Explosion-proof electrical box heat dissipation structure

Abstract

The invention relates to the technical field of anti-explosion electrical equipment, and discloses an anti-explosion electrical box heat dissipation structure which comprises a box body and a heating element, a plate type evaporator is arranged in the box body, a U-shaped evaporator is hung on the outer side of the plate type evaporator, the heating element is connected with the U-shaped evaporator, a back plate is arranged on the back of the box body, and a first condensation pipe is arranged outside the back plate. And a plurality of first fins are arranged on the first condensation pipe. Compared with the prior art, the device has the advantages that passive heat dissipation is relied on, electric spark risks are avoided, no mechanical moving part exists, the failure rate is low, the plate-shaped evaporator and the U-shaped evaporator are designed in a nested mode, the inner space of the box body is saved, step transfer of heat is achieved through two-way working medium phase change circulation heat transfer, and heat loads are effectively dispersed; the chimney effect of the first fins and the flow guide cover and capillary core working medium circulation are high in heat dissipation efficiency, heat dissipation is achieved through working medium phase change latent heat and natural convection, and energy consumption is extremely low.

Description

Technical Field

[0001] The invention relates to the technical field of explosion-proof electrical equipment, and in particular to a heat dissipation structure of an explosion-proof electrical box. Background Art

[0002] The heat dissipation structure design of explosion-proof electrical boxes is a key link to ensure their safe operation in flammable and explosive environments. Since explosion-proof equipment needs to be strictly sealed to prevent internal explosions or sparks from leaking out, while also effectively controlling internal temperature rise, its heat dissipation structure must take into account both explosion-proof performance and thermal management efficiency.

[0003] The heat dissipation structure of explosion-proof electrical boxes can be divided into natural heat dissipation, heat exchange heat dissipation and forced heat dissipation.

[0004] Natural heat dissipation usually chooses to add metal cooling fins on the surface of the box (usually the top or side) to increase the heat dissipation area and transfer the heat to the outside air. However, this method cannot effectively transfer the heat of the heating components inside the electrical box to the cooling fins, resulting in limited overall heat dissipation capacity of the cooling equipment and inability to cope with high temperature and high load scenarios.

[0005] Heat exchange heat dissipation usually chooses a water cooling / oil cooling system, which uses circulating coolant (water or oil) to remove heat. This method requires an explosion-proof pump and sealed pipeline. As a mechanical moving part, the circulating pump requires regular maintenance and has a certain cost of use.

[0006] Forced heat dissipation requires explosion-proof fans or air pumps. Explosion-proof air conditioners or semiconductor refrigeration can also be used, but the same explosion-proof fans and explosion-proof air conditioners also require regular maintenance to avoid failures. The initial equipment cost of explosion-proof air conditioners or semiconductor refrigeration is relatively high, and they can only be used in some precision instruments or high-temperature environments. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing heat dissipation structure of an explosion-proof electrical box has many limitations, and a heat dissipation structure of an explosion-proof electrical box is provided.

[0008] In order to solve the above technical problems, the technical solution provided by the present invention is: a heat dissipation structure of an explosion-proof electrical box, which includes a box body and a heating element, a box door is arranged on the front of the box body, a plate-type evaporator is arranged inside the box body, a U-shaped evaporator is suspended outside the plate-type evaporator, the heating element is connected to the U-shaped evaporator, a back plate is arranged on the back of the box body, a first condenser is arranged outside the back plate, and a plurality of first fins are arranged on the first condenser; A second condenser is provided in the plate-type evaporator, a liquid main is provided at one end of the second condenser, and a gas main is provided at the other end. The liquid main and the gas main extend to the outside of the plate-type evaporator. A liquid branch is provided on one side of the U-shaped evaporator to be connected to the liquid main, and a gas branch is provided on the other side to be connected to the gas main.

[0009] Furthermore, the first fin extends in the vertical direction, and a vertically penetrating flow guide cover is arranged outside the back plate, and the flow guide cover wraps the outside of the first fin.

[0010] Still further, a siphon cavity extending in the vertical direction is arranged on one side inside the plate-type evaporator, and a gas guide cavity extending in the vertical direction is arranged on the other side. A return channel is provided at the bottom of the plate-type evaporator to connect the gas guide cavity and the siphon cavity.

