煤电“三改联动”技术综述及讨论

Overview and discussion of coal power"Three Reforms and Linkage"technology

“三改联动”是促进煤电清洁低碳发展的重要技术路线。节能降碳改造主要以300/600 MW等级亚临界及超临界、高煤耗的老旧机组为主,采用升参数综合改造方案可以有效降低供电煤耗,同时提高机组灵活性。下一步“降碳”方向是锅炉的生物质掺烧。煤电机组是当前及未来一段时间适合我国国情的主要灵活性资源。煤电机组灵活性改造要解决锅炉低负荷稳燃、水冷壁水动力安全及受热面局部超温、SCR入口烟温低等问题,汽轮机的高温承压部件热应力问题,热控系统的自动调节回路在深调负荷下投运正常问题。分析认为,通过大规模热储能装置协同煤电机组调峰,是未来一个重要发展方向。本文从供汽能力、经济性、可靠性方面,深入研究了煤电机组以主蒸汽、冷再、热再作为主要汽源的工业供汽方案,认为基于中联门参调的热再抽汽方案是宽负荷条件下工业供汽改造的优选技术方案。为了进一步提高热电联产机组供热能力,低压缸微出力方案投资少、节能效果好、运行灵活,是优先选择的方案。“三改联动”深入推进,需要能源体制革命的推动和支撑,要完善适应新型电力系统配套的电力市场体系,充分体现市场化运作机制,提高煤电企业改造的积极性、主动性。

"Three Reforms and Linkage"is an important technical route to promote the clean and low-carbon development of coal-fired power.The carbon reduction reform mainly focuses on 300/600 MW subcritical and supercritical old units with high coal consumption,and adopting the comprehensive reform scheme with upgraded parameters can effectively reduce the coal consumption of the power supply and at the same time improve the flexibility of the units.The next direction for"carbon reduction"is biomass blending in boilers.Coal power units are the main flexibility resources suitable for China’s national conditions at present and in the future.The flexibility reform of coal power needs to solve problems such as boiler low-load stable combustion,hydrodynamic safety and local overheating of the heating surface,low SCR inlet flue gas temperature,etc.,the thermal stress of the high-temperature pressurized components of the turbine,and normal operation of the automatic control of the thermal control system under deep load regulation.It is believed that collaborating with coalfired power units for peak shaving through large-scale thermal energy storage devices is an important development direction in the future.From the aspects of steam supply capacity,economy,and reliability,an in-depth study was conducted on the industrial steam supply scheme of coal-fired power units with main steam,cold reheated steam,and hot reheated steam as the main steam sources.It is considered that the hot reheated extraction scheme based on medium-pressure combined valve participation is the optimal technical scheme for industrial steam supply reform under wide load conditions.In order to further improve the heating capacity of CHP units,the low-pressure cylinder micro-output scheme has the advantages of low investment,good energy-saving effect,and flexible operation,making it a priority choice.The implementation of the"Three Reforms Linkage"requires the promotion and support of the energy system revolution.It is necessary to improve the power market system to adapt to the new power system,fully reflect the market-based operation mechanism,and improve the enthusiasm and initiative of enterprises in their transformation.