高温温差发电装置集热器结构数值仿真研究

Numerical Simulation of Heat Collector Structure for High Temperature Thermoelectric Generator

设计了一种针对高温烟气的圆筒式温差发电装置,在装置中设置分流桶增强烟气侧的换热效果。利用Ansys Fluent软件对装置的温度场、速度场及排气压降进行仿真模拟,分析了不同分流桶的桶直径、端盖孔直径和分流孔直径对热电模块冷热端温度分布的影响。仿真结果表明:温差发电系统集热器通道中设置分流桶可以实现高效温差发电,分流桶端盖未开孔时装置的换热效果优于端盖开孔结构;适当减小分流孔直径或增大分流桶直径会提升热电模块的冷热端温差,分流孔直径为2 mm时的换热效果最优,分流桶直径过大会使热电模块温度分布及温差的均匀性降低;系统烟气压降会随着分流孔直径的增大或分流桶直径的减小而降低。

A cylindrical thermoelectric generator(TEG)was designed for high temperature flue gas,and a shunt bucket was set in the device to enhance the heat transfer effect of the flue gas side.The tempera-ture field,velocity field and exhaust pressure drop of the TEG were simulated by using Ansys Fluent soft-ware.The influence of the diameters for different shunt buckets,end cap holes and shunt holes on the temperature distribution at the cold and hot ends of thermoelectric modules(TEM)was analyzed.The re-sult shows that high effective thermoelectric generation can be achieved by setting a shunt bucket in the high-temperature flue gas channel;the heat transfer effect of the device is better than that of the open structure when the end cover of the shunt bucket is not open;the temeperature difference between the hot and cold ends of the thermoelectric module can be increased by appropriately increasing the diameter of the shunt bucket or decreasing the diameter of the shunt hole appropriately.The heat exchange effect is the best when the diameter of the shunt hole is 2 mm.The temperature distribution and temperature difference uniformity of the thermoelectric module will be reduced when the diameter of the shunt bucket is larger;the pressure drop of flue gas will be decreased with the increasing diameter of the shunt hole or the decreasing diameter of the shunt bucket.