消防水幕衰减火灾辐射热的理论研究

Theoretical Study on Fire Radiation Attenuation with Water Curtains

从消防水幕系统中水滴粒子与火焰辐射热的散射和吸收作用出发,建立水滴与火焰辐射的数学模型;通过计算机求解获得了不同条件下水幕的隔热效率;并定量计算了水滴的粒径、荷载强度和水幕厚度对水幕透射率的影响;同时,计算并分析了目标体瞬态温度和平衡温度的变化规律。为了验证理论模型的可靠性,进行了全尺寸的火灾实体实验,理论预测和实验的结果比较接近。笔者的研究结果对于优化消防水幕设计和改进系统的性能在理论和实践上都具有一定的指导意义。

A simple calculation model was proposed to determine the attenuation of the fire radiation by means of the scattering and the absorption traits of the water droplets produced by water curtain. Thermal shielding efficiency of the water curtain in different conditions was achieved by iteration method, and the influences of droplet ＂s size, droplet＇s loading intensity and the curtain thickness on transmittance were quantitatively analyzed. Moreover, the transient temperature and the balance temperature of the target object were computed and their changing laws were discussed. Finally, full-scaled fire tests were conducted in order to validate the reliability of the model. The results show that the relative errors respectively obtained by the calculation model and the tests are close. This study is favorable to theoretically and practically direct the optimum design of water curtain and the improvement of its performance.