Research on Waste Heat Recovery in Drain Water of Barbershop

Drain water at 35°C was directly discharged into sewer in most of barbershop with Electric water heater. Heat utilization efficiency is lower, and energy grade match between input and output is not appropriate in most of barbershops. Two waste heat recovery systems were presented according to the heat utilization characteristics of barbershops and principle of cascade utilization of energy. One was the waste heat recovery system by water-to-water heat exchanger (WHR-HE), and the other is the waste heat recovery system by water-to-water heat exchanger and high-temperature heat pump (WHR-CHEHP). The two heat recovery systems were analyzed by the first and second Laws of thermodynamic. The analyzed results show that the energy consumption can be reduced about 75% for HR-HE, and about 98% for WHR-CHEHP. Both WHR-HE and WHR-CHEHP are with better energy-saving effect and economic benefits.