Power conversion device

Abstract

The embodiment of the application provides a kind of power conversion equipment, it is related to power electronics field.The power conversion equipment includes shell, circuit board, radiator and first heat exchanger, power cavity is formed in shell, heat dissipation cavity is formed outside shell, shell includes the partition between power cavity and heat dissipation cavity, opening is arranged on the partition, circuit board is arranged in power cavity and the side of opening has first power device;Radiator is arranged in heat dissipation cavity and includes first substrate and first heat dissipation part, first substrate is arranged at opening and is in contact with first power device, first substrate is provided with first gas-liquid passage, first heat dissipation part is provided with second gas-liquid passage communicated with first gas-liquid passage, and cooling working medium for gas-liquid conversion is arranged in first gas-liquid passage;First heat exchanger is located in power cavity or heat dissipation cavity.Through the above technical scheme, the device that can be targeted to heat seriously in power conversion equipment is cooled, so that power conversion equipment is stably operated.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power conversion device. Background Technology

[0002] An inverter is a power conversion device that converts direct current (DC) to alternating current (AC). Inverters and other power conversion devices generate significant heat during operation. With technological advancements, the demand for heat dissipation in inverters and other power conversion devices has increased dramatically.

[0003] In related technologies, heat dissipation is achieved through overall heat dissipation of the entire power conversion device. However, power conversion devices include multiple high-power components, such as high-power chips. These components generate significant heat, and the heat dissipation methods used in these technologies cannot provide precise cooling for them, thus affecting the operational stability of the power conversion device. Summary of the Invention

[0004] This application provides a power conversion device that can perform targeted heat dissipation on components that generate significant heat in the power conversion device, thereby enabling the power conversion device to operate stably.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a power conversion device, which includes a housing, a circuit board, a heat sink, and a first heat exchanger. A sealed power cavity is formed inside the housing, and an open, ventilated heat dissipation cavity is formed outside the housing. The housing includes a partition between the power cavity and the heat dissipation cavity. The power cavity has a higher protection level than the heat dissipation cavity. An opening is provided on the partition. The circuit board is disposed inside the power cavity, and a first power device is mounted on the side of the circuit board facing the opening. The first power device constitutes the power conversion circuit of the power conversion device to convert the DC power input to the power conversion device. The heat sink is disposed inside the heat dissipation cavity and includes a first substrate and a first heat dissipation section. The circuit board is positioned at the opening and makes thermal contact with the first power device within the heat dissipation cavity. The first heat dissipation section extends outward from the first substrate. A first gas-liquid channel is provided within the first substrate, and a second gas-liquid channel communicating with the first gas-liquid channel is provided within the first heat dissipation section. A cooling medium for gas-liquid conversion is provided within the first gas-liquid channel. The 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. Electronic devices are mounted on the side of the circuit board opposite to where the first power device is mounted. A first heat exchanger is located within the power cavity or heat dissipation cavity and is used to transfer heat from the power cavity to the heat dissipation cavity to cool the electronic devices.

[0007] When the first power device in the power conversion equipment generates significant heat, the heat is transferred to the first substrate, heating the cooling medium within the substrate. As the liquid cooling medium in the first gas-liquid channel heats up, at least a portion of it becomes gaseous. This gaseous cooling medium flows (rises) into the second gas-liquid channel of the first heat dissipation section. The open, ventilated heat dissipation cavity facilitates heat exchange between the cooling medium in the first heat dissipation section and the external environment, causing the gaseous cooling medium to rapidly dissipate heat and condense within the first heat dissipation section, gradually returning to a liquid state before flowing back into the first substrate. This cycle continues, continuously dissipating heat for the first power device. This application enables the power conversion equipment to operate stably by providing targeted heat dissipation for devices generating significant heat (e.g., the first power device).

[0008] Furthermore, the power cavity is sealed and has a higher protection level than the heat dissipation cavity, which reduces the possibility of external impurities entering the power cavity. Additionally, the first substrate is positioned at the opening, allowing it to contact the first power device while also shielding the opening, further reducing the possibility of mutual interference between the heat dissipation cavity and the power cavity. This allows the circuit board to be placed within a relatively well-protected cavity, ensuring the safety of other components while dissipating heat from the heat-generating device, and reducing the risk of power conversion equipment failure.

[0009] Furthermore, the circuit board is located inside the power cavity. When the power conversion device is running, the circuit board and the electronic components on it generate a lot of heat, making the temperature inside the power cavity high. The first heat exchanger allows the hot air inside the power cavity to exchange heat with the cold air inside the heat dissipation cavity, reducing the temperature inside the power cavity and enabling the power conversion device to operate stably.

[0010] In one alternative embodiment, the first substrate protrudes downward toward the first heat sink, and the first power device is at least partially located below the first heat sink.

[0011] The overlap area between the first heat dissipation section and the first power device is small, which allows more area of ​​the first heat dissipation section to exchange heat with the air in the heat dissipation cavity. This reduces the impact of the heat from the first power device on the condensation of the cooling medium in the first heat dissipation section, allowing the cooling medium to condense quickly in the first heat dissipation section, which is beneficial to improving the heat dissipation effect of the heat sink.

[0012] In one optional embodiment, the first heat exchanger is located inside the power cavity, and a first heat exchange channel is formed inside the first heat exchanger. The first heat exchange channel is isolated from the power cavity and has an inlet and an outlet disposed on the first heat exchanger. Both the inlet and outlet of the first heat exchange channel are connected to the heat dissipation cavity.

[0013] Air in the heat dissipation cavity can enter the first heat exchange channel and then exchange heat with the hot air in the power cavity through the first heat exchanger. The heat dissipation cavity is open for ventilation, so that outside air can continuously enter the first heat exchange channel, reducing the temperature in the power cavity and enabling the power conversion equipment to operate stably.

[0014] In one optional embodiment, the first heat exchanger is located inside the heat dissipation cavity, and a first heat exchange channel is formed inside the first heat exchanger. The first heat exchange channel is isolated from the heat dissipation cavity. The first heat exchange channel has an inlet and an outlet disposed on the first heat exchanger, and both the inlet and outlet of the first heat exchange channel are connected to the power cavity.

[0015] The first heat exchanger allows hot air from the power cavity to enter the first heat exchange channel, where it exchanges heat with the air in the heat dissipation cavity. By designing the heat dissipation cavity as an open, ventilated structure, sufficient heat exchange between the air in the first heat exchange channel and the surrounding cool air is achieved, lowering the temperature within the power cavity and enabling stable operation of the power conversion equipment. Furthermore, placing the first heat exchanger within the heat dissipation cavity improves heat dissipation efficiency and accelerates the heat dissipation rate.

[0016] In one alternative embodiment, the first substrate protrudes downward toward the first heat dissipation portion, and the first heat exchanger is at least partially located between the portion of the first substrate protruding from the first heat dissipation portion and the first heat dissipation portion.

[0017] In order to ensure that the first power device is at least partially located below the first heat sink, the first substrate extends downward and forms a space with the first heat sink, and the first heat exchanger is installed in this space, which can make the heat sink and the first heat exchanger more compact and reduce the space occupied by the heat sink cavity.

[0018] In one optional embodiment, the first heat exchanger is located inside the heat dissipation cavity. The first heat exchanger includes a heat-conducting plate and heat dissipation fins connected to each other. The heat-conducting plate is thermally bonded to the first substrate. A fan is provided inside the heat dissipation cavity to generate airflow through the heat dissipation fins.

[0019] As the temperature of the electronic components rises, the temperature of the power cavity also rises. The heat inside the power cavity is transferred to the heat-conducting plate through the first substrate, and then the heat-conducting plate transfers the heat to the heat sink fins. The fan blows air towards the heat sink fins, and the heat sink cavity is open for ventilation, which allows the heat on the heat sink fins to be blown out of the heat sink cavity, that is, blown to the outside. As the fan rotates continuously, it can continuously dissipate heat from the heat sink fins, which is to indirectly dissipate heat from the electronic components in the power cavity.

[0020] In one optional embodiment, the first substrate protrudes downward toward the first heat dissipation portion, a heat-conducting plate is thermally bonded to the portion of the first substrate protruding from the first heat dissipation portion, and heat dissipation fins are located below the first heat dissipation portion.

[0021] The first substrate extends downwards and forms a space with the first heat dissipation part. The first heat exchanger is installed within this space, allowing for a more compact installation of the heat sink and the first heat exchanger, reducing the space occupied by the heat dissipation cavity. Furthermore, the first power device contacts the protruding portion of the first substrate, and the heat-conducting plate also contacts the protruding portion of the first substrate. Combined with the heat dissipation fins, this further improves heat dissipation for the first power device.

[0022] In one optional embodiment, the power cavity and the heat dissipation cavity are distributed along a first direction, which is perpendicular to the vertical direction. The heat sink further includes a second substrate and a second heat dissipation part. The second substrate and the first substrate are distributed along the vertical direction and fixedly connected. The second heat dissipation part extends outward from the second substrate. A third gas-liquid channel is provided in the second substrate. A fourth gas-liquid channel communicating with the third gas-liquid channel is provided in the second heat dissipation part. The third gas-liquid channel is isolated from the first gas-liquid channel. A second power device is provided on the side of the circuit board facing the opening. The second power device is in contact with the second substrate in the heat dissipation cavity. A cooling medium for gas-liquid conversion is provided in the third gas-liquid channel.

