Performance of a new solid adsorption ice maker with solar energy regeneration

A predictive model for an adsorption solar cooling system using the activat ed carbon-methanol pair and its numerical simulation are presented. This mo del accounts for instantaneous heat and mass transfers in each one of the m achine components along a characteristic average day for each month. The so lar powered ice maker consists of the following basic components: a reactor containing an adsorptive bed coupled to a static solar collector covered b y Transparent Insulation Material (TIM), a condenser and an evaporator. A u niform pressure model for the reactor is considered. The bed's radial tempe rature distribution is determined by means of a one-dimensional numerical m ethod based on a finite difference technique. The machine's performance is evaluated according to meteorological data valid for the hottest six months in Joao Pessoa (7 degrees 8'S, 34 degrees 50'WG), whose climate is typical ly hot and humid. The results are compared with those obtained from an iden tical system with a single cover solar collector. These last data are then compared to the results obtained in a particular month from the experimenta l study of a prototype with equivalent components, tested in Tunisia. The T IM cover's system proved to be about 40% more efficient than the single cov er solar system. The average net solar COP was 0.13 for the TIM cover syste m during the six month considered period. This corresponds to 7-10 kg/day o f ice production per square meter of solar collection surface, respectively , for March and December, with solar irradiations ranging from 20 to 23 MJ/ m(2), during the October-March period. (C) 2000 Elsevier Science Ltd. All r ights reserved.