CN118632476B

CN118632476B - Power conversion equipment

Info

Publication number: CN118632476B
Application number: CN202410564999.6A
Authority: CN
Inventors: 任俊衡; 李霁阳; 洪芳军; 孙发明
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2024-04-30
Filing date: 2024-04-30
Publication date: 2026-04-24
Anticipated expiration: 2044-04-30
Also published as: WO2025228241A1; WO2025228241A9; CN121241668A; CN118632476A

Abstract

This application provides a power conversion device, relating to the field of power electronics technology. The power conversion device includes a housing, a circuit board, a heat sink, and a first heat exchanger. A power cavity is formed inside the housing, and a heat dissipation cavity is formed outside the housing. The housing includes a partition between the power cavity and the heat dissipation cavity, with an opening on the partition. The circuit board is disposed within the power cavity, and a first power device is located on the side facing the opening. The heat sink is disposed within the heat dissipation cavity and includes a first substrate and a first heat dissipation section. The first substrate is located at the opening and contacts the first power device. A first gas-liquid channel is provided within the first substrate, and a second gas-liquid channel communicating with the first gas-liquid channel is provided within the first heat dissipation section. A cooling medium for gas-liquid conversion is provided within the first gas-liquid channel. The first heat exchanger is located within the power cavity or the heat dissipation cavity. This technical solution enables targeted heat dissipation of components in the power conversion device that generate significant heat, ensuring stable operation of the power conversion device.

Description

Power conversion apparatus

Technical Field

The application relates to the technical field of power electronics, in particular to power conversion equipment.

Background

The inverter is a power conversion device capable of converting direct current into alternating current, and the power conversion device such as the inverter generates serious heat in the use process. With the development of the age, the heat dissipation demand for power conversion devices such as inverters has increased dramatically.

In the related art, the whole power conversion device is cooled by means of integral cooling, but the power conversion device includes a plurality of devices with larger power, such as a high-power chip. The device has serious heating, and a heat dissipation mode of a related technology is adopted, so that the device cannot be subjected to accurate heat dissipation, and the operation stability of power conversion equipment is affected.

Disclosure of Invention

The application provides power conversion equipment, which can conduct targeted heat dissipation on devices with serious heat in the power conversion equipment, so that the power conversion equipment can stably operate.

In order to achieve the above purpose, the application adopts the following technical scheme:

The application provides power conversion equipment, which comprises a shell, a circuit board, a radiator and a first heat exchanger, wherein a sealed power cavity is formed in the shell, the shell is provided with an open and ventilated heat dissipation cavity, the shell comprises a partition plate positioned between the power cavity and the heat dissipation cavity, the protection level of the power cavity is higher than that of the heat dissipation cavity, an opening is arranged on the partition plate, the circuit board is arranged in the power cavity, a first power device is arranged on one side of the circuit board facing the opening, the first power device forms a power conversion circuit of the power conversion equipment so as to perform power conversion on direct current input by the power conversion equipment, the radiator is arranged in the heat dissipation cavity and comprises a first substrate and a first heat dissipation part, the first substrate is arranged at the opening and is in heat conduction contact with the first power device in the heat dissipation cavity, the first heat dissipation part extends outwards from the first substrate, a first gas-liquid channel is arranged in the first substrate, a second gas-liquid channel communicated with the first gas-liquid channel is arranged in the first heat dissipation part, a cooling working medium used for gas-liquid conversion is arranged in the first gas-liquid channel, the first gas-liquid channel is arranged at an included angle of 90 DEG or more than 90 DEG, the first heat dissipation part is arranged on one side of the power conversion circuit is arranged in the heat dissipation cavity, and is opposite to the first heat dissipation device, and is used for heat exchange of the heat exchange device.

When the first power device in the power conversion equipment generates heat seriously, heat on the first power device can be transferred to the first substrate, and the cooling working medium in the first substrate is heated, after the liquid cooling working medium in the first gas-liquid channel is heated, at least part of the cooling working medium can become gaseous, the gaseous cooling working medium flows (rises) to the second gas-liquid channel of the first heat dissipation part, the open ventilation heat dissipation cavity is convenient for heat exchange between the cooling working medium in the first heat dissipation part and the outside, so that the gaseous cooling working medium can be quickly cooled and condensed in the first heat dissipation part, gradually changed into the liquid cooling working medium, then flows back into the first substrate, and is circulated in such a way, and continuously dissipates heat for the first power device. The application can ensure that the power conversion equipment can stably operate by carrying out targeted heat dissipation on the device (such as the first power device) with serious heat generation.

In addition, the power cavity is arranged in a sealing mode, the protection level is higher than that of the heat dissipation cavity, and the possibility that external impurities enter the power cavity can be reduced. And the first base plate sets up in the opening part, can make first base plate and first power device contact, also can play and shelter from open-ended effect, further reduced the possibility that heat dissipation chamber and power chamber are mutual interference, make the circuit board can set up in the relatively stronger chamber of protective capability, when carrying out the heat dissipation to the heating device, ensured the safety of other devices, reduced the risk that power conversion equipment broke down.

And the circuit board is arranged in the power cavity, when the power conversion equipment operates, the circuit board and electronic devices on the circuit board generate heat seriously, so that the temperature in the power cavity is higher, and the first heat exchanger is arranged to enable hot air in the power cavity to exchange heat with cold air in the heat dissipation cavity, so that the temperature in the power cavity is reduced, and the power conversion equipment can operate stably.

In an alternative embodiment, the first substrate protrudes below the first heat dissipation portion, and the first power device is at least partially located below the first heat dissipation portion.

The overlapping area of the first heat dissipation part and the first power device is smaller, so that the first heat dissipation part has more areas for exchanging heat with air in the heat dissipation cavity, the influence of the heat of the first power device on the condensation cooling working medium of the first heat dissipation part is reduced, the cooling working medium can be rapidly condensed in the first heat dissipation part, and the heat dissipation effect of the radiator is improved.

In an alternative embodiment, the first heat exchanger is located in the power cavity, a first heat exchange channel is formed in the first heat exchanger and is isolated from the power cavity, the first heat exchange channel is provided with an inlet and an outlet which are arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are communicated with the heat dissipation cavity.

Air in the heat dissipation cavity can enter the first heat exchange channel, then heat exchange is carried out between the air in the heat dissipation cavity and hot air in the power cavity through the first heat exchanger, and the heat dissipation cavity is open and ventilated, so that external air can continuously enter the first heat exchange channel, the temperature in the power cavity is reduced, and the power conversion equipment can stably operate.

In an alternative embodiment, the first heat exchanger is located in the heat dissipation cavity, a first heat exchange channel is formed in the first heat exchanger, the first heat exchange channel is isolated from the heat dissipation cavity, the first heat exchange channel is provided with an inlet and an outlet which are arranged on the first heat exchanger, and the inlet and the outlet of the first heat exchange channel are communicated with the power cavity.

The first heat exchanger can enable hot air in the power cavity to enter the first heat exchange channel, then the hot air exchanges heat with air in the heat dissipation cavity in the first heat exchanger, the heat dissipation cavity is arranged to be of an open ventilation structure, the air in the first heat exchange channel exchanges heat with cold air sufficient for the outside, the temperature in the power cavity is reduced, and the power conversion equipment can stably operate. In addition, the first heat exchanger is arranged in the heat dissipation cavity, so that the heat dissipation efficiency can be improved, and the heat dissipation speed is accelerated.

In an alternative embodiment, the first substrate protrudes below the first heat dissipating portion, and the first heat exchanger is at least partially located between a portion of the first substrate protruding the first heat dissipating portion and the first heat dissipating portion.

In order to enable the first power device to be at least partially located below the first heat dissipation portion, the first substrate extends downwards and forms a space with the first heat dissipation portion, and the first heat exchanger is installed in the space, so that the radiator and the first heat exchanger can be installed more compactly, and occupation of a heat dissipation cavity space is reduced.

In an alternative embodiment, the first heat exchanger is located in the heat dissipation cavity, the first heat exchanger includes a heat conducting plate and heat dissipation fins that are connected to each other, the heat conducting plate is attached to the first substrate in a heat conducting manner, and a fan is disposed in the heat dissipation cavity and is used for generating air flow through the heat dissipation fins.

The temperature of the electronic device is increased, so that the temperature of the power cavity is increased, heat in the power cavity is transferred to the heat conducting plate through the first substrate, and the heat conducting plate transfers the heat to the heat radiating fins. The fan blows air towards the radiating fins, and the radiating cavity is open and ventilated, so that heat on the radiating fins can be blown out of the radiating cavity through the air, namely, the heat is blown to the outside, and the fan continuously rotates, so that continuous heat radiation of the radiating fins can be realized, namely, the heat radiation of electronic devices in the power cavity is indirectly realized.

In an alternative embodiment, the first substrate protrudes below the first heat dissipation portion, and the heat conducting plate is thermally bonded to a portion of the first substrate protruding above the first heat dissipation portion, and the heat dissipation fins are located below the first heat dissipation portion.

