High Flux Microscale Solar Thermal Receiver for Supercritical Carbon Dioxide Cycles

Abstract

Characterization of a microchannel solar thermal receiver for a supercritical carbon dioxide (sCO2) is presented. The receiver design is based on conjugate computational fluid dynamics and heat transfer simulations as well as thermo-mechanical stress analysis. Two receivers are fabricated and experimentally characterized — a parallel microchannel design and a microscale pin fin array design. Lab-scale experiments have been used to demonstrate the receiver integrity at the design pressure of 125 bar at 750°C surface temperature. A concentrated solar simulator was designed and assembled to characterize the thermal performance of the lab scale receiver test articles. Results indicate that, for a fixed exit fluid temperature of 650°C, increase in incident heat flux results in an increase in receiver and thermal efficiency. At a fixed heat flux, efficiency decreased with an increase in receiver surface temperature. The ability to absorb flux of up to 100 W/cm2 at thermal efficiency in excess of 90 percent and exit fluid temperature of 650°C using the microchannel receiver is demonstrated. Pressure drop for the pin array at the maximum flow rate for heat transfer experiments is less than 0.64 percent of line pressure.

Dry Reforming in a Milli-Scale Reactor Driven by Simulated Sunlight

“…Light passes through the opening and is delivered to the receiver located underneath the mask. More information about the solar simulator design and flux calibration procedure can be found in the work by L'Estrange et al [23].…”

“…Light passes through the opening and is delivered to the receiver located underneath the mask. More information about the solar simulator design and flux calibration procedure can be found in the work by L'Estrange et al [23]. In situ temperature measurements were impractical during reactive testing as a result of the small dimensions, so a preliminary test of the thermal behavior of the milli-scale reactor was performed.…”

Numerical Investigation of Heat Transfer and Flow Characteristics of Supercritical CO2 in Solar Tower Microchannel Receivers at High Temperature

“…Moreover, the buoyancy and thermal acceleration effects were weakened as the inlet velocity increased in both downward and upward flows, and they were strengthened due to the increased heat flux. Oregon State University [17,18] developed the microchannel solar tower receivers for supercritical CO 2 using an array of modular microchannel cells. Two structural unit cells of a parallel microchannel design and a microscale pin fin array design were fabricated in 2 cm × 2 cm, and the experiments were conducted.…”