Research on application of primary pumps to external ice melting direct supply systems for district cooling

The form and water pressure diagram of the district cooling external ice melting direct supply system are analysed, and it is found that for the secondary pump system with a upstream cooling pump and a external network circulating pump, when the height difference between the liquid level of the ice storage tank and the highest point of the system pipe network is large, the upstream cooling pump can be canceled, and the system can be changed to the form of a primary pump, and the resistance of the equipment in front of the pump can be used to increase the pressure at the most unfavorable point without changing the head of the external network circulating pump, so as to ensure the overall operation of the system without negative pressure. Compared with the secondary pump system, the primary pump system saves the initial investment of equipment and the space of the machine room, and the overall operation energy consumption of the pump is reduced. The flow regulation mode and system operation strategy of the primary pump system are analysed. Combined with an actual case, the advantages of the primary pump system are compared and explained.