System Design Of Explosion Test Device For Flameproof Electrical Equipment And Experimental Research

The most basic and reliable explosion-proof type of explosion-proof electrical apparatus is flameproof type,and the core and key type test of explosion-proof electrical apparatus is explosion test.The performance and technical parameters of the explosion test device are the basis for judging whether the explosion-proof performance of the equipment can meet the requirements of standards.Therefore,the quality and safety of explosion-proof electrical products are determined by strengthening the research of explosion experiments and improving and optimizing the design of explosion test devices.A three-dimensional dynamic flow distribution device was designed on the basis of the study on the principle of mass flowmeter,the inner and outer ring PID control method of mass flow and the principle of a mass flow controller shared by serval kinds of gases.What's more,the design of the tank control and pressure distribution system was optimized.At last,a comprehensive explosion test device was designed.The device combines dynamic flow distribution with partial pressure distribution,and can accurately,efficiently and systematically complete the pressure test and internal ignition non-propagating explosion test.All the tests specified in the comparison scheme have been completed using the standard device designed for pressure comparison test.Through the analysis of the experimental results,it was proved that the parameters of the test device meet the design requirements,and could fully satisfy the accuracy requirements of the standard for test device.The functions of filling air into the test tank and flammable mixture gases into the test prototype to complete 1.5 times over-pressure test were realized,which greatly improved the efficiency and economy of the test.The selection type of equipment and hardware,the design of circuit and software was completed.Aiming at the low output pressure of acetylene cylinder,which couldn't satisfy the pressure difference required by the flow controller for normal operation,a two-way synchronous regulated bypass was added.The two-way synchronous regulated bypass was controlled by a manual open-loop PID,and the binary flow distribution function of acetylene and air was realized.The explosion test of Class II C equipment can be completed under the pressure of less than 0.15 MPa.The main factors affecting the low explosion pressure were analyzed,it was verified that the failure of the solenoid valve had a greater impact on the explosion pressure by replacing the solenoid valve with the manual ball valve.Compared the air with an average humidity of 73% with the dry air,the average explosion pressure of ethylene and hydrogen increased by 2.15% and 1.5% respectively.The influence of humidity on the explosion pressure of ethylene was higher than that of hydrogen.It was analyzed and verified that the temperature of the test prototype after explosion had a significant influence on the explosion pressure.After the test,the standard deviation of the explosion pressure is obviously reduced and the repeatability is improved.After the test,The standard deviation of the explosion pressure was obviously reduced and the repeatability was improved by cooling the temperature of the test prototype to ambient temperature after the experiment.The other factors affecting the low explosion pressure were listed,and the corresponding measures and improvement suggestions were analyzed.The improvement measures and research directions for the improvement of the test device were put forward.