Modular combined power-saving box-type substation

Abstract

The application discloses a modular combined power-saving box-type power distribution station and belongs to the technical field of power equipment. The modular combined power-saving box-type power distribution station comprises a cabinet body, a phase-change heat storage unit and an air duct switching module. The phase-change heat storage unit is arranged vertically on the top of the cabinet body and comprises a plurality of heat storage cavities, a composite phase-change material and a plurality of metal fins. The metal fins of adjacent heat storage cavities are vertically staggered to form a zigzag air flow channel. Adjacent cavities form a main air duct which is communicated with an electrical bin. The composite phase-change material is composed of a foamed metal framework and a phase-change working medium filled in the pores. The metal fins are partially embedded in the composite material to form an integrated heat exchanger. The air duct switching module is arranged on the top of the heat storage unit. The application realizes zero-energy consumption heat collection, cross-region recycling of waste heat in a power distribution room and greatly reduces the heat preservation energy consumption of a battery.

Description

Technical Field

[0001] This invention belongs to the field of power equipment technology, specifically relating to a modular combined energy-saving box-type substation. Background Technology

[0002] Electric vehicle battery swapping stations in cold regions face a significant energy dilemma: the power distribution room experiences heavy daytime loads and generates a large amount of heat, currently relying on forced ventilation fans to directly dissipate the waste heat. Meanwhile, the battery insulation area requires electric heating to maintain a constant temperature to ensure battery performance at low temperatures, resulting in substantial electricity consumption at night. This situation—where heat is wasted while electricity is purchased at high prices—leads to severe energy waste.

[0003] Phase change thermal storage technology enables the spatial and temporal transfer of heat, but existing thermal storage devices are difficult to directly adapt to the battery swapping station scenario. Firstly, traditional fins are only attached to the outer wall of the container, resulting in high interfacial thermal resistance with the phase change material and insufficient heat storage / release rates, making it difficult to complete heat storage within the limited daytime window. Secondly, organic phase change materials are liquid after melting, making them prone to flow and leakage when placed vertically. Existing encapsulation solutions lack effective protection against liquid level rise, which can easily lead to damper jamming and duct contamination during long-term operation. Furthermore, the heat dissipation system in the power distribution room and the insulation system in the battery compartment are disconnected, failing to automatically switch between heat storage / dissipation and heat release / insulation modes based on temperature changes.

[0004] Therefore, there is an urgent need for a modular, energy-saving box-type substation that combines efficient heat exchange, leak prevention, and reliability. Summary of the Invention

[0005] The technical problem this invention aims to solve is that the direct emission of waste heat from the power distribution room of electric vehicle battery swapping stations in cold regions leads to energy waste, and the reliance on electric heating for battery insulation areas results in high operating costs.

[0006] This invention is achieved through the following technical solution: This invention provides a modular, combined, energy-saving box-type substation, comprising: The cabinet has an electrical compartment inside and a heat dissipation assembly on one side. A phase change heat storage unit is disposed on the upper part of the cabinet. The phase change heat storage unit includes several heat storage chambers and composite phase change material disposed in the heat storage chambers. The heat storage chambers are fixedly connected with multiple layers of spaced metal fins. The multiple layers of metal fins of adjacent heat storage chambers are staggered vertically to form a zigzag airflow channel. A main ventilation channel is formed between adjacent heat storage chambers. The lower end of the main ventilation channel is connected to the electrical compartment. The composite phase change material fills the heat storage chambers and wraps the metal fins to form a heat exchanger integrated with the metal fins. The air duct switching module includes an air inlet and at least two air outlets. The air inlet is connected to the upper end of the main ventilation duct, one of the air outlets is connected to the outside, and the other air outlet is connected to the heat supply air duct leading to the battery insulation area. A rotatable damper is provided between the two air outlets.

[0007] Furthermore, the heat dissipation component includes an exhaust fan and an insect screen. The insect screen is located at the air outlet that communicates with the outside, and the exhaust fan is located at the air inlet of the air duct switching module.

[0008] Furthermore, the composite phase change material is composed of a porous high thermal conductivity framework and a phase change working fluid filled in the pores of the porous high thermal conductivity framework, and the metal fins are partially embedded inside the composite phase change material.

[0009] Furthermore, the porous high thermal conductivity skeleton is made of foam metal and has multiple slots for the metal fins to pass through.

