A heat-driven cycle method, a multi-stage heat dissipation structure and an explosion-proof pressure relief electric appliance cabinet

Abstract

The application discloses a heat-driven circulation method, a multi-stage heat dissipation structure and an explosion-proof pressure relief electric appliance cabinet, and relates to the technical field of electric appliance cabinet heat dissipation. In the first step, the low-temperature airflow from the outside is introduced into the first functional area with the first equivalent flow cross section. The application sets a shunt channel on the upstream of the airflow path, so that most of the airflow directly enters the third functional area for heat and moisture exchange, and a small part of the airflow enters the second functional area for generating local negative pressure, thereby realizing the topological separation of the negative pressure suction function and the heat and moisture exchange function. The shunt design avoids the simple reduced-diameter nozzle structure formed by introducing all the airflow into the reduced-diameter section, and the suction function and the heat exchange function are independent of each other and do not compete with each other, so that the suction efficiency and the heat exchange efficiency can be considered in the same system.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electrical cabinets, specifically to a heat dissipation and thermal runaway protection structure for electrical cabinets used to install batteries, and particularly to a thermally driven circulation method, a multi-stage heat dissipation structure, and an explosion-proof pressure relief electrical cabinet. Background Technology

[0002] Traditional appliance cabinet cooling typically employs forced ventilation with fans or natural convection, using vents within the cabinet to facilitate air exchange. For example, forced ventilation systems use rotating blades to create a pressure difference, driving airflow to expel hot internal air while cool external air naturally enters. Natural convection systems, on the other hand, utilize the buoyancy effect of rising hot air and sinking cool air to create circulation. Both methods rely on vents in the cabinet walls for airflow, but these traditional cooling solutions have several inherent drawbacks.

[0003] Firstly, the technical solutions disclosed in Chinese patents CN210008081U, CN104269758A, and CN107681514A all require the installation of a negative pressure fan as a power source on the top or side wall of the cabinet. This design results in moving parts in the cooling system, leading to reliability issues such as bearing wear, blade dust accumulation, and motor aging during long-term operation. Furthermore, the fan operation generates additional noise and energy consumption. More importantly, if the fan fails, the entire cooling system fails. For battery energy storage systems that require continuous operation, this single point of failure poses a significant safety hazard.

[0004] Secondly, although the technical solution disclosed in Chinese patent CN113381326A achieves the ventilation function, the airflow lacks a directional guidance mechanism after it diffuses inside the cabinet. The deep part of the cabinet (especially the bottom of the battery compartment and the back panel area) is far from the ventilation opening, forming an airflow dead zone. Hot air stagnates and accumulates for a long time, resulting in the continuous existence of local hot spots, which accelerates the aging and degradation of the battery cells.

[0005] Third, when a battery experiences thermal runaway, a violent exothermic side reaction occurs inside the cell, releasing a large amount of high-temperature, high-pressure gas carrying conductive carbon particles and flammable electrolyte droplets in a short period. Existing heat dissipation technologies design vents and ducts for conventional cooling conditions, neglecting the need for particle interception and flame quenching under these extreme conditions. For example, all the aforementioned technologies focus only on conventional circulating cooling and lack design to block ejected materials.

[0006] Fourth, existing technical solutions all treat the electrical cabinet as a single thermal environment cavity for heat dissipation design, failing to recognize the differences in heat tolerance between power components (heat-generating surfaces) and battery cells (temperature-sensitive surfaces). The high-temperature airflow generated during the heat dissipation process of the components diffuses freely within the cabinet, causing additional thermal radiation and thermal convection impacts on the battery cells, further shortening the effective lifespan of the batteries.

[0007] To address the technical problems in traditional technologies, such as fan dependence leading to limited reliability, unclear airflow organization path causing stagnant hot air inside the cabinet, lack of thermal runaway protection, and thermal isolation between heat sources and sensitive components, this invention proposes a thermally driven circulation method, a multi-stage heat dissipation structure, and an explosion-proof pressure relief electrical cabinet. Summary of the Invention

[0008] To address the technical problems in traditional technologies, such as fan reliance leading to limited reliability, unclear airflow organization paths causing stagnant hot air inside the cabinet, lack of thermal runaway protection, and insufficient thermal isolation between heat sources and sensitive components, this invention proposes a thermally driven circulation method, a multi-stage heat dissipation structure, and an explosion-proof pressure relief electrical cabinet. The technical solution of this invention is achieved through the following steps.

[0009] The first aspect is a thermally driven cycle method.

[0010] The heat-driven circulation method described in this invention is mainly used to dissipate heat from the internal environment of an electrical cabinet through gas circulation force. The gas circulation force originates from the thermal buoyancy caused by the airflow temperature difference and / or the pressure difference generated by the abrupt change in the flow cross-section. The heat-driven circulation method includes the following steps.

[0011] The first step is to allow the external low-temperature airflow to flow into the first functional area with a first equivalent flow cross section. The expansion effect of the volume of the first functional area is used to eliminate the turbulent pulsating component in the low-temperature airflow, so that the low-temperature airflow is transformed into a state of flow along a preset direction.

[0012] The second step involves passing the low-temperature airflow through a second functional region having a second equivalent flow cross-section smaller than the first equivalent flow cross-section, thereby increasing the flow velocity and decreasing the static pressure of the low-temperature airflow in the second functional region, thus forming a local negative pressure zone in the second functional region with a pressure lower than that of the internal environment.

[0013] The third step involves using the pressure difference between the local negative pressure zone and the internal environment to draw the high-temperature airflow inside the electrical cabinet into the low-temperature airflow through the ejection channel that connects the second functional area and the internal environment, thereby forming a mixed airflow.

[0014] The fourth step is to return the mixed airflow to the internal environment until the heat dissipation function is completed.

[0015] In one embodiment, the first functional area, the second functional area, and the third functional area are all integrated inside the wall base of the electrical cabinet.

[0016] In one embodiment, before the low-temperature airflow enters the second functional region, the low-temperature airflow first flows through a diversion channel located upstream of the third functional region, where a portion of the airflow is guided into the third functional region to participate in heat exchange, and another portion of the airflow enters the second functional region to generate local negative pressure; the mass flow rate of the airflow entering the second functional region is less than the mass flow rate of the airflow entering the third functional region.

[0017] In one embodiment, after the mixed airflow is formed, the mixed airflow is subjected to heat and moisture exchange with the heat and moisture exchange medium disposed inside the third functional area, and the heat and moisture exchange treated airflow is returned to the internal environment.

[0018] Secondly, a multi-stage heat dissipation structure.

[0019] The multi-stage heat dissipation structure is used to implement the heat-driven cycle method as described in the first aspect; the multi-stage heat dissipation structure includes an air intake structure, which mainly includes the following structure.

[0020] A wall base is integrated into the wall of the electrical cabinet; and a first cavity with a first volume for voltage stabilization is opened inside the wall base, wherein the wall of the first cavity has an air inlet for connecting to the outside atmosphere.

[0021] The air intake structure further includes a second cavity with a second volume, which is opened inside the wall substrate and is connected to the downstream of the first cavity through a first airflow channel. The equivalent flow cross section of the second cavity is smaller than that of the first cavity, so that the airflow after lamination in the first cavity increases in velocity and decreases in static pressure when it enters the second cavity, thereby forming the local negative pressure zone. The air intake structure further includes a third cavity with a third volume, which is opened inside the wall matrix. The third cavity is connected to the downstream of the first cavity through a second airflow channel. The second airflow channel and the first airflow channel are arranged in parallel branches on the downstream side of the first cavity, so that the airflow after lamination in the first cavity can be split into a first part entering the third cavity and a second part entering the second cavity. The air intake structure also includes a feedback channel formed by a narrowed-diameter connecting pipe inside the wall substrate, with one end connected to the second cavity and the other end connected to the internal environment, so that the local negative pressure zone draws in the airflow of the internal space of the electrical cabinet through the feedback channel.

[0022] In one embodiment, the volume dimensions of the first cavity, the second cavity, and the third cavity are configured such that the first cavity can accommodate external airflow entering through the air inlet and convert the airflow into a laminar flow state.

[0023] One approach is to have a volume greater than that of either the second or the third cavity.

[0024] Another approach is to have the volume of the first cavity greater than the volume of the second cavity, and the volume of the second cavity greater than the volume of the third cavity, so that the multi-stage heat dissipation structure forms a pressure gradient field that decreases from the first cavity to the third cavity.

[0025] In one embodiment, the equivalent flow area of ​​the second airflow channel is larger than the equivalent flow area of ​​the first airflow channel, so that the mass flow rate of the first part is greater than the mass flow rate of the second part.

[0026] In one embodiment, the third cavity is provided with a heat and humidity exchange medium so that when the first part of the airflow flows through the third cavity, it can exchange heat and transfer humidity with the heat and humidity exchange medium.

[0027] In one embodiment, the feedback channel is located at the opening of the internal environment, and the feedback channel is lower than the outlet position of the airflow fed into the internal environment by the third cavity, so that when the airflow after heat and moisture exchange treatment is discharged from the outlet position, it can move upward by means of thermal buoyancy, and the airflow entrained by the feedback channel comes from the low-level region of the internal environment.

[0028] In one embodiment, the third cavity is provided with a heat exchange chamber, and the heat and moisture exchange medium includes: a microchannel plate and a porous sieve substrate arranged in layers and installed in the heat exchange chamber. At least one of the microchannel plate and the porous sieve substrate is coated with a phase change material coating so that the first part of the airflow flowing through the third cavity can complete heat absorption and latent heat transfer through the phase change process of the phase change material coating when passing through the microchannel plate and the porous sieve substrate.

[0029] In one embodiment, an exhaust structure is also included, the exhaust structure including a support base, the second base being integrated into the wall of the electrical cabinet and arranged opposite to the wall base, the second base having a mesh area and fins, so that the airflow inside the electrical cabinet is discharged to the outside atmosphere through the mesh area after heat exchange via the fins.

[0030] Thirdly, an explosion-proof pressure relief electrical cabinet.

[0031] The explosion-proof pressure relief electrical cabinet includes a cabinet body, and the explosion-proof pressure relief electrical cabinet also includes an isolation structure that divides the interior of the cabinet body into multiple working chambers, for example, dividing it into a first working chamber and a second working chamber, so that a portion of the working chamber is used to accommodate heat-generating components and another portion of the working chamber is used to accommodate battery units.

