A waterproof type pole-mounted circuit breaker

Abstract

The application relates to the technical field of electrical control protection, and relates to a waterproof pole circuit breaker, which comprises an arc extinguishing chamber, an operating mechanism box, a current transformer, a voltage transformer and a disconnector. The operating mechanism box comprises a box body, the inner side of the box body is horizontally fixedly connected with a partition plate, the inner side of the box body is divided into an upper equipment mounting cavity and a lower humidity adjusting cavity by the partition plate, a phase change heat accumulation unit is arranged on the top of the upper equipment mounting cavity, heat-conducting silicone grease is arranged between the phase change heat accumulation unit and the box body, a plurality of air passage micropores are uniformly arranged on the partition plate, the upper equipment mounting cavity and the lower humidity adjusting cavity are communicated through the air passage micropores, and a humidity buffer unit is arranged in the lower humidity adjusting cavity. The phase change heat accumulation unit and the humidity buffer unit construct a compact, efficient and completely passive temperature and humidity collaborative regulation system, can synchronously suppress temperature fluctuation and humidity change in the box, and effectively solve the internal condensation problem of the outdoor metal box body caused by the breathing effect and temperature sudden change.

Description

Technical Field

[0001] This invention relates to the field of electrical control and protection technology, and in particular to a waterproof pole-mounted circuit breaker. Background Technology

[0002] Pole-mounted circuit breakers are critical protection and control devices for overhead power lines in distribution networks. Their operating mechanism box, serving as the "power and control core" of the circuit breaker, integrates precision mechanical and electrical components such as opening and closing motors, spring energy storage mechanisms, linkage transmission systems, limit switches, micro switches, control circuit boards, and secondary wiring terminals. This box is typically made of metal (such as cast aluminum or stainless steel) and is directly installed on the utility pole, exposed year-round to harsh outdoor environments including extreme temperature fluctuations, high humidity, rain, snow, salt spray, and strong ultraviolet radiation. In a conventional pole-mounted circuit breaker structure, the operating mechanism box, as a relatively independent sealed unit, is connected to external actuators such as the arc-extinguishing chamber and disconnecting switches via mechanical linkage components. The stability of its internal environment directly affects the reliable operation of the entire circuit breaker.

[0003] Due to the low heat capacity and rapid thermal conductivity of metal enclosures, coupled with their relatively sealed internal space, severe internal condensation is highly likely to occur under complex outdoor climatic conditions. Condensation formation is primarily based on two physical mechanisms: First, the breathing effect. When the enclosure experiences a drop in internal air temperature and volume contraction due to nighttime radiative cooling, a pressure difference is created between the inside and outside of the enclosure, drawing in humid external air through microscopic gaps or interfaces in the seals. Second, direct condensation due to sudden temperature changes. In hot and humid weather, the enclosure surface cools rapidly due to sudden rainfall or rapid nighttime cooling, causing water vapor in the air inside the enclosure to condense directly into liquid water on the inner walls or component surfaces where the temperature has dropped below the dew point. Continuous condensation can lead to a series of serious consequences: water droplets adhering to electrical terminals, circuit boards, and metal surfaces cause reduced insulation and increased short-circuit risk; it can cause corrosion of metal components, jamming of moving mechanisms, and poor contact of microswitches; and in low-temperature environments, it can even freeze, causing mechanical damage. These faults seriously threaten the reliable operation of pole-mounted circuit breakers and the safe and stable operation of the power grid.

[0004] Currently, the industry mainly relies on several traditional solutions for preventing condensation in control unit enclosures: First, installing electric heaters or semiconductor temperature controllers inside the enclosure to actively reduce relative humidity through heating. This method is energy-intensive, and uneven heating may create new temperature gradients, leading to condensation in some areas. It also increases system complexity and potential points of failure. Second, installing drain holes or drain valves at the bottom of the enclosure. While this can drain existing condensate, it compromises the overall airtightness of the enclosure, providing a channel for the intrusion of external humid air and dust, exacerbating the breathing effect, and the drain holes are easily clogged by dirt.

