Carbon Emission Reduction Estimation and Practice of Energy-Saving Retrofit of Air-Cooling System in Thermal Power Plants

Abstract

To address the critical challenge of balancing thermal power generation efficiency and low-carbon transition, this study develops a multi-dimensional hybrid carbon emission reduction estimation model (LCA-IB Method) that integrates Life Cycle Assessment (LCA) with an Improved Baseline Method. This model innovatively quantifies the carbon reduction contribution rates of individual retrofit technologies while accounting for embodied carbon in equipment and operational carbon emissions. Taking Suizhong Power Plant’s 2×800MW Russian-made thermal power units as a case study, the model was validated using 18 months of high-frequency (5-minute interval) operational data (1.2 million data points) and on-site continuous emissions monitoring system (CEMS) data. Key results show: (1) The retrofit, incorporating spray cooling, counterflow/parallel flow switching, and intelligent control technologies, achieved an annual carbon emission reduction of 192,300 tCO₂, with a 15.4% reduction in unit power generation carbon emissions (from 0.356 tCO₂/MWh to 0.302 tCO₂/MWh). The model’s prediction error was verified to be <2.9%, meeting ISO 14064’s precision requirements. (2) Technical contribution quantification revealed spray cooling (42% contribution, 80,766 tCO₂/year reduction) and counterflow/parallel flow switching (38% contribution, 73,074 tCO₂/year reduction) as core carbon reduction drivers. Spray cooling reduced summer air-cooling tower inlet temperature by 4.8±0.5℃, lowering unit coal consumption by 12.6 g/kWh; counterflow/parallel flow switching optimized cooling efficiency by 18.3% under 75% load. (3) Policy compatibility analysis with the U.S. Inflation Reduction Act (IRA) demonstrated the technology qualifies for dual subsidies: an annual carbon reduction subsidy of (6.73 million (based on 35/tCO₂) and a 30% Investment Tax Credit (ITC) for retrofit investments. In the U.S. market, the technology achieves a 4.2-year payback period, outperforming domestic U.S. retrofit solutions (average 5.8-year payback). This study provides a standardized, high-precision carbon accounting framework for thermal power air-cooling system retrofits and offers a technical-economic roadmap for global thermal power plants to achieve cost-effective low-carbon transitions.