[0032] The explosion-proof pressure relief electrical cabinet also includes a multi-stage heat dissipation structure as described in the second aspect, the multi-stage heat dissipation structure being installed on the wall surface of the cabinet; wherein the wall surface base and the support base can respectively serve as the door of the explosion-proof pressure relief electrical cabinet; The feed outlet of the third cavity of the multi-stage heat dissipation structure, which feeds airflow into the internal space of the cabinet, is opened on the wall of the second working cavity, so that the airflow after heat and moisture exchange treatment by the third cavity is fed into the interior of the second working cavity. The feedback channel of the multi-stage heat dissipation structure is opened on the wall of the second working chamber through the opening of the internal space of the cabinet, so that the local negative pressure zone formed in the second chamber can draw in the airflow inside the second working chamber through the feedback channel. The microchannel plate and the microporous structure of the porous sieve substrate inside the third cavity are configured such that, when the battery cell experiences thermal runaway, the microporous structure throttles and impedes the high-temperature and high-pressure gas and ejected particles generated in the second working cavity, thereby reducing the flow rate and temperature of the high-temperature and high-pressure gas and ejected particles as they pass through the microchannel plate and the porous sieve substrate, thus preventing flames or high-temperature airflow from directly entering the first working cavity.

[0033] Compared with the prior art, the beneficial effects of the present invention are: Firstly, this invention achieves topological separation between the negative pressure entrainment function and the heat and moisture exchange function by setting a diversion channel upstream of the airflow path, allowing most of the airflow to directly enter the third functional area for heat and moisture exchange, while a small portion of the airflow enters the second functional area to generate local negative pressure. This diversion design avoids the simple diameter-reducing nozzle structure formed by directing all airflow into the diameter-reducing section. The entrainment and heat exchange functions are independent and do not compete with each other, allowing both entrainment efficiency and heat exchange efficiency to be achieved within the same system.

[0034] Secondly, this invention utilizes the geometric difference in the equivalent flow cross-section between the first and second chambers to create a narrowing effect. This causes the airflow to accelerate and depressurize at the point of abrupt change in cross-section, forming a local negative pressure zone. This local negative pressure zone continuously draws in hot air from inside the chamber via a feedback channel and maintains automatic replenishment of external airflow through the inlet, thus forming a self-sustaining cycle that requires no external mechanical input. This passive drive mechanism eliminates the reliability and energy consumption problems caused by moving parts at the principle level.

[0035] Thirdly, this invention places the return air outlet at a high position and the ejector channel connection at a low position. Utilizing the increased air density and natural sinking properties of the airflow after heat and moisture exchange treatment, the treated airflow covers the entire internal space from top to bottom along the cabinet height direction, and is then drawn back through the low-position ejector inlet. This coordinated spatial layout of high-position feed and low-position suction transforms thermal buoyancy from an interference factor that needs to be overcome in traditional solutions into a usable auxiliary driving force. It ensures that the airflow organization direction is consistent with rather than opposed to the natural convection direction, avoiding the problems of airflow short-circuiting and heat stagnation and accumulation deep within the cabinet that occur in traditional solutions.

[0036] Fourth, the present invention enables the third chamber to simultaneously achieve enhanced convection heat transfer, humidity control and catalytic decomposition of harmful gases within a limited space by stacking microchannel plates and porous sieve substrates and coating at least one of them with phase change material.

[0037] Fifth, this invention uses an isolation structure to divide the cabinet into a second working chamber and a first working chamber, spatially isolating the heat-generating components and battery cells, and prioritizing thermal management resources for the more sensitive battery side. Simultaneously, the microchannel plate and the microporous structure of the porous sieve substrate in the heat dissipation structure automatically perform throttling and flame quenching functions under thermal runaway conditions, achieving the reuse of heat exchange functions under normal operating conditions and flame-retardant functions under extreme conditions using the same physical component. Attached Figure Description

[0038] Figure 1 This is a schematic flowchart of the thermally driven cycle method of the present invention.

[0039] Figure 2 This is a simplified schematic diagram illustrating the principle of the thermally driven cycle method of the present invention.

[0040] Figure 3 This is a three-dimensional schematic diagram of the explosion-proof pressure relief electrical cabinet of the present invention.

[0041] Figure 4 This is a three-dimensional schematic diagram of the internal structure of the explosion-proof pressure relief electrical cabinet of the present invention.

[0042] Figure 5 This is a three-dimensional schematic diagram of the exhaust structure of the present invention.

[0043] Figure 6 For the present invention Figure 5 A magnified view of area A.

[0044] Figure 7 This is a three-dimensional structural diagram of the air intake structure of the present invention.

[0045] Figure 8 This is a side-view cross-sectional schematic diagram of the air intake structure of the present invention.

[0046] Figure 9 For the present invention Figure 8 A magnified view of areas C and D.

[0047] Figure 10 This is a schematic diagram of the intake structure principle of the present invention.

[0048] Figure descriptions: 1. Cabinet; 11. First working chamber; 12. Second working chamber; 13. Isolation structure; 14. Shelf; 2. Air intake structure; 21. Wall substrate; 22. Air inlet; 23. First chamber; 24. Second chamber; 241. Feedback channel; 25. Third chamber; 251. Heat exchange chamber; 252. Guide plate; 253. Microchannel plate; 254. Porous sieve substrate; 3. Exhaust structure; 31. Support substrate; 32. Mesh area; 33. Fin plate. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] Example 1. This example first provides a multi-stage heat dissipation structure. This structure is used to achieve passive heat dissipation inside the electrical cabinet by utilizing the hydrodynamic effect generated when airflow passes through a variable cross-section channel, without an external mechanical power source. This avoids the problem of insufficient long-term operational reliability caused by existing technologies that rely on active power sources such as negative pressure fans to generate pressure differences to drive airflow and have moving parts. The multi-stage heat dissipation structure provided in this example solves the above problems at the structural level by integrating functional chambers inside the wall substrate and utilizing the difference in equivalent flow cross-section between each chamber to form a pressure gradient.

[0051] In this embodiment, please refer to Figure 4-5 ,as well as Figure 7 The multi-stage heat dissipation structure includes a wall base 21, which is integrated into the wall of the electrical cabinet. The wall base 21 serves as the load-bearing foundation for each functional chamber, and its thickness is configured to provide sufficient space to accommodate the openings of these chambers. It is understood that the wall base 21 can be constructed as any one of the door structure, side panel structure, or rear panel structure of the electrical cabinet, depending on the overall layout design of the electrical cabinet.

[0052] Specifically, a first cavity 23 is formed inside the wall substrate 21. The first cavity 23 has a first volume, and its wall has an air inlet 22 that connects to the outside atmosphere to introduce low-temperature airflow into the first cavity 23. The first cavity 23 is configured to have an expansion volume. When the low-temperature airflow flows into the first cavity 23 through the air inlet 22, the airflow velocity decreases and the flow direction tends to become uniform due to the volume expansion effect of the first cavity 23. This eliminates the turbulent pulsation component in the outside airflow caused by environmental factors, transforming the airflow into a laminar flow state along a preset direction. This laminarization process is essential for the stable flow of downstream airflow—if the airflow entering the second cavity 24 is still in a turbulent state, its pressure response when passing through abrupt changes in cross-section will exhibit random fluctuation characteristics, making it impossible to form a stable local negative pressure zone.

[0053] It should be noted that "expansion volume" refers to the internal space volume of the first cavity 23 being greater than the characteristic volume corresponding to the equivalent flow cross-section of its upstream air inlet 22 and its downstream airflow channels. The physical purpose of this configuration is that when the external low-temperature airflow enters the first cavity 23 through the air inlet 22, the airflow velocity decreases significantly due to the sudden expansion of the flow space. The large-scale turbulent vortices of the airflow gradually dissipate within this expansion space due to the lack of boundary constraints to maintain their rotational motion. The flow direction of the airflow tends to be homogenized, and finally a laminar flow state advancing along a preset direction is formed.

[0054] Furthermore, a second cavity 24 is formed inside the wall substrate 21, and the second cavity 24 has a second volume. The second cavity 24 is connected downstream of the first cavity 23 through a first airflow channel. The equivalent flow cross-section of the second cavity 24 is configured to be smaller than that of the first cavity 23. Due to the sudden reduction in the equivalent flow cross-section, the airflow after lamination in the first cavity 23 will inevitably increase in velocity when entering the second cavity 24 according to the continuity equation, and its static pressure will inevitably decrease according to Bernoulli's principle, thereby forming a local negative pressure zone in the second cavity 24 that is lower than the internal environment of the electrical cabinet. The formation of this local negative pressure zone does not depend on any external mechanical work, but is determined by the abrupt change in cross-sectional geometry between the first cavity 23 and the second cavity 24.

[0055] It should be noted that the "equivalent flow cross-section" refers to the effective flow area perpendicular to the main airflow direction, after deducting the influence of the wall boundary layer. This feature defines the direction of cross-sectional change between the first cavity 23 and the second cavity 24 as "contraction"—that is, airflow flows from a large cross-sectional area to a small cross-sectional area. Based on the fluid continuity equation, when incompressible airflow flows through the cross-sectional contraction section, its velocity is inversely proportional to the flow cross-sectional area, that is, a decrease in cross-section necessarily leads to an increase in velocity; at the same time, according to Bernoulli's principle, an increase in velocity necessarily accompanies a decrease in static pressure. When the equivalent flow cross-section of the second cavity 24 is configured to be smaller than that of the first cavity 23, the above physical effects are superimposed within the second cavity 24, forming a negative pressure zone where the local static pressure is lower than the internal environmental pressure of the electrical cabinet.

[0056] Furthermore, a third cavity 25 with a third volume is provided inside the wall substrate 21. The third cavity 25 is connected to the downstream of the first cavity 23 through a second airflow channel. The second airflow channel and the first airflow channel are arranged in parallel branches on the downstream side of the first cavity 23. When the airflow after lamination in the first cavity 23 reaches the outlet end of the first cavity 23, it is naturally divided into two parts according to the flow resistance characteristics of the two branch channels—one part enters the third cavity 25 through the second airflow channel, and the other part enters the second cavity 24 through the first airflow channel. The two airflows are separated on the downstream side of the first cavity 23 and do not interfere with each other in the subsequent flow path.

[0057] It should be noted that the "parallel branch arrangement" refers to the second airflow channel and the first airflow channel sharing the same outlet area of ​​the first cavity 23 as a common upstream node. They each extend independently from this node to the third cavity 25 and the second cavity 24, without any series connection or intersection between them. The functional implication of this topology is that the airflow, after laminarization treatment in the first cavity 23, does not entirely flow into a single channel upon reaching the outlet end of the first cavity 23. Instead, based on the flow resistance characteristics of the two parallel branch channels, it is naturally divided into two parts in a certain proportion—one part enters the third cavity 25 via the second airflow channel, and the other part enters the second cavity 24 via the first airflow channel.

