Control strategies and energy consumption of an indirect district heating system

Develops a set of dynamic models for an indirect district heating system, including the models of pumps and adjusting valves, in terms of the mass and energy principles of conservation. Simulates and analyses the influences of outdoor temperature, solar radiation and indoor heat gains on the system water temperature and indoor temperature. Simulates the system operational states and the energy consumption in five different control strategies, based on oneweek actual meteorological parameters as outer interference. The results show that the most stable indoor temperature could be achieved when implementing the joint control strategy of adjusting the fuel consumption of the boiler to control the water supply temperature, the primary piping network and the radiator circulating water flow rates. The energy consumption is the lowest when implementing the joint control strategy of adjusting the fuel consumption of the boiler to control the supply water temperature and the primary piping network flow rate to control the of indoor temperature. The power consumption would be greatly reduced if variable frequency circulating pump is applied to the primary piping network.