Compared with ordinary single-source heating systems

multi-source district heating systems have many advantages such as low operating cost

low primary energy consumption and high reliability in heat supply. Against the optimization problem of heat source load distribution and scheduling in the operation process of multi-heat source central heating system

a scheduling optimization model for a multi-sources district heating system is developed to predict and determine the operation state and the thermal load of each source with good economic and environmental performance at different ambient temperatures. Both the operating cost and the integrated pollutant emissions have been taken as optimization goals and the heat demand requirements for the customers are also considered in the model. The dimensionality reduction or relaxation method for equality constraints is introduced to make the solution of the optimization model easy. Then

the multi-objective optimization model is solved by the NSGA-II method and the TOPSIS method. At last

the scheduling optimization model is applied in a case study of a multi-sources district heating system with three heat sources including a gas-fired thermal power plant(with design heat load of 147 MW)

a gas-fired boiler(with design heat load of 80 MW) and a second-class absorption heat pump system(with design heat load of 41.2 MW)

and the heat source optimization scheme and heating regulation method are given. In the optimal scheduling scheme

the absorption heat pump system is operated at the full load mode to optimize both the operating cost and integrated pollutant emissions of the district heating system. In the proposed regulation scheme

the gas-fired thermal power plant is operated under part-load conditions to reduce the operating cost. Additionally

the heat load distribution for all heat sources are done by the water flow distribution in the cold period.