Experimental study on low temperature return water with combination of electric heat pump and heat storage system

The contradiction between the limited transmission capacity of the existing urban central heating network and the increase of heating demand is increasingly prominent. Presents a heat exchange station system with electric heat pump and heat storage device that can reduce the return water temperature of the primary network to 20 ℃, and the delivery capacity of the primary network at 120 ℃/20 ℃ at the same flow rate is 66.7% higher than that of the conventional central heating system at 120 ℃/60 ℃. Moreover, the electric heat pump in the thermal power station only operates during the off load period at night, which significantly reduces the operating cost compared with the single electric heat pump mode. The lower return water temperature of the primary network is conducive to the recovery of low-grade heat, such as boiler flue gas waste heat or cogeneration exhaust steam waste heat in the central heating heat source, so as to significantly reduce the energy consumption of the central heating system.