Coal-fired power plants play a pivotal role in China's power system
and accurate forecasting of their CO
2
emissions is crucial for achieving energy-saving and emission-reduction targets. To address this challenge
this paper proposes a short-term CO
2
emission prediction model for coal-fired power plants based on CNN-BiLSTM-Attention. [Methods
]
First
feature selection is performed by analyzing the correlation between CO
2
emission rates and various input variables
including unit load
SO
2
emission rate
NO
x
emission rate
and environmental factors
thereby reducing redundant information that may impair model training. Specifically
the Pearson correlation is used to quantify the linear relationship between each candidate feature and the CO
2
emission rate
and features with a correlation coefficient below 0.2 are excluded. The raw operational data are then normalized to the range [0
1
]
and segmented into samples using a sliding time window to capture temporal dynamics. Subsequently
the selected features are fed into the proposed CNN-BiLSTM-Attention model. In this hybrid architecture
the CNN layer extracts local patterns from the input sequence
the BiLSTM layer captures both forward and backward temporal dependencies
and the attention mechanism assigns adaptive weights to the most informative time steps. To further enhance performance
an improved Kepler optimization algorithm(IKOA) is introduced to optimize the model's hyperparameters. The model is validated using real-world operational data from coal-fired power plant units. In addition to root mean square error(RMSE)
the mean absolute error(MAE) and the coefficient of determination(R
2
) are also computed to comprehensively evaluate prediction performance. Comparative experiments show that among LSTM
BiLSTM
CNN-BiLSTM
and CNN-BiLSTM-Attention
the last model achieves the lowest RMSE of 24.329 2 t/h
compared to 26.261 0 t/h
26.039 3 t/h
and 25.429 3 t/h for the other three models
respectively. Moreover
when optimizing the CNN-BiLSTM-Attention model with four metaheuristic algorithms(genetic algorithm(GA)
whale optimization algorithm(WOA)
Kepler optimization algorithm(KOA)
and IKOA)
the IKOA yields the best fitness value of 21.584 1 t/h
slightly outperforming WOA(21.594 6 t/h)
KOA(22.136 0 t/h)
and GA(22.807 2 t/h). Results demonstrate that the proposed model exhibits strong transferability across units of similar capacity and effectively captures CO
2
emission trends over time
although prediction errors increase during seasonal transitions due to variations in operating conditions and coal quality.[Results
]
The proposed model consistently outperforms baseline models in both prediction accuracy and stability.[Conclusion
]
The CNN-BiLSTM-Attention model enables effective CO
2
emission forecasting for coalfired power plants even without direct CO
2
measurements
showing significant applicability and potential for broader deployment. This capability is particularly valuable for plants lacking continuous emission monitoring systems(CEMS)
offering a cost-effective alternative for CO
2
estimation. However
long-term or cross-seasonal predictions require further consideration of external factors such as coal quality. This study is primarily validated on limited units from a single plant; thus
its generalizability across different regions
coal sources
and operational strategies warrants further investigation. Future work will incorporate direct coal-quality indicators through multisource data fusion or online updating mechanisms to enhance long-term predictive performance and robustness.