[0023] With a height difference between the first power device and the second power device, the second substrate and the second heat sink can better dissipate heat for the second power device, reducing the possibility that the power conversion device may be affected by excessive heat generation from the second power device. Furthermore, the power cavity and heat sink 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, thus reducing the size of the heat sink cavity in the first direction and consequently reducing the size of the power conversion device in the first direction.

[0024] In one optional embodiment, the power conversion device further includes a second heat exchanger for transferring heat from the power cavity to the heat dissipation cavity. Both the first and second heat exchangers are disposed within the heat dissipation cavity. The first and second heat dissipation portions are distributed vertically. The first substrate protrudes downward toward the first heat dissipation portion, and the second substrate protrudes downward toward the second heat dissipation portion. One of the first and second heat exchangers is located between the first and second heat dissipation portions, and the other is located below the one with the lower height of the first and second heat dissipation portions.

[0025] The hot air in the power cavity can exchange heat with the air in the heat dissipation cavity through the first and second heat exchangers, further reducing the temperature inside the power cavity and enabling the power conversion device to operate stably. Since the first substrate protrudes downwards from the first heat dissipation section, and the second substrate protrudes downwards from the second heat dissipation section, there is ample space below both the first and second heat dissipation sections. When installing the first and second heat exchangers, this ample space can be fully utilized, resulting in a more compact installation of the heat sink, the first heat exchanger, and the second heat exchanger. This maximizes the use of space within the heat dissipation cavity and reduces the size of the power device in the first direction.

[0026] In one optional embodiment, a first heat exchange channel is formed in the first heat exchanger, and a second heat exchange channel is formed in the second heat exchanger. The inlet of the first heat exchange channel and the inlet of the second heat exchange channel are both connected to a first connecting pipe. The outlet of the first heat exchange channel and the outlet of the heat exchange channel are both connected to the second connecting pipe. The first connecting pipe and the second connecting pipe are both located in the heat dissipation cavity and are both connected to the power cavity.

[0027] Hot air from the power chamber enters the first and second heat exchangers respectively through the first connecting pipe. After exchanging heat with the air in the heat dissipation chamber, the hot air in the first and second heat exchangers enters the second connecting pipe and returns to the power chamber. The first and second heat exchangers are interconnected and fixed together through the first and second connecting pipes, which improves the integration of the first and second heat exchangers. It eliminates the need to connect the first and second heat exchangers separately to the power chamber, facilitating unified assembly and disassembly of the first and second heat exchangers within the heat dissipation chamber.

[0028] In one optional embodiment, both the first heat exchange channel and the second heat exchange channel extend along the second direction, and the first connecting pipe and the second connecting pipe are respectively located on the lower of the first heat dissipation part and the second heat dissipation part, on different sides of the second direction, with the first direction, the second direction and the vertical direction being perpendicular to each other.

[0029] The first heat dissipation section, the first heat exchanger, the second heat dissipation section, and the second heat exchanger are alternately distributed. The space above and below the shorter of the first and second heat dissipation sections is utilized by the first and second heat exchangers, respectively. The spaces on both sides of the shorter of the first and second heat dissipation sections are utilized by the first and second connecting pipes, respectively. This layout allows for more efficient use of the heat dissipation cavity space, which is beneficial for reducing the size of power devices.

[0030] In one optional embodiment, the power conversion device further includes a protective cover, a heat dissipation cavity is formed inside the protective cover, and heat dissipation holes are provided on the protective cover. The heat dissipation holes include air inlets and air outlets, one of which is located below the heat sink and the other is located above the heat sink. A fan is provided inside the heat dissipation cavity, and the fan is used to drive the air entering through the air inlets to be discharged from the air outlets.

[0031] With the help of the fan, the air outside the protective cover can enter through the air inlet and exit through the air outlet. The air inlet and air outlet are located on the upper and lower sides of the radiator, respectively, so that the outside air can pass through the radiator fully and improve the heat dissipation effect of the radiator.

[0032] In one optional embodiment, the first heat dissipation part includes a plurality of spaced-apart first condenser tubes, and the second heat dissipation part includes a plurality of spaced-apart second condenser tubes. A plurality of fins are provided between two adjacent first condenser tubes and between two adjacent second condenser tubes. In the first heat dissipation part and the second heat dissipation part, the number of fins provided in the one closer to the air inlet is less than the number of fins provided in the one farther from the air inlet.

[0033] The closer the air is to the air inlet, the lower the air temperature. When the air passes through the section of the first and second heat dissipation parts that is closer to the air inlet, heat exchange occurs, and the air temperature rises after heat exchange. In other words, within the heat dissipation chamber, the closer the air is to the air outlet, the higher the air temperature. The section of the first and second heat dissipation parts that is closer to the air inlet has sparser fins to allow a large amount of air to pass through, while the section that is farther from the air inlet has denser fins to enhance heat dissipation capacity. This allows the vertically arranged first and second heat dissipation parts to dissipate heat evenly.

[0034] In one optional embodiment, the dimension of the first heat dissipation part and the second heat dissipation part that is closer to the air inlet in the first direction is smaller than the dimension of the part that is farther from the air inlet in the first direction.

[0035] By employing an arrangement of varying lengths, more cool air can be directed to the part of the first and second heat dissipation sections that is farther from the air inlet, thereby enhancing the overall heat dissipation capacity of the radiator and balancing the heat dissipation of the first and second heat dissipation sections.

[0036] In one optional 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.

[0037] With the above design, when the first gas-liquid channel is arranged vertically, 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, reducing the possibility of liquid cooling medium remaining in the first heat dissipation part.

[0038] In one optional embodiment, the first power device is fixedly connected to the first substrate by bolts. 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. The head of the bolt abuts against the surface of the first power device away from the first substrate.

[0039] The first power device is fixedly connected to the first substrate, ensuring full contact between them and reducing the possibility of gaps between their contact surfaces. This close contact improves heat dissipation. Furthermore, the bolt head abuts against the first power device rather than the circuit board, minimizing damage to the circuit board during bolt fixing and reducing the impact on the circuit board when connecting the first power device and the first substrate.

[0040] In one alternative embodiment, a portion of the first substrate faces the surface of the partition, and the first substrate blocks at least a partial opening.

[0041] The heat dissipation cavity is connected to the outside world through heat dissipation holes. Impurities from the outside may enter the heat dissipation cavity. If impurities from the heat dissipation cavity enter the power cavity, they will affect the normal operation of the circuit board and its components (e.g., electronic devices). A portion of the first substrate is positioned directly opposite the partition plate, with a partial overlap between the first substrate and the partition plate. In this way, the first substrate can block at least part of the opening, reducing the possibility of gas in the heat dissipation cavity entering the power cavity through the opening. This also reduces the possibility of external impurities affecting the operation of the circuit board and its components, making the power cavity and heat dissipation cavity more independent of each other. A highly protected cavity (i.e., the power cavity) is formed within the power conversion equipment to house the circuit board, which is beneficial to the normal operation of the power conversion equipment.

[0042] In one optional embodiment, the inner wall surface of the first substrate forming the first gas-liquid channel includes a first wall surface and a second wall surface. The first wall surface and the second wall surface are disposed opposite to each other in the thickness direction of the first substrate. A plurality of support members are disposed 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 is connected to or abuts against the second wall surface.

[0043] The first substrate is hollow inside, and the support member serves to support the first and second walls. In other words, the internal cavity of the first substrate is supported by the support member, which reduces the possibility of the first substrate being flattened or bent, thus extending the life of the first substrate and reducing the possibility of the heat sink failing due to local deformation.

[0044] In one optional embodiment, the heat sink further includes a manifold and a return pipe. The manifold is disposed on the side of the first heat sink away from the first substrate, and a manifold channel communicating with the second gas-liquid channel is provided in the manifold. The return pipe is disposed below the first heat sink, with one end of the return pipe communicating with the first gas-liquid channel and the other end communicating with the manifold channel.

[0045] After the cooling medium condenses and dissipates heat in the first heat dissipation section, it gradually reverts to a liquid state. A portion of the liquid cooling medium flows back to the first substrate from the first heat dissipation section, while the remaining liquid coolant flows into the confluence channel of the manifold section, then into the return pipe, and finally back to the first substrate through the return pipe. The first substrate, the first heat dissipation section, the confluence section, and the return pipe are interconnected, reducing the possibility of liquid cooling medium remaining in the first heat dissipation section.

[0046] In one optional embodiment, a first evaporation zone is provided in the first gas-liquid channel. The first evaporation zone is disposed opposite to the first power device. The side of the first evaporation zone facing the first power device is connected to the inner wall of the first substrate. The first gas-liquid channel includes a first chamber and a second chamber located on both sides of the first evaporation zone in the vertical direction. The first evaporation zone is provided with a plurality of first flow channels connecting the first chamber and the second chamber.

