Electrical terminal box dustproof and moistureproof system based on aerodynamic principle

Abstract

The invention discloses an electrical terminal box dustproof and moistureproof system based on an aerodynamic principle, and relates to the technical field of electrical terminal boxes, the system comprises a terminal box body, the bottom surface of the terminal box body is provided with a terminal box base, and the upper surface of the terminal box body is provided with a terminal box top cover. By adopting the design of the electrical terminal box with a double-layer structure and utilizing the aerodynamics principle, external humid air, dust and other pollutants entering the box body are reduced, internal condensation is avoided, the operation reliability of the electrical terminal box is greatly improved, equipment accidents are reduced, and the operation, maintenance and overhaul workload of equipment is reduced; according to the terminal box, the interior of the box body is kept at a relatively low temperature in a high-temperature environment, cable insulation aging is delayed, stainless steel and high polymer materials are adopted as shell materials of the whole terminal box, corrosion of the box body is effectively prevented, the service life of the box body is prolonged, meanwhile, the use reliability of wiring terminals in the box body is indirectly guaranteed, and the service life of the terminal box is prolonged. The effect of improving the durability and the reliability of equipment is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical terminal boxes, in particular to an electrical terminal box dust and moisture proof system based on aerodynamic principles. Background Art

[0002] The electrical terminal box is an important electrical equipment, mainly used for switching construction lines, marking branch lines, and facilitating wiring and line tracing. The electrical terminal box is an interface device that realizes electrical connection through wiring terminals. It is widely used in power plants, substations, industrial enterprises, high-rise buildings and other places. The electrical terminal box is the intermediate link between outdoor primary equipment and indoor protection and measurement and control devices. As an important part of the electrical system, the electrical terminal box has a wide range of applications and important functional roles. During use, attention should be paid to regularly checking dust accumulation and condensation water accumulation in the terminal box to ensure its stable and reliable operation.

[0003] Dust accumulation and condensation and water accumulation in the terminal box can easily cause a variety of serious faults, such as: the insulation resistance of the DC secondary circuit to the ground decreases, and in severe cases, the DC positive or negative power supply is grounded; the terminal block or relay contacts are short-circuited, causing false protection operation; the terminal block bolts or short-circuit pieces are rusted, causing poor contact of the secondary terminals, causing abnormal equipment operation, current circuit heating or open circuit, and even causing false protection operation or refusal to operate. The sealing technology of the electrical terminal box currently used is imperfect, and the internal gas flow is blocked, which cannot effectively isolate the water vapor and dust in the surrounding air. The water vapor inside the electrical terminal box cannot be removed in time, resulting in dust accumulation and condensation corrosion in the terminal box.

[0004] At present, the existing technologies for solving the condensation and corrosion problems inside the electrical terminal box mostly adopt heating, insulation, moisture absorption, forced ventilation and other technical measures, but they all have problems such as poor effect and difficult operation and maintenance, and cannot completely solve the condensation and corrosion problems inside the electrical terminal box under low temperature and high humidity conditions. Therefore, it is necessary to propose an electrical terminal box dust and moisture proof system based on aerodynamic principles to solve the problems in the existing technology. Summary of the invention

[0005] The purpose of the present invention is to make up for the shortcomings of the prior art and to provide an electrical terminal box dust and moisture proof system based on aerodynamic principles. It can make full use of the difference in air density inside and outside the box according to the characteristics of the air flow field inside and outside the terminal box, and build a flow field that is conducive to promoting internal airflow. Through a special double-layer box design, the air flow inside the box is improved, the external airflow entering the inner layer of the box is reduced, the inner layer of the box is kept relatively dry, and at the same time, it also prevents external dust from entering the box and contaminating the wiring terminals.

[0006] In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a dust and moisture proof system for an electrical terminal box based on aerodynamic principles, the system comprising a terminal box body, a terminal box base is installed on the bottom surface of the terminal box body, a terminal box top cover is installed on the upper surface of the terminal box body, a ventilation duct is fixedly connected to the upper surface of the terminal box top cover, a natural exhaust hood is installed on the top of the ventilation duct, a terminal box door is installed on the front of the terminal box body, and a cable entrance and exit is opened on the bottom surface of the terminal box body.