The first substrate downwards extends and forms a space with the first heat dissipation part, the first heat exchanger is arranged in the space, the radiator and the first heat exchanger can be arranged more compactly, and the occupation of the space of the heat dissipation cavity is reduced. And the first power device is contacted with the protruding part of the first substrate, and the heat conducting plate is contacted with the protruding part of the first substrate to be matched with the heat radiating fins, so that heat radiation of the first power device can be better realized.

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

Under the condition that the first power device and the second power device have height difference, the second substrate and the second heat dissipation part can better dissipate heat for the second power device, and the possibility that the normal operation of the power conversion equipment is affected due to serious heat generation of the second power device is reduced. In addition, the power cavity and the heat dissipation cavity are distributed along the first direction, and the first substrate and the second substrate are distributed along the vertical direction, so that the size of the heat dissipation device in the first direction can be reduced, namely the size of the heat dissipation cavity in the first direction is reduced, and the size of the power conversion device in the first direction is reduced.

In an alternative embodiment, the power conversion device further includes a second heat exchanger, the second heat exchanger is used for transferring heat in the power cavity to the heat dissipation cavity, the first heat exchanger and the second heat exchanger are both arranged in the heat dissipation cavity, the first heat dissipation portion and the second heat dissipation portion are distributed along the vertical direction, the first substrate protrudes towards the lower side of the first heat dissipation portion, the second substrate protrudes towards the lower side of the second heat dissipation portion, one of the first heat exchanger and the second heat exchanger is located between the first heat dissipation portion and the second heat dissipation portion, and the other one of the first heat dissipation portion and the second heat dissipation portion is located below the lower one of the first heat dissipation portion and the second heat dissipation portion.

The hot air in the power cavity can exchange heat with the air in the heat dissipation cavity through the first heat exchanger and the second heat exchanger, so that the temperature in the power cavity can be further reduced, and the power conversion equipment can stably operate. Since the first substrate protrudes below the first heat dissipation portion and the second substrate protrudes below the second heat dissipation portion, there is a space left below both the first heat dissipation portion and the second heat dissipation portion. When the first heat exchanger and the second heat exchanger are arranged, the surplus space can be fully utilized, so that the installation of the radiator, the first heat exchanger and the second heat exchanger is more compact, the space in the radiating cavity is fully utilized, and the size of the power device in the first direction is reduced.

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

Hot air in the power cavity enters the first heat exchanger and the second heat exchanger through the first connecting pipe respectively, and after heat exchange between the hot air in the first heat exchanger and the hot air in the second heat exchanger and the air in the heat dissipation cavity, the hot air uniformly enters the second connecting pipe and returns to the power cavity through the second connecting pipe. The first heat exchanger and the second heat exchanger are mutually communicated and fixed through the first connecting pipe and the second connecting pipe, so that the integration level of the first heat exchanger and the second heat exchanger is improved, the first heat exchanger and the second heat exchanger are not required to be respectively communicated with the power cavity, and unified disassembly and assembly of the first heat exchanger and the second heat exchanger in the heat dissipation cavity are facilitated.

In an alternative embodiment, the first heat exchange channel and the second heat exchange channel extend along the second direction, the first connecting pipe and the second connecting pipe are respectively located at a lower one of the first heat dissipation part and the second heat dissipation part, and the first direction, the second direction and the vertical direction are perpendicular to each other at different sides in the second direction.

The first heat dissipation part, the first heat exchanger, the second heat dissipation part and the second heat exchanger are alternately distributed, the upper space and the lower space of the lower one of the first heat dissipation part and the second heat dissipation part are respectively utilized by the first heat exchanger and the second heat exchanger, and the space at two sides of the lower one of the first heat dissipation part and the second heat dissipation part is respectively utilized by the first connecting pipe and the second connecting pipe. Through the layout mode, the space of the heat dissipation cavity can be utilized more fully, and the size of the power device is reduced.

In an alternative embodiment, the power conversion device further comprises a protective cover, the heat dissipation cavity is formed in the protective cover, the heat dissipation hole comprises an air inlet hole and an air outlet hole, one of the air inlet hole and the air outlet hole is located below the radiator, the other one of the air inlet hole and the air outlet hole is located above the radiator, a fan is arranged in the heat dissipation cavity and used for driving air entering through the air inlet hole to be discharged from the air outlet hole.

Under the effect of the fan, wind outside the protective cover can enter from the air inlet hole and be discharged from the air outlet hole, and the air inlet hole and the air outlet hole are respectively positioned at the upper side and the lower side of the radiator, so that the external wind can fully pass through the radiator, and the radiating effect of the radiator is improved.

In an alternative embodiment, the first heat dissipation portion includes the first condenser pipe that a plurality of intervals set up, and the second heat dissipation portion includes the second condenser pipe that a plurality of intervals set up, all is provided with a plurality of fins between two adjacent first condenser pipes to and between two adjacent second condenser pipes, in first heat dissipation portion and the second heat dissipation portion, the quantity of the fin that one set up nearer to the fresh air inlet is less than the quantity of the fin that one set up farther to the fresh air inlet.

The closer the wind temperature to the air inlet hole is, the lower the wind temperature to the air inlet hole is, the heat exchange can be carried out when the wind passes through one of the first heat dissipation part and the second heat dissipation part, which is closer to the air inlet hole, and the temperature of the wind after heat exchange is increased, namely, the closer the wind temperature to the air outlet hole is in the heat dissipation cavity, and the higher the temperature of the wind is. The first radiating part and the second radiating part are arranged with thinner fins, so that a great amount of wind passes through the fins, and the fins arranged with thicker fins, which are far away from the air inlet, strengthen the radiating capacity, so that the vertically arranged first radiating part and second radiating part can radiate heat evenly.

In an alternative embodiment, the dimension of one of the first heat dissipating portion and the second heat dissipating portion, which is closer to the air inlet, is smaller than the dimension of one of the first heat dissipating portion and the second heat dissipating portion, which is farther from the air inlet, in the first direction.

By adopting the arrangement mode with different lengths, more cold air can be blown to one of the first heat dissipation part and the second heat dissipation part far away from the air inlet, the whole heat dissipation capacity of the radiator is enhanced, and the heat dissipation of the first heat dissipation part and the second heat dissipation part is balanced.

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

Through the design mode, when the first gas-liquid channel is arranged along the vertical direction, the second gas-liquid channel is inclined obliquely upwards from the first gas-liquid channel, so that liquid in the first heat dissipation part flows back into the first substrate, and the possibility that liquid cooling working medium is retained in the first heat dissipation part is reduced.

In an alternative embodiment, the first power device is fixedly connected with the first substrate through a bolt, a through hole is formed in the circuit board and used for allowing the head of the bolt to pass through, the rod of the bolt penetrates through the first power device and is in threaded connection with the first substrate, and the head of the bolt is in butt joint with the surface, deviating from the first substrate, of the first power device.

The first power device is fixedly connected with the first substrate, so that the first power device is fully contacted with the first substrate, the possibility of gaps between contact surfaces of the first power device and the first substrate is reduced, the first power device is tightly attached to the first substrate, and the heat dissipation effect of the first power device is better. In addition, the head of the bolt is abutted against the first power device instead of the circuit board, so that the damage to the circuit board when the bolt is fixed can be reduced, and the influence on the circuit board when the first power device is connected with the first substrate is reduced.

In an alternative embodiment, a portion of the first substrate faces the plate surface of the separator, and the first substrate closes at least a portion of the opening.

The heat dissipation cavity is communicated with the outside through the heat dissipation hole, and external impurities can possibly enter the heat dissipation cavity, and if the impurities in the heat dissipation cavity enter the power cavity, normal operation of the circuit board and devices (such as electronic devices) on the circuit board can be affected. The part of the first substrate is arranged opposite to the plate surface of the partition plate, so that a part of the first substrate and the partition plate are overlapped, at least part of the opening can be blocked by the first substrate, the possibility that gas in the heat dissipation cavity enters the power cavity through the opening is reduced, the possibility that external impurities affect the operation of the circuit board and devices on the circuit board is reduced, the power cavity and the heat dissipation cavity are independent of each other, and a high protection cavity (namely, a power cavity) is formed in the power conversion equipment to place the circuit board, so that the normal operation of the power conversion equipment is facilitated.

In an alternative embodiment, the inner wall surface of the first substrate surrounding the first gas-liquid channel comprises a first wall surface and a second wall surface, the first wall surface and the second wall surface are oppositely arranged in the thickness direction of the first substrate, a plurality of supporting pieces are arranged between the first wall surface and the second wall surface, one end of each supporting piece is connected with or abutted against the first wall surface, and the other end of each supporting piece is connected with or abutted against the second wall surface.

The first substrate is hollow, and the support piece plays a role in supporting the first wall surface and the second wall surface between the first wall surface and the second wall surface, namely, the inner cavity of the first substrate is supported by the support piece, so that the possibility that the first substrate is flattened or bent is reduced, the service life of the first substrate is longer, and the possibility that the radiator fails due to local deformation is also reduced.

In an alternative embodiment, the radiator further includes a converging portion and a return pipe, the converging portion is disposed on one side of the first radiating portion away from the first substrate, a converging channel communicated with the second gas-liquid channel is disposed in the converging portion, the return pipe is disposed below the first radiating portion, one end of the return pipe is communicated with the first gas-liquid channel, and the other end of the return pipe is communicated with the converging channel.

