Temperature Control of Solar Air Conditioning Systems

This thesis investigates the problem of regulating the temperature of a conditioned space using a Solar Assisted Air Conditioning Systems (SAACS) prototype located at Cabo Rojo, Puerto Rico. The SAACS Prototype consists of a 66 flat plate solar collector array with 115.4 m 2 of selective surface area, a 35 kW single-effect lithium-bromide absorption chiller, a 84 kW cooling tower, a 50 kW auxiliary hot water boiler, a 5700 liter storage tank equipped with flexible stratification manifolds, and a 1800 l/hr air-handling unit. A discrete-time state-space model of the absorption chiller and a linear model of the plant to be controlled (the conditioned space) are identified and presented. Experimental data was used for the determination of these models. A temperature controller was designed and applied to the plant model. This controller operates the absorption chiller under multiple load conditions and regulates the flow in the chilled water line based on the conditioned space requirements. The designed controller was implemented in the SAACS prototype. The system's performance under this temperature controller is analyzed and the results are presented and discussed. Dedication To my mother Maria Nancy and my Grandmother Bertha Lucia (God is with her), for their unconditional support, since no one have sacrificed more to see me achieve my goals. To my brothers, and Julian David, whom I love so much. Finally to my nephew " Dieguito " , for making my life happier when I am in Colombia.