Lzquierdo et al., (1997) presented a theoretical simulation of a lithium bromide absorption cooling system
they obtained a daily collector efficiency of about 35%, a daily COP of the cooling machine of about 55%
and a daily efficiency of the solar energy-cooling conversion of about 12%. Their analysis was made with
the introduction the new concept of a clear day; its daily level of solar energy is higher than the daily
threshold energy imposed by the process. The daily collector efficiency obtained by simulation was in
agreement with the experimental. . The daily global efficiency of flat plate collectors with a single cover,
was about 10% for a warm clear day and about 13% for very hot clear days, for the climatological
conditions in Madrid.
In recent years, research on solid absorption refrigeration has increased. Hawlader et al., (1993) investigated
a prototype solar assisted absorption cooling system. The liquid absorbents were lithium chloride or lithium
bromide with water as refrigerant. Experiments were conducted on an 11 m x 11 m collector/regenerator to
measure solution flow rates and concentrations at inlet and outlet, and temperatures at several locations of
the collector. A parametric study of the collector/regenerator performance enabled the identification of
important variables. Water evaporation rate is affected considerably by the solution flow rate, solar