[0047] The first power device abuts against the region of the first substrate where the first evaporation zone is formed. Heat from the first power device is transferred to the first evaporation zone through the first substrate. Because the first evaporation zone has multiple first flow channels, the contact area between the first evaporation zone and the cooling medium is increased, thus increasing the number of boiling nucleation points on the first evaporation zone. The cooling medium needs to flow between the first and second chambers through the first flow channels; that is, the cooling medium flows from below the first evaporation zone to above it through the first flow channels. More boiling nucleation points facilitate the transformation of the liquid cooling medium into a gaseous state.

[0048] In one optional embodiment, a second evaporation zone is provided on both sides of the first evaporation zone, the distribution direction of the two second evaporation zones is perpendicular to the vertical direction, and the second evaporation zone is provided with a plurality of second flow channels connecting the first chamber and the second chamber, the number of second flow channels on each second evaporation zone is less than the number of first flow channels.

[0049] Two second evaporation zones are located on either side of the first power device. Multiple second flow channels on the second evaporation zones increase the number of boiling nucleation points, facilitating the change of the cooling medium from liquid to gaseous state as it flows through. Because the second evaporation zones are farther from the first power device than the first evaporation zone, and the number of second flow channels on each second evaporation zone is less than the number of first flow channels, more cooling medium can pass through the first evaporation zone. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the external structure of a power conversion device provided in an embodiment of this application;

[0051] Figure 2 A schematic diagram of the internal chamber of a power conversion device provided in an embodiment of this application;

[0052] Figure 3 This is a schematic diagram of the internal structure of the heat dissipation cavity of the first power conversion device provided in the embodiments of this application;

[0053] Figure 4 A partial exploded view of a power conversion device provided in an embodiment of this application;

[0054] Figure 5 This is a schematic diagram of the internal structure of a heat sink provided in an embodiment of this application;

[0055] Figure 6 for Figure 4 Enlarged view of point A in the middle;

[0056] Figure 7 This is a schematic diagram of the internal structure of another heat sink provided in an embodiment of this application;

[0057] Figure 8 A schematic diagram of a busbar structure provided in an embodiment of this application;

[0058] Figure 9 This is a schematic diagram of another busbar structure provided in an embodiment of this application;

[0059] Figure 10 This is a schematic diagram of the structure of a reflux pipe provided in an embodiment of this application;

[0060] Figure 11 This is a schematic diagram of the structure of a first evaporation zone provided in an embodiment of this application;

[0061] Figure 12 This is a schematic diagram of another first evaporation zone structure provided in an embodiment of this application;

[0062] Figure 13 This is a schematic diagram of the structure of a nut provided in an embodiment of this application;

[0063] Figure 14 This is a schematic diagram of the internal structure of the heat dissipation cavity of the second type of power conversion device provided in the embodiments of this application;

[0064] Figure 15 This is a schematic diagram of the internal structure of the heat dissipation cavity of the third type of power conversion device provided in the embodiments of this application;

[0065] Figure 16 This is a schematic diagram of the internal structure of the heat dissipation cavity of the fourth power conversion device provided in the embodiments of this application;

[0066] Figure 17 A partial exploded view of the fourth power conversion device provided in the embodiments of this application;

[0067] Figure 18 This is a schematic diagram of another heat sink provided in an embodiment of this application;

[0068] Figure 19 This is a schematic diagram of another heat sink provided in an embodiment of this application;

[0069] Figure 20 This is a schematic diagram of the structure of a first connecting pipe and a second connecting pipe provided in an embodiment of this application.

[0070] Figure label:

[0071] 100-Power conversion equipment;

[0072] 1-Housing; 11-Baffle; 111-Power cavity; 112-Heat dissipation cavity; 113-Opening; 114-Mounting port; 12-Protective cover; 121-Heat dissipation hole; 1211-Air inlet; 1212-Air outlet;

[0073] 2-Circuit board; 21-First power device; 211-Bolt; 2111-Head; 2112-Rack; 22-Through hole; 23-Second power device; 24-Inductor; 25-Electronic component;

[0074] 3-Radiator; 31-First substrate; 310-First gas-liquid channel; 311-First wall; 312-Second wall; 313-Support member; 314-First evaporation zone; 3141-First flow channel; 3142-Protrusion; 315-Second evaporation zone; 3151-Second flow channel; 316-First chamber; 317-Second chamber; 32-First heat dissipation part; 320-Second gas-liquid channel; 321-First condenser tube; 3211-Microchannel; 33-Accommodation space; 34-Fin; 35-Merging part; 350-Merging channel; 351-Second plate; 3511-Concave structure; 352-Merging tube; 353-Return tube; 36-Second substrate; 360-Third gas-liquid channel; 37-Second heat dissipation part; 370-Fourth gas-liquid channel; 371-Second condenser tube;

[0075] 4-First heat exchanger; 41-First flat heat dissipation tube; 42-First heat dissipation fin; 43-Heat conduction plate; 44-Heat dissipation fins;

[0076] 5-Second heat exchanger; 51-First flat heat dissipation tube; 22-First heat dissipation fin;

[0077] 6-First connecting pipe; 61-Heat exchange inlet; 7-Second connecting pipe; 71-Heat exchange outlet; 8-Fan. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0079] In this application, unless otherwise expressly specified and limited, the terms "upper" and "lower" and other terms indicating orientation or positional relationship may be defined relative to the orientation in which the components are schematically placed in the accompanying drawings. These directional terms may be relative concepts, used for relative description and clarification, and may change accordingly depending on the orientation of the components in the accompanying drawings. They should not be construed as limitations on this application.

[0080] In this application, the terms "first," "second," etc., are used for descriptive purposes only to distinguish one element from another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0081] In this application, unless otherwise expressly stated and limited, "multiple" means two or more.

[0082] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines or channels, the terms "connection" and "linkage" as used in this application have the meaning of establishing electrical conductivity. The specific meaning needs to be understood in conjunction with the context.

[0083] Furthermore, in this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0084] In the accompanying drawings of the embodiments of this application, solid structures such as parts and components are represented by guide lines; hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with arrows.

[0085] This application provides a power conversion device 100. For example, the power conversion device 100 may be an inverter (e.g., a photovoltaic inverter). This application does not impose specific limitations on the use and function of the power conversion device 100. Figure 1 An exemplary view shows the external structure of the power conversion device 100. Figure 2 An example is shown of the internal chamber of a power conversion device 100.

[0086] Reference Figure 1 and Figure 2 The power conversion device 100 includes a housing 1, which can be a cabinet-like structure (e.g., a server rack), a box-like structure (e.g., a chassis), etc. This application does not specifically limit the shape of the housing 1. The housing 1 includes a partition 11, for example, the partition 11 can be a side wall (or side plate, outer shell plate) on one side of the housing 1, meaning the partition 11 is part of the housing 1. A sealed power cavity 111 is formed inside the housing 1, and an open, ventilated heat dissipation cavity 112 is formed outside the housing 1. The partition 11 is located between the power cavity 111 and the heat dissipation cavity 112; that is, the power cavity 111 is the internal chamber of the housing 1, and the heat dissipation cavity 112 is located outside the housing 1.

[0087] The heat dissipation cavity 112 can be formed by providing a protective cover 12 outside the housing 1, for example, referring to Figure 1 and Figure 2 The power conversion device also includes a protective cover 12, with a heat dissipation cavity 112 formed inside the protective cover 12. The power cavity 111 and the heat dissipation cavity 112 are distributed along a first direction, which is perpendicular to the vertical direction. The protective cover 12 is provided with heat dissipation holes 121 communicating with the internal heat dissipation cavity 112. In some examples, the protective cover 12 can be a hollow structure, and the heat dissipation hole 121 can be a hole in the hollow protective cover 12. (See attached...) Figure 1 and attached Figure 2 In the example, heat dissipation holes 121 are provided in a local area of ​​the protective cover 12. In other examples, heat dissipation holes 121 can be provided in the entire area of ​​each wall of the protective cover 12. This application does not impose any specific restrictions on this.

[0088] Reference Figure 2 The power conversion device 100 also includes a circuit board 2, such as a printed circuit board (PCB). The circuit board 2 is disposed within the power cavity 111, and the circuit board 2 may be arranged parallel to the partition 11. Multiple devices are disposed 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 IP (Ingress Protection) protection level of the power cavity 111 is higher than that of the heat dissipation cavity 112.

[0089] The components disposed on the circuit board 2 can be at least one of chips, resistors, capacitors, diodes, and transistors. Multiple components can be disposed on the same side of the circuit board 2, or a portion of the components can be disposed on the side of the circuit board 2 away from the partition 11. For example, multiple electronic components 25 (including but not limited to capacitors, inductors, relays, etc.) are disposed on the side of the circuit board 2 away from the partition 11, and another portion of the components are disposed on the side of the circuit board 2 closer to the partition 11.

[0090] In this application, multiple components are disposed on both sides of the circuit board 2 as an example. Figure 3 An example of the internal structure of the power conversion device 100 is shown. Figure 4 An exploded view of a partial structure of a power conversion device 100 is shown as an example. (Refer to...) Figure 3 and Figure 4 The partition 11 has an opening 113, which connects the power cavity 111 and the heat dissipation cavity 112. The opening 113 can be square or round, and this application does not limit it.

