Power conversion device

Abstract

The embodiment of the invention provides power conversion equipment, and relates to the technical field of power electronics. The power conversion equipment comprises a shell, a circuit board, a radiator and a first heat exchanger, a power cavity is formed in the shell, a heat dissipation cavity is formed outside the shell, the shell comprises a partition plate located between the power cavity and the heat dissipation cavity, an opening is formed in the partition plate, the circuit board is arranged in the power cavity, and a first power device is arranged on the side, facing the opening, of the circuit board; the radiator is arranged in the heat dissipation cavity and comprises a first substrate and a first heat dissipation part, the first substrate is arranged at the opening and makes contact with the first power device, a first gas-liquid channel is formed in the first substrate, and a second gas-liquid channel communicated with the first gas-liquid channel is formed in the first heat dissipation part; a cooling working medium for gas-liquid conversion is arranged in the first gas-liquid channel; the first heat exchanger is located in the power cavity or the heat dissipation cavity. According to the technical scheme, targeted heat dissipation can be carried out on devices which are seriously heated in the power conversion equipment, so that the power conversion equipment stably operates.

Description

Power conversion device

[0001] The present application claims priority from the Chinese Patent Application No. 202410564999.6 filed on April 30, 2024, and entitled "Power conversion device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of power electronics, in particular to a power conversion device. BACKGROUND

[0003] An inverter is a power conversion device capable of converting direct current into alternating current, and the inverter and other power conversion devices generate a large amount of heat during use. With the development of the times, the demand for heat dissipation of inverters and other power conversion devices has increased dramatically.

[0004] In the related art, the entire power conversion device is cooled by a whole cooling method. However, the power conversion device includes a plurality of devices with high power, such as high-power chips. These devices generate a large amount of heat, and the cooling method of the related art cannot accurately cool these devices, which affects the stability of the operation of the power conversion device. SUMMARY

[0005] The present application provides a power conversion device that can accurately cool the devices that generate a large amount of heat in the power conversion device, so that the power conversion device can operate stably.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The application provides a power conversion device, which comprises a shell, a circuit board, a heat sink and a first heat exchanger, a sealed power cavity is formed in the shell, an open ventilation heat dissipation cavity is formed outside the shell, the shell comprises a partition plate between the power cavity and the heat dissipation cavity, the protection level of the power cavity is higher than that of the heat dissipation cavity, an opening is arranged on the partition plate, the circuit board is arranged in the power cavity, a first power device is mounted on the side of the circuit board facing the opening, the first power device constitutes a power conversion circuit of the power conversion device to convert the direct current input into the power conversion device; the heat sink is arranged in the heat dissipation cavity and comprises a first base plate and a first heat dissipation part, the first base plate is arranged at the opening and is in heat conduction contact with the first power device in the power cavity, the first heat dissipation part extends outward from the first base plate, a first gas-liquid channel is arranged in the first base plate, a second gas-liquid channel in communication with the first gas-liquid channel is arranged in the first heat dissipation part, a cooling medium for gas-liquid conversion is arranged in the first gas-liquid channel, and the included angle between the first gas-liquid channel and the second gas-liquid channel is 90 degrees or greater than 90 degrees and less than 180 degrees; an electronic device is mounted on the side of the circuit board opposite to the first power device, and the first heat exchanger is arranged in the power cavity or the heat dissipation cavity, and the first heat exchanger is used for transferring heat in the power cavity to the heat dissipation cavity to dissipate heat of the electronic device.

[0008] When the first power device in the power conversion device generates a large amount of heat, the heat on the first power device is transferred to the first base plate and heats the cooling medium in the first base plate, at least part of the cooling medium in the first gas-liquid channel changes into a gaseous state after the liquid cooling medium in the first gas-liquid channel is heated and heated, the gaseous cooling medium flows (rises) into the second gas-liquid channel of the first heat dissipation part, the open ventilation heat dissipation cavity facilitates heat exchange between the cooling medium in the first heat dissipation part and the outside, so that the gaseous cooling medium is rapidly cooled and condensed in the first heat dissipation part, gradually changes back to the liquid cooling medium, and then flows back into the first base plate, so as to continuously dissipate heat for the first power device. The application can be stably operated by targeted heat dissipation of the device generating a large amount of heat (for example, the first power device). The first gas-liquid channel and the second gas-liquid channel are arranged at a specific angle so that the cooling medium can flow back to the first base plate under the action of gravity.

[0009] In addition, the power cavity is sealed and has a higher protection level than the heat dissipation cavity, which can reduce the possibility of foreign matter entering the power cavity. In addition, the first base plate is arranged at the opening, that is, the first base plate can be in contact with the first power device, and can also shield the opening, further reducing the possibility of mutual interference between the heat dissipation cavity and the power cavity, so that the circuit board can be arranged in a chamber with relatively strong protection capability, thereby ensuring the safety of other devices on the basis of dissipating heat of the heating device and reducing the risk of failure of the power conversion device.

[0010] And, the circuit board is arranged in the power cavity, when the power conversion device is running, the circuit board and the electronic devices thereon generate a large amount of heat, the temperature in the power cavity is high, the first heat exchanger is arranged to exchange heat between the hot air in the power cavity and the cold air in the heat dissipation cavity, the temperature in the power cavity is reduced, and the power conversion device can be stably operated.

[0011] In an optional implementation, the first substrate extends in the vertical direction and protrudes the first heat dissipation portion, and the first power device is in thermal contact with the part of the first substrate protruding the first heat dissipation portion.

[0012] Through the above design, the overlapping area of the first heat dissipation portion and the first power device is small, and the first heat dissipation portion has more areas to exchange heat with the air in the heat dissipation cavity, the influence of the heat of the first power device on the condensation of the cooling medium in the first heat dissipation portion is reduced, the cooling medium can be quickly condensed in the first heat dissipation portion, and the heat dissipation effect of the heat sink is improved.

[0013] In an optional implementation, the first heat exchanger is located in the power cavity, the first heat exchanger has a first heat exchange channel formed therein, the first heat exchange channel is isolated from the power cavity, the first heat exchange channel has an inlet and an outlet arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are both in communication with the heat dissipation cavity.

[0014] The air in the heat dissipation cavity can enter the first heat exchange channel, then exchange heat with the hot air in the power cavity through the first heat exchanger, and the heat dissipation cavity is open to ventilation, so that the external air can continuously enter the first heat exchange channel, the temperature in the power cavity is reduced, and the power conversion device can be stably operated.

[0015] In an optional implementation, the first heat exchanger is located in the heat dissipation cavity, the first heat exchanger has a first heat exchange channel formed therein, the first heat exchange channel is isolated from the heat dissipation cavity, the first heat exchange channel has an inlet and an outlet arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are both in communication with the power cavity.

[0016] The first heat exchanger can make the hot air in the power cavity enter the first heat exchange channel, then exchange heat with the air in the heat dissipation cavity in the first heat exchanger, the heat dissipation cavity is arranged as an open ventilation structure, the air in the first heat exchange channel exchanges heat with sufficient cold air outside, the temperature in the power cavity is reduced, and the power conversion device can be stably operated. In addition, the first heat exchanger is arranged in the heat dissipation cavity, the heat dissipation efficiency is improved, and the heat dissipation speed is accelerated.

[0017] In an optional implementation, the first substrate extends in the vertical direction and protrudes the first heat dissipation portion, and the first heat exchanger overlaps the part of the first substrate protruding the first heat dissipation portion.

[0018] In order to make the first power device at least partially located below the first heat dissipation part, the first substrate extends downward and encloses a space with the first heat dissipation part, and the first heat exchanger is installed in the space, that is, the first heat exchanger is installed below the first heat dissipation part and overlaps with the part of the first substrate protruding from the first heat dissipation part, so that the heat sink and the first heat exchanger can be installed more compactly, and the space of the heat dissipation cavity is reduced.

[0019] In an optional embodiment, the first heat exchanger is located in the heat dissipation cavity, and the first heat exchanger includes heat-conducting plates connected to each other and heat dissipation fins, the heat-conducting plates are heat-conducting and attached to the first substrate, and the heat dissipation cavity is provided with a first fan for generating airflow through the heat dissipation fins.

[0020] The temperature of the electronic device rises, which increases the temperature of the power cavity, and the heat in the power cavity is transmitted to the heat-conducting plates through the first substrate, and the heat-conducting plates transmit the heat to the heat dissipation fins. The first fan blows air towards the heat dissipation fins, and the heat dissipation cavity is open to ventilation, so that the heat on the heat dissipation fins can be blown out of the heat dissipation cavity, that is, blown to the outside. The first fan rotates continuously, so that the heat dissipation fins can be continuously cooled, that is, the electronic device in the power cavity is indirectly cooled.

[0021] In an optional embodiment, the first substrate extends in the vertical direction and protrudes from the first heat dissipation part, the heat-conducting plates are heat-conducting and attached to the part of the first substrate protruding from the first heat dissipation part, and the heat dissipation fins are located below the first heat dissipation part.

[0022] The first substrate extends downward and encloses a space with the first heat dissipation part, and the first heat exchanger is installed in the space, so that the heat sink and the first heat exchanger can be installed more compactly, and the space of the heat dissipation cavity is reduced. In addition, the first power device is in contact with the protruding part of the first substrate, the heat-conducting plates are in contact with the protruding part of the first substrate, and the heat dissipation fins can also better cool the first power device.

[0023] In an optional embodiment, the partition plate is provided with a through hole, the first heat exchanger includes heat-conducting plates and a plurality of heat dissipation fins, the plurality of heat dissipation fins include first heat dissipation fins and second heat dissipation fins, the heat-conducting plates are arranged at the through hole, and the first heat dissipation fins and the second heat dissipation fins are respectively fixed to different plate surfaces of the heat-conducting plates; the heat-conducting plates and the first heat dissipation fins are located in the heat dissipation cavity, and the second heat dissipation fins extend into the power cavity through the through hole; or, the heat-conducting plates and the second heat dissipation fins are located in the power cavity, and the first heat dissipation fins extend into the heat dissipation cavity through the through hole; and the power cavity is provided with a second fan for generating airflow through the second heat dissipation fins.

[0024] The temperature of the electronic device is increased, and the temperature of the power cavity is increased. The second fan blows air towards the second heat dissipation fin, so that the heat in the power cavity can be conducted to the second heat dissipation fin. The heat in the power cavity is transmitted to the heat conduction plate through the second heat dissipation fin, and the heat is transmitted to the first heat dissipation fin through the heat conduction plate. Because the heat dissipation cavity is open to ventilation, the first heat dissipation fin can exchange heat with the outside, that is, the first heat dissipation fin can be continuously cooled, that is, the power cavity is cooled.

[0025] In an optional embodiment, the power cavity and the heat dissipation cavity are distributed along a first direction perpendicular to the vertical direction, and the heat sink further comprises a second substrate and a second heat dissipation part. The second substrate is distributed along the vertical direction and fixedly connected with the first substrate. The second heat dissipation part extends outward from the second substrate. The third gas-liquid channel is arranged in the second substrate. The fourth gas-liquid channel in communication with the third gas-liquid channel is arranged in the second heat dissipation part. The third gas-liquid channel is isolated from the first gas-liquid channel. The second power device is arranged on the side of the circuit board facing the opening. The second power device contacts the second substrate in the heat dissipation cavity. The cooling working medium for gas-liquid conversion is arranged in the third gas-liquid channel.

[0026] In the case where the first power device and the second power device have a height difference, the second substrate and the second heat dissipation part can better cool the second power device, reducing the possibility of affecting the normal operation of the power conversion device due to the serious heating of the second power device. In addition, the power cavity and the heat dissipation cavity are distributed along the first direction, and the first substrate and the second substrate are distributed along the vertical direction, which can reduce the size of the heat sink in the first direction, thereby reducing the size of the heat dissipation cavity in the first direction, and reducing the size of the power conversion device in the first direction.

[0027] In an optional embodiment, the power conversion device further comprises a second heat exchanger for transferring heat in the power cavity to the heat dissipation cavity. The first heat exchanger and the second heat exchanger are arranged in the heat dissipation cavity. The first heat dissipation part and the second heat dissipation part are distributed along the vertical direction. The first substrate protrudes downward towards the first heat dissipation part. The second substrate protrudes downward towards the second heat dissipation part. One of the first heat exchanger and the second heat exchanger is located between the first heat dissipation part and the second heat dissipation part, and the other is located below the one with lower height among the first heat dissipation part and the second heat dissipation part.

[0028] The hot air in the power cavity can exchange heat with the air in the heat dissipation cavity through the first heat exchanger and the second heat exchanger, which can further reduce the temperature in the power cavity, so that the power conversion device can stably operate. Since the first substrate protrudes downward to the first heat dissipation part and the second substrate protrudes downward to the second heat dissipation part, there is a surplus space below the first heat dissipation part and the second heat dissipation part. When the first heat exchanger and the second heat exchanger are arranged, the surplus space can be fully utilized, the installation of the heat dissipation part, the first heat exchanger and the second heat exchanger is more compact, the space in the heat dissipation cavity is fully utilized, and the size of the power device in the first direction is reduced.

[0029] In an alternative embodiment, the first heat exchanger is formed with a first heat exchange channel, and the second heat exchanger is formed with a second heat exchange channel. The inlet of the first heat exchange channel and the inlet of the second heat exchange channel are communicated with a first connecting pipe, and the outlet of the first heat exchange channel and the outlet of the second heat exchange channel are communicated with a second connecting pipe. The first connecting pipe and the second connecting pipe are located in the heat dissipation cavity and are communicated with the power cavity.

