition 152 can also be inclined and fixed in the inner cavity 151, so that the first sub-chamber 1511 and the second sub-chamber 1512 are respectively formed into right trapezoidal cavities, which will not affect the function realization of the heat dissipation device 100 of the present application.

[0129] Please continue to refer to Figure 3 , in this embodiment, multiple power semiconductor devices 201 are all fixed in the first sub-chamber 1511. The first pipeline 110 communicates with the first sub-chamber 1511, and the second pipeline 120 communicates with the second sub-chamber 1512. A diversion hole 1521 is also provided in the partition 152, and the diversion hole 1521 is used to communicate the first sub-chamber 1511 and the second sub-chamber 1512. Based on the above description of the circulation path of the cooling working medium, the cooling working medium cooled by the condenser 140 first flows into the lower second sub-chamber 1512 through the second pipeline 120. Then, the cooling working medium can pass through the diversion hole 1521 and then enter the first sub-chamber 1511 to form a heat exchange with the power semiconductor device 201.

[0130] For the heat dissipation device 100 of this embodiment, the diversion holes 1521 in the partition 152 need to be set corresponding to the positions of the power semiconductor devices 201, and the diversion holes 1521 are located below the power semiconductor devices 201, and at least part of the diversion holes 1521 are directly opposite to the power semiconductor devices 201 located in the first sub-chamber 1511. Among them, the so-called "directly opposite" refers to the flow direction of the cooling working medium when the cooling working medium flows from the diversion hole 1521 to the first sub-chamber 1511 for dissipating heat from the power semiconductor device 201 corresponding to the diversion hole 1521. In the illustrated embodiment, the diversion holes 1521 can also be set to be completely directly opposite to the power semiconductor devices 201, that is, the diversion holes 1521 are located directly below the power semiconductor devices 201.

[0131] Thus, in this embodiment, the number of the diversion holes 1521 is three, and one diversion hole 1521 is provided below each power semiconductor device 201. The cooling working medium with a relatively low temperature flowing from the second sub-chamber 1512 into the first sub-chamber 1511 can reach the power semiconductor device 201 through a relatively short flow path and form a heat exchange with the power semiconductor device 201.

[0132] It can be understood that at the position where the power semiconductor device 201 is not provided, the cooling working fluid cannot enter the first sub-chamber 1511 due to the blocking effect of the partition plate 152. The cooling working fluid only enters the first sub-chamber 1511 through the diversion holes 1521. The flow path of the cooling working fluid is relatively short during the process of reaching the power semiconductor 201, and the heat exchange it undergoes in the first sub-chamber 1511 with a relatively high temperature is also relatively small. Thus, it is ensured that when the cooling working fluid exchanges heat with the power semiconductor device 201, its temperature is relatively low, thereby improving the heat dissipation effect of the heat dissipation device 100 of the present application on the power semiconductor device 201.

[0133] Please refer to Figure 4 the structure of a heat dissipation device 100a in the prior art shown in the figure.

[0134] In Figure 4 in the prior art heat dissipation device 100a shown in the figure, the flow path of the cooling working fluid in the inner cavity 151a is not restricted. After the cooling working fluid enters the inner cavity 151a, its flow path to reach the power semiconductor device 201 is relatively long. This causes the cooling working fluid to have undergone heat exchange in the inner cavity 151a for a relatively long time when it reaches the power semiconductor device 201, and the temperature of the cooling working fluid flowing to the power semiconductor device 201 is relatively high. Therefore, the heat dissipation efficiency of the prior art heat dissipation device 100a for the power semiconductor device 201 is also relatively reduced, and its heat dissipation effect is relatively limited.

[0135] Please refer to Figure 2b and Figure 2c the schematic diagrams of two other structures of the heat dissipation device 100 provided by the present application shown in the figure.

[0136] In Figure 2b the schematic diagram, the first sub-chamber 1511 is located below the second sub-chamber 1512 along the direction of gravity, and the diversion holes 1521 in the partition plate 152 are located above each power semiconductor device 201. The diversion holes 1521 are at least partially arranged facing the power semiconductor device 201 in the first sub-chamber 1511. At this time, the second pipeline 120 feeds the cooling working fluid from above the inner cavity 151 (the second sub-chamber 1512), and the cooling working fluid flows from the diversion holes 1521 to the power semiconductor device 201 under the action of gravity. Due to the effect of the partition plate 152, when the cooling working fluid flows from the second sub-chamber 1512 to the power semiconductor device 201, its flow path is also relatively short, and the same beneficial effects similar to those of the Figure 2a heat dissipation device 100 shown in the figure can be achieved.

[0137] And in Figure 2cIn the schematic diagram, the number of the partition plates 152 is two. The two partition plates 152 respectively form a second sub-chamber 1512 on the opposite sides of the inner cavity 151, and form a first sub-chamber 1511 in the middle of the inner cavity 151. That is, in this embodiment, the two second sub-chambers 1512 are respectively located on the opposite sides of the first sub-chamber 1511. At this time, the diversion holes 1521 in the partition plates 152 are at least partially directly opposite to the power semiconductor device 201 from the side. The second pipeline 120 feeds the cooling working medium into the second sub-chambers 1512 on both sides of the inner cavity 151 respectively. Under the action of pressure, the cooling working medium flows from the diversion holes 1521 to the power semiconductor device 201. Due to the function of the partition plates 152, when the cooling working medium flows from the second sub-chamber 1512 to the power semiconductor device 201, its flow path is also relatively short, and the beneficial effects similar to those of the heat dissipation device 100 shown in Figure 2a and Figure 2b can be achieved.

[0138] Therefore, in the process of separating the inner cavity 151 into the first sub-chamber 1511 and the second sub-chamber 1512 by the partition plates 152 in the heat dissipation device 100 provided in this embodiment, the relative positions of the first sub-chamber 1511 and the second sub-chamber 1512 are not strictly limited. As long as it is ensured that the diversion holes 1521 in the partition plates 152 are at least partially directly opposite to the power semiconductor device 201, it can be ensured that the cooling working medium reaches the power semiconductor device 201 through a relatively short flow path, thereby improving the heat dissipation effect of the heat dissipation device 100.

[0139] For an embodiment, please refer to Figure 5 , and multiple power semiconductor devices 201 can be arranged in an array in the inner cavity 151. In this embodiment, the multiple power semiconductor devices 201 can include a first power semiconductor device 201a and a second power semiconductor device 201b. Among them, the first power semiconductor device 201a is located above the second power semiconductor device 201b along the gravity direction. Further, the housing 150 is also provided with a current limiting plate 153. The current limiting plate 153 is located between the first power semiconductor device 201a and the second power semiconductor device 201b and is used for guiding the cooling working medium flowing from the second power semiconductor device 201b to the first power semiconductor device 201a.

[0140] It can be understood that corresponding to the embodiments of Figure 2b or Figure 2c , when the flow direction of the cooling working medium is the same as Figure 5When the flow direction of the cooling working fluid is different, the second power semiconductor device 201b can be located between the first power semiconductor device 201 and the partition plate 152. Cooperating with the current-limiting plate 153 located between the first power semiconductor device 201a and the second power semiconductor device 201b, it can also divert the cooling working fluid flowing from the second power semiconductor device 201b to the first power semiconductor device 201a.

[0141] Specifically, please continue to refer to Figure 5 , when the cooling working fluid enters the first sub-chamber 1511 from the lower second sub-chamber 1512, it will first contact the relatively lower second power semiconductor device 201b, and after heat exchange with the second power semiconductor device 201b, it will flow upward against the direction of gravity to the first power semiconductor device 201a to form heat exchange with the first power semiconductor device 201a. Thus, during the process of the temperature rise of the cooling working fluid, it will also flow towards the top of the inner cavity 151. Correspondingly, some liquid cooling working fluid may generate bubbles when heat exchanging with the power semiconductor 201. The bubbles will also flow towards the top of the inner cavity 151.

[0142] For the heat dissipation device 100 in this embodiment, if bubbles are generated when the cooling working fluid exchanges heat with the second power semiconductor device 201b, the bubbles will continue to flow upward along the flow direction of the cooling working fluid and may contact the first power semiconductor device 201a. The more bubbles that contact the first power semiconductor device 201a, the less cooling working fluid that forms heat exchange with the first power semiconductor device 201a. That is, the more bubbles flowing towards the first power semiconductor device 201a, the worse the heat dissipation effect of the cooling working fluid on the first power semiconductor device 201a.

