Design and Operational Experiences of an Alternative Heat Rejection Sink for an Existing Absorption Solar Cooling System
Abstract
The paper focuses on a critical issue of the solar cooling facilities based on absorption chillers. The heat rejection system of this kind of chiller is a key factor because the condensation and absorption temperatures will affect the COP and the cooling capacity. The paper describes the performance of a solar cooling installation located in Zaragoza (Spain). The solar cooling system consists of 37,5 m2 of flat plate collector, a 4,5 kW, single effect, LiBr-H2O rotary absorption chiller and a dry cooler tower. The installation, designed to mitigate the overheating problems in the existing solar collectors, is being monitored and provides cooling to a gymnasium belonging to the sports center of the University. In the last three years, 2007, 2008 and 2009, several studies have been carried out to analyze the full system operation. In the first two years, the measured data showed the strong influence of the cooling water temperature on the COP. Based on these results, a geothermal sink for heat rejection was studied and installed. The paper shows the results of the system performance in its first year of performance with the new heat rejection sink, and compares them with its dry cooler performance.