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为了解决城市原生污水低品位热源利用系统换热计算问题,依据污水的流变特性解析求解了定热流条件下圆管内污水的速度场和温度场,并获得了换热准则关系式.采用工程现场实验与理论计算的方法对圆管中污水的流动特性与换热能量方程进行了分析.结果表明:对于具有幂率流特征的城市污水,在广义雷诺数为4000～20000时圆管内紊流区的速度分布为v+=2.51lny++5.7;过渡区为v+=5.11lny+-3.22;层流区为v+=y+;与同条件下清水相似;而温度场较清水更复杂;对流换热准则关联式为Nuh=0.0196Reh0.91Pr0h.15.
In order to solve the problem of heat transfer calculation of low-grade heat source utilization system of urban primary sewage, the velocity field and temperature field of the sewage pipe under constant heat flow were solved according to the rheological characteristics of the wastewater, and the heat transfer criterion was obtained. Experimental and theoretical calculation methods were used to analyze the flow characteristics and heat transfer energy equation of the pipe in the pipe.The results show that for the urban sewage with power flow characteristics, when the generalized Reynolds number is 4000 ~ 20000, The velocity distribution is v + = 2.51lny ++ 5.7; the transition zone is v + = 5.11lny + -3.22; the laminar flow area is v + = y +; similar to the clear water under the same conditions; the temperature field is more complicated than the clear water; The formula is Nuh = 0.0196Reh0.91Pr0h.15.