Dynamic simulation for a mixing water district heating system

Develops the nonlinear dynamic model for a mixing water district heating system. Analyses dynamic characteristics of the system and the influences of pipe heat loss, ratio of makeup water, ratio of mixing water, solar radiation and internal heat gains on indoor air temperature. Simulates the dynamic responses of indoor air temperature under four control strategies. As a result, the indoor air temperature could be satisfied by regulating return water temperature, and energy savings of fuel could be obtained up to 97%.