Development and testing of a prototype of low-power water–ammonia absorption equipment for solar energy applications

This article outlines the development and testing of a prototype of a water–ammonia absorption system designed for solar-powered refrigeration in small rural operations. The objective is to design a 2 kW refrigeration equipment for isolated areas with a high level of solar radiation to meet refrigeration requirements. The equipment has been designed to operate with a concentrating solar power system to obtain the required temperatures. The heat exchangers, which act as condensers, as well as the absorber and evaporator, are all made of galvanized steel piping having fins. The design uses natural convection; the generator and energy-saving heat exchanger have a multi-tubular arrangement and a transfer tank is used in place of a pump for displacing the ammonia solution. All of the operations are manually controlled. Overall, the test results showed unsatisfactory operation of the equipment having low efficiency. Nevertheless, the proposed objectives have been met and it is evident that with several important modifications the equipment will operate satisfactorily. In conclusion, based on the development phase, it is apparent that future prototypes must be more compact and more efficient.