A novel clustering based operating strategy of heat pump desiccant wheel system for low-humidity environments

Abstract

In various industrial manufacturing scenarios, maintaining a low humidity environment with a low dew point temperature (DPT) is crucial. Significant energy consumption is incurred during dehumidification processes. The Heat Pump Desiccant Wheel (HPDW) system emerges as an effective solution to regulate indoor temperature and humidity under such conditions. To improve the energy efficiency of HPDW systems, this study proposes a load clustering-based methods to optimize operation and develop tailored strategies. A comparative analysis of operating strategies and model-based optimization for a selected low-humidity environment is conducted. The results reveal that strategies integrating outdoor humidity ratio with hybrid conditions are effective in achieving the desired low humidity environment. Under these strategies, the system’s indoor humidity failure duration is reduced to 48 h and 197 h annually, respectively. The low-humidity environment can be maintained at a maximum indoor humidity ratio of 4.0 g/kg DA and 4.5 g/kg DA, respectively. Furthermore, the load clustering-based strategy successfully decouples control parameters and enhances the dehumidification performance, particularly during heating season and transitional seasons, through improved regeneration processes. Additionally, adopting a non-minimum outdoor air volume strategy achieves a notable 8.3 % energy savings, equivalent to approximately 15,000 kWh. When applying a strategy based on minimum outdoor air flow, maximum indoor humidity ratio of 3.89 g/kg DA and system’s failure duration of 7 h can be achieved. The design outdoor condition in Shanghai, with a temperature of 36.8 °C and a humidity ratio of 26.13 g/kg DA, can be selected as the most unfavorable input parameters for system design and operation during the cooling season. This study offers practical insights into optimizing HPDW systems for energy-efficient dehumidification in low humidity industrial environments.