[0011] Even further, a steam interface is provided at the top of the first condensing pipe, and a liquid interface is provided at the bottom. A return interface is arranged at the bottom of the siphon cavity and connected to the liquid interface, and an exhaust interface is arranged at the top of the gas guide cavity and connected to the steam interface.

[0012] Even further, a plurality of evaporation channels are arranged inside the plate-type evaporator and an F-shaped capillary core is nested. Among them, the evaporation channels communicate the siphon cavity and the gas guide cavity. The vertical part of the F-shaped capillary core is nested in the siphon cavity, the straight part is nested in the evaporation channels, and the second condensing pipe is nested in the straight part of the F-shaped capillary core.

[0013] Even further, the second condensing pipe is inclined, and the end close to the siphon cavity is lower than the other end. The straight part of the F-shaped capillary core and the evaporation channels are also inclined at the same angle. A plurality of first steam grooves are arranged on the inner wall of the evaporation channels along the inclined direction, and the ends of the first steam grooves extend into the gas guide cavity.

[0014] Even further, a bent cover plate is arranged at the top of the U-shaped evaporator. A liquid storage cavity is arranged on one side inside, and an evaporation cavity is arranged on the other side. A liquid supply channel is arranged at the bottom of the U-shaped evaporator to connect the liquid storage cavity and the evaporation cavity. A heat conduction plate is arranged in the evaporation cavity and is attached to the heating element.

[0015] Even further, a plurality of second fins extending in the vertical direction are arranged on the side of the heat conduction plate close to the evaporation cavity. A plate-type capillary core is nested between the second fins, and a plurality of second steam grooves extending in the vertical direction are arranged on the side walls of the second fins.

[0016] Even further, the liquid branch pipe communicates with the top of the liquid storage cavity, and the gas branch pipe communicates with the top of the evaporation cavity.

[0017] Compared with the prior art, the present invention has the following advantages: 1. The present invention completely relies on passive heat dissipation and can avoid the risk of electric sparks.

[0018] 2. The present invention has no mechanical moving parts and has a low failure rate.

[0019] 3. In the present invention, the plate-type evaporator and the U-shaped evaporator are nested, which saves the internal space of the box body.

[0020] 4. Through the phase change cycle heat transfer of two working fluids, the present invention realizes the cascade transfer of heat, effectively disperses the heat load, and the chimney effect of the first fin + flow guide cover and the capillary core working fluid cycle cooperate to improve the heat dissipation efficiency.

[0021] 5. The present invention utilizes the latent heat of phase change of the working fluid and natural convection heat dissipation, with extremely low energy consumption, meeting the trend of green manufacturing. Brief Description of the Drawings

[0022] Figure 1 is the structural schematic diagram of the present invention.

[0023] Figure 2 is the structural schematic diagram of the back side of the present invention.

[0024] Figure 3 is the structural schematic diagram of the present invention with the box door open.

[0025] Figure 4 is the structural schematic diagram of the first fin of the present invention.

[0026] Figure 5 is the exploded structural schematic diagram of the front side of the box body of the present invention.

[0027] Figure 6 is the exploded structural schematic diagram of the back side of the box body of the present invention.

[0028] Figure 7 is the exploded structural schematic diagram of the plate-type evaporator of the present invention.

[0029] Figure 8 is the structural schematic diagram of the U-shaped evaporator of the present invention.

[0030] Figure 9 is the exploded structural schematic diagram of the U-shaped evaporator of the present invention.

[0031] Figure 10 is the internal structural schematic diagram of the U-shaped evaporator of the present invention.

[0032] As shown in the figure: 1. Box body, 2. Box door, 3. Flow guide cover, 4. Heating element, 5. U-shaped evaporator, 6. Plate-type evaporator, 7. Liquid main pipe, 8. Gas main pipe, 9. Back plate, 10. First condensing pipe, 11. First fin, 12. Steam interface, 13. Liquid interface, 14. Exhaust interface, 15. Return interface, 16. Siphon cavity, 17. Air guide cavity, 18. Evaporation channel, 19. First steam tank, 20. Return channel, 21. F-type capillary core, 22. Second condensing pipe, 23. Bent cover plate, 24. Heat conducting plate, 25. Liquid branch pipe, 26. Gas branch pipe, 27. Liquid storage cavity, 28. Liquid supply channel, 29. Evaporation cavity, 30. Second fin, 31. Second steam tank, 32. Plate-type capillary core. Detailed Embodiments

