中国工程科学 (Apr 2023)
High-Level Layout Technology and Engineering Application for Advanced Air-Cooled Ultra-Supercritical Steam-Turbine Generator Unit
Abstract
Improving the power generation efficiency of coal-fired units is an effective measure to achieve energy conservation and carbon reduction. The engineering application of 700 ℃ ultra-supercritical coal-fired power generation is hindered by the high price of superalloy materials; therefore, it is necessary to explore new layouts and structures to shorten the high-temperature steam pipelines and reduce the engineering costs. By taking the phase III expansion project—the world’s first demonstration project of high-level layout—of the Jinjie coal-fired power plant as an example, this study introduces the engineering innovation practice of the high-level layout technology for an air-cooled ultra-supercritical steam-turbine generator unit. The results indicate that the reinforced concrete frame and shear wall structure can effectively lower the overall center of gravity and improve the seismic performance of the main power house,thereby ensuring the safety of the main power house structure, high-temperature steam pipelines, and steam turbine generator unit through technological breakthroughs. Compared with those of the conventional layout (its operating floor level being 12.6‒17 m), the main steam and reheat steam pipelines of the high-level layout (its operating floor level being 65 m) can save 34.2% and 20.9% of raw materials,respectively; and exhaust steam pipes of the air-cooled island can save 93% of raw materials. Furthermore, the power supply coal consumption can be reduced by 4.5‒5.1 g/(kW·h) compared with the design value, and the overall economical efficiency is significantly improved. The monitoring data after operation show that all parameters in the real-time on-line monitoring system of the main power house structure are within the safety threshold, and the plant structure and critical equipment are both in a safe state. Therefore, we propose to promote clean and efficient coal-fired power generation technologies and apply the high-level layout technology to the advanced air-cooled coal-fired power units in northeast, north, and northwest China as these regions are rich in coal but short of water. This can provide practical experience for the construction of economical high-temperature steam pipelines for 700 ℃ ultra-supercritical coal-fired power units.
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