[0091] A first power device 21 is disposed on the side of circuit board 2 facing opening 113. The first power device 21 can constitute the power conversion circuit of power conversion device 100 to convert the DC power input to power conversion device 100. For example, the first power device 21 can be a chip. In some examples, the first power device 21 can be a device on circuit board 2 that generates significant heat. One end of the first power device 21 connected to circuit board 2 is located inside power cavity 111, and the other end of the first power device 21 facing away from circuit board 2 extends into heat dissipation cavity 112.

[0092] Reference Figure 3 and Figure 4 The power conversion device 100 also includes a heat sink 3, which is disposed in a heat dissipation cavity 112. The heat sink 3 includes a first substrate 31 and a first heat dissipation part 32 connected to the internal cavity. The first substrate 31 protrudes downward toward the first heat dissipation part 32. The first substrate 31 is disposed at the opening 113. The first power device 21 is in contact with the first substrate 31 in the heat dissipation cavity 112. The first heat dissipation part 32 is disposed on the side of the first substrate 31 away from the partition 11.

[0093] Figure 5 The internal structure of the radiator 3 is illustrated exemplarily. A first gas-liquid channel 310 is provided in the first substrate 31, and a second gas-liquid channel 320 communicating with the first gas-liquid channel 310 is provided in the first heat dissipation part 32. The internal cavity of the first substrate 31 is provided with a cooling medium for gas-liquid conversion. The cooling medium can be water or other refrigerants capable of gas-liquid conversion, etc., and this application does not impose specific limitations on it.

[0094] When the first power device 21 heats up, the heat from the first power device 21 is transferred to the first substrate 31, heating the cooling medium inside the first substrate 31. When the liquid cooling medium is heated, at least part of the cooling medium will turn into a gaseous state. The gaseous cooling medium flows into the first heat dissipation section 32, that is, it enters the second gas-liquid channel 320 from the first gas-liquid channel 310. The heat dissipation hole 121 on the housing 1 communicates with the heat dissipation cavity 112 (auxiliary reference). Figure 2 This facilitates heat exchange between the cooling medium within the first heat dissipation section 32 and the external environment. The gaseous cooling medium condenses and dissipates heat within the first heat dissipation section 32, gradually returning to a liquid state. It then flows back from the second gas-liquid channel 320 to the first gas-liquid channel 310 of the first substrate 31, thus continuously cooling the first power device 21. By providing targeted cooling to the first power device 21, the power conversion device 100 can operate stably.

[0095] To effectively dissipate heat, the heat dissipation cavity 112 is connected to the outside through the heat dissipation hole 121. The partition 11 can reduce the possibility of impurities from the heat dissipation cavity 112 or the outside entering the power cavity 111. Furthermore, the first substrate 31 is disposed at the opening 113. Even if the first substrate 31 comes into contact with the first power device 21, it can also block the opening 113, further reducing the possibility of mutual interference between the heat dissipation cavity 112 and the power cavity 111. This allows the circuit board 2 to be placed in the relatively well-protected power cavity 111, ensuring the safety of other devices (e.g., multiple electronic devices 25) while dissipating heat from the first power device 21, and reducing the possibility of malfunction of the power conversion device 100.

[0096] Reference Figure 3 and Figure 4 In one example, the edge of the first substrate 31 faces the surface of the partition 11, and the first substrate 31 blocks the opening 113. In other examples, the side of the first substrate 31 faces the surface of the partition 11, and the first substrate 31 partially blocks the opening 113. It should be noted that when a portion of the surface of the first substrate 31 faces the surface of the partition 11, it means that the first substrate 31 and the partition 11 overlap. In the case of overlap, the first substrate 31 can abut against the partition 11. Even if it does not abut, the overlap between the first substrate 31 and the partition 11 can better block the opening 113, reducing the possibility that gas in the heat dissipation cavity 112 will enter the power cavity 111 through the opening 113. This also reduces the possibility that external impurities will affect the operation of the circuit board 2 and the devices thereon, making the power cavity 111 and the heat dissipation cavity 112 more independent of each other. A highly protected cavity (power cavity 111) is formed in the power conversion device 100 to house the circuit board 2, which is beneficial to the normal operation of the power conversion device 100.

[0097] For better heat dissipation, the first power device 21 is at least partially located below the first heat sink 32. Figure 5 In the example shown, a portion of the first power device 21 extends below the first heat sink 32, and another portion faces the first heat sink 32. The overlap area between the first heat sink 32 and the first power device 21 is small, which allows the first heat sink 32 to have more area to exchange heat with the air in the heat sink cavity 112, which is beneficial to improving the heat dissipation effect of the heat sink 3.

[0098] In other examples, the first power device 21 is located completely below the first heat sink 32, that is, the first power device 21 and the first heat sink 32 are located on opposite sides of the first substrate 31, and the first power device 21 and the first heat sink 32 are spaced apart in the vertical direction, or in other words, the first power device 21 and the first heat sink 32 do not overlap in the first direction.

[0099] Regarding the structure of the first substrate 31, in one example provided in this application, refer to... Figure 4 and Figure 5 The first substrate 31 can be a square plate structure. In other examples, the first substrate 31 can also be a disk shape or other irregularly shaped plate without a clear shape, and this application does not limit this.

[0100] The first heat dissipation part 32 can be any structure capable of condensation. For example, the first heat dissipation part 32 can be a microchannel condenser equipped with heat sinks. Figure 6 for Figure 4 An enlarged view at point A in the middle, refer to Figure 5 and Figure 6 The first heat dissipation section 32 includes a plurality of first condenser tubes 321 spaced apart along the second direction, with the first direction, the second direction, and the vertical direction being perpendicular to each other. Figure 5 In the example shown, each first condenser tube 321 can be a microchannel flat tube, and a plurality of microchannels 3211 in each first condenser tube 321 are arranged in a vertical direction, and each microchannel 3211 extends in a first direction.

[0101] It should be noted that the microchannels 3211 described above can be any channel capable of supplying cooling fluid flow, and this application does not limit the size and structure of the microchannels 3211. Multiple microchannels 3211 in each first condenser tube 321 form the internal chamber of that first condenser tube 321, and the internal chambers of multiple first condenser tubes 321 form the second gas-liquid channel 320 of the first heat dissipation section 32. In other examples, the first condenser tube 321 may not be a plate-shaped tube with multiple internal channels, but rather a plate-shaped tube with a complete internal chamber, or a tortuous pipe; this application does not impose any limitations on this.

[0102] In one example, refer to Figure 6 Multiple fins 34 are provided between each of the two adjacent first condenser tubes 321. In other examples, fins 34 may not be provided.

[0103] After the cooling medium in the first heat dissipation section 32 becomes liquid, it needs to flow back into the first substrate 31. To facilitate the return of the cooling medium in the first heat dissipation section 32 to the first substrate 31, in some examples, refer to Figure 7 , Figure 7 An exemplary embodiment shows another structure of the first heat dissipation part 32, which can be inclined. For example, the included angle α between the first gas-liquid channel 310 and the second gas-liquid channel 320 is greater than 90 degrees and less than 180 degrees, wherein the included angle α can be 95 degrees, 120 degrees, 150 degrees, 170 degrees, etc. As another example, the included angle α between the first gas-liquid channel 310 and the second gas-liquid channel 320 is greater than 90 degrees and less than or equal to 160 degrees, wherein the included angle α can be 110 degrees, 130 degrees, 140 degrees, 160 degrees, etc.

[0104] When the first heat dissipation section 32 needs to be tilted, in an example where the first heat dissipation section 32 includes a plurality of first condenser tubes 321 (e.g., microchannel flat tube structure), the first condenser tubes 321 can be flat tubes similar to parallelogram structures. Each microchannel 3211 is tilted obliquely upward from the first substrate 31 in a first direction so that the liquid in the first heat dissipation section 32 flows back to the first substrate 31, reducing the possibility of liquid cooling medium remaining in the first heat dissipation section 32.

[0105] exist Figure 5 In the example shown, the included angle α between the first gas-liquid channel 310 and the second gas-liquid channel 320 can also be 90 degrees, that is, the first gas-liquid channel 310 and the second gas-liquid channel 320 are perpendicular to each other.

[0106] In addition, to facilitate the return of the cooling working fluid, the radiator 3 may also include a confluence section 35. Figure 5 and Figure 7 The locations of the confluence section 35 are shown in both examples. The confluence section 35 is located on the side of the first heat dissipation section 32 away from the first substrate 31. A confluence channel 350 is provided inside the confluence section 35, and the confluence channel 350 of the confluence section 35 is connected to the second gas-liquid channel 320 of the first heat dissipation section 32. When the cooling medium condenses and dissipates heat in the first heat dissipation section 32, it will gradually turn back into a liquid cooling medium. A portion of the liquid cooling medium will flow directly from the first heat dissipation section 32 back to the first substrate 31 without entering the confluence section 35, while the other portion of the liquid cooling medium will flow into the confluence channel 350 of the confluence section 35, then flow downward from the confluence channel 350, and then flow back to the first substrate 31 through the bottom of the second gas-liquid channel 320.

