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.

总结了2017-2018年、2018-2019年两个取暖季,北方地区冬季清洁取暖工作所取得的进展,分析了目前清洁取暖存在的主要问题.北方地区冬季清洁取暖总体进展顺利、成效显著.截至2019年取暖季结束,北方地区冬季清洁取暖率达到50.7％,相比2016年提高12.5个百分点.但清洁取暖工作还存在成本较高、技术路线选择不当、农村地区推进难度大、可持续性差、补贴压力大等问题.针对这些问题,从完善补贴政策、扩大补贴范围、加大农村清洁取暖支持力度、建立长效机制等方面提出了建议,为推进清洁取暖工作的可持续发展提供参考.

通过论述2017—2019年两个取暖季以来北方农村地区冬季清洁取暖工作所取得的进展,从运行成本、污染物排放量、单位投资环境效益等3个方面对比分析了农村地区4种主要清洁取暖技术路线——燃气壁挂炉、直热式电暖器、空气源热泵热风机、生物质+专用炉具,得出结论:从运行成本来看,生物质+专用炉具每取暖季运行成本最低,其次是空气源热泵热风机、燃气壁挂炉,直热式电暖器成本最高;从每取暖季每户污染物排放总量来看,排放量从小到大依次为空气源热泵热风机、燃气壁挂炉、直热式电暖器和生物质+专用炉具;从万元投资总减排量来看,采用生物质+专用炉具效益最高,其次是燃气壁挂炉、空气源热泵热风机、直热式电暖器.最后,对进一步推动农村清洁取暖工作提出了建议.

系统地论述了大型燃气-蒸汽联合循环电厂的关键设备选择、关键系统设计和主厂房布置原则,对大型燃气-蒸汽联合循环电厂的性能优化、出力和效率等技术指标进行了分析,同时还进行了造价及电价分析.

Based on the feasibility analysis of service power plant heating system retroffiting, the authors believe that heating system retroffiting of power plants with 125 MW or higher condensed steam units are technically feasible. It is able to fully utilize available, power resources, replacing old and small thermal power plants, centralized boiler rooms, and scattered small boilers, resulting in more efficient energy usage and maevostructue rogulation. In the mean time, schemes and recommendations are presented for future implementation.

The authors introduce new thermal power technologies briefly in China for recent years,including the supercritical and ultra supercritical units,large-sized CFB technology,IGCC clean-coal generation,biomass power generation,large-sized air-cooling generation and SCR technologies.