Heat dissipation assembly and power conversion device

Abstract

The present application provides a heat dissipation assembly and a power conversion device. The power conversion device comprises a housing, power devices, and the heat dissipation assembly. The housing comprises a first cavity and a second cavity spaced apart in a first direction. The housing is provided with an air inlet hole and an air outlet hole which are communicated with the second cavity. The power devices are accommodated in the first cavity. A heat dissipation assembly comprises the heat dissipation device and a working medium pump which are accommodated in the second cavity. The heat dissipation device comprises a heat dissipation substrate, a plurality of flat condensation tubes, and a communication portion. The heat dissipation substrate comprises a first chamber and a second chamber obtained by division by means of a partition portion. In the first direction, the first chamber is located on the side of the second chamber close to the power devices. The top of the partition portion is provided with a through hole communicated with the first chamber and the second chamber. The plurality of flat condensation tubes are communicated with each other by means of the communication portion, are communicated with the second chamber, and are located between the air inlet hole and the air outlet hole. The first chamber, the second chamber, and the flat condensation tubes are all used for accommodating a cooling working medium. The working medium pump is used for driving the cooling working medium to flow to the first chamber. The present invention facilitates miniaturization.

Description

Heat dissipation assembly and power conversion device

[0001] The present application claims priority from the Chinese patent application No. 202411357833.3 filed on September 26, 2024, and entitled "Heat dissipation assembly and power conversion device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of electronic technology, and in particular, to a heat dissipation assembly and a power conversion device. BACKGROUND

[0003] In the existing power conversion device, the power device is accommodated in the first cavity of the shell, the evaporator and the condenser are accommodated in the second cavity of the shell, and the evaporator and the condenser are connected through the pipeline. The evaporator accommodates the cooling working medium. The heat generated by the power device during operation can be transferred to the cooling working medium in the evaporator, the cooling working medium absorbs heat and boils to form cooling working medium in a gaseous state, the cooling working medium in a gaseous state is transferred to the condenser to release heat and condense, and the cooling working medium in a liquid state in the condenser flows back to the evaporator, thereby realizing heat dissipation of the power device through the gas-liquid two-phase circulation of the cooling working medium. However, the existing power conversion device realizes the gas-liquid two-phase conversion of the cooling working medium through gravity, which requires the condenser to be higher than the evaporator and the power device, and the evaporator and the condenser occupy a large volume, resulting in low space utilization of the power conversion device and being not conducive to the miniaturization design of the power conversion device. SUMMARY

[0004] The present application provides a heat dissipation assembly and a power conversion device, which aims to solve the problem that the power conversion device is not conducive to miniaturization design.

[0005] In a first aspect, the embodiments of the present application provide a power conversion device. The power conversion device comprises a housing, a power device, and a heat dissipation assembly. The housing comprises a first cavity and a second cavity, the first cavity and the second cavity are arranged apart in a first direction, the housing is provided with a connecting hole, an air inlet hole, and an air outlet hole, the connecting hole is in communication with the first cavity and the second cavity, the air inlet hole and the air outlet hole are both in communication with the second cavity, and the first direction is different from the direction of gravity. The power device is accommodated in the first cavity. The heat dissipation assembly comprises a heat sink and a working medium pump, the heat sink is accommodated in the second cavity, and the heat sink comprises a heat dissipation substrate, a plurality of condensation flat tubes, and a communication part. The heat dissipation substrate is in contact with the power device through the connecting hole and covers the connecting hole to close the first cavity. The heat dissipation substrate comprises a first chamber and a second chamber divided by a partition, the first chamber is located on the side of the second chamber close to the power device in the first direction. In the direction of gravity, the top of the partition is provided with a through hole, the first chamber is in communication with the second chamber through the through hole. The plurality of condensation flat tubes are arranged apart on the side of the heat dissipation substrate away from the power device, the plurality of condensation flat tubes are in communication with each other through the communication part, and the second chamber is in communication with the plurality of condensation flat tubes. The condensation flat tube is located between the air inlet hole and the air outlet hole. The first chamber, the second chamber, and the condensation flat tube are all used to accommodate cooling working medium for gas-liquid two-phase conversion, and the working medium pump is used to drive the cooling working medium in liquid state to flow to the first chamber.

[0006] In the above implementation, the heat generated by the power device during operation is transferred to the heat sink, and external air flow can flow into the second cavity from the air inlet, and then flow out of the second cavity from the air outlet through the heat sink, thereby achieving heat dissipation of the power device. The heat generated by the power device during operation is transferred to the cooling working medium in the liquid state in the first chamber, the cooling working medium absorbs heat and boils to form the cooling working medium in the gaseous state, the cooling working medium in the gaseous state is guided from the first chamber to the second chamber through the through hole at the top, and then flows to the connecting part through the plurality of condensation flat tubes. The cooling working medium in the gaseous state releases heat and condenses to form the cooling working medium in the liquid state, and the cooling working medium in the liquid state accumulates in the first chamber, the condensation flat tube and the connecting part under the action of gravity. The heat transferred from the power device to the cooling working medium can be transferred to the external environment through the air flow flowing through the heat sink, thereby achieving heat dissipation of the power device through the gas-liquid two-phase conversion of the cooling working medium. In the embodiment of the present application, the working medium pump can recycle the cooling working medium to ensure that the cooling working medium in the liquid state in the first chamber always has sufficient amount. In combination with the separation part, the first chamber for evaporation is isolated from other chambers, and the working medium pump can drive the cooling working medium in the liquid state from the second chamber or the connecting part to the first chamber through the working medium pump, so that the liquid level of the cooling working medium in the liquid state in the first chamber and the second chamber is controlled by the working medium pump. That is, the parameters of the working medium pump can be set according to the needs, so that the liquid level of the cooling working medium in the liquid state in the first chamber can meet the product needs. For example, when there are more power devices, the liquid level of the cooling working medium in the liquid state in the first chamber can be higher, and the liquid level of the cooling working medium in the liquid state in the first chamber can be lower, so that more power devices can be attached to the heat dissipation substrate and cooled by the cooling working medium in the first chamber. The liquid level refers to the height of the liquid medium surface in the equipment and the container.

[0007] Compared with the prior art, the present application integrates the functions of the evaporator and the condenser through the heat sink, which can avoid setting complex pipelines between the evaporator and the condenser by welding or bonding, is conducive to reducing the structural complexity of the heat sink, improving the structural stability and reliability of the heat sink, and reducing the volume of the heat sink. Moreover, the design of the present application combines gravity and the working medium pump to realize the gas-liquid two-phase conversion of the cooling working medium and the recycling of the cooling working medium, which is conducive to reducing the influence of gravity on the design of the heat sink, the bottom wall of the second chamber can be not higher than the bottom wall of the first chamber, the position of the power device can not be considered when setting the second chamber, and the bottom wall of the second chamber can be not higher than the power device, which is conducive to reducing the volume of the heat sink and improving the space utilization of the power conversion device. In addition, it is also convenient for the power device to be arranged more flexibly, as long as the liquid level of the first chamber can cover the power device by adjusting the working medium pump.

[0008] Further, since the working medium pump only needs to overcome the flow resistance of the cooling working medium in liquid state flowing from the second chamber or the communication portion to the first chamber through the working medium pump, the pressure head and service life requirement of the working medium pump is low, the processing cost of the working medium pump is low, which is conducive to reducing the heat dissipation cost, reducing the processing cost of the power conversion device, improving the speed of the gas-liquid two-phase conversion of the cooling working medium, and improving the heat dissipation efficiency of the power device.

[0009] In a possible implementation, in the gravity direction, the liquid level of the cooling working medium in liquid state in the first chamber is higher than the power device.

[0010] In the implementation, the design that the liquid level of the cooling working medium in liquid state in the first chamber is higher than the power device is conducive to improving the efficiency of heat generated by the power device during operation being transferred to the cooling working medium in liquid state in the first chamber, and improving the heat dissipation efficiency of the power device.

[0011] In a possible implementation, in the gravity direction, the liquid level of the cooling working medium in liquid state in the first chamber is higher than the cooling working medium in liquid state in the second chamber.

[0012] In the implementation, the working medium pump can drive more liquid working medium to flow to the first chamber, so that the liquid working medium in the first chamber is higher, thereby covering more power devices, so that more power devices contact the heat dissipation substrate and are cooled through the heat sink, thereby reducing the volume of the power converter and improving the heat dissipation efficiency.

[0013] In a possible implementation, in the gravity direction, the projection of the through hole in the first direction is located above the projection of the power device in the first direction.

[0014] In the implementation, in the gravity direction, the projection of the through hole in the first direction is located above the projection of the power device in the first direction, which avoids the situation that the cooling working medium in liquid state in the first chamber flows from the through hole to the second chamber during driving the liquid level of the cooling working medium in liquid state in the first chamber to be higher than the power device, and is conducive to reducing the difficulty of driving the liquid level of the cooling working medium in liquid state in the first chamber to be higher than the power device, and improving the heat dissipation efficiency of the power device.

[0015] In a possible implementation, the working medium pump is located outside the heat sink, and the working medium pump includes an inlet and an outlet. The power conversion device further includes an input pipe body and an output pipe body. The inlet of the working medium pump is in communication with the second chamber or the communication portion through the input pipe body, and the outlet of the working medium pump is in communication with the first chamber through the output pipe body.

[0016] In the implementation solution, the working medium pump is located outside the heat sink, the inlet of the working medium pump is communicated with the second chamber or the communication portion through the input pipe body, and the outlet of the working medium pump is communicated with the first chamber through the output pipe body. The design facilitates maintenance and replacement of the working medium pump, reduces maintenance cost of the heat sink, and reduces maintenance cost of the power conversion device.

[0017] The design that the inlet of the working medium pump is communicated with the second chamber through the input pipe body facilitates reduction of structural complexity and length of the input pipe body, reduction of material cost of the heat sink, reduction of structural complexity of the heat sink, improvement of structural reliability of the heat sink, improvement of efficiency of the cooling working medium flowing from the second chamber to the first chamber through the working medium pump, and improvement of heat dissipation efficiency of the power device.

[0018] In addition, the power conversion device can be installed on various bearing surfaces, and the design that the inlet of the working medium pump is communicated with the second chamber or the communication portion through the input pipe body can adapt to various installation scenarios of the power conversion device.

[0019] When the power conversion device is installed on a bearing surface (for example, is hung on a wall surface perpendicular to a horizontal surface), the first direction is perpendicular to the direction of gravity, and under the action of gravity, the cooling working medium in a liquid state formed by heat dissipation and condensation can be accumulated at the bottom of the second chamber and has a large amount at the bottom of the second chamber. In this case, the working medium pump can stably drive the cooling working medium in a liquid state from the second chamber to the first chamber through the working medium pump through the input pipe body communicated with the second chamber, and the reliability and stability of heat dissipation of the power device are improved.

[0020] When the power conversion device is installed on a bearing surface (for example, is hung on a wall surface inclined to a horizontal surface), the second chamber is located below the communication portion in the direction of gravity, and under the action of gravity, the cooling working medium in a liquid state formed by heat dissipation and condensation can be accumulated at the bottom of the second chamber and has a large amount at the bottom of the second chamber. In this case, the working medium pump can stably drive the cooling working medium in a liquid state from the second chamber to the first chamber through the working medium pump through the input pipe body communicated with the second chamber, and the reliability and stability of heat dissipation of the power device are improved.

[0021] When the power conversion device is installed on a bearing surface (for example, is hung on a wall surface inclined to a horizontal surface), the second chamber is located above the communication portion in the direction of gravity, the first direction is inclined to the horizontal surface, and the included angle between the first direction and the horizontal surface is less than 30°, under the action of gravity, the cooling working medium in a liquid state formed by heat dissipation and condensation can be accumulated at the bottom of the second chamber and has a large amount at the bottom of the second chamber. In this case, the working medium pump can stably drive the cooling working medium in a liquid state from the second chamber to the first chamber through the working medium pump through the input pipe body communicated with the second chamber, and the reliability and stability of heat dissipation of the power device are improved.

[0022] When the power conversion device is installed on a bearing surface (for example, hung on a wall surface inclined to the horizontal surface), and the second chamber is located above the communication portion in the direction of gravity, under the action of gravity, the cooling working medium in liquid state formed by heat release condensation is accumulated at the bottom of the communication portion, and a larger amount is stored at the bottom of the communication portion. In this case, the working medium pump can stably drive the cooling working medium in liquid state from the communication portion to the first chamber through the working medium pump via the input pipe body in communication with the communication portion, which is conducive to improving the reliability and stability of heat dissipation of the power device.

