Feasibility analysis of solar-air source heat pump coupled with sand-based thermal storage floor in various rural regions, China

Le résumé fourni par la source

Developing efficient renewable heating with thermal energy storage is vital to replace scattered coal, especially in rural China. Although phase change materials currently dominate research efforts, systems utilizing low-cost storage medium such as sand present a more sustainable alternative. However, the climatic applicability and key parameters of such systems remain poorly characterized, impeding their widespread adoption. This study investigates the impact of climate, sand-based thermal storage floor (SBTSF) configuration, operational strategies, and capacity parameters on the performance of a solar-air source heat pump system with sand-based thermal storage floor (SASHP-SBTSF) employing a validated model developed by Transient System Simulation Tool (TRNSYS). Results indicate that the SASHP-SBTSF heating system achieves a coefficient of performance (COP) exceeding 2.2 in both severe cold and cold regions. However, the indoor temperature guarantee rate fails to meet requirements in severe cold region B and C (solar resource class III). Combined with economic analysis, the system is suitable for cold regions and severe cold region C (solar resource class II). SBTSF configuration has limited impact on system energy consumption, solar fraction (SF), and COP, but significantly affects its thermal response behavior. The air source heat pump (ASHP) startup temperature has a greater impact on system performance than the temperature difference between the collector outlet and the water tank, with this effect varying by regions. Among equipment parameters, collector area has the most significant influence on system performance. Although increasing water tank volume and ASHP heating power can improve system performance, regional variations indicate that neither parameter should be excessively enlarged. Through multi-climate analysis, this study clarifies regional applicability of the system and proposes optimized parameters and operation strategies, providing a foundation for designing clean heating systems tailored to diverse rural climates and supporting energy conservation and emission reduction efforts.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.