Volume 40: Energy Transitions toward Carbon Neutrality: Part III

Investigation on frost free air source heat pump system integrated with recirculated regenerated desiccant wheel Minqi Su, Xuan Wu, Yuanyuan Zhou, Xiaoqu Han, Jiping Liu, Junjie Yan

Abstract

In regions of southern China characterized by low winter temperatures and high relative humidity, frost-related challenges are frequently encountered by air source heat pumps. Traditional defrosting methods have been found to be inefficient and to yield unstable results. Therefore, an innovative frost-free air source heat pump system integrated with a recirculated regenerated desiccant wheel was proposed in this study. The impact of environmental temperature, humidity, and return water temperature on system performance were numerically investigated. Key performance indices, including inlet air humidity, system COP (Coefficient of Performance), and compressor output, were investigated. It was found that, when compared to conventional air source heat pump (ASHP) systems, a 40.3% increase in COP was achieved by the integration of the recirculated regenerative desiccant wheel. The system compressor output was significantly influenced by the ambient humidity (φamb). When absolute humidity surpassed 4.4 g·kg-1, the compressor output decreased with increasing φamb. Significantly, the system performance improvement was more pronounced in conditions of higher ambient humidity. A 10% increase in relative humidity resulted in a significant 3.7% increase in COP. In summary, this study substantiates the system’s reliability across diverse operating conditions, affirming its practical viability.

Keywords frost free, air source heat pump, desiccant wheel, recirculated regenerated