[0143] And in Figure 5 's schematic illustration, the current-limiting plate 153 provided in this embodiment is also provided with through holes 1531. The number of the holes 1531 is multiple, and the multiple holes 1531 are arranged at intervals on the current-limiting plate 153. The width of the holes 1531 is relatively narrow and can be used to block the bubbles flowing from the second power semiconductor device 201b to the first power semiconductor device 201a. It can be understood that when the volume of the bubbles is relatively large, because they cannot pass through the relatively narrow holes 1531, the bubbles may burst, or flow along the direction of the current-limiting plate 153 and cross from the side of the current-limiting plate 153 and continue to flow upward along the flow direction of the cooling working fluid. And the liquid cooling working fluid can pass through the holes 1531 and flow to the first power semiconductor device 201a located above the current-limiting plate 153.

[0144] Thus, under the action of the current-limiting plate 153, the first power semiconductor device 201a avoids excessive contact with the bubbles and instead comes into contact with the liquid cooling working medium, thereby improving the heat dissipation effect of the heat dissipation device 100 of the present application on the first power semiconductor device 201a.

[0145] It can be understood that corresponding to the Figure 2b embodiment, the current-limiting plate 153 is located between the first power semiconductor device 201a and the second power semiconductor device 201b. Because Figure 2b in the first power semiconductor device 201a is located vertically below the second power semiconductor device 201b, the current-limiting plate 153 is used to divert the cooling working medium flowing along the direction of gravity.

[0146] In Figure 2b the embodiment, the current-limiting plate 153 can also be provided with a hole slot 1531 for blocking bubbles ( Figure 2b not shown). Because when the cooling working medium exchanges heat with the second power semiconductor device 201b above, bubbles may be formed, and the bubbles may continue to flow downward to the first power semiconductor device 201a along with the cooling working medium; when the cooling working medium exchanges heat with the first power semiconductor device 201a below, bubbles may also be formed, and because the bubbles are lighter in weight, they will flow upward against the direction of gravity towards the second power semiconductor 201b above. Thus, the current-limiting plate 153 can form an effect of blocking bubbles in two opposite directions, thereby respectively ensuring reliable heat dissipation effects for the first power semiconductor device 201a and the second power semiconductor device 201b.

[0147] Corresponding to the Figure 2c embodiment, the current-limiting plate 153 can be located horizontally between the first power semiconductor device 201a and the second power semiconductor device 201b. Among the three power semiconductor devices 201 at the same horizontal height, the middle power semiconductor device 201 is formed as the first power semiconductor device 201a, and the two power semiconductor devices 201 on both sides are respectively formed as the second power semiconductor device 201b. The cooling working medium flows from both sides of the inner cavity 151 towards the middle, and the current-limiting plate 153 can divert the cooling working medium flowing from both sides to the first power semiconductor device 201a. Further, when the current-limiting plate 153 is provided with a hole slot 1531 ( Figure 2c not shown), it can also play an effect of blocking bubbles from flowing to the first power semiconductor device 201a.

[0148] As mentioned above, under the blocking effect of the flow limiting plate 153, the bubbles will pass through from the side of the flow limiting plate 153 and continue to flow with the cooling working fluid. In one embodiment, the housing 150 is further provided with a flow limiting wall 154. The flow limiting wall 154 is located on the side of the first power semiconductor device 201a and is used to block the contact between the bubbles and the side of the first power semiconductor device 201a, further improving the heat dissipation effect of the first power semiconductor device 201a.

[0149] Specifically, as Figure 5 shown, there can be one flow limiting wall 154. This one flow limiting wall 154 is located on one side of the first power semiconductor device 201a, and this one flow limiting wall 154 is fixedly connected to the flow limiting plate 153 and is used to block the contact between the bubbles on one side and the side of the first power semiconductor device 201a. When the number of the flow limiting walls 154 is one, this one flow limiting wall 154 can also be located between two first power semiconductor devices 201a. Since the power semiconductor devices 201 are arranged in an array, when two first power semiconductor devices 201a are arranged side by side, there will also be two second power semiconductor devices 201b arranged side by side below them. The two second power semiconductor devices 201b below work together, and the number of bubbles generated by them may be more. Therefore, arranging the flow limiting wall 154 between two first power semiconductor devices 201a can form a better effect of blocking bubbles.

[0150] In another embodiment, the number of the flow limiting walls 154 can also be two. The two flow limiting walls 154 are respectively arranged on the opposite sides of the first power semiconductor device 201a, and the two flow limiting walls 154 are respectively fixedly connected to the opposite ends of the flow limiting plate 153. At this time, the two flow limiting walls 154 can respectively form an effect of blocking bubbles on the opposite sides of the first power semiconductor device 201a to ensure that the first power semiconductor device 201a contacts and exchanges heat with the liquid cooling working fluid more, improving the heat dissipation effect of the heat dissipation device 100 of the present application.

[0151] In one embodiment, a slit structure (not shown in the figure) can also be provided on the flow limiting wall 154. This slit structure can, on the one hand, form a blocking effect on the bubbles, and on the other hand, allow the liquid cooling working fluid to pass through, thereby forming a better heat dissipation effect on the first power semiconductor device 201a.

[0152] In Figure 2b the shown structure, since the first power semiconductor device 201a is located below the second power semiconductor device 201b along the gravity direction, the flow limiting wall 154 also extends downward along the gravity direction; while in Figure 2c the shown structure, the flow limiting wall 154 extends toward the first power semiconductor device 201a along the horizontal direction. And since flow limiting plates 153 are provided on both sides of the first power semiconductor device 201a, therefore, inFigure 2c In the schematic illustration, the current-limiting wall 154 may extend only from the current-limiting plate 153 on one side to the first power semiconductor device 201a.

[0153] Please refer back to Figure 3 the schematic illustration. The housing 150 includes a front cover 155, a rear cover 156, and side plates 157. The front cover 155 and the rear cover 156 are fixedly spaced apart from each other, and the side plates 157 are fixedly connected between the front cover 155 and the rear cover 156. The number of side plates 157 is two, and the two side plates 157 are arranged on opposite sides of the housing 150. In one embodiment, the current-limiting plate 153 is fixedly connected to both the front cover 155 and the rear cover 156 at the same time. Thus, the current-limiting plate 153 has a better effect of blocking air bubbles, preventing air bubbles from passing through the gaps between the current-limiting plate 153 and the front cover 155 or between the current-limiting plate 153 and the rear cover 156, and coming into contact with the first power semiconductor device 201a.

[0154] In other embodiments, the current-limiting wall 154 may also be fixedly connected to both the front cover 155 and the rear cover 156 at the same time. Its function is similar to that of the current-limiting plate 153, and it can also prevent air bubbles from passing through the gaps, thereby ensuring the heat dissipation effect of the first power semiconductor device 201a.

[0155] In one embodiment, the diversion hole 1521 may further include a plurality of diversion sub-holes 1521a (see Figure 5 ). Or it can be described that the diversion hole 1521 is formed by a plurality of mutually spaced diversion sub-holes 1521a. The arrangement of the plurality of diversion sub-holes 1521a can enable the cooling working medium to flow into the first sub-chamber 1511 relatively evenly and form a better heat dissipation effect on the power semiconductor device 201.

[0156] On the other hand, air bubbles may also be generated during the flow of the cooling working medium. Or, when the cooling working medium flowing out of the condenser 140 is also in a gas-liquid two-phase state, the cooling working medium flowing into the second sub-chamber 1512 may also contain air bubbles. The arrangement of the plurality of diversion sub-holes 1521a can also have a blocking effect on the air bubbles in the second sub-chamber 1512, preventing the air bubbles from passing through the diversion hole 1521 into the first sub-chamber 1511 and coming into contact with the second power semiconductor device 201b, which affects the heat dissipation effect of the heat dissipation device 100 on the second power semiconductor device 201b.

[0157] In Figure 5In the schematic illustration, the housing 150 further includes a plurality of spaced-apart support columns 158. The plurality of support columns 158 are located in the inner cavity 151. Opposite ends of each support column 158 are fixedly connected to the front cover 155 and the rear cover 156 respectively, thereby enhancing the overall structural stability of the housing 150. During the operation of the heat dissipation device 100 of the present application, the inner cavity 151 is always in a high-temperature state. The long-term high-temperature environment may cause the housing 150 to deform. The arrangement of the support columns 158 can respectively hold the front cover 155 and the rear cover 156, thereby preventing the housing 150 from deforming. The support columns 158 can be integrally formed with the front cover 155 or the rear cover 156, or the support columns 158 can be fixedly connected to the front cover 155 or the rear cover 156 by welding or other means.