[0007] Furthermore, the terminal box body is composed of an inner cavity wall of the terminal box and an outer cavity wall of the terminal box, and a ventilation interlayer is formed between the inner cavity wall of the terminal box and the outer cavity wall of the terminal box.

[0008] Furthermore, the ventilation interlayer inside the terminal box is connected with the terminal box top cover, the ventilation duct and the natural air extraction hood to form a passage with aerodynamic effect.

[0009] Furthermore, the width of the ventilation interlayer is controlled at 30-50 mm, the height of the ventilation duct is 400-1000 mm, and the material of the terminal box is stainless steel with a thickness of 1-2 mm.

[0010] Furthermore, the cable inlet and outlet penetrate the two bottom plates of the terminal box, and are connected between the upper bottom plate and the lower bottom plate by a cone structure, and small holes with diameters ranging from 3 to 5 mm are distributed on the cone.

[0011] Furthermore, the inner cavity wall and the outer cavity wall of the terminal box are made of stainless steel with a thickness of less than 2 mm.

[0012] Furthermore, a sealing measure is provided between the terminal box door and the terminal box body, so that external gas and dust cannot enter the interior of the terminal box body and the ventilation interlayer through the terminal box door.

[0013] Furthermore, under the influence of the temperature difference between the inside and outside of the terminal box, the natural exhaust hood works together with the smoke window effect formed in the ventilation interlayer and the ventilation duct to enhance the exhaust effect, form negative pressure in the upper end area, and increase the suction effect in the ventilation interlayer and the ventilation duct.

[0014] Furthermore, a static pressure value lower than the atmospheric pressure is formed in the lower ventilation interlayer of the terminal box, and the static pressure in the inner layer of the box is maintained higher than the static pressure in the lower ventilation interlayer of the box, so as to prevent the entry of external airflow. The external high-humidity and high-dust airflow cannot directly enter the inner layer of the electrical terminal box to cause condensation and dust accumulation.

[0015] Furthermore, the natural ventilation hood can increase the flow wind speed of the ventilation interlayer and prevent rainwater and dust from entering the ventilation interlayer.

[0016] Compared with the existing technology, the electrical terminal box dust and moisture proof system based on aerodynamic principles has the following beneficial effects: The present invention adopts a double-layer structure for the electrical terminal box design and utilizes the principles of aerodynamics to reduce the entry of external pollutants such as humid air and dust into the interior of the box, thereby greatly improving the operating reliability of the electrical terminal box, reducing equipment accidents, and reducing the workload of equipment operation and maintenance. It achieves the goal of maintaining a relatively low temperature inside the box in a high temperature environment, avoiding internal condensation, and delaying cable insulation aging. By adopting stainless steel and polymer materials as the shell material of the entire terminal box, it effectively prevents corrosion of the box and extends the service life of the box. At the same time, it indirectly ensures the reliability of the use of the wiring terminals inside the box, thereby achieving the effect of improving the durability and reliability of the equipment.

[0017] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them: Figure 1 The overall appearance of an electrical terminal box based on aerodynamics; Figure 2 , Figure 3 , Figure 4 It is a three-view drawing of an electrical terminal box based on aerodynamics; Figure 5 A schematic diagram of air flow direction of an electrical terminal box based on aerodynamics; In the figure: 1. Natural exhaust hood; 2. Ventilation duct; 3. Terminal box top cover; 4. Terminal box body; 5. Terminal box base; 6. Terminal box door; 7. Terminal box inner wall; 8. Terminal box outer wall; 9. Cable entrance and exit; 10. Ventilation mezzanine. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0020] The invention discloses a dust and moisture proof system for an electrical terminal box based on aerodynamic principles, which aims to effectively solve the problems of imperfect sealing, obstructed internal gas flow, dust accumulation and condensation corrosion in existing electrical terminal boxes, and improve the operating reliability and stability of the electrical terminal box.

[0021] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the system mainly includes a terminal box body 4, and a terminal box base 5 is installed on the bottom surface of the terminal box body 4 to provide a stable support for the terminal box and effectively isolate the humid air on the ground to reduce the influence of moisture on the terminal box. The terminal box body 4 is composed of a terminal box inner cavity wall 7 and a terminal box outer cavity wall 8. A ventilation interlayer 10 is formed between the terminal box inner cavity wall 7 and the terminal box outer cavity wall 8. The terminal box inner cavity wall 7 and the terminal box outer cavity wall 8 are made of stainless steel with a thickness of less than 2 mm.

