Exergoeconomic Analysis of District Heating Systems

District heating is a rational way to use fossil fuels for domestic heating (and cooling) in towns, especially if it is joined to a cogenerative production of electricity. The aim of this paper is to propose the use of exergoeconomic procedures for the design and analysis of district heating systems. Network design basically involves the selection of the areas to be connected to the network as well as the selection of some design variables as the pipe diameters, the location of pumps etc. This choice is operated assuming primary energy consumption as the objective function to be minimized. The application of these concepts is operated through a probabilistic approach derived from Simulated Annealing. An application to the Turin district heating system is presented here. The system is composed of a cogenerative combined cycle, some auxiliary boilers and the pipe network. An exergetic cost is associated to each user or potential user. This information is used to evaluate the opportunities for future expansions of the served area as well as the variation in some of the operating parameters.