Application of Hydroturbine-pump to recycling water-source heat pump system by using gravitational potential energy

In mountain-rich topographical cities such as Chongqing in China, the energy consumption of intake-water normally exceeds the standards due to the great elevation difference between the drainage pool and river level, which is approximately 30 meters. Meanwhile, the change of river water level also causes trouble in pump operation, which persist a fluctuation of more than 11.24 meters annually. This paper propose a concept and systematic mode of energy recycling water-source heat pump system, which provides the energy for cooling water intake by water turbine pump and frequency conversion pump in series-parallel connection. By fitting the performance curve of turbine pumps with that of the frequency conversion pumps, this paper present an optimized pump frequency control method by adjusting the load range, which provide a good reference for designing of energy recovered water-source heat pump. With control methods of water supply system, the limitation for the applications of river water-source heat pump system in large elevation difference will be overcome. By showing the efficiency of this new energy saving system, the importance of determining the characteristic parameters of water-source heat pump in system design, operation and management is emphasized.