Enhancing Temperature Optimization and Economy in a Danish District Heating Network through Domestic Hot Water Substation Renovation

Large apartment buildings with storage tanks (or heat exchangers) and domestic hot water (DHW) circulation systems are critical for minimizing district heating (DH) network operating temperatures. Investigating the potential for temperature optimization across the entire network, innovative DHW substations with circulation booster units were introduced in a critical mass of buildings within an urban area of Viborg. Results indicate a potential reduction in the supply temperature by 4.6°C and up to 0.43°C for the return temperature. This reduction in network temperatures yields significant financial benefits, including lower heating prices for end-users, alongside improved energy generation and reduced distribution losses for the local municipally-owned DH company. Furthermore, the study evaluates the conventional user-owned business model for the substation and proposes an alternative company-owned model, offering insights into their respective implications for stakeholders.