[0058] In one specific implementation, such as Figure 9As shown, a feedback channel 241 is also provided inside the wall substrate 21. One end of the feedback channel 241 is connected to the second cavity 24, and the other end is connected to the internal environment of the electrical cabinet. Since a local negative pressure zone is formed in the second cavity 24, a pressure difference is generated between the local negative pressure zone and the internal environment of the electrical cabinet. This pressure difference drives the airflow in the internal environment of the electrical cabinet to flow into the second cavity 24 through the feedback channel 241. This process realizes the active entrainment of the airflow inside the electrical cabinet—the hot air that was originally stagnant inside the electrical cabinet is continuously drawn into the second cavity 24 and merges with the low-temperature airflow from the first cavity 23 in the second cavity 24.

[0059] Based on the solution provided in the aforementioned embodiments, the airflow organization path of this multi-stage heat dissipation structure can be summarized as follows: Low-temperature external airflow enters the first chamber 23 through the inlet 22 for rectification and voltage stabilization. Then, it splits at the outlet of the first chamber 23, with one path entering the third chamber 25 for heat exchange and the other entering the second chamber 24 to generate local negative pressure. The local negative pressure in the second chamber 24 acts on the internal environment of the electrical cabinet via the feedback channel 241, continuously drawing in hot air from inside the cabinet. The drawn-in hot air mixes with the low-temperature airflow in the second chamber 24 and is then fed back into the electrical cabinet via a subsequent processing path. All the aforementioned chambers and channels are integrated within the wall substrate 21, eliminating the need for additional installation space inside the electrical cabinet.

[0060] Based on the solutions provided in the foregoing embodiments, those skilled in the art may notice that this multi-stage heat dissipation structure does not include an intake fan, blower, or any other form of external mechanical power source. This raises questions: Without an active power source, can the ambient low-temperature airflow smoothly enter the first chamber 23 through the intake port 22, and can this intake behavior be sustained continuously? Therefore, this embodiment needs to clarify—the intake mechanism relied upon in this embodiment is not based on positive pressure pushing from the air source side, but on negative pressure suction from the load side; its physical essence is passive air replenishment driven by pressure difference. Please refer to... Figure 10 The intake process is implemented in two stages: the start-up stage and the steady-state operation stage.

[0061] First, the start-up phase. The electrical components within the internal environment generate heat dissipation, which gradually increases the air temperature within the enclosed space of the cabinet, correspondingly decreasing the gas density. Given that the internal environment is not completely sealed (the presence of the air inlet 22 and the exhaust structure 3 ensures a connection between the cabinet and the outside atmosphere), the hot air inside the cabinet generates upward thermal buoyancy due to the decreased density, and is discharged to the outside atmosphere via the exhaust structure 3. This discharge reduces the total amount of gas inside the cabinet, resulting in a slightly negative static pressure relative to the outside atmosphere. This slight negative pressure serves as the initial driving force, transmitted through the second working chamber 12 and feedback channel 241 to the second chamber 24, then through the first airflow channel to the first chamber 23, and finally to the air inlet 22, driving the low-temperature airflow from the outside into the first chamber 23 through the air inlet 22. The air intake driving force in this start-up phase is entirely provided by natural convection caused by thermal buoyancy, without involving any external mechanical work.

[0062] Secondly, the steady-state operation phase. When the airflow established during the startup phase begins to flow through the abrupt change in cross-section between the first cavity 23 and the second cavity 24, according to the fluid continuity equation and Bernoulli's principle, the airflow velocity increases and the static pressure decreases at the point where the equivalent flow cross-section suddenly contracts, thus forming a local negative pressure zone in the second cavity 24 that is lower than the static pressure of the internal environment of the electrical cabinet. The formation of this local negative pressure zone means that the static pressure of the second cavity 24 is lower than that of the internal environment of the electrical cabinet. The feedback channel 241 directs this pressure difference to the internal environment of the electrical cabinet, continuously drawing in hot air from inside the cabinet. This suction further reduces the gas inside the cabinet, maintaining the pressure inside the cabinet at a state lower than the external atmospheric pressure, thereby forming a continuous pressure gradient through the air inlet 22—the external atmospheric pressure is higher than the internal pressure of the first cavity 23, and this pressure difference continuously drives the external airflow into the first cavity 23 through the air inlet 22.

[0063] Therefore, the air intake process of this device constitutes a complete self-sustaining causal chain: the narrowing structure at the second chamber 24 generates a local negative pressure, which draws in hot air from the cabinet through the feedback channel 241, reducing the pressure inside the cabinet. This creates a pressure difference between the outside atmosphere and the first chamber 23, allowing outside airflow to enter through the air inlet 22. The incoming airflow then flows through the narrowing structure, continuing to maintain the local negative pressure. The initial triggering condition for this cycle is only the natural convection caused by heat dissipation inside the electrical cabinet. Thereafter, it is maintained by the hydrodynamic effect of the narrowing structure itself, without any active control or external energy input.

[0064] It is worth noting that in actual engineering implementation, if the electrical cabinet is cold-started (i.e., sufficient thermal buoyancy has not yet formed inside the cabinet), those skilled in the art can adopt the following auxiliary measures: orient the air inlet 22 towards the windward direction, using the ambient natural wind pressure to assist in guiding the initial airflow into the first chamber 23; or use the air pressure fluctuations caused by the opening and closing of the cabinet door to trigger a small amount of airflow in the initial stage. The above measures are only auxiliary means for cold-start. Once a stable flow is established in the second chamber 24, the diameter reduction effect begins to take effect, the negative pressure generation mechanism automatically starts and enters steady-state operation. The above auxiliary measures are not necessary technical features for achieving the air intake function in this embodiment, nor do they affect the integrity of the air intake achieved by the above pressure difference drive mechanism in the absence of an active power source.

[0065] It is worth noting that the equivalent flow cross-sections of the first cavity 23, the second cavity 24, and the third cavity 25 in this embodiment are not solely determined by their geometric cross-sectional areas; the effects of the wall boundary layer and local resistance losses must also be considered. In actual engineering implementation, those skilled in the art can determine the specific values ​​of the equivalent flow cross-sections of each cavity through computational fluid dynamics simulation or experimental measurement to meet the configuration requirements of the aforementioned cross-sectional size relationship. Furthermore, the volume configuration schemes of the first cavity 23, the second cavity 24, and the third cavity 25 are not unique; those skilled in the art can use various volume gradient configuration schemes described later as specific implementation methods for the volume relationship in this embodiment.

[0066] Based on the solutions provided in the foregoing embodiments, the volume ratio of the first cavity 23, the second cavity 24, and the third cavity 25 in the multi-stage heat dissipation structure has not been specifically limited. This section further provides various volume configuration schemes for the above three cavities, so that those skilled in the art can select an appropriate volume ratio relationship according to the actual application scenario to achieve different aerodynamic performance. In this embodiment, the volume dimensions of the first cavity 23, the second cavity 24, and the third cavity 25 are configured as one of the following schemes, such as... Figure 7-9 As shown.

[0067] In one specific implementation, the volume of the first cavity 23 is greater than the volume of either the second cavity 24 or the third cavity 25. The purpose of this configuration is that the first cavity 23, as the inlet chamber for external airflow, must provide sufficient space to accommodate the external airflow entering through the inlet 22, and allow the airflow to fully dissipate its turbulent pulsations within this expanded space. When the volume of the first cavity 23 is significantly larger than any downstream cavity, the velocity of the external airflow decreases dramatically after entering the first cavity 23. The large-scale vortex structure of the airflow gradually weakens due to the lack of boundary constraints to maintain its rotational motion, and the airflow direction tends to become homogenized, ultimately forming a laminar flow state advancing along a predetermined direction. The quality of establishing this laminar flow state directly affects the stability of negative pressure generation at the downstream narrowing section—if the volume of the first cavity 23 is insufficient to allow the airflow to fully develop into a laminar flow state, the airflow entering the second cavity 24 will still retain a high degree of turbulence, and its pressure response at the abrupt change in cross-section will exhibit random pulsation characteristics, failing to form a stable local negative pressure zone with a definite pressure value. This solution is suitable for applications where the internal heat load of the electrical cabinet is relatively low and the required airflow is small. In such scenarios, the first chamber 23 only needs to ensure that its volume is sufficient to complete the laminar flow treatment of the airflow, and the volume relationship between the second chamber 24 and the third chamber 25 does not constitute a dominant factor in the overall performance of the system.

[0068] Another specific implementation is that the volume of the first cavity 23 is larger than the volume of the second cavity 24, and the volume of the second cavity 24 is larger than the volume of the third cavity 25. This configuration mainly creates a complete volume gradient that gradually decreases from the first cavity 23 to the third cavity 25. The physical significance of this volume gradient configuration is that it forms a gradually decreasing spatial sequence along the main airflow direction within the multi-stage heat dissipation structure. This spatial sequence corresponds to the functional positioning of each cavity—the first cavity 23, as the largest volume cavity, undertakes the functions of air intake and pressure stabilization; the second cavity 24, as an intermediate volume cavity, undertakes the functions of diameter reduction, throttling, and negative pressure generation; and the third cavity 25, as the smallest volume cavity, undertakes the function of heat and moisture exchange.

[0069] Specifically, the first chamber 23 has the largest volume, used to accommodate external airflow and complete laminarization. Its large volume allows the airflow to achieve sufficient flow development length within this region, ensuring that the airflow entering the downstream has a uniform velocity profile. The second chamber 24 has a volume between the first chamber 23 and the third chamber 25. Its equivalent flow cross-section is configured to be smaller than that of the first chamber 23. Here, the airflow accelerates and depressurizes due to the abrupt change in cross-section, forming a local negative pressure zone. The intermediate volume configuration of the second chamber 24 provides sufficient space to accommodate the inflow of entrained airflow from the feedback channel 241 without weakening the negative pressure intensity at the narrowing point due to excessive volume. The third chamber 25 has the smallest volume, where the airflow has the highest velocity. This is beneficial for enhancing the convective heat transfer coefficient between the airflow and the heat and moisture exchange medium. At the same time, the smaller chamber volume helps maintain the penetration velocity of the airflow when passing through the microchannel plate 253 and the porous sieve substrate 254, avoiding the formation of backflow dead zones within the chamber.