[0030] The hot air in the power cavity enters the first heat exchanger and the second heat exchanger through the first connecting pipe, respectively. The hot air in the first heat exchanger and the second heat exchanger exchanges heat with the air in the heat dissipation cavity, and then enters the second connecting pipe uniformly and returns to the power cavity through the second connecting pipe. The first heat exchanger and the second heat exchanger are communicated and fixed through the first connecting pipe and the second connecting pipe, which improves the integration of the first heat exchanger and the second heat exchanger. The first heat exchanger and the second heat exchanger do not need to be communicated with the power cavity respectively, which is conducive to the unified disassembly and assembly of the first heat exchanger and the second heat exchanger in the heat dissipation cavity.

[0031] In an alternative embodiment, the first heat exchange channel and the second heat exchange channel extend along the second direction. The first connecting pipe and the second connecting pipe are located on different sides of the one of the first heat dissipation part and the second heat dissipation part with lower height in the second direction. The first direction, the second direction and the vertical direction are perpendicular to each other.

[0032] The first heat dissipation part, the first heat exchanger, the second heat dissipation part and the second heat exchanger are alternately distributed. The upper space and the lower space of the one of the first heat dissipation part and the second heat dissipation part with lower height are utilized by the first heat exchanger and the second heat exchanger, respectively. The space on both sides of the one of the first heat dissipation part and the second heat dissipation part with lower height is utilized by the first connecting pipe and the second connecting pipe, respectively. Through the above layout mode, the space of the heat dissipation cavity can be more fully utilized, which is conducive to reducing the volume of the power device.

[0033] In an alternative embodiment, the power conversion device further comprises a protective cover, a heat dissipation cavity is formed in the protective cover, the protective cover is provided with a heat dissipation hole, the heat dissipation hole comprises an air inlet hole and an air outlet hole, one of the air inlet hole and the air outlet hole is located below the heat sink, and the other is located above the heat sink, and the heat dissipation cavity is provided with a first fan, which is used to drive the air entering through the air inlet hole to be discharged from the air outlet hole.

[0034] Under the action of the first fan, the air outside the protective cover can enter from the air inlet hole and be discharged from the air outlet hole, and the air inlet hole and the air outlet hole are respectively located on the upper and lower sides of the heat sink, so that the external air can fully pass through the heat sink, thereby improving the heat dissipation effect of the heat sink.

[0035] In an alternative embodiment, the first heat dissipation part comprises a plurality of first condenser pipes arranged at intervals, and the second heat dissipation part comprises a plurality of second condenser pipes arranged at intervals, a plurality of fins are arranged between adjacent two first condenser pipes and between adjacent two second condenser pipes, and the number of fins arranged in one of the first heat dissipation part and the second heat dissipation part closer to the air inlet hole is less than the number of fins arranged in the other farther from the air inlet hole.

[0036] The closer the air inlet hole is, the lower the temperature of the air, and when the air passes through one of the first heat dissipation part and the second heat dissipation part closer to the air inlet hole, heat exchange will occur, and the temperature of the air after heat exchange will rise, that is, in the heat dissipation cavity, the closer to the air outlet hole, the higher the temperature of the air. The first heat dissipation part and the second heat dissipation part closer to the air inlet hole are arranged with sparse fins, so that the air can pass through in large quantities, and the other farther from the air inlet hole is arranged with dense fins to enhance the heat dissipation capacity, so that the vertically arranged first heat dissipation part and second heat dissipation part can balance the heat dissipation.

[0037] In an alternative embodiment, the size of one of the first heat dissipation part and the second heat dissipation part closer to the air inlet hole in the first direction is smaller than the size of the other farther from the air inlet hole in the first direction.

[0038] The arrangement of different lengths is adopted, so that more cold air can blow to the one of the first heat dissipation part and the second heat dissipation part farther from the air inlet hole, thereby enhancing the overall heat dissipation capacity of the heat sink and balancing the heat dissipation of the first heat dissipation part and the second heat dissipation part.

[0039] In an alternative embodiment, the included angle between the first gas-liquid channel and the second gas-liquid channel is greater than 90 degrees and less than or equal to 160 degrees.

[0040] Through the above design, when the first gas-liquid channel is arranged in the vertical direction, the second gas-liquid channel is inclined upward from the first gas-liquid channel, so that the liquid in the first heat dissipation part flows back into the first substrate, thereby reducing the possibility of liquid cooling medium remaining in the first heat dissipation part.

[0041] In an alternative embodiment, the first power device is fixedly connected to the first substrate by a bolt, the circuit board is provided with a through hole for the head of the bolt to pass through, the shank of the bolt passes through the first power device and is threadedly connected to the first substrate, and the head of the bolt abuts against the surface of the first power device away from the first substrate.

[0042] The fixed connection of the first power device to the first substrate enables the first power device to be in full contact with the first substrate, reduces the possibility of a gap between the contact surfaces of the first power device and the first substrate, and enables the first power device to be tightly attached to the first substrate, thereby improving the heat dissipation effect of the first power device. In addition, the head of the bolt abuts against the first power device instead of the circuit board, thereby reducing the possibility of damage to the circuit board during the installation and fixation of the bolt and reducing the impact on the circuit board during the connection of the first power device and the first substrate.

[0043] In an alternative embodiment, part of the first substrate is directly opposite the plate surface of the partition plate, and the first substrate blocks at least part of the opening.

[0044] The heat dissipation cavity is in communication with the outside through the heat dissipation hole, and impurities from the outside may enter the heat dissipation cavity. If the impurities in the heat dissipation cavity enter the power cavity, the normal operation of the circuit board and the devices (e.g., electronic devices) thereon will be affected. In the present embodiment, part of the first substrate is directly opposite the plate surface of the partition plate, so that the first substrate and the partition plate overlap with each other. In this way, the first substrate can block at least part of the opening, thereby reducing the possibility of gas in the heat dissipation cavity entering the power cavity through the opening and reducing the possibility of external impurities affecting the operation of the circuit board and the devices thereon. In addition, the power cavity and the heat dissipation cavity are more independent of each other, and a high-protection cavity (i.e., the power cavity) is formed in the power conversion device to accommodate the circuit board, which is conducive to the normal operation of the power conversion device.

[0045] In an alternative embodiment, the inner wall surface of the first substrate surrounding the first gas-liquid passage includes a first wall surface and a second wall surface, the first wall surface and the second wall surface are oppositely arranged in the thickness direction of the first substrate, and a plurality of support members are arranged between the first wall surface and the second wall surface, one end of each support member is connected to or abuts against the first wall surface, and the other end of each support member is connected to or abuts against the second wall surface.

[0046] The first substrate is internally hollow, and the support members support the first wall surface and the second wall surface, that is, the internal chamber of the first substrate is supported by the support members, thereby reducing the possibility of the first substrate being crushed or bent and prolonging the service life of the first substrate. In addition, the possibility of failure of the heat sink due to local deformation is reduced.

[0047] In an alternative embodiment, the first substrate includes a base plate and a cover plate arranged along a first direction, the base plate is connected with the first power device, the cover plate is located on a side of the base plate away from the first power device, an edge of the cover plate is fixedly connected with an edge of the base plate, the cover plate is bulged towards a side away from the base plate, and a first gas-liquid channel is located between the cover plate and the base plate; one end of each support is integrally connected with the base plate, and the other end is connected with or abuts against the cover plate; the plurality of supports are divided into a plurality of support groups arranged along a vertical direction, each support group includes a plurality of supports arranged along a second direction, the first direction, the second direction and the vertical direction are perpendicular to each other; a flow equalization channel extending along the second direction is formed between two adjacent support groups, the flow equalization channel is in communication with the second gas-liquid channel; the upward surfaces of the plurality of supports in each support group along the vertical direction are flush, the downward surfaces of the plurality of supports in each support group along the vertical direction are flush, and the upward surface and the downward surface of each support along the vertical direction are parallel.

[0048] Through the above design, the base plate and the plurality of support groups thereon are conveniently extruded. For example, the base plate and the plurality of support groups thereon are produced by extrusion, and each support group is then separated into a plurality of supports by turning (or other processing methods), which is conducive to improving the production and processing efficiency of the first substrate.

[0049] In an alternative embodiment, the heat sink further includes a flow collection portion, the flow collection portion is arranged in the heat dissipation cavity and connected with an end of the first heat dissipation portion away from the first substrate, the second gas-liquid channel includes a plurality of sub-channels, and the flow collection portion is provided with a flow collection channel in communication with different sub-channels of the second gas-liquid channel, so as to enable the different sub-channels of the second gas-liquid channel to communicate with each other.

[0050] In some cases, the second gas-liquid channel has a plurality of different gas-liquid channels, and the flow collection portion is arranged in the heat sink, so as to enable the different gas-liquid channels of the second gas-liquid channel to communicate with each other, and enable the cooling working medium in the different gas-liquid channels to flow into the flow collection portion, which is conducive to the condensation and reflux of the cooling working medium.

[0051] In an alternative embodiment, the heat sink further includes a reflux pipe, the reflux pipe is arranged below the first heat dissipation portion, one end of the reflux pipe is in communication with the first gas-liquid channel, and the other end is in communication with the flow collection channel.

[0052] When the cooling working medium is condensed after being dissipated in the first heat dissipation portion, the cooling working medium gradually changes into a liquid state, part of the liquid cooling working medium flows back to the first substrate from the first heat dissipation portion, and the other part of the liquid cooling working medium flows into the flow collection channel of the flow collection portion, then enters the reflux pipe from the flow collection portion, and then flows back to the first substrate through the reflux pipe. The first substrate, the first heat dissipation portion, the flow collection portion and the reflux pipe are in communication, which reduces the possibility of the liquid cooling working medium remaining in the first heat dissipation portion.

[0053] In an alternative embodiment, the confluence part comprises a first plate and a second plate, the edge of the first plate and the edge of the second plate are fixedly connected, the first plate is connected with the end of the first heat dissipation part away from the first substrate, the second plate is located on the side of the first plate away from the first heat dissipation part, the second plate is bulged towards the side away from the first plate, and the confluence channel is located between the first plate and the second plate; the second plate is provided with a plurality of concave structures, the plurality of concave structures are recessed into the confluence channel in the direction close to the first plate, and the plurality of concave structures are in abutment with the first plate.

[0054] The concave structures on the second plate are recessed into the confluence channel in the direction close to the first plate and are in abutment with the first plate, the concave structures can support the internal cavity (confluence channel) of the confluence part, reduce the possibility of the confluence channel being pressed and collapsed by external force, and make the structural strength of the confluence part higher.

[0055] In an alternative embodiment, the first gas-liquid channel is provided with a first evaporation zone, the first evaporation zone is connected with the inner wall surface of the first substrate on the side close to the first power device, the outer wall surface corresponding to the inner wall surface of the first substrate connected with the first evaporation zone is in contact with the first power device, the first gas-liquid channel comprises a first cavity and a second cavity located on both sides of the first evaporation zone in the vertical direction, and the first evaporation zone is provided with a plurality of first flow channels communicating the first cavity and the second cavity.

[0056] The first power device abuts against the region of the first substrate provided with the first evaporation zone, and the heat on the first power device is transmitted to the first evaporation zone through the first substrate. Since the first evaporation zone is provided with a plurality of first flow channels, the contact area of the first evaporation zone with the cooling working medium is larger, that is, the boiling nucleation points on the first evaporation zone are increased. The cooling working medium needs to flow between the first cavity and the second cavity through the first flow channels, that is, the cooling working medium flows from below the first evaporation zone to above the first evaporation zone through the first flow channels, and more boiling nucleation points are conducive to the change of the liquid cooling working medium into gas.

[0057] In an alternative embodiment, the two sides of the first evaporation zone are provided with second evaporation zones, the distribution directions of the two second evaporation zones are perpendicular to the vertical direction, the second evaporation zones are provided with a plurality of second flow channels communicating the first cavity and the second cavity, and the number of the second flow channels on each second evaporation zone is less than the number of the first flow channels.

