为研究层化环境对内部火灾烟气扩散的影响,以线羽流为研究对象,在正常环境下线羽流流动特性研究的基础上,通过理论分析对恒温度梯度环境中线羽流的流动特性进行了分析研究,得到线羽流的扩散半径、轴心速度、轴心密度差随高度的变化规律,线羽流所能达到的最大高度,烟气浮力发生变化的临界高度等. In order to study the influence of stratified environment on the smoke diffusion in internal fires, the plume flow is taken as the research object. Based on the research on the plume flow characteristics in normal environment, the flow characteristics of plume plume in a constant temperature gradient environment are analyzed theoretically. The analysis of the plume plume flow radius, axial velocity, axis density difference with the height of the law, the line plume can reach the maximum height, the flue gas buoyancy changes the critical height.