An Experimental and Numerical Study on the Heat Transfer Driven Dynamics and Control of Transient Variations in a Solar Reactor

University of Minnesota M.S.M.E. thesis.July 2019. Major: Mechanical Engineering. Advisor: Nesrin Ozalp. 1 computer file (PDF); xiv, 156 pages.There is a major challenge in utilization of concentrating solar power for stable energy conversion processes due to fluctuating nature of available irradiation. This challenge can be handled by development of a robust control system that is capable of absorbing fluctuations in the sun’s irradiance without significantly changing the flow dynamics. In this thesis, a heat transfer driven model predictive control system is developed for advanced control of changes in solar flux by implementing a heat exchanger coupled variable aperture mechanism to capture spilled radiation. Experimental testing of the system was performed using a new 10 kWe xenon arc high flux solar simulator which was fully characterized in this thesis. Experimental results showed that the aperture mechanism can maintain the temperature of the reactor within ± 5 °C under severe radiation fluctuations during a cloudy day. Therefore, the aperture mechanism is a promising alternative to current traditional temperature control methods