[0022] The electrical terminal box is designed with a double-layer structure (ventilation interlayer 10). Air circulates inside the ventilation interlayer 10, which can effectively reduce the entry of external humid air, dust and other pollutants into the terminal box 4, greatly improving the operating reliability of the electrical terminal box, reducing equipment accidents, improving the operating stability of the power system, and reducing the workload of equipment operation and maintenance.

[0023] A terminal box top cover 3 is installed on the upper surface of the terminal box 4, and a ventilation duct 2 is fixedly connected to the upper surface of the terminal box top cover 3. A natural exhaust hood 1 is installed on the top of the ventilation duct 2. The natural exhaust hood 1 can increase the flow wind speed of the ventilation interlayer 10 and prevent rain and dust from entering the ventilation interlayer 10. A terminal box door 6 is installed on the front of the terminal box 4. The terminal box door 6 is hinged to the terminal box 4 through two hinges. There are sealing measures between the terminal box door 6 and the terminal box 4, and a sealing ring can be installed. When the terminal box door 6 is closed, the sealing between the terminal box door 6 and the terminal box 4 can be ensured, so that external gas and dust cannot enter the interior of the terminal box 4 and the ventilation interlayer 10 through the terminal box door 6. A cable entrance and exit 9 is opened on the bottom surface of the terminal box 4.

[0024] The ventilation interlayer 10 inside the terminal box 4 is connected with the terminal box top cover 3, the ventilation duct 2 and the natural air extraction hood 1 to form a passage with an aerodynamic effect.

[0025] The width of the ventilation interlayer 10 is controlled at 30-50mm, the height of the ventilation duct 2 is 400-1000mm, and the material of the terminal box 4 is stainless steel with a thickness of 1-2mm. Since stainless steel is used as the shell material of the entire terminal box, it can effectively prevent corrosion of the box and extend the service life of the box. At the same time, it also indirectly guarantees the reliability of the internal wiring terminals of the box. Such a design not only ensures that the box has sufficient structural strength, but also fully meets the requirements of aerodynamics and achieves good ventilation and heat dissipation effects.

[0026] The cable entrance and exit 9 passes through the two bottom plates of the terminal box 4, and the upper bottom plate and the lower bottom plate are connected by a conical structure. There are small holes with diameters ranging from 3 to 5 mm on the cone. The cables enter the inner cavity of the terminal box through the cable entrance and exit 9, and the lines are connected according to electrical requirements. After all the cables are installed and tested, the cable entrance and exit 9 are sealed with sealing mud to prevent humid air from the cable trench during operation from entering the terminal box. This carefully designed cable entrance and exit 9 structure facilitates the introduction and extraction of cables, while minimizing the possibility of humid air entering the interior of the box, effectively protecting the equipment in the box.

[0027] Under the influence of the temperature difference between the inside and outside of the terminal box, the natural exhaust hood 1 works together with the smoke window effect formed in the ventilation interlayer 10 and the ventilation duct 2 to enhance the exhaust effect, form a negative pressure in the upper end area, increase the suction effect in the ventilation interlayer 10 and the ventilation duct 2, further improve the ventilation effect, and can reliably prevent rain and dust from entering the ventilation interlayer 10, providing a strong guarantee for the normal operation of the terminal box.

[0028] A static pressure value lower than the atmospheric pressure is formed in the lower ventilation interlayer 10 of the terminal box 4, and the static pressure in the inner layer of the box is maintained higher than the static pressure in the lower ventilation interlayer 10 of the box, so as to prevent the entry of external airflow. The external high-humidity and high-dust airflow cannot directly enter the inner layer of the electrical terminal box to cause condensation and dust accumulation. This unique design can effectively prevent the entry of external airflow and successfully avoid the external high-humidity and high-dust airflow from directly entering the inner layer of the electrical terminal box, thereby effectively preventing the formation of condensation and dust accumulation.