[0005] In summary, existing anti-condensation technologies generally suffer from high energy consumption and weak sealing when dealing with long-term, complex, and variable outdoor operating environments. Therefore, a novel protection approach and structural design are urgently needed to effectively suppress or even eliminate condensation without relying on continuous external energy input or compromising the overall high sealing level of the enclosure. This would significantly improve the operational reliability and service life of pole-mounted circuit breaker operating mechanism boxes in harsh outdoor environments. The improvements in this invention are based on the specific application scenario of pole-mounted circuit breaker operating mechanism boxes. Without altering their connection relationships and basic functions with external components such as the arc-extinguishing chamber and instrument transformers, innovative designs are made to the internal structure of the enclosure to solve the long-standing problem of condensation. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a waterproof pole-mounted circuit breaker.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A waterproof pole-mounted circuit breaker includes an arc-extinguishing chamber, an operating mechanism box, a current transformer, a voltage transformer, and a disconnecting switch. The operating mechanism box includes a housing, with a partition horizontally fixed to the inner side of the housing. The partition divides the inner side of the housing into an upper equipment mounting cavity and a lower humidity regulating cavity. A phase change heat storage unit is installed on the top of the upper equipment mounting cavity. Thermally conductive silicone grease is applied between the phase change heat storage unit and the housing. Multiple ventilation micro-holes are evenly distributed on the partition. The upper equipment mounting cavity and the lower humidity regulating cavity are connected through the ventilation micro-holes. A humidity buffer unit is provided inside the lower humidity regulating cavity.

[0009] Preferably, the phase change heat storage unit includes a metal encapsulation shell, a phase change material core, and heat-conducting fins. A mounting boss is fixedly provided on the top of the upper equipment mounting cavity. The top surface of the metal encapsulation shell is mounted on the mounting boss by screws. The phase change material core is a fatty acid-based phase change material with a melting point of 38°C to 42°C. The heat-conducting fins are aluminum sheets, and multiple heat-conducting fins are vertically welded to the bottom of the metal encapsulation shell.

[0010] Preferably, the metal encapsulation housing is provided with a one-way exhaust valve on its side, which is used to discharge the gas inside the metal encapsulation housing.

[0011] Preferably, the humidity buffer unit includes a box body, a plurality of positioning rings are provided on the side wall of the lower humidity regulating cavity, and positioning blocks are provided on the side wall of the box body corresponding to the positioning rings. The inner cavity of the box body is filled with a humidity buffer material, which has reversible moisture absorption and release characteristics.

[0012] Preferably, the humidity buffer material is modified aluminosilicate particles with a particle size of 2 mm to 4 mm. The modified aluminosilicate particles have a hydrophobic surface and a hierarchical pore structure with micropores having a diameter of 0.4 nm to 0.6 nm and mesopores having a diameter of 2 nm to 5 nm.

[0013] Preferably, the inner side of the box wall is provided with a temperature gradient blocking layer, which includes a polyimide film, closed-cell foamed polyethylene and aluminum foil arranged sequentially from the inside to the outside. The polyimide film, closed-cell foamed polyethylene and aluminum foil are bonded to the inner surface of the box wall after being composited by a hot pressing process.

[0014] Preferably, the upper surface of the partition plate is provided with multiple flow guide grooves, and the bottom of the flow guide grooves is provided with multiple downward-through drainage micro-holes, which are positioned directly opposite the humidity buffer unit.

[0015] Preferably, the partition is made of a high thermal conductivity metal, and a plurality of vertically downward thermally conductive fins are fixed on the lower surface of the partition. The thermally conductive fins extend to the lower humidity regulating cavity and are located on the side of the humidity buffer unit.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention integrates a phase change heat storage unit, a humidity buffer unit, and an internal cavity partition with ventilated micropores into a single enclosure, constructing a compact, efficient, and completely passive temperature and humidity coordinated control system. This structure can simultaneously suppress temperature fluctuations and humidity changes within the enclosure, fundamentally eliminating the conditions for condensation formation and effectively solving the problem of internal condensation in outdoor metal enclosures caused by the breathing effect and sudden temperature changes. It requires no external energy input and achieves dynamic moisture balance within the enclosure while maintaining a high overall sealing level, significantly improving the long-term operational reliability, maintenance-free operation, and service life of the equipment in harsh environments. The improvements of this invention are directly applied to the operating mechanism box of pole-mounted circuit breakers, providing a systematic solution to the condensation problem faced by this specific component during outdoor operation. Working in conjunction with the circuit breaker's original arc extinguishing, measurement, and isolation functional modules, it jointly enhances the overall environmental adaptability and reliability of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a partial structural diagram of the operating mechanism box in this invention. Figure 1 ;

[0020] Figure 3 This is a partial structural diagram of the operating mechanism box in this invention. Figure 1 ;

[0021] Figure 4 This is a partial structural diagram of the present invention. Figure 1 ;

[0022] Figure 5 This is a partial cross-sectional view of the partition plate in this invention;

[0023] Figure 6 This is a partial structural diagram of the present invention. Figure 2 ;

[0024] Figure 7 This is a schematic diagram of the temperature gradient blocking layer in this invention.

