R290热泵供热换热器的节能性能研究

Investigation on Energy-Saving of R290 Heat Pump Heat Exchanger for Heat-Providing

通过建立R290热泵供热换热器模型,对R290供热换热器的总传热系数进行计算,得出增大R290的质量流速,减小换热管的直径,降低冷凝饱和温度,可增加总传热系数,减少供热换热器尺寸,节约金属材料。通过对R290冷凝流动过程的压降计算,得到随着换热管内径、换热管长、R290质量流量和冷凝温度的变化,沿程阻力压降的变化最大,而局部阻力压力降和加速度阻力压降的变化较小。应从系统运行性能和加工成本等方面综合考虑,优化选择合适的管径、管长和R290质量流量,以节约能源,保护环境。

By setting up the model of R290 heat pump heat exchanger for heat-providing, the total heat transfer coefficient of R290 heat exchanger for heat-providing is calculated, it can be concluded that Increasing the mass flow speed of R290, decreasing the diameter of heat transfer tube, reducing the saturation temperature of condensation can enhance the total heat transfer coefficient of R290 heat exchanger for heat-providing , so as to reduce size of R290 heat exchanger for heat-providing, save the material of metal. Based on the pressure fall computation results of R290 condensation flow process, the change of the diameter of heat transfer tube, the length of heat transfer tube, the mass flow speed of R290 and condensation temperature affects the pressure fall of flow process resistance obviously, however the change above have very small effect on the local resistance pressure fall and acceleration pressure fall. So the system performance and cost must be considered synthetically, selecting the diameter of heat transfer tube, the length of heat transfer tube and the mass flow speed of R290 suitably, in order to save energy and protect environment.