Design and experimental testing of the performance of an outdoor LiBr/H2O solar thermal absorption cooling system with a cold store

2010

English

A domestic-scale prototype experimental solar cooling system has been developed based on a LiBr/H2O absorption system and tested during the 2007 summer and autumn months in Cardiff University, UK. The system consisted of a 12 m2 vacuum tube solar collector, a 4.5 kW LiBr/H2O absorption chiller, a 1000 l cold storage tank and a 6 kW fan coil. The system performance, as well as the performances of the individual components in the system, were evaluated based on the physical measurements of the daily solar radiation, ambient temperature, inlet and outlet fluid temperatures, mass flow rates and electrical consumption by component. The average coefficient of thermal performance (COP) of the system was 0.58, based on the thermal cooling power output per unit of available thermal solar energy from the 12 m2 Thermomax DF100 vacuum tube collector on a hot sunny day with average peak insolation of 800 W/m2 (between 11 and 13.30 h) and ambient temperature of 24 °C. The system produced an electrical COP of 3.6. Experimental results prove the feasibility of the new concept of cold store at this scale, with chilled water temperatures as low as 7.4 °C, demonstrating its potential use in cooling domestic scale buildings.

Agyenim, F.; Knight, I. P.; Rhodes, M.