[0023] In a possible implementation, the heat sink is further provided with an input pipe body mounting hole and an output pipe body mounting hole, the input pipe body mounting hole is located below the second chamber or the communication portion in the direction of gravity, the output pipe body mounting hole is located below the first chamber in the direction of gravity, the working medium pump is located below the heat sink, the input pipe body is inserted into the input pipe body mounting hole, and the output pipe body is inserted into the output pipe body mounting hole.

[0024] In the implementation, since the cooling working medium in liquid state formed by heat release condensation is accumulated at the bottom of the first chamber, the bottom of the second chamber, the bottom of the condensation flat tube, and the bottom of the communication portion under the action of gravity, and the working medium pump is located below the heat sink, the structural complexity and length of the input pipe body in communication with the second chamber (or the communication portion) and the inlet of the working medium pump are reduced, the structural complexity and length of the output pipe body in communication with the first chamber and the outlet of the working medium pump are reduced, the material cost of the heat sink is reduced, the structural complexity of the heat sink is reduced, and the structural reliability of the heat sink is improved.

[0025] In a possible implementation, the bottom of the partition portion is further provided with a mounting hole in the direction of gravity, the mounting hole is in communication with the first chamber and the second chamber, and the working medium pump is accommodated in the mounting hole.

[0026] In the implementation, the working medium pump is accommodated in the mounting hole, the working medium pump is integrated in the heat sink, the working medium pump and the heat sink are connected through a pipeline, the structural reliability between the working medium pump and the heat sink is improved, the difficulty of accommodating the heat sink and the working medium pump in the second chamber is reduced, the space utilization of the second chamber is improved, and the processing cost of the power conversion device is reduced.

[0027] In a possible implementation, the communication portion includes a flow-through cavity, the communication portion is located on the side of the plurality of condensation flat tubes away from the heat dissipation substrate, the communication portion is fixedly connected with the plurality of condensation flat tubes, and the flow-through cavity is in communication with the plurality of condensation flat tubes.

[0028] In the implementation scheme, the plurality of condensing flat tubes are connected to each other through the flow passage. The connecting part is located on the side of the plurality of condensing flat tubes away from the heat dissipation base plate. The connecting part is fixedly connected to the plurality of condensing flat tubes, which is beneficial to improve the stability of the plurality of condensing flat tubes arranged at intervals, and is beneficial to improve the structural stability and reliability of the heat dissipation device.

[0029] In a possible implementation, the plurality of condensing flat tubes are arranged at intervals along the second direction to form the ventilation hole, and the second direction is perpendicular to the first direction and the direction of gravity.

[0030] In the implementation scheme, the external airflow can flow into the second cavity through the air inlet hole, flow through the plurality of condensing flat tubes through the ventilation hole, and flow out of the second cavity through the air outlet hole to transfer the heat generated by the power device during operation to the external environment. The plurality of condensing flat tubes are arranged at intervals along the second direction to form the ventilation hole, which is beneficial to increase the contact area of the plurality of condensing flat tubes and the external airflow, and is beneficial to improve the heat dissipation efficiency of the power device. Moreover, the structure is simple and stable, and is convenient for design, which is beneficial to reduce the processing cost of the heat dissipation device.

[0031] In a possible implementation, in the direction of gravity, the plurality of condensing flat tubes are located between the air inlet hole and the air outlet hole.

[0032] In the implementation scheme, in the direction of gravity, the plurality of condensing flat tubes are located between the air inlet hole and the air outlet hole, which is beneficial to reduce the flow resistance of the external airflow flowing into the second cavity through the air inlet hole and flowing through the plurality of condensing flat tubes through the ventilation hole, and is beneficial to improve the heat dissipation efficiency of the plurality of condensing flat tubes and the heat dissipation efficiency of the power device.

[0033] In a possible implementation, a heat dissipation fin is further arranged between the two adjacent condensing flat tubes, and the heat dissipation fin is in contact with and fixedly connected to the two adjacent condensing flat tubes.

[0034] In the implementation scheme, the external airflow can flow through the heat dissipation shell through the ventilation hole between the two adjacent condensing flat tubes to transfer the heat generated by the power device during operation to the external environment, thereby achieving heat dissipation of the power device. The design of the heat dissipation fin is beneficial to increase the contact area of the condensing flat tube and the external airflow, and is beneficial to improve the heat dissipation efficiency of the condensing flat tube and the heat dissipation efficiency of the power device.

[0035] In a possible implementation, each condensing flat tube includes a plurality of flow channels extending along the first direction, and the adjacent flow channels are isolated by a baffle. The plurality of flow channels are in communication with the second cavity and the connecting part.

[0036] In the implementation solution, the gaseous working medium is evenly dispersed in the flow channels, the baffle can bear a certain pressure, the bulging problem is avoided, the stability of the condenser flat tube is better, and the structural stability and reliability of the radiator are improved.

[0037] In a possible implementation, the second chamber further comprises a reinforcing portion, so that the second chamber is divided into a first sub-chamber and a second sub-chamber, and the first sub-chamber is located above the second sub-chamber in the direction of gravity. The first sub-chamber is in communication with the first chamber through the through hole. The first sub-chamber is in communication with the communication portion through a part of the flow channels, and the second sub-chamber is in communication with the communication portion through another part of the flow channels.

[0038] In the implementation solution, the heat generated by the power device is transferred to the liquid cooling working medium in the first chamber. The liquid cooling working medium absorbs heat and boils to form gaseous cooling working medium. The gaseous cooling working medium flows from the first chamber to the first sub-chamber through the through hole, and then flows from the first sub-chamber to the communication portion through a part of the flow channels. The gaseous cooling working medium releases heat and condenses to form liquid cooling working medium in the first sub-chamber, the flow channels between the first sub-chamber and the communication portion, and the communication portion. The liquid cooling working medium flows to the communication portion under the action of gravity. The second sub-chamber, the communication portion, and the flow channels between the communication portion and the second sub-chamber all contain liquid cooling working medium. The design of the reinforcing portion is beneficial to improving the strength of the chamber wall of the second chamber, improving the structural stability and reliability of the heat dissipation substrate, and improving the structural stability and reliability of the radiator.

[0039] In a possible implementation, the first chamber further comprises a plurality of channels, and the plurality of channels are separated by a plurality of partition plates. In the first direction, each partition plate is fixedly connected with the chamber wall of the first chamber and the partition portion. Each channel is in communication with the through hole. The projection of the power device in the first direction overlaps the projection of the plurality of channels in the first direction.

[0040] In the implementation solution, the plurality of channels all contain liquid cooling working medium. The heat generated by the power device is transferred to the liquid cooling working medium in the plurality of channels. The liquid cooling working medium absorbs heat and boils to form gaseous cooling working medium. The gaseous cooling working medium flows to the second chamber through the through hole. The gaseous cooling working medium releases heat and condenses to form liquid cooling working medium. The working medium pump drives the liquid cooling working medium to flow into the plurality of channels in the first chamber. The first chamber is divided into a plurality of channels by the partition plates, so that the pressure of the liquid working medium is evenly dispersed in each channel. The partition plates can also bear a certain pressure, so that the stability of the entire heat dissipation substrate is better, and the structural stability and reliability of the radiator are improved.

[0041] In a possible implementation, the plurality of partition plates are sequentially and spacedly arranged along a second direction, and the channel extends along a gravity direction, and the second direction is perpendicular to the first direction and the gravity direction.

[0042] In the implementation, the channel extends along the gravity direction, which is beneficial to reduce the flow resistance of the cooling working medium in the liquid state flowing in the channel, reduce the difficulty of driving the liquid level of the cooling working medium to be higher than the power device, reduce the head requirement and service life requirement of the working medium pump, reduce the processing cost of the working medium pump, and reduce the processing cost of the power conversion device.

[0043] In a possible implementation, the plurality of partition plates are sequentially and spacedly arranged along a gravity direction, and the channel extends along a second direction, and the second direction is perpendicular to the first direction and the gravity direction.

[0044] In the implementation, the channel extends along the second direction, which is beneficial to increase the difficulty of the cooling working medium in the liquid state flowing from the channel to the second chamber through the through hole, keep the cooling working medium in the liquid state always higher than the power device, improve the efficiency of heat generated by the power device during operation being transferred to the cooling working medium, and improve the heat dissipation efficiency of the power device.

[0045] In a possible implementation, the plurality of channels include a plurality of first channels and a plurality of second channels, and the plurality of second channels and the plurality of first channels are sequentially arranged along the gravity direction, one end of each first channel is in communication with one end of each second channel, and the other end of each second channel is in communication with the through hole.

[0046] In the implementation, the working medium pump drives the cooling working medium to flow through each first channel and then through each second channel, which plays a guiding role in the flow of the cooling working medium in the first chamber, is beneficial to reduce the difficulty of the liquid level of the cooling working medium in the liquid state in the first chamber being higher than each power device, reduce the head requirement and service life requirement of the working medium pump, reduce the processing cost of the working medium pump, and reduce the processing cost of the power conversion device. Moreover, the structure of the first chamber is various, the design cost is low, and the processing cost of the power conversion device is reduced.

[0047] In a second aspect, the embodiments of the present application also provide a heat dissipation assembly for heat exchange with a power device. The heat dissipation assembly comprises a heat sink and a working medium pump. The heat sink comprises a heat dissipation substrate, a plurality of condensation flat tubes and a communication part. The heat dissipation substrate is in heat exchange with the power device. The heat dissipation substrate comprises a first chamber and a second chamber divided by a partition. In a first direction, the first chamber is located on a side of the second chamber close to the power device, and the first direction is different from a gravity direction. In the gravity direction, a top of the partition is provided with a through hole, and the first chamber is in communication with the second chamber through the through hole. The plurality of condensation flat tubes are located on a side of the heat dissipation substrate away from the power device and are arranged at intervals. The plurality of condensation flat tubes are in communication with each other through the communication part, and the second chamber is in communication with the plurality of condensation flat tubes. The first chamber, the second chamber and the condensation flat tubes are all used for containing cooling working medium for gas-liquid phase conversion. The working medium pump is used for driving the cooling working medium in liquid state to flow to the first chamber.

[0048] In the above implementation scheme, the heat dissipation assembly is applied to a power conversion device. Heat generated by the power device during operation is transferred to the cooling working medium in liquid state in the first chamber. The cooling working medium absorbs heat to boil and form cooling working medium in gaseous state. The cooling working medium in gaseous state flows from the first chamber to the second chamber through the through hole, and then flows to the communication part through the plurality of condensation flat tubes. The cooling working medium in gaseous state releases heat to condense and form cooling working medium in liquid state. The cooling working medium in liquid state is accumulated in the first chamber, the condensation flat tubes and the communication part under the action of gravity. The heat dissipation of the power device is realized through the gas-liquid phase conversion of the cooling working medium. In the embodiments of the present application, the working medium pump can recycle the cooling working medium, so as to ensure that the cooling working medium in liquid state in the first chamber always has sufficient amount. In combination with the partition, the first chamber for evaporation is isolated from other chambers. The working medium pump can drive the cooling working medium in liquid state from the second chamber or the communication part to the first chamber through the working medium pump, so that the liquid level of the cooling working medium in liquid state in the first chamber and the second chamber is controlled by the working medium pump. That is, the parameters of the working medium pump can be set according to needs, so that the liquid level of the cooling working medium in liquid state in the first chamber can meet the product needs. For example, when there are more power devices, the liquid level of the cooling working medium in liquid state in the first chamber can be higher, and the liquid level of the cooling working medium in liquid state in the first chamber can be lower, so that more power devices can be attached to the heat dissipation substrate and cooled by the cooling working medium in the first chamber.

[0049] Compared with the prior art, the radiator integrates the functions of the evaporator and the condenser, which is beneficial to improve the integration of the radiator, reduce the structural complexity of the radiator, improve the structural stability and reliability of the radiator, reduce the volume of the radiator, and facilitate the miniaturization design of the power conversion device. In addition, the design of the gas-liquid two-phase circulation of the cooling working medium and the recycling of the cooling working medium in the application combines gravity and the working medium pump, which is beneficial to reduce the influence of gravity on the design of the radiator, the bottom wall of the second chamber can be higher than the bottom wall of the first chamber, the second chamber can be set without considering the position of the power device, and the bottom wall of the second chamber can be higher than the power device, which is beneficial to reduce the volume of the radiator, improve the space utilization of the power conversion device, and facilitate the miniaturization design of the power conversion device. In addition, it is not only beneficial to reduce the design difficulty of the radiator and reduce the processing cost of the radiator, but also facilitate the arrangement of the power device, reduce the installation difficulty of the power device and the radiator, and reduce the processing cost of the power conversion device.