[0010] Furthermore, the porous high thermal conductivity skeleton is provided with sealing rings in the slots to form a seal between the metal fins and the slots.

[0011] Furthermore, the air duct switching module also includes a temperature control drive element, the temperature sensing end of which is located inside the electrical compartment, and the temperature control drive element controls the start and stop of the exhaust fan according to the temperature.

[0012] Furthermore, the rotatable damper is installed in the air duct switching module via a rotating shaft, and the damper rotates around the rotating shaft to selectively connect the air inlet to one of the two air outlets.

[0013] Furthermore, an overflow prevention buffer space is reserved between the top inner wall of the heat storage cavity and the upper surface of the composite phase change material. The vertical height of the overflow prevention buffer space is greater than the liquid level rise height corresponding to the volume expansion of the composite phase change material when it changes from a solid state to a completely molten state.

[0014] Furthermore, the effective internal volume Vc of the heat storage cavity and the volume Vp of the composite phase change material in the solidification state satisfy the following relationship: Vc=Vp×(1+ε)×(1+δ)×(1+γ / 10) Wherein, ε is the volume expansion rate of the composite phase change material when it changes from a molten state to a solid state; δ is the volume percentage of the metal fins in the effective volume of the heat storage cavity, and the value of δ ranges from 10% to 20%; γ is the height-to-diameter ratio of the heat storage cavity, γ=H / D, where H is the vertical height of the heat storage cavity, and D is the equivalent diameter of the horizontal cross-section of the heat storage cavity, and the value of γ ranges from 3.0 to 8.0.

[0015] Furthermore, the heated air duct is covered with an insulation layer.

[0016] Compared with the prior art, the present invention has the following advantages: First, by optimizing the fin ratio, height-to-diameter ratio, and phase change expansion rate through reasonable volume design, the problems of low heat conversion efficiency and unstable quality caused by excessive cavity volume can be avoided.

[0017] Secondly, the metal fins are partially embedded inside the phase change material to eliminate interfacial thermal resistance, and the continuous network structure of the foamed metal provides a heat conduction path, which greatly improves the heat storage and release rate. The capillary adsorption force prevents the liquid level from dropping completely after the material melts, thus solving the problem of local volume expansion when the liquid turns into a solid.

[0018] Third, the automatic switching of temperature-controlled dampers enables cross-regional waste heat utilization, automatically controls the start and stop of exhaust fans and the direction of damper rotation, and allows for heat storage and exhaust during the day and heat release and insulation at night without human intervention. It transfers waste heat energy from the power distribution room to the battery compartment, significantly reducing the energy consumption of electric heating. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the internal structure of the modular combined energy-saving box-type substation of the present invention; Figure 2 This is a schematic diagram of the overall structure of the modular combined energy-saving box-type substation of the present invention; Figure 3 This is a schematic diagram showing the relationship between the phase change heat storage unit and the heat dissipation component of the present invention; Figure 4 This is a schematic diagram showing the relationship between the air duct switching module and the heat dissipation component of the present invention; Figure 5 This is a schematic diagram of the structure of the heat storage cavity of the present invention with metal fins installed; Figure 6 This is a schematic diagram of the heat storage cavity of the present invention without metal fins installed.

[0020] In the diagram: 1. Cabinet; 11. Electrical compartment; 12. Heat dissipation assembly; 121. Exhaust fan; 122. Insect screen; 2. Phase change heat storage unit; 21. Heat storage chamber; 211. Overflow buffer space; 22. Composite phase change material; 221. Porous high thermal conductivity frame; 2211. Groove; 2212. Sealing ring; 222. Phase change working fluid; 23. Metal fins; 24. Airflow channel; 25. Main ventilation duct; 3. Air duct switching module; 31. Air inlet; 32. Air outlet; 33. Air damper; 331. Rotating shaft; 4. Heated air duct; 41. Insulation layer. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0022] See Figures 1 to 6 The present invention provides a modular combined energy-saving box-type substation, including... Cabinet 1, with an electrical compartment 11 inside, and a heat dissipation assembly 12 on one side; Phase change heat storage unit 2, located at the top of cabinet 1, includes several heat storage chambers 21 and composite phase change material 22 disposed within the heat storage chambers 21. Multiple layers of spaced metal fins 23 are fixedly connected to the heat storage chambers 21. The multiple layers of metal fins 23 of adjacent heat storage chambers 21 are vertically staggered to form airflow channels 24, and a main ventilation channel 25 is formed between adjacent heat storage chambers 21. The lower end of the main ventilation duct 25 is connected to the electrical compartment 11. The composite phase change material 22 is filled in the heat storage cavity 21 and wrapped with metal fins 23 to form a heat exchanger integrated with the metal fins 23. The air duct switching module 3 includes an air inlet 31 and at least two air outlets 32. The air inlet 31 is connected to the upper end of the main ventilation duct 25. One air outlet 32 ​​is connected to the outside. The other air outlet 32 ​​is connected to the heat supply air duct 4 leading to the battery insulation area. A rotatable damper 33 is provided between the two air outlets 32.

