Performance comparison of solar-driven single and double-effect LiBr-water vapor absorption system based cold storage

The solar-assisted vapor absorption system provides a promising alternative to the vapor compression system for cold storage applications. In the present work, a comparative performance assessment of a single-effect and a double-effect vapor absorption system has been carried out for the operation of a cold storage facility. The proposed cold storage is powered through a combination of a grid-interactive solar photovoltaic system and parabolic trough collectors. A thermal model of the VAR systems is developed based on the first law and the second law of thermodynamics. An economic model has also been developed to compute the payback period. The maximum coefficient of performance of the double-effect VAR system (for the present case) for a calendar year is found to be 1.32, which is about 80% higher than that of the corresponding single-effect system. Also, the exergy efficiency of the double-effect VAR system is estimated to be about 16% higher than that of the singleeffect system. The payback period of the double-effect VAR system-based multi-commodity cold storage powered through the solar thermal-PV system is found to be about six months lesser than the corresponding single-effect system. Thus, the double-effect VAR system is a more feasible option to operate a cold storage facility from the energy, exergy, and the economic point of view.