Energy Flow Calculation of Electricity-Heat Integrated Energy System Considering Local Head Loss

Abstract

Energy flow calculation of IES (integrated energy system) aims to calculate the node voltage and pressure, branch current and mass flow rate, working medium temperature and other state parameters according to known information. In the existing researches on energy flow calculation, only the friction head loss is considered and the influence of local head loss is not involved because of the complexity of the pipe structure. The local head loss occurring at abrupt flow boundary changes, such as variable section pipes, pipe inlet and outlet, and pipe connections is inevitable. The output of units and energy flow distribution in the IES will be affected by energy consumption caused by local head loss, so it is necessary to calculate the energy flow with local head loss in mind. In this paper, a local head loss energy model at pipe connection is first established, then a solution model for the energy flow of the electricity-heat IES with local head loss model is established, and the model can be solved by N-R method. Finally, the effectiveness of the model and the influence of local head loss on the whole system are verified through case comparison. The result shows that energy loss caused by local head loss should be avoided although it's a small amount of energy for the whole system.