[0050] In addition, since the working medium pump only needs to overcome the flow resistance of the cooling working medium in liquid state flowing from the second chamber or the communication part to the first chamber through the working medium pump, the pressure head and service life requirements of the working medium pump are low, the processing cost of the working medium pump is low, the cooling cost is reduced, the speed of the gas-liquid two-phase conversion of the cooling working medium is improved, and the heat dissipation efficiency of the power device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the application or the background art, the drawings needed to be used in the embodiments of the application or the background art will be described below.

[0052] FIG. 1 is a structural block diagram of a power conversion device cooperating with a photovoltaic module and a power grid according to an embodiment of the application;

[0053] FIG. 2 is a perspective structural schematic view of the power conversion device shown in FIG. 1;

[0054] FIG. 3 is a structural schematic view of the power conversion device shown in FIG. 2 from another angle;

[0055] FIG. 4 is a structural schematic view of the power conversion device (omitting the cooling working medium and the heat exchanger) shown in FIG. 3 along the A-A line;

[0056] FIG. 5 is a structural schematic view of the radiator (omitting the first fan, the heat exchanger and the second fan) of the power conversion device shown in FIG. 3 cooperating with the power device;

[0057] FIG. 6 is a structural schematic view of the radiator shown in FIG. 5 along the B-B line;

[0058] FIG. 7 is a structural schematic view of the radiator shown in FIG. 5 along the C-C line;

[0059] Fig. 8 is a structural schematic diagram of the power conversion device shown in Fig. 3 in another embodiment;

[0060] Fig. 9 is a structural schematic diagram of the power conversion device shown in Fig. 3 in another embodiment;

[0061] Fig. 10 is a structural schematic diagram of the power conversion device shown in Fig. 2 in another embodiment;

[0062] Fig. 11 is a structural schematic diagram of the power conversion device shown in Fig. 3 along the line D-D;

[0063] Fig. 12 is a structural schematic diagram of another power conversion device provided by the embodiment of the present application;

[0064] Fig. 13 is a structural schematic diagram of the heat dissipation assembly (omitting the first fan, the heat exchanger and the second fan) of the power conversion device shown in Fig. 12 cooperating with the power device;

[0065] Fig. 14 is a structural schematic diagram of another power conversion device provided by the embodiment of the present application;

[0066] Fig. 15 is a partial structural schematic diagram of the power conversion device shown in Fig. 14 along the line E-E;

[0067] Fig. 16 is a structural schematic diagram of the power conversion device shown in Fig. 15 along the line F-F;

[0068] Fig. 17 is a structural schematic diagram of another power conversion device provided by the embodiment of the present application;

[0069] Fig. 18 is a structural schematic diagram of the heat dissipation assembly (omitting the first fan, the heat exchanger and the second fan) of the power conversion device shown in Fig. 17 cooperating with the power device;

[0070] Fig. 19 is a structural schematic diagram of the heat sink shown in Fig. 18 along the line G-G;

[0071] Fig. 20 is a structural schematic diagram of another power conversion device provided by the embodiment of the present application;

[0072] Fig. 21 is a structural schematic diagram of the heat dissipation assembly (omitting the first fan, the heat exchanger and the second fan) of the power conversion device shown in Fig. 20 cooperating with the power device. DETAILED DESCRIPTION

[0073] The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0074] Please refer to Fig. 1, which is a structural block diagram of a power conversion device 100 cooperating with a photovoltaic assembly 200 and a power grid 300 provided by the embodiment of the present application.

[0075] The power conversion device 100 is exemplarily a photovoltaic inverter. In other embodiments, the power conversion device 100 can also be a rectifier, a transformer, a current transformer, or other inverters, etc. electronic devices for power conversion. The power conversion device 100 is used to convert the direct current output by the photovoltaic module 200 into alternating current and supply the power grid 300. In other embodiments, the power conversion device 100 can also be used to convert the direct current output by the photovoltaic module 200 into alternating current and supply a load device. The load device can be an electronic device using alternating current, including but not limited to a motor, a fan, or an air conditioner, etc. In other embodiments, the power conversion device 100 can also be applied to an electric drive controller. For example, the power conversion device 100 can convert the direct current output by the battery into alternating current to supply the motor.

[0076] As the power of the power conversion device becomes larger and larger, the heat generated by the circuit board assembly inside the power conversion device cabinet also becomes larger and larger, thereby causing the temperature inside the cabinet to rise, which is very unfavorable to the heat generating components arranged inside the cabinet. Especially for some power devices with high heat dissipation density, the failure risk of the power device is significantly increased under the influence of continuous high temperature.

[0077] In the prior art, the heat generated by the power device of the power conversion device during operation is transferred to the cooling working medium in the liquid state in the evaporator. The cooling working medium in the evaporator absorbs heat and boils, and the gaseous cooling working medium is transferred to the condenser through the pipeline. The gaseous cooling working medium is condensed in the condenser to form liquid cooling working medium, and the liquid cooling working medium flows back to the evaporator under the action of gravity through the pipeline, realizing the recycling of the cooling working medium. The air flowing into the power conversion device flows through the condenser and then flows out of the power conversion device, thereby cooling the power device. Through the gas-liquid phase conversion of the cooling working medium and the recycling of the cooling working medium, the power device can be stably cooled. However, in order to ensure that the gaseous working medium that has absorbed the heat generated by the power device during operation can flow into the condenser, and at the same time ensure that the liquid cooling working medium in the condenser can flow back to the evaporator under the action of gravity, the condenser needs to be arranged above the evaporator and the power device. The condenser, the evaporator, and the pipeline therebetween occupy a large space, resulting in low space utilization of the power conversion device, which is not conducive to the miniaturization design of the power conversion device.

[0078] To solve the above problems, the embodiment of the present application provides a heat dissipation assembly to replace the evaporator and the condenser to cool the power device. Not only does it simplify the structure for cooling, but also by changing the way of recycling the cooling working medium, it reduces the influence of gravity on the structure of the heat dissipation assembly, thereby reducing the volume of the heat dissipation assembly and improving the space utilization of the power conversion device, facilitating the miniaturization design of the power conversion device.

[0079] For the convenience of description, the three perpendicular directions are defined as a first direction (i.e. the X-axis direction shown in the figures), a second direction (i.e. the Z-axis direction shown in the figures) and a third direction (i.e. the Y-axis direction shown in the figures) in the present application, and the first direction, the second direction and the third direction are perpendicular to each other. The first direction and the second direction are different from the direction of gravity. In the present embodiment, the first direction is perpendicular to the direction of gravity. The first direction is parallel to the horizontal plane. The second direction is perpendicular to the first direction and the direction of gravity. The third direction is parallel to the direction of gravity, and the third direction is perpendicular to the horizontal plane. In some other embodiments, the third direction (i.e. the Y-axis direction shown in the figures) can be inclined to the direction of gravity. The first direction (i.e. the X-axis direction shown in the figures) can also be not perpendicular to the direction of gravity. The second direction (i.e. the Z-axis direction shown in the figures) can also be not perpendicular to the direction of gravity. The horizontal plane refers to a plane perpendicular to the direction of gravity, i.e. the horizontal plane is perpendicular to the direction of gravity.

[0080] Please refer to FIG. 2, FIG. 3 and FIG. 4, and combine with FIG. 1. FIG. 2 is a perspective structural schematic diagram of the power conversion device 100 shown in FIG. 1. FIG. 3 is a structural schematic diagram of the power conversion device 100 shown in FIG. 2 from another angle. FIG. 4 is a structural schematic diagram of the power conversion device 100 (omitting the cooling working medium 41a and the heat exchanger 60) shown in FIG. 3 along the line A-A. It should be understood that the above schematic diagrams are all position relationship diagrams of the power conversion device 100 in the working state when it is hung on a wall or placed on the ground, i.e. at this time the third direction (the Y-axis direction shown in the figures) in the figures is parallel to the direction of gravity. When installing or transporting, the power conversion device 100 can be in other placement states, and at this time the direction of gravity can be not the direction of gravity referred to in the present application.

[0081] As shown in FIG. 2, FIG. 3 and FIG. 4, the power conversion device 100 comprises a shell 10, a power conversion circuit 20 and a heat dissipation assembly 30. The power conversion circuit 20 and the heat dissipation assembly 30 are both accommodated in the shell 10. The direct current output by the photovoltaic assembly 200 is delivered to the power conversion circuit 20. The power conversion circuit 20 is used for converting the direct current output by the photovoltaic assembly into alternating current. The alternating current output by the power conversion circuit 20 is delivered to the power grid 300 for supplying the power grid 300. The heat dissipation assembly 30 is used for dissipating heat for the power conversion circuit 20.

[0082] Specifically, the housing 10 comprises a first cavity 11 and a second cavity 12. In the X-axis direction (i.e. the first direction), the first cavity 11 and the second cavity 12 are spaced apart by a partition cavity wall 13a. Specifically, the housing 10 comprises the partition cavity wall 13a, a first cavity wall 13b and a second cavity wall 13c, the first cavity wall 13b and the partition cavity wall 13a jointly form the first cavity 11, and the second cavity wall 13c and the partition cavity wall 13a jointly form the second cavity 12. The first cavity 11 is a closed cavity for accommodating the power device, and the second cavity 12 is an open and ventilated heat dissipation cavity. The housing 10 is provided with an air inlet hole 14 and an air outlet hole 15. The air inlet hole 14 and the air outlet hole 15 are both in communication with the second cavity 12. External airflow can flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15, so as to dissipate heat from the device accommodated in the second cavity 12.

[0083] As shown in FIG. 1 and FIG. 2, the power conversion circuit 20 comprises a power device 21, and further comprises a circuit board 22, a magnetic device 23 and other electronic devices 24. In some embodiments, the power device 21, the circuit board 22 and the other electronic devices 24 are all accommodated in the first cavity 11, and the magnetic device 23 is accommodated in the second cavity 12. The power device 21 and the other electronic devices 24 are both mounted on the circuit board 22. Specifically, the circuit board 22 is mounted on the side of the power device 21 away from the second cavity 12, and the electronic devices 24 are mounted on the side of the circuit board 22 away from the power device 21. In other embodiments, the other electronic devices 24 can also be mounted on the side of the circuit board 22 facing the power device 21. The magnetic device 23 is electrically connected with the circuit board 22. The power device 21 is a packaged module or device for converting direct current output by the photovoltaic module 200 into alternating current. Exemplarily, the power device 21 can be, but is not limited to, an IGBT (Insulated Gate Bipolar Transistor) chip, an FRD (Fast Recovery Diode) chip or a Mosfet (Metal oxide places semiconductor field-effect transistor) chip, etc. The magnetic device 23 cooperates with the other electronic devices 24 to filter the current transmitted in the power conversion circuit 20. Exemplarily, the magnetic device 23 is an inductor, and the other electronic devices 24 are capacitors. In other embodiments, the other electronic devices 24 can also be fuses or other switching devices.

[0084] As shown in FIG. 2, FIG. 3 and FIG. 4, the heat dissipation assembly 30 comprises a heat sink 41 and a working medium pump 42, and further comprises a first fan 50, a heat exchanger 60 and a second fan 70. In some embodiments, the heat sink 41, the working medium pump 42, the first fan 50 and the heat exchanger 60 are all accommodated in the second cavity 12, and the second fan 70 is accommodated in the first cavity 11. The heat sink 41 cooperates with the working medium pump 42 to exchange heat with the power device 21. The heat exchanger 60 is used to exchange heat with the first cavity 11. The working medium pump 42 is mounted on the heat sink 41. The heat sink 41, the working medium pump 42, the heat exchanger 60 and the magnetic device 23 are located on one side of the first fan 50.

[0085] The heat sink 41 comprises a heat dissipation substrate 411, a plurality of condensing flat tubes 412 and a communication part 413. The plurality of condensing flat tubes 412 are located between the heat dissipation substrate 411 and the communication part 413. The heat dissipation substrate 411 is used to exchange heat with the power device 21. Specifically, the housing 10 is provided with a connecting hole 16 penetrating through the isolation cavity wall 13a along the X-axis direction, the connecting hole 16 communicates with the first cavity 11 and the second cavity 12, the power device 21 can be fitted in the connecting hole 16, the heat dissipation substrate 411 contacts the power device 21 through the connecting hole 16, and covers the connecting hole 16 to close the first cavity 11. In other embodiments, the heat dissipation substrate 411 can also contact and be fixedly connected with the power device 21, so as to improve the structural stability between the heat dissipation substrate 411 and the power device 21, and improve the stability of heat conduction between the power device 21 and the heat dissipation substrate 411.

