Heat and mass transfer during adsorption of ammonia in a cylindrical adsorbent bed: thermal performance study of a combined parabolic solar collector, water heat pipe and adsorber generator assembly.

Author(s) : AGHBALOU F., MIMET A., BADIA F., et al.

Type of article: Article

Summary

In this article, the authors present a study on an adsorption refrigerator which uses an activated carbon-ammonia pair. The ability of activated carbon to adsorb large amounts of ammonia makes it ideal for use in adsorption refrigeration and pump systems. The efficiency of these systems is not high. In order to make these systems economically viable, their size must be reduced. This implies a need for a rapid heating and cooling of the adsorbent/refrigerant pair. However, the main problems to be overcome are related to the poor heat transfer in the adsorbent bed. So, it is necessary to study and understand the heat and mass transfer within the bed and to improve it. A detailed model of heat and mass transfer in the generator has been developed. For a given heat flux, temperature and adsorbed mass have been computed in every point at each step time along the adsorbed bed (generator). An experimental installation simulating an adsorption machine working within a temperature ranging from 20 to 250 °C allows for identification of the generator's equivalent thermal conductivity and internal heat transfer coefficient. These two parameters were then used to simulate the thermal performance of a design whose features include the insertion of stainless steel water heat pipe (HP's) condensers in the generator. The HP evaporator heat input is of solar origin using a compound parabolic collector (CPC). The nominal solar coefficient of performance, COP= 14.37% obtained through both Adimensional Exergy Loss (AEL), and a COP study, shows the competitiveness of the proposed design.

Details

  • Original title: Heat and mass transfer during adsorption of ammonia in a cylindrical adsorbent bed: thermal performance study of a combined parabolic solar collector, water heat pipe and adsorber generator assembly.
  • Record ID : 2005-0697
  • Languages: English
  • Source: Applied Thermal Engineering - vol. 24 - n. 17-18
  • Publication date: 2004/12

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