[0023] Function Description The electrical compartment 11 of cabinet 1 is used to house power distribution equipment such as transformers and switchgear. The heat source area is fixed at the lower part of cabinet 1, and natural convection heat collection is achieved by utilizing the principle of heat rise and cold fall. The heat exhaust component 12 is set on one side of cabinet 1 and is used to force hot air to be discharged to the outside when the power distribution equipment overheats, retaining the basic heat dissipation function of the existing power distribution room, and realizing modular transformation or addition.

[0024] The phase change heat storage unit 2 is arranged directly above the electrical chamber 11. Utilizing the physical law that hot air has low density and rises naturally, the hot air in the electrical chamber 11 can flow into the phase change heat storage unit 2 autonomously without the need for a fan, thus achieving zero-energy waste heat collection.

[0025] The total heat storage capacity is divided into several standardized units by using multiple independent heat storage chambers 21 arranged in parallel. This allows for flexible adjustment of the heat storage capacity according to the scale of the power swapping station. The small volume of each chamber helps to improve the uniformity of heat exchange and facilitates transportation, installation, maintenance and replacement.

[0026] Based on the outdoor environmental characteristics of electric vehicles, the composite phase change material 22 uses refined paraffin wax with a melting point of 35-45℃ as the working fluid. This melting point range is higher than the battery's insulation requirements, ensuring effective heat transfer through the air temperature difference during nighttime heat release. Simultaneously, it remains below the 40-60℃ temperature of the hot air in the power distribution room, allowing for normal heat storage during the day. By utilizing the solid-liquid phase change process to absorb and release a large amount of latent heat, the material efficiently stores the brief, concentrated daytime waste heat in the power distribution room as latent heat, releasing it stably when needed at night, thus achieving peak-shifting and valley-filling of heat over time.

[0027] Metal fins 23 are fixed to the surface of the heat storage cavity 21 and can act as heat exchange elements to conduct heat from the airflow into the cavity. The multi-layered arrangement increases the heat exchange area per unit height. The high thermal conductivity of the metal fins 23 significantly reduces the thermal resistance between the hot airflow and the heat storage cavity 21. The staggered arrangement forces the originally vertically rising airflow path to repeatedly turn, forming a tortuous flow trajectory, prolonging the residence time of hot air in the phase change heat storage unit 2, and increasing the number of collisions between the airflow and the metal fins 23, thereby achieving a higher heat exchange efficiency under the same natural convection pressure difference. The main ventilation duct 25 is the channel for hot air to rise from the electrical chamber 11 to the phase change heat storage unit 2. Its lower end is directly connected to the electrical chamber 11, and its upper end is connected to the air duct switching module 3, constructing a complete and unobstructed natural convection path to ensure that heat can be transferred from the heat source to the heat storage unit with low resistance. The composite phase change material 22 is tightly filled in the heat storage cavity 21 and completely wraps the metal fins 23, so that there is no air gap between the fins and the material. Heat is directly conducted from the metal fins 23 to the interior of the composite phase change material 22, eliminating the contact thermal resistance of the traditional method of transferring heat to the phase change material base layer through the fins and then through the shell, and greatly improving the heat storage and heat release rate.

[0028] The air duct switching module 3 can control the direction of heat flow. The air inlet 31 receives the air after absorbing heat from the main ventilation duct 25. The two air outlets 32 correspond to the two working conditions of heat exhaust and heat delivery, respectively. In most cases, the air after absorbing heat is directly discharged by the heat exhaust component 12. When heat delivery is required at night, the heat delivery air outlet 32 ​​will be opened, so as to realize the single heat source to deliver to different destinations according to the working conditions and complete the cross-regional heat energy transfer.