[0058] The two second evaporation zones are respectively located on the two sides of the first power device, and the plurality of second flow channels on the second evaporation zones can increase the boiling nucleation points on the second evaporation zones, which is conducive to the change of the cooling working medium from liquid to gas when the cooling working medium flows through the second flow channels. Since the second evaporation zones are farther away from the first power device than the first evaporation zone, and the number of the second flow channels on each second evaporation zone is less than the number of the first flow channels, more cooling working medium can pass through the first evaporation zone. BRIEF DESCRIPTION OF DRAWINGS

[0059] Fig. 1 is a schematic diagram of the external structure of a power conversion device according to an embodiment of the present application;

[0060] Fig. 2 is a schematic diagram of the internal chamber of a power conversion device according to an embodiment of the present application;

[0061] Fig. 3 is a schematic diagram of the internal structure of a heat dissipation chamber of a power conversion device according to an embodiment of the present application;

[0062] Fig. 4 is a partial exploded view of a power conversion device according to an embodiment of the present application;

[0063] Fig. 5 is a schematic diagram of the internal structure of a heat sink according to an embodiment of the present application;

[0064] Fig. 6 is an enlarged view of A in Fig. 4;

[0065] Fig. 7 is a schematic diagram of the internal structure of another heat sink according to an embodiment of the present application;

[0066] Fig. 8 is a schematic diagram of the mounting method of a fin according to an embodiment of the present application;

[0067] Fig. 9 is a schematic diagram of the partial structure of a fin according to an embodiment of the present application;

[0068] Fig. 10 is a schematic diagram of the structure of a busbar according to an embodiment of the present application;

[0069] Fig. 11 is a schematic diagram of the structure of a first plate and a second plate according to an embodiment of the present application;

[0070] Fig. 12 is a schematic diagram of the structure of another busbar according to an embodiment of the present application;

[0071] Fig. 13 is a schematic diagram of the structure of a return pipe according to an embodiment of the present application;

[0072] Fig. 14 is a schematic diagram of the structure of a first evaporation zone according to an embodiment of the present application;

[0073] Fig. 15 is a schematic diagram of the structure of another first evaporation zone according to an embodiment of the present application;

[0074] Fig. 16 is a schematic diagram of the structure of a support group according to an embodiment of the present application;

[0075] Fig. 17 is a schematic diagram of the structure of a cover plate and a bottom plate according to an embodiment of the present application;

[0076] Fig. 18 is a schematic diagram of the structure of a threaded hole according to an embodiment of the present application;

[0077] Fig. 19 is a schematic diagram of the structure of another threaded hole according to an embodiment of the present application;

[0078] Fig. 20 is a schematic view of a structure of a threaded hole according to an embodiment of the present application;

[0079] Fig. 21 is a schematic view of an internal structure of a heat dissipation cavity of a second power conversion device according to an embodiment of the present application;

[0080] Fig. 22 is a schematic view of an internal structure of a heat dissipation cavity of a third power conversion device according to an embodiment of the present application;

[0081] Fig. 23 is a schematic view of an internal structure of a heat dissipation cavity of a fourth power conversion device according to an embodiment of the present application;

[0082] Fig. 24 is a partial exploded view of the fourth power conversion device according to an embodiment of the present application;

[0083] Fig. 25 is a schematic view of a structure of another heat sink according to an embodiment of the present application;

[0084] Fig. 26 is a schematic view of a structure of another heat sink according to an embodiment of the present application;

[0085] Fig. 27 is a schematic view of a structure of a first connecting pipe and a second connecting pipe according to an embodiment of the present application;

[0086] Fig. 28 is a schematic view of an internal structure of a heat dissipation cavity of a fifth power conversion device according to an embodiment of the present application;

[0087] Fig. 29 is a partial exploded view of the fifth power conversion device according to an embodiment of the present application;

[0088] Fig. 30 is a schematic view of an internal structure of a heat dissipation cavity of a sixth power conversion device according to an embodiment of the present application;

[0089] Fig. 31 is a schematic view of positions of a plurality of first heat exchangers according to an embodiment of the present application;

[0090] 100-power conversion device; 1-housing; 11-separator; 111-power cavity; 112-heat dissipation cavity; 113-opening; 114-mounting port; 115-through port; 12-protective cover; 121-heat dissipation hole; 1211-inlet hole; 1212-outlet hole; 2-circuit board; 21-first power device; 211-bolt; 2111-head; 2112-shaft; 22-through hole; 23-second power device; 24-inductor; 25-electronic device; 3-radiator; 31-first base plate; 310-first gas-liquid channel; 311-first wall surface; 312-second wall surface; 313-support; 3131-support group; 3132-flow equalization channel; 314-first evaporation zone; 3141-first flow channel; 3142-ridge; 315-second evaporation zone; 3151-second flow channel; 316-first cavity; 317-second cavity; 318-bottom plate; 3181-thread hole; 319-cover plate; 3191-ledge; 32-first heat dissipation part; 320-second gas-liquid channel; 321-first condensation pipe; 3211-sub channel; 33-accommodation space; 34-finned; 341-bent section; 342-ventilation channel; 35-converging part; 350-converging channel; 3501-first plate; 351-second plate; 3511-recessed structure; 352-converging pipe; 353-return pipe; 36-second base plate; 360-third gas-liquid channel; 37-second heat dissipation part; 370-fourth gas-liquid channel; 371-second condensation pipe; 4-first heat exchanger; 41-first flat heat dissipation pipe; 42-first heat dissipation fin; 43-heat conduction plate; 44-heat dissipation fin; 441-first heat dissipation fin; 442-second heat dissipation fin; 5-second heat exchanger; 51-first flat heat dissipation pipe; 22-first heat dissipation fin; 6-first connecting pipe; 61-heat exchange inlet; 7-second connecting pipe; 71-heat exchange outlet; 8-first fan; 9-second fan. DETAILED DESCRIPTION

[0091] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0092] In the present application, unless otherwise explicitly specified and limited, the orientation or position relationship indicated by the terms "upper", "lower", etc. can include but is not limited to the orientation defined by the relative placement of the components in the drawings, wherein these directional terms can be a relative concept, which are used for relative description and clarification, and can be changed accordingly according to the change of the placement of the components in the drawings, and cannot be understood as a limitation on the present application.

[0093] In the present application, the terms "first", "second", etc. are only used for descriptive purposes, and are used to distinguish one element from another, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", etc. can be explicitly or implicitly included one or more of the features.

[0094] In the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0095] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, when describing pipelines or channels, "connecting" and "connecting" used in the present application have the meaning of conducting. The specific meaning should be understood in combination with the context.

[0096] In addition, in the present application, the words "exemplary" or "for example" are used to represent an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. On the contrary, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific way.

[0097] In the drawings of the embodiments of the present application, the entity structure of components, assemblies, etc. is represented by guide lines; the hollow structure of openings, holes, spaces, cavities, etc. is represented by guide lines with arrows.

[0098] The embodiments of the present application provide a power conversion device 100, for example, the power conversion device 100 includes a photovoltaic inverter, in particular, a group string type photovoltaic inverter with very high power level, reaching 400 kilowatts and above. When the single-machine power of the photovoltaic inverter reaches 400 kilowatts or above, the traditional physical structure form of heat dissipation solution has been unable to meet the needs of heat dissipation of such high-power power devices, and a new, more powerful heat dissipation solution is needed to meet the new challenges. As the embodiments of the present application introduce two-phase heat dissipation technology into the photovoltaic inverter, through the gas-liquid transformation of the heat-conducting working medium inside and outside the power cavity, the heat of the power device of the super-large power photovoltaic inverter is effectively dissipated in time, so as to ensure the long-term stable operation of the power conversion device 100.

[0099] As shown in Fig. 1, the external structure of the power conversion device 100 is exemplarily shown, and Fig. 2 exemplarily shows the internal chamber of the power conversion device 100. As shown in Fig. 1 and Fig. 2, when the power conversion device 100 is a photovoltaic inverter, it is vertically installed, and various input interfaces are installed on the bottom of the power conversion device 100 in the vertical direction, including a large number of photovoltaic input terminals and communication ports, etc.

[0100] Referring to Fig. 1 and Fig. 2, the power conversion device 100 includes a housing 1, which includes a cabinet structure (for example, a cabinet), a box structure (for example, a box), etc., and the shape of the housing 1 is not specifically limited in the present application. The housing 1 includes a partition plate 11, for example, the partition plate 11 includes a side wall (or referred to as a side plate, a shell plate) of one side of the housing 1, that is, the partition plate 11 is a part of the housing 1. A sealed power cavity 111 is formed in the housing 1, and an open ventilation heat dissipation cavity 112 is formed outside the housing 1, and the partition plate 11 is located between the power cavity 111 and the heat dissipation cavity 112, that is, the power cavity 111 is an internal chamber of the housing 1, and the heat dissipation cavity 112 is located outside the housing 1.

[0101] The heat dissipation cavity 112 can be formed by providing a protective cover 12 outside the housing 1, for example, referring to Fig. 1 and Fig. 2, the power conversion device 100 further includes a protective cover 12, and the heat dissipation cavity 112 is formed in the protective cover 12, and the power cavity 111 and the heat dissipation cavity 112 are distributed along a first direction, and the first direction is perpendicular to the vertical direction, and the protective cover 12 is provided with a heat dissipation hole 121 which is in communication with the internal heat dissipation cavity 112. In some examples, the protective cover 12 has a hollow structure, and the heat dissipation hole 121 includes the hole in the hollow protective cover 12. In the examples of Fig. 1 and Fig. 2, the heat dissipation hole 121 is provided in a partial area of the protective cover 12, and in other examples, the heat dissipation hole 121 can be provided in the entire area of each wall of the protective cover 12, and the present application does not specifically limit this.

[0102] Referring to Fig. 2, the power conversion device 100 further includes a circuit board 2, for example, a printed circuit board (PCB). The circuit board 2 is arranged in the power cavity 111, and the circuit board 2 can be arranged in parallel with the partition plate 11. A plurality of devices are arranged on the circuit board 2, in order to protect the circuit board 2 and the devices thereon, the protection level of the power cavity 111 is higher than that of the heat dissipation cavity 112, for example, the ingress protection (IP) level of the power cavity 111 is higher than that of the heat dissipation cavity 112.

[0103] The devices disposed on the circuit board 2 include at least one of a chip, a resistor, a capacitor, a diode, and a transistor. A plurality of devices can be disposed on the same side of the circuit board 2, and a plurality of devices can also be partially disposed on the side of the circuit board 2 facing away from the partition plate 11. For example, a plurality of electronic devices 25 (including but not limited to capacitors, inductors, relays, etc.) are disposed on the side of the circuit board 2 facing away from the partition plate 11, and another part of the plurality of devices is disposed on the side of the circuit board 2 close to the partition plate 11.

[0104] In the present application, a plurality of devices are disposed on the sides of the circuit board 2. FIG. 3 exemplarily shows the internal structure of the power conversion device 100, and FIG. 4 exemplarily shows an exploded view of the partial structure of the power conversion device 100. Referring to FIGS. 3 and 4, the partition plate 11 is provided with an opening 113, which communicates the power cavity 111 and the heat dissipation cavity 112. The opening 113 includes a square opening or a circular opening.

[0105] The side of the circuit board 2 facing the opening 113 is provided with a first power device 21. The first power device 21 constitutes a power conversion circuit of the power conversion device 100 to perform power conversion on the direct current input to the power conversion device 100. For example, the first power device 21 includes a power module or a plurality of power switching tubes. In some examples, the first power device 21 includes devices on the circuit board 2 that generate more heat. The end of the first power device 21 connected to the circuit board 2 is located in the power cavity 111, and the end of the first power device 21 facing away from the circuit board 2 extends to the heat dissipation cavity 112. The first power device 21 and the plurality of other devices on the circuit board 2 are respectively mounted on the two opposite sides of the circuit board 2 and are separated by the circuit board 2, so as to prevent the heat of the first power device 21 from entering the power cavity 111 on the other side of the circuit board 2, thereby causing the temperature in the power cavity 111 to rise and causing thermal pollution to other devices that also need to be protected.

[0106] It can be seen that the heat dissipation scheme of the power conversion device 100 in the embodiment of the present application is based on hierarchical classification heat dissipation, that is, different heat dissipation modes and heat conduction paths are designed for the high-heat first power device 21, the low-heat electronic device 25 requiring high protection, and the high-heat inductor device to dissipate heat; and the core of the heat dissipation scheme is the two-phase enhanced heat dissipation mode to dissipate heat and protect the core device and the core heat source. For example, the first power device 21 is subjected to high-intensity internal and external two-phase conversion heat dissipation to ensure that the heat of the entire device is well solved, and various electronic components are also protected according to their characteristics.

[0107] Referring to FIG. 3 and FIG. 4, the power conversion device 100 further comprises a heat sink 3, the heat sink 3 is arranged in the heat dissipation cavity 112, the heat sink 3 comprises a first base plate 31 and a first heat dissipation part 32 in communication with the internal cavity, the first base plate 31 extends in the vertical direction and protrudes the first heat dissipation part 32, for example, the first base plate 31 protrudes towards the lower side of the first heat dissipation part 32, the first base plate 31 is arranged at the opening 113, the first power device 21 is located in the power cavity 111 and is in thermal contact with the first base plate 31, the first heat dissipation part 32 is arranged on the side of the first base plate 31 away from the partition plate 11.

[0108] FIG. 5 shows the structure inside the heat sink 3, the first base plate 31 is provided with a first gas-liquid passage 310, the first heat dissipation part 32 is provided with a second gas-liquid passage 320 in communication with the first gas-liquid passage 310, the internal cavity of the first base plate 31 is provided with a cooling working medium for gas-liquid conversion. Wherein, the cooling working medium comprises water or other refrigerants capable of gas-liquid conversion.

[0109] When the first power device 21 generates heat, the heat on the first power device 21 will be transferred to the first base plate 31, and heat the cooling working medium in the first base plate 31, when the liquid cooling working medium is heated and warmed up, at least part of the cooling working medium will become gaseous, the gaseous cooling working medium flows into the first heat dissipation part 32, that is, from the first gas-liquid passage 310 into the second gas-liquid passage 320, the heat dissipation hole 121 (auxiliary reference to FIG. 2) of the shell 1 in communication with the heat dissipation cavity 112 facilitates the cooling working medium in the first heat dissipation part 32 to exchange heat with the outside, so that the gaseous cooling working medium is condensed in the first heat dissipation part 32 and gradually changes back to liquid, and then flows back to the first gas-liquid passage 310 of the first base plate 31 from the second gas-liquid passage 320, so as to circulate and continuously dissipate heat for the first power device 21. By targeted heat dissipation of the first power device 21, the power conversion device 100 can be stably operated.