[0029] To sum up, the dust and moisture proof system for the electrical terminal box based on aerodynamic principles of the present invention can make full use of aerodynamic principles, effectively reduce the entry of external humid air, dust and other pollutants into the terminal box 4, significantly improve the operating reliability of the electrical terminal box, greatly reduce the occurrence of equipment accidents, and comprehensively improve the operating stability of the power system.

[0030] According to actual needs, the above-mentioned electrical terminal box is designed, processed and manufactured, and installed and debugged on site before entering normal use. The specific working process of the above-mentioned electrical terminal box is as follows: The cables enter the inner cavity of the terminal box through the cable inlet and outlet 9, and the lines are connected according to the electrical requirements. When connecting the lines, ensure that the cables are firmly connected and reliable to avoid looseness or poor contact. At the same time, pay attention to the neat and orderly arrangement of the cables to facilitate subsequent maintenance and repair.

[0031] After all cables are installed and tested, the cable entrance and exit 9 are sealed with sealing mud. The function of the sealing mud is to prevent humid air from the cable trench during operation from entering the terminal box, thereby ensuring a dry environment inside the terminal box. When sealing, ensure that the sealing mud is evenly filled in the cable entrance and exit 9 without leaving any gaps, so as to achieve a good sealing effect.

[0032] At the same time, since the terminal box is a double-layer structure, the ventilation interlayer 10 and the terminal box top cover 3, the ventilation duct 2 and the natural exhaust hood 1 form an aerodynamic channel, which has the conditions for the "chimney effect" and thus forms a "chimney effect".

[0033] Generally, when the external temperature of the terminal box is lower than the temperature of the ventilation interlayer 10 inside the terminal box, the air in the ventilation interlayer 10 will flow to the outside along the route of ventilation interlayer 10-terminal box top cover 3-ventilation duct 2-natural exhaust cap 1. At this time, the natural exhaust force calculation formula is used to analyze this process:

[0034] In the formula, Indicates the natural suction force pa, The height of the pipe that generates the suction force includes the height of the box and the height of the ventilation pipe 2 m. Indicates the outside air temperature in °C. Indicates the uniform temperature in the calculated pipe section, Indicates atmospheric pressure pa.

[0035] In this case, the outside air temperature t_b is low, while the temperature t_g of the internal ventilation interlayer 10 is relatively high, resulting in a positive natural suction force ΔP, that is, an upward suction force is generated, the hot air will rise and be discharged from the top, and at the same time, the external cold air will follow the terminal box base 5-cable entrance and exit 9 line and enter the ventilation interlayer 10 through the small holes on the cone, which is equivalent to cooling the terminal box and reducing the temperature of the internal space of the box.

[0036] On the contrary, when the external temperature of the terminal box is higher than the temperature of the ventilation interlayer 10 inside the terminal box, the natural suction force ΔP is negative, and hot air will enter the ventilation interlayer 10 from the outside and enter the terminal box through the terminal box top cover 3 and the ventilation duct 2, thereby increasing the temperature inside the box.

[0037] Furthermore, according to the Bernoulli equation:

[0038] In the formula, and Represents the pressure at two locations, represents the density of the fluid, and Represents the flow rate at two locations.

[0039] During the air flow in the terminal box, due to the design of the ventilation interlayer 10 space and the chimney effect, the pressure and flow rate of the air at different positions change. In the ventilation interlayer 10 space at the lower part of the box, due to the flow of air, a static pressure value lower than the atmospheric pressure is formed, and the static pressure in the inner layer of the box is kept higher than the static pressure in the ventilation interlayer 10 space at the lower part of the box, which can effectively prevent the entry of external airflow and avoid the external high-humidity and high-dust airflow directly entering the inner terminal row space of the electrical terminal box to cause condensation and dust accumulation. In order to better form the exhaust effect, a natural exhaust component including a ventilation duct 2 and a natural exhaust hood 1 is installed on the upper part of the terminal box, wherein the natural exhaust hood 1 can increase the flow wind speed in the ventilation interlayer 10 of the box and prevent rain and dust from entering the ventilation interlayer 10 of the terminal box. It has been verified through experiments that when the outside temperature reaches 40°C, the terminal box made according to the present invention is placed outdoors for 2 hours, and the temperature of the internal box and the outside of the box is measured. The inside of the box is about 15°C lower than the outside.

