| With the rapid improvement of China’s national economy,people’s living standards and living environment have further improved,and central heating has achieved rapid development.At the same time,the energy consumption of the central heating system is also increasing.In the context of vigorously promoting energy conservation and emission reduction in China,how to use scientific heating regulation to improve the energy efficiency and reduce energy consumption of centralized heating pipe network is an important issue at present.In this paper,the secondary pipe network of central heating system is taken as the research object,the initial adjustment simulation study of the heating pipe network is carried out.And the simulation study is performed using different operational adjustment methods for the different stages of the whole heating period.The main research contents of the thesis are as follows:(1)Initial adjustment of the heating pipe network.Based on the network graph theory,the basic matrix and the independent loop matrix are generated by the peak array describing the topology of the pipe network.and the calculation model for the hydraulic condition of the heating pipe network is established,and the simulation analysis method and the improved square root method is adopted.And use Java software to write the solver and perform the simulation calculation,and obtain the transition flow of each branch of the user to be regulated and perform initial adjustment of the heating pipe network.Among them,the pump working curve is fitted by the least square method and the heating pipe network characteristic curve are used to determine the pump working point.And the heating pipe network characteristic curve and the pump working point before and after the initial adjustment are compared and analyzed.(2)Operation adjustment of the heating pipe network.The entire heating period is segmented according to the change of the heat load.A adjustment model of maintain the small-flow operation during the initial cold and end cold period and the quality adjustment of the flow is changed in different stages during the severe cold period is established and simulated by Java software to obtain the adjustment curve of the supply and return water temperature and circulation flow at each stage.The calculation formula of the power consumption of the variable frequency water pump in each stage is deduced,and the power consumption of the variable frequency water pump in each stage is calculated and compared with the quality adjustment of the water pump running at a large flow rate,and the power saving analysis is carried out.Using the Java calculation program to simulate the initial adjustment of the secondary pipe network of a university in Shijiazhuang City and adjust the actual pipe network according to the established initial adjustment scheme.Comparing the flow in each user branch to be adjusted after the simulated adjustment with the actual pipe network adjustment,and the maximum flow error is 9.50%,which verifies the rationality of this simulation adjustment scheme and program.Applying the adjustment model of each stage proposed in this paper,the secondary pipe network is adjusted in the entire heating period from November 15,2017 to March 15,2018.The power consumption analysis is carried out,and the power consumption can reduce 20 627 kW·h in the entire heating period,which greatly reduces the power consumption of the pump. |