When the cooling working medium is subjected to heat dissipation and condensation in the first heat dissipation part, the cooling working medium gradually changes into a liquid cooling working medium, one part of the liquid cooling working medium flows back to the first substrate from the first heat dissipation part, the other part of the liquid cooling working medium flows into a converging channel of the converging part, then enters a return pipe from the converging part, and then flows back to the first substrate through the return pipe. The first base plate, the first heat dissipation part, the converging part and the return pipe are mutually communicated, so that the possibility that liquid cooling working medium is stagnated in the first heat dissipation part is reduced.

In an alternative embodiment, a first evaporation zone is arranged in the first gas-liquid channel, the first evaporation zone is opposite to the first power device, one side of the first evaporation zone facing the first power device is connected with the inner wall surface of the first substrate, the first gas-liquid channel comprises a first chamber and a second chamber which are positioned on two sides of the first evaporation zone in the vertical direction, and the first evaporation zone is provided with a plurality of first runners which are communicated with the first chamber and the second chamber.

The first power device is propped against the area of the first substrate, where the first evaporation zone is arranged, heat on the first power device is transferred to the first evaporation zone through the first substrate, and as a plurality of first runners are arranged on the first evaporation zone, the contact area between the first evaporation zone and the cooling working medium is larger, namely the boiling nucleation point on the first evaporation zone is increased. The cooling working medium needs to flow between the first chamber and the second chamber through the first flow channel, namely, the cooling working medium flows into the upper part of the first evaporation zone from the lower part of the first evaporation zone through the first flow channel, and more boiling nucleation points are beneficial to changing the liquid cooling working medium into a gas state.

In an alternative embodiment, the two sides of the first evaporation zone are respectively provided with a second evaporation zone, the distribution directions of the two second evaporation zones are vertical to the vertical direction, the second evaporation zone is provided with a plurality of second flow channels communicated with the first chamber and the second chamber, and the number of the second flow channels on each second evaporation zone is smaller than that of the first flow channels.

The two second evaporation zones are respectively positioned at two sides of the first power device, a plurality of second flow channels are arranged on the second evaporation zones, so that boiling nucleation points on the second evaporation zones can be increased, and when the cooling working medium flows through the second flow channels, the cooling working medium is changed from a liquid state to a gas state. Because the second evaporation zone is far away from the first power device, and the first evaporation zone is near to the first power device, the number of second flow channels on each second evaporation zone is less than that of the first flow channels, and more cooling working medium can pass through the first evaporation zone.

Drawings

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

fig. 2 is a schematic diagram of an internal chamber of a power conversion apparatus according to an embodiment of the present application;

Fig. 3 is a schematic diagram of an internal structure of a heat dissipation cavity of a first power conversion device according to an embodiment of the present application;

FIG. 4 is a partial exploded view of a power conversion device according to an embodiment of the present application;

Fig. 5 is a schematic diagram of an internal structure of a radiator according to an embodiment of the present application;

FIG. 6 is an enlarged view at A in FIG. 4;

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

fig. 8 is a schematic structural diagram of a bus portion according to an embodiment of the present application;

Fig. 9 is a schematic structural view of another bus portion according to an embodiment of the present application;

FIG. 10 is a schematic view of a return pipe according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a first evaporation zone according to an embodiment of the present application;

Fig. 12 is a schematic structural view of another first evaporation zone according to an embodiment of the present application;

fig. 13 is a schematic structural view of a nut according to an embodiment of the present application;

fig. 14 is a schematic diagram of an internal structure of a heat dissipation cavity of a second power conversion device according to an embodiment of the present application;

Fig. 15 is a schematic view illustrating an internal structure of a heat dissipation cavity of a third power conversion device according to an embodiment of the present application;

Fig. 16 is a schematic diagram of an internal structure of a heat dissipation cavity of a fourth power conversion device according to an embodiment of the present application;

Fig. 17 is a partial exploded view of a fourth power conversion device according to an embodiment of the present application;

fig. 18 is a schematic structural diagram of another heat sink according to an embodiment of the present application;

fig. 19 is a schematic structural view of yet another heat sink according to an embodiment of the present application;

fig. 20 is a schematic structural diagram of a first connecting tube and a second connecting tube according to an embodiment of the present application.

Reference numerals:

a 100-power conversion device;

1-shell, 11-baffle plate, 111-power cavity, 112-heat dissipation cavity, 113-opening, 114-mounting port, 12-protective cover, 121-heat dissipation hole, 1211-air inlet hole and 1212-air outlet hole;

2-circuit board, 21-first power device, 211-bolt, 2111-head, 2112-rod, 22-through hole, 23-second power device, 24-inductor, 25-electronic device;

3-radiator, 31-first base plate, 310-first gas-liquid channel, 311-first wall, 312-second wall, 313-supporter, 314-first evaporation zone, 3141-first runner, 3142-convex strip, 315-second evaporation zone, 3151-second runner, 316-first chamber, 317-second chamber, 32-first heat sink, 320-second gas-liquid channel, 321-first condenser tube, 3211-microchannel, 33-accommodation space, 34-fin, 35-confluence part, 350-confluence channel, 351-second plate, 3511-concave structure, 352-confluence tube, 353-return tube, 36-second base plate, 360-third gas-liquid channel, 37-second heat sink, 370-fourth gas-liquid channel, 371-second condenser tube;

4-a first heat exchanger, 41-a first flat radiating pipe, 42-a first radiating fin, 43-a heat conducting plate and 44-radiating fins;

5-a second heat exchanger; 51-first flat radiating pipes, 22-first radiating fins;

6-first connecting pipe, 61-heat exchange inlet, 7-second connecting pipe, 71-heat exchange outlet and 8-fan.

Detailed Description

The following description of the technical solutions according to the embodiments of the present application will be given with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments.

In the present application, unless explicitly specified and limited otherwise, the orientation or positional relationship indicated by the terms "upper", "lower", etc. may include, but are not limited to, defined relative to the orientation in which the components are schematically disposed in the drawings, wherein these directional terms may be relative concepts, which are used in relation to the description and clarity, may be varied accordingly to the orientation in which the components are disposed in the drawings, and are not to be construed as limiting the application.

In the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated for distinguishing one element from another. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature.

In the present application, unless explicitly specified and limited otherwise, the meaning of "a plurality of" means two or more.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, or indirectly connected through an intermediary, or may be in communication with the interior of two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art. In addition, when describing a pipeline or channel, the terms "connected" and "connected" as used herein have the meaning of conducting. The specific meaning is to be understood in conjunction with the context.

Furthermore, in the present application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In the drawings of the embodiment of the application, physical structures such as parts, components and the like are represented by guide wires, and hollowed structures such as openings, holes, spaces, cavities and the like are represented by guide wires with arrows.

The embodiment of the present application provides a power conversion apparatus 100, for example, the power conversion apparatus 100 may be an inverter (e.g., a photovoltaic inverter), and the present application is not particularly limited in use and function of the power conversion apparatus 100. Fig. 1 schematically illustrates an external structure of the power conversion apparatus 100, and fig. 2 schematically illustrates an internal chamber of the power conversion apparatus 100.

Referring to fig. 1 and 2, the power conversion apparatus 100 includes a housing 1, and the housing 1 may be a cabinet-like structure (e.g., a cabinet), a box-like structure (e.g., a cabinet), etc., and the shape of the housing 1 is not particularly limited by the present application. The housing 1 comprises a partition 11, for example, the partition 11 may be a side wall (alternatively referred to as a side plate, a shell plate) of one side of the housing 1, that is, the partition 11 is a part of the housing 1. A sealed power chamber 111 is formed inside the housing 1, a heat dissipation chamber 112 is formed outside the housing 1, which is open to ventilation, and the partition 11 is located between the power chamber 111 and the heat dissipation chamber 112, that is, the power chamber 111 is an internal chamber of the housing 1, and the heat dissipation chamber 112 is located outside the housing 1.

The heat dissipation chamber 112 may be formed by arranging the protection cover 12 outside the casing 1, for example, referring to fig. 1 and 2, the power conversion apparatus further includes the protection cover 12, the heat dissipation chamber 112 is formed in the protection cover 12, the power chamber 111 and the heat dissipation chamber 112 are distributed along a first direction, the first direction is perpendicular to a vertical direction, and the protection cover 12 is provided with heat dissipation holes 121 communicating with the internal heat dissipation chamber 112. In some examples, the shield 12 may be a hollowed-out structure, and the heat dissipation holes 121 may be holes on the hollowed-out shield 12. In the examples of fig. 1 and 2, the heat dissipation holes 121 are provided in a partial region of the shield 12, and in other examples, the heat dissipation holes 121 may be provided in all regions of each wall of the shield 12, which is not particularly limited in the present application.