[0025] In the diagram: 1. Housing; 101. Upper equipment mounting cavity; 102. Lower humidity control cavity; 2. Partition; 201. Ventilation micropores; 202. Flow guide groove; 203. Drainage micropores; 3. Phase change heat storage unit; 31. Metal encapsulation shell; 32. Phase change material core; 33. Thermal conductive fins; 34. One-way exhaust valve; 4. Thermal conductive silicone grease; 5. Humidity buffer unit; 51. Box body; 52. Positioning insert; 53. Humidity buffer material; 6. Mounting boss; 7. Screw; 8. Positioning ring; 9. Temperature gradient blocking layer; 91. Polyimide film; 92. Closed-cell foamed polyethylene; 93. Aluminum foil; 10. Thermal conductive fins. Detailed Implementation

[0026] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] like Figure 1-7This invention provides a waterproof pole-mounted circuit breaker, comprising an arc-extinguishing chamber, an operating mechanism box, a current transformer, a voltage transformer, and a disconnecting switch. Each component is assembled according to the conventional functional layout of a distribution network circuit breaker, maintaining the original core transmission and electrical connection logic. Specifically, the operating mechanism box serves as the core unit for integrated control and execution, internally housing key components such as a closing / opening motor, a spring energy storage mechanism, a linkage transmission system, limit switches, and a control circuit board, undertaking the circuit breaker's opening and closing power output and logic control functions. The arc-extinguishing chamber adopts a vacuum arc-extinguishing chamber structure, located at the top of the circuit breaker, and is fixed to the top of the operating mechanism box by bolts. Its moving contact linkage penetrates the top wall of the operating mechanism box, forming a rigid transmission connection with the closing / opening transmission mechanism inside the operating mechanism box, used to accommodate and extinguish the arc-extinguishing process. The arc generated during the process; the current transformer adopts a through-hole structure and is fitted outside the conductive rod on the incoming side of the arc-extinguishing chamber, with its outer shell fixed to the flange at the incoming end of the arc-extinguishing chamber by a bracket; the voltage transformer adopts a cast-in-place structure and is fixed to the outside of the side wall of the operating mechanism box, with one end of its primary winding electrically connected to the conductive rod on the outgoing side of the arc-extinguishing chamber and the other end grounded; the outgoing ends of the secondary windings of both the current transformer and the voltage transformer are introduced into the control circuit board inside the operating mechanism box through weather-resistant sealed terminals, used to collect line current and voltage signals and feed them back to the control unit; the disconnecting switch adopts a rotary structure and is installed outside the incoming end of the arc-extinguishing chamber through a rotating shaft bracket, with its operating shaft linked to the spring energy storage mechanism inside the operating mechanism box through a coupling, realizing interlocking with the opening and closing actions of the arc-extinguishing chamber, used to form a visible disconnection point of the line. The improvement of this invention mainly focuses on the box structure itself. The operating mechanism box includes a box body 1. A partition 2 is horizontally fixed to the inner side of the box body 1. The partition 2 divides the inner side of the box body 1 into an upper equipment mounting cavity 101 and a lower humidity regulating cavity 102. A phase change heat storage unit 3 is installed on the top of the upper equipment mounting cavity 101. Thermal conductive silicone grease 4 is provided between the phase change heat storage unit 3 and the box body 1. A plurality of ventilation microholes 201 are evenly distributed on the partition 2. The upper equipment mounting cavity 101 and the lower humidity regulating cavity 102 are connected through the ventilation microholes 201. A humidity buffer unit 5 is provided in the lower humidity regulating cavity 102 to realize active regulation of the internal temperature and humidity environment.

