Performance Investigation of a Solar-driven Closed-wheel Desiccant Air-conditioning System

A solar-driven closed-wheel desiccant air-conditioning system is proposed to efficiently recycle the sensible heat and latent heat of regenerative exhaust air to solve the problem of exhaust air energy waste in traditional open-wheel desiccant air-conditioning systems. The system was modeled using TRNSYS software. Simulations were conducted to assess the influence of the cold-water flow rate ratio and fresh-air ratio on system performance and dynamic behavior. Additionally, an experimental device was built to verify the accuracy of the simulation model. The maximum relative error between the simulation results and the experimental results was ±9.8%. The optimal cold-water flow rate ratio of the system was determined to be 1∶5∶4. During the entire refrigeration season (1st June to 30th September) in Guangzhou, the average power COP_e was 2.4, the average thermal COP_th was 2.1, the harvesting water capacity was 25.66 t, and the heat recovery capacity was 9.70 MW. Compared with the solar-driven open-wheel desiccant air-conditioning system, the average COP_e and COP_th of the solar-driven closed-wheel desiccant system increased by 42.1% and 69.2%, respectively, and the CO₂ emission was reduced by 29.3%.