THERMODYNAMIC ANALYSIS OF A LIQUID DESICCANT COOLING SYSTEM UNDER MEDITERRANEAN CLIMATIC CONDITIONS

摘要

Liquid desiccant air conditioning systems have recently been attracting attention, owing to their merits in handling the latent heat. Desiccant systems avoid not only the energy penalty caused by overcooling and reheating, but also the bacteria generation caused by condensed water. They can also significantly reduce the electricity peak load caused by conventional compression type air conditioning systems, especially in hot and humid regions. Desiccant systems are thus more energy efficient, healthy and environmentally friendly than conventional mechanical cooling. This paper presents the results from a theoretical study of a liquid desiccant system that provides air conditioning to a typical office building. A coupled heat and mass transfer analytical model was developed, based on the Runge-Kutta fixed step method, to predict the performance of the device under Mediterranean conditions. A parametric analysis was implemented to investigate the effects of ambient temperature and humidity ratio on the dehumidification mass rate, the load coverage and the thermal COP of the system. Simulation results showed that under hot and humid weather, the COP reaches its maximum value, 1.075. However, as the weather becomes more humid, the latent load coverage of the system is decreased and as it becomes hotter, the sensible load coverage of the system is decreased. The maximum latent load coverage, 91.8%, happened at 40°C, 0.011kg_w/kg_(da). Results can be useful for researchers and engineers. KEYWORDS Li