[0158] On the other hand, the support columns 158 are arranged in the inner cavity 151 and can also form a certain guiding effect on the cooling working fluid. Specifically, when the cooling working fluid flows through each support column 158, an effect of guiding and diverting is formed, which can make the flow of the cooling working fluid in the inner cavity 151 more uniform and more sufficient, thereby making the temperature distribution in the inner cavity 151 more balanced, and thus improving the heat dissipation effect of the heat dissipation device 100 of the present application.

[0159] In one embodiment, the housing 150 is provided with a first communication hole 1513 and a second communication hole 1514 (see Figure 3 ). The first pipeline 110 is communicated to the inner cavity 151 through the first communication hole 1513, and the second pipeline 120 is communicated to the inner cavity 151 through the second communication hole 1514. In one embodiment, the first communication hole 1513 is located above the second communication hole 1514 along the gravity direction. For example, in Figure 5 the heat dissipation device 100 shown, the first communication hole 1513 is located at the first sub-cavity 1511, and the second communication hole 1514 is located at the second sub-cavity 1512. The first sub-cavity 1511 is located above the second sub-cavity 1512 along the gravity direction, so that the first communication hole 1513 is also located above the second communication hole 1514 along the gravity direction.

[0160] Since the cooling working fluid with a higher temperature in the inner cavity 151 will flow upward and the bubbles will also flow upward, high-temperature gaseous cooling working fluid accumulates more at the top of the inner cavity 151. When the first communication hole 1513 is located at a relatively upper position in the inner cavity 151, it can enable the cooling working fluid with a relatively higher temperature (in a gaseous or gas-liquid mixed state) to flow to the condenser 140 through the first pipeline 110, that is, the condenser 140 can cool the cooling working fluid with a relatively higher temperature. And the second communication hole 1514 is located at a relatively lower position in the inner cavity 151, which can enable the cooling working fluid with a relatively lower temperature to enter the inner cavity 151 from a relatively lower position and flow upward in the inner cavity 151 to achieve a better cooling effect.

[0161] In one embodiment, the first communication hole 1513 is also located at the top of the housing 150 along the direction of gravity. In one embodiment, the number of the first communication holes 1513 can be two, and correspondingly, the number of the first pipelines 110 is also two. The two first communication holes 1513 are arranged at intervals to relatively evenly send the cooling working medium back to the condenser 140 from the top of the inner cavity 151.

[0162] In one embodiment, the number of the second communication holes 1514 is also two. The two second communication holes 1514 are respectively arranged on both sides of the housing 150, that is, the two second pipelines 120 are respectively communicated to the two side plates 157 of the housing 150. The two second pipelines 120 can send the relatively low-temperature cooling working medium from the opposite sides of the second sub-cavity 1512, which is beneficial to ensuring the temperature balance of the cooling working medium in the inner cavity 151.

[0163] For an embodiment, please refer to Figure 2a , the heat dissipation device 100 of the present application is further provided with a water pump 160. The pump port of the water pump 160 is communicated with the circulation path of the heat dissipation device 100 and can be used to provide power for the circulating flow of the cooling working medium. In Figure 2a the schematic diagram, the pump port of the water pump 160 is communicated with the first pipeline 110. In some other embodiments, the pump port of the water pump 160 can also be communicated with the second pipeline 120. Further, in some embodiments, the number of the water pumps 160 can be multiple. The pump ports of some water pumps 160 are communicated with the first pipeline 110, and the pump ports of the other water pumps 160 are communicated with the second pipeline 120. The multiple water pumps 160 cooperate to jointly provide power for the circulating flow of the cooling working medium. It can be understood that, in some embodiments, the water pump 160 can also be arranged inside the condenser 140 or the evaporator 130.

[0164] While in Figure 5 the schematic diagram, by arranging the condenser 140 above the evaporator 130 along the direction of gravity, the structure of the water pump 160 can be omitted. Specifically, in this embodiment, the cooling working medium in the condenser 140 can be transported to the second sub-cavity 1512 through the second pipeline 120 under the action of gravity. The cooling working medium flows into the first sub-cavity 1511 against the direction of gravity through the diversion hole 1521, dissipates heat from the power semiconductor device 201, and then flows back to the condenser 140 against the direction of gravity through the first pipeline 110 for cooling. At this time, the condenser 140 can further include a liquid inlet 141 and a liquid outlet 142. The liquid inlet 141 is communicated with the first pipeline 110, and the liquid outlet 142 is communicated with the second pipeline 120. The liquid inlet 141 needs to be located above the liquid outlet 142 along the direction of gravity.

[0165] During the operation of the heat dissipation device 100 of the present application, the cooling working fluid with a relatively high temperature has a lower density and can rise upward against the direction of gravity and enter the first pipeline 110. Then, it enters the condenser 140 above from the liquid inlet 141 through the first pipeline 110 for cooling. The cooled cooling working fluid has a higher density and enters the second pipeline 120 through the liquid outlet 142 under the action of gravity, and further returns to the inner cavity 151 through the second pipeline 120. The heat dissipation device 100 in this embodiment can be formed as a gravity heat pipe, and the cooling working fluid can automatically form a circulating flow effect. Moreover, since the structure of the water pump 160 is omitted, the overall volume of the heat dissipation device 100 is reduced, and the energy consumption is further reduced.

[0166] For an embodiment, please refer to Figure 6 For the heat dissipation device 100 of the present application, each power semiconductor device 201 can be fixed on the inner side wall of the rear cover 156. Correspondingly, a fitting area can be provided on the inner side wall of the front cover 155. The position of the fitting area is at least partially aligned with the position of the power semiconductor device 201. The fitting area is also provided with a protrusion 1551, and the protrusion 1551 protrudes towards the power semiconductor device 201. Please refer to Figure 7 synchronously. After the front cover 155 is assembled on the housing 150, the end face of the protrusion 1551 of the front cover 155 facing the power semiconductor device 201 abuts against and contacts the power semiconductor device 201. In this embodiment, the protrusion 1551 is also provided with pores 1552 (such as Figure 8a ), and the pores 1552 are at least located on the end face of the protrusion 1551 facing the power semiconductor device 201. Thus, the pores 1552 of the protrusion 1551 form an abutting and contacting effect with the power semiconductor device 201.

[0167] In Figure 8a the schematic illustration, the pores 1552 can be a layer structure with a pore shape, or it can be described that the pores 1552 are formed by a plurality of holes 1553a with different sizes and irregular arrangements. When the pores 1552 of the protrusion 1551 are attached to the surface of the power semiconductor device 201, a large number of nucleation points can be formed on the surface of the power semiconductor device 201. A nucleation point is also called nucleation, which refers to the incubation center when the cooling working fluid undergoes a phase change. In the embodiment of the present application, it can be understood as the "vaporization center" when the liquid cooling working fluid undergoes vaporization. The cooling working fluid vaporizes at the nucleation point, absorbs more heat, and forms a better heat exchange effect, thereby improving the heat dissipation effect of the cooling working fluid on the power semiconductor device 201.

[0168] In one embodiment, the bonding area can also be completely aligned with the power semiconductor device 201, that is, the shape, size, and position of the bonding area are set corresponding to the power semiconductor device 201, so that the bump 1551 can be in complete contact with the surface of the power semiconductor device 201. At this time, the number of nucleation points formed on the surface of the power semiconductor device 201 is larger, and the heat dissipation effect of the cooling working fluid on the power semiconductor device 201 is better.

[0169] In one embodiment, the pore 1552 can also be set as a raised portion having a dense protrusion shape. As Figure 8b shown, the raised portion can be set as a structure of dense struts 1553b, or as Figure 8c shown, the raised portion is set as a structure of dense dot matrix 1553c. When multiple raised portions are in contact with the surface of the power semiconductor device 201, a structure of multiple nucleation points can also be formed on the surface of the power semiconductor device 201.

[0170] In one embodiment, when the support columns 158 are further provided in the inner cavity 151, the multiple support columns 158 are arranged at intervals. And there is a first distance between any two adjacent support columns 158. This first distance can be understood as the closest interval distance between two adjacent support columns 158.

