Study On Fire Performance Of The Influence Of Humidity Of Typical Building Thermal Insulation Materials

With the rapid development of China's society and economy,people have higher and higher requirements on the comfort of the living environment.Almost all buildings need to use thermal insulation materials to meet the requirements of energy-saving building design.However,when building insulation materials bring energy-saving benefits,fire accidents caused by insulation also follow.Therefore,how to reasonably use thermal insulation materials,in providing a comfortable living environment at the same time,as far as possible to avoid the fire accident caused by it is particularly important.At present,in the process of green building design,designers pay more attention to the thermal insulation performance,cost and durability of thermal insulation materials,but less attention to the fire performance of thermal insulation materials.Therefore,this paper will take chengdu area as an example,focus on the study of thermal insulation material fire performance,and establish a new comprehensive evaluation index system to evaluate the comprehensive performance of thermal insulation material.In this paper,four insulation materials commonly used in chengdu area(polyurethane foam PU,extruded polystyrene foam XPS,molded polystyrene foam EPS and rubber-plastic RP)are selected as the research objects.First,the thermal conductivity of the insulation material was measured by the flat plate thermal conductivity meter.Then,the conical calorimeter was used to measure the fire performance of different thermal insulation materials with different humidity,and the order of fire risk in different working conditions was obtained.On this basis,establish pyrosim fire model,simulating the combustion heat preservation material in the actual construction situation,respectively,with different thermal insulation materials,different humidity and different fire source position of three kinds of working condition of the fire was simulated,temperature,smoke layer height,and visibility is analyzed with the changing rule of the evacuation time,get the main factors influencing the evacuation time available.Finally,considering the fire performance,thermal insulation performance,cost,sustainability and durability of thermal insulation materials comprehensively,an evaluation index system for the comprehensive performance of thermalinsulation materials is established.In the comprehensive performance evaluation of thermal insulation materials,three case were set.(Case 1: the weight of other constrained targets is determined proportionally without considering the fire performance.Case 2: five constraint objectives are considered for equalization.Case 3: five constraint targets are considered simultaneously,but different single constraint targets are stressed respectively.).Firstly,the evaluation index is normalized,and then the weight of evaluation index of each case is calculated by arithmetic average method.Finally,the performance of thermal insulation material is sorted by weighted average method,and the thermal insulation material with the best performance for different constraint targets is selected to provide reference for engineering application.Through the research in this paper,the results show that humidity has a great impact on the fire performance of insulation materials,of which the impact on RP materials is the most obvious.Chengdu area belongs to the area with high air humidity,and the impact of humidity on fire performance should be fully considered in the engineering application.In addition,the available evacuation time of fire of different insulation materials is greatly affected by the height of smoke layer.XPS has the shortest available evacuation time and the worst safety,so it is not recommended to use it in practical engineering applications.The study found that the available evacuation time was positively correlated with the length of the fire source from the room,that is,with the increase of the distance between the fire source and the room,the available evacuation time increased and the room security was higher,which was consistent with the actual situation.In the case of different constraint objectives,the comprehensive performance of insulation materials is not the same,RP performance is the best when the insulation performance and fire performance are stressed respectively.When sustainability and cost were stressed,the comprehensive performance of insulation materials was consistent,EPS performance was the best,PU performance was the worst.When durability is emphasized,PU performance is the best and EPS the worst.Therefore,in practical engineering applications,insulation materials should be selected according to the actual situation to ensure the optimal comprehensive performance.