Research On Heat Distribution Strategy Of District Heating Primary Network

District heating is the main way of urban heating in China,the energy consumed by the system can account for more than half of the total energy consumption of the building It is found that there are problems in the development of the central heating system,such as not intelligent and low control precision.Based on the operation data of "K district heating System" in central China,this paper studies the heat distribution of primary district heating network.Simulation models are established and a heat distribution strategy based on load prediction value is proposed.First of all,a survey was conducted on "K district heating system",and more than2800 sets of data were obtained after data collection in the heating season for 4 months.According to the requirements of modeling,the data are preprocessed,and the heat model of the district heating network and the heat load prediction model of the heat exchange station are established by using the gate recurrent unit algorithm(GRU).And the reliability of the established models is verified.Then,according to the law of conservation of mass and energy,the mathematical models of the main parts of the primary heating network of the district heating system are established,and the corresponding simulation modules are built in Simulink based on the mathematical models,and the reliability of the simulation model is verified by the measured data.Aiming at the problem of unreasonable heat distribution,the heat distribution was studied based on the heat model of primary network combined with the heat load prediction model.Finally,the heat distribution strategy of primary side flow optimization of heat exchange station was proposed based on the demand heating.According to the idea of on-demand heating,the error between the predicted load value and the heat output value of the primary network model was taken as the objective function,and the chaotic particle swarm optimization(CPSO)algorithm was used to optimize the primary side flow sequence of each heat exchange station,and the optimal primary side flow is used to control the heat distribution of the secondary network.In order to verify the change of the operation effect of the secondary network after the optimization of the primary side flow of each heat exchange station.The primary network model is used to simulate the optimized heat supply and compare it with the ideal heat of each heat exchange station.Through the established Simulink simulation model,the optimized input variables were used to simulate the water supply temperature of the secondary side of the heat exchange station.Then,the heat supply of each heat exchange station in the primary network and the operation of the secondary side are analyzed.The results verify the effectiveness of the distribution strategy.The actual case application and simulation results show that the heat distribution scheme proposed in this paper can effectively distribute the heat of each heat exchange station according to the heat demand.In addition,the district heating system in this case belongs to the typical district heating system in central China.Based on this district heating system,the primary side heat distribution strategy of heat exchange station is universal and can be applied to all types of central heating systems and other pipe network systems with similar structure.