[0171] At this time, when the pore 1552 of the bump 1551 is as Figure 8a shown and is formed by irregular arrangement of multiple holes 1553a, the inner diameter dimension of any hole 1553a is smaller than the first distance between the two support columns 158. Such a setting can ensure that the pore 1552 is denser than the arrangement of the support columns 158, so as to ensure that the position of the nucleation point is at the pore 1552 of the bump 1551.

[0172] And when the pore 1552 of the bump 1551 is as Figure 8b or Figure 8c shown and is formed by the gap between multiple spaced-apart raised portions (struts 1553b or dot matrix 1553c), the distance between any two adjacent raised portions is also smaller than the first distance, which can also ensure that the arrangement of the pore 1552 is denser and ensure that the position of the nucleation point is at the pore 1552 of the bump 1551, thereby ensuring the heat dissipation effect of the cooling working fluid on the power semiconductor device 201.

[0173] It should be noted that in Figure 6 and Figure 7In the schematic illustration, the power semiconductor device 201 is fixed to the rear cover 156, and a bump 1551 protruding from the self-adhesive area is formed on the front cover 155. In some other embodiments, the power semiconductor device 201 can also be fixed to the front cover 155, and an adhesive area at least partially aligned with the power semiconductor device 201 is provided on the rear cover 156. Then, a structure with a protruding bump 1551 is provided on the adhesive area, and pores 1552 are provided on the bump 1551. Such a setting method can also make the surface of the bump 1551 with pores 1552 contact the power semiconductor device 201, and form multiple nucleation points on the power semiconductor device 201, improving the heat dissipation effect of the cooling working medium on the power semiconductor device 201.

[0174] Please refer to Figure 9 the structure of another heat dissipation device 300 provided by the present application shown in the figure. The heat dissipation device 300 includes multiple elements identical to those of the heat dissipation device 100. Therefore, similar element numbers are the same, except that the reference numerals start with "3" instead of "1".

[0175] In Figure 9 the illustrated embodiment, the heat dissipation device 300 also includes a first pipeline 310, a second pipeline 320, an evaporator 330, and a condenser 340. The first pipeline 310 is connected between the evaporator 330 and the condenser 340, and the second pipeline 320 is also connected between the evaporator 330 and the condenser 340. A cooling working medium is injected into the heat dissipation device 300, thereby forming a cooling working medium circulation path of "evaporator 330 - first pipeline 310 - condenser 340 - second pipeline 320 - evaporator 330".

[0176] The evaporator 330 includes a housing 350, and a heating element 201 is fixed inside the housing 350. After the cooling working medium forms a heat exchange with the heating element 201 inside the housing 350, it flows from the first pipeline 310 into the condenser 340. After the condenser 340 cools down the cooling working medium, the cooling working medium flows back into the evaporator 330 through the second pipeline 320 to form a heat exchange with the heating element 201 again.

[0177] In this embodiment, the heating element 201 can also correspond to the power semiconductor device 201 in the above-mentioned inverter 200. And in Figure 9 the schematic illustration, the number of power semiconductor devices 201 is also six.

[0178] The housing 350 has a sealed inner cavity 351. In this embodiment, the housing 350 is provided with current-limiting grooves corresponding to each power semiconductor device 201. The power semiconductor device 201 is received and fixed in the current-limiting groove, and the current-limiting groove has an opening. Specifically, in this embodiment, the housing 150 is also provided with a current-limiting plate 353 and current-limiting walls 354. Among them, the current-limiting plate 353 is located at the bottom of the power semiconductor device 201. The number of the current-limiting walls 354 is two. The two current-limiting walls 354 are arranged on both sides of the power semiconductor device 201 and are respectively fixedly connected to opposite ends of the current-limiting plate 353. The current-limiting plate 353 and the current-limiting walls 354 are respectively arranged at intervals with the power semiconductor device 201.

[0179] The housing 350 further includes a front cover 355 and a rear cover 356 which are spaced apart from each other. The current-limiting plate 353 and the current-limiting walls 354 are respectively fixedly connected to the front cover 355 and the rear cover 356. Thus, for the same power semiconductor device 201, the current-limiting plate 353, the two current-limiting walls 354, a partial structure of the front cover 355, and a partial structure of the rear cover 356 around it jointly enclose to form a current-limiting groove. It should be noted that in this embodiment, regarding "the current-limiting plate 353 is located at the bottom of the power semiconductor device 201", it can be understood that the current-limiting plate 353 is arranged at an interval with the power semiconductor device 201 along a direction. And "the two current-limiting walls 354 are arranged on both sides of the power semiconductor device 201", it can be understood that the two current-limiting walls 354 are located on the opposite sides of the same power semiconductor device 201 along a direction perpendicular to the direction in which the current-limiting plate 353 is arranged at an interval with the power semiconductor device 201.

[0180] Thus, in Figure 9 the schematic illustration, the current-limiting plate 353 is arranged at an interval with the power semiconductor device 201 along the direction of gravity, and the two current-limiting walls 355 are located on the opposite sides of the power semiconductor device 201 along the horizontal direction. At this time, the opening of the formed current-limiting groove faces upward against the direction of gravity. Or it can be described as that the power semiconductor device 201 is fixed in the current-limiting groove with an upper opening. In some other embodiments, the opening of the current-limiting groove can also face downward along the direction of gravity, or be arranged in any direction.

[0181] The housing 350 is provided with a first communication hole 3513 and a second communication hole 3514. The first pipeline 310 is communicated to the inner cavity 351 through the first communication hole 3513, and the second pipeline 320 is communicated to the inner cavity 351 through the second communication hole 3514. In one embodiment, the first communication hole 3513 is located above the second communication hole 3514. In the illustrated schematic illustration, the first communication hole 3513 is also located at the top of the housing 350, that is, at the top position of the inner cavity 351.

[0182] Please refer to Figure 10, for the heat dissipation device 300 provided in this embodiment, the second communication hole 3514 also communicates with each current limiting groove. That is, in this embodiment, the second pipeline 320 communicates with the current limiting groove. The cooling working fluid cooled by the condenser 340 directly flows into the current limiting groove through the second pipeline 320, and after heat exchange with the power semiconductor device 201, it enters other areas of the inner cavity 351 from the opening of the current limiting groove.

[0183] Similar to the principle of the above heat dissipation device 100, in the heat dissipation device 300 provided in this embodiment, when the cooling working fluid directly enters the current limiting groove through the second pipeline 320, it can reach the power semiconductor device 201 in a relatively short path and form heat exchange with the power semiconductor 201. At this time, the temperature of the cooling working fluid is relatively low, and its heat dissipation effect on the power semiconductor device 201 is better. After the cooling working fluid that has completed heat exchange enters other areas of the inner cavity 351 from the opening of the current limiting groove, it can flow upward and enter the first pipeline 310 through the first communication hole 3513, and then flow back to the condenser 340 for cooling.

[0184] Compared with the heat dissipation method in the prior art where the cooling working fluid directly enters the inner cavity 151a, the heat dissipation device 300 provided in this embodiment can also form a better heat dissipation effect on the power semiconductor device 201.

[0185] In Figure 10 's schematic diagram, the power semiconductor device 201 is fixed on the rear cover 356, and the second communication hole 3514 is arranged at the front cover 355. The second pipeline 320 sends the cooling working fluid into the current limiting groove from one side of the front cover 355. Further, the second communication hole 3514 can be aligned with the geometric center of the power semiconductor device 201, so that the cooling working fluid can diffuse from the center of the power semiconductor device 201 to the surroundings and form a more uniform heat exchange effect.

[0186] It can be understood that the power semiconductor device 201 can also be fixed on one side of the front cover 355, and the second communication hole 3514 is arranged on one side of the rear cover 356 and is located in the current limiting groove (as Figure 9 shown). Such a structure can also form a good heat dissipation effect on the power semiconductor device 201.

[0187] In one embodiment, the condenser 340 is located above the evaporator 330 along the gravity direction. Thus, the cooling working fluid in the condenser 340 can be transported to the current limiting groove through the second pipeline 320 under the action of gravity. After the cooling working fluid dissipates heat from the power semiconductor device 201, it flows into the first pipeline 310 through the opening and flows back to the condenser 340 against the gravity direction for cooling. At this time, the heat dissipation device 300 also forms the form of a gravity heat pipe, and the circulating flow of the cooling working fluid can be realized through its own phase change, reducing energy consumption.