[0110] In order to effectively dissipate heat, the heat dissipation cavity 112 is in communication with the outside through the heat dissipation hole 121, and the partition plate 11 can reduce the possibility of impurities in the heat dissipation cavity 112 or the outside entering the power cavity 111. And, the first base plate 31 is arranged at the opening 113, which not only facilitates the contact between the first base plate 31 and the first power device 21, but also can shield the opening 113, further reducing the possibility of mutual interference between the heat dissipation cavity 112 and the power cavity 111, so that the circuit board 2 can be arranged in the power cavity 111 with relatively strong protection capability, on the basis of dissipating heat for the first power device 21, the safety of other devices (for example, multiple electronic devices 25) is guaranteed, and the possibility of failure of the power conversion device 100 is reduced.

[0111] Referring to FIG. 3 and FIG. 4, in an example, the edge portion of the first substrate 31 is directly opposite the plate surface of the partition plate 11, and the first substrate 31 blocks the opening 113. It should be noted that the portion of the first substrate 31 that is directly opposite the plate surface of the partition plate 11 means that the first substrate 31 and the partition plate 11 have an overlap in the first direction. In the case of having an overlap, the first substrate 31 can abut on the partition plate 11, or even if the first substrate 31 does not abut on the partition plate 11, the overlap between the first substrate 31 and the partition plate 11 can better shield the opening 113, reduce the possibility of the gas in the heat dissipation cavity 112 entering the power cavity 111 through the opening 113, and reduce the possibility of external impurities affecting the operation of the circuit board 2 and the devices thereon. This makes the power cavity 111 and the heat dissipation cavity 112 more independent of each other, and forms a high-protection cavity (power cavity 111) in the power conversion device 100 to accommodate the circuit board 2, which is conducive to the normal operation of the power conversion device 100.

[0112] In order to better dissipate heat, the first power device 21 is at least partially located below the first heat dissipation portion 32. In the example shown in FIG. 5, the first power device 21 extends partially below the first heat dissipation portion 32 and is in thermal contact with the portion of the first substrate 31 that protrudes below the first heat dissipation portion 32. Another portion of the first power device 21 is directly opposite the first heat dissipation portion 32 in the first direction, so that the overlap area of the first heat dissipation portion 32 and the first power device 21 in the first direction is small. The first heat dissipation portion 32 has more area to exchange heat with the air in the heat dissipation cavity 112, which is conducive to improving the heat dissipation effect of the heat sink 3.

[0113] In other examples, the first power device 21 is completely located below the first heat dissipation portion 32 and is in thermal contact with the portion of the first substrate 31 that protrudes below the first heat dissipation portion 32. That is, the first power device 21 and the first heat dissipation portion 32 are respectively located on two sides of the first substrate 31, and the first power device 21 and the first heat dissipation portion 32 have a spacing in the vertical direction, or in other words, the first power device 21 and the first heat dissipation portion 32 do not overlap in the first direction.

[0114] Regarding the structure of the first substrate 31, in an example provided in the present application, referring to FIG. 4 and FIG. 5, the first substrate 31 is a square plate structure. In other examples, the first substrate 31 can also be a circular disc or other irregular-shaped plates without obvious shape, which is not limited in the present application.

[0115] The first heat dissipation part 32 has a structure capable of playing a condensing role. For example, the first heat dissipation part 32 is a micro-channel condenser provided with heat dissipation fins. FIG. 6 is an enlarged view of position A in FIG. 4. Referring to FIGS. 5 and 6, the first heat dissipation part 32 includes a plurality of first condensing pipes 321 arranged at intervals in a second direction. The first direction, the second direction, and the vertical direction are perpendicular to each other. In the example shown in FIG. 5, each first condensing pipe 321 can be a micro-channel flat pipe. A plurality of sub-channels 3211 (i.e., micro-channels in the micro-channel flat pipe) in each first condensing pipe 321 are arranged in the vertical direction, and each sub-channel 3211 extends in the first direction.

[0116] It should be noted that the sub-channels 3211 described above are channels capable of allowing the cooling medium to flow. The size and structure of the sub-channels 3211 are not limited in the present application. The plurality of sub-channels 3211 in each first condensing pipe 321 form an internal chamber of the first condensing pipe 321, and the internal chambers of the plurality of first condensing pipes 321 form the second gas-liquid passage 320 of the first heat dissipation part 32. In other examples, the first condensing pipe 321 can not be a plate-shaped pipe with multiple layers of channels arranged inside, but can be a plate-shaped pipe with a complete chamber inside, or a pipe with a zigzag arrangement, which is not limited in the present application.

[0117] In one example, referring to FIG. 6, a plurality of fins 34 are arranged between adjacent two first condensing pipes 321. In other examples, the fins 34 can also not be arranged.

[0118] After the cooling medium in the first heat dissipation part 32 becomes liquid, it needs to flow back to the first base plate 31. In order to facilitate the cooling medium in the first heat dissipation part 32 to flow back to the first base plate 31, in some examples, referring to FIG. 7, the first heat dissipation part 32 can be arranged obliquely. For example, the included angle a between the first gas-liquid passage 310 and the second gas-liquid passage 320 is greater than 90 degrees and less than 180 degrees, where the included angle a includes 95 degrees, 120 degrees, 150 degrees, 160 degrees, or 170 degrees, or the included angle a is within a range between these angles. For another example, the included angle a between the first gas-liquid passage 310 and the second gas-liquid passage 320 is greater than 90 degrees and less than or equal to 160 degrees, where the included angle a includes 110 degrees, 130 degrees, 140 degrees, 160 degrees, etc., or the included angle a is within a range between these angles. By forming a specific angle between the first gas-liquid passage 310 and the second gas-liquid passage 320, the cooling medium can be smoothly returned to the first base plate 31 under the action of gravity to a position close to the first power device 21 in heat conduction contact.

[0119] When the first heat dissipation part 32 needs to be arranged obliquely, in the example where the first heat dissipation part 32 includes a plurality of first condensing pipes 321 (for example, micro-channel flat tube structure), the first condensing pipe 321 is a flat tube similar to a parallelogram structure, and each sub-channel 3211 is obliquely inclined from the first base plate 31 to the upper side in the first direction, so that the liquid in the first heat dissipation part 32 flows back to the first base plate 31, reducing the possibility of liquid cooling medium staying in the first heat dissipation part 32.

[0120] In the example shown in FIG. 5, the included angle a between the first gas-liquid channel 310 and the second gas-liquid channel 320 is also 90 degrees, that is, the first gas-liquid channel 310 and the second gas-liquid channel 320 are perpendicular to each other.

[0121] In some examples, when a plurality of fins 34 are arranged between two adjacent first condensing pipes 321, the installation mode of the fins 34 is adjusted to enable the wind to better dissipate heat for the fins 34. Taking the oblique arrangement of the first heat dissipation part 32 as an example, the installation mode of the fins 34 is described, and FIG. 8 exemplarily shows an installation mode of the fins 34, and FIG. 9 shows the partial structure of the fins 34 in FIG. 8. Referring to FIG. 9, the plurality of fins 34 between the two adjacent first condensing pipes 321 are arranged in the first direction, and the two adjacent fins 34 are integrally connected by the bending section 341 between the two fins 34, so that the plurality of fins 34 and the plurality of bending sections between the two adjacent first condensing pipes 321 form a corrugated plate structure (the two adjacent fins 34 can also not be connected, for example, the scheme of the fins 34 in FIG. 6). Among them, the two adjacent fins 34 have a ventilation channel 342 parallel to the ventilation direction, for example, referring to FIG. 8, the power conversion device 100 further includes a first fan 8 (the position of the first fan 8 can also be assisted by referring to FIGS. 3 and 4), and the first fan 8 can be arranged below the ventilation channel 342. Under the action of the first fan 8, the wind passes through the first heat dissipation part 32 in the vertical direction (the arrow X1 represents the flow direction of the wind). In this case, the ventilation channel 342 extends in the vertical direction (the dashed line L1 is the extension direction of the ventilation channel 342), or in other words, the extension direction of the ventilation channel 342 is parallel to the plate surface of the base plate 31 (the dashed line L1 is parallel to the dashed line L2). Through this design mode, the resistance of the wind passing through the first heat dissipation part 32 can be reduced, and in addition, the possibility of the ventilation channel 342 being blocked by dust can be reduced, thereby improving the heat dissipation effect of the heat dissipation device 3.

[0122] In addition, in order to facilitate the return of the cooling medium, the heat sink 3 can further include a flow collecting portion 35, the positions of the flow collecting portion 35 in two examples are shown in FIG. 5 and FIG. 7 respectively, the flow collecting portion 35 is arranged on the side of the first heat dissipation portion 32 away from the first base plate 31, a flow collecting channel 350 is arranged in the flow collecting portion 35, and the flow collecting channel 350 of the flow collecting portion 35 is in communication with the second gas-liquid channel 320 of the first heat dissipation portion 32. In the case where the first heat dissipation portion 32 includes a plurality of first condensing pipes 321, and each first condensing pipe 321 includes a plurality of sub-channels 3211 (auxiliary reference to the description of the same above), the flow collecting channel 350 is in communication with different sub-channels 3211 in the second gas-liquid channel 320, so that the different sub-channels 3211 in the second gas-liquid channel 320 are in communication with each other through the flow collecting channel 350. After the cooling medium is cooled and condensed in the first heat dissipation portion 32, the cooling medium gradually changes to a liquid state, a part of the liquid cooling medium directly flows back to the first base plate 31 from the first heat dissipation portion 32 without entering the flow collecting portion 35, and another part of the liquid cooling medium flows into the flow collecting channel 350 of the flow collecting portion 35, then flows downward from the flow collecting channel 350, and then flows back to the first base plate 31 through the bottom of the second gas-liquid channel 320, which is conducive to the condensation and return of the cooling medium.

[0123] FIG. 10 exemplarily shows a structure of a flow collecting portion 35, the flow collecting portion 35 can include a first plate 3501 and a second plate 351, FIG. 11 exemplarily shows the structure of the first plate 3501 and the second plate 351, referring to FIG. 10 and FIG. 11, the edge of the first plate 3501 is fixedly connected (for example, welded) with the edge of the second plate 351, wherein the first plate 3501 (hidden by the second plate 351 in FIG. 10, located behind the second plate 351) is connected with the first heat dissipation portion 32, the second plate 351 is located on the side of the first plate 3501 away from the first heat dissipation portion 32, and the second plate 351 bulges towards the side away from the first plate 3501, so that the first plate 3501 and the second plate 351 enclose the flow collecting channel 350. And a plurality of concave structures 3511 can be arranged on the second plate 351, the concave structures 3511 are recessed into the flow collecting channel 350 towards the direction close to the first plate 3501, and abut against the first plate 3501 to play a supporting role, thereby reducing the possibility of the internal cavity of the flow collecting portion 35 being pressed and collapsed.

[0124] FIG. 12 exemplarily shows another structure of a flow collecting portion 35, in the example shown in FIG. 12, the first heat dissipation portion 32 includes a plurality of first condensing pipes 321, and the flow collecting portion 35 includes a plurality of flow collecting pipes 352, each flow collecting pipe 352 is in communication with different sub-channels 3211 of one first condensing pipe 321 (the structure of the sub-channels 3211 is auxiliary reference to FIG. 5 and FIG. 7), and the internal spaces of all the flow collecting pipes 352 constitute the flow collecting channel 350. In other examples, each flow collecting pipe 352 is a solid pipe.

[0125] Fig. 13 shows another example of the structure of the converging portion 35. Referring to Fig. 13, the converging portion 35 is configured as a hollow plate or a hollow box structure. In this example, a support structure can also be provided in the converging channel 350 of the converging portion 35, which plays the same role as the inner recess structure 3511 in Fig. 10. The difference between the support structure in Fig. 13 and the inner recess structure 3511 in Fig. 10 is that the inner recess structure 3511 in Fig. 10 is formed by local pressure or other processing methods directly on the second plate 351 during processing, while the support structure in Fig. 13 is provided separately (e.g., welded later) to play a supporting role. Fig. 13 shows another example of the structure without the support structure.

[0126] In some examples, the heat sink 3 further includes a return pipe 353. For example, referring to the converging portion 35 shown in Fig. 13, the return pipe 353 is arranged below the first heat dissipation portion 32. One end of the return pipe 353 communicates with the first gas-liquid channel 310 in the first base plate 31, and the other end communicates with the converging channel 350 in the converging portion 35. The positions of the first gas-liquid channel 310 and the converging channel 350 can be referred to Fig. 5 or Fig. 7. The return pipe 353 can be provided with a plurality of return pipes and arranged at intervals in the second direction.

[0127] In the above examples, after the cooling medium is cooled and condensed in the first heat dissipation portion 32, the cooling medium gradually changes to a liquid state. Part of the liquid cooling medium flows back to the first base plate 31 from the second gas-liquid channel 320 of the first heat dissipation portion 32, and the other part of the liquid cooling medium flows into the converging portion 35, then enters the return pipe 353 from the converging channel 350, and finally flows back to the first base plate 31 through the return pipe 353. The first base plate 31, the first heat dissipation portion 32, the converging portion 35, and the return pipe 353 are in communication with each other, which reduces the possibility of the liquid cooling medium remaining in the first heat dissipation portion 32.