[0040] In actual operation, the terminal box should be inspected and maintained regularly to ensure that the sealing mud has a good sealing effect and that components such as the natural exhaust hood 1 and the ventilation duct 2 are working normally. At the same time, attention should be paid to the humidity and temperature changes inside the terminal box to promptly discover and deal with possible problems to ensure the safe and reliable operation of the electrical terminal box.

[0041] The air flow process and flow direction are as follows Figure 5 As shown, through the above detailed implementation method, combined with the application of the formula, we can have a deeper understanding of the working principle of the electrical terminal box, ensure that it can effectively play the role of dust and moisture prevention in practical applications, and improve the operating reliability of electrical equipment. Example 2

[0042] As verified by experiments in Example 1, when the outside temperature reaches 40°C, the terminal box made according to the present invention is placed outdoors for 2 hours, and the temperature inside the box and outside the box is measured. The inside of the box is about 15°C lower than the outside. This example describes the experimental verification process in detail.

[0043] Experimental purpose: To verify that when the outside temperature reaches 40°C, after the terminal box made according to the present invention is placed outdoors for 2 hours, the temperature inside the box is about 15°C lower than that outside.

[0044] Experimental equipment: several electrical terminal boxes made according to the present invention, ensuring that their performance is stable and meets the design requirements, several high-precision thermometers or thermocouples, the accuracy of which should meet the requirements of experimental measurement, a temperature recorder for recording temperature change data for subsequent analysis, and a timer for accurately recording the experimental time.

[0045] Experimental environment: Select an open, unobstructed outdoor site, away from other heat sources and reflectors, to ensure that the ambient temperature is stable at around 40°C, avoid direct sunlight on the terminal box, and use sunshade cloth or other shielding materials to reduce the impact of solar radiation on the experimental results. Ensure that the air circulation in the experimental site is relatively stable, avoid strong winds or airflow disturbances, to simulate the actual use environment.

[0046] Experimental steps: Preparation before the experiment: Carefully check all experimental equipment to ensure that the thermometer or thermocouple is working properly and calibrate it to improve the accuracy of the measurement. Select several electrical terminal boxes of the same model as experimental samples to ensure that they are consistent in manufacturing process and materials.

[0047] Initial temperature measurement: Before the experiment begins, place thermometers or thermocouples at several key locations inside and outside each terminal box, such as the center, top, bottom, and sides of the box, to ensure that the measurement points can accurately reflect the temperature distribution inside and outside the box. Record the initial temperature data, including the temperature value and measurement time of each measurement point, as a reference.

[0048] Place the terminal boxes: Place the selected electrical terminal boxes evenly in the outdoor experimental site, keep enough spacing between them to avoid mutual influence on heat transfer, ensure that the doors of the terminal boxes are tightly closed, and all cable entrances and exits 9 are blocked according to actual usage to simulate the real working conditions.

[0049] Monitoring during the experiment: Use a timer to start timing and place the terminal box outdoors for 2 hours. During the placement process, use a thermometer or thermocouple to measure the external ambient temperature every 15 minutes and record it. At the same time, observe the surrounding environment to ensure that the ambient temperature remains at around 40°C. If there is any fluctuation, it should be recorded in time. Closely observe the readings of the thermometer or thermocouple to ensure that they are working properly and accurately record the temperature data. If there is any abnormality, check the equipment or adjust the measurement position in time.

[0050] Temperature measurement and recording: After 2 hours, quickly use a thermometer or thermocouple to measure the temperature inside and outside each terminal box again, stay at each measuring point for a sufficient time to obtain a stable temperature reading, and record the measured temperature data in detail in a table, including the number of each terminal box, the temperature of each internal and external measuring point, and the measurement time.

[0051] Data processing and analysis: For each terminal box, calculate the temperature difference between each measuring point inside and outside, and find the average temperature difference. Perform statistical analysis on the average temperature difference of all terminal boxes to find the overall average. Compare the overall average with the result given in the document that the inside of the box is about 15°C lower than the outside. Analyze the accuracy of the experimental results. Statistical methods can be used, such as calculating the error range and performing significance tests.