[0028] Specifically, the phase change heat storage unit 3 includes a metal encapsulation shell 31, a phase change material core 32, and heat-conducting fins 33. A mounting boss 6 is fixedly provided on the top of the upper equipment mounting cavity 101. The top surface of the metal encapsulation shell 31 is mounted on the mounting boss 6 by screws 7. The phase change material core 32 is a fatty acid-based phase change material with a melting point of 38°C to 42°C. The heat-conducting fins 33 are aluminum sheets, and multiple heat-conducting fins 33 are vertically welded to the bottom of the metal encapsulation shell 31. The heat-conducting fins 33 are provided to enhance the heat transfer efficiency between the phase change material core 32 and the air inside the housing 1.

[0029] Specifically, a one-way exhaust valve 34 is provided on the side of the metal encapsulation housing 31. The one-way exhaust valve is used to discharge the gas inside the metal encapsulation housing 31. The valve has a one-way self-sealing structure, and the valve core is made of a stainless steel ball pre-tightened by a spring. The inner diameter of the valve seat is 2mm. During the long-term operation of the phase change material core 32, if a small amount of gas is generated due to thermal cycling, the internal pressure will gradually increase. When the pressure exceeds 0.05MPa, the stainless steel ball is pushed open, and the gas is discharged through the valve seat. After the pressure is released, the spring pushes the stainless steel ball to reset, resealing the valve port, thus preventing the positive pressure inside the housing 1 from being too high due to gas accumulation, which could affect the sealing performance or cause structural deformation.

[0030] Specifically, the humidity buffer unit 5 includes a housing 51, and multiple positioning rings 8 are provided on the side wall of the lower humidity regulating cavity 102. Positioning blocks 52 are provided on the side wall of the housing 51 corresponding to the positioning rings 8. The inner cavity of the housing 51 is filled with humidity buffer material 53. The humidity buffer material 53 has reversible moisture absorption and release characteristics. The moisture absorption and release process of the humidity buffer material 53 is a completely passive physical process, driven by its own material properties and the difference in ambient humidity, without the need for external control. Its working principle is based on the adsorption equilibrium principle of water molecules: when the relative humidity of the air inside the chamber 1 increases, that is, when the partial pressure of water vapor in the air is higher than the equilibrium partial pressure of water vapor in the micropores on the surface of the humidity buffer material 53, water molecules, driven by the concentration difference or partial pressure difference, spontaneously diffuse into the micropores of the material and are adsorbed, thereby reducing the humidity of the air inside the chamber; conversely, when the relative humidity of the air inside the chamber decreases, that is, when the partial pressure of water vapor in the air is lower than the equilibrium partial pressure in the micropores of the material, the adsorbed water molecules will desorb from the material and be released into the air to slow down the rapid decrease in humidity; when the humidity of the air inside the chamber 1 increases due to temperature fluctuations, the humidity buffer material 53 adsorbs water molecules to inhibit the formation of dew point; when the humidity decreases, the humidity buffer material 53 releases the adsorbed water molecules to maintain a moderate humidity and avoid excessive dryness that leads to static electricity accumulation.

[0031] Specifically, the humidity buffer material 53 is a modified aluminosilicate particle with a particle size of 2 mm to 4 mm. The surface of the modified aluminosilicate particle is hydrophobically treated, and the interior has a hierarchical pore structure with micropores of 0.4 nm to 0.6 nm and mesopores of 2 nm to 5 nm. Based on its hierarchical pore structure and surface hydrophobic treatment, the modified aluminosilicate particle exhibits excellent reversible moisture absorption and release kinetics. During the diurnal temperature and humidity cycle inside the chamber 1, it can effectively buffer humidity fluctuations, absorb supersaturated moisture, and slowly release it when the environment is dry, thereby maintaining the relative humidity inside the chamber 1 at a low and stable level.

[0032] Specifically, a temperature gradient blocking layer 9 is provided on the inner side wall of the enclosure 1. The temperature gradient blocking layer 9 includes a polyimide film 91, a closed-cell foamed polyethylene 92, and an aluminum foil 93 arranged sequentially from the inside to the outside. The polyimide film 91, the closed-cell foamed polyethylene 92, and the aluminum foil 93 are bonded to the inner surface of the side wall of the enclosure 1 after being composited by a hot-pressing process. The temperature gradient blocking layer 9 covers the entire area of ​​the side wall of the enclosure 1 except for the mounting flange. The polyimide film 91, the closed-cell foamed polyethylene 92, and the aluminum foil 93 are pre-composite by a hot-pressing process and then bonded to the inner surface of the side wall of the enclosure 1 with weather-resistant epoxy resin. This composite structure uses the low thermal conductivity of the closed-cell foamed polyethylene 92 to block heat conduction, the polyimide film 91 to provide electrical insulation and high temperature resistance, and the aluminum foil 93 to reflect external radiant heat, together reducing the conduction rate of temperature fluctuations from the outer wall of the enclosure 1 to the interior of the enclosure 1.

