恒壁温条件下水平管内气固两相对流传热

Convection Heat Transfer of Gas-Solid Two Phase Flow inside Horizontal Tube under Condition of Constant Wall Temperature

对恒壁温加热条件下水平管内空气-煤粉混合物的两相对流传热进行了数值模拟和试验研究。数值模拟结果表明:壁面总传热量和壁面与固体粉末间的传热量都随着固相颗粒直径的增大而减少、随着煤粉体积率的增大而增大,而固相颗粒直径和煤粉体积率对壁面与气体间的传热量的影响不大;对流传热的Nusselt数(Nu)随着Reynold数(Rem)的增大而增大,且大Rem时的增大趋势更快;对流传热的Nu随煤粉体积率基本成线性变化。根据数值模拟提出的恒壁温条件下气固两相对流传热Nu的关联式,与试验结果具有较好的一致性。

The convection heat transfer of air-coal powder mixture flow inside a horizontal tube under the condition of constant wall temperature was simulated and investigated experimentally.The simulation results showed the total heat flow rates of wall and wall to coal powder decreased with increasing of the solid powder diameter and increased with increasing solid volume rate while there was less influence of powder diameter and volume of solid on the heat transfer flow rate from wall to air.The Nusselt number of convection heat transfer increased with increasing the Reynolds number especially for large Reynolds numbers,and linearly changed with the solid volume rate.The correlation of Nusselt number of gas-sold two phase convection heat transfer obtained from numerical simulation was well consistent with the experimental result.