[0188] In one embodiment, the opening of the current-limiting groove faces upward against the direction of gravity. Thus, the cooling working fluid in the current-limiting groove can form an immersion effect on the power semiconductor device 201 under the action of gravity, and the relatively low-temperature cooling working fluid flowing in from the second pipeline 320 can make more sufficient contact with the power semiconductor device 201, improving the heat dissipation capacity of the heat dissipation device 300.

[0189] In Figure 10 the embodiment, the power semiconductor devices 201 are also arranged vertically along the direction of gravity, that is, the first power semiconductor device 201a is formed above and the second power semiconductor device 201b is formed below. The current-limiting grooves are also arranged in an up-and-down distribution structure. Each current-limiting groove houses a second communication hole 3514. At this time, the same second pipeline 320 can be respectively connected to the upper and lower second communication holes 3514 and simultaneously supply the cooling working fluid to the upper and lower current-limiting grooves. Such a structure can reduce the number of second pipelines 320 and can also ensure the heat dissipation effect of the heat dissipation device 300.

[0190] In the present application Figure 9 and Figure 10 in the embodiment of the heat dissipation device 300 shown, the structure of a plurality of support columns 358 can also be set, and the structure of a water pump 360 can be set, or the condenser 340 can be arranged above the evaporator 330 to form a self-circulation flow effect through the change in the density of the cooling working fluid itself. And, in some embodiments, on the front cover 355 or the rear cover 356, a structure similar to the bump 1551 in the embodiment of the heat dissipation device 100 can also be set to increase the nucleation points of the power semiconductor device 201. The specific structures and effects of the above embodiments are respectively similar to the specific structures and effects of their corresponding embodiments in the heat dissipation device 100, and are not described in detail herein one by one.

[0191] Please refer to Figure 11 the structure of another heat dissipation device 400 provided by the present application shown. The heat dissipation device 400 also includes a plurality of elements the same as those of the heat dissipation device 100. Therefore, similar element numbers are the same, and the reference numerals start with "4" instead of "1".

[0192] In Figure 11 the embodiment shown, the heat dissipation device 400 also includes a first pipeline 410, a second pipeline 420, an evaporator 430, and a condenser 440. The first pipeline 410 is connected between the evaporator 430 and the condenser 440, and the second pipeline 420 is also connected between the evaporator 430 and the condenser 440. A cooling working fluid is injected into the heat dissipation device 400, thereby forming a cooling working fluid circulation path of "evaporator 430 - first pipeline 410 - condenser 440 - second pipeline 420 - evaporator 430".

[0193] The evaporator 430 includes a housing 450, and a heating element 201 is fixed inside the housing 450. After the cooling refrigerant forms a heat exchange with the heating element 201 inside the housing 450, it flows from the first pipeline 410 to the condenser 440. After the condenser 440 cools down the cooling refrigerant, the cooling refrigerant flows back to the evaporator 430 through the second pipeline 420 to form a heat exchange with the heating element 201 again.

[0194] In this embodiment, the heating element 201 can also correspond to the power semiconductor device 201 in the above-mentioned inverter 200. And in Figure 11 the schematic illustration, the number of the power semiconductor devices 201 is also six.

[0195] The housing 450 has a sealed inner cavity 451, and the housing 450 further includes a front cover 455 and a rear cover 456 which are arranged at intervals. The inner cavity 451 is formed between the front cover 455 and the rear cover 456. And in this embodiment, please refer to Figure 12 for cooperation. The evaporator 430 further includes a middle partition plate 459. The middle partition plate 459 is located in the inner cavity 451 and is used for separating the inner cavity 451 into a front cavity 4511 and a rear cavity 4512. Among them, the front cavity 4511 is located between the middle partition plate 459 and the front cover 455, and the rear cavity 4512 is located between the middle partition plate 459 and the rear cover 456. In the illustrated embodiment, the housing 450 is a cuboid, and the middle partition plate 459 is arranged along the gravity direction. The front cavity 4511 and the rear cavity 4512 are also respectively formed into rectangular cavities. In some other embodiments, the middle partition plate 459 can also be inclined so that the front cavity 4511 and the rear cavity 4512 are respectively formed into right trapezoidal cavities, which does not affect the function realization of the heat dissipation device 100 of the present application.

[0196] In this embodiment, multiple power semiconductor devices 201 are all fixed inside the front cavity 4511. Specifically, multiple power semiconductor devices 201 can be fixed on the middle partition plate 459 (as Figure 13 shown), or can be fixed on the front cover 455. The first pipeline 410 communicates with the front cavity 4511, and the second pipeline 420 communicates with the rear cavity 4512. It can be understood that the housing 450 is provided with a first communication hole 4513 and a second communication hole 4514. The first pipeline 410 communicates with the front cavity 4511 through the first communication hole 4513, and the second pipeline 420 communicates with the rear cavity 4512 through the second communication hole 4514. In one embodiment, the first communication hole 4513 is vertically above the second communication hole 4514. In the illustrated schematic illustration, the first communication hole 4513 is also located at the top of the housing 450, that is, at the top position of the inner cavity 451.

[0197] In the heat dissipation device 400 of this embodiment, the housing 450 is provided with current limiting grooves corresponding to each power semiconductor device 201, and the power semiconductor device 201 is received and fixed in the current limiting grooves. That is, a current limiting groove for receiving the power semiconductor device 201 is provided in the front cavity 4511 of the housing 450. Specifically, in this embodiment, the housing 450 also includes a current limiting plate 453 and current limiting walls 454. Among them, the current limiting plate 453 is located at the bottom of the power semiconductor device 201, and the number of current limiting walls 454 is two. The two current limiting walls 454 are arranged on both sides of the power semiconductor device 201 and are respectively fixedly connected to opposite ends of the current limiting plate 453. The current limiting plate 453 and the current limiting walls 454 are respectively arranged at intervals with the power semiconductor device 201. It can be understood that in this embodiment, the current limiting plate 453 is located at the bottom of the power semiconductor device 201, which can also be understood as the current limiting plate 453 being arranged at intervals with the power semiconductor device 201 in one direction.

[0198] The current limiting plate 453 is respectively fixedly connected to the front cover 455 and the middle partition plate 459, and the current limiting walls 454 are also respectively fixedly connected to the front cover 455 and the middle partition plate 459. Thus, for the same power semiconductor device 201, the current limiting plate 453, the two current limiting walls 454, a partial structure of the front cover 455, and a partial structure of the middle partition plate 459 around it jointly enclose to form a current limiting groove. In Figure 11 the schematic illustration, the current limiting plate 453 is also located below the power semiconductor device 201 along the gravity direction, and the current limiting groove forms a structure with an upward opening at the periphery of the power semiconductor device 201. It can also be described as the power semiconductor device 201 being fixed in the current limiting groove with an upper opening.

[0199] Please refer to Figure 14 the internal structure on one side of the rear cavity 4512 shown in the figure. A drainage hole 4591 is also opened in the middle partition plate 459, and the drainage hole 4591 is used to connect the front cavity 4511 and the rear cavity 4512. And in this embodiment, the drainage hole 4591 is also connected to the inside of the current limiting groove, that is, the drainage hole 4591 is located between the power semiconductor device 201 and its corresponding current limiting plate 453 and / or current limiting wall 454. Based on the above description of the circulation path of the cooling working medium, the cooling working medium cooled by the condenser 440 first flows into the rear cavity 4512 near the rear cover 456 through the second pipeline 420. Then, the cooling working medium can pass through the drainage hole 4591 and then enter the current limiting groove in the front cavity 4511 to form a heat exchange with the power semiconductor device 201.

[0200] Since the drainage hole 4591 is located between the power semiconductor device 201 and the current-limiting plate 453 and / or the current-limiting wall 454, when the cooling working fluid enters the front cavity 4511 from the rear cavity 4512 through the drainage hole 4591, the cooling working fluid directly enters the current-limiting groove, and after heat exchange with the power semiconductor device 201, it enters other areas of the front cavity 4511 from the opening of the current-limiting groove.

