Circulating water from power plant contains a large amount of waste heat.Using water source heat pumps to recycle the waste heat no only can enhance the thermal efficiency of power plant

but also can reduce the pollution by decreasing coal consumption rate.Taking a 600 MW unit as the example

experiments were carried out on recycling the circulating water waste heat by water source heat pumps.The results show that

during a heating period

the recyclable waste heat is 27 223.13MW·h

and the amount of coal savings and economic benefits of recycling waste heat are 3 343.79 tand 1.839 million yuan respectively.In addition

the unit economics can be evaluated by calculating the annual cost and payback period.The annual cost is 22 090 million yuan/year and the payback period is 3.96 years.