[0033] The present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Combined with the attached Figure 1 and the attached Figure 2 and the attached Figure 3 and the attached Figure 4 , an explosion-proof electrical box heat dissipation structure, which includes a box body 1 and a heating element 4. A box door 2 is provided on the front of the box body 1, and a plate-shaped evaporator 6 is provided inside. A U-shaped evaporator 5 is suspended outside the plate-shaped evaporator 6. The heating element 4 is connected to the U-shaped evaporator 5. A back plate 9 is provided on the back of the box body 1, and a first condenser tube 10 is provided outside the back plate 9. A plurality of first fins 11 are provided on the first condenser tube 10. The back plate 9 is welded to the back side of the box body 1 to form an explosion-proof sealed isolation.

[0035] Combined with the attached Figure 8 and the attached Figure 9 and the attached Figure 10 , a bent cover plate 23 is provided at the top of the U-shaped evaporator 5. A liquid storage cavity 27 is provided on one side inside, and an evaporation cavity 29 is provided on the other side. A liquid supply channel 28 is provided at the bottom of the U-shaped evaporator 5 to connect the liquid storage cavity 27 and the evaporation cavity 29. A heat conduction plate 24 is provided in the evaporation cavity 29 and is attached to the heating element 4.

[0036] Combined with the attached Figure 9 and the attached Figure 10 , a plurality of second fins 30 extending in the vertical direction are provided on the side of the heat conduction plate 24 close to the evaporation cavity 29. A plate-shaped capillary core 32 is nested between the second fins 30. A plurality of second steam grooves 31 extending in the vertical direction are provided on the side walls of the second fins 30.

[0037] Combined with the attached Figure 7 , a second condenser tube 22 is provided inside the plate-shaped evaporator 6. One end of the second condenser tube 22 is provided with a liquid main pipe 7, and the other end is provided with a gas main pipe 8. The liquid main pipe 7 and the gas main pipe 8 extend outside the plate-shaped evaporator 6. A liquid branch pipe 25 is provided in the liquid storage cavity 27 of the U-shaped evaporator 5 and is connected to the liquid main pipe 7. A gas branch pipe 26 is provided in the evaporation cavity 29 and is connected to the gas main pipe 8.

[0038] In the above structure, the U-shaped evaporator 5 absorbs the heat generated by the operation of the heating element 4 and transfers it to the second condenser tube 22 inside the plate-shaped evaporator 6 as the first heat transfer structure. All connections on the pipeline connection path involved in the first heat transfer structure are welded to ensure airtightness, so that the first heat transfer structure forms a constant volume environment.

[0039] Since the heating element 4 in the common electrical box, such as the IGBT module, is a composite fully controlled voltage-driven power semiconductor device, which is usually used to achieve efficient power conversion and control in high-voltage and high-current scenarios, it is the main heating element in most electrical boxes. Its existing radiator target temperature is usually set at 80°C. Therefore, the working fluid in the first heat transfer structure adopts an electronic fluoride liquid with a boiling point below 80°C, such as 3M Novec 7200 with a boiling point of 76°C.

[0040] The U-shaped evaporator 5 can store a certain amount of liquid working medium in the liquid storage chamber 27, the liquid supply channel 28 and the bottom of the evaporation chamber 29 through its own contour. At the same time, the plate-type capillary wick 32 in the evaporation chamber 29 continuously absorbs the liquid working medium through the capillary effect. When the heating element 4 is working, the heat generated by it is first transferred to the heat conducting plate 24 to increase the temperature of the second fin 30 and its nested plate-type capillary wick 32. When the temperature reaches the boiling point of the liquid working medium, the liquid working medium in the plate-type capillary wick 32 near the second fin 30 begins to vaporize, and under the guidance of the second steam groove 31, it continuously rises to the top of the evaporation chamber 29, enters the gas branch pipe 26 and then merges into the gas main pipe 8. Finally, the gaseous working medium enters the second condenser 22. When the second condenser 22 is cooled and the internal temperature reaches the liquefaction temperature of the gaseous working medium, the gaseous working medium is converted into liquid again in the second condenser 22. The condensed liquid working medium enters the liquid main pipe 7 and is diverted to the liquid branch pipe 25, and finally returns to the liquid storage chamber 27 to complete the cycle.