[0033] Specifically, the upper surface of the partition 2 is provided with multiple guide channels 202, and the bottom of the guide channels 202 is provided with multiple downward-through drainage microholes 203. The drainage microholes 203 are set directly opposite the humidity buffer unit 5. When condensation occurs in the upper equipment installation cavity 101 due to the temperature difference between day and night or sudden changes in the external environment, causing the local temperature to drop below the dew point, the water droplets first adhere to the electrical components or the inner wall of the housing 1. Then, under the action of gravity and surface tension, they gather along the guide channels 202 to the drainage microholes 203 and slowly seep into the lower humidity regulating cavity 102. Finally, they are captured and stored by the humidity buffer material 53 in the humidity buffer unit 5 to prevent moisture accumulation from causing electrical short circuits or corrosion.

[0034] Specifically, the partition 2 is made of a high thermal conductivity metal, and multiple vertically downward-pointing heat-conducting fins 10 are fixed on the lower surface of the partition 2. The heat-conducting fins 10 extend to the lower humidity regulating cavity 102 and are located on the side of the humidity buffer unit 5. This structure establishes an efficient heat conduction path between the upper and lower chambers by making the partition 2 a high thermal conductivity metal and adding downward-pointing heat-conducting fins 10. Its functions are: first, to quickly and evenly transfer the heat absorbed or released by the top phase change heat storage unit 3 to the lower humidity regulating cavity 102, balancing the temperature field of the entire box 1 and avoiding the formation of low-temperature dead zones in the lower part; second, the heat-conducting fins 10 are located on the side of the humidity buffer unit 5, which can conduct appropriate thermal interaction with the surrounding air and buffer material. This can help maintain the temperature of the buffer unit at low temperatures and prevent condensation on its surface, and can also promote the stable storage of adsorbed moisture at high temperatures, thereby strengthening the synergistic effect of phase change temperature control and humidity buffering, and improving the overall anti-condensation reliability of the system under extreme temperature differences.

[0035] In actual operation, the operating mechanism box is installed on an outdoor utility pole, exposed to sunlight, rain, and diurnal temperature variations. During the day, sunlight causes the temperature of the outer wall of the box 1 to rise, and the heat is conducted to the interior of the box 1 through the wall. The phase change material core 32 in the phase change heat storage unit 3 absorbs the heat and undergoes a solid-liquid phase change, storing latent heat and slowing down the rate of internal temperature rise. At night, when the temperature drops, the phase change material core 32 releases latent heat and undergoes a liquid-solid phase change, suppressing a sudden drop in internal temperature. During this temperature fluctuation, the air volume in the upper equipment mounting cavity 101 expands or contracts accordingly, driving humid air to enter or exit the lower humidity regulating cavity 102 through the ventilation micropores 201. By optimizing the hierarchical pore structure and surface hydrophobication treatment process of the modified aluminosilicate particles, a fixed critical relative humidity threshold for hygroscopic absorption is formed. When the relative humidity of the air inside the chamber 1 is higher than the critical relative humidity, the capillary adsorption force generated by the micropores and mesopores inside the modified aluminosilicate particles is greater than the desorption force of water molecules. The particles automatically adsorb water molecules in the air, reducing the relative humidity in the upper equipment mounting cavity 101. When the relative humidity of the air inside the chamber 1 is lower than the critical relative humidity, the desorption force of water molecules is greater than the adsorption force of the particles. The water molecules adsorbed by the particles are slowly released into the air, maintaining the relative humidity in the upper equipment mounting cavity 101 within a suitable range and avoiding excessive dryness that leads to static electricity accumulation. At the same time, if condensation forms in a local area due to a sudden drop in temperature, water droplets collect along the guide channel 202 and enter the lower humidity regulating cavity 102 through the drainage micropores 203, where they are captured by the humidity buffer material 53. The entire system requires no external energy input, relying on the physical properties of the materials themselves and the structural design to achieve passive regulation of temperature and humidity, ensuring the long-term stable operation of the internal electrical components. All components are reliably secured by mechanical connections, adhesives, snap-fits, or threaded fasteners.