[0029] Connect the air duct switching module 3 to the upper end of the main ventilation duct 25 and install it at the air inlet 31 to ensure that all the air flowing out from the phase change heat storage unit 2 enters the air duct switching module 3, avoiding heat loss or bypass, and ensuring the integrity and controllability of the airflow path.

[0030] The air outlet 32, which connects to the external environment, is used for daytime excess heat dissipation, while the air outlet 32, which connects to the battery insulation area, is used for nighttime waste heat utilization, thus integrating the two functions of power distribution room heat dissipation and battery compartment insulation into the same system. By changing the rotation position of the damper 33, the air inlet 31 can be selectively connected to one of the two air outlets 32, achieving the switching of operating modes with a single mechanical moving part. This avoids the use of multiple independent valves or complex electric actuators, improving system reliability.

[0031] See Figures 1 to 6 In the modular combined energy-saving box-type substation provided by this invention, the heat dissipation component 12 includes an exhaust fan 121 and an insect screen 122. The insect screen 122 is located at the air outlet 32, which connects to the outside, and the exhaust fan 121 is located at the air inlet 31 of the air duct switching module 3. The exhaust fan 121, located at the air inlet 31, connects to the main ventilation duct 25 and is activated during daytime heat dissipation mode. It applies active suction on top of natural convection to enhance airflow speed, ensuring rapid cooling of the substation under high heat generation conditions and preventing equipment overheating. During nighttime heat supply mode, the exhaust fan 121 can quickly transfer heat to the battery compartment. The insect screen 122 is installed at the end of the air outlet 32 ​​leading to the outside to prevent insects, birds, fallen leaves, and other debris from entering the air duct switching module 3 through the heat dissipation channel, avoiding jamming of the damper 33 or blockage of the air duct, and ensuring long-term operational reliability.

[0032] See Figures 4 to 6 In the modular combined energy-saving box-type substation provided by this invention, the composite phase change material 22 consists of a porous high thermal conductivity skeleton 221 and a phase change working fluid 222 filled in the pores of the porous high thermal conductivity skeleton 221. Metal fins 23 are partially embedded inside the composite phase change material 22. The porous high thermal conductivity skeleton 221 uses copper foam as a support structure. The phase change working fluid 222 is refined paraffin wax with a melting point of 35-45℃, which is filled in the pores of the porous high thermal conductivity skeleton 221. The high thermal conductivity of the porous high thermal conductivity skeleton 221 provides a rapid heat diffusion channel. At the same time, the capillary adsorption force of the skeleton pores constrains the liquid phase change working fluid 222, preventing damage due to uneven volume changes. The metal fins 23 are directly inserted into the composite phase change material 22 block, forming an embedded overlap with the porous high thermal conductivity skeleton 221. Heat is directly conducted from the metal fins 23 to the skeleton network without needing to pass through the cavity wall and air gaps, shortening the heat transfer path and significantly reducing thermal resistance.

[0033] See Figures 4 to 6In the modular combined energy-saving box-type substation provided by this invention, the porous high thermal conductivity frame 221 is made of foam metal and has multiple slots 2211 for metal fins 23 to pass through. The foam metal is specifically foamed copper, possessing a three-dimensional network structure with an open area ratio of 85%-95%, a large specific surface area, high thermal conductivity, and good compatibility with the phase change working fluid 222. Using foam metal as the frame material balances high thermal conductivity, lightweight, ease of processing, and economy. Slots 2211 corresponding to the positions of the metal fins 23 are pre-processed on the foam metal frame, allowing the metal fins 23 to be precisely inserted into the frame, solving the process problem of direct connection between the metal fins 23 and the porous material. A reliable thermal contact interface is formed through mechanical interlocking, and a waterproof structural colloid is used for leak prevention, enabling mass production.

