Comparative Analysis of Compound Parabolic Concentrator Receptors Applied To Solar Cooling
Abstract
In the present work a comparative thermal study was realized. The comparison was limited to the receiver tubes of different materials for a specific compound parabolic concentrator (CPC), geometry. Inlet temperature range was selected from 30 to 70 °C and mass flow rate from 0.05 to 0.25 kg/s. The tests were performed with water as working fluid. Under these conditions, outlet temperature and irradiance were automatically recorded. Useful energy gain, absorbed solar radiation, overall heat loss coefficient and solar system efficiency were calculated. The CPC studied has an aperture area of 1.33 m2, a real concentration ratio of 3.5 and an acceptance half-angle of 15°. The outside tube diameter remained constant an equal to 0.06m (2”). The most suitable material was selected according to the experimental results. The specific CPC collector was designed to be applied as direct vapour generator of refrigerant. A theoretical model of a previously designed CPC (vapour generator) was coupled to an ammonia-water absorption refrigeration model in order to evaluate the performance of the complete refrigeration system. The absorption cooling system was designed for a 4.1kW cooling capacity. Low cost and easy manufacture make the developed CPC a good choice for low and medium temperature cooling applications in Mexico’s marginal zones, where energy supply is excessively expensive or even does not exist.