[0086] The heat dissipation substrate 411 comprises a first chamber 415 and a second chamber 416 divided by a partition 414. In the X-axis direction, the first chamber 415 is located on the side of the second chamber 416 close to the power device 21. In the Y-axis direction (i.e. the direction of gravity), the top of the partition 414 is provided with a through hole 4141, and the first chamber 415 communicates with the second chamber 416 through the through hole 4141. Specifically, the through hole 4141 penetrates through the partition 414 along the X-axis direction and communicates with the first chamber 415 and the second chamber 416. The plurality of condensing flat tubes 412 are located on the side of the heat dissipation substrate 411 away from the power device 21 and are arranged at intervals. Specifically, the plurality of condensing flat tubes 412 are located on the side of the heat dissipation substrate 411 away from the power device 21 and are arranged at intervals. The plurality of condensing flat tubes 412 communicate with each other through the communication part 413, and the second chamber 416 communicates with the plurality of condensing flat tubes 412. The condensing flat tubes 412 are located between the air inlet hole 14 and the air outlet hole 15.

[0087] The first chamber 415, the second chamber 416 and the condensing flat tubes 412 are used to accommodate the cooling medium 41a for gas-liquid two-phase conversion. The communication part 413 can also be used to accommodate the cooling medium 41a for gas-liquid two-phase conversion. The working medium pump 42 is used to drive the cooling medium 41a in liquid state to flow to the first chamber 415. The working medium pump 42 can drive the cooling medium 41a in liquid state to flow to the first chamber 415 from the second chamber 416 or the communication part 413 through the working medium pump 42. The cooling medium 41a can be a cooling fluid including but not limited to water, ethylene glycol or propylene glycol. In the embodiment of the present application, the condensing flat tubes 412 can be flat hollow plate structures for liquid medium flow. It should be understood that the condensing flat tubes 412 can also be other structural designs, which are not limited in the present application.

[0088] The heat generated by the power device 21 during operation is transferred to the heat sink 41. The external airflow can flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15 through the heat sink 41, thereby achieving heat dissipation of the power device 21. The heat generated by the power device 21 during operation is transferred to the cooling medium 41a in liquid state in the first chamber 415. The cooling medium 41a absorbs heat to boil and form the cooling medium 41a in gaseous state. The cooling medium 41a in gaseous state flows to the second chamber 416 from the first chamber 415 through the through hole 4141, and then flows to the communication part 413 through the plurality of condensing flat tubes 412. The cooling medium 41a in gaseous state releases heat to condense and form the cooling medium 41a in liquid state. The cooling medium 41a in liquid state accumulates in the first chamber 415, the condensing flat tubes 412 and the communication part 413 under the action of gravity. The first fan 50 can drive the external airflow to flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15 through the heat sink 41. The heat transferred from the power device 21 to the cooling medium 41a can be transferred to the external environment through the airflow flowing through the heat sink 41. Thus, the heat dissipation of the power device 21 is achieved through the gas-liquid two-phase conversion of the cooling medium 41a.

[0089] The working medium pump 42 can drive the cooling medium 41a in liquid state to flow to the first chamber 415 from the second chamber 416 or the communication part 413 through the working medium pump 42, thereby achieving recycling of the cooling medium 41a and ensuring that the cooling medium 41a in liquid state in the first chamber 415 always has sufficient amount to stably dissipate heat of the power device 21. The first fan 50 can drive the external airflow to flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15 through the magnetic device 23, thereby achieving heat dissipation of the magnetic device 23. The heat generated by the electronic device 24 during operation can be transferred to the heat exchanger 60 through the second fan 70. The first fan 50 can drive the external airflow to flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15 through the heat exchanger 60, thereby achieving heat dissipation of the electronic device 24.

[0090] It can be seen that the power conversion device 100 provided by the application replaces the existing evaporator and condenser for dissipating heat from the power device 21 by the heat sink 41 and the working medium pump 42, integrates the functions of the evaporator and the condenser by the heat sink 41, avoids setting a complex pipeline, simplifies the structure of the heat sink 41, is conducive to reducing the volume of the heat sink 41, and is conducive to reducing the space occupancy of the heat sink 41; moreover, the working medium pump 42 applies a driving force to the liquid cooling medium 41a, so that the liquid cooling medium 41a formed by heat release and condensation can supplement the liquid cooling medium 41a in the first chamber 415, realizes the recycling of the cooling medium 41a, and then realizes the stable heat dissipation of the power device 21, reduces the influence of gravity on the design of the heat sink 41, is conducive to reducing the volume of the heat sink 41, is conducive to improving the space utilization of the power conversion device 100, and facilitates the miniaturization design of the power conversion device 100.

[0091] Based on the above-mentioned concept of recycling the cooling medium 41a by the working medium pump 42, the working medium pump 42 can only drive the liquid cooling medium 41a formed by heat release and condensation to flow to the first chamber 415, and the installation mode between the working medium pump 42 and the heat sink 41 can be various, for example, the working medium pump 42 can be located outside the heat sink 41, wherein the working medium pump 42 can be above, beside, below, above the side or other positions of the heat sink 41; the working medium pump 42 can also be located inside the heat sink 41, and the like, which is not limited by the application. The following is exemplarily described in multiple embodiments.

[0092] Please refer to FIG. 5, FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10 and FIG. 11, and combine FIG. 3 and FIG. 4, FIG. 5 is a structural schematic diagram of the heat dissipation assembly 30 (omitting the first fan 50, the heat exchanger 60 and the second fan 70) of the power conversion device 100 shown in FIG. 3 cooperating with the power device 21. FIG. 6 is a structural schematic diagram of the heat sink 41 shown in FIG. 5 along the B-B line. FIG. 7 is a structural schematic diagram of the heat sink 41 shown in FIG. 5 along the C-C line. FIG. 8 is a structural schematic diagram of the power conversion device 100 shown in FIG. 3 in another embodiment. FIG. 9 is a structural schematic diagram of the power conversion device 100 shown in FIG. 3 in another embodiment. FIG. 10 is a structural schematic diagram of the power conversion device 100 shown in FIG. 2 in another embodiment. FIG. 11 is a structural schematic diagram of the power conversion device 100 shown in FIG. 3 along the D-D line. It should be noted that the dashed box in FIG. 7 schematically indicates the position of the power device 21.

[0093] As shown in FIG. 3 and FIG. 4, in the embodiment shown in FIG. 3 and FIG. 4, the communication part 413 includes a flow cavity 4130 for accommodating the cooling medium 41a used for gas-liquid phase conversion. The communication part 413 is located on the side of the plurality of condensing flat tubes 412 away from the power device 21, and is fixedly connected with the plurality of condensing flat tubes 412. The flow cavity 4130 is in communication with the plurality of condensing flat tubes 412. The plurality of condensing flat tubes 412 are in communication with each other through the flow cavity 4130. The communication part 413 is located on the side of the plurality of condensing flat tubes 412 away from the heat dissipation base plate 411. The design that the communication part 413 is fixedly connected with the plurality of condensing flat tubes 412 is conducive to improving the stability of the interval arrangement of the plurality of condensing flat tubes 412, and is conducive to improving the structural stability and reliability of the heat dissipation device 41.

[0094] Further, the plurality of condensing flat tubes 412 are sequentially and interval arranged along the Z-axis direction (i.e. the second direction) to form the ventilation holes 4120. The ventilation holes 4120 extend along the Y-axis direction. For example, the number of the condensing flat tubes 412 is 3. The 3 condensing flat tubes 412 are sequentially and interval arranged along the Z-axis direction to form 3 ventilation holes 4120. In some other embodiments, the number of the condensing flat tubes 412 can also be 2, 4 or more. The external airflow can flow into the second cavity 12 from the air inlet hole 14, then flow through the plurality of condensing flat tubes 412 from the air outlet hole 15 to flow out of the second cavity 12, so as to transfer the heat generated by the power device 21 during operation to the external environment. The design that the plurality of condensing flat tubes 412 are sequentially and interval arranged along the second direction to form the ventilation holes 4120 is conducive to improving the contact area of the plurality of condensing flat tubes 412 with the external airflow, and is conducive to improving the heat dissipation efficiency of the power device 21. Moreover, the structure is simple and stable, and is convenient for design, which is conducive to reducing the processing cost of the heat dissipation device 41.

[0095] In this embodiment, the condensing flat tubes 412 are located between the air inlet hole 14 and the air outlet hole 15 in the direction of gravity (i.e. the Y-axis direction). The design of locating the plurality of condensing flat tubes 412 between the air inlet hole 14 and the air outlet hole 15 in the direction of gravity facilitates reducing the flow resistance of the external airflow flowing into the second cavity 12 from the air inlet hole 14 through the ventilation holes 4120 and passing through the plurality of condensing flat tubes 412, and facilitates improving the heat dissipation efficiency of the plurality of condensing flat tubes 412 and the power device 21. Specifically, the air inlet hole 14 penetrates the second cavity wall 13c along the Y-axis direction. The air outlet hole 15 penetrates the second cavity wall 13c along the X-axis direction. In the direction of gravity (i.e. the Y-axis direction), the air inlet hole 14 is located below the condensing flat tubes 412, and the air outlet hole 15 is located above the condensing flat tubes 412. In the X-axis direction, the air outlet hole 15 is located on the side of the second cavity 12 away from the isolation cavity wall 13a. Thus, the external airflow flows into the second cavity 12 from the bottom of the power conversion device 100, and then flows out from the back of the power conversion device 100 after passing through the plurality of condensing flat tubes 412, avoiding the external airflow flowing out from the top of the power conversion device 100, avoiding foreign matter (such as fallen leaves or dust, etc.) blocking the air outlet hole 15, ensuring that the external airflow can flow smoothly, and facilitating improving the heat dissipation effect of the condensing flat tubes 412.

[0096] In some embodiments, the projection of the plurality of condensing flat tubes 412 in the direction of gravity and the projection of the air inlet hole 14 in the direction of gravity overlap, so as to increase the heat dissipation area of the condensing flat tubes 412 and the external airflow, and further improve the heat dissipation efficiency. Of course, the projection of the air inlet hole 14 in the direction of gravity can also cover more parts of the heat sink 41 to further increase the heat dissipation area.

[0097] As shown in FIG. 5 and FIG. 6, each condensing flat tube 412 can include a plurality of flow channels 4121 extending along the first direction, adjacent flow channels are separated by baffles 4122, and the plurality of flow channels 4121 are in communication with the second cavity 416 and the communication part 413. Specifically, the plurality of flow channels 4121 are in communication between the second cavity 416 and the flow-through cavity 4130, and the plurality of flow channels 4121 are arranged in sequence along the Y-axis direction. Dividing the condensing flat tube 412 into a plurality of flow channels 4121 can uniformly distribute the pressure generated by the gaseous working medium in each flow channel 4121, and the baffles 4122 can also withstand a certain pressure, avoiding the problem of bulging, making the stability of the entire condensing flat tube 412 better, and facilitating improving the structural stability and reliability of the heat sink 41.

[0098] In some embodiments, the working fluid pump 42 is located outside the heat sink 41, and the working fluid pump 42 includes an inlet 421 and an outlet 422. The heat dissipation assembly 30 (i.e., the power conversion device 100) further includes an input pipe 43 and an output pipe 44. The inlet 421 of the working fluid pump 42 is in communication with the second chamber 416 or the communication portion 413 through the input pipe 43, and the outlet 422 of the working fluid pump 42 is in communication with the first chamber 415 through the output pipe 44. The working fluid pump 42 is located outside the heat sink 41, the inlet 421 of the working fluid pump 42 is in communication with the second chamber 416 or the communication portion 413 through the input pipe 43, and the outlet 422 of the working fluid pump 42 is in communication with the first chamber 415 through the output pipe 44. This design facilitates the maintenance and replacement of the working fluid pump 42, reduces the maintenance cost of the heat sink 41, and reduces the maintenance cost of the power conversion device 100.

[0099] Further, the heat sink 41 is provided with an input pipe mounting hole 417 and an output pipe mounting hole 418. In the gravity direction, the input pipe mounting hole 417 is located below the second chamber 416 or the communication portion 413, and the output pipe mounting hole 418 is located below the first chamber 415. The working fluid pump 42 is located below the heat sink 41. The input pipe 43 is inserted into the input pipe mounting hole 417, and the output pipe 44 is inserted into the output pipe mounting hole 418.

[0100] As shown in FIGS. 5, 6 and 7, in the specific embodiments shown in FIGS. 5, 6 and 7, in the gravity direction, the input pipe mounting hole 417 is located below the second chamber 416, and the output pipe mounting hole 418 is located below the first chamber 415. The input pipe 43 is inserted into the input pipe mounting hole 417, the inlet 421 of the working fluid pump 42 is in communication with the second chamber 416 through the input pipe 43, and the output pipe 44 is inserted into the output pipe mounting hole 418. The outlet 422 of the working fluid pump 42 is in communication with the first chamber 415 through the output pipe 44.

