Modelling and application of acoustic temperature measurement in multi-source waste incinerators: Spatial monitoring and characterization for thermal profiles

Multi-source waste co-incineration processes face challenges like inadequate incineration data perception, heterogeneous fuel composition, and fluctuating pollutant emissions, requiring the integration of acoustic temperature measurement (ATM) for spatially resolved characterization to enable smart combustion control. This study developed an ATM framework that incorporates gas composition-adaptive corrections and deploys acoustic sensor arrays to reconstruct real-time 2D thermal profiles in full-scale incinerators. In detail, a modified ATM model was derived, incorporating corrections for gas composition variability, particulate matter (PM), and water vapor effects. Experiments in both simulated and real-scale incineration environments demonstrated high accuracy (errors <5.0 %). Cold-state and hot-state experiments verified the model's sensitivity and stability under diverse conditions, revealing that increased H2O and PM concentrations elevate acoustic wave propagation errors. The proposed model corrects for these influences, achieving average temperature deviations of ±3.8 % in simulated flue gas. Field validations in 650–750 t/d incinerators co-combusting industrial organic solid waste (IOSW) demonstrated <3.3 % temperature deviation, with spatial resolution achieving 0.5–1.2 m granularity to identify localized high-temperature zones (>950 °C). These results establish ATM-driven spatial thermal analytics as a transformative paradigm for next-generation intelligent incineration systems.