Study And Establishment Of Test Device Of External Thermal Insulation Materials Of Smoldering Combustion

Fire usually leads to massive loss on the human life and property,smoldering is a main factor that causes fire.Currently few researches on smoldering for external thermal insulation material are found.Some researchers focus on either mono material or single object.It is also not easy to find some studies on experimental equipment and method on smoldering for external thermal insulation material and experimental studies on smoldering for external thermal insulation material.In this paper a set of experimental equipment on smoldering was built and the tests were carried out on seven selected materials including rock wool,polyurethane,Luobaoban,extruded polystyrene(XPS),expanded polystyrene(EPS),thermosetting modified polystyrene and phenolic foam board and discussed the smoldering characteristics on different materials.Works and conclusions were shown below:A electrical dry oven was designed based on power computation,components-select and design on dry oven structure and a software system for sampling data was designed,finally the whole experimental equipment on smoldering characteristic was built,experimental procedure was made and a series of methods for smoldering test were created.The results showed that experimental equipment on smoldering characteristic met the demands of nation standard GB/T 29416-2012 Test method for fire-resistant performance of external wall insulation systems applied to building facade.Smoldering characteristic on rock wool was studied.The experimental observations showed that the temperature inside rock wool started rising from 200℃ at 5.5 h from the start of the test and at the same time smoldering happened to rock wool.And heat release ended with inside temperature increasing up to 330℃ at 11 h.Rock wool remained its original shape without volume shrinkage and break.Smoldering characteristic on polystyrene foam and Luobaoban was studied.The experimental observations showed that the temperature inside polystyrene foam started rising from 380℃ at 14 h from the start of the test and smoldering happened to polystyrene foam,and the highest temperature increased up to 600℃,finally heat release ended at 20 h.During the test,the shape changed a little and the volume of polystyrene foam decrease a little but color became black.And Luobaoban had the similar smoldering characteristic like polystyrene foam.Smoldering characteristics on extruded polystyrene and expanded polystyrene were studied.The results showed that smoldering didn’t happen to extruded polystyrene and expanded polystyrene.During the test,extruded polystyrene and expanded polystyrene disappeared.Smoldering characteristic on thermosetting modified polystyrene was also studied.The experimental results showed that the temperature inside thermosetting modified polystyrene started rising from 200℃ at 6 h from the start of the test and at the same time smoldering happened to polystyrene foam.The first peak temperature reached 525℃ at 9 h,and the second peak temperature reached 575℃ at 12 h,and then the temperature started decreasing to 400℃ at 13 h with heat release ended.During the test thermosetting modified polystyrene kept its original shape but its color became black and volume shrank.Its structure became fragile and strength lowered.Finally,smoldering characteristic on phenolic foam board was also studied.The experimental results showed that the temperature inside phenolic foam started rising from 175℃ at 5 h from the start of the test and at the same time smoldering happened to phenolic foam.The first peak temperature reached 460℃ at 8 h,and the second peak temperature reached 490℃ at 11 h,and then the temperature started decreasing up to 400℃ at 12 h with heat release ended.At the end of test,phenolic foam was broken.