Design Using Ray Tracing for a Solar Chemistry Test Module

Development is underway for modifications to an existing central receiver power tower concentrator solar power research facility to accommodate a new solar chemical test module. Optical analysis, using Sol Trace, is done to model the existing heliostat field, general tower geometry, and planned system layout to predict the incident irradiation to the new experimental receiver called the Solar Reducer Receiver Reactor (SR3). Within the SR3, a layer of particles flowing over an inclined plane will be highly irradiated to chemically reduce the particulate. To accommodate the inclined plane reactor geometry, a beam down mirror will be modeled. An estimated 1000 suns will be required at the aperture. Currently, the field typically provides around 300 suns over a 1 m × 1 m area. To achieve the required higher flux, a secondary concentrator will concentrate the irradiation from a larger area into a smaller focal spot. Rather than using an expensive compound parabolic design, a series of flat plate petals will instead be used to create a cost effective secondary. The flat plate design also provides added benefits for ease of installation, manufacturing, and cooling. The ray tracing model is used to compare several design parameters including the number of petals, petal length, aperture size and the inclination angle of the petals for the secondary. With these parameters selected, designs have been created for a test module to be constructed at King Saud University’s Riyadh Techno Valley CSP Tower. Additionally, the model is used to estimate the necessary cooling needed to operate both the secondary concentrator and the beam down mirror. These models will be tested experimentally using several quartz heaters. The beam down will be cooled by forced convection air, while the secondary concentrator will use water cooling. Lab experiments will measure the feasibility and effectiveness of the proposed cooling before construction. Once these proof of concepts tests have been completed, construction of the secondary concentrator and beam down mirror will begin to allow for testing in 2018.