Design And Optimization Of Mine Flameproof Soft Starter

Flameproof enclosure has been widely used in coal mines and a variety of industrial premises,usually installed in the interior of a number of AC or DC control equipment,such as inverter,soft starter,etc..The electrical equipment installed in the flameproof enclosure,can effectively prevent the circuit system of the shell due to gas electric spark fault generated in the gas ignited in the shell after transfer to the outside of the casing through the flange to ignite the shell,causing more serious gas explosion.Therefore,the quality of housing is very important for the safety of mine,and the quality of housing,from the housing and explosion resistance of explosion of evaluation,namely in a gas explosion occurred after the shell is damaged and the gas barrier inside the housing transfer to the outside of the shell.At present,in the manufacture of shell,flameproof enclosure wall thickness to determine no clear basis,manufacturing personnel are often based on the theoretical calculation,in order to ensure safety,according to their own experience,add a certain thickness,so the wall surface of the casing stress reserve is too large,too heavy.These electrical equipments need along with the mining working face advancing and moving,sometimes the relocation also need several reloading,so its quality is too large it is very inconvenient,in order to solve these problems,this paper selects a kind of more commonly used flameproof soft starter case study.According to the first selection circuit system of flameproof shell using the current voltage and the shell of the internal workings of the main devices of the shell,and depending on the size of the circuit system and the devices and creepage distance and other provisions of the device for a reasonable layout,according to the specific size layout to determine the flameproof enclosure.By querying the data,determine the specific volume of the shell wall burst across the surface parameters,according to the test requirements of flameproof enclosure,modeling of the shell by using Solidworks software,simulate the test process on the shell and using finite element analysis software Workbench.In the analysis of the simulation results,found that different wall shell test in the process of stress distribution are not the same,the shell of the maximum stress is less than the allowable stress,so it is necessary to optimize the shell wall thickness.This paper makes use of the zero order method provided by the Design Xplorer/VT module in Workbench to optimize the flameproof enclosure.The parametric modeling of the shell,setting range allows optimization of the parameters need to be optimized,by setting up cycles,according to the design provided by the software,the shell is optimized according to the optimization results,select the ideal data optimization.After the optimization of the shell,it is decided to use the gas explosion to test the shell.This paper uses unidirectional flow solid coupling method,establishing the mathematical model of gas explosion,the explosion process was simulated by CFD software Fluent,and the explosion process in temperature variation is derived,according to the temperature change accordingly,determine the most intense explosion reaction time,the explosion loading data of the time to the flameproof enclosure wall on solving the stress and strain.Through the analysis of the calculation results,the explosion in the shell pressure everywhere,the shell wall stress of irregularly shaped distribution,but the maximum stress is less than the allowable stress,optimization of shell is successful.After the test of explosion resistance of flameproof enclosure,it is necessary to carry out the test of explosion resistance.Based on the data obtained in the process of gas explosion,the temperature distribution in the shell is obtained,and the highest temperature of the flange is simulated.According to the simulation results,and according to the requirements of the national standard,the length of the flameproof joint surface is reasonably shortened.After the completion of the overall test and optimization of flameproof soft starter,according to the experimental conditions,the water pressure test on the analysis of test results,test process,shell has not damaged,the shell is qualified,shell thickness and quality have been reduced,provide a reference the value for the specification of flameproof shell manufacturing.