[0101] Specifically, the heat dissipation base plate 411 includes a first connecting wall 4111, a second connecting wall 4112, a third connecting wall 4113, a fourth connecting wall 4114, and two fifth connecting walls 4115. The first connecting wall 4111, the second connecting wall 4112, the third connecting wall 4113, the fourth connecting wall 4114, and the two fifth connecting walls 4115 enclose an inner cavity of the heat dissipation base plate 411. Among them, in the X-axis direction, the first connecting wall 4111 and the second connecting wall 4112 are oppositely and spacedly arranged. In the Y-axis direction (i.e. the direction of gravity), the third connecting wall 4113 and the fourth connecting wall 4114 are oppositely and spacedly arranged and located above the fourth connecting wall 4114. In the Z-axis direction, the two fifth connecting walls 4115 are oppositely and spacedly arranged. A partition is arranged between the fourth connecting wall 4114 and the third connecting wall 4113 to divide the inner cavity of the heat dissipation base plate 411 into a first chamber 415 and a second chamber 416. An input pipe body mounting hole 417 penetrates the fourth connecting wall 4114 in the Y-axis direction and communicates with the second chamber 416. An output pipe body mounting hole 418 penetrates the fourth connecting wall 4114 in the Y-axis direction and communicates with the second chamber 416. The axis of the input pipe body mounting hole 417 and the axis of the output pipe body mounting hole 418 can be parallel to the Y-axis direction or can be arranged obliquely relative to the Y-axis direction. The input pipe body 43 communicates with the second chamber 416 and the inlet 421. The output pipe body 44 communicates with the first chamber 415 and the outlet 422.

[0102] The design that the inlet 421 of the working medium pump 42 communicates with the second chamber 416 through the input pipe body 43 is beneficial to reduce the structural complexity and length of the input pipe body 43, reduce the material cost of the heat sink 41, reduce the structural complexity of the heat sink 41, improve the structural reliability of the heat sink 41, improve the efficiency of the cooling working medium 41a flowing from the second chamber 416 to the first chamber 415 through the working medium pump 42, and improve the heat dissipation efficiency of the power device 21.

[0103] In some other embodiments, the input pipe body mounting hole 417 can also be located below the flow passage cavity 4130 (i.e., the communication part 413) in the direction of gravity, the input pipe body 43 is mounted in the input pipe body mounting hole 417, and the inlet 421 of the working medium pump 42 communicates with the flow passage cavity 4130 (i.e., the communication part 413) through the input pipe body 43. For example, the communication part 413 can include the first fitting wall 4131, the second fitting wall 4132, the third fitting wall 4133, the fourth fitting wall 4134, and two fifth fitting walls 4135 that enclose the flow passage cavity 4130. Among them, in the X-axis direction, the first fitting wall 4131 and the second fitting wall 4132 are oppositely and spacedly arranged. In the Y-axis direction, the third fitting wall 4133 and the fourth fitting wall 4134 are oppositely and spacedly arranged and located above the fourth fitting wall 4134. In the Z-axis direction, the two fifth fitting walls 4135 are oppositely and spacedly arranged. The output pipe body mounting hole 418 penetrates the fourth fitting wall 4134 along the Y-axis direction and communicates with the flow passage cavity 4130. The axis of the input pipe body mounting hole 417 and the axis of the output pipe body mounting hole 418 can be parallel to the Y-axis direction or can be arranged obliquely relative to the Y-axis direction. The input pipe body 43 communicates with the flow passage cavity 4130 (i.e., the communication part 413) and the inlet 421. The connection mode of the working medium pump 42 and the heat sink 41 through the input pipe body 43 is various, which can be designed according to the needs, and is beneficial to reduce the installation cost of the heat sink 41 and the working medium pump 42.

[0104] The liquid cooling working medium 41a formed by heat release condensation is accumulated at the bottom of the first chamber 415, the bottom of the second chamber 416, the bottom of the condensation flat tube 412, and the bottom of the communication part 413 under the action of gravity. The design that the working medium pump 42 is located below the heat sink 41 is beneficial to reduce the structural complexity and length of the input pipe body 43 that communicates with the second chamber 416 (or the communication part 413) and the inlet 421 of the working medium pump 42, reduce the structural complexity and length of the output pipe body 44 that communicates with the first chamber 415 and the outlet 422 of the working medium pump 42, reduce the material cost of the heat sink 41, reduce the structural complexity of the heat sink 41, and improve the structural reliability of the heat sink 41.

[0105] In addition, the power conversion device 100 can be installed on various bearing surfaces, and the design that the inlet 421 of the working medium pump 42 communicates with the second chamber 416 or the communication part 413 through the input pipe body 43 can adapt to various installation scenes of the power conversion device 100. For specific details, refer to FIG. 5, FIG. 8, FIG. 9, and FIG. 10, which exemplarily list the installation scenes of the power conversion device 100 installed on various bearing surfaces.

[0106] In the embodiment shown in Fig. 5, the working fluid pump 42 is in communication with the second chamber 416 through the input pipe 43. When the power conversion device 100 is installed on a bearing surface (for example, hung on a wall surface perpendicular to the horizontal surface), the first direction (i.e., the X-axis direction) is perpendicular to the direction of gravity, and under the action of gravity, the cooling working fluid 41a in liquid state formed by heat release and condensation can accumulate at the bottom of the second chamber 416 and have a larger amount at the bottom of the second chamber 416. In this case, the working fluid pump 42 can stably drive the cooling working fluid 41a in liquid state from the second chamber 416 to the first chamber 415 through the working fluid pump 42 via the input pipe 43 in communication with the second chamber 416, which is conducive to improving the reliability and stability of heat dissipation of the power device 21. Moreover, in this case, under the action of gravity, the cooling working fluid 41a in liquid state formed by heat release and condensation can also accumulate at the bottom of the communication part 413 (i.e., the bottom of the flow-through cavity 4130), and have a larger amount at the bottom of the communication part 413 (i.e., the bottom of the flow-through cavity 4130). At this time, if the working fluid pump 42 is in communication with the communication part 413 through the input pipe 43, the working fluid pump 42 can also stably drive the cooling working fluid 41a in liquid state from the communication part 413 to the first chamber 415 through the working fluid pump 42 via the input pipe 43 in communication with the communication part 413, which is also conducive to improving the reliability and stability of heat dissipation of the power device 21.

[0107] In the embodiment shown in Fig. 8, the working fluid pump 42 is in communication with the second chamber 416 through the input pipe 43. When the power conversion device 100 is installed on a bearing surface (for example, hung on a wall surface inclined to the horizontal surface), the second chamber 416 is below the communication part 413 in the direction of gravity, and under the action of gravity, the cooling working fluid 41a in liquid state formed by heat release and condensation can accumulate at the bottom of the second chamber 416 and have a larger amount at the bottom of the second chamber 416. In this case, the working fluid pump 42 can stably drive the cooling working fluid 41a in liquid state from the second chamber 416 to the first chamber 415 through the working fluid pump 42 via the input pipe 43 in communication with the second chamber 416, which is conducive to improving the reliability and stability of heat dissipation of the power device 21.

[0108] In the embodiment shown in FIG. 9, the working fluid pump 42 is in communication with the second chamber 416 through the input pipe 43. When the power conversion device 100 is installed on a bearing surface (for example, hung on a wall surface inclined to the horizontal plane), the second chamber 416 is located above the communication portion 413 in the direction of gravity, the first direction is inclined to the horizontal plane, and the angle θ between the first direction and the horizontal plane is less than 30°. Under the action of gravity, the cooling working fluid 41a in liquid state formed by heat release and condensation can accumulate at the bottom of the second chamber 416 and exist in a larger amount at the bottom of the second chamber 416. In this case, the working fluid pump 42 can stably drive the cooling working fluid 41a in liquid state from the second chamber 416 to the first chamber 415 through the working fluid pump 42 via the input pipe 43 in communication with the second chamber 416, which is conducive to improving the reliability and stability of heat dissipation of the power device 21.

[0109] In the embodiment shown in FIG. 10, the working fluid pump 42 is in communication with the communication portion 413 through the input pipe 43. When the power conversion device 100 is installed on a bearing surface (for example, hung on a wall surface inclined to the horizontal plane), the second chamber 416 is located above the communication portion 413 in the direction of gravity. Under the action of gravity, the cooling working fluid 41a in liquid state formed by heat release and condensation accumulates at the bottom of the communication portion 413 and exists in a larger amount at the bottom of the communication portion 413. The first direction is arranged to be inclined to the horizontal plane. For example, the angle θ between the first direction and the horizontal plane is greater than 30°, and in some other embodiments, the angle θ between the first direction and the horizontal plane can also be less than or equal to 30°. In this case, the working fluid pump 42 can stably drive the cooling working fluid 41a in liquid state from the communication portion 413 to the first chamber 415 through the working fluid pump 42 via the input pipe 43 in communication with the communication portion 413, which is conducive to improving the reliability and stability of heat dissipation of the power device 21.

[0110] In the embodiments shown in FIG. 3 and FIG. 4, in the direction of gravity, the liquid level of the cooling working medium 41a in the liquid state in the first chamber 415 is higher than the power device 21. The design that the liquid level of the cooling working medium 41a in the liquid state in the first chamber 415 is higher than the power device 21 is beneficial to improve the efficiency of transferring the heat generated by the power device 21 when working to the cooling working medium 41a in the liquid state in the first chamber 415, and is beneficial to improve the heat dissipation efficiency of the power device 21. For example, the number of power devices 21 is multiple, the number of connecting holes 16 is multiple, the multiple connecting holes 16 correspond to the multiple power devices 21 one by one, the heat dissipation substrate 411 contacts each power device 21 through the corresponding connecting hole 16 and covers the corresponding connecting hole 16 to close the first cavity 11. Among them, the multiple power devices 21 can include two first power devices 21a and two second power devices 21b, and the two first power devices 21a are sequentially and spaced apart in the Y-axis direction. In the Z-axis direction, the two second power devices 21b are located on one side of the two first power devices 21a. In the Y-axis direction, the two second power devices 21b are sequentially and spaced apart. In the direction of gravity, the liquid level of the cooling working medium 41a in the liquid state in the first chamber 415 is higher than each power device 21.

[0111] Further, in the direction of gravity, the liquid level of the cooling working medium in the liquid state in the first chamber is higher than the cooling working medium in the liquid state in the second chamber. In this way, the working medium pump can drive the liquid working medium to flow more to the first chamber, so that the liquid working medium in the first chamber is higher, so that more power devices can be covered, so that more power devices are in contact with the heat dissipation substrate and are cooled through the heat sink, thereby reducing the volume of the power converter and improving the heat dissipation efficiency.

[0112] In the embodiments shown in FIG. 3 and FIG. 4, the projection of the through hole 4141 in the first direction is located above the projection of the power device 21 in the first direction. In the direction of gravity, the projection of the through hole 4141 in the first direction is located above the projection of the power device 21 in the first direction. In the process of driving the liquid level of the cooling working medium 41a in the liquid state in the first chamber 415 to be higher than the power device 21, the cooling working medium 41a in the liquid state in the first chamber 415 is prevented from flowing from the through hole 4141 to the second chamber 416, which is beneficial to reduce the difficulty of driving the liquid level of the cooling working medium 41a in the liquid state in the first chamber 415 to be higher than the power device 21, and is beneficial to improve the heat dissipation efficiency of the power device 21.

[0113] In some embodiments, the liquid level of the cooling working medium 41a in the second chamber 416, the liquid level of the cooling working medium 41a in the condensing flat tubes 412, and the liquid level of the cooling working medium 41a in the communication portion 413 are all lower than the power device 21. In this way, more gaseous cooling working medium 41a can be accommodated in the second chamber 416, the condensing flat tubes 412, and the communication portion 413, which is conducive to increasing the rate of the gaseous cooling working medium 41a flowing from the through hole 4141 into the second chamber 416, and is conducive to improving the heat dissipation efficiency of the power device 21.

[0114] As shown in FIG. 3, the air inlet side of the first fan 50 faces the air inlet hole 14. In the Y-axis direction, the first fan 50 can be located on the side of the heat sink 41 facing or away from the air inlet hole 14. Specifically, in the Y-axis direction, the first fan 50 is located on the side of the condensing flat tubes 412 facing the air inlet hole 14. The first fan 50 can drive the flow of air to form a heat dissipation wind. The first fan 50 can drive the heat dissipation wind to flow into the second chamber 12 from the air inlet hole 14, and then flow out of the second chamber 12 from the air outlet hole 15 through the heat sink 41.

[0115] In some embodiments, the projection of the first fan 50 in the Y-axis direction overlaps the projection of the air inlet hole 14 in the Y-axis direction. Such a design is conducive to reducing the flow resistance of the heat dissipation wind flowing through the plurality of condensing flat tubes 412, increasing the air volume of the heat dissipation wind flowing through the plurality of condensing flat tubes 412, improving the heat dissipation efficiency of the heat dissipation wind on the plurality of condensing flat tubes 412, and improving the heat dissipation efficiency of the power device 21.

