Paper Conference

Proceedings of BSA Conference 2015: Second Conference of IBPSA-Italy


A multi-objective optimization analysis on high-performance buildings connected to district heating-CHP system

Dario Prando, Alessandro Prada, Fabian Ochs, Andrea Gasparella, Marco Baratieri

Abstract: The European energy policy is strongly promoting the refurbishment of buildings and this affects the energy and economic performance of the district heating (DH) systems. The refurbishment of buildings connected to a DH system leads to the under-utilization of the DH capacity. This paper aims to define the energy and economic performance of a district heating (DH) considering the impact of cost-optimal refurbishment solutions of the connected buildings. For this purpose, an integrated model for both buildings and network has been developed. Several refurbishment measures for the existing buildings have been investigated and a multiobjective (energy and economic) optimization has been conducted, by means of a genetic algorithm. The possibility to shift to a low-temperature DH and the implementation of a CHP system have been investigated as feasible solutions to compensate for the loss of performance of the network. The results highlight that the building refurbishment strongly influence both the energy and economic performance of the DH system. The DH performance is considerably low when a high number of refurbished buildings is considered in the district. The implementation of the minimum network temperature allows for a partial compensation for both the energy and the economic losses deriving from the refurbishment. However, this measure is not sufficient for a profitable DH. The installation of a CHP system in the network, thanks to the revenue from the electricity trade, allows for a profitable operation of DH network with a heat density of 0.15 MWh (m year)-1. Although the installation of a CHP system is economically convenient, its primary energy saving (PES) index is negative for such a micro DH networks.
Pages: 537 - 545