Strong self-flushing technique for heat exchanger of sewage source heat pump system

To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.

To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system (USSHPS), this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economical and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than $5 and when one flushing pump alternately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.