[0116] In the embodiments shown in FIG. 3 and FIG. 4, the heat generated by the power device 21 during operation is transferred to the heat sink 41, and external air flow can flow into the second cavity 12 from the air inlet 14, and then flow out of the second cavity 12 from the air outlet 15 through the heat sink 41, thereby achieving heat dissipation of the power device 21. Among them, the heat generated by the power device 21 during operation is transferred to the cooling working medium 41a in the liquid state in the first chamber 415, and the cooling working medium 41a absorbs heat and boils to form the cooling working medium 41a in the gaseous state, and the cooling working medium 41a in the gaseous state flows from the first chamber 415 to the second chamber 416 through the through hole 4141, and then flows to the communication part 413 through the plurality of condensation flat tubes 412. The cooling working medium 41a in the gaseous state releases heat and condenses to form the cooling working medium 41a in the liquid state, and the cooling working medium 41a in the liquid state accumulates in the first chamber 415, the condensation flat tube 412 and the communication part 413 under the action of gravity. The heat transferred by the power device 21 to the cooling working medium 41a can be transferred to the external environment through the air flow flowing through the heat sink 41, so as to achieve heat dissipation of the power device 21 through the gas-liquid two-phase conversion of the cooling working medium 41a. The working medium pump 42 can drive the cooling working medium 41a in the liquid state to flow from the second chamber 416 or the communication part 413 to the first chamber 415 through the working medium pump 42, thereby realizing the recycling of the cooling working medium 41a, and ensuring that the cooling working medium 41a in the liquid state in the first chamber 415 always has sufficient amount, so as to stably dissipate heat of the power device 21. The design of the through hole 4141 provided at the top of the partition part 414 not only plays a guiding role for the cooling working medium 41a in the gaseous state flowing from the first chamber 415 to the second chamber 416, but also is beneficial to improve the efficiency of the cooling working medium 41a in the gaseous state flowing from the first chamber 415 to the second chamber 416, and is beneficial to improve the efficiency of heat dissipation of the power device 21.

[0117] Compared with the prior art, the radiator 41 integrates the functions of the evaporator and the condenser, so that the complex pipeline between the evaporator and the condenser can be avoided by welding or bonding, which is conducive to reducing the structural complexity of the radiator 41, improving the structural stability and reliability of the radiator 41, reducing the volume of the radiator 41, and facilitating the miniaturization design of the power conversion device 100. Moreover, the design of the gas-liquid two-phase conversion of the cooling working medium 41a and the recycling of the cooling working medium 41a in the application by combining gravity and the working medium pump 42 can reduce the influence of gravity on the design of the radiator 41, the bottom wall of the second chamber 416 can be not higher than the bottom wall of the first chamber 415, the second chamber 416 can be arranged without considering the position of the power device 21, and the bottom wall of the second chamber 416 can be not higher than the power device 21, which is conducive to reducing the volume of the radiator 41, improving the space utilization of the power conversion device 100, and facilitating the miniaturization design of the power conversion device 100. In addition, it is not only conducive to reducing the design difficulty of the radiator 41 and reducing the processing cost of the radiator 41, but also facilitates the flexible arrangement of the power device 21, reduces the installation difficulty of the power device 21 and the radiator 41, and reduces the processing cost of the power conversion device 100.

[0118] In addition, since the working medium pump 42 only needs to overcome the flow resistance of the cooling working medium 41a in the liquid state flowing from the second chamber 416 or the communication part 413 to the first chamber 415 through the working medium pump 42, the pressure head and service life requirements of the working medium pump 42 are low, the processing cost of the working medium pump 42 is low, the cooling cost is reduced, the processing cost of the power conversion device 100 is reduced, the speed of the gas-liquid two-phase conversion of the cooling working medium 41a is improved, and the heat dissipation efficiency of the power device 21 is improved.

[0119] In some embodiments, the working medium pump 42 also has a speed regulation function. Specifically, the working medium pump 42 is driven by a motor. By controlling the speed of the motor, the operating speed of the working medium pump 42 can be controlled to control the rate at which the cooling working medium 41a in the liquid state flows from the working medium pump 42 to the first chamber 415. When the power conversion device 100 is overloaded, the heat generated by the power device 21 during operation is transferred to the cooling working medium 41a in the first chamber 415 at a faster rate, the boiling speed of the cooling working medium 41a in the first chamber 415 is faster, and the cooling working medium 41a in the first chamber 415 is easy to dry. By controlling the operating speed of the working medium pump 42, the rate at which the cooling working medium 41a in the liquid state flows from the working medium pump 42 to the first chamber 415 is increased, the situation that the cooling working medium 41a in the first chamber 415 is dry is avoided, the stable heat dissipation of the radiator 41 to the power device 21 is ensured, and the service life of the power conversion device 100 is prolonged.

[0120] As shown in FIG. 3, in some embodiments, in the Y-axis direction, the magnetic device 23, the heat exchanger 60 and the heat sink 41 are located on one side of the first fan 50, and the magnetic device 23 and the heat exchanger 60 are located on both sides of the heat sink 41. Specifically, the magnetic device 23 is located on the side of the heat sink 41 away from the first fan 50, and the heat exchanger 60 is located between the first fan 50. Among them, the projection of the magnetic device 23 in the X-axis direction overlaps the projection of the air outlet hole 15 in the X-axis direction. In the Y-axis direction, the magnetic device 23, the heat exchanger 60 and the heat sink 41 are located on one side of the first fan 50, and the magnetic device 23 and the heat exchanger 60 are located on both sides of the heat sink 41. The design can make the first fan 50 drive the external airflow to flow into the second cavity 12 from the air inlet hole 14, and then flow out of the second cavity 12 from the air outlet hole 15 through the heat exchanger 60, the heat sink 41 and the magnetic device 23 in turn, realizing the heat dissipation of the power device 21, the magnetic device 23 and the electronic device 24, and the heat exchanger 60, the heat sink 41 and the magnetic device 23 share the air duct, which is conducive to improving the utilization rate of the first fan 50 and reducing the cost of heat dissipation.

[0121] In some embodiments, the magnetic device 23 is also provided with heat-conducting fins 231. Specifically, in the X-axis direction, the side of the magnetic device 23 away from the isolation cavity wall 13a is provided with heat-conducting fins 231. The design of the heat-conducting fins 231 is conducive to improving the heat dissipation area of the magnetic device 23 and improving the heat dissipation efficiency of the magnetic device 23.

[0122] As shown in FIG. 3 and FIG. 11, in some embodiments, the shell 10 is also provided with a heat exchange hole 17, which communicates with the first cavity 11 and the second cavity 12. Specifically, the heat exchange hole penetrates the isolation cavity wall 13a along the X-axis direction. The heat exchanger 60 includes a heat exchange cavity 60a, which communicates with the first cavity 11 through the heat exchange hole 17. And the heat exchanger 60 covers the heat exchange hole 17 to close the first cavity 11. The heat generated by the electronic device 24 during work is transferred to the heat exchange cavity 60a through the air in the first cavity 11 through the heat exchange hole 17. Exemplarily, the number of heat exchange holes 17 is multiple. Specifically, the number of heat exchange holes 17 is 2. In the Z-axis direction, the 2 heat exchange holes are located on both sides of the circuit board 22.

[0123] Further, the air outlet side of the second fan 70 faces the heat exchange hole 17. Specifically, the air outlet side of the second fan 70 faces one heat exchange hole 17. The second fan 70 can drive the air in the first cavity 11 to flow, so as to improve the efficiency of the air in the first cavity 11 flowing into the heat exchange cavity 60a through the heat exchange hole 17, which is conducive to improving the efficiency of the heat generated by the electronic device 24 during work being transferred to the heat exchanger 60, and improving the heat dissipation efficiency of the electronic device 24.

[0124] In the embodiments shown in FIG. 3 and FIG. 11, the heat exchanger 60 comprises a first heat exchange portion 61, a second heat exchange portion 62 and a third heat exchange portion 63. In the Z-axis direction, the first heat exchange portion 61 and the second heat exchange portion 62 are oppositely and spacedly arranged, and the third heat exchange portion 63 is fixedly connected between the first heat exchange portion 61 and the second heat exchange portion 62. For example, the number of the third heat exchange portion 63 is plural. Specifically, the number of the third heat exchange portion 63 is three. In the X-axis direction, the plural third heat exchange portions 63 are sequentially and spacedly arranged. In some other embodiments, the number of the third heat exchange portion 63 can also be one, two or more. The first heat exchange portion 61 covers one heat exchange hole 17 to close the first cavity 11, and the second heat exchange portion 62 covers another heat exchange hole 17 to close the first cavity 11.

[0125] The first heat exchange portion 61 comprises a first heat exchange sub-cavity 611. The second heat exchange portion 62 comprises a second heat exchange sub-cavity 621. The third heat exchange portion 63 comprises a third heat exchange sub-cavity 631. In the Z-axis direction, the third heat exchange sub-cavity 631 is communicated between the first heat exchange sub-cavity 611 and the second heat exchange sub-cavity 621. For example, the number of the third heat exchange sub-cavity 631 is plural. Specifically, the number of the third heat exchange sub-cavity 631 is two. In the Y-axis direction, the two third heat exchange sub-cavities 631 are sequentially and spacedly arranged. In some other embodiments, the number of the third heat exchange sub-cavity 631 can also be one, three or more. The first heat exchange sub-cavity 611 is communicated with one heat exchange hole 17. The second heat exchange sub-cavity 621 is communicated with another heat exchange hole 17. The heat exchange cavity 60a comprises the first heat exchange sub-cavity 611, the second heat exchange sub-cavity 621 and the third heat exchange sub-cavity 631. Specifically, the heat exchange cavity 60a comprises the first heat exchange sub-cavity 611, the second heat exchange sub-cavity 621 and six third heat exchange sub-cavities 631.

[0126] The heat generated by the electronic device 24 during operation is transferred to the air in the first cavity 11. The second fan 70 drives the air in the first cavity 11 to flow from one heat exchange hole 17 into the first heat exchange sub-cavity 611, from the first heat exchange sub-cavity 611 into the second heat exchange sub-cavity 621 through the plural third heat exchange sub-cavities 631, and from the second heat exchange sub-cavity 621 back to the first cavity 11 through another heat exchange hole 17. The heat generated by the electronic device 24 during operation is transferred to the heat exchange cavity 60a through the air in the first cavity 11, and the external airflow in the second cavity 12 flows into the heat exchanger 60 from the air inlet hole 14, flows out from the air outlet hole 15 through the plural third heat exchange portions 63 of the heat exchanger 60, so that the external airflow can transfer the heat generated by the electronic device 24 during operation to the external environment, thereby achieving heat dissipation of the electronic device 24.

[0127] In some embodiments, the heat exchanger 60 is further provided with heat exchange fins 64. Specifically, in the X-axis direction, the heat exchange fins 64 are arranged between two adjacent third heat exchange portions 63. For example, a plurality of heat exchange fins 64 are arranged between two adjacent third heat exchange portions 63. In the Z-axis direction, the plurality of heat exchange fins 64 are arranged in sequence with intervals. The heat exchange fins 64 are designed to increase the heat dissipation area of the third heat exchange portion 63 and the external airflow, improve the heat dissipation efficiency of the third heat exchange portion 63, improve the heat dissipation efficiency of the heat exchanger 60, and improve the heat dissipation efficiency of the electronic device 24.

[0128] Referring to FIGS. 12 and 13, and in combination with FIG. 3, FIG. 12 is a structural schematic diagram of another power conversion device 100 provided by an embodiment of the present application. FIG. 13 is a structural schematic diagram of the heat dissipation assembly 30 (omitting the first fan 50, the heat exchanger 60, and the second fan 70) of the power conversion device 100 shown in FIG. 12 in cooperation with the power device 21.

[0129] As shown in FIGS. 3, 12, and 13, the embodiment shown in FIG. 12 is similar to the embodiment shown in FIG. 3 in structure, and the difference between the two is the installation position of the working medium pump 42. In the embodiment shown in FIG. 12, in the direction of gravity (i.e., the Y-axis direction), the bottom of the partition portion 414 is further provided with an installation hole 4142, which is in communication with the first chamber 415 and the second chamber 416. The working medium pump 42 is accommodated in the installation hole 4142. Specifically, the installation hole 4142 penetrates the partition portion 414 along the X-axis direction. In the Y-axis direction (i.e., the direction of gravity), the installation hole 4142 is located below the through hole 4141 and below the power device 21. The installation hole 4142 extends along the Y-axis direction towards the fourth connecting wall 4114. The inlet 421 of the working medium pump 42 faces the second chamber 416, and the outlet 422 of the working medium pump 42 faces the first chamber 415.

