介质流速对燃气管道在线焊接背温的影响

The Effect of Flowing Rate of Media on Back Temperature of In-service Welding

运用有限元法对不同介质流速的燃气管道在线焊接的温度场进行了数值模拟,内部介质流动对在线焊接温度场的影响通过介质与管壁的换热系数来体现,考虑随温度变化的材料性能。结果表明,在线焊接时的背温随着热输入的减小而降低。内部介质流动会带走焊接时产生的热量,流速增大,背温略有下降。由于气体介质换热系数较小,介质流速对背温的影响并不明显。

Temperature fields of in-service welding under different flowing rate were simulated by FEM. The effect of internal flowing media on in-service welding was presented by coefficient of heat exchange. Temperature dependent material properties were considered. Conclusions can be made that the back temperature descends down with the decreasing of heat input. The flowing media took away the heat generated during welding. The back temperature changed little with the increasing of flowing rate. Due to small coefficient of heat transfer of gas media, the effect of flowing rate of media on back temperature was not obvious.