[0201] Similar to the principle of the above heat dissipation device 300, in the heat dissipation device 400 provided in this embodiment, when the opening of the current-limiting groove faces upward in the direction of gravity, the cooling working fluid enters the current-limiting groove through the second pipeline 420 and the rear cavity 4512 in sequence. It can reach the power semiconductor device 201 in a relatively short path, and under the action of gravity, it can stay in the current-limiting groove for a relatively long time. After sufficient heat exchange with the power semiconductor device 201, it then flows into other areas of the front cavity 4511. At this time, the temperature of the cooling working fluid is relatively low, and its heat dissipation effect on the power semiconductor device 201 is better. After the cooling working fluid that has completed heat exchange enters other areas of the front cavity 4511 from the upper opening of the current-limiting groove, it can flow upward and enter the first pipeline 410 through the first communication hole 3513, and then return to the condenser 440 for cooling. It should be noted that in some other embodiments, the opening of the current-limiting groove can also face any direction, as long as it is ensured that the cooling working fluid flowing in from the rear cavity 4512 can form heat exchange with the power semiconductor device 201 in a shorter flow path. Compared with the heat dissipation method in the prior art where the cooling working fluid directly enters the inner cavity 151a, the heat dissipation device 400 provided in this embodiment can also achieve a better heat dissipation effect on the power semiconductor device 201.

[0202] In Figure 13 's schematic diagram, the power semiconductor devices 201 can also be arranged vertically along the direction of gravity, that is, the first power semiconductor device 201a located above and the second power semiconductor device 201b located below are formed. The current-limiting grooves are also arranged in an up-and-down distribution structure. A structure with a drainage hole 4591 is provided between each current-limiting groove and the power semiconductor device 201. At this time, as Figure 14 shown, in the horizontal direction perpendicular to the direction of gravity, the first power semiconductor device 201a and the second power semiconductor device 201b form two mutually spaced projection areas 201a' and 201b' on the inner surface of the housing 450. The second communication hole 4514 through which the second pipeline 420 communicates with the housing 450 is also located on the same inner surface. Further, the second communication hole 4514 is also located between the two projection areas 201a' and 201b'.

[0203] Specifically, the cooling working fluid entering the rear cavity 4512 from the second communication hole 4514 can flow in two opposite directions. That is, in this embodiment, after the cooling working fluid enters the rear cavity 4512, it can flow in two different directions along the gravitational direction, i.e., upward and downward. Then, it flows into the current-limiting groove from the respective drainage holes 4591 corresponding to the first power semiconductor device 201a and the second power semiconductor device 201b, respectively, and then forms a heat dissipation effect on the first power semiconductor device 201a and the second power semiconductor device 201b, respectively. The cooling working fluid flowing in two opposite directions ensures the uniformity of heat dissipation for each power semiconductor device 201.

[0204] It can be understood that when the first power semiconductor device 201a and the second power semiconductor device 201b are arranged at intervals in the horizontal direction, the second communication hole 4514 can also be located between the projection areas of the two power semiconductor devices 201, enter from above and / or below the rear cavity 4512 along the gravitational direction, and then spread out to the left and right sides in the horizontal direction and flow into each power semiconductor device 201, which can also improve the uniformity of heat dissipation.

[0205] In Figure 14 In the schematic diagram, the number of the second pipelines 420 is two, and each second pipeline 420 is connected to a side plate 457, that is, the two second communication holes 4514 are respectively located on a side plate 457. The two second pipelines 420 can feed the cooling working fluid with a relatively low temperature from the opposite sides of the rear cavity 4512, which is beneficial to ensuring the temperature balance of the cooling working fluid in the rear cavity 4512.

[0206] For an embodiment, please refer to Figure 15a , the number of the drainage holes 4591 can be multiple, and the multiple drainage holes 4591 are spaced apart and distributed on the periphery of the power semiconductor device 201. Specifically, the multiple drainage holes 4591 can be arranged at intervals along the length direction of the current-limiting plate 453; and, the multiple drainage holes 4591 can also be arranged at intervals along the length direction of the current-limiting wall 454. Because the larger the total area of the drainage holes 4591, the more the cooling working fluid entering the current-limiting groove from the drainage holes 4591, and a better heat dissipation effect can be formed; on the other hand, the multiple drainage holes 4591 are spaced apart and distributed on the periphery of the power semiconductor device 201, which can make the cooling working fluid enter the current-limiting groove relatively uniformly along the outer contour of the power semiconductor device 201, and then the heat dissipation distribution of the power semiconductor device 201 is more uniform, and its heat dissipation effect can also be improved.

[0207] And in Figure 15bIn the illustrated embodiment, the shape of the drainage hole 4591 can also be strip-shaped. The strip-shaped drainage hole 4591 extends along the length direction of the flow-limiting plate 453; moreover, the strip-shaped drainage hole 4591 also extends along the length directions of the two flow-limiting walls 454. The strip-shaped drainage hole 4591 also provides a relatively large area for allowing more and relatively uniform entry of the cooling working fluid into the flow-limiting groove. In Figure 15b the schematic illustration, the respective strip-shaped drainage holes 4591 are also sequentially communicated.

[0208] In one embodiment, the condenser 440 can also be disposed above the evaporator 430 along the direction of gravity to form the form of a gravity heat pipe. The cooling working fluid in the condenser 440 is delivered to the flow-limiting groove through the second pipeline 420 under the action of gravity. After the cooling working fluid dissipates heat from the power semiconductor device 201, it flows into the first pipeline 410 through the opening and returns to the condenser 440 against the direction of gravity for cooling.

[0209] In the present application Figures 11 to 15b In the illustrated embodiment of the heat dissipation device 400, the structure of a plurality of support columns 458 can also be provided, or the structure of a water pump 460 can be provided. Moreover, in some embodiments, on the inner side wall of the front cover 455 or the middle partition plate 459, a structure similar to the bump 1551 in the embodiment of the heat dissipation device 100 can also be provided to increase the nucleation points on the power semiconductor device 201. The specific structures and effects of the above embodiments are respectively similar to those of the corresponding embodiments in the heat dissipation device 100, and are not described in detail herein one by one.

[0210] It should be noted that since the structure of the middle partition plate 459 is provided in the heat dissipation device 400 of this embodiment, when the support column 458 is provided in the housing 450, the support column 458 can be fixedly connected between the front cover 455 and the middle partition plate 459 to enhance the structural stability of the housing 450. In some embodiments, the support column 458 can also pass through the middle partition plate 459 and be fixedly connected between the front cover 455 and the rear cover 456. At this time, the support column 458 can be fixedly connected to the front cover 455, the middle partition plate 459, and the rear cover 456 simultaneously to further improve the structural stability of the housing 450.

[0211] On the other hand, in each embodiment of the present application, the front cover and the rear cover are only used to designate two plate-like structures spaced apart from each other in the housing. The specific naming of "front" and "rear" only refers to the relative positional relationship between the two plate-like structures. The present application's heat dissipation device does not strictly limit the specific orientations of the front cover and the rear cover in the power converter. That is to say, the present application's heat dissipation device can be fixed to the power converter through the front cover, or can be fixed to the power converter through the rear cover, without affecting the function implementation of the present application's radiator.

[0212] Please refer to Figure 16The structure of another heat dissipation device 500 provided by the present application is shown. The heat dissipation device 500 also includes a plurality of elements identical to those of the heat dissipation device 100, so similar elements have the same numbering, and the reference numerals start with "5" instead of "1".

[0213] In Figure 16 the illustrated embodiment, the heat dissipation device 500 also includes a first pipeline 510, a second pipeline 520, an evaporator 530, and a condenser 540. The first pipeline 510 is connected between the evaporator 530 and the condenser 540, and the second pipeline 520 is also connected between the evaporator 530 and the condenser 540. A cooling refrigerant is injected into the heat dissipation device 500, thereby forming a cooling refrigerant circulation path of "evaporator 530 - first pipeline 510 - condenser 540 - second pipeline 520 - evaporator 530".

[0214] The evaporator 530 includes a housing 550, and a heating element 201 is fixed inside the housing 550. After the cooling refrigerant forms a heat exchange with the heating element 201 inside the housing 550, it flows from the first pipeline 510 into the condenser 540. After the condenser 540 cools down the cooling refrigerant, the cooling refrigerant flows back into the evaporator 530 through the second pipeline 520 to form a heat exchange with the heating element 201 again.

[0215] In this embodiment, the heating element 201 can also correspond to the power semiconductor device 201 in the above-mentioned inverter 200. And in Figure 16 the illustration, the number of the power semiconductor devices 201 is also six.