[0107] Figure 8 An exemplary structure of a busbar 35 is shown, with reference to Figure 8 The confluence section 35 can be formed by connecting the edges of two plates (a first plate and a second plate 351) and bulging internally to form a confluence channel 350. The first plate (obscured by the second plate 351 in the attached diagram and located behind the second plate 351) is connected to the first heat dissipation section 32. The second plate 351 is located on the side of the first plate away from the first heat dissipation section 32, and multiple recessed structures 3511 can be provided on the second plate 351. These recessed structures 3511 are recessed into the confluence channel 350 towards the first plate (auxiliary reference). Figure 7 It is placed inside and abuts against the first plate to provide support, reducing the possibility of the internal chamber of the manifold 35 being crushed and collapsed.

[0108] Figure 9 An exemplary embodiment shows another structure of the busbar 35, in Figure 9 In the example shown, the first heat dissipation section 32 includes a plurality of first condenser tubes 321, and the manifold section 35 includes a plurality of manifolds 352, each manifold 352 communicating with a first condenser tube 321, and the internal space of all manifolds 352 forms a manifold channel 350. In other examples, each manifold 352 is a solid tube.

[0109] Figure 10 An exemplary embodiment shows another structure of the busbar 35, with reference to Figure 10 The manifold 35 is constructed as a hollow plate or hollow box. In this example, a support structure can also be provided inside the manifold channel 350 of the manifold 35. The function of this support structure is the same as... Figure 8 The concave structure 3511 in it serves the same function. This support structure is similar to... Figure 8 The difference between the concave structure 3511 and the concave structure 3511 is that... Figure 8 The concave structure 3511 is formed directly on the second plate 351 during processing by applying local pressure or by other processing methods. Figure 10 The support structure in the example could be set up separately (e.g., welded later). Figure 10 The example shown may also be without a supporting structure.

[0110] In some examples, the heat sink 3 may also include a return pipe 353, to Figure 10 Taking the manifold 35 shown as an example, the return pipe 353 is disposed below the first heat dissipation section 32. One end of the return pipe 353 is connected to the first gas-liquid channel 310 in the first substrate 31, and the other end is connected to the manifold channel 350 in the manifold 35. The positions of the first gas-liquid channel 310 and the manifold channel 350 can be referenced. Figure 5 or Figure 7 Among them, multiple return pipes 353 can be provided and distributed at intervals along the second direction.

[0111] In the above example, after the cooling medium condenses and dissipates heat in the first heat dissipation section 32, it gradually returns to a liquid state. A portion of the liquid cooling medium flows back to the first substrate 31 through the second gas-liquid channel 320 of the first heat dissipation section 32, while another portion flows into the confluence section 35, then enters the return pipe 353 through the confluence channel 350, and finally flows back to the first substrate 31 through the return pipe 353. The first substrate 31, the first heat dissipation section 32, the confluence section 35, and the return pipe 353 are interconnected, reducing the possibility of the liquid cooling medium remaining in the first heat dissipation section 32.

[0112] Furthermore, to facilitate evaporation, the structure of the first substrate 31 can be improved, for example, Figure 11 An exemplary structure of another first substrate 31 is shown, with reference to Figure 11 A first evaporation zone 314 is provided in the first gas-liquid channel 310 of the first substrate 31, and the first evaporation zone 314 is disposed opposite to the first power device 21 (the position of the first power device 21 can be referenced). Figure 5 or Figure 7 The side of the first evaporation belt 314 facing the first power device 21 is connected to the inner wall surface of the first substrate 31. That is, the area of ​​the first substrate 31 where the first evaporation belt 314 is provided is the area of ​​the first substrate 31 that contacts the first power device 21.

[0113] The first gas-liquid channel 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. The first evaporation zone 314 is provided with a plurality of first flow channels 3141 connecting 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 channel 310. Figure 11 In the example shown, the first flow channel 3141 may be a groove formed on the first evaporation zone 314, each groove extending in a vertical direction, so that each first flow channel 3141 extends in a vertical direction, thereby connecting the first chamber 316 and the second chamber 317 distributed in a vertical direction, and the plurality of first flow channels 3141 are spaced apart in a second direction.

[0114] Since the first power device 21 abuts against the area where the first evaporation zone 314 is formed on the first substrate 31, the heat on the first power device 21 is transferred to the first evaporation zone 314 through the first substrate 31. The first evaporation zone 314 has multiple first flow channels 3141, which increases the surface area of ​​the first evaporation zone 314, resulting in a larger contact area between the first evaporation zone 314 and the cooling medium, thus increasing the number of boiling nucleation points on the first evaporation zone 314. The cooling medium needs to flow through the first flow channels 3141 between the first chamber 316 and the second chamber 317; that is, the cooling medium flows from below the first evaporation zone 314 through the first flow channels 3141 into the upper part of the first evaporation zone 314. More boiling nucleation points facilitate the transformation of the liquid cooling medium into a gaseous state.

[0115] In other examples, the first evaporation zone 314 may include a plurality of heat-conducting plates (e.g., fins) spaced apart along a second direction, with a first flow channel 3141 formed between two adjacent heat-conducting plates.

[0116] In other examples, refer to Figure 12 , Figure 12 An exemplary embodiment shows another structure of the first evaporation zone 314, which includes a plurality of matrix-arranged protrusions 3142. Any channel formed by the plurality of matrix-arranged protrusions 3142 that can connect the first chamber 316 and the second chamber 317 is a first flow channel 3141.

[0117] In some examples, refer to Figure 11 and Figure 12 A second evaporation zone 315 is provided on both sides of the first evaporation zone 314, 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 multiple 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 provision of second flow channels 3151 increases the surface area of ​​the second evaporation zone 315, thereby increasing the number of boiling nucleation points. When the cooling medium flows through the second flow channels 3151, it facilitates the change of the cooling medium from a liquid state to a gaseous state.

[0118] The second evaporation zone 315 is farther away from the first power device 21, while the first evaporation zone 314 is closer to the first power device 21. This allows the number of second flow channels 3151 on each second evaporation zone 315 to be less than the number of first flow channels 3141. As a result, more cooling medium passes through the first evaporation zone 314, which is beneficial for the cooling medium to absorb the heat from the first power device 21.

[0119] Since a first gas-liquid channel 310 is provided within the first substrate 31, in order to reduce the possibility of deformation of the first substrate 31, in some examples, refer to Figure 11 and Figure 12 The inner wall surface of the first substrate 31 forming the first gas-liquid channel 310 includes a first wall surface 311 and a second wall surface 312, wherein, Figure 11 and Figure 12 The first wall surface 311 (the wall surface near the first power device 21) is shown only as an example; the second wall surface 312 can be used for auxiliary reference. Figure 5 The first wall surface 311 and the second wall surface 312 are disposed opposite each other in the thickness direction (first direction) of the first substrate 31. A plurality of support members 313 are disposed between the first wall surface 311 and the second wall surface 312. One end of each support member 313 is connected to or abuts against the first wall surface 311, and the other end is connected to or abuts against the second wall surface 312. For example, the two ends of each support member 313 are respectively connected to the first wall surface 311 and the second wall surface 312.

[0120] The support member 313 can be a protrusion (protrusion) or other protruding support structure. The support member 313 plays the role of supporting the first wall surface 311 and the second wall surface 312 between the first wall surface 311 and the second wall surface 312. That is, the internal cavity (first gas-liquid channel 310) of the first substrate 31 is supported by the support member 313, which reduces the possibility of the first substrate 31 being flattened or bent, makes the life of the first substrate 31 longer, and also reduces the possibility of the heat sink 3 failing due to local deformation.

[0121] exist Figure 11 and Figure 12 In the two examples shown, the first chamber 316 has a relatively large space, and multiple supports 313 can be disposed within the first chamber 316. In other examples, for example, in examples where the first evaporation zone 314 and the second evaporation zone 315 are not provided, the supports 313 can be disposed at any suitable location to support the first substrate 31.

[0122] In the example of setting a first evaporation zone 314 and a second evaporation zone 315, the two sides of the first evaporation zone 314 in the first direction can be connected to the first wall surface 311 and the second wall surface 312 respectively, and the two sides of the second evaporation zone 315 in the first direction can also be connected to the first wall surface 311 and the second wall surface 312 respectively.

[0123] To better transfer heat from the first power device 21 to the first substrate 31, the first power device 21 can be fixedly connected to the first substrate 31, ensuring full contact between them and reducing the possibility of gaps appearing between their contact surfaces. For example... Figure 13 An example of a fixed connection method is shown.

[0124] Reference Figure 13The first power device 21 can be fixedly connected to the first substrate 31 by bolts 211. The circuit board 2 is provided with through holes 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 to the first substrate 31. The head 2111 of the bolt 211 abuts against the surface of the first power device 21 facing away from the first substrate 31, allowing the first power device 21 to fit tightly against the first substrate 31. This improves the heat dissipation of the first power device 21. Multiple bolts 211 and corresponding through holes 22 can be provided.

[0125] exist Figure 13 In the example shown, the shank 2112 of the bolt 211 does not extend into or pass through the first gas-liquid channel 310. Furthermore, the head 2111 of the bolt 211 abuts against the first power device 21 rather than the circuit board 2, reducing damage to the circuit board 2 when the bolt 211 is fixed, and minimizing the impact on the circuit board 2 when connecting the first power device 21 and the first substrate 31.

