Key Takeaways & Executive Findings
- •• • Boiler combustion optimization using support vector machines and neural networks improves boiler thermal efficiency and reduces NOx emissions, directly lowering operational costs and environmental compliance burden. • • Turbine flow path upgrades, including full three-dimensional CFD optimization, new high-efficiency blades, and combined steam seals, significantly increase cylinder efficiency and reduce heat rate, leading to measurable fuel savings. • • Installation of low-temperature economizers reduces unit coal consumption and decreases energy and water consumption in dust removal and desulfurization systems, yielding both economic and environmental benefits. • • Data-driven predictive maintenance and real-time performance optimization of condensers achieve nearly 50% energy savings in circulating water pumps and an average reduction in coal consumption rate of 2-3 g/(kW·h), demonstrating substantial operational efficiency gains.
Abstract
Thermal power units have long dominated China's energy structure due to the low cost of coal and their role in ensuring grid stability. However, under the dual pressures of climate change and national carbon peaking/neutrality goals, the environmental impact of their 'three wastes' has become critical, necessitating energy-saving retrofits. This review systematically examines mainstream energy-saving technologies for thermal power units, including boiler combustion optimization, heating surface cleaning, turbine flow path upgrades, waste heat recovery and cascade utilization, and cold-end system optimization. Using coal consumption rate as the core economic index, the study integrates case studies and operational data from typical domestic and international units to evaluate the latest progress, practical effects, advantages, and limitations of each technology. Results indicate that these technologies significantly improve energy efficiency and reduce pollution. For instance, boiler combustion optimization based on support vector machines and neural networks enhances thermal efficiency and reduces NOx emissions. Turbine flow path modifications, from full three-dimensional CFD optimization to advanced blades and combined steam seals, yield notable gains in cylinder efficiency and heat rate reduction. Low-temperature economizers reduce coal consumption and auxiliary power/water use in dust removal and desulfurization systems. Heat pump applications include absorption, compression, and hybrid types. In cold-end optimization, data-driven predictive maintenance and real-time performance tuning of condensers achieve nearly 50% energy savings in circulating water pumps and an average coal consumption reduction of 2-3 g/(kW·h). Despite these advances, gaps remain in multi-objective optimization robustness, intelligent diagnosis, and advanced materials. Future research should focus on deep reinforcement learning for adaptive control, sensor networks for real-time diagnostics and predictive maintenance, and high-temperature corrosion-resistant materials for heat exchangers, while balancing initial investment and maintenance costs.
1. Introduction
The thermal power sector remains the backbone of China's electricity supply, yet its environmental footprint has become untenable under stringent carbon reduction mandates. Existing energy-saving research has largely been siloed, focusing on isolated technologies or specific scenarios, which hampers the integrated deployment of solutions across the plant. This fragmentation has stalled the large-scale adoption of cost-effective retrofits, as operators lack a holistic framework to prioritize investments based on measurable economic and environmental returns.
This review addresses that bottleneck by systematically categorizing and evaluating mainstream energy-saving technologies—from boiler combustion optimization to cold-end system upgrades—using coal consumption rate as a unifying economic metric. By synthesizing recent case studies and operational data, we provide a comparative analysis of each technology's practical benefits and limitations, enabling plant operators and policymakers to make informed decisions. The findings underscore the potential for integrated retrofits to achieve significant efficiency gains, while also identifying critical research gaps—such as model robustness and material durability—that must be overcome to fully realize the sustainable development of thermal power units.
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Tao JING, Quanjie LI, Xiannan DU, Naimu YANG, Zhenshuai YANG, Sizheng TONG, Bing LI, Ye FAN, Jinwen SHI (2026). A Review on Energy-Saving and Consumption-Reducing Technologies for Thermal Power Units Based on Economic Benefit Evaluation. The Chinese Journal of Process Engineering. https://doi.org/10.12034/j.issn.1009-606X.225184
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Frequently Asked Questions
What are the primary failure mechanisms or limitations of current boiler combustion optimization models based on neural networks and support vector machines?
Current models often suffer from insufficient robustness and poor real-time performance, particularly under fluctuating coal quality and load conditions. They rely on large amounts of labeled data, which may not be readily available, and can fail to generalize to unseen operating scenarios. This limits their practical deployment for continuous online optimization.
How does the integration of advanced sensors and DAS steam seals contribute to reducing leakage rates in turbine systems, and what quantitative improvements have been observed?
Advanced sensor networks enable real-time monitoring of flow path component wear, allowing for proactive adjustments. Combined with DAS (Dynamic Adaptive Seal) active compensation, leakage rates can be further reduced. While specific leakage reduction percentages are not detailed in the text, the approach supports maintaining optimal economic conditions during coal quality fluctuations and load changes, thereby reducing non-stop risks and maintenance costs.
What are the cost implications and scalability challenges of using high-temperature, corrosion-resistant materials in low-temperature economizers and condensers?
The initial investment and maintenance costs for advanced materials are significant, and their long-term durability under extreme conditions requires further evaluation. Scalability is challenged by the need to balance material performance with cost-effectiveness across different boiler types and sizes. Future research aims to enhance durability and develop cost-benefit solutions for widespread adoption.
Can you provide specific data on the energy savings achieved by cold-end system optimization, particularly regarding circulating water pump energy consumption and coal consumption rate?
Data-driven predictive maintenance and real-time performance optimization of condensers have achieved nearly 50% energy savings in circulating water pumps. Additionally, these measures lead to an average reduction in coal consumption rate of 2-3 g/(kW·h), which translates to substantial fuel savings and emission reductions for a typical unit.
What are the comparative advantages and limitations of absorption, compression, and hybrid heat pump systems in waste heat recovery for thermal power units?
The text indicates that heat pump applications include absorption, compression, and hybrid types, but does not provide a detailed comparative analysis. Generally, absorption heat pumps are advantageous for low-grade heat recovery but have lower COP, while compression heat pumps offer higher efficiency but require electricity input. Hybrid systems aim to combine benefits. The choice depends on specific site conditions, heat source temperature, and economic factors.
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