The Construction And Simulation Test Research Of Flame Resistant Cable Simulation Model

With the rapid development of industrial technology,people have higher and higher demands for wires and cables.The fire caused by wires and cables account for more than 60% of the total number of electrical fires.The high proportion of fires has caused widespread concern about the development of flame retardant cables and their combustion performance testing.How to effectively improve the flame retardant performance of flame retardant cable and realize the rapid detection of flame retardant cable combustion performance is an urgent problem to be solved.In this paper,according to the old standard and the new standard of cable combustion test under the condition of flame,the typical flame retardant cable and combustion chamber simulation models are constructed by fire dynamics simulation software,and the simulation results are compared with the full-size experimental results.The difficulty of the same type of cable to pass the cable combustion test under two different standards is compared and analyzed.The ignition temperature,heat release rate per unit area,specific heat capacity,bulk density,thermal conductivity and other parameters that affect the cable combustion performance are analyzed.The influence of initial internal temperature of sheath and cable spacing size on cable combustion performance is discussed.The analysis results show that the old standard model agrees well in the carbonization height and the maximum temperature of the cable combustion box.The maximum relative error of the new standard model in terms of peak heat release rate is 9.85%,and the maximum relative error in terms of carbonization height is 13.79%,which is within an acceptable range.The comparison of simulation and experimental results verified the accuracy of the model and the feasibility of the method.Compared with the old standard,the new standard is more difficult to pass the combustion performance test in terms of box temperature and carbonization height,but it is easier to pass the test in terms of smoke density.Among the properties of the sheath material,the ignition temperature,heat release rate per unit area,and specific heat capacity have a greater impact on the combustion performance of the bundled cable.In the design and production of the sheath material,the ignition temperature should be considered first.On the premise of the ignition temperature,consider adjusting the heat release rate and specific heat capacity per unit area of the material to reduce the burning performance of the cable.The initial internal temperature has little effect on the overall trend of cable combustion and fire development,and the combustion performance of bundled cables does not change linearly with the size of the pitch.