[0070] Furthermore, this progressively decreasing volumetric gradient configuration creates a pressure gradient field within the electrical cabinet that decreases from the first chamber 23 to the third chamber 25. The physical meaning of this pressure gradient field is that, along the airflow direction, the static pressure in each chamber exhibits a decreasing trend, consistent with the main airflow direction. This helps suppress backflow of airflow against the pressure gradient between chambers, improving the overall efficiency of the pneumatic circulation. Specifically, the first chamber 23 maintains a relatively high pressure level due to the connection of the air inlet 22 to the outside atmosphere; the second chamber 24 is at a local minimum pressure due to the narrowing effect; and the third chamber 25 is at an intermediate pressure level due to the flow resistance of the airflow passing through the microchannel plate 253 and the porous sieve substrate 254. This pressure distribution pattern allows the airflow in the first chamber 23 to naturally flow towards the second chamber 24 and the third chamber 25 under pressure differential drive, while the local minimum pressure in the second chamber 24 continuously draws in hot air from inside the electrical cabinet through the feedback channel 241, forming a directional airflow circulation.

[0071] It is understood that Scheme 1 and Scheme 2 are two parallel volume configuration methods, and they are not mutually exclusive substitutes. Specifically, Scheme 1 is the basic configuration scheme, which only requires the first cavity 23 to have a maximum volume to meet the basic requirements of laminar flow treatment; Scheme 2 is a better configuration scheme, which further limits the volume relationship between the second cavity 24 and the third cavity 25 based on Scheme 1, so as to form a complete volume gradient and establish a pressure gradient field. Those skilled in the art can choose the appropriate one between Scheme 1 and Scheme 2 to implement according to the airflow requirements, heat load, and spatial layout constraints in the actual application scenario. Under the condition that the spatial layout allows, the progressively decreasing volume gradient of Scheme 2 has better aerodynamic performance than the single maximum volume limit of Scheme 1, but Scheme 1 has greater layout flexibility in compact application scenarios.

[0072] It is worth noting that the specific volumes of the aforementioned chambers are not limited to absolute values ​​in this embodiment. This is because the internal dimensions of different electrical cabinets, the heating power of components, and the thermal tolerance of battery cells vary, resulting in corresponding changes in required airflow and pressure differences. Those skilled in the art, when implementing this embodiment, can determine the specific volume values ​​of each chamber using computational fluid dynamics simulation based on specific operating conditions, ensuring that the volume of the first chamber 23 meets the requirements of laminar flow treatment, and that the volume relationship between the second chamber 24 and the third chamber 25 conforms to the requirements of the selected scheme.

[0073] Based on the solutions provided in the foregoing embodiments, those skilled in the art can also make adaptive adjustments to the two solutions without departing from the above-described volume configuration principle—for example, proportionally reducing or enlarging the actual dimensions of each chamber according to the thickness limitation of the electrical cabinet wall substrate. As long as the above-described volume size relationship remains unchanged, it falls within the scope of the implementation methods covered by this embodiment. Furthermore, the correspondence between the chamber volume and pneumatic function embodied in the above two volume configuration solutions also applies to the specific implementation methods described below. In the embodiments involving the first chamber 23, the second chamber 24, and the third chamber 25 described later, unless otherwise stated, the volume configuration of each chamber can be determined with reference to Scheme 1 or Scheme 2 in this section.

[0074] Based on the scheme provided in the aforementioned embodiments, the airflow after laminarization treatment in the first chamber 23 is split into two paths downstream of the first chamber 23—one path enters the second chamber 24 via the first airflow channel, and the other path enters the third chamber 25 via the second airflow channel. The two airflow paths perform different physical functions: the airflow entering the second chamber 24 is mainly used to generate local negative pressure through the narrowing effect, and its required airflow is sufficient to meet the negative pressure suction requirements; the airflow entering the third chamber 25 is mainly used for heat exchange and humidity transfer with the heat and moisture exchange medium, and its required airflow is sufficient to bear the heat exchange load. This section further provides the configuration relationship of the equivalent flow area between the aforementioned first and second airflow channels.

[0075] In this embodiment, the equivalent flow area of ​​the second airflow channel is larger than that of the first airflow channel. The physical basis for this configuration is that, under the same upstream pressure conditions, the mass flow rate passing through the two parallel branch channels is inversely proportional to their respective flow resistance. When the equivalent flow area of ​​the second airflow channel is larger than that of the first airflow channel, the flow resistance of the second airflow channel is relatively small. Therefore, the mass flow rate of the airflow entering the third cavity 25 through the second airflow channel is greater than that of the airflow entering the second cavity 24 through the first airflow channel. The rationality of the above mass flow rate distribution relationship is that the third cavity 25 undertakes the function of heat and moisture exchange. The heat and moisture exchange medium set inside it (see Embodiment 2 below for specific structure) generates flow resistance to the airflow. At the same time, the heat and moisture exchange process requires sufficient airflow mass flow rate to carry the heat generated by the heating element and transfer it to the exhaust path. The second cavity 24 undertakes the function of negative pressure generation. Its physical effect of forming a local negative pressure zone through abrupt change in cross-sectional area mainly depends on the airflow velocity rather than the mass flow rate. Under the condition that the equivalent flow cross section is fixed, the airflow mass flow rate required to maintain the negative pressure zone is relatively small. Therefore, allocating a larger portion of the airflow to the third chamber 25 and a smaller portion to the second chamber 24 is a reasonable configuration that takes into account both types of functional requirements.

[0076] Furthermore, the actual effect of this differential configuration of equivalent flow area in a multi-stage heat dissipation structure can be explained with reference to the accompanying drawings. For example... Figure 7-9 As shown, the second airflow channel extends from the outlet of the first cavity 23 to the inlet of the third cavity 25, while the first airflow channel extends from another location at the outlet of the first cavity 23 to the inlet of the second cavity 24. As can be seen from the attached figures, the cross-sectional dimension of the second airflow channel is larger than that of the first airflow channel; this difference in cross-sectional dimension reflects the size relationship of the equivalent flow area described in this embodiment. Through this configuration of cross-sectional dimension difference, the laminar airflow exiting the first cavity 23 naturally flows into the second airflow channel in a larger proportion and into the first airflow channel in a smaller proportion at the flow splitting node, without the need for any active control elements or flow splitting adjustment devices.

[0077] It is understandable that "equivalent flow area" is not simply equivalent to the geometric cross-sectional area of ​​the channel. In actual implementation, the cross-sectional shapes of the first and second airflow channels may differ due to the internal space constraints of the wall substrate 21—for example, the first airflow channel may have a circular cross-section, the second airflow channel may have a rectangular cross-section, or both may be rectangular cross-sections but with different size ratios. When the channel cross-sectional shapes differ, a direct comparison of the geometric cross-sectional areas cannot accurately reflect their airflow capacity. Therefore, this embodiment uses "equivalent flow area" as a comparison benchmark, meaning that under the same upstream pressure conditions and the same channel length, the flow resistance of the channel under test is converted into the cross-sectional area value of a circular straight pipe of the same length. This equivalent value can be determined through fluid dynamics calculations or experimental measurements. Those skilled in the art can determine whether the equivalent flow areas of the first and second airflow channels satisfy the size relationship defined in this embodiment without any creative effort, based on the above definition.

[0078] Preferably, the ratio of the equivalent flow area of ​​the second airflow channel to the equivalent flow area of ​​the first airflow channel ranges from 2:1 to 5:1. This ratio range is selected based on the following: when the ratio is below 2:1, the difference in flow area between the two channels is insufficient to generate a significant difference in mass flow rate. The actual airflow rate obtained by the second chamber 24 may be higher than the airflow rate required to generate its reduced negative pressure, resulting in some airflow energy being wasted on unnecessary negative pressure enhancement. Meanwhile, the airflow rate obtained by the third chamber 25 is insufficient, reducing the heat and moisture exchange effect. When the ratio is above 5:1, the flow area of ​​the second airflow channel is too large, and the flow area of ​​the first airflow channel is too small. This may increase the total flow resistance at the outlet of the first chamber 23, leading to an overall decrease in the intake volume at the inlet 22. Furthermore, the insufficient airflow obtained by the second chamber 24 may not be enough to maintain the stable existence of the local negative pressure zone. Within the above ratio range, the system's airflow distribution efficiency and heat dissipation performance are in a relatively optimal balance. Of course, this ratio range is not an absolute limitation. Those skilled in the art can select an appropriate specific ratio outside the above range based on the actual heat load and spatial layout conditions of the electrical cabinet, which still falls within the scope of the implementation methods covered by this embodiment.

[0079] It should be noted that the relationship between the equivalent flow area of ​​the second airflow channel and the equivalent flow area of ​​the first airflow channel as defined in this embodiment is a geometric configuration requirement of a different dimension from the relationship between the chamber volume size defined in the second part of the aforementioned embodiment. The former involves the flow cross-sectional area of ​​the connecting channel, which determines the airflow distribution ratio; the latter involves the volume size of each chamber itself, which determines the flow development state and pressure distribution pattern of the airflow within the chamber. The two are independent but synergistic—the proportional relationship of the channel cross-sectional area controls the airflow rate entering each chamber, and the relationship between the chamber volumes controls the flow state and pressure level within each chamber, together constituting a complete geometric configuration system of a multi-stage heat dissipation structure.

[0080] Based on the solutions provided in the foregoing embodiments, those skilled in the art will also understand that the aforementioned equivalent flow area relationship is not achieved solely by changing the geometric dimensions of the channels. For example, an alternative implementation is to increase the flow resistance by adding flow-blocking elements (such as orifice plates, porous flow restrictors, etc.) within the first airflow channel, under the condition of the same cross-sectional dimensions. This results in the equivalent flow area of ​​the second airflow channel being relatively larger than that of the first airflow channel, thus achieving the same airflow mass flow distribution effect described in this embodiment. The aforementioned alternative methods also fall within the scope of this embodiment.

[0081] Example 2. Based on the solution provided in the previous example, the portion of the airflow that enters the third chamber 25 via the second airflow channel after fluidization treatment in the first chamber 23 undertakes the heat and moisture exchange function. In the actual operating conditions of the battery energy storage system, the water vapor content in the air inside the electrical cabinet may fluctuate due to changes in ambient humidity. When high humidity air flows over a cooler wall surface, condensation may occur. Condensation droplets adhering to the surface of electrical components may lead to decreased insulation performance or short circuit risk. At the same time, electronic components and battery cells inside the electrical cabinet may release trace amounts of volatile organic gases or by-reaction products during operation. If these substances continue to accumulate inside the cabinet, they may adversely affect the chemical stability of the battery cells. Therefore, relying solely on the single function of airflow convection heat exchange is insufficient to meet the above-mentioned diversified operating conditions. A specific configuration scheme for the heat and moisture exchange medium with humidity control and gas handling capabilities is needed.