[0130] The design that the working medium pump 42 is accommodated in the installation hole 4142 integrates the working medium pump 42 in the heat sink 41, which can avoid the connection between the working medium pump 42 and the heat sink 41 through a pipeline, improve the structural reliability between the working medium pump 42 and the heat sink 41, reduce the difficulty of accommodating the heat sink 41 and the working medium pump 42 in the second cavity 12, improve the space utilization of the second cavity 12, and reduce the processing cost of the power conversion device 100.

[0131] Please refer to FIG. 14, FIG. 15 and FIG. 16, and in combination with FIG. 3, FIG. 14 is a structural schematic diagram of another power conversion device 100 provided by an embodiment of the present application. FIG. 15 is a partial structural schematic diagram of the power conversion device 100 shown in FIG. 14 along the line E-E. FIG. 16 is a structural schematic diagram of the power conversion device 100 shown in FIG. 15 along the line F-F. It should be noted that the dashed box in FIG. 16 schematically indicates the position of the power device 21.

[0132] As shown in FIG. 14, FIG. 15 and FIG. 16, the embodiment shown in FIG. 14 is similar in structure to the embodiment shown in FIG. 3, and the difference between the two is that there is a structural improvement between the plurality of condensing flat tubes 412, and the structure of the first chamber 415 is different. In the embodiment shown in FIG. 14, a heat dissipation fin 419 is further arranged between the two adjacent condensing flat tubes 412. The heat dissipation fin 419 is in contact with and fixedly connected to the two adjacent condensing flat tubes 412. The heat dissipation fin 419 is accommodated in the ventilation hole 4120. For example, the number of heat dissipation fins 419 between the two adjacent condensing flat tubes 412 can be multiple. The plurality of heat dissipation fins 419 are sequentially and spaced apart in the X-axis direction. The external airflow can flow through the condensing flat tube 412 from the ventilation hole 4120 between the two adjacent condensing flat tubes 412 to transfer the heat generated by the power device 21 during operation to the external environment, thereby achieving heat dissipation of the power device 21. The design of the heat dissipation fin 419 is beneficial to increasing the contact area of the condensing flat tube 412 with the external airflow, and is beneficial to improving the heat dissipation efficiency of the condensing flat tube 412 and the heat dissipation efficiency of the power device 21.

[0133] In the embodiment shown in FIG. 14, the first chamber 415 further includes a plurality of passages 4151, the plurality of passages 4151 are isolated by a partition plate 4152, each partition plate 4152 is fixedly connected to the cavity wall of the first chamber 415 and the partition 414 in the X-axis direction (i.e., the first direction), each passage 4151 is in communication with the through hole 4141, and the projection of the power device 21 in the X-axis direction (i.e., the first direction) overlaps the projection of the plurality of passages 4151 in the X-axis direction (i.e., the first direction). The passage 4151 accommodates the cooling working medium 41a in liquid state, and the liquid level of the cooling working medium 41a in liquid state in the passage 4151 is higher than the power device 21 in the direction of gravity.

[0134] Further, the plurality of partition plates 4152 are sequentially and spacedly arranged along the Z-axis direction (i.e., the second direction), and the channels 4151 extend along the Y-axis direction (i.e., the direction of gravity). Specifically, each partition plate 4152 is in contact with and fixedly connected to the first connecting wall 4111 and the partition portion 414. Each partition portion 414 is located on the side of the through hole 4141 facing the fourth connecting wall 4114 and is spacedly arranged from the fourth connecting wall 4114. For example, the plurality of partition plates 4152 include a first partition plate 4152a, a plurality of second partition plates 4152b, a third partition plate 4152c, a plurality of fourth partition plates 4152d, and a fifth partition plate 4152e, which are sequentially and spacedly arranged along the Z-axis direction. The first partition plate 4152a and the fifth partition plate 4152e are in contact with and fixedly connected to two fifth connecting walls 4115, respectively. Along the Z-axis direction, the first partition plate 4152a, the plurality of second partition plates 4152b, and the third partition plate 4152c are sequentially and spacedly arranged and form a plurality of first channels 4151a. The third partition plate 4152c, the plurality of fourth partition plates 4152d, and the fifth partition plate 4152e are sequentially and spacedly arranged and form a plurality of second channels 4151b.

[0135] For example, the number of power devices 21 is a plurality, and the plurality of power devices 21 include a plurality of first power devices 21a and a plurality of second power devices 21b. The plurality of first power devices 21a correspond to the plurality of first channels 4151a. Specifically, the projection of the first power device 21a on the X-axis direction overlaps the projection of the plurality of first channels 4151a on the X-axis direction. The plurality of second power devices 21b correspond to the plurality of second channels 4151b. For details, refer to the above description. In the direction of gravity, the liquid level of the cooling working medium 41a in each channel 4151 in liquid state is higher than each power device 21.

[0136] In the embodiment shown in FIG. 14, the cooling working medium 41a in the liquid state is contained in the plurality of channels 4151. The heat generated by the power devices 21 is transferred to the cooling working medium 41a in the liquid state in the plurality of channels 4151, the cooling working medium 41a in the liquid state absorbs heat to boil and form the cooling working medium 41a in the gaseous state, the cooling working medium 41a in the gaseous state flows to the second chamber 416 through the through hole 4141, the cooling working medium 41a in the gaseous state releases heat to condense and form the cooling working medium 41a in the liquid state, and the working medium pump 42 drives the cooling working medium 41a in the liquid state to flow into the plurality of channels 4151 of the first chamber 415 through the working medium pump 42. Specifically, the heat generated by the first power device 21a is transferred to the cooling working medium 41a in the liquid state in the plurality of first channels 4151a, and the heat generated by the second power device 21b is transferred to the cooling working medium 41a in the liquid state in the plurality of second channels 4151b. The cooling working medium 41a in the liquid state absorbs heat to boil and form the cooling working medium 41a in the gaseous state, and the cooling working medium 41a in the gaseous state flows to the second chamber 416 from one side of each channel 4151 toward the through hole 4141 through the through hole 4141. The cooling working medium 41a in the gaseous state releases heat to condense and form the cooling working medium 41a in the liquid state. The working medium pump 42 drives the cooling working medium 41a in the liquid state to flow into each channel 4151 from the side of each channel 4151 away from the through hole 4141 through the working medium pump 42.

[0137] The first chamber 415 is divided into a plurality of channels 4151 by the partition plate 4152, which can uniformly disperse the pressure generated by the liquid working medium in each channel 4151, and can also withstand a certain pressure, so that the stability of the entire heat dissipation substrate 411 is better, which is conducive to improving the structural stability and reliability of the heat sink 41.

[0138] The design that the channels 4151 extend along the direction of gravity is conducive to reducing the flow resistance of the cooling working medium 41a in the liquid state flowing in the channels 4151, reducing the difficulty of driving the liquid level of the cooling working medium 41a in the liquid state to be higher than the power devices 21, reducing the head requirement and service life requirement of the working medium pump 42, reducing the processing cost of the working medium pump 42, and reducing the processing cost of the power conversion device 100.

[0139] It can be understood that in this embodiment, the design that the heat dissipation fins 419 are arranged between the adjacent two condensation flat tubes 412 and the structural improvement of the first chamber 415 are applied to the scenario that the working medium pump 42 is located outside the heat sink 41. The design that the heat dissipation fins 419 are arranged between the adjacent two condensation flat tubes 412 and the structural improvement of the first chamber 415 can also be applied to the scenario that the working medium pump 42 is contained in the heat sink 41.

[0140] Please refer to FIG. 17, FIG. 18 and FIG. 19, and combine with FIG. 3, FIG. 17 is a structural schematic diagram of another power conversion device 100 provided by the embodiment of the present application. FIG. 18 is a structural schematic diagram of the heat dissipation assembly 30 (omitting the first fan 50, the heat exchanger 60 and the second fan 70) of the power conversion device 100 shown in FIG. 17 cooperating with the power device 21. FIG. 19 is a structural schematic diagram of the heat sink 41 shown in FIG. 18 along the line G-G. It should be noted that the dashed box in FIG. 19 schematically indicates the position of the power device 21.

[0141] As shown in FIG. 17, FIG. 18 and FIG. 19, the embodiment shown in FIG. 17 is similar to the embodiment shown in FIG. 3 in structure, and the difference between the two is that the structure of the first chamber 415 is different. In the embodiment shown in FIG. 17, the first chamber 415 further includes a plurality of channels 4151, the plurality of channels 4151 are isolated by a plurality of partition plates 4152, each partition plate 4152 is fixedly connected with the cavity wall of the first chamber 415 and the partition portion 414 in the X-axis direction (i.e. the first direction), each channel 4151 is in communication with the through hole 4141, and the projection of the power device 21 in the X-axis direction (i.e. the first direction) overlaps the projection of the plurality of channels 4151 in the X-axis direction (i.e. the first direction). The channel 4151 contains the cooling working medium 41a in liquid state, and the liquid level of the cooling working medium 41a in liquid state in the channel 4151 is higher than the power device 21 in the direction of gravity.

[0142] Further, the plurality of partition plates 4152 are sequentially and spacedly arranged along the Y-axis direction (i.e. the direction of gravity), and the channel 4151 extends along the Z-axis direction (i.e. the second direction). In this embodiment, the plurality of channels 4151 include a plurality of first channels 4151a and a plurality of second channels 4151b, the plurality of second channels 4151b and the plurality of first channels 4151a are sequentially arranged in the Y-axis direction (i.e. the direction of gravity), one end of each first channel 4151a is in communication with one end of each second channel 4151b, and the other end of each second channel 4151b is in communication with the through hole 4141.

[0143] Specifically, the plurality of partition plates 4152 include a first partition plate 4152a, a plurality of second partition plates 4152b, a third partition plate 4152c, a plurality of fourth partition plates 4152d and a fifth partition plate 4152e. From the side of the through hole toward the fourth connecting wall 4114, the first partition plate 4152a, the plurality of second partition plates 4152b, the fourth partition plate 4152d, the plurality of third partition plates 4152c and the fifth partition plate 4152e are sequentially and spacedly arranged along the Y-axis direction. Each partition plate 4152 is in contact with and fixedly connected with the first connecting wall 4111 and the partition portion 414.

[0144] The first partition plate 4152a, the fourth partition plate 4152d and the fifth partition plate 4152e are in contact with and fixedly connected to two fifth connecting walls 4115. Each second partition plate 4152b and each third partition plate 4152c are arranged at intervals from the two fifth connecting walls 4115. The fourth partition plate 4152d, the plurality of third partition plates 4152c and the fifth partition plate 4152e are arranged at intervals in sequence and form a plurality of first channels 4151a. The first partition plate 4152a, the plurality of second partition plates 4152b and the fourth partition plate 4152d are arranged at intervals in sequence and form a plurality of second channels 4151b.

[0145] The first partition plate 4152a is provided with a first flow-through hole 4153 penetrating the first partition plate 4152a along the Y-axis direction, and the first flow-through hole 4153 is in communication with the through hole 4141. The fourth partition plate 4152d is provided with a second flow-through hole 4154 penetrating the fourth partition plate 4152d along the Y-axis direction. The fifth partition plate 4152e is provided with a third flow-through hole 4155 penetrating the fifth partition plate 4152e along the Y-axis direction. In the Z-axis direction, the first flow-through hole 4153 and the third flow-through hole 4155 are located on one side of each second partition plate 4152b and each third partition plate 4152c, and the second flow-through hole 4154 is located on the other side of each second partition plate 4152b and each third partition plate 4152c. One end of each first channel 4151a is in communication with one end of each second channel 4151b through the second flow-through hole 4154, and the other end is in communication with the third flow-through hole 4155. The other end of each second channel 4151b is in communication with the through hole 4141.

[0146] For example, the number of power devices 21 is a plurality, and the plurality of power devices 21 includes a plurality of first power devices 21a and a plurality of second power devices 21b. The plurality of first power devices 21 corresponds to the plurality of first channels 4151a. The plurality of second power devices 21b corresponds to the plurality of second channels 4151b. In the direction of gravity, the liquid level of the cooling working medium 41a in liquid state in each channel 4151 is higher than each power device 21.

[0147] In the embodiment shown in FIG. 17, the heat generated by the first power device 21a is transferred to the cooling medium 41a in liquid state in the plurality of first channels 4151a, the heat generated by the second power device 21b is transferred to the cooling medium 41a in liquid state in the plurality of second channels 4151b, the cooling medium 41a in liquid state absorbs heat to boil and form the cooling medium 41a in gaseous state, the cooling medium 41a in gaseous state flows to the second chamber 416 through the first flow-through hole 4153 and the through hole 4141. The cooling medium 41a in gaseous state releases heat to condense and form the cooling medium 41a in liquid state, and the working medium pump 42 drives the cooling medium 41a in liquid state to flow from the third flow-through hole 4155 to each first channel 4151a and then to each second channel 4151b through the working medium pump 42.

