Parametrical study on spectral radiation characteristics of solid fuel combustion medium for energy cascade utilization

Abstract

From the perspective of cascade utilization of photo-thermal energy, this study investigated the effects of parameter variables including pressure, temperature, particle size and number density, and unburned ratio on the spectral radiation characteristics of solid fuel combustion. By coupling the radiative transfer equation with the accurate band model of gas radiation and the Mie theory of particle radiation, the radiation energy characteristics of the one-dimensional (1-D) combustion case were calculated parametrically. Results showed that temperature is the dominant factor. The spectral radiation proportion in the waveband of 0–2 μm accounts for 36.21 % at Ta = 1600 K. Increased pressure and particle number density enhance total radiation. The pressure mainly affects the wavebands of 0–2 μm and 3–4 μm, reaching saturation at 5 bar. Excessive particle number density hinders radiation transfer to the wall. Larger particle sizes increase the spectral radiation proportion of the short waveband. The increased unburned ratio also enhances radiation, but the promotion effect is limited. Optimization of combustion parameters plays a key role in regulating spectral radiation distribution and realizing cascade utilization of photo-thermal energy. This study provides guidance for the energy utilization of solid fuel combustion and the development of carbon neutrality technology.