[0041] In order to ensure that the liquid working medium in the second condenser 22 cannot enter the gas main pipe 8, and the gaseous working medium cannot enter the liquid main pipe 7, the second condenser 22 is arranged at an angle, wherein the height of the end connected to the liquid main pipe 7 is lower than the other end. In addition, in order to ensure that the condensed liquid working medium can smoothly flow back to the liquid storage chamber 27, the installation height of the U-shaped evaporator 5 needs to ensure that the height of the connection between the liquid storage chamber 27 and the liquid branch pipe 25 is lower than the lowest point of the inclined second condenser 22.

[0042] Combined with Figure 3 and attached Figure 6 The first fin 11 extends in the vertical direction, and a guide cover 3 penetrating in the vertical direction is arranged outside the back plate 9 , and the guide cover 3 is wrapped around the outside of the first fin 11 .

[0043] To meet the explosion-proof requirements of the electrical box, instead of using a power component to transfer the second condenser tube 22 to the external air of the box body 1 for cooling, a vertical first fin 11 is used in cooperation with a flow guide cover 3 to form a vertical air circulation channel, transferring the heat of the second condenser tube 22 to the first fin 11 and heating the air around it. The heated air has a reduced density and continuously rises, eventually discharging from the top of the flow guide cover 3. Since the air around the first fin 11 is heated and discharged to form a local low pressure, fresh air is continuously inhaled through the flow guide cover 3 and heated and discharged again by the first fin 11, realizing the circulation of cooling air in the form of the chimney effect.

[0044] If the second condenser tube 22 is directly welded to the first fin 11 to form the structure of a finned heat exchanger, due to the short length of the tube body of the second condenser tube 22, it is impossible to form a sufficient heat exchange area with the first fin 11, resulting in limited heat transfer effect. If a corrugated elbow with a longer tube length is selected for the second condenser tube 22 to ensure a sufficient heat exchange area with the first fin 11, it will lead to an excessive height difference between the liquid main pipe 7 and the gas main pipe 8, making it difficult to install the U-shaped evaporator 5 normally. Therefore, a plate-type evaporator 6 is used to absorb the heat from the second condenser tube 22 and transfer it to the first condenser tube 10, and the first condenser tube 10 is selected as a corrugated elbow and welded to the first fin 11.

[0045] Combined with Fig. Figure 5 、Fig. Figure 6 and Fig. Figure 7 As shown, a siphon cavity 16 extending in the vertical direction is arranged on one side inside the plate-type evaporator 6, and a gas guide cavity 17 extending in the vertical direction is arranged on the other side. A return channel 20 is provided at the bottom of the plate-type evaporator 6 to connect the gas guide cavity 17 with the siphon cavity 16. A steam interface 12 is provided at the top of the first condenser tube 10, and a liquid interface 13 is provided at the bottom. A return interface 15 is arranged at the bottom of the siphon cavity 16 and connected to the liquid interface 13, and an exhaust interface 14 is arranged at the top of the gas guide cavity 17 and connected to the steam interface 12.

[0046] The plate-type evaporator 6 absorbs the heat brought by the second condenser tube 22 and transfers it to the first condenser tube 10, and the first fin 11 transfers the heat to the external air as the second heat transfer structure. To ensure that the temperature of the second condenser tube 22 is sufficient to evaporate the working medium in the plate-type evaporator 6, the boiling point of the working medium of the second heat transfer structure needs to be lower than that of the electronic fluorinated liquid in the first heat transfer structure. Therefore, the working medium of the second heat transfer structure uses methanol with a boiling point of 64.7 °C.

[0047] The temperature of the gaseous electronic fluorinated liquid entering the second condenser 22 is greater than or equal to its own boiling point. Therefore, the temperature of the second condenser 22 is greater than the boiling point of methanol in the plate evaporator 6. When the liquid methanol comes into contact with the second condenser 22, it absorbs heat and forms gaseous methanol, causing the heat of the gaseous electronic fluorinated liquid in the second condenser 22 to decrease and turn into a liquid state. The gaseous methanol in the plate evaporator 6 continuously gathers upward and enters the first condenser 10 through the exhaust interface 14. The heat is transferred to the external air through the first fins 11 and turns back into a liquid state, and then returns to the plate evaporator 6 through the reflux interface 15.

[0048] The siphon chamber 16 can keep the liquid level height of the liquid methanol inside it consistent with the liquid level height in the first condenser 10 through the siphon effect. However, since the second condenser 22 is horizontally placed with a small inclination inside the plate evaporator 6, a higher liquid level of the liquid methanol is required to make full contact with the second condenser 22.