[0126] Since the circuit board 2 is located inside the power cavity 111, when the power conversion device 100 is operating, the circuit board 2 and the components thereon generate significant heat, resulting in a high temperature inside the power cavity 111. Therefore, it is necessary to dissipate heat from the power cavity 111, or in other words, it is necessary to cool the circuit board 2 and the components thereon (e.g., ...). Figure 2 The electronic component 25 in the example dissipates heat. Return to reference. Figure 3 and Figure 4 The power conversion device 100 may also include a first heat exchanger 4, which is used to transfer heat from the power cavity 111 to the heat dissipation cavity 112 to dissipate heat from the electronic device 25.

[0127] In one example, a first heat exchanger 4 is disposed within a heat dissipation cavity 112, and the heat exchange channel within the first heat exchanger 4 is connected to a power cavity 111. A first heat exchange channel (located within the first heat exchanger 4, therefore not shown in the accompanying drawings) is formed within the first heat exchanger 4. The first heat exchange channel is isolated from the heat dissipation cavity 112 and has an inlet and an outlet (obscured, therefore not shown in the accompanying drawings) on the first heat exchanger 4. Both the inlet and outlet of the first heat exchange channel are connected to the power cavity 111. For example, the inlet and outlet of the first heat exchange channel are respectively connected to corresponding mounting ports 114 on the partition 11 to achieve communication between the first heat exchange channel inside the first heat exchanger 4 and the power cavity 111.

[0128] The first heat exchanger 4 allows hot air from the power cavity 111 to enter its first heat exchange channel, where it exchanges heat with the air in the heat dissipation cavity 112. The heat exchanger 3 connects to the outside environment through heat dissipation holes 121, enabling heat exchange between the air in the heat dissipation cavity 112 and the outside environment. In this way, the first heat exchanger 4 can efficiently dissipate heat within the heat dissipation cavity 112, reducing the temperature inside the power cavity 111 and allowing the power conversion device 100 to operate stably.

[0129] Among them, reference Figure 4 The first heat exchanger 4 can be a finned heat exchanger. For example, the first heat exchanger 4 includes a plurality of first flat heat dissipation tubes 41 and a plurality of first heat dissipation fins 42 (e.g., a fin-like structure). The plurality of first flat heat dissipation tubes 41 are spaced apart along a first direction, and a plurality of first heat dissipation fins 42 are disposed between two adjacent first flat heat dissipation tubes 41. The internal space of the plurality of first flat heat dissipation tubes 41 forms 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 can be an "S"-shaped or serpentine channel.

[0130] Reference Figure 3 and Figure 4 The first heat exchanger 4 is at least partially located between the portion of the first substrate 31 protruding from the first heat dissipation portion 32 and the first heat dissipation portion 32. Alternatively, the portion of the first substrate 31 protruding below the first heat dissipation portion 32 and the first heat dissipation portion 32 form a receiving space 33, and the first heat exchanger 4 is at least partially disposed within the receiving space 33. For example, the first heat exchanger 4 is located on the side of the first substrate 31 facing away from the partition 11, and the first heat exchanger 4 is located below the first heat dissipation portion 32. Installing the first heat exchanger 4 within the receiving space 33 allows for a more compact installation of the heat dissipation radiator 3 and the first heat exchanger 4, reducing the space occupied by the heat dissipation cavity 112.

[0131] In some other examples, refer to Figure 14 , Figure 14 An exemplary embodiment shows another configuration of the first heat exchanger 4, which is located inside the power cavity 111. The first heat exchange channel inside the first heat exchanger 4 is isolated from the power cavity 111. The first heat exchange channel has an inlet and an outlet provided on the first heat exchanger 4. The inlet and outlet of the first heat exchange channel are respectively connected to the heat dissipation cavity 112 through the corresponding mounting port 114 on the partition 11.

[0132] With 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, while the heat dissipation cavity 112 is open for ventilation. In this way, outside air can continuously enter the first heat exchange channel of the first heat exchanger 4, reducing the temperature in the power cavity 111 and enabling the power conversion device 100 to operate stably.

[0133] In some other examples, refer to Figure 15 , Figure 15 An exemplary embodiment shows another configuration of the first heat exchanger 4, which is located within a heat dissipation cavity 112. The first heat exchanger 4 includes a heat-conducting plate 43 and a plurality of heat dissipation fins 44 connected to each other. The heat-conducting plate 43 is thermally bonded to the first substrate 31. The plurality of heat dissipation fins 44 are fixed along a second direction on the side of the heat-conducting plate 43 away from the first substrate 31. A fan 8 is provided inside the heat dissipation cavity 112, which is used to generate airflow through the heat dissipation fins 44.

[0134] The temperature of electronic device 25 increases, which in turn increases the temperature of power cavity 111. The heat inside power cavity 111 is transferred to heat-conducting plate 43 through first substrate 31, and then heat-conducting plate 43 transfers the heat to heat dissipation fins 44. Fan 8 blows air towards heat dissipation fins 44, and heat dissipation cavity 112 is open for ventilation, which can blow the heat on heat dissipation fins 44 to the outside of heat dissipation cavity 112 (or outside of protective cover 12), that is, to the outside. The rotation of fan 8 can dissipate heat from heat dissipation fins 44, which is to indirectly dissipate heat from electronic device 25 in power cavity 111.

[0135] In an example where the first substrate 31 protrudes downward toward the first heat sink 32, refer to Figure 15 The heat-conducting plate 43 is thermally bonded to the portion of the first substrate 31 that protrudes from the first heat dissipation part 32, and the heat dissipation fins 44 are located below the first heat dissipation part 32. The first substrate 31 extends downward and forms a space with the first heat dissipation part 32 (which may be...). Figure 4 The first heat exchanger 4 is installed in the receiving space 33, which allows for a more compact installation of the radiator 3 and the first heat exchanger 4, reducing the space occupied by the heat dissipation cavity 112. Furthermore, the first power device 21 contacts the protruding portion of the first substrate 31 (see reference 112). Figure 5 The heat-conducting plate 43 contacts the protruding part of the first substrate 31, and together with the heat dissipation fins 44, it can also help dissipate heat for the first power device 21.

[0136] In some examples, refer to Figure 15The power devices also include inductors 24 (different from the inductors in the aforementioned electronic devices 25) and other devices that generate significant heat. These devices, such as inductors 24, can be housed within the heat dissipation cavity 112 and fixedly connected to the partition 11, which facilitates heat dissipation. The inductors 24 and other devices that generate significant heat can be electrically connected to the circuit board 2 via wires passing through the partition 11. To make efficient use of the space within the heat dissipation cavity 112, the inductor 24 can be positioned above the first substrate 31.

[0137] In addition, to facilitate heat dissipation, in one example, the return... Figure 1 and Figure 2 The power conversion device 100 also includes a fan 8. The heat dissipation hole 121 includes an air inlet 1211 and an air outlet 1212. One of the air inlet 1211 and the air outlet 1212 is located below the heat sink 3, and the other is located above the heat sink 3. That is, the air inlet 1211 and the air outlet 1212 are located on the upper and lower sides of the heat sink 3, respectively. The fan 8 is used to drive the air entering through the air inlet 1211 to be discharged through the air outlet 1212. Under the action of the fan 8, the air outside the protective cover 12 enters through the air inlet 1211, passes through the heat sink 3, and is discharged through the air outlet 1212, so that the outside air can pass through the heat sink 3 fully and improve the heat dissipation effect of the heat sink 3.

[0138] For example, the air inlet 1211 is located below the radiator 3, and the air outlet 1212 is located above the radiator 3. The air temperature in the heat dissipation cavity 112 after heat exchange with the heat exchanger and radiator 3 is relatively high. Since hot air is less dense than cold air, the same volume of hot air is lighter than cold air, causing it to rise. Therefore, placing the air inlet 1211 at the bottom and the air outlet 1212 at the top better conforms to the airflow pattern in the heat dissipation cavity 112, resulting in better heat dissipation.

[0139] Multiple air inlets 1211 and air outlets 1212 can be provided. In some examples, the air inlets 1211 and air outlets 1212 have the same shape and size.

[0140] Figure 16 An example is shown of the internal structure of another power conversion device 100. Figure 17 An example is shown Figure 16 An exploded view of the partial structure of a medium-power conversion device 100. The structure of the housing 1 and the protective shield 12 in this example can be compared with... Figure 1 The structure of the housing 1 shown is the same as that of the protective shield 12. Figure 16 and Figure 17In the example shown, the heat sink 3 includes a first substrate 31 and a first heat dissipation part 32, as well as a second substrate 36 and a second heat dissipation part 37. The second substrate 36 and the first substrate 31 are distributed and fixedly connected in the vertical direction.

[0141] Figure 18 An exemplary illustration shows the internal chambers of the second substrate 36 and the second heat dissipation portion 37, with reference to... Figure 17 and Figure 18 The second substrate 36 has a third gas-liquid channel 360, which contains a cooling medium for gas-liquid conversion. The second heat dissipation unit 37 has a fourth gas-liquid channel 370 that communicates with the third gas-liquid channel 360. The third gas-liquid channel 360 is isolated from the first gas-liquid channel 310; that is, the second substrate 36 and the first substrate 31 are not interconnected. Furthermore, the second heat dissipation unit 37 is located on the side of the second substrate 36 facing away from the partition plate 11.