[0216] The housing 550 has a sealed inner cavity 551, and the housing 550 is provided with a first communication hole 5513 and a second communication hole 5514. The first pipeline 510 is connected to the inner cavity 551 through the first communication hole 5513, and the second pipeline 520 is connected to the inner cavity 551 through the second communication hole 5514. In one embodiment, the first communication hole 5513 is located above the second communication hole 5514 along the gravity direction. In the illustrated embodiment, the first communication hole 5513 is also located at the top of the housing 550, that is, at the top position of the inner cavity 551.

[0217] And in this embodiment, the housing 550 further includes a front cover 555 and a rear cover 556 that are spaced apart from each other. For an embodiment, please refer to Figure 17 , for the heat dissipation device 500 of the present application, each power semiconductor device 201 can be fixed on the rear cover 556. Correspondingly, a fitting area can be provided on the front cover 555, and the position of the fitting area is at least partially aligned with the power semiconductor device 201. The fitting area is provided with a convex block 5551. The convex block 5551 protrudes from the front cover 555 towards the power semiconductor device 201, and the end face of the convex block 5551 facing the power semiconductor device 201 is in contact with the power semiconductor device 201.

[0218] Please synchronously cooperate and refer to Figure 18 After the front cover 555 is assembled on the housing 550, the bump 5551 of the front cover 555 abuts against and contacts the power semiconductor device 201. In this embodiment, the bump 5551 is further provided with pores 5552, and the pores 5552 are at least located on the end face of the bump 5551 facing the power semiconductor device 201. Thus, the pores 5552 of the bump 5551 abut against and contact the power semiconductor device 201.

[0219] In Figure 19a In the schematic illustration, the pores 5552 can be a layer structure with a pore shape, or it can be described that the pores 5552 are formed by a plurality of holes 5553a with different sizes and irregular arrangements. When the pores 5552 of the bump 5551 are attached to the surface of the power semiconductor device 201, more nucleation points can be formed on the surface of the power semiconductor device 201. The cooling working fluid forms a better heat exchange effect at the nucleation points, thereby improving the heat dissipation effect of the cooling working fluid on the power semiconductor device 201.

[0220] Compared with the heat dissipation method in the prior art where the cooling working fluid directly enters the inner cavity 151a, the heat dissipation device 500 provided in this embodiment can also form a better heat dissipation effect on the power semiconductor device 201.

[0221] In one embodiment, the fitting area can also be completely aligned with the power semiconductor device 201, that is, the shape, size, and position of the fitting area are set corresponding to the power semiconductor device 201, so that the bump 5551 can be in full contact with the surface of the power semiconductor device 201. At this time, the number of nucleation points formed on the surface of the power semiconductor device 201 is more, and the heat dissipation effect of the cooling working fluid on the power semiconductor device 201 is better.

[0222] In one embodiment, the housing 550 is further provided with a structure of a plurality of spaced-apart support columns 558. The support columns 558 are similar in structure and effect to the support columns 158 in the heat dissipation device 100, and can hold the front cover 555 and the rear cover 556, and form a guiding and diverting effect on the cooling working fluid. In the heat dissipation device 500 of this embodiment, there is a first distance between any two adjacent support columns 558. This first distance can be understood as the closest spacing distance between two adjacent support columns 558.

[0223] At this time, when the pores 5552 of the bump 5551 are as Figure 19aAs shown, when formed by irregular arrangement of a plurality of holes 5553a, the inner diameter dimension of any hole 5553a is smaller than the first distance between two support columns 558. Such an arrangement can ensure that the pores 5552 are more densely arranged compared to the support columns 558, so as to ensure that the positions of the nucleation points are located at the pores 5552 of the bump 5551.

[0224] And when the pores 5552 of the bump 5551 are as Figure 19b or Figure 19c shown, when formed by the gaps between a plurality of spaced-apart protrusions ( Figure 19b shown as the support columns 5553b, Figure 19c shown as the lattice 5553c), the distance between any two adjacent protrusions is also smaller than the first distance. Similarly, it can ensure that the pores 5552 are more densely arranged, and ensure that the positions of the nucleation points are located at the pores 5552 of the bump 5551, thereby ensuring the heat dissipation effect of the cooling working fluid on the power semiconductor device 201.

[0225] It should be noted that in the Figure 17 and Figure 18 illustrations, the power semiconductor device 201 is fixed to the rear cover 556, and the bump 5551 protruding from the self-adhesive area is formed on the front cover 555. In some other embodiments, the power semiconductor device 201 can also be fixed to the front cover 555, and a fitting area at least partially aligned with the power semiconductor device 201 is provided on the rear cover 556. Then, a structure of a protruding bump 5551 is provided on the fitting area, and pores 5552 are provided on the bump 5551. Such an arrangement can also make the surface of the bump 5551 with pores 5552 contact the power semiconductor device 201, and form a plurality of nucleation points on the power semiconductor device 201, improving the heat dissipation effect of the cooling working fluid on the power semiconductor device 201.

[0226] In one embodiment, the condenser 540 is located above the evaporator 530 along the gravity direction. Thus, the cooling working fluid in the condenser 540 can be delivered to the current-limiting groove through the second pipeline 520 under the action of gravity. After the cooling working fluid dissipates heat from the power semiconductor device 201, it flows into the first pipeline 510 through the opening and returns to the condenser 540 against the gravity direction for cooling. At this time, the heat dissipation device 500 is also formed in the form of a gravity heat pipe, and the circulation flow of the cooling working fluid can be realized through its own phase change, reducing energy consumption.

[0227] In the embodiment of the heat dissipation device 500 shown in the present application Figures 16 to 19c the structure of the water pump 560 can also be set, and then the water pump 560 provides power for the circulation flow of the cooling working fluid. The specific structures and effects of the above embodiments are respectively similar to those of the corresponding embodiments in the heat dissipation device 100, and are not elaborated one by one in this specification.

[0228] The above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, such as reducing or adding structural members, changing the shape of structural members, etc., which should all be covered within the protection scope of the present application; without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A heat dissipation device, characterized in that, It includes an evaporator and a condenser, as well as a first pipeline and a second pipeline respectively connected between the evaporator and the condenser; The evaporator includes a housing and a partition. The housing has a sealed inner cavity. The partition divides the inner cavity into a first sub-cavity and a second sub-cavity. The first pipeline is connected to the first sub-cavity, the second pipeline is connected to the second sub-cavity, and the first sub-cavity is located above the second sub-cavity along the direction of gravity; A heating element is also fixed in the first sub-cavity. The partition is provided with a diversion hole for communicating the first sub-cavity and the second sub-cavity. At least part of the diversion hole faces the heating element located in the first sub-cavity. The cooling working medium in the condenser is transported to the second sub-cavity through the second pipeline. The cooling working medium flows into the first sub-cavity through the diversion hole, dissipates heat from the heating element, and then flows back to the condenser through the first pipeline for cooling. The heating element at least includes a first heating element and a second heating element. The second heating element is located between the first heating element and the partition. The housing also includes a current-limiting plate. The current-limiting plate is located between the first heating element and the second heating element. The current-limiting plate is provided with a plurality of through slits, and the slits are used to block the bubbles flowing towards the first heating element.

2. The heat dissipation device according to claim 1, characterized in that, The cooling working medium in the condenser is transported to the second sub-cavity through the second pipeline under the action of gravity. The cooling working medium flows into the first sub-cavity through the diversion hole against the direction of gravity, dissipates heat from the heating element, and then flows back to the condenser through the first pipeline against the direction of gravity for cooling.

3. The heat dissipation device according to claim 1, characterized in that, The diversion hole includes a plurality of diversion sub-holes. The plurality of diversion sub-holes are arranged at intervals and are located between the heating element and the partition.

4. The heat dissipation device according to claim 1, characterized in that, The housing also includes a current-limiting wall. The current-limiting wall is fixedly connected to the current-limiting plate and is located on at least one side of the first heating element. The current-limiting wall is also used to block the bubbles flowing towards the first heating element.

5. The heat dissipation device according to any one of claims 1 to 4, characterized in that, The housing includes a front cover and a rear cover that are fixedly spaced apart. A plurality of spaced-apart support columns are also provided in the inner cavity. The heating element is fixed to the front cover or the rear cover. Opposite ends of each support column are respectively fixedly connected to the front cover and the rear cover. The support columns are used to improve the structural stability of the housing.