[0049] To sum up, in combination with the attached Figure 7 , a plurality of evaporation channels 18 are arranged inside the plate evaporator 6 and the F-shaped capillary core 21 is nested. Among them, the evaporation channels 18 connect the siphon chamber 16 and the air guide chamber 17. The vertical part of the F-shaped capillary core 21 is nested inside the siphon chamber 16, and the straight part is nested inside the evaporation channels 18. The second condenser 22 is nested inside the straight part of the F-shaped capillary core 21.

[0050] Combined with the attached drawings, the second condenser 22 is inclined, and the straight part of the F-shaped capillary core 21 and the evaporation channels 18 are also inclined at the same angle. A plurality of first steam grooves 19 are arranged on the inner wall of the evaporation channels 18 along their inclined direction, and the ends of the first steam grooves 19 extend into the air guide chamber 17.

[0051] The F-shaped capillary core 21 can continuously suck the liquid methanol through the capillary effect. The liquid methanol can continuously flow inside the porous capillary structure of the F-shaped capillary core 21 until the F-shaped capillary core 21 is completely filled and wetted. The second condenser 22 continuously heats the surrounding F-shaped capillary core 21, causing the liquid methanol here to vaporize. The gaseous methanol moves in the evaporation channels 18 through the first steam grooves 19 and finally gathers in the air guide chamber 17 and enters the exhaust interface 14.

[0052] Since the first condenser 10 needs to rely on the chimney effect of the first fins 11 to achieve convective heat transfer, the first fins 11 need to have a certain height. Refer to the attached Figure 4, the vertical height of the first fin 11 is approximately equivalent to the height of the box body 1. The steam interface 12 of the first condenser tube 10 needs to be close to the top of the first fin 11, and the liquid interface 13 needs to be close to the bottom of the first fin 11. There is a certain height difference between the steam interface 12 and the liquid interface 13. Therefore, the vertical part in the F-shaped capillary core 21 needs to lift the methanol liquid level to the height of the evaporation channel 18 by capillary force to resist the gravity of the liquid working medium.

[0053] Now assume that the height difference between the evaporation channel 18 and the reflux interface 15 is h meters, and the density of methanol is ρ. Then the capillary pressure P required to lift the methanol liquid level satisfies the following relationship:

[0054] Among them, the density of methanol is approximately 800 kg / m at 60 °C 3 , and g is taken as 9.8 N / kg; Then ; Therefore, for every 1 m of the height difference between the evaporation channel 18 and the reflux interface 15, about 7840 Pa of pressure needs to be provided for capillary suction.

[0055] The capillary pressure that the capillary core can provide satisfies the following relationship:

[0056] Among them, σ is the surface tension of the working medium, θ is the contact angle between the working medium and the capillary material, and r is the equivalent pore diameter of the capillary structure.

[0057] The surface tension of methanol is inversely proportional to its temperature. There are existing experimental tests on the relationship between the surface tension of methanol and its temperature at 20 °C to 60 °C: Wu Meng, Determination and Analysis of the Surface Tension of Alcohol Absorbents for Gas Purification, "Shandong Industrial Technology", Issue 21, 2014, pp. 78-79. Since the temperature of the liquid methanol in this device is lower than the boiling point, the surface tension of methanol is temporarily taken as 0.0216 N / m corresponding to 60 °C.

[0058] The equivalent pore diameter of the currently common ceramic microporous capillary core is between 0.5 μm and 5 μm. Through plasma treatment or structured design, a state with a wetting angle lower than 10° can be achieved. Therefore, cosθ = 0.98 is temporarily taken.

[0059] To sum up, when the F-shaped capillary core 21 needs to lift methanol by h meters each time, the required equivalent capillary pore diameter is , referring to the height of a conventional explosion-proof electric box, h < 2 meters. Obviously, the conventional ceramic microporous capillary core can meet the pressure required for the liquid methanol reflux in the plate-type evaporator 6. At the same time, there is a siphon effect in the siphon chamber 16 to keep the methanol liquid level inside the same as the liquid level inside the first condenser tube 10, and the actual suction pressure required for the liquid methanol reflux will be smaller.

[0060] In summary, the internal structure of the plate evaporator 6 can achieve the reverse gravity reflux of the liquid working medium without external power.

