[Objective

]

To improve the efficiency of concentrated solar power(CSP)

a novel rotating cavity receiver was proposed for dish-type solar thermal systems. [Methods

]

The Monte Carlo method was adopted to develop a precise ray-tracing model that comprehensively simulated the entire process of solar rays from initial emission to final absorption. Based on the ray-tracing results

the solar radiant energy absorbed by the inner wall of the receiver and the outer wall of the heat absorption tube was mapped onto each grid cell of the corresponding wall surfaces via a user-defined function

thus obtaining the thermal boundary conditions of the wall surfaces for subsequent import into computational fluid dynamics(CFD) software. Accordingly

a three-dimensional numerical simulation model of the receiv

er with its surrounding computational domain was established regardless of wind effects. The optical and heat transfer characteristics of the novel rotating cavity receiver

including optical efficiency

heat flux

temperature distribution

and various losses

were systematically analyzed under different operating parameters

in which the direct normal irradiance(DNI) ranges from 700 to 900 W/m

2

and the angle(angle γ) between the aperture axis and the spiral coil axis varies from 0 to 75°. Finally

to validate the reliability of the numerical simulation results

an experimental setup was constructed and tests were carried out under several typical operating conditions

followed by a comparison between the experimental data and the simulation results. [Results

]

The results show that the optical efficiency is independent of DNI but decreases from 98.5% to 97.8% as the angle γ increases. With a larger angle γ

more solar rays are incident on the inner wall of the rotating cavity

leading to an uneven temperature distribution inside and outside the receiver

accompanied by a significant increase in both the area of the high-temperature region on the rotating cavity inner wall and the maximum temperature of the tube wall. Heat losses via heat conduction

convection

and radiation increase with DNI and γ

among which the radiation and convective heat losses are markedly more sensitive to variations in γ. When γ is relatively large

the radiation and convective heat losses increase considerably

resulting in a substantial decline in both the heat collection efficiency and the overall efficiency. [Conclusion

]

The novel rotating cavity receiver exhibits superior solar-thermal conversion performance

achieving optical efficiency above 97%

heat collection efficiency above 80%

and overall efficiency above 70%. These research findings provide a valuable reference for the design of large-scale dish-type solar power systems.