[0082] This embodiment, based on the multi-stage heat dissipation structure provided in Embodiment 1, further defines the specific construction of the heat and moisture exchange medium inside the third cavity 25. For example... Figure 7-9 As shown, a heat exchange chamber 251 is provided inside the third chamber 25, and a heat and moisture exchange medium is disposed inside the heat exchange chamber 251, and a guide plate 252 for constraining the airflow direction is provided. The heat and moisture exchange medium includes microchannel plates 253 stacked together and porous sieve substrate 254.

[0083] Specifically, the microchannel plate 253 is constructed as a plate-like component with multiple microchannels extending along the airflow direction, with adjacent channels separated by thin walls. The equivalent diameter of each microchannel is configured on the sub-millimeter scale. When airflow passes through the microchannel plate 253, because the channel size is much smaller than the characteristic scale of the macroscopic flow channel, the airflow forms a laminar flow state with a high convective heat transfer coefficient within the channel. The heat exchange area between the airflow and the channel wall is significantly increased due to the high specific surface area of ​​the microchannel, thereby achieving efficient heat transfer within a limited spatial volume.

[0084] Furthermore, the porous sieve substrate 254 is constructed as a plate-like member with a three-dimensional interconnected pore structure, the porosity of which is configured to allow airflow to pass through with low resistance while providing sufficient solid-gas contact area. The pore structure of the porous sieve substrate 254 also functions to intercept suspended particulate matter entrained in the airflow, thereby purifying the airflow.

[0085] Furthermore, the microchannel plate 253 and the porous sieve substrate 254 are arranged in a stacked manner inside the third cavity 25. The stacking order can be either the microchannel plate 253 on the upstream side and the porous sieve substrate 254 on the downstream side, or vice versa. Both stacking orders can achieve their respective functions and cooperate with each other. During the airflow's passage through this stacked structure, the airflow sequentially or alternately experiences enhanced convection heat transfer within the microchannels and diffusion heat transfer and particle interception within the porous medium. These two different heat exchange mechanisms work together within the same compact space to jointly regulate the airflow temperature and achieve purification.

[0086] It should be noted that at least one of the microchannel plate 253 and the porous sieve substrate 254 is coated with a phase change material coating. The phase change material is configured to have solid-liquid phase change characteristics within the normal operating temperature range of the electrical cabinet. When the temperature of the airflow flowing through the third chamber 25 is higher than the phase change temperature, the phase change material absorbs heat and changes from solid to liquid. This phase change process is accompanied by a large amount of latent heat absorption, thereby achieving efficient absorption of heat from the airflow under essentially constant temperature conditions. When the airflow temperature is lower than the phase change temperature, the phase change material releases heat and changes from liquid to solid. This heat release process can preheat and compensate for the subcooled airflow, preventing the low-temperature airflow from directly entering the electrical cabinet and causing thermal shock to the battery cells. The presence of the phase change material coating enables the third chamber 25 to not only perform steady-state convective heat transfer but also to have a passive buffering capability against temperature fluctuations.

[0087] In a preferred embodiment, the phase change material coating includes two types: a hydrophilic coating phase change material and a catalytic decomposition coating phase change material. The hydrophilic coating phase change material is disposed on the surface of the porous sieve substrate 254. Its hydrophilic properties cause a water molecule adsorption film to form on the surface of the porous sieve substrate 254. When water vapor molecules in the airflow come into contact with the adsorption film, they are captured and undergo phase change condensation. The latent heat released by condensation is absorbed by the phase change material, thereby achieving dehumidification of the airflow. Simultaneously, the captured water participates in latent heat transfer during the endothermic melting process of the phase change material, transferring heat from the airflow to the interior of the phase change material in the form of latent heat of phase change. The catalytic decomposition coating phase change material is disposed on the inner wall surface of the microchannel plate 253. Its catalytically active components have higher molecular mobility and reactivity in the molten state of the phase change material, enabling the catalytic decomposition of trace amounts of volatile organic compounds or battery by-reaction products carried in the airflow into harmless small molecules, thereby achieving purification of the airflow.

[0088] It is worth noting that the phase change material coating is not limited to being applied to the surface of the microchannel plate 253 or the porous sieve substrate 254. In alternative embodiments, the phase change material can be filled into the microchannels of the microchannel plate 253 in the form of adsorption on a porous carrier, or it can be disposed in the interstitial layer between the microchannel plate 253 and the porous sieve substrate 254 in the form of a particle-filled bed. The above alternative methods can also achieve the functions of phase change heat storage and temperature buffering, and those skilled in the art can select an appropriate phase change material immobilization method according to the actual manufacturing process conditions.

[0089] An optional extended embodiment involves configuring the microchannel plate 253 as a phase change material carrier with a hydrophilic coating and the porous sieve substrate 254 as a phase change material carrier with a catalytic decomposition coating, meaning the surface coating functions of the two media are interchangeable. The physical basis of this embodiment is that the hydrophilic coating needs to be in full contact with water vapor molecules in the gas flow; placing it on the surface of the porous sieve substrate 254 utilizes the high specific surface area of ​​the porous structure to increase the probability of water vapor capture. The catalytic decomposition coating needs to be in full contact with trace organic components in the gas flow; placing it on the inner wall of the microchannel plate 253 utilizes the high flow rate conditions within the microchannel to enhance molecular diffusion and mass transfer efficiency. The placement of the two functional coatings can be adjusted according to specific operating conditions, and both are embodiments covered in this example.

[0090] In another optional extended embodiment, the heat and moisture exchange medium is not limited to the stacked combination of microchannel plate 253 and porous sieve substrate 254. For example, one alternative is to impregnate a foamed metal matrix with phase change material and then directly fill it into the third cavity 25. The three-dimensional interconnected pore structure of the foamed metal simultaneously serves as an airflow channel and a phase change material carrier. Another alternative is to mix phase change material microcapsules and porous ceramic particles and fill them into the third cavity 25. The phase change material microcapsules provide latent heat absorption capacity, while the porous ceramic particles provide airflow uniformity and heat exchange area. The above alternatives all fall within the scope of the specific implementation of the heat and moisture exchange medium covered in this embodiment.

[0091] Furthermore, when the multi-stage heat dissipation structure is installed on the wall of the appliance cabinet 1, such as... Figure 9 As shown, the inlet end of the heat exchange chamber 251 is connected to the second airflow channel, and the outlet end is connected to the internal space of the electrical cabinet via the feed outlet. After the airflow passes through the stacked structure of the microchannel plate 253 and the porous sieve substrate 254, its temperature is regulated, its humidity is controlled, and the concentration of harmful components is reduced. The treated clean temperature-regulating airflow is sent into the internal space of the electrical cabinet via the feed outlet, thereby achieving the control of the thermal and humidity state of the cabinet environment.

[0092] It should be noted that the specific material selection of the phase change material described in this embodiment is not limited to a certain specific material. Those skilled in the art can select from known phase change material systems based on the actual operating temperature range of the electrical cabinet. For example, any one of organic phase change materials (paraffins, fatty acids) or inorganic phase change materials (hydrated salts) can be selected, as long as its phase change temperature is within or near the normal operating temperature range of the electrical cabinet, the temperature buffering and latent heat transfer functions described in this embodiment can be realized.

[0093] Based on the solutions provided in the foregoing embodiments, those skilled in the art will understand that the solutions in Embodiment 1 and its various parts focus on the chamber topology and macroscopic configuration of the multi-stage heat dissipation structure, while the solution in this embodiment focuses on the specific construction and functional division of the heat and moisture exchange medium inside the third cavity 25. The above content belongs to different levels of specific implementation methods under the same inventive concept and does not constitute exclusive limitations on each other. When implementing this embodiment, the volume configuration of the third cavity 25 can be determined with reference to Solution 1 or Solution 2 described in Part 2 of Embodiment 1, and the equivalent flow area relationship between the first airflow channel and the second airflow channel can be determined with reference to the configuration described in Part 3 of Embodiment 1. Furthermore, the features of the above embodiments are physically compatible with each other and can be combined and implemented in the same multi-stage heat dissipation structure. Example 3. Based on the scheme provided in the previous examples, the airflow treated by the heat and moisture exchange medium inside the third chamber 25 is returned to the internal space of the electrical cabinet via the feed outlet, while the local negative pressure zone formed at the second chamber 24 draws in hot air from inside the cabinet through the opening of the feedback channel 241. Without spatial optimization, there is a potential risk of airflow short-circuiting between the treated low-temperature airflow discharged through the feed outlet and the hot air drawn into the cabinet through the feedback channel opening—that is, the treated low-temperature airflow is directly drawn back to the second chamber 24 by the feedback channel opening before it has fully diffused to the heat source area inside the cabinet, forming an ineffective local circulation. This phenomenon will cause the hot air deep inside the cabinet (especially at the bottom of the battery compartment) to be unable to be effectively replaced for a long time, resulting in the continuous existence of local hot spots. This example is proposed to optimize the spatial path relationship between the treated airflow and the hot air to be drawn in.

[0094] In this embodiment, as Figure 7-9 As shown, the opening of the feedback channel 241 within the electrical cabinet is positioned below the feed outlet of the third chamber 25, which supplies airflow into the electrical cabinet. This spatial configuration is based on the spatial synergy between thermal buoyancy and the difference in airflow density. The airflow, after undergoing heat and moisture exchange in the third chamber 25, absorbs heat generated by the heating components during the heat exchange process, resulting in a temperature higher than the average temperature of the electrical cabinet's interior environment and a corresponding decrease in density. Therefore, it exhibits a natural upward thermal buoyancy tendency.

[0095] For example, when the feed outlet is set at a high position, the treated airflow, after being discharged from the high position, tends to move upward in the same direction as the discharge direction of the feed outlet. This facilitates the diffusion of the treated hot airflow along the upper space of the cabinet and the formation of a top-down thermal convection circulation. Simultaneously, the local negative pressure zone at the second chamber 24 acts on the lower opening inside the cabinet via the feedback channel 241, continuously drawing in air from the lower space of the cabinet. Because the density of hot air inside the cabinet is lower than that of cold air, hot air tends to accumulate in the upper region of the cabinet, while air with a relatively lower temperature and higher density settles in the lower region of the cabinet and is preferentially drawn out through the lower opening of the feedback channel 241.

