Advanced exergo-environmental analyses and assessments of a real district heating system with geothermal energy

This study is related to an environmental impact assessment of a district heating system with geothermal (DHS/G). For a real application, the Afyon DHS/G was selected. An advanced exergo-environmental analysis was used as an environmental assessment methodology. From the environmental aspect, it was divided into unavoidable/avoidable, exogenous/endogenous and further categories to evaluate the potential to improve system components and the interaction between the components. The environmental impacts of the exergy destruction and component-related features were evaluated according to certain markers, and possible suggestions for improvement were made to diminish the environmental impacts. The results of the study showed that the environmental impact of the system was lower than that of the wood-fired heating system. Furthermore, there has been a focus on the environmental impacts of the exergy destruction of components because of their low component-related environmental impacts. Environmental effects in many of the components were self-induced. Priority needs to be placed on improving heat exchangers. Some suggestions have been made to improve the design of heat exchangers. Finally, advanced exergo-environmental analysis allows us to evaluate the system components from the environmental point of view and provides information on the possibility of designing improvements.