An environomic approach for the modeling and optimization of a district heating network based on centralized and decentralized heat pumps, cogeneration and/or gas furnace. Part II: Application

Applying the general environomic methodology presented in the first of this series of two articles (i.e. Part I [1]), details of the environomic model for a district heating network based on centralized and decentralized heat pumps are presented. A complete set of results for the optimal synthesis, design and operation of the network is given and discussed. The resulting solution space is highly nonlinear and noncontiguous and is effectively searched using a genetic algorithm. Results are shown for various district heating user distributions as well as fuel and electricity prices. When properly optimized, solutions with heat pumps are economically very close to traditional district hearing solutions, particularly when the main pollution costs are internalized. For comparison purposes, the same approach and models can be used to identify the life cycle exergetic optimum, which is also given. These results illustrate the power of this nem, engineering tool for the synthesis and design of more sustainable energy systems and networks. (C) 2000 Editions scientifiques et medicales Elsevier SAS.