[0096] This explains why the high-level arrangement of the feed outlet and the low-level arrangement of the feedback channel opening together form a directional airflow loop along the height of the cabinet space. The treated airflow, fed in from the high level, gradually sinks, exchanges heat with the heat-generating components and battery cells in the flow path, absorbs heat, and rises in temperature. Then, under the action of thermal buoyancy, it rises and is drawn back into the circulation system through the feedback channel opening. This airflow loop covers the entire height range of the cabinet space, effectively avoiding airflow short-circuiting and allowing hot air deep inside the cabinet (including the bottom area of ​​the battery compartment) to be continuously entrained and replaced.

[0097] Furthermore, such as Figure 8 As shown, on the wall surface of the wall base 21 facing the interior space of the electrical cabinet, the feed outlet is located in the upper region of the wall surface, and the opening of the feedback channel 241 is located in the lower region of the wall surface. The longitudinal distance between the two is at least three times the equivalent diameter of the feed outlet or the feedback channel opening itself. This spacing configuration ensures that the treated airflow has a certain free jet diffusion space after discharge and will not be immediately sucked into the feedback channel opening.

[0098] In a preferred embodiment, a guide structure may be provided at the feed outlet to allow the treated airflow to exit horizontally or diagonally downward toward the interior space of the electrical cabinet, thereby promoting the diffusion and coverage of the airflow into the depth of the cabinet. A protective mesh or grille structure may be provided at the opening of the feedback channel 241 to prevent large debris or cables from being sucked into the feedback channel 241.

[0099] In an optional extended embodiment, when the electrical cabinet is equipped with shelves 14 to accommodate battery cells in layers, the feed outlet can be located in the upper region of the shelves, and the opening of the feedback channel 241 can be located in the lower region of the shelves. This configuration allows airflow to travel from top to bottom between the shelves 14, ensuring that each layer of battery cells is covered by the airflow, further improving the uniformity of heat dissipation.

[0100] In another optional extended embodiment, for electrical cabinets with greater height, multiple feed outlets and multiple feedback channel openings can be spaced apart along the height direction on the wall base 21, but it must be ensured that the position of any feed outlet is higher than the position of its corresponding feedback channel opening. This multi-point arrangement can enhance the coverage of airflow circulation without affecting the principle of height relationship. The above-mentioned extended embodiments are all within the scope of this embodiment.

[0101] Based on the solutions provided in the foregoing embodiments, it is worth noting that the "opening position" defined in this embodiment refers to the coordinate position of the geometric center or equivalent flow center of the opening in the height direction of the internal space of the electrical cabinet, rather than the position of a specific point on the opening boundary. In engineering implementation, when the vertical projections of the feed outlet and the feedback channel opening overlap, the equivalent flow center heights of the two should be compared to ensure that the center height of the feed outlet is higher than the center height of the feedback channel opening. The method for determining this equivalent center height is well known to those skilled in the art and will not be elaborated here.

[0102] Based on the solution provided in the aforementioned embodiments, the multi-stage heat dissipation structure introduces low-temperature airflow from the outside into the electrical cabinet through the air intake structure 2. After heat and moisture exchange, the airflow is fed into the cabinet space to participate in thermal circulation. This embodiment provides an exhaust structure that does not rely on an active power source and can recover and utilize the heat of the exhaust airflow.

[0103] In this embodiment, the exhaust structure 3 includes a support base 31. The support base 31 is integrated into the wall of the electrical cabinet and is arranged opposite to the wall base 21 described in the previous embodiment. Specifically, if the wall base 21 serves as the air intake side wall of the electrical cabinet (such as the front door), then the support base 31 serves as the air outlet side wall of the electrical cabinet (such as the rear wall or rear door); and vice versa. The support base 31 and the wall base 21 together define the airflow inlet side and airflow outlet side of the internal space of the electrical cabinet, so that the external airflow flows in an orderly manner in a single direction: "air intake structure 2 → internal space of electrical cabinet → exhaust structure 3".

[0104] Specifically, a second mesh area 32 is provided on the support base 31. The second mesh area 32 is configured to have multiple vent holes penetrating the wall of the support base 31. The total flow area of ​​the vent holes is configured to be no less than the flow area of ​​the air inlet 22 in the air inlet structure 2, to ensure that the flow resistance on the exhaust side is not higher than that on the air inlet side, thereby avoiding the suppression of air intake due to excessive exhaust resistance causing the pressure inside the cabinet to rise. The aperture of the vent holes is configured to allow airflow to be discharged smoothly while intercepting large debris (such as leaves, paper scraps, insects, etc.) from the external environment from entering the cabinet. In one specific embodiment, the vent holes of the second mesh area 32 are arranged in an array, and the equivalent diameter of each vent hole ranges from 3 mm to 10 mm.

[0105] Furthermore, a finned plate 33 is also provided on the support base 31. The finned plate 33 is constructed as a plate-shaped extension protruding outward from the surface of the support base 31, having a large surface area and a small thickness, and is made of a metal material with good thermal conductivity (such as aluminum alloy or copper alloy). The finned plate 33 is positioned corresponding to the peripheral area of ​​the second mesh area 32 or the interval area between the vents penetrating the second mesh area 32. When the airflow inside the electrical cabinet is discharged to the outside atmosphere through the second mesh area 32, part of the heat carried by the airflow is transferred to the surface of the finned plate 33 through convection heat transfer. The finned plate 33 uses its large heat dissipation area to further dissipate the heat into the outside air, thereby achieving heat recovery and dissipation of the discharged airflow during the exhaust process. The function of this heat recovery mechanism is that the temperature of the discharged airflow is reduced when it flows through the finned plate 33, thereby reducing the local heat island effect that may be caused by the direct discharge of high-temperature airflow into the outside environment. At the same time, the heat absorbed by the finned plate 33 is continuously dissipated through natural convection and radiation without increasing any additional energy consumption.

[0106] exist Figure 5 and Figure 6In the illustrated embodiment, the support base 31 of the exhaust structure 3 is constructed as the rear door or rear wall panel of the electrical cabinet. The second mesh area 32 is opened in the central region of the support base 31, and the fins 33 are disposed on the outer surface of the support base 31 (i.e., the side facing away from the interior space of the electrical cabinet). The advantage of this arrangement is that the fins 33 are located outside the cabinet, and their heat dissipation process does not release additional heat into the cabinet, avoiding secondary heat accumulation inside the cabinet. At the same time, the fins 33 are located on the outer surface of the cabinet, and can utilize natural airflow (such as wind) from the external environment to assist in heat dissipation, further improving heat dissipation efficiency.

[0107] An alternative implementation involves placing the fins 33 on the inner surface of the support base 31 (i.e., the side facing the interior space of the electrical cabinet). In this arrangement, the fins 33 are in direct contact with the hot air inside the cabinet. Heat is pre-dissipated through the conduction and convection of the fins 33 before the airflow is exhausted. The pre-cooled airflow is then discharged through the second mesh area 32. This method is suitable for applications with high ambient temperatures and limited heat dissipation conditions on the outer side of the fins 33.

[0108] Another alternative implementation involves not providing independent fins 33 on the support base 31, but instead extending the edges of the vents in the second mesh area 32 by flanging to form cylindrical or trumpet-shaped extension segments. Each extension segment serves the dual function of guiding airflow and increasing heat dissipation area. This method reduces the manufacturing and assembly processes of independent fin components and is suitable for cost-sensitive applications.

[0109] It is understood that the specific configuration of the exhaust structure 3 can be adapted to the installation environment, space constraints, and heat dissipation requirements of the electrical cabinet. Each alternative does not change the basic functional positioning of the exhaust structure 3 as an airflow exhaust channel, nor does it affect its cooperative relationship with the intake structure 2. Those skilled in the art, guided by the above embodiments, can select appropriate specific implementation methods based on actual working conditions, all of which fall within the scope of this embodiment.

[0110] Example 4. Based on the multi-stage heat dissipation structure provided in the foregoing embodiments, those skilled in the art can understand the physical configuration and connection relationships of the various components of this structure (wall base 21, first cavity 23, second cavity 24, third cavity 25, feedback channel 241, etc.). However, the foregoing embodiments mainly describe the layout and construction of each chamber from a structural perspective, without revealing the temporal logic and causal relationship of airflow organization between functional areas from a methodological perspective. Therefore, as Figure 1-2 As shown, this embodiment provides a heat-driven cycle method from a methodological perspective. This method can be implemented based on the multi-stage heat dissipation structure described in the foregoing embodiment, or it can be implemented based on other physical structures with the same functional area configuration.

[0111] In this embodiment, the method is used to dissipate heat from the internal environment of an electrical cabinet through gas circulation force. This gas circulation force originates from the thermal buoyancy caused by the temperature difference in the airflow and / or the pressure difference generated by a sudden change in the flow cross-section, and does not rely on an external mechanical power source. The method includes the following steps.

[0112] Step one involves allowing external low-temperature airflow to flow into a first functional region with a first equivalent flow cross-section. The expansion effect of the first functional region's volume eliminates the turbulent pulsating component in the low-temperature airflow, transforming it into a laminar flow state along a predetermined direction. This step corresponds to the process in the aforementioned embodiment where external low-temperature airflow enters the first cavity 23 through inlet 22 and completes its flow development within the expansion volume. After this step, the large-scale vortex structure inside the airflow is fully dissipated, the flow direction becomes more uniform, and a laminar flow with a uniform velocity profile is formed. The establishment of this laminar flow state provides stable incoming flow conditions for the subsequent negative pressure generation in the narrowing section—if the airflow entering the narrowing section retains a high degree of turbulence, its random velocity pulsations will cause continuous fluctuations in the pressure field downstream of the narrowing section, making it impossible to form a stable local negative pressure with a definite pressure value.

[0113] Step two involves guiding the low-temperature airflow through a second functional region with a second equivalent flow cross-section. This second equivalent flow cross-section is smaller than the first, increasing the airflow velocity and decreasing the static pressure within the second functional region, thus creating a localized negative pressure zone in the second functional region that is lower than the internal environmental pressure of the electrical cabinet. This step corresponds to the process in the aforementioned embodiment where laminar airflow enters the second cavity 24 through the first airflow channel and experiences accelerated pressure reduction due to a sudden change in cross-section. According to the fluid continuity equation and Bernoulli's principle, cross-sectional contraction increases the airflow velocity, which in turn increases the airflow pressure and decreases the static pressure. This decrease in static pressure can be adjusted by the cross-sectional ratio of the second functional region to the first functional region.