[0034] See Figure 6 In the modular combined energy-saving box-type substation provided by this invention, a sealing ring 2212 is provided in the slots 2211 of the porous high thermal conductivity frame 221 to form a seal between the metal fins 23 and the slots 2211. The sealing ring 2212 is installed on the inner wall of the slots 2211. When the metal fins 23 are inserted, they are compressed, filling the tiny gaps between the fins and the frame. Combined with the waterproof structural colloid, it can effectively prevent the liquid phase change working fluid from leaking out along the interface between the metal fins 23 and the porous high thermal conductivity frame 221, avoiding material loss and external contamination. At the same time, the sealing ring 2212 has a certain degree of elasticity, which can adapt to the relative displacement caused by the difference in thermal expansion coefficients between the metal fins 23 and the frame, ensuring that it will not loosen during long-term operation.

[0035] See Figures 1 to 3 In the modular combined energy-saving box-type substation provided by this invention, the duct switching module 3 also includes a temperature control drive element. The temperature sensing end of the temperature control drive element is located inside the electrical compartment 11. The temperature control drive element controls the start and stop of the exhaust fan 121 according to the temperature. The temperature control drive element senses the operating temperature of the power distribution equipment and triggers an action. The temperature sensing end is directly placed in the heat source area to monitor the real temperature of the electrical compartment 11 in real time, avoiding the lag and error caused by indirect measurement. When the temperature of the electrical compartment 11 is higher than the set threshold, the exhaust fan 121 is automatically started to enhance heat dissipation. When the temperature drops below the set threshold, the exhaust fan 121 is automatically stopped. No manual intervention or additional controller is required, realizing unattended operation around the clock. Moreover, the exhaust fan 121 only works when heat dissipation is needed, further reducing system energy consumption.

[0036] See Figure 4In the modular combined energy-saving box-type substation provided by this invention, a rotatable damper 33 is installed in the air duct switching module 3 via a rotating shaft 331. The damper 33 rotates around the rotating shaft 331 to selectively connect the air inlet 31 to one of the two air outlets 32. The rotating shaft 331 provides a pivot point for the damper 33, positioning it at the intersection of the air inlet 31 and the two air outlets 32. The installation method is simple in structure and reliable in operation. The rotating shaft 331 can be equipped with bearings to ensure durability for long-term frequent rotation. At the two extreme positions of the rotation stroke, the damper 33 completely connects the air inlet 31 to either the heat exhaust outlet 32 ​​or the heat supply outlet 32, while the other air outlet 32 ​​is closed by the damper 33 body.

[0037] See Figures 3 to 6 In the modular combined energy-saving box-type substation provided by this invention, 8. the modular combined energy-saving box-type substation according to claim 1, characterized in that an overflow buffer space 211 is reserved between the top inner wall of the heat storage chamber 21 and the upper surface of the composite phase change material 22. The vertical height of the overflow buffer space 211 is greater than the liquid level rise corresponding to the volume expansion of the composite phase change material 22 when it changes from a solid state to a completely molten state. An air layer without the composite phase change material 22 is reserved at the top of the heat storage chamber 21. When the phase change working medium 222 is heated and melts and expands in volume, the liquid material rises into this buffer space, which is less likely to damage the heat storage chamber 21. The buffer space is greater than the volume rise corresponding to the volume expansion of the phase change working medium 222 from a completely molten state to a completely solid state, ensuring that the solid material is always constrained within the overflow buffer space 211 throughout the entire phase change process.

[0038] See Figures 4 to 6 In the modular combined energy-saving box-type substation provided by the present invention, the effective internal volume Vc of the heat storage cavity 21 and the volume Vp of the composite phase change material 22 in the solidified state satisfy the following relationship: Vc=Vp×(1+ε)×(1+δ)×(1+γ / 10) Wherein, ε is the volume expansion rate of the composite phase change material 22 when it changes from a solid state to a fully molten state; δ is the volume percentage of the metal fins 23 in the effective volume of the heat storage cavity 21, and the value of δ ranges from 10% to 20%; γ is the height-to-diameter ratio of the heat storage cavity 21, γ=H / D, where H is the vertical height of the heat storage cavity 21, D is the equivalent diameter of the horizontal cross-section of the heat storage cavity 21, and the value of γ ranges from 3.0 to 8.0.

[0039] Paraffin wax was selected as the phase change working medium 222, with a volume expansion rate ε=12% (0.12). The foamed copper skeleton 221 was composite with the phase change material 22. The metal fins 23 were arranged in a staggered and dense layout. The calculated volume percentage of the metal fins 23 in the effective volume of the heat storage cavity 21 was δ=15% (0.15). The heat storage cavity 21 was designed with a square cross section, with a side length D=200mm, a height H=800mm, and a height-to-diameter ratio γ=H / D=4.0.