[0036] To enable those skilled in the art to fully understand and implement this invention, the following explanation further elaborates on the specific implementation principles of this invention in conjunction with a typical outdoor power distribution application scenario.

[0037] In 10kV distribution network lines, pole-mounted circuit breaker operating mechanism boxes are exposed to high temperature and humidity, strong sunlight, and frequent rainfall for extended periods, with an average annual relative humidity exceeding 85% and a diurnal temperature range of over 15°C. The waterproof operating mechanism box described in this invention is now installed on the pole support of this line, and its operation process is as follows:

[0038] First, under the influence of solar radiation during the day, the temperature of the outer wall of the enclosure 1 rises rapidly, and heat is conducted into the interior of the enclosure 1. At this time, the phase change heat storage unit 3, installed on the inner side of the top wall of the enclosure 1, efficiently receives heat through the thermal grease 4. The phase change material core 32 inside it begins to change from solid to liquid, absorbing a large amount of latent heat without significantly increasing its own temperature, thereby effectively suppressing the rapid rise in temperature inside the upper equipment mounting cavity 101 and preventing the control circuit board from aging faster due to overheating. At the same time, the air inside the upper equipment mounting cavity 101 expands due to heat, and some of the humid air is slowly forced into the lower humidity regulating cavity 102 through the ventilation micropores 201 on the partition 2, where water molecules are absorbed by the humidity buffer material 53.

[0039] As night falls, the ambient temperature drops sharply below 30°C, and the outer wall of the enclosure 1 cools rapidly due to radiative cooling. Without the phase change heat storage unit 3, the air inside the enclosure would cool quickly below the dew point, causing condensation on the inner wall and component surfaces. However, in this structure, the phase change material core 32, due to its temperature being below the phase change point, begins a liquid-solid phase change, releasing the latent heat stored during the day. This significantly slows down the cooling rate inside the upper equipment mounting cavity 101, maintaining the inner wall temperature at least 2°C above the dew point, fundamentally inhibiting direct condensation. Simultaneously, the air volume inside the upper equipment mounting cavity 101 contracts, creating a slight negative pressure. This causes the relatively dry air, after moisture absorption treatment, in the lower humidity regulating cavity 102 to flow back to the upper equipment mounting cavity 101 through the ventilation micropores 201, achieving a dynamic balance of internal humidity.

[0040] When encountering sudden rainfall or typhoon weather, the outer wall of the housing 1 is rapidly cooled by rainwater, and the instantaneous temperature difference in some areas may exceed 20°C. At this time, although the phase change heat storage unit 3 can buffer the overall temperature drop, individual metal components such as terminal blocks may still drop below the dew point first due to their low heat capacity, forming trace amounts of condensate. After these condensate droplets adhere to the upper surface of the partition 2, they collect along the guide channel 202 under gravity and capillary action, and finally reach the drain micropores 203 spaced apart at the bottom of the channel, entering the lower humidity regulating chamber 102 and being captured by the humidity buffer material 53. Because these particles have a hierarchical pore structure, they can efficiently lock in liquid water and convert it into bound water, preventing secondary evaporation.

[0041] Throughout the temperature and humidity cycle, the temperature gradient blocking layer 9 on the inner sidewall of the enclosure 1 plays a crucial role in thermal insulation. In its three-layer composite structure, the outer aluminum foil 93 reflects external radiant heat, the middle closed-cell foamed polyethylene 92 significantly reduces the heat conduction rate, and the inner polyimide film 91 ensures electrical insulation performance even under localized high temperatures. This design delays the transmission of severe temperature fluctuations from the outer wall of the enclosure 1 to its interior, providing a sufficient response window for the phase change heat storage unit 3 and the humidity buffer unit 5.

[0042] If the phase change material core 32 undergoes minor thermal decomposition to generate gas after thousands of thermal cycles, the internal pressure of the metal encapsulation shell 31 gradually increases. When the pressure reaches 0.05 MPa, the stainless steel ball in the one-way exhaust valve 34 overcomes the spring preload and is pushed open, allowing the gas to be discharged through the 2 mm valve seat. After the pressure drops back to normal, the spring automatically resets and seals the valve port, ensuring that the long-term airtightness of the system remains unaffected.

