Error Analysis of Infrared Temperature Measurement for 3D Non-Isothermal Porous Layer

In the application of solar porous receivers, a numerical 3D model for infrared temperature measurement of non-isothermal porous layer with anisotropic scattering is developed based on the reverse Monte Carlo method. The effects of scattering event, layer thickness, material emissivity, porosity and pore diameter on the measurement error are investigated. A procedure to calculate the surface temperature of porous materials is proposed. The results show that a notable error occurs between the detected temperature from the infrared camera and the surface temperature of porous materials. Backward scattering weakens the effect of background radiation, which brings smaller error at high temperatures and larger error at low temperatures. The measurement error increases rapidly with a high porosity (higher than 0.93). The parameters with measurement error less than 2% are as follows: the porous layer thickness is 14-27 mm, the material emissivity is 0.33-0.81, the porosity is 0.86-0.93 and the pore diameter is 1.5-2.8 mm.