[0114] Step three: Using the pressure difference between the localized negative pressure zone and the internal environment of the electrical cabinet, the high-temperature airflow inside the electrical cabinet is drawn into the low-temperature airflow via the ejector channel connecting the second functional area and the internal environment of the electrical cabinet, forming a mixed airflow. This step corresponds to the function of the localized negative pressure zone formed at the second cavity 24 in the aforementioned embodiments, which draws in hot air from inside the electrical cabinet via the feedback channel 241. In this method, the "ejector channel" corresponds to the feedback channel 241 in the aforementioned structural embodiments.

[0115] Step four involves exchanging heat and moisture with the heat and moisture exchange medium located within the third functional area, and then returning the treated airflow to the internal environment of the electrical cabinet. This step corresponds to the process in the aforementioned embodiment where the mixed airflow enters the third cavity 25 and exchanges heat and moisture with the microchannel plate 253, the porous sieve substrate 254, and the phase change material coating. The term "return" refers to the treated airflow being redirected back to the internal space of the electrical cabinet, as opposed to the terms "exhaust" or "discharge"—the latter referring to the outside atmosphere, while "return" refers to the inside of the cabinet, indicating that the airflow still participates in the regulation of the internal thermal environment rather than being directly discarded.

[0116] Furthermore, in a preferred embodiment, before the low-temperature airflow enters the second functional region, the airflow first flows through a diversion channel located upstream of the third functional region. A portion of the airflow is guided into the third functional region to participate in heat exchange, while the other portion enters the second functional region to generate local negative pressure. The mass flow rate of the airflow entering the second functional region is less than the mass flow rate of the airflow entering the third functional region. The specific implementation of this diversion step can be seen in the equivalent flow area relationship between the second airflow channel and the first airflow channel arranged in parallel at the outlet end of the first cavity 23 in the aforementioned embodiment—by configuring the equivalent flow area of ​​the second airflow channel to be larger than that of the first airflow channel, most of the airflow enters the third cavity 25 for heat exchange, and a small portion enters the second cavity 24 to generate negative pressure. This diversion ratio ensures a reasonable distribution between the air volume required for negative pressure generation and the air volume required for heat exchange.

[0117] Furthermore, in Figure 2 In the schematic diagram shown, the first, second, and third functional areas are all integrated within the wall substrate of the electrical cabinet. After a mixed airflow is formed, the mixed airflow exchanges heat and moisture with the heat and moisture exchange medium located inside the third functional area, and the heat and moisture exchanged airflow is then returned to the internal environment through the return air outlet. The return air outlet is positioned higher than the connection between the ejector channel and the internal environment. The physical significance of this spatial relationship is that the airflow after heat and moisture exchange is relatively low in temperature and relatively high in density. After being sent into the cabinet from the high-level return air outlet, it naturally sinks. During its flow through the heating components and battery units, it absorbs heat, increasing in temperature and decreasing in density. Subsequently, under the action of thermal buoyancy, it rises to the upper region of the cabinet and is drawn back into the second cavity 24 through the low-level opening of the ejector channel (feedback channel 241). This spatial coordination of high-level feed-in and low-level suction creates a complete airflow coverage path from top to bottom within the cabinet, preventing the processed airflow from being directly drawn back by the ejector channel and forming an ineffective short-circuit loop.

[0118] It should be noted that in steps two and three, the low-temperature airflow does not entirely undergo diameter reduction and acceleration in the second functional area. Before entering the second functional area, the low-temperature airflow first flows through a diversion channel located upstream of the third functional area. A portion of the airflow is guided into the third functional area to participate in heat exchange, while the other portion enters the second functional area, generating local negative pressure. The mass flow rate of the airflow entering the second functional area is less than that entering the third functional area. This diversion step has substantial methodological significance—if the low-temperature airflow were entirely accelerated through diameter reduction in the second functional area, the system would only be equivalent to a simple diameter reduction nozzle structure. After the airflow is accelerated through diameter reduction, its pressure decreases, and its function is limited to forming a jet downstream of the diameter reduction section. Although this jet can produce a certain entrainment effect, the entrained airflow cannot undergo further heat and moisture treatment before being discharged or dissipated, and thus cannot form a circulating airflow that has a regulatory effect on the internal environment of the electrical cabinet. This method establishes a diversion channel upstream of the second functional area, allowing most of the airflow to directly enter the third functional area for heat and moisture exchange, while only a small portion enters the second functional area to generate local negative pressure. This separates the "negative pressure entrainment" and "heat and moisture exchange" functions into two parallel airflow paths, creating a functional division of aerodynamic topology. This diversion design ensures that the local negative pressure generated in the second functional area only needs to drive a sufficient flow rate of hot air within the entrainment chamber, while the main airflow required for heat and moisture exchange is independently handled by the third functional area. This avoids the conflict between "entrainment air" and "heat exchange air" competing for the same airflow in a single-diameter nozzle structure. The magnitude of this mass flow rate relationship is qualitatively defined in this method; those skilled in the art can adjust this relationship according to specific operating conditions by adjusting the equivalent flow area ratio of the diversion channel, without relying on specific numerical values.

[0119] It should be noted that in step four, especially after the mixed airflow is formed, the heat and moisture exchange treated airflow is returned to the internal environment through the return air outlet. The return air outlet is positioned higher than the connection between the ejector channel and the internal environment. This has three effects: First, after passing through the heat and moisture exchange medium in the third functional area, the temperature of the heat and moisture exchange treated airflow is lower than the original temperature of the entrained hot air inside the cabinet, and its density increases accordingly, resulting in a relatively cold state. When this relatively cold airflow is sent into the internal environment of the electrical cabinet through the high-level return air outlet, it tends to sink in the gravitational field. This sinking trend synergizes with the upward trend of the original hot air inside the cabinet due to its reduced density. In other words, the treated cold airflow naturally sinks to replace the rising hot airflow, forming a natural stratified flow based on density difference. This effect can be maintained without additional mechanical work. Second, the connection between the ejector channel and the internal environment is located in a low-level area. The entrained hot air inside the cabinet originates from the lower part of the internal space of the electrical cabinet. Inside the electrical cabinet, the less dense heated air rises naturally due to thermal buoyancy and accumulates in the upper space, while the relatively denser and cooler air settles in the lower area. Positioning the ejector channel's connection point at a low position allows air from the lower area to be preferentially drawn in and expelled, thus promoting the downward migration of the high-temperature hot air from the upper part to fill the local low-pressure area created by the suction, forming a top-down overall airflow migration path. Thirdly, the coordinated spatial layout of the high-level return air outlet and the low-level ejector inlet allows the treated cold airflow, fed in from the high position, to naturally descend along the height of the cabinet, gradually warming up as it passes through the heating area, and finally being drawn back into the circulation system at the low position. This airflow path covers the entire height range of the electrical cabinet's interior space, avoiding the short-circuit phenomenon where the treated airflow is directly drawn back before it has fully diffused. Compared to schemes that place the return air outlet and ejector inlet at the same height or arrange them randomly, the high-low coordinated configuration in this embodiment utilizes the inherent consistency between the direction of thermal buoyancy and the direction of gravity, ensuring that the airflow organization direction is consistent with rather than opposed to the natural convection direction. This results in superior airflow coverage within the cabinet with lower flow resistance. The creativity of this spatial coordination logic lies in recognizing that thermal buoyancy is no longer an interference factor that needs to be overcome, but rather an aerodynamic auxiliary driving force that can be combined with active airflow organization.

[0120] It should be noted that the gas circulation force of the method described in this embodiment is completely independent of external mechanical power sources. In step two, the acceleration and depressurization of the airflow in the second functional area is entirely determined by the geometric difference in the equivalent flow cross-section between the first and second functional areas, without involving any work input from rotating blades or reciprocating components. In step three, the entrainment of hot air in the cabinet by the local negative pressure zone is entirely driven by the pressure difference formed in step two, without involving any additional energy input. In step four, the process of treating the mixed airflow through the heat and moisture exchange medium and then returning it also does not involve any pumps or fans. The entire method only requires the presence of a heat source inside the electrical cabinet (heat dissipation generated by the normal operation of heating components and battery cells) to maintain the initial triggering of the thermal buoyancy effect, and it can be started by self-sustaining circulation under the negative pressure driven by the narrowing effect.

[0121] Based on the solutions provided in the foregoing embodiments, those skilled in the art will understand that the steps of the method described in this embodiment can also be implemented based on other physical structures that have different structures but the same functional area configuration as those in the foregoing embodiments—as long as the structure has an expansion rectification zone, a reduction acceleration zone, and a heat and humidity exchange zone connected in sequence, and the reduction acceleration zone is connected to the internal environment of the electrical cabinet through a feedback channel, the steps of the method described in this embodiment can be executed. The equivalent substitutions in the above structures do not exceed the protection scope covered by this embodiment.

[0122] Example 5. Based on the multi-level heat dissipation structure provided in the previous examples, this example further applies this heat dissipation structure to the terminal equipment level of the electrical cabinet. For example... Figure 3-4 As shown, the explosion-proof pressure relief electrical cabinet provided in this embodiment includes a cabinet body 1. The cabinet body 1 is constructed as a box-type structure with internal accommodating space, and its walls are equipped with the multi-stage heat dissipation structure described in the aforementioned embodiment. An isolation structure 13 is provided inside the cabinet body 1. The isolation structure 13 divides the interior of the cabinet body 1 into multiple working chambers.

[0123] Specifically, the isolation structure 13 divides the interior of the cabinet 1 into a first working chamber 11 and a second working chamber 12. The first working chamber 11 is used to house heat-generating components (such as power devices, converters, control circuit boards, etc.), and the second working chamber 12 is used to house battery cells (such as lithium-ion battery modules or battery packs). The isolation structure 13 is constructed as a heat-insulating partition component, and its material can be selected from heat-insulating materials (such as aerogel felt, ceramic fiber board, microporous calcium silicate board, etc.) or a heat-insulating coating can be laminated on the surface of a metal partition to reduce heat conduction between the first working chamber 11 and the second working chamber 12. Through this spatial partitioning configuration, the high temperature generated by the heat-generating components during operation is confined inside the first working chamber 11 and will not directly affect the battery cells due to heat radiation or heat conduction, thereby avoiding additional thermal shock to the battery cells caused by the high temperature of the components.

