Dynamic simulation of a 4th Generation District Heating network with the presence of prosumers

Abstract

District Heating Network is identified as a promising technology for the decarbonization of urban areas. Thanks to the surplus of heat available from distributed renewable energy plants, a typical heat consumer of the network could become an energy producer during the day (typically referred to as “prosumer”). Models for thermal grids developed during the years usually assumed a centralized heat production. The increasing presence of prosumers will require accurate dynamic modeling to monitor the changes induced in the thermohydraulic variables of the network. To fill this knowledge gap, this paper aims at developing a model of a thermal grid with prosumers in TRNSYS environment. The model allows for monitoring the main thermohydraulic parameters of the system and calculating the achieved energy and emissions saving due to reduced generator and pumping consumption. As an example, the study assumes a ring-shaped network serving a cluster of 10 residential users located in Palermo (Italy). Different scenarios are proposed based on the presence of prosumers along the network and cooling by an absorption chiller is assumed. Results show a 26.1 % and 52.2% reduction in thermal losses when the temperature of the network is decreased from 100 ° C to 80 °C and 60 °C respectively. Moreover, the presence of prosumers could lead to an 18.7 % reduction in the energy produced by the centralized plant, and a 28.5% reduction in energy consumed for pumping.