[0040] The volume of the composite phase change material 22 in the solidified state within a single heat storage chamber 21 is Vp = 0.025 m³. 3 .

[0041] Substitute into the formula to calculate: Vc=Vp×(1+ε)×(1+δ)×(1+γ / 10) =0.025×(1+0.12)×(1+0.15)×(1+4.0 / 10) =0.025×1.12×1.15×1.40 =0.025×1.8032 =0.04508m 3 The calculated theoretical minimum volume is 0.045 m³. 3 In this embodiment, the actual designed internal volume of the heat storage chamber 21 is 0.048 m³. 3 The design meets the formula requirements and allows for a reasonable margin. Actual testing showed that the design operated continuously for 30 days at -35℃ without any leakage of the liquid phase change working fluid or damper jamming, and its heat storage and release performance met the design specifications.

[0042] The value of δ ranges from 10% to 20%, which corresponds to the volume ratio of the metal fins 23 in the effective volume of the heat storage cavity 21. If it is less than 10%, the heat exchange area is insufficient, and the heat storage and heat release rates are limited. If it is more than 20%, the metal fins 23 are too dense, the airflow resistance is too large, and it occupies the filling space of the composite phase change material 22.

[0043] The value of γ ranges from 3.0 to 8.0, which corresponds to the ratio of the vertical height of the heat storage cavity 21 to the equivalent diameter of the horizontal cross section. When γ is less than 3.0, the cavity tends to be short and wide, the hot air flow is too short, and the heat exchange is insufficient. When γ is greater than 8.0, the cavity is too thin and tall, the airflow resistance increases significantly, and the natural convection driving force is insufficient.

[0044] See Figures 1 to 6In the modular combined energy-saving box-type substation provided by this invention, the heat supply duct 4 is covered with an insulation layer 41. The heat supply duct 4 is a heat transport channel extending from the substation to the battery insulation area. The insulation layer 41 covers the outer wall of the heat supply duct 4, which significantly reduces the temperature drop and heat loss of hot air during long-distance transport, ensuring that heat can be delivered to the battery insulation area at a sufficient temperature during nighttime heat release mode, thereby improving the waste heat utilization efficiency.

[0045] Explanation of the working process and principle of this embodiment The electrical equipment in the electrical compartment 11 generates heat during operation, which heats the surrounding air. The density of the hot air decreases, and it rises autonomously under the action of buoyancy. It enters the phase change heat storage unit 2 through the main ventilation duct 25. This process relies on natural convection and does not require power equipment.

[0046] After hot air enters the phase change heat storage unit 2, it flows through the airflow channel 24 formed by the staggered arrangement of metal fins 23 between adjacent heat storage chambers 21. The airflow path repeatedly turns, making full contact with the multi-layer metal fins 23 for heat exchange. The heat is conducted to the interior of the heat storage chamber 21 through the metal fins 23.

[0047] The heat storage chamber 21 is filled with a composite phase change material 22, which is composed of copper foam and paraffin. The metal fins 23 are partially embedded in the composite phase change material 22 and sealed by a sealing ring 2212. Heat is directly conducted from the metal fins 23 to the porous high thermal conductivity skeleton 221. The high thermal conductivity of the copper foam allows the heat to spread rapidly throughout the entire block. The phase change working fluid 222 absorbs heat and melts, and the latent heat of phase change is stored.

[0048] When the temperature drops at night, the phase change working fluid 222 solidifies and releases heat. The stored heat is slowly released, and the surface of the composite phase change material 22 and the metal fins 23 are heated. The heated air is then transported to the battery insulation area through the air duct switching module 3 and the heat delivery air duct 4.

[0049] The air inlet 31 of the air duct switching module 3 is connected to the upper end of the main ventilation duct 25. The damper 33 is installed in the module via a rotating shaft 331 and can be rotated between two extreme positions. The temperature sensing end of the temperature control drive element is located in the electrical compartment 11 to monitor the temperature in real time.