Referring to fig. 2, the power conversion apparatus 100 further includes a circuit board 2, for example, a printed circuit board (Printed Circuit Board, PCB). The circuit board 2 is disposed within the power chamber 111, and the circuit board 2 may be disposed in parallel with the partition 11. The circuit board 2 is provided with a plurality of devices, and in order to protect the circuit board 2 and the devices thereon, the protection level of the power cavity 111 is higher than that of the heat dissipation cavity 112, for example, IP (Ingress Protection) of the power cavity 111 is higher than that of the heat dissipation cavity 112.

The devices disposed on the circuit board 2 may be at least one of a chip, a resistor, a capacitor, a diode, and a triode, where a plurality of devices may be disposed on the same side of the circuit board 2, and a part of the plurality of devices may also be disposed on the side of the circuit board 2 facing away from the partition 11, for example, a plurality of electronic devices 25 (including but not limited to a capacitor, an inductor, a relay, etc.) are disposed on the side of the circuit board 2 facing away from the partition 11, and another part of the plurality of devices is disposed on the side of the circuit board 2 facing toward the partition 11.

In the present application, a plurality of devices are disposed on the board surfaces on both sides of the circuit board 2, and fig. 3 schematically illustrates an internal structure of the power conversion apparatus 100, and fig. 4 schematically illustrates an exploded view of a partial structure of the power conversion apparatus 100. Referring to fig. 3 and 4, the partition 11 is provided with an opening 113, the opening 113 communicates with the power chamber 111 and the heat dissipation chamber 112, and the opening 113 may be a square opening or a circular opening, which is not limited in the present application.

The circuit board 2 is provided with a first power device 21 on a side facing the opening 113, wherein the first power device 21 may constitute a power conversion circuit of the power conversion apparatus 100 to power-convert direct current inputted by the power conversion apparatus 100, and the first power device 21 may be a chip, for example. In some examples, the first power device 21 may be a device on the circuit board 2 that generates more heat. One end of the first power device 21 connected with the circuit board 2 is located in the power cavity 111, and one end of the first power device 21, which is away from the circuit board 2, extends into the heat dissipation cavity 112.

Referring to fig. 3 and 4, the power conversion apparatus 100 further includes a heat sink 3, the heat sink 3 being disposed in the heat dissipation chamber 112, the heat sink 3 including a first substrate 31 and a first heat dissipation portion 32, the first substrate 31 protruding toward a lower side of the first heat dissipation portion 32, the first substrate 31 being disposed at the opening 113, the first power device 21 being in contact with the first substrate 31 in the heat dissipation chamber 112, the first heat dissipation portion 32 being disposed on a side of the first substrate 31 facing away from the partition 11.

Fig. 5 exemplarily shows the structure inside the radiator 3, a first gas-liquid channel 310 is disposed in the first substrate 31, a second gas-liquid channel 320 communicating with the first gas-liquid channel 310 is disposed in the first heat dissipation portion 32, and a cooling medium for gas-liquid conversion is disposed in the inner chamber of the first substrate 31. The cooling medium may be water, or may be other refrigerant capable of performing gas-liquid conversion, and the application is not limited thereto.

When the first power device 21 heats, the heat on the first power device 21 is transferred to the first substrate 31, and heats the cooling medium in the first substrate 31, after the liquid cooling medium is heated, at least part of the cooling medium is changed into a gaseous state, the gaseous cooling medium flows into the first heat dissipation portion 32, that is, enters the second gas-liquid channel 320 from the first gas-liquid channel 310, and the heat dissipation holes 121 (auxiliary refer to fig. 2) on the housing 1 and communicated with the heat dissipation cavity 112 facilitate the heat exchange between the cooling medium in the first heat dissipation portion 32 and the outside, so that the gaseous cooling medium dissipates heat and condenses in the first heat dissipation portion 32, gradually changes into a liquid state, and then flows back into the first gas-liquid channel 310 of the first substrate 31 from the second gas-liquid channel 320, and thus circulates to continuously dissipate the heat of the first power device 21. By targeted heat dissipation of the first power device 21, the power conversion apparatus 100 can be operated stably.

For effective heat dissipation, the heat dissipation chamber 112 communicates with the outside through the heat dissipation hole 121, and the partition 11 may reduce the possibility that impurities of the heat dissipation chamber 112 or the outside enter the power chamber 111. In addition, the first substrate 31 is disposed at the opening 113, so that the first substrate 31 can play a role of shielding the opening 113 even if the first substrate 31 is in contact with the first power device 21, so that the possibility of mutual interference between the heat dissipation cavity 112 and the power cavity 111 is further reduced, the circuit board 2 can be disposed in the power cavity 111 with relatively strong protection capability, the heat dissipation of the first power device 21 is ensured, the safety of other devices (for example, a plurality of electronic devices 25) is ensured, and the possibility of failure of the power conversion device 100 is reduced.

Referring to fig. 3 and 4, in one example, an edge portion of the first substrate 31 faces the plate surface of the partition 11, and the first substrate 31 blocks the opening 113. In other examples, the side portions of the first substrate 31 face the plate surface of the partition 11, and the first substrate 31 closes off part of the openings 113. It should be noted that, the part of the plate surface on the first substrate 31 is opposite to the plate surface of the partition 11, that is, there is an overlap between the first substrate 31 and the partition 11, and in the case of the overlap, the first substrate 31 may be abutted against the partition 11, even if there is no overlap between the first substrate 31 and the partition 11, the opening 113 may be better shielded, so that the possibility that the gas in the heat dissipation cavity 112 enters the power cavity 111 through the opening 113 is reduced, that is, the possibility that the operation of the circuit board 2 and the devices thereon is affected by the external impurities is reduced, so that the power cavity 111 and the heat dissipation cavity 112 are independent from each other, and a high protection cavity (power cavity 111) is formed in the power conversion device 100 to place the circuit board 2, which is beneficial to the normal operation of the power conversion device 100.

For better heat dissipation, the first power device 21 is at least partially located below the first heat dissipation portion 32, in the example shown in fig. 5, a portion of the first power device 21 extends below the first heat dissipation portion 32, another portion of the first power device is opposite to the first heat dissipation portion 32, and an overlapping area of the first heat dissipation portion 32 and the first power device 21 is smaller, so that more area of the first heat dissipation portion 32 exchanges heat with air in the heat dissipation cavity 112, which is beneficial to improving the heat dissipation effect of the radiator 3.

In other examples, the first power device 21 is located entirely under the first heat dissipating part 32, that is, the first power device 21 and the first heat dissipating part 32 are located at both sides of the first substrate 31, respectively, and the first power device 21 and the first heat dissipating part 32 have a pitch in the vertical direction, or, the first power device 21 and the first heat dissipating part 32 do not overlap in the first direction.

Regarding the structure of the first substrate 31, in one example provided by the present application, referring to fig. 4 and 5, the first substrate 31 may be a square plate-like structure. In other examples, the first substrate 31 may also be a disk-shaped or other shaped plate without obvious shape, which is not limited by the present application.

The first heat dissipation part 32 may be any structure capable of performing a condensation function, for example, the first heat dissipation part 32 may be a microchannel condenser provided with heat dissipation fins, fig. 6 is an enlarged view of a portion a in fig. 4, referring to fig. 5 and 6, the first heat dissipation part 32 includes a plurality of first condensation pipes 321 arranged at intervals along a second direction, the first direction, the second direction and the vertical direction are perpendicular to each other, in the example shown in fig. 5, each first condensation pipe 321 may be a flat microchannel pipe, a plurality of microchannels 3211 in each first condensation pipe 321 are arranged along the vertical direction, and each microchannel 3211 extends along the first direction.

It should be noted that, the micro-channel 3211 may be any channel capable of flowing a cooling medium, and the size and structure of the micro-channel 3211 are not limited by the present application. The micro channels 3211 in each first condensation duct 321 form an inner chamber of the first condensation duct 321, and the inner chambers of the first condensation ducts 321 form the second gas-liquid channels 320 of the first heat dissipation part 32. In other examples, the first condensing duct 321 may be not a plate-shaped duct in which a plurality of layers of channels are provided, but a plate-shaped duct in which a complete chamber is provided, or a tube provided in a zigzag manner, which is not limited by the present application.

In one example, referring to fig. 6, a plurality of fins 34 are provided between two adjacent first condensing ducts 321, and in other examples, the fins 34 may not be provided.

After the cooling medium in the first heat dissipating portion 32 is changed to a liquid state, the cooling medium needs to flow back into the first substrate 31, and in order to facilitate the cooling medium in the first heat dissipating portion 32 to flow back into the first substrate 31, in some examples, referring to fig. 7, fig. 7 illustrates another structure of the first heat dissipating portion 32, and the first heat dissipating portion 32 may be disposed obliquely. For example, the included angle a between the first gas-liquid channel 310 and the second gas-liquid channel 320 is greater than 90 degrees and less than 180 degrees, wherein the included angle a may be 95 degrees, 120 degrees, 150 degrees, 170 degrees, etc. For another example, the included angle a between the first gas-liquid channel 310 and the second gas-liquid channel 320 is greater than 90 degrees and less than or equal to 160 degrees, where the included angle a may be 110 degrees, 130 degrees, 140 degrees, 160 degrees, etc.

