Study On Structure Design And Anti-explosion And Thermal Insulation Performance Of Movable Refuge Chamber For Mine

Gas explosion is considered as a main factor to cause serious mine accidents,which has the huge power of instantaneous destruction.Meanwhile,it is easy to cause another explosion and serious casualties.The use of emergency actions system can increase opportunities for survival of the jammed people underground coal mine,and improve the rescue efficiency.Movable refuge chamber for mine has such characters as strong mobility,short start-up time and simple installation.Therefore it becomes an important equipment of underground hedge.This dissertation studies on the structure design of the movable refuge chamber at first.Then its dynamic response under explosion shock loading is investigated.In addition,the coupling effects between the refuge chamber and the explosion and high temperature shock are analyzed.The obtained results can provide scientific basis for structure improvement and safe use of the movable refuge chamber.(1)The structure design was theoretically analyzed according to the ―General Technical Conditions of Mobile Refuge Chamber for Mine‖.Then the structure form and size were designed combined with the specific characteristics of underground coal mine.Meanwhile the geometry model of refuge chamber was conceptually designed using the three-dimensional modeling software UG NX 8.0.(2)The fluid-solid coupling simulation platform was established using the module ―Explicit dynamics‖ and the dynamic analysis software ―AUTODYN‖(both are in the ANSYS Workbench).After that,the propagation process of gas explosion shock wave in the roadway was simulated through TNT equivalent method,which replaced gas with TNT.Then dynamic response of the refuge chamber under the over-pressure loading was studied.In the roadway explosion simulation,three different amounts of TNT(78.24 kg,68.377 kg and 61.36 kg)were contrasted and finally the 68.377 kg TNT was chosen as the load condition when it referred to the explosion shock wave overpressure curves of the refuge chamber’s various surfaces.(3)The real blast load curve obtained from the above fluid-solid coupling simulation was imposed on the surfaces of the refuge chamber,and the strain and deformation under explosion load were analyzed.According to the yield criterion,time history curve and deformation distribution under equivalent stress and equivalent plastic strain were obtained,and the maximum stress and deformation position were found.According to decision criterion,the safety and reliability of the refuge chamber under explosion load,which was designed by this dissertation,was checked by judging whether the chamber structure was destructed or not.The results indicated that the whole refuge chamber’s maximum deformation was up to the range of the safety criterion(less than 2% for deflection or 20 mm for deformation),which was 11.145 mm.The maximum stresses of the front and back door systems,flange and outer skin were less than the yield strength of the selected material.By the way,the overall safety of the refuge chamber would not be influenced although the stiffener could cause some local yield and stress concentration.(4)According to the ―General Technical Conditions of Mobile Refuge Chamber for Mine‖,the thermal protection performance of the movable refuge chamber under continuous and instantaneous high temperature was simulated and analyzed.Through the coupling of Thermal Transient module and Static Structural module in the finite element software ANSYS Workbench,temperature field distribution,the temperature change curve,thermal stress and thermal deformation data were obtained.The results showed that,the movable refuge chamber’s inner maximum equivalent thermal stress was 243.36 MPa under continuous high temperature heat load,and was 262.14 MPa under instantaneous high temperature heat load,both of which were lower than the yield strength(345MPa)of the material.The refuge chamber’s maximum whole deformation was 0.556 mm under continuous high temperature,and was 0.6496 mm under instantaneous high temperature,both of which were relatively small and therefore could not cause too large deformation of the refuge chamber or destructions.