Installation and heat dissipation issues of box type substation.
The space under the foundation of the box type substation equipped with oil immersed transformers cannot be separated. In the event of a transformer fire accident, transformer oil leaks into the space, causing the box type substation to catch fire and resulting in significant losses. The complete set of power distribution equipment is supplied by the manufacturing plant and assembled into a power distribution device after being transported to the site. It divides the main electrical circuit into several units, each unit is a circuit, and the circuit breakers, knife switches, current transformers, voltage transformers, as well as protection, control, measurement and other equipment of each unit are assembled in a whole cabinet. The power device composed of multiple high-voltage switchgear installed in power plants, substations or distribution stations is called a complete distribution device. The space under the installation interval of the transformer should be isolated separately and made into an oil storage tank. In case of oil leakage fault, it should be led into the oil storage tank through the oil guide pipe to prevent the accident from expanding. At the same time, it is strictly prohibited for high and low voltage cables to pass through the oil storage tank, which can effectively prevent fire hazards to other equipment. The cable holes in the box type substation are relatively large and cannot effectively prevent moisture and foreign objects from entering. It is required that the cables entering and leaving the box type substation should be threaded through pipes, and the cable pipes should be sealed. At the same time, the cables should be coiled and placed in the lower space as required. The cable entrance into the foundation of the box type substation should also be properly sealed, especially for cables laid in cable trenches. The entrance of the cable into the foundation of the box type substation should also pay attention to waterproofing, and should be introduced into the foundation of the box type substation along the cable trench.
Some box type substations have construction holes left in their foundations, which cannot be sealed after construction is completed, or the sealing is not tight enough, or foreign objects enter the passage after the sealing facilities are damaged, causing harm to the box type substations. Some box type substations have movable doors under the operation and maintenance station board that allow access to the lower space of the foundation. Construction can be carried out through this area, so that there is no need to reserve construction holes on the foundation of the box type substation, thereby reducing unnecessary hidden dangers. Some box type substations have excessively high foundations, making it inconvenient and unsafe to carry out corresponding operations. Some box type substations have their doors facing the road, making it unsafe for personnel to enter and exit. Therefore, it is not advisable to open the doors of box type substations towards the road. Box type substations with higher foundations should be equipped with corresponding suspension rings for movable platforms, as well as suspension rings for safety belts, and equipped with movable platforms for the maintenance and operation of box type substations.
Heat dissipation is one of the main problems in existing box type substations, along with ventilation and dust prevention issues. These three problems interact and constrain each other. The polysilicon ingot casting furnace is the key equipment for polysilicon manufacturing in the complete set of power equipment. The stability of its process flow, the stability and progressiveness of equipment control are directly related to whether qualified silicon ingots can be produced, and the qualified silicon ingots directly determine the photoelectric conversion efficiency of cells made of silicon chips. Low voltage distribution equipment for polycrystalline silicon ingots is widely used in engineering applications, mainly due to the use of AC induction heating for melting. The main reason is that through AC disturbance stirring, the growth of grains is continuously interrupted, causing the grains to become small and polycrystalline, resulting in grain refinement. Temperature rise is caused by the transfer of solar radiation heat from the box to the inside of the box, as well as the heating of transformers, compensating capacitors, and other components inside the box. Excessive temperature rise inside the box can affect the normal operation of high and low voltage equipment and components, and it is necessary to lower the temperature. It is necessary to strengthen ventilation for heat dissipation, which can lead to safety protection and dust prevention issues. In most parts of our country, summer is relatively hot and the temperature is high. Due to the compact structure of the box type station and the small volume inside the transformer, the temperature of the transformer is very high. In addition, the transformer generates a large amount of heat during operation. At this time, it is difficult to meet the requirements for heat dissipation through natural ventilation. Sometimes the indoor temperature even exceeds 50 ℃, which seriously increases the loss and failure rate of the operating equipment. If the box door is opened for heat dissipation, dust and dirt can easily enter, and a dedicated person should be assigned to guard and ensure safety.
In summary, box type substations have been increasingly widely used in China's rapidly developing economy today. However, due to their relatively short introduction and rapid development, there are still some problems and shortcomings. Continuously identifying and improving from design, installation, and other aspects will enable box type substations to be better applied and contribute to the development of the power industry.
