Thermally Enhanced Obstructed Flow Board for Hot Spot Mitigation

The next generation concentrated solar power (CSP) plants using falling particle receivers offer higher efficiencies which will reduce the levelized cost of electricity (LCOE) for this power source. These plants still have several challenges that must be addressed before commercialization and widespread use. One of these challenges include the durability of the obstructed flow board found in the obstructed flow falling particle receivers. At higher incident solar fluxes, the delicate mesh obstructions can melt due to hot spots. However, the higher the incident power, the greater the efficiency which makes these hot spots a threat to the highest possible efficiencies for next generation CSP plants. We propose to develop a thermally enhanced obstructed flow board to mitigate the hot spots generated due to the nonuniform solar flux. This thermally enhanced board will act as an enabling technology for the current obstructed flow board allowing it to receive higher incident powers and improve the receiver efficiency. In the Phase I program, the viability of the thermally enhanced board will be demonstrated through design and analysis, and the fabrication and on-sun testing of a sub-scale prototype. This includes modeling of the solar receiver incorporating the thermally enhanced board, a trade study of various two-phase technologies, and an economic analysis. A preliminary design of a full-scale system will also be developed utilizing the on-sun testing data collected for further development and maturation in Phase II. If successful, the technology developed in the Phase I and Phase II programs will provide an effective method of utilizing highly efficient two-phase heat transfer technologies in next generation concentrated solar power systems. These technologies are highly adaptable and can be employed in several CSP areas, including power generation and industrial process heat. The public benefit due to commercialization of this technology will be cheaper electricity from renewable solar energy sources.