Study on radiation transfer characteristics and thermal properties in a concentrated solar solid particle receiver based on Monte Carlo method

This study developed an analysis scheme that combines CFD-DEM (Computational Fluid Dynamics - Discrete Element Method) simulation, the Monte Carlo method, and one-dimensional analysis to study the radiative transfer characteristics and heat performance of concentrated solar solid particle heat receivers. Firstly, a CFD-DEM simulation of the gas-solid flow field within the receiver is conducted to determine particle position. Subsequently, the Monte Carlo ray tracing method is employed to obtain the spatial distribution of radiative properties. Finally, a one-dimensional steady-state heat transfer model is utilized to investigate the influence of various parameters on receiver performance. The results indicate that the optical properties of the particle curtain exhibit an approximate semi-parabolic distribution in the thickness direction, while the absorptivity diminishes with increased particle fall distance. As the particle mass flow rate increases, the curtain’s absorptivity rises from 3.467 % to 33.593 %. The absorptivity is quadrupled for particles with a diameter of 300 μm compared to those with a diameter of 1000 μm. Reducing particle diameter and increasing particle absorption coefficients lead to increased temperature rise and higher thermal efficiency of the particle curtain. Increasing the mass flow rate lowers the net absorbed radiation per unit mass while simultaneously improving the receiver’s overall thermal efficiency.