Simulation and analysis of a meshed district heating network

Abstract

The flow distribution in a district heating network tends to become no longer obvious when system design is developed and its complexity increased. As a consequence, the network owner, often the local energy company, is in need of a simulation program to have the possibility of analysing network behaviour and expand the understanding about the operation of district heating system. In this paper, a simulation tool developed in MATLAB/Simulink is applied in order to analyse the flow distribution in the district heating network of the town of Kiruna (Sweden). The network in Kiruna has been developing since the 60s and is today a complex network with a meshed structure, i.e. it is formed by a set of loops from which secondary branches depart. The simulation tool is part of a methodology that has specifically been developed to analyse the flow pattern in such kind of networks without altering their physical structure, and it is expected to be a valuable tool for the redesign of the network in the forthcoming relocation of some of the urban districts. The results about the current network configuration show that only a few pipes in the network are exceeding the levels of heat flow recommended by pipe manufacturers. The largest drops in pressure and temperature from the heat production site to the nodes serving the main consumer areas are within 1.2bar and 9°C in the days of highest demand.