When the first heat dissipation portion 32 is required to be disposed obliquely, in an example in which the first heat dissipation portion 32 includes a plurality of first condensation pipes 321 (for example, a flat pipe structure of micro-channels), the first condensation pipes 321 may be flat pipes similar to a parallelogram structure, and each micro-channel 3211 is inclined obliquely upward from the first substrate 31 in the first direction so that the liquid in the first heat dissipation portion 32 flows back to the first substrate 31, reducing the possibility of stagnation of the liquid cooling medium in the first heat dissipation portion 32.

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

In addition, in order to facilitate the cooling medium backflow, the radiator 3 may further include a converging portion 35, fig. 5 and 7 respectively show positions of the converging portion 35 in two examples, the converging portion 35 is disposed on a side of the first heat dissipation portion 32 facing away from the first substrate 31, a converging channel 350 is disposed in the converging portion 35, and the converging channel 350 of the converging portion 35 communicates with the second gas-liquid channel 320 of the first heat dissipation portion 32. When the cooling medium is cooled and condensed in the first heat dissipation portion 32, the cooling medium gradually changes back into a liquid cooling medium, a part of the liquid cooling medium directly flows back to the first substrate 31 from the first heat dissipation portion 32 without entering the converging portion 35, and another part of the liquid cooling medium flows into the converging channel 350 of the converging portion 35, then flows downwards from the converging channel 350, and flows back to the first substrate 31 through the bottom of the second gas-liquid channel 320.

Fig. 8 exemplarily shows a structure of the bus bar 35, referring to fig. 8, the bus bar 35 may be formed by edge-connecting two plates (a first plate and a second plate 351) and internally bulging to enclose the bus bar channel 350, wherein the first plate (blocked by the second plate 351 in the drawing, located at the rear of the second plate 351) is connected with the first heat sink 32, the second plate 351 is located at one side of the first plate facing away from the first heat sink 32, and a plurality of concave structures 3511 may be provided on the second plate 351, and the concave structures 3511 are recessed into the bus bar channel 350 toward the first plate (auxiliary referring to fig. 7) and abut against the first plate to play a supporting role, thereby reducing the possibility of the internal chamber of the bus bar 35 being collapsed.

Fig. 9 exemplarily shows a structure of another junction 35, and in the example shown in fig. 9, the first heat sink 32 includes a plurality of first condensing ducts 321, the junction 35 includes a plurality of junction pipes 352, each junction pipe 352 communicates with one first condensing duct 321, and the inner spaces of all the junction pipes 352 constitute a junction channel 350. In other examples, each manifold 352 is a solid tube.

Fig. 10 exemplarily shows a structure of a further junction 35, and referring to fig. 10, the junction 35 is constructed as a hollow plate or a hollow box-like structure, in which case a support structure may also be provided in the junction channel 350 of the junction 35, which support structure functions as the concave structure 3511 of fig. 8. The support structure is different from the concave structure 3511 in fig. 8 in that the concave structure 3511 in fig. 8 is formed directly on the second plate 351 by locally pressing or by other processing methods during processing, and the support structure illustrated in fig. 10 may be additionally disposed (e.g., post-welding), or the support structure may not be disposed in the example illustrated in fig. 10.

In some examples, the radiator 3 further includes a return pipe 353, taking the confluence part 35 shown in fig. 10 as an example, the return pipe 353 is disposed below the first heat dissipation part 32, one end of the return pipe 353 communicates with the first gas-liquid channel 310 in the first substrate 31, the other end communicates with the confluence channel 350 in the confluence part 35, and the positions of the first gas-liquid channel 310 and the confluence channel 350 may refer to fig. 5 or 7. Wherein the return tube 353 may be provided in plurality and spaced apart in the second direction.

In the above example, after the cooling medium is cooled and condensed in the first heat dissipating part 32, the cooling medium gradually changes back to the liquid cooling medium, a part of the liquid cooling medium flows back to the first substrate 31 from the second gas-liquid channel 320 of the first heat dissipating part 32, and another part of the liquid cooling medium flows into the converging part 35, then flows into the return pipe 353 from the converging channel 350, and flows back to the first substrate 31 through the return pipe 353. The first substrate 31, the first heat radiation portion 32, the confluence portion 35, and the return pipe 353 communicate with each other, reducing the possibility that the liquid cooling medium stagnates in the first heat radiation portion 32.

In addition, in order to facilitate evaporation, the structure of the first substrate 31 may be modified, for example, fig. 11 exemplarily shows another structure of the first substrate 31, and referring to fig. 11, a first evaporation zone 314 is disposed in the first gas-liquid channel 310 of the first substrate 31, the first evaporation zone 314 is disposed opposite to the first power device 21 (the position of the first power device 21 may refer to fig. 5 or fig. 7), and a side of the first evaporation zone 314 facing the first power device 21 is connected to an inner wall surface of the first substrate 31, that is, a region where the first evaporation zone 314 is disposed in the first substrate 31 is a region where the first substrate 31 contacts the first power device 21.

The first gas-liquid channel 310 inside the first substrate 31 includes a first chamber 316 and a second chamber 317 located at both sides of the first evaporation zone 314 in the vertical direction, and the first evaporation zone 314 is provided with a plurality of first flow channels 3141 communicating the first chamber 316 and the second chamber 317, and it is understood that the first flow channels 3141 also belong to the first gas-liquid channel 310. In the example shown in fig. 11, the first flow channels 3141 may be grooves opened on the first evaporation zone 314, each groove extending in a vertical direction such that each first flow channel 3141 extends in a vertical direction, thereby communicating the first chamber 316 and the second chamber 317 distributed in the vertical direction, and the plurality of first flow channels 3141 are spaced apart in the second direction.

Since the first power device 21 is abutted against the region of the first substrate 31 where the first evaporation zone 314 is provided, heat on the first power device 21 is transferred to the first evaporation zone 314 through the first substrate 31. The first evaporation zone 314 is provided with the plurality of first flow channels 3141, which can increase the surface area of the first evaporation zone 314, so that the contact area between the first evaporation zone 314 and the cooling medium is larger, that is, the boiling nucleation point on the first evaporation zone 314 is increased. The cooling medium needs to flow between the first chamber 316 and the second chamber 317 through the first flow channel 3141, that is, the cooling medium flows from below the first evaporation zone 314 through the first flow channel 3141 into above the first evaporation zone 314, and more boiling nucleation sites are beneficial for the liquid cooling medium to change into a gas state.

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

In other examples, referring to fig. 12, fig. 12 illustrates another structure of a first evaporation zone 314, where the first evaporation zone 314 includes a plurality of ribs 3142 arranged in a matrix, and a channel formed by the plurality of ribs 3142 arranged in a matrix and capable of communicating with the first chamber 316 and the second chamber 317 is a first flow channel 3141.

In some examples, referring to fig. 11 and 12, the second evaporation zone 315 is provided at both sides of the first evaporation zone 314, and a distribution direction (second direction) of the two second evaporation zones 315 is perpendicular to the vertical direction. The second evaporation zone 315 is provided with a plurality of second flow channels 3151 communicating the first chamber 316 and the second chamber 317, it being understood that the second flow channels 3151 also belong to the first gas-liquid channel 310. The provision of the second flow path 3151 increases the surface area of the second evaporation zone 315, and increases the boiling nucleation sites thereon, facilitating the change of the cooling medium from a liquid state to a gaseous state as it passes through the second flow path 3151.

The second evaporation zones 315 are far from the first power devices 21, and the first evaporation zones 314 are near to the first power devices 21, so that the number of second flow channels 3151 on each second evaporation zone 315 is smaller than that of first flow channels 3141, and more cooling working medium passes through the first evaporation zones 314, thereby being beneficial to the cooling working medium to absorb the heat of the first power devices 21.

Since the first gas-liquid passage 310 is provided in the first substrate 31, in order to reduce the possibility of deformation of the first substrate 31, in some examples, referring to fig. 11 and 12, an inner wall surface of the first substrate 31 surrounding the first gas-liquid passage 310 includes a first wall surface 311 and a second wall surface 312, wherein fig. 11 and 12 only exemplarily show the first wall surface 311 (a wall surface close to the first power device 21), the second wall surface 312 may assist in referring to fig. 5, the first wall surface 311 and the second wall surface 312 are disposed opposite to each other in a thickness direction (first direction) of the first substrate 31, a plurality of supporters 313 are provided between the first wall surface 311 and the second wall surface 312, and one end of each supporter 313 is connected to or abutted against the first wall surface 311, and the other end is connected to or abutted against the second wall surface 312. For example, both ends of each support 313 are connected to the first wall 311 and the second wall 312, respectively.

The supporting member 313 may be a protrusion (bump), or may be other protruding supporting structures, where the supporting member 313 serves to support the first wall 311 and the second wall 312 between the first wall 311 and the second wall 312, that is, the internal chamber (the first gas-liquid channel 310) of the first substrate 31 is supported by the supporting member 313, so that the possibility that the first substrate 31 is flattened or bent is reduced, the service life of the first substrate 31 is longer, and the possibility that the radiator 3 fails due to local deformation is reduced.