[0128] In addition, in order to facilitate evaporation, the structure of the first base plate 31 can also be improved. For example, Fig. 14 shows another example of the structure of the first base plate 31. Referring to Fig. 14, the first gas-liquid channel 310 of the first base plate 31 is provided with a first evaporation zone 314, which is arranged opposite the first power device 21 in the first direction (the position of the first power device 21 can be referred to Fig. 5 or Fig. 7). The side of the first evaporation zone 314 facing the first power device 21 is connected to the inner wall of the first base plate 31. The outer wall of the first base plate 31 corresponding to the inner wall connected to the first evaporation zone 314 is in contact with the first power device 21. That is, the area of the first base plate 31 provided with the first evaporation zone 314 is the area of the first base plate 31 in contact with the first power device 21.

[0129] The first gas-liquid passage 310 inside the first substrate 31 includes a first chamber 316 and a second chamber 317 located on both sides of the first evaporation zone 314 in the vertical direction, and the first evaporation zone 314 is provided with a plurality of first flow channels 3141 that communicate the first chamber 316 and the second chamber 317. It can be understood that the first flow channels 3141 also belong to the first gas-liquid passage 310. In the example shown in FIG. 14, the first flow channels 3141 can be grooves opened on the first evaporation zone 314, and each groove extends in the vertical direction, so that each first flow channel 3141 extends in the vertical direction to communicate the vertically distributed first chamber 316 and second chamber 317, and a plurality of first flow channels 3141 are distributed in the second direction.

[0130] Since the first power device 21 abuts against the region of the first substrate 31 where the first evaporation zone 314 is provided, the heat on the first power device 21 can be transmitted to the first evaporation zone 314 through the first substrate 31. The first evaporation zone 314 is provided with a plurality of first flow channels 3141, which can increase the surface area of the first evaporation zone 314, so that the contact area of the first evaporation zone 314 with the cooling working medium is larger, that is, the boiling nucleation points on the first evaporation zone 314 are increased. The cooling working medium needs to flow between the first chamber 316 and the second chamber 317 through the first flow channels 3141, that is, the cooling working medium flows from below the first evaporation zone 314 into above the first evaporation zone 314 through the first flow channels 3141, and more boiling nucleation points are conducive to the change of the liquid cooling working medium into the gaseous state.

[0131] In the example shown in FIG. 14, the first evaporation zone 314 is formed by providing a plurality of first flow channels 3141 (groove-like structures) on the raised structure inside the first substrate 31, so that the first evaporation zone 314 is similar to a dense tooth structure. Among them, the inner wall surface of the first gas-liquid passage 310 surrounded by the first substrate 31 includes a first wall surface 311 and a second wall surface 312, and FIG. 14 only exemplarily shows the first wall surface 311 (the wall surface close to the first power device 21), and the second wall surface 312 can be assisted with reference to FIG. 5. The first wall surface 311 and the second wall surface 312 are oppositely arranged in the thickness direction (the first direction) of the first substrate 31, and the first evaporation zone 314 can be integrally connected with the first wall surface 311, so that the heat of the first power device 21 can be quickly transmitted to the first evaporation zone 314. In other examples, the first evaporation zone 314 can include a plurality of heat-conducting fins (for example, fins), and the plurality of heat-conducting fins are distributed in the second direction, and the first flow channels 3141 are formed between adjacent two heat-conducting fins.

[0132] In other examples, referring to FIG. 15, the first evaporation zone 314 is shown in another example structure, which includes a plurality of matrix-arranged protrusions 3142, any one of which forms a channel connecting the first chamber 316 and the second chamber 317, which is a first flow channel 3141. In this example, the first evaporation zone 314 can also be integrally connected with the first wall 311.

[0133] In other examples, the first evaporation zone 314 is a corrugated plate with multiple bends. In this example, the first evaporation zone 314 is a separate structure, which is installed on the first base plate 31 and then connected with the inner wall of the first base plate 31 through later welding (or other connection methods).

[0134] In some examples, referring to FIGS. 14 and 15, the first evaporation zone 314 is provided with a second evaporation zone 315 on each side, and the distribution direction (second direction) of the two second evaporation zones 315 is perpendicular to the vertical direction. The second evaporation zone 315 is provided with a plurality of second flow channels 3151 connecting the first chamber 316 and the second chamber 317. It can be understood that the second flow channels 3151 also belong to the first gas-liquid channel 310. The second evaporation zone 315 is provided with the second flow channels 3151, which can increase the surface area of the second evaporation zone 315 and increase the boiling nucleation points thereon, which is conducive to the change of the cooling medium from liquid to gas when the cooling medium flows through the second flow channels 3151.

[0135] The second evaporation zone 315 is farther away from the first power device 21, and the first evaporation zone 314 is closer to the first power device 21, which can make the number of second flow channels 3151 on each second evaporation zone 315 less than the number of first flow channels 3141 (the first flow channels 3141 are more dense), so that more cooling medium passes through the first evaporation zone 314, which is conducive to the cooling medium absorbing the heat of the first power device 21. The liquid cooling medium in the second chamber 317 absorbs the heat of the first power device 21 and becomes gaseous, enters the first chamber 316 through the first flow channel 3141, and the cooled and liquefied cooling medium can flow back to the second chamber 317 through the second flow channel 3151.

[0136] As the first gas-liquid passage 310 is arranged in the first substrate 31, in order to reduce the possibility of deformation of the first substrate 31, in some examples, referring to FIG. 14 and FIG. 15, the inner wall surface of the first substrate 31 surrounding the first gas-liquid passage 310 includes a first wall surface 311 and a second wall surface 312, wherein FIG. 14 and FIG. 15 only exemplarily show the first wall surface 311 (the wall surface close to the first power device 21), and the second wall surface 312 can be supplemented with reference to FIG. 5. The first wall surface 311 and the second wall surface 312 are oppositely arranged in the thickness direction (the first direction) of the first substrate 31, and a plurality of supports 313 are arranged between the first wall surface 311 and the second wall surface 312. Each support 313 is connected or abuts to the first wall surface 311 at one end and connected or abuts to the second wall surface 312 at the other end. For example, the two ends of each support 313 are connected to the first wall surface 311 and the second wall surface 312, respectively.

[0137] In the two examples shown in FIG. 14 and FIG. 15, the space of the first chamber 316 is large, and a plurality of supports 313 can be arranged in the first chamber 316. In other examples, for example, in examples without the first evaporation zone 314 and the second evaporation zone 315, the supports 313 can be arranged at any suitable position to support the first substrate 31.

[0138] In the two examples shown in FIG. 14 and FIG. 15, the space of the first chamber 316 is large, and a plurality of supports 313 can be arranged in the first chamber 316. In other examples, for example, in examples without the first evaporation zone 314 and the second evaporation zone 315, the supports 313 can be arranged at any suitable position to support the first substrate 31.

[0139] In some examples, the plurality of supports 313 are divided into a plurality of rows of support groups 3131 arranged along the vertical direction. FIG. 16 schematically shows a structure of a support group 3131. Referring to FIG. 16, each row of support groups 3131 includes a plurality of supports 313 arranged along the second direction. Adjacent two rows of support groups 3131 form a flow uniformization channel 3132 for the flow of the cooling medium, where the flow uniformization channel 3132 extends along the second direction, and the flow uniformization channel 3132 is in communication with the second gas-liquid channel 320 (see FIG. 7 for the second gas-liquid channel 320), so that the cooling medium in the flow uniformization channel 3132 can flow to multiple regions of the second gas-liquid channel 320 along the second direction. For example, when the first heat dissipation part 32 includes a plurality of first condenser pipes 321 arranged along the second direction (for example, the dashed line box marked with “321” represents the installation position of one of the first condenser pipes 321), the flow uniformization channel 3132 is in communication with the plurality of first condenser pipes 321, so that the gaseous cooling medium can enter the plurality of first condenser pipes 321 to be cooled, reducing the possibility of the cooling medium being concentrated in an individual first condenser pipe 321.

[0140] In order to facilitate the production of the first substrate 31, the first substrate 31 can be divided into multiple parts for separate production and then assembled together. In some examples, the first substrate 31 includes a bottom plate 318 and a cover plate 319 arranged along the first direction. FIG. 17 schematically shows a structure of the bottom plate 318 and the cover plate 319. Referring to FIG. 17, the bottom plate 318 is connected to the first power device 21, and the cover plate 319 is located on the side of the bottom plate 318 away from the first power device 21. The edge of the cover plate 319 is fixedly connected to the edge of the bottom plate 318, and the cover plate 319 is bulged towards the side away from the bottom plate 318. The first gas-liquid channel 310 is located between the bottom plate 318 and the cover plate 319. One end of each support 313 is integrally connected to the bottom plate 318, and the other end is connected to or abuts against the cover plate 319.

[0141] In addition, referring to FIG. 16, on the bottom plate 318, the upward surfaces of the plurality of supports 313 in each row of support groups 3131 are flush (for example, the upward surfaces of the plurality of supports 313 in one of the rows of support groups 3131 are all parallel to the dashed line L3 along the vertical direction), the downward surfaces of the plurality of supports 313 in each row of support groups 3131 are flush (for example, the downward surfaces of the plurality of supports 313 in one of the rows of support groups 3131 are all parallel to the dashed line L4 along the vertical direction), and the upward surface and the downward surface of each support 313 are parallel along the vertical direction. In this way, the bottom plate 318 and the plurality of support groups 3131 thereon can be produced by extrusion molding, and then each support group 3131 can be separated into a plurality of supports 313 by turning (or other processing methods), which is conducive to improving the production and processing efficiency of the first substrate 31.

[0142] In addition, referring to FIG. 16 and FIG. 17, in the case where the first evaporation zone 314 and the second evaporation zone 315 are arranged in the first gas-liquid passage 310, the first evaporation zone 314 and the second evaporation zone 315 can also be integrally connected with the bottom plate 318. In some examples, the surface of the first evaporation zone 314 facing the first chamber 316 (the surface facing upward in the vertical direction) is flush with the surface of each second evaporation zone 315 facing the first chamber 316 (the surface facing upward in the vertical direction) (for example, both are parallel to the dashed line L5), and the surface of the first evaporation zone facing the second chamber 317 (the surface facing downward in the vertical direction) is flush with the surface of each second evaporation zone 315 facing the second chamber 317 (the surface facing downward in the vertical direction) (for example, both are parallel to the dashed line L6). In this way, the first evaporation zone 314 and the second evaporation zone 315 can also be formed on the bottom plate 318 by extrusion molding, and then the first flow channel 3141 is machined on the first evaporation zone 314 and the second flow channel 3151 is machined on the second evaporation zone 315 by turning (or other machining methods).

[0143] In order to better transfer the heat on the first power device 21 to the first base plate 31, the first power device 21 can be fixedly connected with the first base plate 31, so that the first power device 21 is in full contact with the first base plate 31, reducing the possibility of gaps between the contact surfaces of the first power device 21 and the first base plate 31. For example, FIG. 18 exemplarily shows a fixed connection mode.

[0144] Referring to FIG. 18, the first power device 21 can be fixedly connected with the first base plate 31 by a bolt 211. The circuit board 2 is provided with a through hole 22 for the head 2111 of the bolt 211 to pass through. The shank 2112 of the bolt 211 passes through the first power device 21 and is threadedly connected with the first base plate 31 (the first base plate 31 is provided with a threaded hole 3181 for threadedly connecting the bolt 211). The head 2111 of the bolt 211 abuts against the surface of the first power device 21 away from the first base plate 31, so that the first power device 21 can be tightly attached to the first base plate 31, and the heat dissipation effect of the first power device 21 is better. The bolt 211 can be provided with a plurality of corresponding through holes 22.

[0145] In the example shown in FIG. 18, the shank 2112 of the bolt 211 does not extend into or through the first gas-liquid passage 310. In addition, the head 2111 of the bolt 211 abuts against the first power device 21 rather than the circuit board 2, reducing the possibility of damaging the circuit board 2 when the bolt 211 is installed and fixed, and reducing the impact on the circuit board 2 when the first power device 21 and the first base plate 31 are connected.

[0146] Referring to FIG. 18, it can be understood that the threaded hole 3181 for the bolt 211 to be screwed into is a blind hole, and the threaded hole 3181 is formed on the surface of the first substrate 31 facing the first power device 21. For example, in the case where the first substrate 31 includes a bottom plate 318 and a cover plate 319 (see FIG. 17 for auxiliary reference), the threaded hole 3181 is formed on the surface of the bottom plate 318 facing away from the cover plate 319. In addition, FIG. 19 exemplarily shows another structure of the threaded hole 3181. Referring to FIG. 19, the first substrate 31 includes a bottom plate 318 and a cover plate 319, the cover plate 319 is provided with a boss 3191, the boss 3191 is internally provided with the threaded hole 3181, the boss 3191 extends towards the first power device 21 and penetrates through the bottom plate 318, so that the threaded hole 3181 is exposed outside, and the bolt 211 penetrates through the first power device 21 and is screwed into the threaded hole 3181 in the boss 3191. If the threaded hole 3181 in FIG. 19 is adopted, since the boss 3191 needs to penetrate through the bottom plate 318, the boss 3191 needs to be welded and sealed with the bottom plate 318 (for example, welding is needed at the position of the arrow X2), so as to reduce the possibility of leakage of the cooling working medium in the first gas-liquid channel 310. However, the threaded hole 3181 in FIGS. 17 and 18 is arranged in the form of a blind hole on the surface of the first substrate 31 facing the first power device 21, which can reduce the circumferential sealing weld of the bolt 211.

