Operational performance of heat pump desiccant wheel system in low humidity industrial environment: On-site measurements and model based optimization

In order to optimize the operational performance a heat pump coupled desiccant wheel (HPDW) system in a manufactory, on-site measurement and simulations were conducted. On-site measurements reveal that the system's coefficient of performance (COPsys) ranges from 1.29 to 1.38 under typical summer conditions, and from 0.28 to 0.32 under typical winter conditions. The unit effectively provides air with a dew point temperature below −3 °C, achieving an indoor humidity ratio of less than 3.47 g/kg. Simulations reveal that joint optimization of the operating parameters enables more precise control of the indoor environment, thus realizing energy savings. Specifically, energy savings of 10.9 %, 30 %, 17.7 %, and 3.1 % are achieved under four distinct operating conditions in summer and winter, respectively. The optimum indoor temperature and humidity ratio in summer are determined to be 18–19 °C and 3.3–3.47 g/kg respectively in order to fully utilize the advantages of pre-cooling heat pump. Due to limitations in supplemental heat forms during winter, the optimal control ranges for temperature and humidity in winter are established at 10–12 °C and 3–3.47 g/kg, respectively. This study thus offers valuable guidelines for the design and operational parameters of HPDW systems, ensuring improved performance and energy efficiency across different seasonal conditions.