Waste Heat Recovery Systems of Shampoo Drain Water from Barbershops

Two waste heat recovery systems of barbershops were presented to increase its heat utilization efficiency. One was the waste heat recovery system with water-to-water heat exchanger (WHR-HE). The other is the waste heat recovery system with both water-to-water heat exchanger and heat pump (WHR-HE-HP). The two waste heat recovery systems were analyzed by both economics and thermodynamics principles. Compared to conventional heat utilization systems of barbershops, the WHR-HE decreases annual energy consumption by 54.2%, and the WHR-HE-HP decreases annual energy consumption by 87.5%. The gain investment recovery periods of WHR-HE and WHR-HE-HP are below half one year. Compared to the WHR-HE, the WHR-HE-HP is with larger energy-saving potential, lower running cost, larger first cost and larger gain investment recovery period. The critical value of energy-saving financial subsidy is 0.778 ¥/W for the WHR-HE-HP. The WHR-HE-HP is very suited to the large and medium-sized barbershops, especially in the cold climate zone.