Research on hydraulic calculation of heating pipe network based on graph theory

The centralized heating pipe network is a multi-connected network with a relatively complex topological structure. Graph theory can simplify the complex pipe network and express it in the form of graphics and data, using the topological structure of nodes and pipe segments to reflect the heating pipe network model. By establishing matrix equations, the pressure at pipe network nodes and the flow rate of pipe segments can be calculated and analysed. Based on the actual parameters of the pipe network, this paper establishes a mathematical model of the heating pipe network according to the basic principles of graph theory and Kirchhoff’s voltage-current law. According to the known pipe network structure, fluid parameters and operation conditions, the pressure and flow distribution at each node in the heating pipe network are calculated. Taking the heating pipe network in Taiyuan as an example, the mathematical model and the solution method are verified, and the relative error of the calculation results is less than 8%. The research results can provide a basis for the operation state analysis, optimal design, scheduling control and fault diagnosis of the heating pipe network.