In both examples shown in fig. 11 and 12, the space of the first chamber 316 is large, and a plurality of supporters 313 may be disposed within the first chamber 316. In other examples, for example, in an example in which the first and second evaporation bands 314 and 315 are not provided, the support 313 may be provided at any suitable position to function as a support for the first substrate 31.

In the example where the first evaporation zone 314 and the second evaporation zone 315 are provided, both sides of the first evaporation zone 314 in the first direction may be connected to the first wall surface 311 and the second wall surface 312, respectively, and both sides of the second evaporation zone 315 in the first direction may be connected to the first wall surface 311 and the second wall surface 312, respectively.

In order to better transfer heat on the first power device 21 to the first substrate 31, the first power device 21 may be fixedly connected to the first substrate 31, so that the first power device 21 is fully contacted with the first substrate 31, and a possibility of a gap occurring between contact surfaces of the first power device 21 and the first substrate 31 is reduced, for example, fig. 13 illustrates an exemplary manner of fixing connection.

Referring to fig. 13, the first power device 21 may be fixedly connected to the first substrate 31 by a bolt 211, a through hole 22 is provided in the circuit board 2, the through hole 22 is used for allowing a head portion 2111 of the bolt 211 to pass through, a rod portion 2112 of the bolt 211 passes through the first power device 21 and is in threaded connection with the first substrate 31, and the head portion 2111 of the bolt 211 abuts against a surface of the first power device 21 facing away from the first substrate 31, so that the first power device 21 may be tightly attached to the first substrate 31, and thus, the heat dissipation effect of the first power device 21 is better. The bolts 211 may be provided in plural numbers, and the corresponding through holes 22 are also provided in plural numbers.

In the example shown in fig. 13, the shaft portion 2112 of the bolt 211 does not extend into or through the first gas-liquid passage 310. In addition, the head portion 2111 of the bolt 211 abuts against the first power device 21 instead of the circuit board 2, damage to the circuit board 2 when the bolt 211 is fixed is reduced, and influence on the circuit board 2 when the first power device 21 and the first substrate 31 are connected is reduced.

Since the circuit board 2 is disposed in the power cavity 111, the circuit board 2 and the devices thereon generate heat seriously when the power conversion apparatus 100 is operated, and the temperature in the power cavity 111 is high, heat dissipation from the power cavity 111, or heat dissipation from the circuit board 2 and the devices thereon (e.g., the electronic device 25 in the example of fig. 2) is required. Referring back to fig. 3 and 4, the power conversion apparatus 100 may further include a first heat exchanger 4, the first heat exchanger 4 for transferring heat within the power cavity 111 to the heat dissipation cavity 112 to dissipate heat from the electronic device 25.

In one example, the first heat exchanger 4 is disposed within the heat dissipation chamber 112, and the heat exchange channels within the first heat exchanger 4 are in communication with the power chamber 111. The first heat exchanger 4 has a first heat exchanging channel (located in the first heat exchanger 4 and therefore not shown in the drawings) formed therein, the first heat exchanging channel being isolated from the heat dissipating chamber 112, the first heat exchanging channel having an inlet and an outlet (blocked and therefore not shown in the drawings) provided on the first heat exchanger 4, the inlet and the outlet of the first heat exchanging channel both communicating with the power chamber 111. For example, the inlet of the first heat exchange channel and the outlet of the first heat exchange channel are respectively communicated with corresponding mounting ports 114 on the partition 11, so as to realize the communication between the first heat exchange channel and the power cavity 111 inside the first heat exchanger 4.

The first heat exchanger 4 is arranged to enable hot air in the power cavity 111 to enter the first heat exchange channel of the first heat exchanger 4, then heat exchange is carried out between the hot air and air in the heat dissipation cavity 112 in the first heat exchanger 4, and the heat dissipation device 3 is communicated with the outside through the heat dissipation holes 121 to enable the air in the heat dissipation cavity 112 to exchange heat with the outside. In this way, the first heat exchanger 4 can efficiently dissipate heat in the heat dissipation cavity 112, so that the temperature in the power cavity 111 is reduced, and the power conversion device 100 can stably operate.

Referring to fig. 4, the first heat exchanger 4 may be a fin heat exchanger, for example, the first heat exchanger 4 includes a plurality of first flat heat dissipating tubes 41 and a plurality of first heat dissipating fins 42 (for example, a fin-like structure), the plurality of first flat heat dissipating tubes 41 are spaced apart along a first direction, the plurality of first heat dissipating fins 42 are disposed between two adjacent first flat heat dissipating tubes 41, and an inner space of the plurality of first flat heat dissipating tubes 41 forms a first heat exchanging channel of the first heat exchanger 4. In other examples, the first heat exchange channel within the first heat exchanger 4 may be an "S" like or serpentine like channel.

Referring to fig. 3 and 4, the first heat exchanger 4 is at least partially located between a portion of the first substrate 31 protruding from the first heat dissipation portion 32 and the first heat dissipation portion 32, or, an accommodating space 33 is defined between a portion of the first substrate 31 protruding below the first heat dissipation portion 32 and the first heat dissipation portion 32, and the first heat exchanger 4 is at least partially disposed in the accommodating space 33. For example, the first heat exchanger 4 is located on a side of the first substrate 31 facing away from the partition plate 11, and the first heat exchanger 4 is located below the first heat radiation portion 32. The first heat exchanger 4 is arranged in the accommodating space 33, so that the radiator 3 and the first heat exchanger 4 can be arranged more compactly, and the space occupation of the radiating cavity 112 is reduced.

In other examples, referring to fig. 14, fig. 14 illustrates another placement of the first heat exchanger 4, where the first heat exchanger 4 is located within the power cavity 111, and a first heat exchange channel within the first heat exchanger 4 is isolated from the power cavity 111, the first heat exchange channel having an inlet and an outlet disposed on the first heat exchanger 4, the inlet and the outlet of the first heat exchange channel being in communication with the heat dissipation cavity 112 through corresponding mounting openings 114 in the partition 11, respectively.

Through the design manner, the air in the heat dissipation cavity 112 can enter the first heat exchange channel of the first heat exchanger 4 and then exchange heat with the hot air in the power cavity 111 through the first heat exchanger 4, and the heat dissipation cavity 112 is open for ventilation. In this way, ambient air may continuously enter the first heat exchange path of the first heat exchanger 4, reducing the temperature in the power chamber 111, so that the power conversion apparatus 100 may stably operate.

In other examples, referring to fig. 15, fig. 15 illustrates still another placement of the first heat exchanger 4, where the first heat exchanger 4 is located in the heat dissipation cavity 112, the first heat exchanger 4 includes a heat conducting plate 43 and a plurality of heat dissipation fins 44 that are connected to each other, the heat conducting plate 43 is thermally bonded to the first substrate 31, the plurality of heat dissipation fins 44 are fixed on a side of the heat conducting plate 43 facing away from the first substrate 31 along the second direction, and a fan 8 is disposed in the heat dissipation cavity 112, and the fan 8 is configured to generate an air flow through the heat dissipation fins 44.

The temperature of the electronic device 25 increases, so that the temperature of the power cavity 111 increases, and heat in the power cavity 111 is transferred to the heat conducting plate 43 through the first substrate 31, and the heat conducting plate 43 transfers the heat to the heat dissipation fins 44. The fan 8 blows air towards the heat dissipation fins 44, and the heat dissipation cavity 112 is opened for ventilation, so that heat on the heat dissipation fins 44 can be blown out of the heat dissipation cavity 112 (or out of the protective cover 12) through the air, namely, the heat dissipation fins 44 can dissipate heat, namely, indirectly, the heat dissipation of the electronic device 25 in the power cavity 111 can be realized by rotating the fan 8.

In an example where the first substrate 31 protrudes below the first heat dissipating portion 32, referring to fig. 15, the heat conductive plate 43 is thermally bonded to a portion of the first substrate 31 protruding above the first heat dissipating portion 32, and the heat dissipating fins 44 are located below the first heat dissipating portion 32. The first base plate 31 extends downward and forms a space (may be the accommodating space 33 in fig. 4) with the first heat dissipating part 32, and the first heat exchanger 4 is installed in the space, so that the heat sink 3 and the first heat exchanger 4 can be installed more compactly, and the space occupation of the heat dissipating cavity 112 is reduced. In addition, the first power device 21 contacts with the protruding portion of the first substrate 31 (see fig. 5), and the heat conducting plate 43 contacts with the protruding portion of the first substrate 31, and may assist in dissipating heat from the first power device 21 in cooperation with the heat dissipating fins 44.

In some examples, referring to fig. 15, the power device further includes a device with more serious heat generation such as an inductor 24 (different from the inductor in the plurality of electronic devices 25), where the device with more serious heat generation such as the inductor 24 may be disposed in the heat dissipation cavity 112 and fixedly connected with the partition 11, so as to facilitate heat dissipation of the device, and the device with more serious heat generation such as the inductor 24 may be electrically connected with the circuit board 2 through a wire, and the wire passes through the partition 11. In order to reasonably utilize the space in the heat dissipation cavity 112, the inductor 24 may be located above the first substrate 31.