[0124] Furthermore, the aforementioned multi-stage heat dissipation structure is installed on the wall of the cabinet 1. In one specific embodiment, the wall base 21 is constructed as the door structure of the cabinet 1, and the support base 31 of the exhaust structure 3 is constructed as the door structure on the opposite side of the cabinet 1, with the two located on the front and rear sides of the cabinet 1, respectively. The feed outlet of the third chamber 25 of the multi-stage heat dissipation structure, which feeds airflow into the internal space of the cabinet 1, is opened on the wall of the second working chamber 12, so that the temperature-regulating airflow after heat and moisture exchange treatment by the third chamber 25 is directly fed into the second working chamber 12 containing the battery unit. At the same time, the opening of the feedback channel 241 in the internal space of the cabinet 1 is also opened on the wall of the second working chamber 12, so that the local negative pressure area formed at the second chamber 24 draws in the airflow inside the second working chamber 12 through the feedback channel 241. The airflow feed and suction loops are both concentrated on the second working chamber 12 where the battery unit is located, while no active airflow intervention is made on the first working chamber 11 containing the heat-generating components. The design rationale is that the thermal tolerance of the battery cell is lower than that of the power components, so priority should be given to ensuring the thermal environment control of the chamber where the battery cell is located; while the power components, due to their higher allowable operating temperature limit, only need to rely on the natural heat dissipation of the wall of the first working chamber 11 to meet the operating requirements, without the need for additional heat dissipation airflow.

[0125] exist Figure 3 and Figure 4 In the illustrated embodiment, a shelf 14 may also be provided inside the second working chamber 12. The shelf 14 is used to support battery cells in layers, maintaining appropriate airflow channels between each layer of battery modules, facilitating the flow of temperature-regulating airflow across the surface of the battery cells. The feed outlet is located in the upper region of the shelf 14, and the opening of the feedback channel 241 is located in the lower region of the shelf 14. The height difference between the two allows the temperature-regulating airflow to pass through the gap channels between each layer of battery modules from top to bottom and then be drawn back from below, achieving orderly cooling coverage of each layer of battery cells.

[0126] It is worth noting that the multi-stage heat dissipation structure in this embodiment performs temperature regulation under normal heat dissipation conditions. The microchannel plate 253 and the microporous structure of the porous sieve substrate 254 are simultaneously configured to provide flame arrest when the battery cell experiences thermal runaway. Specifically, when the battery cell in the second working chamber 12 experiences thermal runaway due to internal short circuit, overcharging, or mechanical abuse, a violent exothermic side reaction occurs inside the battery cell, releasing a large amount of high-temperature, high-pressure gas in a short time, carrying conductive carbon particles, molten metal particles, and flammable electrolyte droplets. These high-temperature ejected materials diffuse into the interior space of the cabinet 1 under pressure and may enter the third chamber 25 of the multi-stage heat dissipation structure through the feed outlet or the opening of the feedback channel 241. When high-temperature, high-pressure gas and ejected particulate matter flow through the microporous structure of the microchannel plate 253 and the porous sieve substrate 254, the ejected material undergoes multiple physical effects during its passage through the microporous structure because the size of the microporous channels is much smaller than the characteristic scale of the ejected material's movement. First, the microporous channels throttle and impede the airflow, reducing its velocity and pressure. Second, solid particles carried in the ejected material are intercepted and deposited due to inertial effects as they impact the microporous walls. Third, the high-temperature gas exchanges heat with the microchannel plate 253 and the porous sieve substrate 254, which have a large heat capacity, resulting in a significant temperature reduction. The combined effect of these multiple effects prevents the flame front from passing through the microporous structure and continuing to propagate, thus preventing open flames or high-temperature gas from directly entering the first working chamber 11 or diffusing into the external environment via the exhaust structure 3, effectively protecting the core circuit and the external environment.

[0127] It is understood that the specific implementation of the isolation structure 13 is not limited to a single flat partition. In an alternative implementation, the isolation structure 13 may adopt a hollow double-layer structure, with phase change material or thermal insulation material filled in between to further improve thermal insulation performance. In another alternative implementation, a sealing strip may be provided between the isolation structure 13 and the wall of the cabinet 1 to ensure that there is no gap for airflow communication between the first working chamber 11 and the second working chamber 12, preventing hot airflow in the first working chamber 11 from diffusing into the interior of the second working chamber 12 through the gap. The above alternative methods are all within the scope of the implementation methods covered by this embodiment. In another optional extended implementation, the wall of the first working chamber 11 may also have an independent natural ventilation opening to achieve passive heat dissipation of the first working chamber 11 by utilizing the chimney effect, without relying on the airflow distribution of a multi-stage heat dissipation structure. A protective net may be provided at the natural ventilation opening to prevent debris from entering. This solution is suitable for application scenarios where the heat load of the heating components in the first working chamber 11 is relatively low.

[0128] It is worth noting that the "explosion-proof pressure relief" function described in this embodiment does not rely on independent safety valves or rupture disc devices. Instead, it is achieved by configuring the geometric characteristics of the microporous channels in the heat dissipation structure to exhibit different fluid transfer characteristics under normal heat dissipation conditions and extreme thermal runaway conditions. Under normal conditions, the resistance of the microporous channels to airflow is within an acceptable range and does not affect the normal operation of the heat dissipation cycle. Under thermal runaway conditions, the throttling effect of the microporous channels on high-pressure ejected materials significantly increases with increasing flow velocity, forming an automatic flow limiting and flame arresting safety protection effect. This passive safety response mechanism requires no sensors, controllers, or actuators, fundamentally avoiding the risk of protection failure caused by electronic control system malfunctions.

[0129] All the above embodiments merely illustrate implementation methods for relevant practical applications of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A heat-driven circulation method for dissipating heat from the internal environment of an electrical cabinet through gas circulation force, characterized in that, The gas circulation force originates from the thermal buoyancy caused by the temperature difference of the gas flow and / or the pressure difference generated by the sudden change in the flow cross section. The thermally driven circulation method includes the following steps: The low-temperature airflow from the outside flows into the first functional area with a first equivalent flow cross section, so that the low-temperature airflow changes to a state of flowing in a preset direction; The low-temperature airflow is passed through a second functional region having a second equivalent flow cross-section smaller than the first equivalent flow cross-section, so that the flow velocity of the low-temperature airflow in the second functional region increases and the static pressure decreases, thereby forming a local negative pressure zone in the second functional region with a pressure lower than that of the internal environment. The pressure difference between the local negative pressure zone and the internal environment causes the high-temperature airflow in the internal environment to be drawn into the low-temperature airflow through the channel connecting the second functional area and the internal environment, so as to form a mixed airflow. The mixed airflow is then returned to the internal environment.

2. The thermally driven cycle method according to claim 1, characterized in that: Before the low-temperature airflow enters the second functional area, it first flows through a diversion channel located upstream of the third functional area. Part of the airflow is guided into the third functional area to participate in heat exchange, while the other part of the airflow enters the second functional area to generate local negative pressure. The mass flow rate of the airflow entering the second functional area is less than the mass flow rate of the airflow entering the third functional area.

3. The thermally driven cycle method according to claim 1 or 2, characterized in that: After the mixed airflow is formed, the mixed airflow is subjected to heat and moisture exchange with the heat and moisture exchange medium located inside the third functional area, and the heat and moisture exchanged airflow is returned to the internal environment.

4. A multi-stage heat dissipation structure, characterized in that, Used to implement the thermally driven cycle method as described in any one of claims 1 to 3; The multi-stage heat dissipation structure includes: Wall substrate (21); and, A first cavity (23) with a first volume is opened inside the wall substrate (21), and the first cavity (23) is provided with an air inlet (22) for connecting to the outside atmosphere. The second cavity (24) with a second volume is connected downstream of the first cavity (23) through the first airflow channel, and the equivalent flow cross section of the second cavity (24) is smaller than the equivalent flow cross section of the first cavity (23), so that the airflow after lamination in the first cavity (23) forms the local negative pressure zone after entering the second cavity (24); A third cavity (25) with a third volume is connected downstream of the first cavity (23) through a second airflow channel, so that the airflow after lamination in the first cavity (23) is split into a first part entering the third cavity (25) and a second part entering the second cavity (24); The feedback channel (241) is connected at one end to the second cavity (24) and at the other end to the internal environment, so that the local negative pressure zone draws in the airflow of the internal environment through the feedback channel (241).

5. The multi-stage heat dissipation structure according to claim 4, characterized in that: The volumetric dimensions of the first cavity (23), the second cavity (24), and the third cavity (25) are configured in one of the following ways so that the first cavity (23) can accommodate the external airflow entering through the air inlet (22) and convert the airflow into a laminar flow state: The volume of the first cavity (23) is greater than the volume of either the second cavity (24) or the third cavity (25); or, The volume of the first cavity (23) is greater than the volume of the second cavity (24), and the volume of the second cavity (24) is greater than the volume of the third cavity (25), so that the multi-stage heat dissipation structure forms a pressure gradient field that decreases from the first cavity (23) to the third cavity (25).

6. The multi-stage heat dissipation structure according to claim 4 or 5, characterized in that: The equivalent flow area of ​​the second airflow channel is larger than that of the first airflow channel, so that the mass flow rate of the first part is greater than that of the second part.

7. The multi-stage heat dissipation structure according to claim 4, characterized in that: The third cavity (25) is provided with a heat and moisture exchange medium so that the first part of the airflow can exchange heat and moisture with the heat and moisture exchange medium when it flows through the third cavity (25).

8. The multi-stage heat dissipation structure according to claim 7, characterized in that: The feedback channel (241) is located at the opening of the internal environment. The opening of the feedback channel (241) is lower than the feed outlet of the third cavity (25) that feeds the airflow to the internal environment, so that the airflow after heat and moisture exchange can move upward with the help of thermal buoyancy when it is discharged.

9. The multi-stage heat dissipation structure according to claim 7, characterized in that: The heat and moisture exchange medium includes a stacked microchannel plate (253) and a porous sieve substrate (254), and at least one of the microchannel plate (253) and the porous sieve substrate (254) is coated with a phase change material coating.

10. An explosion-proof pressure relief electrical cabinet, comprising a cabinet body (1), characterized in that, The explosion-proof pressure relief electrical cabinet also includes: An isolation structure (13) divides the interior of the cabinet (1) into a first working chamber (11) and a second working chamber (12), wherein the first working chamber (11) is used to house heat-generating components, and the second working chamber (12) is used to house battery cells; and, The multi-stage heat dissipation structure as described in any one of claims 4 to 9 is installed on the wall of the cabinet (1).

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