火球热辐射改进计算模型

A Modified Method of Calculating Thermal Radiation of Fire Ball

为对火球热辐射影响范围进行合理的计算和危险后果进行合理评价,借鉴点源模型和计算流体力学CFD思想,建立了火球热辐射改进计算模型,并与点源模型进行了对比。结果表明:改进模型比传统的点源模型计算结果偏大,特别是距离火球较近处。随着半径的增加,2种模型的计算结果趋于统一。当测量点的半径大于火球半径的2倍时,可以使用点源模型进行热辐射量的计算,满足工程精度要求;在近火球位置,点源模型精度较差,须用改进模型进行计算。建立的改进计算模型可以实现火球热辐射的快速计算,是有效、可行的。

For reasonably calculate the radiation range of fire ball and evaluate its dangerous consequence,a modified thermal radiation calculation model for fire ball was established based on point source model and CFD theory.And the result was compared with that obtained by point source model.It shows that the result gotten by the modified model is bigger than that by the traditional point source model,especially under the condition near fire ball.With the increase of the radius,the results gotten by the two models tend to unity.When the calculation points are beyond the distance of twice radius from the fire ball,the point source model can be used,and the accuracy meets the engineering requirement.In the positions near fire ball,the accuracy of point source model is bad and the modified model should be adopted.The fast radiation calculation for fire ball can be realized with the modified radiation calculation model.It is concluded that the modified radiation calculation model is effective and practical.