| With the continuous improvement of social production level and people’s living quality,power system is also experiencing rapid development.Safe and stable operation of power equipment is of great practical significance to maintain the reliability and continuity of power supply.High voltage switchgear is an important integrated electrical equipment which plays a key control and protection role in the power system.Fire accidents pose a great threat to its safety and economy.However,due to the limitations of technical means and fire extinguishing materials,electric power workers have been unable to find an effective solution.The development of thermal aerosol fire extinguishing technology provides more possibilities for dealing with live fire in high-voltage switchgear.In this paper,by combining theoretical analysis,simulation calculation and experimental demonstration,a detailed research work is carried out around the thermal aerosol fire extinguishing technology according to the fire characteristics of high-voltage switchgear.The main research contents and achievements are as follows:1)This paper introduces the hierarchical structure of independent compartment of high-voltage switchgear and the actual operating characteristics of high voltage and large current carried by primary equipment in the cabinet.Through analyzing a large number of fire accident cases,it summarizes the five root causes of high-voltage switchgear fire,i.e.excessive resistance fire,leakage fire,overload fire,short circuit fire and environmental factors.2)In order to further explore the heating effect of electric contacts,this paper takes KYN28A-12 type high-voltage switchgear as the goal and simplifies the use of Auto.CAD establishes the three-dimensional model of high-voltage switchgear and obtains the temperature rise data and temperature distribution of 10 k V high-voltage switchgear under normal operation state after reaching steady state by using COMSOL finite element simulation calculation software.It proves that the serious heat of electric contact area is the main reason for large temperature rise of high-voltage switchgear under normal operation state,and points out that in fire extinguishing design,the corresponding measures should be taken:The electric contact area is taken as the key protection object.3)Starting from the differences in chemical composition between K-type aerosol and S-type aerosol,the basic properties of thermal aerosol are comprehensively analyzed,the fire extinguishing mechanism of thermal aerosol is described in detail,and the advantages of thermal aerosol in terms of cleanliness,safety performance and fire extinguishing efficiency are summarized by comparing with traditional fire extinguishing materials.In order to clarify the influence of thermal aerosols on the insulation of live equipment in high-voltage switchgear,this paper carries out power frequency withstand voltage test on 10 k V high-voltage cable sprayed with K-type aerosol.The experimental results show that thermal aerosols will not reduce the insulation strength of equipment,and preliminarily verify the feasibility of application of thermal aerosol fire extinguishing technology in high-voltage switchgear.4)Using K-type aerosol fire extinguishing technology,simulate the real fire scene in KYN28A-12 high-voltage switchgear,carry out the full submergence fire extinguishing experiment of high-voltage switchgear,verify the high efficiency of fire extinguishing by thermal aerosol;carry out the test of thermal aerosol barrier-crossing ability,verify the super-strong diffusion protection ability of thermal aerosol;carry out comprehensive test of starting mode,and screen out fast and sensitive self-extinguishing.Kinem-atic induction heuristics.This paper carries out detailed research and analysis work on automatic fire extinguishing technology of thermal aerosol and live fire scene of high-voltage switch cabinet.The application of automatic fire extinguishing technology of thermal aerosol provides efficient and reliable protection in high-voltage switch cabinet,makes up the shortcomings of traditional fire extinguishing technology and breaks the limitation of selection of fire extinguishing materials.The research has high practical engineering application value and is of great significance to safe operation of high-voltage switchgear and fire protection with electric field. |