[0043] In summary, through a multi-level collaborative mechanism including the phase change heat storage unit 3, humidity buffer unit 5, flow guide trough 202 and drainage micropore 203, and temperature gradient blocking layer 9, this invention achieves passive and adaptive regulation of the temperature and humidity environment inside the box without external energy input. This effectively solves the long-standing problem of condensation in metal operating mechanism boxes in harsh outdoor environments and ensures the reliable operation of core components such as the opening and closing mechanism and control circuit.

[0044] To better verify the impact of material selection for the phase change heat storage unit and humidity buffer unit on the overall anti-condensation performance of this invention, the following comparative examples and specific embodiments are provided. All embodiments and comparative examples are based on the same housing structure, with only the phase change material in the phase change heat storage unit and the adsorption material in the humidity buffer unit being changed, and are tested under simulated harsh outdoor temperature and humidity cycling conditions.

[0045] In Example 1, in the phase change heat storage unit 3, the phase change material core 32 is a decanoic acid-lauric acid eutectic mixture with a mass ratio of 65:35, a melting point of 40℃±1℃, and a latent heat of phase change of 180kJ / kg; in the humidity buffer unit 5, the humidity buffer material 53 is a modified aluminosilicate particle with a micropore diameter of 0.5nm, a mesopore diameter of 3nm, and a particle size of 3mm, and is hydrophobically treated, with a static moisture absorption capacity of 28g / 100g under the conditions of temperature 25℃ and relative humidity 80%.

[0046] In Example 2, in the phase change heat storage unit 3, the phase change material core 32 is a myristic acid-palmitic acid eutectic mixture with a mass ratio of 58:42, a melting point of 41℃±1℃, and a latent heat of phase change of 190kJ / kg; in the humidity buffer unit 5, the humidity buffer material 53 is a modified molecular sieve particle with a micropore size of 0.45nm, a mesopore size of 2.5nm, and a particle size of 2.5mm, and is hydrophobically treated, with a static moisture absorption capacity of 30g / 100g under the conditions of temperature 25℃ and relative humidity 80%.

[0047] In Comparative Example 1, the phase change heat storage unit 3 was replaced with a conventional paraffin-based phase change material with a melting point of 48℃±2℃, and the rest of the structure was the same as in Example 1; the humidity buffer unit 5 was the same as in Example 1.

[0048] In Comparative Example 2, the phase change heat storage unit 3 was removed, and only an aluminum heat sink of the same volume was installed on the top of the housing 1; the humidity buffer unit 5 was replaced with ordinary silica gel desiccant with a particle size of 3-5mm, which was not modified.

[0049] The following performance tests were conducted on Examples 1-2 and Comparative Examples 1-2 of this application.

[0050] The operating mechanism boxes of each embodiment and comparative example were placed in a temperature and humidity cycling test chamber to simulate typical outdoor climate conditions: daytime temperature 35℃, relative humidity 85%, nighttime temperature 15℃, relative humidity 95%, with a cycle period of 24 hours, and continuous operation for 30 days. The highest / lowest temperature and relative humidity changes inside the chamber were recorded daily, and the condensation on the inner wall and component surface was checked. The test results are shown in Table 1.

[0051] Table 1 Summary of Test Results

[0052]

[0053] Wherein, temperature difference suppression rate = (day and night temperature difference in the untreated chamber) (Day-night temperature difference inside the box under this solution) ÷ Day-night temperature difference inside the box without measures × 100%;

[0054] Humidity fluctuation suppression rate = (humidity fluctuation amplitude in the untreated chamber) (Humidity fluctuation amplitude inside the box under this plan) ÷ Humidity fluctuation amplitude inside the box without measures × 100%;

[0055] Condensation inhibition rate = (Number of days with condensation without measures) (Number of days with condensation occurring under this plan) ÷ Number of days with condensation occurring without measures × 100%.

[0056] Both Examples 1 and 2 demonstrated excellent temperature and humidity synergistic regulation capabilities, significantly reducing temperature and humidity fluctuations within the chamber and essentially eliminating condensation. Example 1 was selected as the optimal example because its phase change temperature is closer to the common high-temperature range outdoors, and its humidity buffer material has a suitable pore size distribution, resulting in slightly better performance in heat and moisture exchange kinetics than Example 2.

[0057] In Comparative Example 1, the high melting point of the paraffin phase change material resulted in a delayed start-up of daytime heat absorption, insufficient heat release at night, reduced temperature buffering effect, and a significant decrease in condensation inhibition rate.

