Modeling approach and simulation study to assess the utilization potential of industrial waste heat in district heating systems

Abstract

Companies and nations are developing strategies to reduce CO2 emissions and achieve their climate goals. Due to their high share of final energy demand, heating and cooling supply systems are of crucial importance regarding emission reduction. Here, especially the industrial and building sector have a dominating influence, accounting for 34% and 33% of the global final energy demand. Aside from reducing the energy demand or integrating renewable energy sources, the utilization of industrial waste heat represents an effective approach to minimize CO2 emissions in heating supply systems. Here, the coupling of the building and industrial sector via district heating systems offers the potential to utilize industrial waste heat. As the utilization is highly dependent on temperature levels and temporal occurrence, modeling approaches to evaluate the site-specific CO2 emission reduction potential must be developed. To consider heterogeneous industrial heating and cooling supply systems as well as the dynamic occurrence of industrial waste heat and energy demands, we present a tailored modeling approach. The approach enables to model configurable industrial heating and cooling supply systems which can be coupled to district heating systems via an industrial heat transfer station. The simulation models consider different energy converters, temperature levels, as well as waste heat sources. Within our research, different configurations are tested through a simulation study and evaluated by an integrated environmental and economic evaluation module. The simulation study, based on industrial thermal load profiles, shows a maximum waste heat utilization of 66% and a corresponding CO2 emission reduction of 39%, with regard to the industrial site’s emissions. The coupling with a district heating system can reduce the industrial site’s operating expenses by up to 14 %. However, the allocation of the overall economic benefit is dependent on the assumed heat price.