Study on performance optimization of a liquid desiccant air conditioning system driven by photovoltaic thermal–air source heat pump

Abstract

Compared to conventional condensation dehumidification systems, a solar liquid desiccant air conditioning system (SLDAC) offers distinct advantages, enabling independent control of temperature and humidity while operating at low carbon levels. This paper proposes a low-carbon SLDAC thermal mass exchange model that uses an indirect evaporative cooling liquid dehumidifier and photovoltaic thermal and air source heat pump for combined driving of the solution regeneration process. The system simulation model was created using MATLAB and TRNSYS software. An experimental comparison was conducted between the dehumidification module and the regeneration module, and the system's performance was simulated with an airflow of 150 m3/h in the Tianjin area. The results indicate an average dehumidification efficiency of 44.03% and a regeneration efficiency of 40.80% throughout the cooling season. During the cooling season, the power generation of the system met the power demand and produced a surplus of 85.36 kWh, achieving overall self-sufficiency in power consumption. The optimized system's operating parameters were proposed, with regeneration temperatures of 57 °C in June and September and 65 °C in July and August. During the cooling season, the system's regeneration capacity exceeded its dehumidification capacity for 84.90% of the operating time. As a result of optimization, the system's carbon emissions were reduced by 59.35%.