| Centralized heating has been developed in China for many years,but the problem is still very significant that heat load allocation between the heat users of each branch on the secondary pipe network of the secondary heat exchange station is unbalanced.When the heat demand of a branch is increased or decreased,it is necessary to adjust the flow of the branch,which is bound to cause the whole secondary pipe network flow pressure redistribution.If the flow of secondary pipe network is not allocated as a whole,there will be uneven cold and heat at each hot client end,which will seriously affect the comfort level of heating and cause heat waste.Therefore,it is very important to study the reasonable distribution of secondary pipe network flow in heat exchange station for heat supply balance and green heating.Through the analysis of the thermal and hydraulic conditions of the central heating system,the optimal flow regulation method is obtained,that is,the supply and return water temperature and flow rate of the indoor temperature are satisfied at a certain outdoor temperature.When the heating system is initially adjusted,the flow of the heat user of a branch changes due to the change in heat demand.In order to meet the heating demand of the heat user without affecting the heating demand of other heat users,the heat exchange station is constructed.The power consumption model of the secondary pipe network circulating pump motor,the main constraint condition of the model is the opening degree of each branch electric control valve and the hydraulic balance state of each branch.Using the powerful optimization ability of genetic algorithm,by introducing the penalty function,the constraint problem is transformed into an unconstrained problem,and the heating balance of all the branch heat users on the heating system is used as the ultimate goal for optimal control.The simulation results show that the operating power consumption of the circulating pump motor is minimized when the heating balance of all the branch heat users is satisfied,and the opening setting of each electric regulating valve is obtained.The method effectively improves the heating needs of the thermal users and saves about 7.6% of the thermal load. |
