Desiccant wheel combined with dual separated or single integrated heat pump? A comparison on energy consumption

Heat pump combined desiccant wheel systems have significant potential for industrial dehumidification. This study aims to define the usage boundaries between desiccant wheel systems combined with dual separated or single integrated heat pumps by selecting the most energy-efficient system configuration under various conditions. Two simulation models are developed to evaluate energy consumption under typical summer conditions. Moreover, Harbin, Beijing, Shanghai, Guangzhou, and Kunming are selected as representative cities to compare the energy consumption of two systems across five typical climate zones: severe cold regions, cold regions, hot summer/cold winter regions, hot summer/mild winter regions, and temperate regions. Meanwhile, the energy consumption of the two systems is compared under three indoor humidity control targets of 40 %, 30 %, and 20 %, and four indoor cooling load conditions ranging from 15 to 30 kW. The results indicate that the Single-HP system has lower energy consumption in severe cold, cold, hot summer/cold winter, and hot summer/mild winter regions, while the Dual-HP system is more suitable for climate zones with a lower outdoor humidity ratio. Moreover, the Single-HP system saves more energy when the indoor relative humidity is controlled below 20 %, while the Dual-HP system is more efficient under more relaxed humidity control requirements. In addition, regardless of indoor cooling load conditions, the Single-HP system consistently consumes less energy than the Dual-HP system with the energy consumption gap widening as the cooling load increases.