Transient simulation of solar desiccant/M-Cycle cooling systems in three different climatic conditions

Abstract

Solar desiccant cooling systems have been recently introduced as the more efficient systems for air conditioning the buildings, especially in hot and humid areas. In this paper, the performance of three new configurations of solar desiccant cooling systems integrated with the Maisotsenko cycle is numerically investigated using TRNSYS software. The monthly variations of supply air temperature and humidity ratio are presented using the proposed cooling systems under three different climatic conditions (Moderate and Humid, Hot and semi-Humid and Hot and Humid). Results show that the lowest supply air temperature (below 16°C) is obtained by the solar desiccant cooling system that used two M-Cycles in the supply and return streams. Because of higher solar radiation in Hot and semi-Humid climate, a major contribution to the thermal energy input to regenerate the desiccant wheel is provided from the sun. The cooling capacity and COP reduces in Hot and Humid climate than the other two climatic conditions because of the higher humidity ratio of the ambient air. The highest COP is obtained using the system by two M-Cycles in Moderate and Humid climate, which is on average 0.728. It is also found that by increasing the regeneration temperature from 100°C to 120°C, the COP of the solar desiccant cooling system with two M-Cycles reduces about 53% (from 1.28 to 0.6). The findings indicate that, in all considered climatic conditions, the solar desiccant cooling systems integrated with M-Cycle show better cooling performance than those integrated with the evaporative cooler.