In addition, in order to facilitate heat dissipation, in an example, returning to fig. 1 and 2, the power conversion apparatus 100 further includes a fan 8, the heat dissipation hole 121 includes an air inlet 1211 and an air outlet 1212, one of the air inlet 1211 and the air outlet 1212 is located below the heat sink 3, and the other is located above the heat sink 3, that is, the air inlet 1211 and the air outlet 1212 are located at the upper and lower sides of the heat sink 3, respectively, the fan 8 is used for driving air entering through the air inlet 1211 to be discharged from the air outlet 1212, and under the action of the fan 8, the air outside the protection cover 12 enters from the air inlet 1211 and is discharged from the air outlet 1212 after passing through the heat sink 3, so that the external air can sufficiently pass through the heat sink 3, thereby improving the heat dissipation effect of the heat sink 3.

For example, the air inlet 1211 is provided below the radiator 3, and the air outlet 1212 is provided above the radiator 3. The temperature of the air in the heat dissipation cavity 112 after heat exchange with the heat exchanger and the radiator 3 is higher, the density of the hot air is smaller than that of the cold air, and the hot air with the same volume is lighter than that of the cold air, so that the hot air rises. Therefore, the air inlet 1211 is arranged below and the air outlet 1212 is arranged above, so as to conform to the flow rule of the air in the heat dissipation cavity 112, and make the heat dissipation effect in the heat dissipation cavity 112 better.

Wherein, the air inlet 1211 and the air outlet 1212 may be provided in plurality, and in some examples, the air inlet 1211 and the air outlet 1212 are the same in shape and size.

Fig. 16 exemplarily shows an internal structure of another power conversion apparatus 100, fig. 17 exemplarily shows an exploded view of a part of the structure of the power conversion apparatus 100 in fig. 16, and a structure of the case 1 and a structure of the shield 12 of this example may be identical to those of the case 1 and the shield 12 shown in fig. 1. In the example shown in fig. 16 and 17, the heat sink 3 includes, in addition to the first substrate 31 and the first heat dissipating portion 32, a second substrate 36 and a second heat dissipating portion 37, the second substrate 36 being distributed and fixedly connected to the first substrate 31 in the vertical direction.

Fig. 18 exemplarily shows the internal chambers of the second substrate 36 and the second heat dissipating part 37, referring to fig. 17 and 18, a third gas-liquid channel 360 is disposed in the second substrate 36, a cooling medium for gas-liquid conversion is disposed in the third gas-liquid channel 360 of the second substrate 36, a fourth gas-liquid channel 370 communicating with the third gas-liquid channel 360 is disposed in the second heat dissipating part 37, and the third gas-liquid channel 360 is isolated from the first gas-liquid channel 310, that is, the second substrate 36 and the first substrate 31 are not communicated with each other. And, the second heat sink 37 is provided on a side of the second substrate 36 facing away from the partition 11.

Referring to fig. 17, the side of the circuit board 2 facing the opening 113 is provided with a second power device 23 in addition to the first power device 21, and in some examples, the second power device 23 may also constitute a power conversion circuit of the power conversion apparatus 100 to perform power conversion on the direct current input by the power conversion apparatus 100, and for example, the second power device 23 may be a chip. In other examples, the second power device 23 may also be a power device on the circuit board 2 that functions otherwise. When the second power device 23 contacts the second substrate 36, and there are more power devices that need to dissipate heat on the circuit board 2 and there is a height difference between different power devices (the first power device 21 and the second power device 23), the second substrate 36 and the second heat dissipation portion 37 can better dissipate heat for the second power device 23, so that the possibility that the normal operation of the power conversion device 100 is affected due to serious heat generated by the second power device 23 is reduced.

After the first substrate 31 and the second substrate 36 are connected, the opening 113 is blocked, so that the possibility that air in the heat dissipation cavity 112 enters the power cavity 111 is reduced. In addition, the power chamber 111 (e.g., the inside of the case 1 in fig. 16) and the heat dissipation chamber 112 are distributed in the first direction, and the first substrate 31 and the second substrate 36 are distributed in the vertical direction, the size of the heat sink 3 in the first direction can be reduced, that is, the size of the heat dissipation chamber 112 in the first direction can be reduced, so that the size of the power conversion device 100 in the first direction can be reduced.

Referring to fig. 18, the second substrate 36 protrudes below the second heat dissipation portion 37, and the second power device 23 is partially located below the second heat dissipation portion 37, so that an overlapping area between the second heat dissipation portion 37 and the second power device 23 is reduced, so that more area of the second heat dissipation portion 37 exchanges heat with air in the heat dissipation cavity 112, which is beneficial to improving heat dissipation effect. In other examples, the second power device 23 is located entirely below the second heat sink 37, that is, the second power device 23 and the second heat sink 37 are located at two sides of the second substrate 36, respectively, and the second power device 23 and the second heat sink 37 have a pitch in the vertical direction.

In some examples, referring to fig. 18, the second substrate 36 may have the same structure as the first substrate 31. In other examples, the second substrate 36 may be other structures that can function in the same manner as the first substrate 31. The dimensions of the first substrate 31 and the second substrate 36 may be the same or different, and the present application is not particularly limited thereto. In the example shown in fig. 16 to 18, the first substrate 31 is located above the second substrate 36, and in this example, the first heat dissipating portion 32 is also located above the second heat dissipating portion 37. In other examples, the first substrate 31 may also be located below the second substrate 36, and in such examples, the first heat dissipating portion 32 is located below the second heat dissipating portion 37.

Referring to fig. 17, the second heat dissipation part 37 may include a plurality of second condensation pipes 371 disposed at intervals, and a plurality of fins 34 (similar to the structure of the first heat dissipation part 32 in fig. 6) are disposed between two adjacent second condensation pipes 371, and the number of fins 34 disposed at a nearer one of the first heat dissipation part 32 and the second heat dissipation part 37 than at a farther one of the air intake holes 1211 is smaller than the number of fins 34 disposed at a farther one of the air intake holes 1211.

Since the wind at the air inlet 1211 just enters the heat dissipation chamber 112 from the outside, the wind temperature is lower nearer to the air inlet 1211, when the wind passes through one of the first heat dissipation portion 32 and the second heat dissipation portion 37 nearer to the air inlet 1211, heat exchange is performed, the temperature of the wind after heat exchange is increased, that is, the wind temperature is higher nearer to the air outlet 1212 in the heat dissipation chamber 112, the thinner fins 34 are arranged on the one of the first heat dissipation portion 32 and the second heat dissipation portion 37 nearer to the air inlet 1211, so that a large amount of wind passes through, more wind blows to the one farther to strengthen the heat dissipation capability, and the denser secondary fins 34 are arranged on the one farther to the air inlet 1211, so that the vertically arranged first heat dissipation portion 32 and the second heat dissipation portion 37 can dissipate heat uniformly.

Referring to fig. 16 and 17, taking an example that the air inlet 1211 is located below the radiator 3, if the first heat dissipating portion 32 is located above the second heat dissipating portion 37, the fins 34 of the second heat dissipating portion 37 are more sparse than the first heat dissipating portion 32, that is, the fins 34 of the first heat dissipating portion 32 are denser than the second heat dissipating portion 37. In the example where the air inlet 1211 is located above the radiator 3, if the first heat dissipating portion 32 is located above the second heat dissipating portion 37, the fins 34 of the second heat dissipating portion 37 are denser than the first heat dissipating portion 32, that is, the fins 34 of the first heat dissipating portion 32 are more sparse than the second heat dissipating portion 37.

In other examples, referring to fig. 19, fig. 19 illustrates another arrangement of the first heat dissipating portion 32 and the second heat dissipating portion 37, in which the dimension of one of the first heat dissipating portion 32 and the second heat dissipating portion 37, which is closer to the air intake 1211, is smaller than the dimension of the other one, which is farther from the air intake 1211, in the first direction. That is, the heat dissipation portion near the air inlet 1211 is shorter in the first direction, and a different arrangement is adopted, so that more cold air can be blown to one of the first heat dissipation portion 32 and the second heat dissipation portion 37 farther from the air inlet 1211, thereby enhancing the heat dissipation capability of the heat sink 3, and enabling the vertically arranged first heat dissipation portion 32 and second heat dissipation portion 37 to dissipate heat uniformly.

In the example shown in fig. 19, the fins 34 may not be provided, or the fins 34 may be provided in the first heat dissipation portion 32 and the second heat dissipation portion 37, and the degree of the density of the fins 34 in the first heat dissipation portion 32 and the second heat dissipation portion 37 may be provided according to the distance from the air inlet 1211, which is not described here.

Referring back to fig. 16 and 17, the power conversion apparatus 100 includes, in addition to the first heat exchanger 4, a second heat exchanger 5 disposed in the heat dissipation chamber 112, the second heat exchanger 5 for transferring heat in the power chamber 111 to the heat dissipation chamber 112 to dissipate heat of the electronic device 25. For example, a second heat exchange channel (not shown in the drawings because it is located in the second heat exchanger 5) is disposed in the second heat exchanger 5, and the second heat exchange channel is in communication with the power chamber 111 (located in the housing 1), and the hot air in the power chamber 111 can exchange heat with the air in the heat dissipation chamber 112 through the first heat exchanger 4 and the second heat exchanger 5, so that the temperature in the power chamber 111 is further reduced, and the power conversion apparatus 100 can stably operate.

