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采用数值模拟方法研究高温高压下气化炉中膜式螺旋管煤气冷却器的对流换热和流动特性,分析径向节距、轴向节距和管圈曲率对换热和流动特性的影响。模拟结果与试验结果吻合较好。研究发现:在相同的入口速度下,膜式螺旋管换热器的表面换热系数与轴向节距和径向节距有关;换热器环形通道内的轴向速度波动有利于强化传热;膜式螺旋管的局部壁面换热系数与管圈曲率无关;螺旋管圈的膜片面积比对于换热器的平均换热系数有显著影响。另外,该文还获得了换热器的阻力特性与径向节距和管圈曲率的关系。
The numerical simulation method was used to study the convective heat transfer and flow characteristics of gas-liquid coolers in gasifier under high temperature and high pressure. The effects of radial pitch, axial pitch and tube curvature on heat transfer and flow characteristics were analyzed. The simulation results are in good agreement with the experimental results. The results show that at the same inlet velocity, the surface heat transfer coefficient of the membrane spiral heat exchanger is related to the axial pitch and radial pitch. The axial velocity fluctuation in the annular passage of the heat exchanger is conducive to enhanced heat transfer ; The local wall heat transfer coefficient of the membrane spiral tube has nothing to do with the curvature of the coil; the diaphragm area ratio of the spiral coil has a significant effect on the average heat transfer coefficient of the heat exchanger. In addition, the article also obtains the relationship between the resistance characteristics of the heat exchanger and the radial pitch and the curvature of the pipe.