[0147] In some examples, referring to FIGS. 18 and 19, the first substrate 31 extends in the vertical direction and protrudes the first heat dissipation part 32 (protrudes to the lower side of the first heat dissipation part 32), the first power device 21 is in thermal contact with the part of the first substrate 31 protruding the first heat dissipation part 32, and a part of the first power device 21 extends to the lower side of the first heat dissipation part 32, and another part of the first power device 21 is directly opposite the first heat dissipation part 32 in the first direction. That is, the first heat dissipation part 32 and the first power device 21 have an overlapping area in the first direction, so that a part of the bolts 211 is directly opposite the first heat dissipation part 32 in the first direction, for example, the bolts 211 circled by the dashed line in FIGS. 18 and 19 are directly opposite the first heat dissipation part 32 in the first direction. In some examples, the positions of such bolts 211 and corresponding threaded holes 3181 can be adjusted to reduce the thickness of the first substrate 31. For example, FIG. 20 exemplarily shows the structure of such threaded holes 3181. Referring to FIG. 20, the first heat dissipation part 32 includes a plurality of first condenser pipes 321 spaced apart in the second direction, each first condenser pipe 321 penetrates the side wall of the first substrate 31 away from the first power device 21 and extends into the first gas-liquid passage 310. If the area of the first substrate 31 where the threaded hole 3181 is arranged protrudes to the first gas-liquid passage 310 on the side away from the first power device 21 (forms a boss protruding into the first gas-liquid passage 310), the position of the threaded hole 3181 (that is, the position of the bolt 211) can be directly opposite the area between the adjacent two first condenser pipes 321 (for example, the area where the fins 34 are located) in the first direction. In this way, the parts of the first condenser pipes 321 extending into the first gas-liquid passage 310 and the bolts 211 are distributed in a staggered manner, ensuring the smooth flow of the cooling medium in the first gas-liquid passage 310 while reducing the thickness of the first substrate 31.

[0148] Since the circuit board 2 is arranged in the power cavity 111, when the power conversion device 100 is in operation, the circuit board 2 and the devices thereon generate a large amount of heat, and the temperature in the power cavity 111 is relatively high. Therefore, it is necessary to dissipate heat from the power cavity 111, or in other words, to dissipate heat from the circuit board 2 and the devices thereon (for example, the electronic device 25 in the example shown in FIG. 2). Referring back to FIGS. 3 and 4, the power conversion device 100 can further include a first heat exchanger 4 for transferring heat in the power cavity 111 to the heat dissipation cavity 112 to dissipate heat from the electronic device 25.

[0149] In one example, the first heat exchanger 4 is arranged in the heat dissipation cavity 112, and a heat exchange channel in the first heat exchanger 4 is in communication with the power cavity 111. The first heat exchanger 4 has a first heat exchange channel (not shown in the figure as it is located in the first heat exchanger 4) formed therein, the first heat exchange channel is isolated from the heat dissipation cavity 112, and the first heat exchange channel has an inlet and an outlet (both are blocked and thus not shown in the figure) arranged on the first heat exchanger 4, and both the inlet and the outlet of the first heat exchange channel are in communication with the power cavity 111. For example, the inlet of the first heat exchange channel and the outlet of the first heat exchange channel are respectively in communication with the corresponding mounting ports 114 on the partition plate 11, so as to realize the communication between the first heat exchange channel inside the first heat exchanger 4 and the power cavity 111.

[0150] The arrangement of the first heat exchanger 4 can make the hot air in the power cavity 111 enter the first heat exchange channel of the first heat exchanger 4, and then exchange heat with the air in the heat dissipation cavity 112 in the first heat exchanger 4. The heat dissipation holes 121 of the heat dissipation device 3 are in communication with the outside, so that the air in the heat dissipation cavity 112 exchanges heat with the outside. In this way, the first heat exchanger 4 can efficiently dissipate heat in the heat dissipation cavity 112, and the temperature in the power cavity 111 is reduced, so that the power conversion device 100 can stably operate.

[0151] In one example, the first heat exchanger 4 includes a fin heat exchanger, for example, the first heat exchanger 4 includes a plurality of first flat heat dissipation pipes 41 and a plurality of first heat dissipation fins 42 (for example, a structure similar to fins), the plurality of first flat heat dissipation pipes 41 are spaced apart along the first direction, and a plurality of first heat dissipation fins 42 are arranged between adjacent two first flat heat dissipation pipes 41, and the internal space of the plurality of first flat heat dissipation pipes 41 constitutes the first heat exchange channel of the first heat exchanger 4. In other examples, the first heat exchange channel in the first heat exchanger 4 includes a channel similar to "S" type or a channel similar to a snake shape.

[0152] Referring to FIGS. 3 and 4, the first heat exchanger 4 is at least partially located between the portion of the first base plate 31 protruding the first heat dissipation portion 32 and the first heat dissipation portion 32, or in other words, the portion of the first base plate 31 protruding below the first heat dissipation portion 32 and the first heat dissipation portion 32 form a containing space 33, and the first heat exchanger 4 is at least partially arranged in the containing space 33. For example, the first heat exchanger 4 is located on the side of the first base plate 31 away from the partition plate 11, and the first heat exchanger 4 is located below the first heat dissipation portion 32. Arranging the first heat exchanger 4 in the containing space 33 makes the first heat exchanger 4 cross the first base plate 31 and overlap with the portion of the first base plate 31 protruding the first heat dissipation portion 32 in the first direction, which can make the heat dissipation device 3 and the first heat exchanger 4 more compact, and reduce the space occupation of the heat dissipation cavity 112.

[0153] In some other examples, referring to Fig. 21, the Fig. 21 exemplarily shows another setting position of the first heat exchanger 4, the first heat exchanger 4 is located in the power cavity 111, the first heat exchange channel in the first heat exchanger 4 is isolated from the power cavity 111, the first heat exchange channel has an inlet and an outlet arranged on the first heat exchanger 4, the inlet and the outlet of the first heat exchange channel are respectively communicated with the heat dissipation cavity 112 through the corresponding installation openings 114 on the partition plate 11.

[0154] Through the above design, the air in the heat dissipation cavity 112 can enter the first heat exchange channel of the first heat exchanger 4, and then exchange heat with the hot air in the power cavity 111 through the first heat exchanger 4, and the heat dissipation cavity 112 is open to ventilation. In this way, the external air can continuously enter the first heat exchange channel of the first heat exchanger 4, thereby reducing the temperature in the power cavity 111, so that the power conversion device 100 can stably operate.

[0155] In some other examples, referring to Fig. 22, the Fig. 22 exemplarily shows another setting position of the first heat exchanger 4, the first heat exchanger 4 is located in the heat dissipation cavity 112, the first heat exchanger 4 includes a plurality of heat dissipation fins 44 and a heat conduction plate 43 connected with each other, the heat conduction plate 43 is thermally adhered to the first base plate 31, the plurality of heat dissipation fins 44 are fixed to one side of the heat conduction plate 43 away from the first base plate 31 along the second direction, the heat dissipation cavity 112 is provided with a first fan 8, and the first fan 8 is used to generate airflow through the heat dissipation fins 44.

[0156] The temperature of the electronic device 25 rises, which causes the temperature of the power cavity 111 to rise, and the heat in the power cavity 111 is transmitted to the heat conduction plate 43 through the first base plate 31, and then the heat conduction plate 43 transmits the heat to the heat dissipation fins 44. The first fan 8 blows air towards the heat dissipation fins 44, and the heat dissipation cavity 112 is open to ventilation, so that the heat on the heat dissipation fins 44 can be blown to the outside of the heat dissipation cavity 112 (or the outside of the protective cover 12), that is, to the outside, and the first fan 8 rotates to realize heat dissipation of the heat dissipation fins 44, that is, to indirectly dissipate heat for the electronic device 25 in the power cavity 111.

[0157] In the example in which the first substrate 31 protrudes downwardly toward the first heat dissipation portion 32, referring to FIG. 22, the heat conduction plate 43 is heat-conductively attached to the portion of the first substrate 31 protruding toward the first heat dissipation portion 32, and the heat dissipation fins 44 are located below the first heat dissipation portion 32. The first substrate 31 extends downwardly and encloses a space (which can be the accommodating space 33 in FIG. 4) with the first heat dissipation portion 32, and the first heat exchanger 4 is installed in the space, which makes the heat sink 3 and the first heat exchanger 4 more compactly installed and reduces the space occupied by the heat dissipation cavity 112. In addition, the first power device 21 is in contact with the protruding portion of the first substrate 31 (see FIG. 5), and the heat conduction plate 43 is in contact with the protruding portion of the first substrate 31 and cooperates with the heat dissipation fins 44 to also assist in dissipating heat from the first power device 21.

[0158] In some examples, referring to FIG. 22, the power device further includes a power device such as an inductor 24 (different from the inductors in the plurality of electronic devices 25) that generates more heat, and the inductor 24 and other power devices that generate more heat are arranged in the heat dissipation cavity 112 and fixedly connected to the partition plate 11, which is conducive to dissipating heat from such devices. The inductor 24 and other power devices that generate more heat can be electrically connected to the circuit board 2 by wires, and the wires pass through the partition plate 11. In order to reasonably utilize the space in the heat dissipation cavity 112, the inductor 24 can be located above the first substrate 31.

[0159] In addition, in order to facilitate heat dissipation, referring to FIGS. 1 and 2, in an example, the power conversion device 100 further includes a first fan 8, and the heat dissipation hole 121 includes an air inlet hole 1211 and an air outlet hole 1212, one of which is located below the heat sink 3 and the other of which is located above the heat sink 3, that is, the air inlet hole 1211 and the air outlet hole 1212 are located on the upper and lower sides of the heat sink 3, respectively, and the first fan 8 is configured to drive the air entering through the air inlet hole 1211 to exit from the air outlet hole 1212. Under the action of the first fan 8, the air outside the protective cover 12 enters through the air inlet hole 1211, passes through the heat sink 3, and then exits from the air outlet hole 1212, so that the external air can fully pass through the heat sink 3, thereby improving the heat dissipation effect of the heat sink 3.

[0160] For example, the air inlet hole 1211 is arranged below the heat sink 3, and the air outlet hole 1212 is arranged above the heat sink 3. The air in the heat dissipation cavity 112 after heat exchange with the heat exchanger and the heat sink 3 has a higher temperature, and the density of hot air is smaller than that of cold air. Therefore, the same volume of hot air is lighter than cold air, so that the hot air rises. Therefore, the air inlet hole 1211 is arranged below and the air outlet hole 1212 is arranged above, which is more in line with the flow rule of the air in the heat dissipation cavity 112, so that the heat dissipation effect in the heat dissipation cavity 112 is better.

[0161] The air inlet hole 1211 and the air outlet hole 1212 can be provided in plurality, and in some examples, the air inlet hole 1211 and the air outlet hole 1212 have the same shape and size.

[0162] FIG. 23 schematically shows the internal structure of another power conversion device 100, and FIG. 24 schematically shows an exploded view of the partial structure of the power conversion device 100 in FIG. 23. The structure of the housing 1 and the structure of the protective cover 12 in this example can be the same as the structure of the housing 1 and the structure of the protective cover 12 shown in FIG. 1. In the example shown in FIG. 23 and FIG. 24, the heat sink 3 further includes a second base plate 36 and a second heat dissipation portion 37 in addition to the first base plate 31 and the first heat dissipation portion 32. The second base plate 36 is distributed and fixedly connected with the first base plate 31 in the vertical direction.

[0163] FIG. 25 schematically shows the internal cavity of the second base plate 36 and the second heat dissipation portion 37. Referring to FIG. 24 and FIG. 25, the third gas-liquid passage 360 is provided in the second base plate 36, and the cooling working medium for gas-liquid conversion is provided in the third gas-liquid passage 360 of the second base plate 36. The fourth gas-liquid passage 370 is provided in the second heat dissipation portion 37 and is in communication with the third gas-liquid passage 360. The third gas-liquid passage 360 is isolated from the first gas-liquid passage 310, that is, the second base plate 36 and the first base plate 31 are not in communication with each other. In addition, the second heat dissipation portion 37 is arranged on the side of the second base plate 36 away from the partition plate 11.

[0164] Referring to FIG. 24, the second power device 23 is provided on the side of the circuit board 2 facing the opening 113 in addition to the first power device 21. In some examples, the second power device 23 can also constitute the power conversion circuit of the power conversion device 100 to perform power conversion on the direct current input to the power conversion device 100. For example, the second power device 23 includes a chip. In other examples, the second power device 23 can also be a power device on the circuit board 2 that serves other purposes. The second power device 23 is in contact with the second base plate 36. When there are more power devices on the circuit board 2 that need to be cooled and there is a height difference between different power devices (the first power device 21 and the second power device 23), the second base plate 36 and the second heat dissipation portion 37 can better cool the second power device 23, thereby reducing the possibility that the second power device 23 is overheated and affects the normal operation of the power conversion device 100.

