Coal-fired power units typically exhibit strong nonlinearity
long time delays
and pronounced physical couplings during operation. These characteristics make it difficult for traditional mechanismbased or purely data-driven modeling approaches to simultaneously achieve high dynamic accuracy
strong generalization capability
and low deployment cost in real industrial environments. To address these challenges
this study proposes a physics-informed dual-branch convolutional transformer network(PID-CTNet) that integrates physical priors with deep learning to achieve collaborati
ve prediction of multiple combustion-related variables. [Methods
]
First
a multi-source feature space is reconstructed based on combustion and thermodynamic mechanisms. Twenty-seven key physical variables are selected from four categories(load commands
fuel and airgas system parameters
thermodynamic properties of the working fluid
and historical feedback indicators) to form a physically meaningful input representation. Second
a multi-task deep learning framework combining convolutional neural networks(CNN) and Transformer is developed. The front-end temporal convolutional networks(TCN) extract local transient features and perform dimensionality reduction
while the back-end Transformer introduces a self-attention mechanism with a global receptive field to capture long-term dependencies and large-delay characteristics inherent in boiler dynamics. Finally
a hard parameter-sharing strategy is employed to enable simultaneous prediction of NO
x
SO
2
and CO emissions
as well as main and reheat steam temperatures
within a unified modeling framework. [Results
]
Experimental results demonstrate that the proposed end-to-end model achieves high prediction accuracy
with root mean square error of 2.895
mean absolute error of 1.654
mean absolute percentage error of 0.565%
and coefficient of determination R
2
of 0.957 on the test set. The prediction errors of all five industrial key indicators remained below 3%
significantly outperforming traditional regression and time-series models such as SVR and LSTM
as well as single-task deep learning baselines. Ablation studies further validate the effectiveness of incorporating physical priors
the complementary roles of the TCN-Transformer hybrid architecture
and the performance gains brought by the multi-task learning mechanism. These components jointly enhance model accuracy
stability
and robustness under complex operating conditions
including load fluctuations
fuel variations
and frequent operational adjustments. [Conclusion
]
The PID
-CTNet model effectively integrates physical mechanisms with deep learning
achieving a favorable balance between prediction accuracy and computational efficiency. By providing lightweight and reliable collaborative prediction of emissions and steam temperature parameters
the proposed method offers a practical and deployable solution for intelligent operation
emission optimization
and safety control of coal-fired power units. The results demonstrate that physics-informed multi-task learning is a promising direction for improving the interpretability
engineering applicability
and longterm maintainability of data-driven models in modern power plant operation and optimization.