Optimized Design of a Solar Concentrator Applied as Ammonia Vapor Generator in an Absorption Refrigerator

摘要

A detailed one-dimensional numerical model for describing the heat and fluid dynamic transport inside a compound parabolic concentrator (CPC) used as an ammonia vapor generator previously developed has been modified. The governing equations (continuity, momentum, and energy) inside the compound parabolic concentrator tube, together with the energy equation in the tube wall and the thermal analysis in the solar concentrator were solved iteratively in a segregated manner. Flow characteristics of the compound parabolic concentrator ammonia vapor generator (e.g. enthalpy, temperatures, pressure, heat fluxes, etc) were computed at each control volume. New compound parabolic concentrator geometries have been analyzed in order to show the model capabilities and optimize solar collection area, and to minimize manufacturing cost. Ammonia generator inlet working conditions were studied, and in some cases modified, by means of the thermal and fluid-dynamic numerical model developed in order to compare the ammonia vapor generation. CPC numerical designs with their respective results were coupled to a complete absorption refrigeration system model with ASPHN in order to evaluate its capacity and coefficient of performance.