[0058] In Comparative Example 2, after the phase change heat storage unit was removed, the temperature inside the chamber completely followed the external fluctuations, and the humidity regulation relied solely on ordinary silica gel. Its moisture absorption capacity is low and it lacks a graded pore structure, making it unable to achieve rapid adsorption and stable storage of moisture. The condensation inhibition rate dropped significantly, and ordinary silica gel is prone to saturation and failure under high temperature and high humidity.

[0059] The fatty acid-based phase change material (melting point 38℃-42℃) selected in this invention, combined with modified aluminosilicate particles with a hierarchical porous structure, forms a highly efficient and stable passive temperature and humidity synergistic regulation system under specific structural conditions. Comparative examples show that if the material selection deviates from the scope of this invention, the overall anti-condensation performance significantly decreases. This further confirms the inventiveness of this invention at the material level and its outstanding advantage of achieving long-lasting anti-condensation without external energy input.

[0060] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A waterproof pole-mounted circuit breaker, comprising an arc-extinguishing chamber, an operating mechanism box, a current transformer, a voltage transformer, and a disconnecting switch, wherein the operating mechanism box comprises a housing (1), characterized in that, A partition (2) is horizontally fixed to the inner side of the box (1). The partition (2) divides the inner side of the box (1) into an upper equipment installation cavity (101) and a lower humidity regulation cavity (102). A phase change heat storage unit (3) is installed on the top of the upper equipment installation cavity (101). Thermal grease (4) is provided between the phase change heat storage unit (3) and the box (1). A plurality of ventilation microholes (201) are evenly distributed on the partition (2). The upper equipment installation cavity (101) and the lower humidity regulation cavity (102) are connected through the ventilation microholes (201). A humidity buffer unit (5) is provided in the lower humidity regulation cavity (102). The phase change heat storage unit (3) includes a metal encapsulation shell (31), a phase change material core (32), and heat-conducting fins (33). The top of the upper equipment mounting cavity (101) is fixedly provided with a mounting boss (6). The top surface of the metal encapsulation shell (31) is mounted on the mounting boss (6) by screws (7). The phase change material core (32) is a fatty acid phase change material with a melting point of 38°C to 42°C. The heat-conducting fins (33) are aluminum sheets. Multiple heat-conducting fins (33) are vertically welded to the bottom of the metal encapsulation shell (31). The humidity buffer unit (5) includes a box body (51), and a plurality of positioning rings (8) are provided on the side wall of the lower humidity regulating cavity (102). A positioning block (52) is provided on the side wall of the box body (51) corresponding to the positioning rings (8). The inner cavity of the box body (51) is filled with a humidity buffer material (53), and the humidity buffer material (53) has reversible moisture absorption and release characteristics. The humidity buffer material (53) is a modified aluminosilicate particle with a particle size of 2 mm to 4 mm. The surface of the modified aluminosilicate particle is hydrophobically treated and has a hierarchical pore structure inside. The micropore size is 0.4 nm to 0.6 nm and the mesopore size is 2 nm to 5 nm.

2. The waterproof pole-mounted circuit breaker according to claim 1, characterized in that, The metal encapsulation housing (31) is provided with a one-way exhaust valve (34) on its side, which is used to exhaust the gas inside the metal encapsulation housing (31).

3. The waterproof pole-mounted circuit breaker according to claim 1, characterized in that, The inner side wall of the box (1) is provided with a temperature gradient blocking layer (9). The temperature gradient blocking layer (9) includes a polyimide film (91), a closed-cell foamed polyethylene (92) and an aluminum foil (93) arranged sequentially from the inside to the outside. The polyimide film (91), the closed-cell foamed polyethylene (92) and the aluminum foil (93) are bonded to the inner surface of the side wall of the box (1) after being composited by a hot pressing process.

4. The waterproof pole-mounted circuit breaker according to claim 1, characterized in that, The upper surface of the partition (2) is provided with multiple guide grooves (202), and the bottom of the guide grooves (202) is provided with multiple downward-through drainage microholes (203), and the drainage microholes (203) are set directly opposite the humidity buffer unit (5).

5. The waterproof pole-mounted circuit breaker according to claim 1, characterized in that, The partition (2) is made of a high thermal conductivity metal. A plurality of vertically downward thermally conductive fins (10) are fixed on the lower surface of the partition (2). The thermally conductive fins (10) extend to the lower humidity regulating cavity (102) and are located on the side of the humidity buffer unit (5).

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