Temperature and Concentration Fields Monitoring in a Furnace Based on Acoustical Relaxation Model

Monitoring the temperature and concentration distribution in a furnace accurately plays an important role in the efficiency and safety of the combustion. Based on relaxation attenuation model, an acoustical method is proposed to simultaneously reconstruct temperature and concentration fields in the cross section of a furnace. In our work, we first investigate the relaxation attenuation mechanism in a high temperature condition, then the dependence of the sound speed and acoustic attenuation on temperature and concentration is researched. The relations between acoustic parameters and physical parameters are expressed through two coupling models. Then, based on the idea of tomography, temperature field and concentration field are reconstructed simultaneously. Numerical simulations are carried out to verify the feasibility and possibility of the proposed approach, and the results show that the method introduced can simultaneously reconstruct the temperature and concentration fields theoretically, and also it may provide a novel technique in combustion state detection.