HP2035: Performance Assessment of Natural Refrigerants in Heat Pumps for Micro-district Heating
Residential heating is a major contributor to final energy consumption and emissions in the EU. As the EU strives to meet carbon neutrality goals by 2050, improving the efficiency and sustainability of residential heating systems is a critical priority. Transitioning to low-carbon technologies, such as heat pumps and district heating networks, is essential for reducing emissions, enhancing energy security and improving resource efficiency. Conventional district heating networks often rely on flue gas heat recovery from combustion plants, and decentralized heat pump systems that use ambient air as heat source can suffer from reduced efficiency in cold or fluctuating climates. The deployment of heat pumps into microdistrict heating networks can be a viable solution to mitigate these challenges, particularly by utilizing local heat sources to maximize system efficiency under cold ambient conditions. Dual-source heat pump can dynamically combine heat sources, such as ambient air and urban waste heat, to enhance seasonal performance, and reduce compressor work during peak demand. This study investigates the seasonal performance of a dual-source heat pump system in a micro-district heating using natural refrigerants. The study compares the performance of natural refrigerants, low-GWP alternatives aligned with EU regulatory frameworks, with conventional HFC-based systems. A numerical simulation was conducted to assess the system’s behavior under varying ambient conditions and heating demands. Results demonstrate that dual-source configuration enhance system efficiency under low ambient temperature, and natural refrigerants can outperform conventional HFC-based systems in practical scenarios. Including a secondary heat source improved the COP up to 30%. Ammonia exhibited the highest SCOP. While the dual-source configuration introduces additional complexity, The outcomes highlight performance improvement at lower temperatures and suggest strong potential for future applications in urban heating networks. This study contributes to ongoing decarbonization efforts and encourages further development and integration of dual-source systems within future micro-district heating networks.