[0148] The design that the channels 4151 extend along the second direction is conducive to increasing the difficulty of the cooling medium 41a in liquid state flowing from the channels 4151 to the second chamber 416 through the through hole 4141, conducive to keeping the cooling medium 41a in liquid state always higher than the power devices 21, conducive to increasing the efficiency of the heat generated by the power devices 21 when working to the cooling medium 41a, and conducive to increasing the heat dissipation efficiency of the power devices 21.

[0149] The working medium pump 42 drives the cooling medium 41a to flow through each first channel 4151a and then through each second channel 4151b, which plays a guiding role in the flow of the cooling medium 41a in the first chamber 415, conducive to reducing the difficulty of the liquid level of the cooling medium 41a in liquid state in the first chamber 415 being higher than each power device 21, conducive to reducing the head requirement and service life requirement of the working medium pump 42, conducive to reducing the processing cost of the working medium pump 42, and conducive to reducing the processing cost of the power conversion device 100. Moreover, the structure of the first chamber 415 is various and has low design cost, conducive to reducing the processing cost of the power conversion device 100.

[0150] It can be understood that in this embodiment, the structure of the first chamber 415 is applied to the scenario that the working medium pump 42 is located outside the heat sink 41, and the structure improvement of the first chamber 415 can also be applied to the scenario that the working medium pump 42 is accommodated in the heat sink 41.

[0151] Please refer to FIG. 20 and FIG. 21, and combine with FIG. 3, FIG. 20 is a structural schematic diagram of another power conversion device 100 provided by the embodiment of the present application. FIG. 21 is a structural schematic diagram of the heat dissipation assembly 30 (omitting the first fan 50, the heat exchanger 60 and the second fan 70) of the power conversion device 100 shown in FIG. 20 cooperating with the power device 21.

[0152] As shown in FIG. 3, FIG. 20 and FIG. 21, the embodiment shown in FIG. 20 is similar to the embodiment shown in FIG. 3, and the difference between the two is that the arrangement of the plurality of condensing flat tubes 412 is different, and the structure of the second chamber 416 is different. In the embodiment shown in FIG. 20, the plurality of condensing flat tubes 412 are arranged in the Y-axis direction. For example, the plurality of condensing flat tubes 412 include a first condensing flat tube 412a and a second condensing flat tube 412b, and the first condensing flat tube 412a is located above the second condensing flat tube 412b in the Y-axis direction (i.e. the direction of gravity). Each condensing flat tube 412a includes a plurality of flow channels 4121. For details, please refer to the related description of the embodiment shown in FIG. 3, which will not be repeated here.

[0153] In the embodiment shown in FIG. 20, the second chamber 416 is also provided with a reinforcing portion 4160, so that the second chamber 416 is divided into a first sub-chamber 4161 and a second sub-chamber 4162, and the first sub-chamber 4161 is located above the second sub-chamber 4162 in the Y-axis direction (i.e. the direction of gravity), and the first sub-chamber 4161 is in communication with the first chamber 415 through the through hole 4141. The first sub-chamber 4161 is in communication with the communication portion 413 through a part of the flow channels 4121, and the second sub-chamber 4162 is in communication with the communication portion 413 through another part of the flow channels 4121.

[0154] Specifically, the reinforcing portion 4160 is in contact and fixed connection with the partition portion 414 and the second connecting wall 4112, and is in contact and fixed connection with the two fifth connecting walls 4115. The reinforcing portion 4160 is spaced apart from the third connecting wall 4113 and the fourth connecting wall 4114. The first sub-chamber 4161 is in communication with the flow-through chamber 4130 (i.e. the communication portion 413) through the plurality of flow channels 4121 of the second condensing flat tube 412a. The second sub-chamber 4162 is in communication with the flow-through chamber 4130 (i.e. the communication portion 413) through the plurality of flow channels 4121 of the first condensing flat tube 412a.

[0155] The heat generated by the power device 21 is transferred to the cooling working medium 41a in the liquid state in the first chamber 415, and the cooling working medium 41a in the liquid state in the first chamber 415 absorbs heat to boil and form the cooling working medium 41a in the gaseous state, which flows from the first chamber 415 to the first sub-chamber 4161 through the through hole 4141, and then flows from the first sub-chamber 4161 to the communication part 413 through a part of the flow channel 4121. The cooling working medium 41a in the gaseous state releases heat to condense and form the cooling working medium 41a in the liquid state in the first sub-chamber 4161, the flow channel 4121 between the first sub-chamber 4161 and the communication part 413, and the communication part 413, and the cooling working medium 41a in the liquid state flows to the communication part 413 under the action of gravity. The second sub-chamber 4162, the communication part 413, and the flow channel 4121 between the communication part 413 and the second sub-chamber 4162 all contain the cooling working medium 41a in the liquid state. The design of the reinforcing part 4160 is beneficial to improving the strength of the cavity wall of the second chamber 416, the structural stability and reliability of the heat dissipation substrate 411, and the structural stability and reliability of the heat sink 41.

[0156] In the embodiment shown in FIG. 20, the cooling working medium 41a in the gaseous state is transferred to the first sub-chamber 4161 through the through hole 4141, and then flows from the first sub-chamber 4161 to the flow-through cavity 4130 through the plurality of flow channels 4121 of the first condensation flat tube 412a. The cooling working medium 41a in the gaseous state releases heat to condense and form the cooling working medium 41a in the liquid state in the first sub-chamber 4161, the first condensation flat tube 412a, and the flow-through cavity 4130, and the cooling working medium 41a in the liquid state flows to the bottom of the flow-through cavity 4130 under the action of gravity. The second sub-chamber 4162, the flow-through cavity 4130, and the flow channel 4121 of the second condensation flat tube 412b all contain the cooling working medium 41a in the liquid state. The working medium pump 42 drives the cooling working medium 41a in the liquid state in the second sub-chamber 4162 or the flow-through cavity 4130 to flow to the first chamber 415 through the working medium pump 42.

[0157] In the embodiment shown in FIG. 20, the first sub-chamber 4161 and the second sub-chamber 4162 are communicated with the communication part 413 through different condensation flat tubes 412. In some other embodiments, the first sub-chamber 4161 and the second sub-chamber 4162 can also be communicated through the same condensation flat tube 412. For example, in each condensation flat tube 412, the first sub-chamber 4161 is communicated with the communication part 413 through the flow channel 4121 located above the condensation flat tube 412, and the second sub-chamber 4162 is communicated with the communication part 413 through the flow channel 4121 located below the condensation flat tube 412.

[0158] It can be understood that the structural improvement of the second chamber 416 in the embodiment shown in FIG. 20 can be applied to any of the embodiments shown in FIGS. 2 to 19.

Claims

1. A power conversion device, characterized by, The application relates to a power conversion device. The device comprises a shell, a power device, a heat dissipation assembly, and a working medium pump. The shell comprises a first cavity and a second cavity, and the first cavity is spaced apart from the second cavity in a first direction. The first cavity and the second cavity are communicated with a connecting hole, an air inlet hole and an air outlet hole. The power device is accommodated in the first cavity. The heat dissipation assembly comprises a heat dissipation base plate, a plurality of condensation flat tubes and a connecting part. The heat dissipation base plate is in contact with the power device through the connecting hole and covers the connecting hole to seal the first cavity.

2. The power conversion device of claim 1, wherein, The heat dissipation base plate comprises a first chamber and a second chamber divided by a partition.

3. The power conversion device of claim 1, wherein, The first chamber is located on the side of the second chamber close to the power device in the first direction.

4. The power conversion device of claim 1, wherein, The top of the partition is provided with a through hole in the direction of gravity.

5. The power conversion device of claim 4, wherein, The first chamber is communicated with the second chamber through the through hole.

6. The power conversion device of claim 1, wherein, The plurality of condensation flat tubes are located on the side of the heat dissipation base plate away from the power device and are spaced apart.

7. A power conversion device according to any one of claims 1-6, characterized in that, The plurality of condensation flat tubes are communicated with each other through the connecting part. The second chamber is communicated with the plurality of condensation flat tubes. The first chamber, the second chamber and the condensation flat tubes are used for accommodating cooling working medium for gas-liquid phase conversion. The working medium pump is used for driving the cooling working medium in liquid state to flow to the first chamber. In the direction of gravity, the liquid level of the cooling working medium in liquid state in the first chamber is higher than the power device. In the direction of gravity, the liquid level of the cooling working medium in liquid state in the first chamber is higher than the cooling working medium in liquid state in the second chamber. The working medium pump is located outside the heat dissipation base plate. The working medium pump comprises an inlet and an outlet. The power conversion device further comprises an input pipe body and an output pipe body. The inlet of the working medium pump is communicated with the second chamber or the connecting part through the input pipe body. The outlet of the working medium pump is communicated with the first chamber through the output pipe body. The heat dissipation base plate is further provided with an input pipe body mounting hole and an output pipe body mounting hole. In the direction of gravity, the input pipe body mounting hole is located below the second chamber or the connecting part. The output pipe body mounting hole is located below the first chamber. The working medium pump is located below the heat dissipation base plate. The input pipe body is fitted in the input pipe body mounting hole. The output pipe body is fitted in the output pipe body mounting hole. In the direction of gravity, the bottom of the partition is further provided with a mounting hole. The mounting hole is communicated with the first chamber and the second chamber. The working medium pump is accommodated in the mounting hole. The connecting part comprises a flow-through cavity. The connecting part is fixedly connected with the plurality of condensation flat tubes. The flow-through cavity is communicated with the plurality of condensation flat tubes.

8. The power conversion device of claim 7, wherein, The plurality of condensing flat tubes are arranged in sequence and spaced apart in a second direction to form a ventilation hole, the second direction being perpendicular to the first direction and the direction of gravity.

9. The power conversion device of claim 7, wherein, Each of the condensing flat tubes comprises a plurality of flow channels extending in the first direction, adjacent flow channels being separated by a baffle, and the plurality of flow channels are in communication with the second chamber and the communication part.

10. The power conversion device of claim 9, wherein, The second chamber further comprises a reinforcing part, so that the second chamber is divided into a first sub-chamber and a second sub-chamber, the first sub-chamber being located above the second sub-chamber in the direction of gravity, and the first sub-chamber being in communication with the first chamber through the through hole; the first sub-chamber is in communication with the communication part through a part of the flow channels, and the second sub-chamber is in communication with the communication part through another part of the flow channels.

11. The power conversion device according to any one of claims 1 to 10, characterized by, The first chamber further comprises a plurality of channels, the plurality of channels being separated by a partition plate, each of the partition plates being fixedly connected to the chamber wall of the first chamber and the partition part in the first direction, and each of the channels being in communication with the through hole, and the projection of the power device in the first direction overlapping the projection of the plurality of channels in the first direction.

12. The power conversion device of claim 11, wherein, The plurality of partition plates are arranged in sequence and spaced apart in a second direction, and the channels extend in the direction of gravity, the second direction being perpendicular to the first direction and the direction of gravity.

13. The power conversion device of claim 11, wherein, The plurality of partition plates are arranged in sequence and spaced apart in the direction of gravity, and the channels extend in a second direction, the second direction being perpendicular to the first direction and the direction of gravity.

14. The power conversion device of claim 13, wherein, In the second direction, each of the partition plates is arranged spaced apart from the chamber wall of the first chamber, and the plurality of channels comprise a plurality of first channels and a plurality of second channels, the plurality of second channels and the plurality of first channels being arranged in sequence in the direction of gravity, one end of each of the first channels being in communication with one end of each of the second channels, and the other end of each of the second channels being in communication with the through hole.

15. A heat dissipating assembly for heat exchange with a power device, characterized by, The heat sink comprises a heat dissipation base plate, a plurality of condensing flat tubes and a communication part. The heat dissipation base plate exchanges heat with the power device, and the heat dissipation base plate comprises a first chamber and a second chamber divided by a partition part, the first chamber being located on the side of the second chamber close to the power device in a first direction, the first direction being different from the direction of gravity; in the direction of gravity, the top of the partition part is provided with a through hole, and the first chamber is in communication with the second chamber through the through hole; The plurality of condensing flat tubes are arranged spaced apart on the side of the heat dissipation base plate away from the power device, the plurality of condensing flat tubes are in communication with each other through the communication part, and the second chamber is in communication with the plurality of condensing flat tubes; The first chamber, the second chamber and the condensing flat tubes are used to accommodate cooling working medium for gas-liquid two-phase conversion, and the working medium pump is used to drive the cooling working medium in liquid state to flow to the first chamber.

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