Optimization of polygeneration plants and μ-grids for civil applications

Abstract

The problem of combined energy production and distribution of warm and cold fluids is very complex because it includes two possible configurations, the small single unit for individual buildings and the large plant integrated with district heating networks. Dealing with such a complex problem, involving a very large number of variables, requires efficient algorithms and resolution techniques. The present study illustrates a MILP approach to the optimization of synthesis, design and operation for CHCP-based μ-grids including thermal energy storages. The proposed approach develops a method for designing and optimizing district energy systems, starting with the information available for the district such as energy consumption profiles, location of the buildings, energy resources to be consumed, possible layouts for the pipes and the design of the network, to provide economic model of the energy conversion technologies, and routines oriented to simulate the operation of the system and finally select the design that achieves optimal economic results. The method is validated by applying it to a case study represented by a cluster of buildings interconnected by a heat network and situated over a small area (maximum distance in the order of 1.5 km). The results obtained, have been verified with the data of daily consumptions, confirming the validity of the proposed methodology.