[0061] The present invention and its implementation manners have been described above. Such description is not restrictive, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar structural manners and embodiments without creative efforts without departing from the spirit of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. An explosion-proof electrical box heat dissipation structure, which includes a box body (1) and a heating element (4), and a box door (2) is arranged on the front of the box body (1), and is characterized in that: Inside the box body (1), there is a plate-type evaporator (6). A U-shaped evaporator (5) is suspended outside the plate-type evaporator (6). The heating element (4) is connected to the U-shaped evaporator (5). A back plate (9) is provided on the back of the box body (1), and a first condenser tube (10) is arranged outside the back plate (9). A plurality of first fins (11) are arranged on the first condenser tube (10). Inside the plate-type evaporator (6), there is a second condenser tube (22). One end of the second condenser tube (22) is provided with a liquid main pipe (7), and the other end is provided with a gas main pipe (8). The liquid main pipe (7) and the gas main pipe (8) extend outside the plate-type evaporator (6). A liquid branch pipe (25) is arranged on one side of the U-shaped evaporator (5) and connected to the liquid main pipe (7), and a gas branch pipe (26) is arranged on the other side and connected to the gas main pipe (8).

2. The heat dissipation structure of the explosion-proof electrical box according to claim 1, characterized in that: The first fins (11) extend in the vertical direction. A vertically penetrating flow guide cover (3) is arranged outside the back plate (9), and the flow guide cover (3) wraps outside the first fins (11).

3. The heat dissipation structure of the explosion-proof electrical box according to claim 1, wherein: On one side inside the plate-type evaporator (6), there is a siphon cavity (16) extending in the vertical direction, and on the other side, there is a gas guide cavity (17) extending in the vertical direction. A return channel (20) is provided at the bottom of the plate-type evaporator (6) to connect the gas guide cavity (17) with the siphon cavity (16).

4. The heat dissipation structure of the explosion-proof electrical box according to claim 3, wherein: The top of the first condenser tube (10) is provided with a steam interface (12), and the bottom is provided with a liquid interface (13). A return interface (15) is arranged at the bottom of the siphon cavity (16) and connected to the liquid interface (13). An exhaust interface (14) is arranged at the top of the gas guide cavity (17) and connected to the steam interface (12).

5. The heat dissipation structure of the explosion-proof electrical box according to claim 3, characterized in that: A plurality of evaporation channels (18) are arranged inside the plate-type evaporator (6) and an F-shaped capillary core (21) is nested. The evaporation channels (18) communicate the siphon cavity (16) with the gas guide cavity (17). The vertical part of the F-shaped capillary core (21) is nested in the siphon cavity (16), and the straight part is nested in the evaporation channels (18). The second condenser tube (22) is nested in the straight part of the F-shaped capillary core (21).

6. The heat dissipation structure of the explosion-proof electrical box according to claim 5, wherein: The second condenser tube (22) is inclined, with the end close to the siphon cavity (16) lower than the other end. The straight part of the F-shaped capillary core (21) and the evaporation channels (18) are also inclined at the same angle. A plurality of first steam grooves (19) are arranged on the inner wall of the evaporation channels (18) along the inclined direction, and the ends of the first steam grooves (19) extend into the gas guide cavity (17).

7. The heat dissipation structure of the explosion-proof electrical box according to claim 1, characterized in that: A bent cover plate (23) is arranged at the top of the U-shaped evaporator (5). A liquid storage cavity (27) is arranged on one side inside, and an evaporation cavity (29) is arranged on the other side. A liquid supply channel (28) is arranged at the bottom of the U-shaped evaporator (5) to connect the liquid storage cavity (27) with the evaporation cavity (29). A heat conducting plate (24) is arranged in the evaporation cavity (29) and attached to the heating element (4).

8. The heat dissipation structure of the explosion-proof electrical box according to claim 7, characterized in that: On the side of the heat conducting plate (24) close to the evaporation cavity (29), a plurality of second fins (30) extending in the vertical direction are arranged. A plate-type capillary core (32) is nested between the second fins (30). A plurality of second steam grooves (31) extending in the vertical direction are arranged on the side walls of the second fins (30).

9. The heat dissipation structure of the explosion-proof electrical box according to claim 7, wherein: The liquid branch pipe (25) communicates with the top of the liquid storage cavity (27), and the gas branch pipe (26) communicates with the top of the evaporation cavity (29).

Images