Energy saving potential analysis on water pump frequency conversion technology in indirect sewage source heat pump system

Sewage source heat pump is widely promoted and used as a green heating technology. In order to study the energy saving potential of indirect sewage source heat pump system, this paper builds a simulation model of indirect sewage source heat pump system based on transient simulation software TRNSYS. The model is verified by measured data. Simulate and analyze the energy consumption of the system running with frequency conversion on one side of the source side water pump, frequency conversion on both sides of intermediate water pump and load side water pump, frequency conversion on all three sides. And optimize the frequency conversion range of the water pump through Partical Swarm Optimization (PSO). Compare and analyze the energy consumption of water pump, the energy consumption of the unit, the total energy consumption of the system, coefficient of performance of the unit (COPunit) and coefficient of performance of the system(COP
sys
). Research shows that the optimal operating frequency ranges of the source side water pump, intermediate water pump, and load side water pump are respectively 25Hz ~ 50Hz, 32Hz ~ 50Hz, 33Hz ~ 50Hz. When the pumps are in variable frequency and run in their respective optimal operating frequency ranges, the operating energy consumption of the system is the lowest. The energy saving rate of the system is 19.88%, COPunit is 5.00, and COP
sys
is 4.17. The research results provide a reference for the optimization operation research of sewage source heat pump system.