Fine Modeling in Thermal System of Integrated Energy System

The integrated energy system (IES) is a system of coordinated planning and unified dispatching of various energy sources. It uses the coupling of electricity, heat and gas to improve the efficiency of system operation, so as to improve the energy efficiency. Up to now, due to the diversity of thermal equipment, the structure of thermal system has become very complex, but its essence is nothing more than the calculation of thermodynamic properties of various substances. This paper focuses on the thermodynamic calculation of thermal system and summarizes the basic principles of engineering thermodynamics and general empirical formulas in detail. Based on the idea of fine modeling, a general calculation model is built for the density, saturation temperature, saturation pressure, enthalpy, entropy and other state parameters of gas and liquid under ideal and actual conditions based on the MATLAB/Simulink platform. It provides a model foundation for subsequent modular modeling and IES node and network research. It has strong scalability and can adapt to the needs of continuously developing and more complex heat networks. Finally, the feasibility of the model is verified by simulation analysis.