[0142] Reference Figure 17 In addition to the first power device 21, a second power device 23 is also provided on the side of the circuit board 2 facing the opening 113. In some examples, the second power device 23 can also constitute the power conversion circuit of the power conversion device 100 to convert the DC power input to the power conversion device 100. For example, the second power device 23 can be a chip. In other examples, the second power device 23 can also be a power device on the circuit board 2 that plays other roles. The second power device 23 is in contact with the second substrate 36. When there are many power devices on the circuit board 2 that need heat dissipation, and there is a height difference between different power devices (the first power device 21 and the second power device 23), the second substrate 36 and the second heat dissipation part 37 can better dissipate heat for the second power device 23, reducing the possibility that the normal operation of the power conversion device 100 will be affected by the excessive heat generated by the second power device 23.

[0143] After the first substrate 31 and the second substrate 36 are connected, the opening 113 is sealed, reducing the possibility of air in the heat dissipation cavity 112 entering the power cavity 111. Furthermore, the power cavity 111 (e.g. Figure 16 The heat sink 3 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. This can reduce the size of the heat sink 3 in the first direction, thereby reducing the size of the heat dissipation cavity 112 in the first direction and reducing the size of the power conversion device 100 in the first direction.

[0144] Among them, reference Figure 18The second substrate 36 protrudes downwards from the second heat sink 37, and the second power device 23 is partially located below the second heat sink 37. This reduces the overlap between the second heat sink 37 and the second power device 23, allowing more of the second heat sink 37 to exchange heat with the air in the heat sink cavity 112, thus improving heat dissipation. In other examples, the second power device 23 is completely located below the second heat sink 37; that is, the second power device 23 and the second heat sink 37 are located on opposite sides of the second substrate 36, and there is a vertical distance between them.

[0145] In some examples, refer to Figure 18 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 can also be any other structure that performs the same function as the first substrate 31. Furthermore, the dimensions of the first substrate 31 and the second substrate 36 can be the same or different; this application does not impose specific limitations in this regard. Figures 16 to 18 In the example shown, the first substrate 31 is located above the second substrate 36, and in this example, the first heat sink 32 is also located above the second heat sink 37. In other examples, the first substrate 31 may also be located below the second substrate 36, and in this example, the first heat sink 32 is also located below the second heat sink 37.

[0146] Reference Figure 17 The second heat dissipation section 37 may include a plurality of spaced-apart second condenser tubes 371, and a plurality of fins 34 (similar to) are provided between adjacent second condenser tubes 371. Figure 6 (Structure of the first heat dissipation part 32) In the first heat dissipation part 32 and the second heat dissipation part 37, the number of fins 34 provided in the one closer to the air inlet 1211 is less than the number of fins 34 provided in the one farther from the air inlet 1211.

[0147] Since the air at the air inlet 1211 has just entered the heat dissipation cavity 112 from the outside, the air temperature is lower the closer it is to the air inlet 1211. When the air passes through the one of the first heat dissipation section 32 and the second heat dissipation section 37 that is closer to the air inlet 1211, heat exchange will occur, and the air temperature will rise after heat exchange. That is, in the heat dissipation cavity 112, the closer the air is to the air outlet 1212, the higher the air temperature. The one of the first heat dissipation section 32 and the second heat dissipation section 37 that is closer to the air inlet 1211 has sparser fins 34, so that a large amount of air can pass through and more air is blown to the one that is farther away. The one that is farther away from the air inlet 1211 has denser secondary fins 34 to enhance the heat dissipation capacity, so that the vertically arranged first heat dissipation section 32 and second heat dissipation section 37 can dissipate heat evenly.

[0148] Reference Figure 16 and Figure 17Taking the example where the air inlet 1211 is located below the radiator 3, if the first heat dissipation part 32 is located above the second heat dissipation part 37, then 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 where the air inlet 1211 is located above the radiator 3, if the first heat dissipation part 32 is located above the second heat dissipation part 37, then 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.

[0149] In some other examples, refer to Figure 19 , Figure 19 An exemplary embodiment shows another arrangement of the first heat dissipation section 32 and the second heat dissipation section 37. In this example, the dimension of the first heat dissipation section 32 and the second heat dissipation section 37 closer to the air inlet 1211 in the first direction is smaller than the dimension of the second heat dissipation section farther from the air inlet 1211 in the first direction. That is, the heat dissipation section closer to the air inlet 1211 is shorter in the first direction. By adopting an arrangement of different lengths, more cool air can be blown to the first heat dissipation section 32 and the second heat dissipation section 37 farther from the air inlet 1211, thereby enhancing the heat dissipation capacity of the radiator 3 and enabling the vertically arranged first heat dissipation section 32 and the second heat dissipation section 37 to dissipate heat evenly.

[0150] exist Figure 19 In the example shown, fins 34 may not be provided, or fins 34 may be provided in the first heat dissipation part 32 and the second heat dissipation part 37. The density of fins 34 in the first heat dissipation part 32 and the second heat dissipation part 37 may be set according to the distance from the air inlet hole 1211, which will not be elaborated here.

[0151] Return to reference Figure 16 and Figure 17 In addition to the first heat exchanger 4, the power conversion device 100 also includes a second heat exchanger 5 disposed within the heat dissipation cavity 112. The second heat exchanger 5 is used to transfer heat from the power cavity 111 to the heat dissipation cavity 112 to dissipate heat from the electronic device 25. For example, a second heat exchange channel (not shown in the figure because it is located inside the second heat exchanger 5) is provided inside the second heat exchanger 5. The second heat exchange channel is connected to the power cavity 111 (located inside 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 inside the power cavity 111 and enabling the power conversion device 100 to operate stably.

[0152] Reference Figure 16Since the first substrate 31 protrudes downwards from the first heat dissipation part 32 and the second substrate 36 extends downwards from the second heat dissipation part 37, there is ample space below both 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 disposed between the first heat dissipation part 32 and the second heat dissipation part 37, and the other is located below the one with the lower height of the first heat dissipation part 32 and the second heat dissipation part 37.

[0153] In other words, when the first heat exchanger 4 and the second heat exchanger 5 are installed, the extra space below the first heat dissipation part 32 and the second heat dissipation part 37 is fully utilized, making the installation of the radiator 3, the first heat exchanger 4 and the second heat exchanger 5 more compact. The space in the vertical direction of the heat dissipation cavity 112 is fully utilized, reducing the size of the power conversion device 100 in the first direction.

[0154] For example, in Figure 16 In the example shown, the first heat dissipation part 32 is located above the second heat dissipation part 37, and the receiving space 33 is located between the first heat dissipation part 32 and the second heat dissipation part 37 (auxiliary reference). Figure 17 In one embodiment, the first heat exchanger 4 is disposed between the first heat dissipation section 32 and the second heat dissipation section 37, and the second heat exchanger 5 is disposed below the second heat dissipation section 37. In other embodiments, the first heat dissipation section 32 is located below the second heat dissipation section 37, in which case the second heat exchanger 5 is disposed between the first heat dissipation section 32 and the second heat dissipation section 37, and the first heat exchanger 4 is disposed below the first heat dissipation section 32.

[0155] In one example, 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. Figure 20 This structure is illustrated as an example, see reference. Figure 20 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 connected to 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 connected to the second connecting pipe 7. The first connecting pipe 6 and the second connecting pipe 7 are both connected to the power cavity 111.

[0156] The first heat exchanger 4 and the second heat exchanger 5 are interconnected and fixed together by the first connecting pipe 6 and the second connecting pipe 7, which improves the integration of the first heat exchanger 4 and the second heat exchanger 5. It eliminates the need to install the first heat exchanger 4 and the second heat exchanger 5 separately and connect them to the power cavity 111 separately, which is beneficial for the unified assembly and disassembly of the first heat exchanger 4 and the second heat exchanger 5 in the heat dissipation cavity 112.

[0157] 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 connected to the corresponding mounting ports 114 on the partition plate 11 (refer to reference). Figure 17This allows for the connection between the heat exchange channels inside the first heat exchanger 4 and the second heat exchanger 5 and the power cavity 111. 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. After exchanging heat with the air in the heat dissipation cavity 112, the hot air in the first heat exchanger 4 and the second heat exchanger 5 enters the second connecting pipe 7 and then the power cavity 111.

[0158] In one example, refer to Figure 16 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. The first connecting pipe 6 and the second connecting pipe 7 are respectively located on different sides of the lower of the first heat dissipation section 32 and the second heat dissipation section 37 in the second direction. For example, in Figure 16 In the example shown, 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.

[0159] With the above design, 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 lower one of the first heat dissipation part 32 and the second heat dissipation part 37 is utilized by the first heat exchanger 4 and the second heat exchanger 5, respectively. The space on both sides of the lower one of the first heat dissipation part 32 and the second heat dissipation part 37 is utilized by the first connecting pipe 6 and the second connecting pipe 7, respectively. This can make fuller use of the space of the heat dissipation cavity 112 and reduce the volume of the power conversion device 100.