[0050] When the temperature of the electrical compartment 11 is ≥50℃, the temperature control drive element drives the damper 33 to rotate to the heat dissipation position, connecting the air inlet 31 with the air outlet 32 ​​leading to the outside. At the same time, the exhaust fan 121 is activated to force exhaust air. The hot air is exhausted to the outside through the air duct switching module 3, the exhaust fan 121, and the insect screen 122, achieving forced heat dissipation of the power distribution room. Meanwhile, the residual heat is partially stored when flowing through the phase change heat storage unit 2. In the heat supply mode, the damper 33 rotates back to the heat supply position, connecting the air inlet 31 with the heat supply air duct 4. The composite phase change material 22 releases the stored heat to heat the air. The hot air flows into the battery insulation area through the heat supply air duct 4 under the action of the exhaust fan 121, achieving zero-energy heat preservation.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular, combined, energy-saving box-type substation, characterized in that, include: The cabinet has an electrical compartment inside and a heat dissipation assembly on one side. A phase change heat storage unit is disposed on the upper part of the cabinet. The phase change heat storage unit includes several heat storage chambers and composite phase change material disposed in the heat storage chambers. The heat storage chambers are fixedly connected with multiple layers of spaced metal fins. The multiple layers of metal fins of adjacent heat storage chambers are staggered vertically to form a zigzag airflow channel. A main ventilation channel is formed between adjacent heat storage chambers. The lower end of the main ventilation channel is connected to the electrical compartment. The composite phase change material fills the heat storage chambers and wraps the metal fins to form a heat exchanger integrated with the metal fins. The air duct switching module includes an air inlet and at least two air outlets. The air inlet is connected to the upper end of the main ventilation duct, one of the air outlets is connected to the outside, and the other air outlet is connected to the heat supply air duct leading to the battery insulation area. A rotatable damper is provided between the two air outlets.

2. The modular combined energy-saving box-type substation according to claim 1, characterized in that, The heat dissipation component includes an exhaust fan and an insect screen. The insect screen is located at the air outlet that connects to the outside, and the exhaust fan is located at the air inlet of the air duct switching module.

3. The modular combined energy-saving box-type substation according to claim 1, characterized in that, The composite phase change material is composed of a porous high thermal conductivity skeleton and a phase change working fluid filled in the pores of the porous high thermal conductivity skeleton, and the metal fins are partially embedded inside the composite phase change material.

4. A modular combined energy-saving box-type substation according to claim 3, characterized in that, The porous, high thermal conductivity skeleton is made of foam metal and has multiple slots for the metal fins to pass through.

5. A modular combined energy-saving box-type substation according to claim 4, characterized in that, The porous high thermal conductivity skeleton is provided with sealing rings in the slots to form a seal between the metal fins and the slots.

6. A modular combined energy-saving box-type substation according to claim 2, characterized in that, The air duct switching module also includes a temperature control drive element, the temperature sensing end of which is located inside the electrical compartment, and the temperature control drive element controls the start and stop of the exhaust fan according to the temperature.

7. A modular combined energy-saving box-type substation according to claim 1, characterized in that, The rotatable damper is installed in the air duct switching module via a rotating shaft. The damper rotates around the rotating shaft to selectively connect the air inlet to one of the two air outlets.

8. A modular combined energy-saving box-type substation according to claim 1, characterized in that, An overflow prevention buffer space is reserved between the top inner wall of the heat storage cavity and the upper surface of the composite phase change material. The vertical height of the overflow prevention buffer space is greater than the liquid level rise height corresponding to the volume expansion of the composite phase change material when it changes from a solid state to a completely molten state.

9. A modular combined energy-saving box-type substation according to claim 1, characterized in that, The effective internal volume Vc of the heat storage cavity and the volume Vp of the composite phase change material in the solidified state satisfy the following relationship: Vc=Vp×(1+ε)×(1+δ)×(1+γ / 10) Wherein, ε is the volume expansion rate of the composite phase change material when it changes from a molten state to a solid state; δ is the volume percentage of the metal fin array in the effective volume of the heat storage cavity, and the value of δ ranges from 10% to 20%; γ is the height-to-diameter ratio of the heat storage cavity, γ=H / D, where H is the vertical height of the heat storage cavity, and D is the equivalent diameter of the horizontal cross-section of the heat storage cavity, and the value of γ ranges from 3.0 to 8.

0.

10. A modular combined energy-saving box-type substation according to claim 1, characterized in that, The hot air duct is covered with an insulation layer.

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