城市污水的流动特性理论研究

Theoretical research on flow characteristic of urban sewage

摘要:

为了能使城市污水在污水源热泵方向进一步推广应用,以原生污水源热泵系统中的流动工质——城市污水为研究对象,采用理论推导与实验相结合的方法对城市污水在圆管中层流和紊流的流动特性进行分析与研究.结果表明:城市污水在流变性上体现为剪切稀化流体特性,可以通过临界广义雷诺数判别流态.在此基础上,通过理论推导得到了层流和紊流状态下的压降计算公式,并且通过阻力特性实验进行了验证.研究结果对原生污水源热泵系统中水泵的选择有一定的指导意义.

Abstract:

In order to extend the utilization of urban sewage in sewage heat pump system,based on the urban sewage which is the flow working fluid in untreated sewage heat pump system,characteristics of laminar flow and turbulent flow were studied in theoretical derivation and experimental analysis.The results show that the urban sewage has the shear-thinning characteristic in rheology,so the generalized Reynolds number can be used to determine the flow pattern.The pressure loss equations under laminar and turbulent flow conditions were deduced theoretically and verified by experiment.The research results are favourable for pump choose of untreated sewage heat pump system.