Testing and Simulation of a Solar Diffusion-Absorption Refrigeration System for Low-Cost Solar Cooling in India
Abstract
Solar cooling technologies have the potential to improve crop and vaccine supply chain management in areas with unreliable access to an electricity distribution network. The diffusion absorption refrigeration (DAR) cycle is a technology of interest for cooling in rural areas and developing countries due to its low capital cost, low maintenance requirements, and unique design in which the requirement for electrically-driven components are fully omitted. The main feature of DAR systems is a thermally driven bubble pump that is used to circulate the refrigerant and absorbent fluid components around the system. In this paper, we present results from a laboratory DAR system operating over a range of pressures and heat input rates with ammonia-water-hydrogen as the working fluid. By reducing the system pressure from 21 bar to 14 bar, a 17% increase in maximum coefficient of performance (COP) is reported, and the system start-up time is reduced by up to 58%. The results are used to calibrate a thermal model of a solar-DAR system, which is then used to determine the optimal system pressure and solar collector array configuration for summer operation in the location of Chennai, India.