6. The heat dissipation device according to claim 5, characterized in that, The heating element is fixed to the inner side wall of one of the front cover and the rear cover. The inner side wall of the other cover is provided with a fitting area. The position of the fitting area is at least partially aligned with the heating element. The fitting area is provided with a convex block, and the convex block protrudes towards the heating element and contacts the heating element. The convex block also has pores, and the pores are at least located on the end surface of the convex block in contact with the heating element.

7. The heat dissipation device according to claim 6, characterized in that, There is a first distance between any two adjacent support columns. The pores of the convex block are formed by irregular arrangement of a plurality of holes. The inner diameter size of any one of the holes is smaller than the first distance; or The bump includes a plurality of protruding portions arranged at intervals, and the gaps between the plurality of protruding portions form the pores, and the distance between any two adjacent protruding portions is less than the first distance.

8. The heat dissipation device according to any one of claims 1 to 4, characterized in that, The heat dissipation device includes a water pump, the pump port of the water pump is communicated with the first pipeline and / or the second pipeline, and the water pump is used to drive the circulating flow of the cooling medium.

9. A heat dissipation device, characterized in that, It includes an evaporator and a condenser, and a first pipeline and a second pipeline respectively communicated between the evaporator and the condenser; The evaporator includes a housing, the housing has a sealed inner cavity, a current-limiting groove is provided in the inner cavity, the current-limiting groove has an opening, a heating element is fixed in the current-limiting groove, the second pipeline is communicated into the current-limiting groove through a second communication hole, the opening of the current-limiting groove faces upward against the gravity direction, and the distance between the second communication hole and the opening along the gravity direction is greater than the distance between the heating element and the opening; The cooling medium in the condenser is transported to the current-limiting groove through the second pipeline. After the cooling medium dissipates heat from the heating element, it flows back to the condenser through the first pipeline for cooling. The heating element at least includes a first heating element and a second heating element. The second heating element is located below the first heating element along the gravity direction. The bottom of the current-limiting groove of the first heating element includes a current-limiting plate, and the current-limiting plate is located between the first heating element and the second heating element.

10. The heat dissipation device according to claim 9, characterized in that, The housing includes a front cover and a rear cover fixed at intervals, and a current-limiting plate and a current-limiting wall connected between the front cover and the rear cover; The heating element is located between the front cover and the rear cover and is fixed to the front cover or the rear cover. The current-limiting plate is located at the bottom of the first heating element, and the two current-limiting walls are located on both sides of the first heating element. The front cover, the rear cover, the current-limiting plate and the current-limiting wall jointly enclose to form the current-limiting groove.

11. The heat dissipation device according to claim 9 or 10, characterized in that, The cooling medium in the condenser is transported to the current-limiting groove through the second pipeline under the action of gravity. After the cooling medium dissipates heat from the heating element, it flows into the first pipeline through the opening and flows back to the condenser against the gravity direction for cooling.

12. A heat dissipation device, characterized in that, It includes an evaporator and a condenser, and a first pipeline and a second pipeline respectively communicated between the evaporator and the condenser; The evaporator includes a housing, the housing has a sealed inner cavity, the housing includes a front cover, a middle partition plate and a rear cover arranged at intervals in sequence, the middle partition plate divides the inner cavity into a front cavity close to the front cover and a rear cavity close to the rear cover, the first pipeline is communicated with the front cavity, and the second pipeline is communicated with the rear cavity; A current-limiting groove is provided in the front cavity, a heating element is fixed in the current-limiting groove, the current-limiting groove has an opening, and a partial area of the front cover and a partial area of the middle partition plate are also respectively used to form the current-limiting groove; The middle partition plate is provided with a drainage hole communicating between the current-limiting groove and the rear cavity. The cooling working medium in the condenser is transported to the rear cavity through the second pipeline. The cooling working medium flows into the current-limiting groove through the drainage hole. After dissipating heat from the heating element, it flows back to the condenser through the first pipeline for cooling. The opening of the current-limiting groove faces upward against the direction of gravity. The maximum distance along the direction of gravity between the drainage hole and the opening is greater than the minimum distance between the heating element and the opening. The heating element at least includes a first heating element and a second heating element. The second heating element is located below the first heating element along the direction of gravity. The bottom of the current-limiting groove of the first heating element includes a current-limiting plate, and the current-limiting plate is located between the first heating element and the second heating element.

13. The heat dissipation device according to claim 12, characterized in that, The housing includes a current-limiting plate and a current-limiting wall connected between the front cover and the middle partition plate; The heating element is fixed to the front cover or the middle partition plate. The current-limiting plate is located at the bottom of the first heating element, and the two current-limiting walls are located on both sides of the first heating element. The front cover, the middle partition plate, the current-limiting plate, and the current-limiting wall jointly enclose to form the current-limiting groove.

14. The heat dissipation device according to claim 13, characterized in that, The drainage holes are multiple, and the multiple drainage holes are arranged at intervals along the length direction of the current-limiting wall and / or the current-limiting wall; or The drainage hole is strip-shaped, and the strip-shaped drainage hole extends along the length direction of the current-limiting wall and / or the current-limiting wall.

15. The heat dissipation device according to any one of claims 12 to 14, characterized in that The cooling working medium in the condenser is transported to the current-limiting groove through the second pipeline under the action of gravity. After the cooling working medium dissipates heat from the heating element, it flows into the first pipeline through the opening and flows back to the condenser against the direction of gravity for cooling.

16. The heat dissipation device according to any one of claims 12 to 14, characterized in that The heating element at least includes a first heating element and a second heating element. The first heating element and the second heating element are fixed at intervals. In the direction perpendicular to the direction in which the first heating element and the second heating element are arranged at intervals, the first heating element and the second heating element form two mutually spaced projection areas on the inner surface of the housing; The second pipeline has a second communication hole communicating with the housing. The second communication hole and the two projection areas are located on the same inner surface of the housing, and the second communication hole is located between the two projection areas.

17. The heat dissipation device according to claim 16, characterized in that The first heating element is located above the second heating element along the direction of gravity. The housing further includes two opposite side plates. The two opposite side plates are respectively arranged on both sides of the front cover and are respectively connected between the front cover and the rear cover. The number of the second pipelines is two, and each second pipeline is connected to one of the side plates.

18. A heat dissipation device, characterized in that It includes an evaporator and a condenser, and a first pipeline and a second pipeline respectively communicating between the evaporator and the condenser; The evaporator includes a housing having a sealed inner cavity. The housing further includes a front cover and a rear cover that are fixedly spaced apart. A heating element is fixed to the inner side wall of one of the front cover and the rear cover, and a fitting area is provided on the inner side wall of the other cover. The position of the fitting area is at least partially aligned with the heating element. The fitting area is provided with a protrusion that protrudes towards the heating element and contacts the heating element. The protrusion also has pores, and the pores are at least located on the end face where the protrusion contacts the heating element. The heating element at least includes a first heating element and a second heating element. The second heating element is located below the first heating element in the direction of gravity. The housing further includes a current-limiting plate located between the first heating element and the second heating element. The current-limiting plate is provided with a plurality of through holes and slots for blocking the bubbles flowing towards the first heating element. The cooling working medium in the condenser is transported to the inner cavity through the second pipeline. The cooling working medium flows back to the condenser through the first pipeline for cooling. Part of the cooling working medium dissipates heat from the heating element at the pores of the protrusion. The inner cavity has a plurality of spaced-apart support columns. Opposite ends of each support column are fixedly connected to the front cover and the rear cover respectively. There is a first distance between any two adjacent support columns. The pores of the protrusion are formed by irregular arrangement of a plurality of holes, and the inner diameter of any one of the holes is smaller than the first distance; or The protrusion includes a plurality of spaced-apart protrusion parts, and the gaps between the plurality of protrusion parts form the pores. The distance between any two adjacent protrusion parts is smaller than the first distance.

19. The heat dissipation device according to claim 18, characterized in that The cooling working medium in the condenser is transported to the inner cavity under the action of gravity through the second pipeline. After the cooling working medium dissipates heat from the heating element, it flows back to the condenser through the first pipeline against the direction of gravity for cooling.

20. A power converter, characterized in that It includes a power semiconductor device and a heat dissipation device according to any one of claims 1 to 19. The power semiconductor device is fixed in the inner cavity of the heat dissipation device as the heating element, and the heat dissipation device is used to dissipate heat from the power semiconductor device.

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