Performance analysis of hybrid solid desiccant–vapor compression air conditioning system in hot and humid weather of India

Abstract

The performance of hybrid solid desiccant–vapor compression air conditioning system is studied for the typical hot and humid climatic zone of North India (Roorkee). The system consists of a rotary desiccant dehumidifier coupled with heat recovery wheel and a conventional vapor compression air conditioning system. A FORTRAN program was developed to calculate different psychrometric properties like humidity ratio, dry-bulb temperature, wet-bulb temperature, relative humidity, specific heat, etc. at each state point of the system on the basis of ambient and desired inside room conditions, room cooling load, sensible heat factor, and required air flow rate. The overall system performance has been evaluated in terms of the coefficient of performance and the dehumidifier effectiveness. The influence of variation in ambient conditions on regeneration temperature of desiccants has also been discussed. The simulated results are validated using experimental measurements. The present system has ensured a reduction of 79.15% in processing air humidity ratio at an outlet of the desiccant dehumidifier as compared to the outdoor humidity ratio. The results show that the performance of the system is significantly affected by the variations in ambient temperature and humidity ratio.

Practical application : The proposed model of solid desiccant–VCR hybrid air conditioning system minimizes the energy usage in comfort cooling applications such as auditoriums, supermarket, hospitals, central library, offices, and lecture halls in hot and humid climate while maintaining an acceptable thermal comfort level and improving the performance. The proposed approach will give valuable insights to the researchers and building engineers to analyze the impacts of ambient conditions on the energy requirements and performance of solid desiccant cooling to ameliorate comfort, energy, and cost savings. Moreover, its potential contribution in environmental protection makes it more attractive at a time where depletion of energy resources and environmental degradation are of major concerns.