Wind load analysis of a new linear Fresnel receiver assembly design

Abstract

A linear Fresnel collector includes a low-profile reflector array and a receiver assembly with one or more absorber tubes and an optional secondary reflector. This combined optical system concentrates sunlight and converts it into thermal energy. The design of a receiver assembly is critical to the performance of a linear Fresnel collector. A position deviation of a few centimeters for the receiver assembly can result in notably reduced performance, thus leading to a direct loss in revenue associated with thermal power production. Wind load is one of the most significant environmental factors that can alter the optical—and therefore thermal—performance of a solar power system due to displacements after installation. At the same time, an over-designed receiver assembly may add unnecessary construction cost to a typically high-cost-constrained system. Thus, wind load analysis is particularly important when considering optimal engineering design of a receiver assembly and its supporting structure to cost-effectively mitigate the impacts of wind. In this study, a detailed computational fluid dynamics (CFD) model is adopted to derive the wind load of a commercial linear Fresnel receiver assembly. This wind load is then used as a reference to optimize the detailed engineering design. The CFD model is first carefully developed and benchmarked within a critical regime toward turbulence. The drag force, lift force, and vortex-shedding frequencies are derived at both the operating and survival wind-speed limits for target project deployment locations. The wind load analysis results provide a valuable reference for future engineering design and prototyping.

Investigation of temperature distribution on a new linear Fresnel receiver assembly under high solar flux

“…On the other hand, because of flow recirculation in the space between the secondary reflector and glass envelope, the right bottom portion (270 o ‐360 o ) of the glass envelope experiences a greater temperature reduction, as shown in Figure B. A detailed wind‐load analysis of the Hyperlight receiver assembly at higher wind velocities can be found elsewhere . These results indicate that the design‐point no‐wind condition represents a worst‐case high‐temperature condition for material selection and that lower material temperatures can be expected under realistic operating conditions with even slight external wind.…”

“…Each reflector is 4 inches wide and carried by a plastic tube floating in a water basin, and each basin can accommodate 50 reflectors. Detailed design information can be found elsewhere . The total net reflector width is about 10.5 m.…”

“…Detailed design information can be found elsewhere. [32][33][34][35] The total net reflector width is about 10.5 m. Figure 2B illustrates the receiver assembly including an evacuated receiver tube and a secondary reflector. The geometrical specifications of the receiver assembly are summarized in Table 1.…”

“…A new receiver assembly design is being developed by the National Renewable Energy Laboratory (NREL) and Hyperlight Energy (Hyperlight) . The design uses an evacuated receiver and secondary reflector, with a design point output fluid temperature of 400°C.…”

“…[27][28][29][30][31] A new receiver assembly design is being developed by the National Renewable Energy Laboratory (NREL) and Hyperlight Energy (Hyperlight). [32][33][34][35] The design uses an evacuated receiver and secondary reflector, with a design point output fluid temperature of 400°C. The profile of the secondary reflector is optimized using a newly developed adaptive method.…”