[0165] The first substrate 31 and the second substrate 36 are connected to seal the opening 113, reducing the possibility of air in the heat dissipation cavity 112 entering the power cavity 111. In addition, the power cavity 111 (for example, the interior of the shell 1 in FIG. 23) and the heat dissipation cavity 112 are distributed along the first direction, and the first substrate 31 and the second substrate 36 are distributed along the vertical direction, which can reduce the size of the heat sink 3 in the first direction, and thus reduce the size of the heat dissipation cavity 112 in the first direction, and reduce the size of the power conversion device 100 in the first direction.

[0166] In some examples, referring to FIG. 25, the second substrate 36 protrudes downward toward the second heat dissipation part 37, and the second power device 23 is partially located below the second heat dissipation part 37. The overlapping area of the second heat dissipation part 37 and the second power device 23 is reduced, which can allow the second heat dissipation part 37 to have more area to exchange heat with the air in the heat dissipation cavity 112, and is conducive to improving the heat dissipation effect. In other examples, the second power device 23 is completely located below the second heat dissipation part 37, that is, the second power device 23 and the second heat dissipation part 37 are respectively located on both sides of the second substrate 36, and the second power device 23 and the second heat dissipation part 37 have a spacing in the vertical direction.

[0167] In some examples, referring to FIG. 25, the structure of the second substrate 36 can be the same as that of the first substrate 31. In other examples, the second substrate 36 is other structures capable of playing the same role as the first substrate 31. In addition, the sizes of the first substrate 31 and the second substrate 36 can be the same or different, and the present application does not make specific limitations on this. In the examples shown in FIGS. 23-25, the first substrate 31 is located above the second substrate 36. In this example, the first heat dissipation part 32 is also located above the second heat dissipation part 37. In other examples, the first substrate 31 can also be located below the second substrate 36. In this example, the first heat dissipation part 32 is also located below the second heat dissipation part 37.

[0168] Referring to FIG. 24, the second heat dissipation part 37 can include a plurality of second condensing pipes 371 arranged at intervals, and a plurality of fins 34 are arranged between adjacent two second condensing pipes 371 (similar to the structure of the first heat dissipation part 32 in FIG. 6). Among the first heat dissipation part 32 and the second heat dissipation part 37, the number of fins 34 arranged by the one closer to the air inlet hole 1211 is less than the number of fins 34 arranged by the one farther from the air inlet hole 1211.

[0169] Since the air at the air inlet hole 1211 just enters the heat dissipation cavity 112 from the outside, the air temperature is lower the closer to the air inlet hole 1211. When the air passes through one of the first heat dissipation part 32 and the second heat dissipation part 37 closer to the air inlet hole 1211, heat exchange occurs, and the temperature of the air after heat exchange rises. That is, in the heat dissipation cavity 112, the air temperature is higher the closer to the air outlet hole 1212. The one of the first heat dissipation part 32 and the second heat dissipation part 37 closer to the air inlet hole 1211 is arranged with the sparse fins 34 to make the air pass through in large quantities, and more air blows to the one farther away. The one farther away from the air inlet hole 1211 is arranged with the dense secondary fins 34 to enhance the heat dissipation capacity, so that the vertically arranged first heat dissipation part 32 and second heat dissipation part 37 can balance heat dissipation.

[0170] Referring to FIGS. 23 and 24, taking the example that the air inlet hole 1211 is located below the heat sink 3, if the first heat dissipation part 32 is located above the second heat dissipation part 37, the fins 34 of the second heat dissipation part 37 are more sparse than those of the first heat dissipation part 32, that is, the fins 34 of the first heat dissipation part 32 are more dense than those of the second heat dissipation part 37. In the example that the air inlet hole 1211 is located above the heat sink 3, if the first heat dissipation part 32 is located above the second heat dissipation part 37, the fins 34 of the second heat dissipation part 37 are more dense than those of the first heat dissipation part 32, that is, the fins 34 of the first heat dissipation part 32 are more sparse than those of the second heat dissipation part 37.

[0171] In other examples, referring to FIG. 26, which exemplarily shows another arrangement of the first heat dissipation part 32 and the second heat dissipation part 37, in this example, the one of the first heat dissipation part 32 and the second heat dissipation part 37 closer to the air inlet hole 1211 has a size in the first direction smaller than that of the one farther away from the air inlet hole 1211. That is, the heat dissipation part closer to the air inlet hole 1211 is shorter in the first direction. The arrangement of different lengths makes more cold air blow to the one of the first heat dissipation part 32 and the second heat dissipation part 37 farther away from the air inlet hole 1211, and enhances the heat dissipation capacity of the heat sink 3, so that the vertically arranged first heat dissipation part 32 and second heat dissipation part 37 can balance heat dissipation.

[0172] In the example shown in FIG. 26, the fins 34 can not be arranged, or the fins 34 can be arranged in the first heat dissipation part 32 and the second heat dissipation part 37, and the density of the fins 34 can be arranged according to the distance from the air inlet hole 1211, which will not be described here.

[0173] Referring back to FIG. 23 and FIG. 24, the power conversion device 100 further comprises a second heat exchanger 5 arranged in the heat dissipation cavity 112, the second heat exchanger 5 is used to transfer heat in the power cavity 111 to the heat dissipation cavity 112 to dissipate heat for the electronic device 25. For example, the second heat exchanger 5 is provided with a second heat exchange channel (not shown in the drawings as it is located in the second heat exchanger 5), the second heat exchange channel is in communication with the power cavity 111 (located in the housing 1), the hot air in the power cavity 111 can exchange heat with the air in the heat dissipation cavity 112 through the first heat exchanger 4 and the second heat exchanger 5, further reducing the temperature in the power cavity 111, so that the power conversion device 100 can stably operate.

[0174] Referring to FIG. 23, since the first substrate 31 protrudes downward of the first heat dissipation part 32, and the second substrate 36 extends downward of the second heat dissipation part 37, there is a surplus space below the first heat dissipation part 32 and the second heat dissipation part 37, one of the first heat exchanger 4 and the second heat exchanger 5 is arranged between the first heat dissipation part 32 and the second heat dissipation part 37, and the other is located below the one with lower height of the first heat dissipation part 32 and the second heat dissipation part 37.

[0175] That is, when the first heat exchanger 4 and the second heat exchanger 5 are arranged, the surplus space below the first heat dissipation part 32 and the second heat dissipation part 37 is fully utilized, the installation of the heat sink 3, the first heat exchanger 4 and the second heat exchanger 5 is more compact, the space in the vertical direction of the heat dissipation cavity 112 is fully utilized, and the size of the power conversion device 100 in the first direction is reduced.

[0176] For example, in the example shown in FIG. 23, the first heat dissipation part 32 is located above the second heat dissipation part 37, then the accommodation space 33 is located between the first heat dissipation part 32 and the second heat dissipation part 37 (see FIG. 24 for reference), the first heat exchanger 4 is arranged between the first heat dissipation part 32 and the second heat dissipation part 37, and the second heat exchanger 5 is arranged below the second heat dissipation part 37. In other examples, the first heat dissipation part 32 is located below the second heat dissipation part 37, then the second heat exchanger 5 is arranged between the first heat dissipation part 32 and the second heat dissipation part 37, and the first heat exchanger 4 is arranged below the first heat dissipation part 32.

[0177] In one example, in order to facilitate the unified installation of the first heat exchanger 4 and the second heat exchanger 5, the first heat exchanger 4 and the second heat exchanger 5 can be connected, and FIG. 27 exemplarily shows this structure. Referring to FIG. 27, the inlet of the first heat exchange channel in the first heat exchanger 4 and the inlet of the second heat exchange channel in the second heat exchanger 5 are both in communication with the first connecting pipe 6, the outlet of the heat exchange channel in the first heat exchanger 4 and the outlet of the heat exchange channel in the second heat exchanger 5 are both in communication with the second connecting pipe 7, and the first connecting pipe 6 and the second connecting pipe 7 are both in communication with the power cavity 111.

[0178] The first heat exchanger 4 and the second heat exchanger 5 are communicated and fixed by the first connecting pipe 6 and the second connecting pipe 7, the integration of the first heat exchanger 4 and the second heat exchanger 5 is improved, the first heat exchanger 4 and the second heat exchanger 5 do not need to be respectively installed and communicated with the power cavity 111, and unified disassembly of the first heat exchanger 4 and the second heat exchanger 5 in the heat dissipation cavity 112 is facilitated.

[0179] The first connecting pipe 6 is provided with a heat exchange inlet 61, and the second connecting pipe 7 is provided with a heat exchange outlet 71. The heat exchange inlet 61 and the heat exchange outlet 71 are respectively communicated with the corresponding installation port 114 on the partition plate 11 (returning to refer to FIG. 24), so as to realize the communication of the internal heat exchange channels of the first heat exchanger 4 and the second heat exchanger 5 with the power cavity 111. The hot air in the power cavity 111 enters the first heat exchanger 4 and the second heat exchanger 5 through the first connecting pipe 6, respectively, the hot air in the first heat exchanger 4 and the second heat exchanger 5 is exchanged with the air in the heat dissipation cavity 112, and then enters the second connecting pipe 7, and then enters the power cavity 111 through the second connecting pipe 7.

[0180] In an example, referring to FIG. 23, the first heat exchange channel of the first heat exchanger 4 and the second heat exchange channel of the second heat exchanger 5 both extend along the second direction, and the first connecting pipe 6 and the second connecting pipe 7 are located on different sides of the one of the first heat dissipation part 32 and the second heat dissipation part 37 with lower height. For example, in the example shown in FIG. 23, the first heat dissipation part 32 is located above the second heat dissipation part 37, and the first connecting pipe 6 and the second connecting pipe 7 are located on different sides of the second heat dissipation part 37 in the second direction.

[0181] Through the above design manner, the first heat dissipation part 32, the first heat exchanger 4, the second heat dissipation part 37 and the second heat exchanger 5 are alternately distributed, the space above and below the one of the first heat dissipation part 32 and the second heat dissipation part 37 with lower height is respectively utilized by the first heat exchanger 4 and the second heat exchanger 5, and the space on both sides of the one of the first heat dissipation part 32 and the second heat dissipation part 37 with lower height is respectively utilized by the first connecting pipe 6 and the second connecting pipe 7, so that the space of the heat dissipation cavity 112 can be more fully utilized, and the volume of the power conversion device 100 is reduced.

[0182] In an example, referring to FIG. 27, the second heat exchanger 5 includes a fin heat exchanger, for example, the second heat exchanger 5 includes a plurality of second flat heat dissipation pipes 51 and a plurality of second heat dissipation fins 52 (for example, a structure similar to a fin), the plurality of second flat heat dissipation pipes 51 are spaced apart along the first direction, a plurality of second heat dissipation fins 52 are arranged between each group of two adjacent second flat heat dissipation pipes 51, and the internal space of the plurality of second flat heat dissipation pipes 51 forms the second heat exchange channel of the second heat exchanger 5. In other examples, the second heat exchange channel in the second heat exchanger 5 includes a channel similar to an "S" shape or a channel similar to a snake shape.

[0183] In some examples, in order to facilitate the air in the power cavity 111 to flow in the first heat exchanger 4 and the second heat exchanger 5, a driving fan (not shown in the drawings) can be arranged in the power cavity 111 to drive the air flow.

[0184] In other examples, the structure and arrangement position of the first heat exchanger 4 can also be adjusted according to requirements. For example, FIG. 28 exemplarily shows the internal structure of another power conversion device 100, and FIG. 29 exemplarily shows an exploded view of part of the structure of the power conversion device 100 in FIG. 28. Referring to FIGS. 28 and 29, the partition plate 11 is provided with a through opening 115, and the first heat exchanger 4 includes a heat-conducting plate 43 (for example, a metal plate) and a plurality of heat dissipation fins 44 (for example, metal sheets). The plurality of heat dissipation fins 44 include a plurality of first heat dissipation fins 441 and a plurality of second heat dissipation fins 442. The heat-conducting plate 43 is arranged at the through opening 115, and the first heat dissipation fins 441 and the second heat dissipation fins 442 are respectively fixed to different plate surfaces of the heat-conducting plate 43. Moreover, the plurality of first heat dissipation fins 441 are arranged in the second direction at intervals, and the plurality of second heat dissipation fins 442 are arranged in the second direction at intervals. The heat-conducting plate 43 and the first heat dissipation fins 441 are located in the heat dissipation cavity 112, and the second heat dissipation fins 442 extend into the power cavity 111 through the through opening 115.

[0185] In other examples, FIG. 30 exemplarily shows the internal structure of another power conversion device 100. The heat-conducting plate 43 and the second heat dissipation fins 442 are located in the power cavity 111, and the first heat dissipation fins 441 extend into the heat dissipation cavity 112 through the through opening 115.

[0186] Referring to any one of FIGS. 28 to 30, the heat dissipation cavity 112 is provided with a second fan 9 for generating air flow through the first heat dissipation fins 441. By arranging the second fan 9, the air in the power cavity 111 flows, and the heat in the power cavity 111 can be continuously conducted to the second heat dissipation fins 422 and transmitted outward through the second heat dissipation fins 422.