Referring to fig. 16, since the first substrate 31 protrudes downward from the first heat dissipating portion 32 and the second substrate 36 extends downward from the second heat dissipating portion 37, there is room below both the first heat dissipating portion 32 and the second heat dissipating portion 37, one of the first heat exchanger 4 and the second heat exchanger 5 is disposed between the first heat dissipating portion 32 and the second heat dissipating portion 37, and the other is located below the lower one of the first heat dissipating portion 32 and the second heat dissipating portion 37.

That is, when the first heat exchanger 4 and the second heat exchanger 5 are disposed, the surplus space below the first heat radiating portion 32 and the second heat radiating portion 37 is fully utilized, the installation of the heat radiator 3, the first heat exchanger 4 and the second heat exchanger 5 is made more compact, the space in the vertical direction of the heat radiating cavity 112 is fully utilized, and the size of the power conversion apparatus 100 in the first direction is reduced.

For example, in the example shown in fig. 16, the first heat radiating portion 32 is located above the second heat radiating portion 37, and then the accommodating space 33 is located between the first heat radiating portion 32 and the second heat radiating portion 37 (refer to fig. 17 as an auxiliary), the first heat exchanger 4 is disposed between the first heat radiating portion 32 and the second heat radiating portion 37, and the second heat exchanger 5 is disposed below the second heat radiating portion 37. In other examples, the first heat dissipating portion 32 is located below the second heat dissipating portion 37, and then the second heat exchanger 5 is disposed between the first heat dissipating portion 32 and the second heat dissipating portion 37, and the first heat exchanger 4 is disposed below the first heat dissipating portion 32.

In one example, to facilitate uniform installation of the first heat exchanger 4 and the second heat exchanger 5, the first heat exchanger 4 and the second heat exchanger 5 may be connected, and this structure is exemplarily shown in fig. 20, and referring to fig. 20, an inlet of the first heat exchange channel in the first heat exchanger 4 and an inlet of the second heat exchange channel in the second heat exchanger 5 are both communicated with the first connecting pipe 6, an outlet of the heat exchange channel in the first heat exchanger 4 and an outlet of the heat exchange channel in the second heat exchanger 5 are both communicated with the second connecting pipe 7, and the first connecting pipe 6 and the second connecting pipe 7 are both communicated with the power chamber 111.

The first heat exchanger 4 and the second heat exchanger 5 are mutually communicated and fixed through the first connecting pipe 6 and the second connecting pipe 7, so that the integration level of the first heat exchanger 4 and the second heat exchanger 5 is improved, the first heat exchanger 4 and the second heat exchanger 5 do not need to be respectively installed and respectively communicated with the power cavity 111, and unified disassembly and assembly of the first heat exchanger 4 and the second heat exchanger 5 in the heat dissipation cavity 112 are facilitated.

Wherein, the first connecting pipe 6 is provided with a heat exchange inlet 61, the second connecting pipe 7 is provided with a heat exchange outlet 71, and the heat exchange inlet 61 and the heat exchange outlet 71 are respectively communicated with corresponding mounting ports 114 (refer back to fig. 17) on the partition 11, so as to realize the communication between the internal heat exchange channel of the first heat exchanger 4 and the internal heat exchange channel of the second heat exchanger 5 and the power cavity 111. The hot air in the power cavity 111 enters the first heat exchanger 4 and the second heat exchanger 5 through the first connecting pipe 6 respectively, and after the hot air in the first heat exchanger 4 and the second heat exchanger 5 exchanges heat with the air in the heat dissipation cavity 112, the hot air enters the second connecting pipe 7 uniformly, and enters the power cavity 111 through the second connecting pipe 7.

In one example, referring to fig. 16, the first heat exchanging channel of the first heat exchanger 4 and the second heat exchanging channel of the second heat exchanger 5 each extend in the second direction, and the first connection pipe 6 and the second connection pipe 7 are respectively located at a lower one of the first heat radiating portion 32 and the second heat radiating portion 37, on different sides in the second direction. For example, in the example shown in fig. 16, the first heat dissipating portion 32 is located above the second heat dissipating portion 37, and the first connecting pipe 6 and the second connecting pipe 7 are located on different sides of the second heat dissipating portion 37 in the second direction.

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

In one example, referring to fig. 20, the second heat exchanger 5 may be a fin heat exchanger, for example, the second heat exchanger 5 includes a plurality of second flat radiating pipes 51 and a plurality of second radiating fins 52 (e.g., fin-like structure), the plurality of second flat radiating pipes 51 are spaced apart along the first direction, the plurality of second radiating fins 52 are disposed between each set of two adjacent second flat radiating pipes 51, and the inner spaces of the plurality of second flat radiating pipes 51 constitute the second heat exchanging channel of the second heat exchanger 5. In other examples, the second heat exchange channels within the second heat exchanger 5 may be "S" like channels or serpentine like channels.

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

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

In some examples, the first heat exchanger 4 may be separately provided from the first substrate 31 and respectively installed in the heat dissipation chamber 112. In other examples, the first heat exchanger 4 may be integrally connected with the first substrate 31.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A power conversion device, characterized in that it comprises a housing, a circuit board, a heat sink, and a first heat exchanger.

A sealed power cavity is formed inside the housing, and an open and ventilated heat dissipation cavity is formed outside the housing. The housing includes a partition between the power cavity and the heat dissipation cavity. The protection level of the power cavity is higher than that of the heat dissipation cavity. An opening is provided on the partition. A circuit board is disposed inside the power cavity. A first power device is mounted on the side of the circuit board facing the opening. The first power device constitutes the power conversion circuit of the power conversion device to perform power conversion on the DC power input to the power conversion device.

The heat sink is disposed within the heat dissipation cavity and includes a first substrate and a first heat dissipation portion. The first substrate is disposed at the opening and makes thermally conductive contact with the first power device within the heat dissipation cavity. The first heat dissipation portion extends outward from the first substrate, and the first substrate protrudes downward from the first heat dissipation portion. The first power device makes thermally conductive contact with the portion of the first substrate protruding downward from the first heat dissipation portion, and the first power device is at least partially located below the first heat dissipation portion. A first gas-liquid channel is disposed within the first substrate, and the first gas-liquid channel includes a plurality of first flow channels. The plurality of first flow channels are at least partially located in the portion of the first substrate protruding downward from the first heat dissipation portion, and the plurality of first flow channels are disposed opposite to the first power device. A second gas-liquid channel is disposed within the first heat dissipation portion and communicates with the first gas-liquid channel. A cooling medium for gas-liquid conversion is disposed within the first gas-liquid channel, and the plurality of first flow channels are used to transport the cooling medium to the second gas-liquid channel. The included angle between the first gas-liquid channel and the second gas-liquid channel is 90 degrees or greater than 90 degrees and less than 180 degrees.

The circuit board has electronic components mounted on the side opposite to where the first power device is mounted. The first heat exchanger is located in the power cavity or the heat dissipation cavity. The first heat exchanger is used to transfer heat from the power cavity to the heat dissipation cavity to dissipate heat from the electronic components.

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

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

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

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

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

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

8. The power conversion device according to claim 7, characterized in that the power conversion device further includes a second heat exchanger, the second heat exchanger being used to transfer heat from the power cavity to the heat dissipation cavity, wherein both the first heat exchanger and the second heat exchanger are disposed within the heat dissipation cavity.

The first heat dissipation part and the second heat dissipation part are distributed in a vertical direction. The first substrate protrudes downward toward the first heat dissipation part, and the second substrate protrudes downward toward the second heat dissipation part. One of the first heat exchanger and the second heat exchanger is located between the first heat dissipation part and the second heat dissipation part, and the other is located below the one with the lower height of the first heat dissipation part and the second heat dissipation part.

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

10. The power conversion device according to claim 9, characterized in that both the first heat exchange channel and the second heat exchange channel extend along the second direction.

The first connecting pipe and the second connecting pipe are respectively located on different sides of the lower of the first heat dissipation part and the second heat dissipation part in the second direction.

The first direction, the second direction, and the vertical direction are perpendicular to each other.

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

12. The power conversion device according to claim 11, characterized in that the first heat dissipation part includes a plurality of spaced-apart first condenser tubes, the second heat dissipation part includes a plurality of spaced-apart second condenser tubes, and a plurality of fins are provided between adjacent two first condenser tubes and between adjacent two second condenser tubes.

In the first heat dissipation section and the second heat dissipation section, the number of fins provided in the section closer to the air inlet is less than the number of fins provided in the section farther from the air inlet.

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

14. The power conversion device according to any one of claims 1-10, wherein the included angle between the first gas-liquid channel and the second gas-liquid channel is greater than 90 degrees and less than or equal to 160 degrees.

15. The power conversion device according to any one of claims 1-10, characterized in that the first power device is fixedly connected to the first substrate by bolts, the circuit board is provided with a through hole for the head of the bolt to pass through, the shank of the bolt passes through the first power device and is threadedly connected to the first substrate, and the head of the bolt abuts against the surface of the first power device opposite to the first substrate.

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

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

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

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