[0160] In one example, refer to Figure 20 The second heat exchanger 5 can be a finned heat exchanger. For example, the second heat exchanger 5 includes a plurality of second flat heat dissipation tubes 51 and a plurality of second heat dissipation fins 52 (e.g., a fin-like structure). The plurality of second flat heat dissipation tubes 51 are spaced apart along a first direction, and a plurality of second heat dissipation fins 52 are arranged between each pair of adjacent second flat heat dissipation tubes 51. The internal space of the plurality of second flat heat dissipation tubes 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 can be an "S"-shaped channel or a serpentine channel.

[0161] In some examples, to facilitate the flow of air within the power cavity 111 in the first heat exchanger 4 and the second heat exchanger 5, a drive fan (not shown in the figures) can be provided within the power cavity 111 to drive the airflow.

[0162] In some examples, the first substrate 31 and the second substrate 36 can be integrally connected, while in other examples, the first substrate 31 and the second substrate 36 can be separately disposed and then fixedly connected to each other (directly fixed or indirectly fixed through other structures).

[0163] In some examples, the first heat exchanger 4 can be separately disposed from the first substrate 31 and then separately installed in the heat dissipation cavity 112. In other examples, the first heat exchanger 4 can be integrally connected to the first substrate 31.

[0164] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power conversion device, characterized in that, Includes housing, circuit board, radiator, and first heat exchanger. A sealed power cavity is formed inside the housing, and an open and ventilated heat dissipation cavity is formed outside the housing. The housing includes a partition 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 provided on the partition. A circuit board is disposed inside the power cavity. A first power device is mounted on the side of the circuit board facing the opening. The first power device constitutes the power conversion circuit of the power conversion device to perform power conversion on the DC power input to the power conversion device. The heat sink is disposed within the heat dissipation cavity and includes a first substrate and a first heat dissipation portion. The first substrate is disposed at the opening and makes thermally conductive contact with the first power device within the heat dissipation cavity. The first heat dissipation portion extends outward from the first substrate, and the first substrate protrudes downward from the first heat dissipation portion. The first power device makes thermally conductive contact with the portion of the first substrate protruding downward from the first heat dissipation portion, and the first power device is at least partially located below the first heat dissipation portion. A first gas-liquid channel is disposed within the first substrate, and the first gas-liquid channel includes a plurality of first flow channels. The plurality of first flow channels are at least partially located in the portion of the first substrate protruding downward from the first heat dissipation portion, and the plurality of first flow channels are disposed opposite to the first power device. A second gas-liquid channel is disposed within the first heat dissipation portion and communicates with the first gas-liquid channel. A cooling medium for gas-liquid conversion is disposed within the first gas-liquid channel, and the plurality of first flow channels are used to transport the cooling medium to the second gas-liquid channel. 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 has electronic components mounted on the side opposite to where the first power device is mounted. The first heat exchanger is located in the power cavity or the heat dissipation cavity. The first heat exchanger is used to transfer heat from the power cavity to the heat dissipation cavity to dissipate heat from the electronic components.

2. The power conversion device according to claim 1, characterized in that, The first heat exchanger is located inside the power cavity, and a first heat exchange channel is formed inside the first heat exchanger. The first heat exchange channel is isolated from the power cavity. The first heat exchange channel has an inlet and an outlet provided on the first heat exchanger, and both the inlet and outlet of the first heat exchange channel are connected to the heat dissipation cavity.

3. The power conversion device according to claim 1, characterized in that, The first heat exchanger is located inside the heat dissipation cavity. A first heat exchange channel is formed inside the first heat exchanger. The first heat exchange channel is isolated from the heat dissipation cavity. The first heat exchange channel has an inlet and an outlet provided on the first heat exchanger. Both the inlet and outlet of the first heat exchange channel are connected to the power cavity.

4. The power conversion device according to claim 3, characterized in that, The first heat exchanger is at least partially located between the portion of the first substrate that protrudes from the first heat dissipation portion and the first heat dissipation portion.

5. The power conversion device according to claim 1, characterized in that, The first heat exchanger is located inside the heat dissipation cavity. The first heat exchanger includes a heat-conducting plate and heat dissipation fins connected to each other. The heat-conducting plate is thermally bonded to the first substrate. A fan is provided inside the heat dissipation cavity. The fan is used to generate airflow through the heat dissipation fins.

6. The power conversion device according to claim 5, characterized in that, The first substrate protrudes downward toward the first heat dissipation part, the heat-conducting plate is thermally bonded to the portion of the first substrate that protrudes from the first heat dissipation part, and the heat dissipation fins are located below the first heat dissipation part.

7. The power conversion device according to claim 1, characterized in that, The power cavity and the heat dissipation cavity are distributed along a first direction, which is perpendicular to the vertical direction. The heat sink further includes a second substrate and a second heat dissipation part. The second substrate and the first substrate are distributed along the vertical direction and fixedly connected. The second heat dissipation part extends outward from the second substrate. A third gas-liquid channel is provided in the second substrate. A fourth gas-liquid channel communicating with the third gas-liquid channel is provided in the second heat dissipation part. The third gas-liquid channel is isolated from the first gas-liquid channel. A second power device is provided on the side of the circuit board facing the opening. The second power device is in contact with the second substrate in the heat dissipation cavity. A cooling medium for gas-liquid conversion is provided in the third gas-liquid channel.

8. The power conversion device according to claim 7, characterized in that, The power conversion device further includes a second heat exchanger, which is used to transfer heat from the power cavity to the heat dissipation cavity. Both the first heat exchanger and the second heat exchanger are disposed within the heat dissipation cavity. The first heat dissipation part and the second heat dissipation part are distributed in a vertical direction. The first substrate protrudes downward toward the first heat dissipation part, and the second substrate protrudes downward toward 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 the lower height of the first heat dissipation part and the second heat dissipation part.

9. The power conversion device according to claim 8, characterized in that, A first heat exchange channel is formed in the first heat exchanger, and a second heat exchange channel is formed in the second heat exchanger. The inlet of the first heat exchange channel and the inlet of the second heat exchange channel are both connected to a first connecting pipe. The outlet of the first heat exchange channel and the outlet of the heat exchange channel are both connected to a second connecting pipe. The first connecting pipe and the second connecting pipe are both located in the heat dissipation cavity and are both connected to the power cavity.

10. The power conversion device according to claim 9, characterized in that, Both 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 respectively located on different sides of the lower 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.

11. The power conversion device according to any one of claims 7-10, characterized in that, The power conversion device also includes a protective cover, the heat dissipation cavity is formed inside the protective cover, the protective cover is provided with heat dissipation holes, the heat dissipation holes include air inlets and air outlets, one of the air inlets and the air outlets is located below the heat sink, and the other is located above the heat sink. A fan is provided inside the heat dissipation cavity, and the fan is used to drive the air entering through the air inlets to be discharged from the air outlets.

12. The power conversion device according to claim 11, characterized in that, The first heat dissipation section includes a plurality of spaced-apart first condenser tubes, and the second heat dissipation section includes a plurality of spaced-apart second condenser tubes. Multiple fins are provided between adjacent first condenser tubes and between adjacent second condenser tubes. In the first heat dissipation section and the second heat dissipation section, the number of fins provided in the section closer to the air inlet is less than the number of fins provided in the section farther from the air inlet.

13. The power conversion device according to claim 11, characterized in that, In the first heat dissipation part and the second heat dissipation part, the dimension of the one closer to the air inlet in the first direction is smaller than the dimension of the one farther from the air inlet in the first direction.

14. The power conversion device according to any one of claims 1-10, characterized in that, The 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.

15. The power conversion device according to any one of claims 1-10, characterized in that, The first power device is fixedly connected to the first substrate by bolts. 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. The head of the bolt abuts against the surface of the first power device that is away from the first substrate.

16. The power conversion device according to any one of claims 1-10, characterized in that, The inner wall surface of the first substrate forming the first gas-liquid channel includes a first wall surface and a second wall surface. The first wall surface and the second wall surface are disposed opposite each other in the thickness direction of the first substrate. A plurality of support members are disposed 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 is connected to or abuts against the second wall surface.

17. The power conversion device according to any one of claims 1-10, characterized in that, The heat sink further includes a manifold and a return pipe. The manifold is disposed on the side of the first heat sink away from the first substrate. The manifold is provided with a manifold channel communicating with the second gas-liquid channel. The return pipe is disposed below the first heat sink. One end of the return pipe is connected to the first gas-liquid channel, and the other end is connected to the manifold channel.

18. The power conversion device according to any one of claims 1-10, characterized in that, The first gas-liquid channel is provided with a first evaporation zone, which is disposed opposite to the first power device. The side of the first evaporation zone facing the first power device is connected to the inner wall of the first substrate. The first gas-liquid channel includes a first chamber and a second chamber located on both sides of the first evaporation zone in the vertical direction. The first evaporation zone is provided with a plurality of first flow channels connecting the first chamber and the second chamber.

19. The power conversion device according to claim 18, characterized in that, A second evaporation zone is provided on both sides of the first evaporation zone. The distribution direction of the two second evaporation zones is perpendicular to the vertical direction. The second evaporation zone is provided with a plurality of second flow channels connecting the first chamber and the second chamber. The number of second flow channels on each second evaporation zone is less than the number of first flow channels.

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