基于线热源模型的喷射火焰热辐射计算方法

摘要

In order to improve the calculation precision of heat radiation intensity of the point heat source model in a fire scenario,and to estimate the heat radiation intensity rapidly,the linear heat source model is proposed.The jet flame is assumed to be a linear heat source where the heat load is distributed on the center of flame centerline uniformly,the shape of the central line is also under consideration.Through the analysis of the two cases,the results show that the linear heat source model improved the accuracy of the prediction results of the thermal radiation than the point source model,and the linear heat source model is simpler and easier than the calculation process of the solid model,which can meet the requirement of rapid estimation.Although the influence of the flame length is considered in the calculation process of the linear heat source model,the possible impact of its width and the unevenness of the thermal load distribution along the length of the flame was not take into account,which may cause errors between the calculated results and the real results,these issues need to be further studied.%为提高喷射火灾场景中对热辐射强度的预测结果的准确度,并且能够对热辐射强度进行快速估算,将喷射火焰视为热载荷密度均匀分布于火焰中心线上的一条线热源,并考虑火焰中心线的形状,提出基于线热源模型的火灾热辐射计算方法.通过对两个案例进行分析,结果表明:线热源模型比点源模型提高了火灾热辐射预测结果的精度,比固体模型的计算过程更为简单便捷,满足工程快速估算的需求.火焰线热源模型考虑了火焰长度方向的影响,但未考虑其宽度方向可能造成的影响和火焰沿长度方向上热载荷分布的不均匀性,这可能引起计算结果与真实结果之间的误差,还有待进一步的研究.