Thermoeconomic analysis of a novel topology of a 5th generation district energy network for a commercial user

This research compares an existing 4th generation heating and cooling network with a novel 5th generation heating and cooling network, driven by renewables. The networks are designed to cover the energy demand of a large shopping center. The existing network uses the thermal energy recovered from a trigenerative reciprocating engine coupled with an absorption chiller, to supply the heating and cooling networks. The proposed renewable 5th generation network consists of two neutral rings: the first one is the cold sink for the water-to-water heat pumps, installed in the substations; the second one is the hot sink for the heat pumps installed in the substations. One of the main novelties of the proposed layout consists in the use of a heat exchanger between these two rings. This heat exchanger recovers the heat rejected by the condensers of the heat pumps operating in cooling mode, supplying the evaporators of the heat pumps operating in heating mode. A photovoltaic field equipped with a lithium-ion battery partially matches the electricity demand of the network. The models of the shopping center and the existing and proposed networks are developed in TRNSYS environment. The proposed system achieves promising results: renewable electricity matches roughly 89% of the shopping mall electricity load can be covered by renewable power.