[0187] In addition, referring to any one of FIGS. 28 to 30, the heat dissipation cavity 112 can also be provided with a first fan 8 for generating air flow through the first heat dissipation fins 441. After the temperature of the power cavity 111 rises, the heat in the power cavity 111 is transmitted to the heat-conducting plate 43 through the second heat dissipation fins 442, and the heat is transmitted to the first heat dissipation fins 441 through the heat-conducting plate 43. The first fan 8 blows air towards the first heat dissipation fins 441, which can blow the heat on the first heat dissipation fins 441 to the outside of the heat dissipation cavity 112, that is, to the outside, thereby continuously dissipating the heat of the first heat dissipation fins 441, that is, dissipating the heat of the power cavity 111, and reducing the internal temperature of the power cavity 111.

[0188] In the case where the first heat exchanger 4 includes the heat-conductive plate 43, the plurality of first heat dissipation fins 441, and the plurality of second heat dissipation fins 442, in the examples shown in FIGS. 28 to 30, the first heat exchanger 4 is arranged in the vertical direction with respect to the heat sink 3, for example, below the heat sink 3. In other examples, the first heat exchanger 4 can also be arranged in the horizontal direction (for example, the second direction) with respect to the heat sink 3, and FIG. 31 exemplarily shows a plurality of positions of the first heat exchanger. Referring to (a) of FIG. 31, the first heat exchanger 4 can be provided on one side of the heat sink 3 in the second direction. Referring to (b) and (c) of FIG. 31, the heat sink 3 is provided with one through opening 115 (the structure of the through opening 115 is described with reference to any one of FIGS. 28 to 30) on each of the two sides of the heat sink 3 in the second direction, one first heat exchanger 4 is provided at the through opening 115 on one side of the heat sink 3, one second heat exchanger 5 (the structure of the second heat exchanger 5 is the same as that of the first heat exchanger 4) is provided at the through opening 115 on the other side of the heat sink 3, or one first heat exchanger 4 is provided at each of the through openings 115 (one first heat exchanger 4 is provided on each of the two sides of the heat sink 3 in the second direction).

[0189] In some examples, the first substrate 31 and the second substrate 36 can be integrally connected, and in other examples, the first substrate 31 and the second substrate 36 can be separately provided and fixedly connected to each other (directly fixed or indirectly fixed through other structures).

[0190] In some examples, the first heat exchanger 4 can be separately provided from the first substrate 31 and respectively installed in the heat dissipation cavity 112. In other examples, the first heat exchanger 4 can be integrally connected to the first substrate 31.

[0191] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power conversion device, characterized by, The power conversion device comprises a shell, a circuit board, a heat sink and a first heat exchanger, The shell is provided with a sealed power cavity and an open ventilation heat dissipation cavity, the shell comprises a partition plate between the power cavity and the heat dissipation cavity, the protection level of the power cavity is higher than that of the heat dissipation cavity, the partition plate is provided with an opening, the circuit board is arranged in the power cavity, the first power device is arranged on the side of the circuit board facing the opening, and the first power device constitutes a power conversion circuit of the power conversion device to perform power conversion on the input direct current of the power conversion device. The heat sink is arranged in the heat dissipation cavity and comprises a first base plate and a first heat dissipation part, the first base plate is arranged at the opening and is in thermal contact with the first power device in the power cavity, the first heat dissipation part extends outward from the first base plate, the first base plate is provided with a first gas-liquid channel, the first heat dissipation part is provided with a second gas-liquid channel in communication with the first gas-liquid channel, the first gas-liquid channel is provided with a cooling working medium for gas-liquid conversion, and the included angle between the first gas-liquid channel and the second gas-liquid channel is 90 degrees or greater than 90 degrees and less than 180 degrees. The circuit board is provided with an electronic device on the side opposite to the first power device, the first heat exchanger is arranged in the power cavity or the heat dissipation cavity, and the first heat exchanger is used for transferring heat in the power cavity to the heat dissipation cavity to dissipate heat of the electronic device.

2. The power conversion device of claim 1, wherein, The first base plate extends in the vertical direction and protrudes from the first heat dissipation part, and the first power device is in thermal contact with the part of the first base plate protruding from the first heat dissipation part.

3. A power conversion device according to claim 1 or 2, characterized in that The first heat exchanger is arranged in the power cavity, the first heat exchanger is provided with a first heat exchange channel, the first heat exchange channel is isolated from the power cavity, the first heat exchange channel has an inlet and an outlet arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are in communication with the heat dissipation cavity; or, the first heat exchanger is arranged in the heat dissipation cavity, the first heat exchanger is provided with a first heat exchange channel, the first heat exchange channel is isolated from the heat dissipation cavity, the first heat exchange channel has an inlet and an outlet arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are in communication with the power cavity.

4. The power conversion device of claim 3, wherein, The first base plate extends in the vertical direction and protrudes from the first heat dissipation part, and the first heat exchanger crosses the first base plate and overlaps with the part of the first base plate protruding from the first heat dissipation part.

5. The power conversion device according to claim 1 or 2, characterized by, The first heat exchanger is arranged in the heat dissipation cavity, the first heat exchanger comprises a heat conduction plate and a heat dissipation fin connected to each other, the heat conduction plate is in thermal contact with the first base plate, the heat dissipation cavity is provided with a first fan, and the first fan is used to generate airflow through the heat dissipation fin.

6. The power conversion device of claim 5, wherein, The first base plate extends in the vertical direction and protrudes from the first heat dissipation part, the heat conduction plate is in thermal contact with the part of the first base plate protruding from the first heat dissipation part, and the heat dissipation fin is located below the first heat dissipation part.

7. The power conversion device according to claim 1 or 2, characterized by The partition plate is provided with a through hole, the first heat exchanger comprises a heat conduction plate and a plurality of heat dissipation fins, the plurality of heat dissipation fins comprise first and second heat dissipation fins, the heat conduction plate is arranged at the through hole, and the first and second heat dissipation fins are respectively fixed to different plate surfaces of the heat conduction plate; The heat conduction plate and the first heat dissipation fin are located in the heat dissipation cavity, and the second heat dissipation fin extends into the power cavity through the through hole; or the heat conduction plate and the second heat dissipation fin are located in the power cavity, and the first heat dissipation fin extends into the heat dissipation cavity through the through hole; The power cavity is provided with a second fan for generating airflow through the second heat dissipation fin.

8. The power conversion device of claim 1, wherein, The power cavity and the heat dissipation cavity are distributed along a first direction, the first direction is perpendicular to a vertical direction, the heat sink further comprises a second base plate and a second heat dissipation part, the second base plate is distributed and fixedly connected with the first base plate along the vertical direction, the second heat dissipation part extends outward from the second base plate, the second base plate is provided with a third gas-liquid channel, the second heat dissipation part is provided with a fourth gas-liquid channel in communication with the third gas-liquid channel, the third gas-liquid channel is isolated from the first gas-liquid channel, one side of the circuit board facing the opening is provided with a second power device, the second power device is in contact with the second base plate in the heat dissipation cavity, and the third gas-liquid channel is provided with a cooling working medium for gas-liquid conversion.

9. The power conversion device of claim 8, wherein, The power conversion device further comprises a second heat exchanger, the second heat exchanger is used for transferring heat in the power cavity to the heat dissipation cavity, the first heat exchanger and the second heat exchanger are both arranged in the heat dissipation cavity, The first heat dissipation part and the second heat dissipation part are distributed along the vertical direction, the first base plate protrudes towards the lower side of the first heat dissipation part, the second base plate protrudes towards the lower side of the second heat dissipation part, one of the first heat exchanger and the second heat exchanger is located between the first heat dissipation part and the second heat dissipation part, and the other is located below the lower one of the first heat dissipation part and the second heat dissipation part.

10. The power conversion device of claim 9, wherein, The first heat exchanger is formed with a first heat exchange channel, the second heat exchanger is formed with a second heat exchange channel, the inlet of the first heat exchange channel and the inlet of the second heat exchange channel are communicated with a first connecting pipe, the outlet of the first heat exchange channel and the outlet of the heat exchange channel are communicated with a second connecting pipe, and the first connecting pipe and the second connecting pipe are both located in the heat dissipation cavity and communicated with the power cavity.

11. The power conversion device of claim 10, wherein, The first heat exchange channel and the second heat exchange channel both extend along a second direction, The first connecting pipe and the second connecting pipe are respectively located on different sides of the lower one of the first heat dissipation part and the second heat dissipation part in the second direction, The first direction, the second direction and the vertical direction are perpendicular to each other.

12. A power conversion device according to any one of claims 8-11, characterized in that, The power conversion device further comprises a protective cover, the heat dissipation cavity is formed in the protective cover, the protective cover is provided with a heat dissipation hole, the heat dissipation hole comprises an air inlet hole and an air outlet hole, one of the air inlet hole and the air outlet hole is located below the radiator, and the other is located above the radiator, a first fan is arranged in the heat dissipation cavity, and the first fan is used for driving the air entering through the air inlet hole to be discharged from the air outlet hole.

13. The power conversion device of claim 12, wherein, The first heat dissipation part comprises a plurality of first condensing pipes arranged at intervals, the second heat dissipation part comprises a plurality of second condensing pipes arranged at intervals, a plurality of fins are arranged between adjacent two first condensing pipes and between adjacent two second condensing pipes, The number of fins arranged in the one of the first heat dissipation part and the second heat dissipation part which is closer to the air inlet hole is smaller than the number of fins arranged in the one which is farther away from the air inlet hole.

14. A power conversion device according to claim 12 or 13, characterised in that, The size of the one of the first heat dissipation part and the second heat dissipation part which is closer to the air inlet hole in the first direction is smaller than the size of the one which is farther away from the air inlet hole in the first direction.

15. The power conversion device of any one of claims 1-14, wherein, The included angle between the first gas-liquid channel and the second gas-liquid channel is greater than 90 degrees and less than or equal to 160 degrees.

16. The power conversion device of any one of claims 1-15, wherein, The first power device is fixedly connected with the first substrate by a bolt, the circuit board is provided with a through hole for the head of the bolt to pass through, the rod part of the bolt passes through the first power device and is threadedly connected with the first substrate, and the head of the bolt abuts against the surface of the first power device away from the first substrate.

17. The power conversion device of any one of claims 1-16, wherein, The inner wall surface of the first gas-liquid channel surrounded by the first substrate comprises a first wall surface and a second wall surface, the first wall surface and the second wall surface are oppositely arranged in the thickness direction of the first substrate, a plurality of support pieces are arranged between the first wall surface and the second wall surface, one end of each support piece is connected with or abuts against the first wall surface, and the other end is connected with or abuts against the second wall surface.

18. The power conversion device of claim 17, wherein, The first substrate comprises a bottom plate and a cover plate arranged in a first direction, the bottom plate is connected with the first power device, the cover plate is located on the side of the bottom plate away from the first power device, the edge of the cover plate is fixedly connected with the edge of the bottom plate, the cover plate is bulged toward the side away from the bottom plate, and the first gas-liquid channel is located between the cover plate and the bottom plate; one end of each support piece is integrally connected with the bottom plate, and the other end is connected with or abuts against the cover plate; The plurality of support pieces are divided into a plurality of support groups arranged in a vertical direction, each support group comprises a plurality of support pieces arranged in a second direction, and the first direction, the second direction and the vertical direction are perpendicular to each other. The flow equalization channels are communicated with the second gas-liquid channels; the upward surfaces of the support members in each row of the support groups are flush, the downward surfaces of the support members in each row of the support groups are flush, and the upward surfaces and the downward surfaces of each support member are parallel.

19. The power conversion device of any one of claims 1-18, wherein, The heat sink further comprises a flow collecting portion arranged in the heat dissipation cavity and connected to an end of the first heat dissipation portion away from the first substrate, the second gas-liquid channel comprises a plurality of sub-channels, and the flow collecting portion is provided with flow collecting channels communicated with different sub-channels in the second gas-liquid channel, so as to communicate the different sub-channels in the second gas-liquid channel with each other.

20. The power conversion device of claim 19, wherein, The heat sink further comprises a return pipe arranged below the first heat dissipation portion, one end of the return pipe being communicated with the first gas-liquid channel and the other end being communicated with the flow collecting channel.

21. A power conversion device according to claim 19 or 20, characterised in that, The flow collecting portion comprises a first plate and a second plate, the edges of the first plate and the edges of the second plate being fixedly connected, the first plate being connected to an end of the first heat dissipation portion away from the first substrate, the second plate being located on a side of the first plate away from the first heat dissipation portion, the second plate being bulged toward a side away from the first plate, and the flow collecting channel being located between the first plate and the second plate. The second plate is provided with a plurality of concave structures, the plurality of concave structures being recessed into the flow collecting channel toward a direction close to the first plate, and the plurality of concave structures being in abutment with the first plate.

22. The power conversion device of any one of claims 1-21, wherein, The first gas-liquid channel is provided with a first evaporation zone, the first evaporation zone being connected to an inner wall surface of the first substrate on a side close to the first power device, an outer wall surface corresponding to the inner wall surface of the first substrate connected to the first evaporation zone being in contact with the first power device, the first gas-liquid channel comprising a first chamber and a second chamber located on both sides of the first evaporation zone in the vertical direction, and the first evaporation zone being provided with a plurality of first flow channels communicated with the first chamber and the second chamber.

23. The power conversion device of claim 22, wherein, Both sides of the first evaporation zone are provided with second evaporation zones, the distribution directions of the two second evaporation zones being perpendicular to the vertical direction, the second evaporation zones being provided with a plurality of second flow channels communicated with the first chamber and the second chamber, and the number of the second flow channels on each second evaporation zone being less than the number of the first flow channels.

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