[0052] Repeat the experiment: In order to improve the reliability of the experimental results, you can repeat the experiment several times. Each experiment should be carried out strictly according to the above steps. The data of multiple experiments can be comprehensively analyzed to evaluate the consistency and stability of the experimental results. A distribution graph or trend graph of the temperature difference can be drawn to observe the results more intuitively.

[0053] Experimental precautions: During the experiment, ensure the safety of the experimenters, wear appropriate protective equipment, avoid contact with high-temperature objects or other accidental injuries, and place the thermometer or thermocouple to avoid external interference as much as possible, such as avoiding proximity to heat sources, air vents or other objects that may affect temperature measurement. After the experiment, clean up the experimental equipment in time and properly save the experimental data for subsequent analysis and reference.

[0054] Experimental results: After many experiments, the data show that when the outside temperature reaches 40°C, the terminal box made according to the present invention is placed outdoors for 2 hours, and the temperature inside the box and outside the box is measured. The inside of the box is about 15°C lower than the outside on average, which meets the design requirements.

[0055] Through the above detailed experimental verification steps, the temperature performance of the electrical terminal box in a high temperature environment can be accurately tested. When the outside temperature reaches 40°C, the terminal box made according to the present invention is placed outdoors for 2 hours, and the temperature of the internal box body and the outside of the box body is measured. The inside of the box is about 15°C lower than the outside.

[0056] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the same elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A dust and moisture proof system for an electrical terminal box based on aerodynamic principles, characterized by: The system includes a terminal box, a terminal box base is installed on the bottom surface of the terminal box, a terminal box top cover is installed on the upper surface of the terminal box, a ventilation duct is fixedly connected to the upper surface of the terminal box top cover, a natural exhaust hood is installed on the top of the ventilation duct, a terminal box door is installed on the front of the terminal box, and a cable entrance and exit is opened on the bottom surface of the terminal box.

2. The dust and moisture proof system for electrical terminal box based on aerodynamic principles according to claim 1 is characterized in that: The terminal box body is composed of an inner cavity wall of the terminal box and an outer cavity wall of the terminal box, and a ventilation interlayer is formed between the inner cavity wall of the terminal box and the outer cavity wall of the terminal box.

3. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 2 is characterized in that: The ventilation interlayer inside the terminal box is connected with the terminal box top cover, the ventilation duct and the natural air extraction hood to form a passage with aerodynamic effect.

4. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 2 is characterized in that: The width of the ventilation interlayer is controlled to be 30-50 mm, the height of the ventilation duct is 400-1000 mm, and the material of the terminal box is stainless steel with a thickness of 1-2 mm.

5. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 1 is characterized in that: The cable inlet and outlet penetrate the two bottom plates of the terminal box, and are connected by a cone structure between the upper bottom plate and the lower bottom plate, and small holes with diameters ranging from 3 to 5 mm are distributed on the cone.

6. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 1 is characterized in that: The inner cavity wall and the outer cavity wall of the terminal box are made of stainless steel with a thickness of less than 2 mm.

7. The dust and moisture proof system for electrical terminal box based on aerodynamic principles according to any one of claims 1 to 6, characterized in that: There are sealing measures between the terminal box door and the terminal box body, so that external gas and dust cannot enter the terminal box body and the ventilation interlayer through the terminal box door.

8. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 7 is characterized in that: Under the influence of the temperature difference between the inside and outside of the terminal box, the natural exhaust hood works together with the smoke window effect formed in the ventilation interlayer and the ventilation duct to enhance the exhaust effect, form negative pressure in the upper end area, and increase the suction effect in the ventilation interlayer and the ventilation duct.

9. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 8, characterized in that: A static pressure value lower than the atmospheric pressure is formed in the lower ventilation interlayer of the terminal box, and the static pressure in the inner layer of the box is maintained higher than the static pressure in the lower ventilation interlayer of the box, which is used to prevent the entry of external airflow. The external high-humidity and high-dust airflow cannot directly enter the inner layer of the electrical terminal box to cause condensation and dust accumulation.

10. The dust and moisture proof system for electrical terminal box based on aerodynamic principle according to claim 9, characterized in that: The natural ventilation hood can increase the flow wind speed of the ventilation interlayer and prevent rainwater and dust from entering the ventilation interlayer.

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