A NOVEL SOLAR INTERMITTENT REFRIGERATION SYSTEM FOR

A NOVEL SOLAR INTERMITTENT REFRIGERATION SYSTEM FOR ICE
PRODUCTION
1
W. Rivera*, 1G. Moreno-Quintanar, 2C. O. Rivera and J.F. Martínez
Centro de Investigación en Energía, Universidad Nacional Autónoma de México
A.P.34, 62580 Temixco, Mor., México
Abstract
A novel solar intermittent refrigeration system for ice production has been developed in the
Centro de Investigación en Energía of the Universidad Nacional Autónoma de México. The
system was designed to operate with the ammonia/lithium nitrate mixture for a maximum
capacity of 8 kg/day of ice. Because the lithium nitrate does not evaporate at the operating
conditions, a rectifier is not necessary in the system. The system consists of a cylindrical
parabolic collector acting as the generator during the generation phase and as absorber in
the evaporation one. The system operates exclusively with solar energy and no moving
parts are required. Several test runs were made for different solution concentrations varying
from 45% to 50%. Evaporator temperatures as low as - 8°C were obtained for a period of
time up to 8 hours. The coefficients of performance varied from 0.055 to 0.088 depending
on the solar radiation, the solution concentration and the ambient temperatures. The lowest
coefficients of performance were obtained at the lowest solution concentrations while the
highest were obtained at the solution concentrations of 49% and 50%. The system
developed proved to be a good technological alternative for ice production where electricity
supply is not available.