【作者】 魏清；

【导师】 翟融融；

【作者基本信息】 华北电力大学(北京) ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 目前,人类在生产活动中大量使用化石燃料,排放大量CO2,造成全球气温上升。基于乙醇胺的二氧化碳吸收是多年来商业化的最成功的燃烧后碳捕集技术。醇胺溶液再生需要的热量源自燃煤机组的抽汽,这会减少用于做功的蒸汽量,降低输出功率,增加发电成本。此外,碳捕集流程中有冷凝冷却装置,会消耗大量冷却水。降低碳捕集热耗,提升机组热效率并减少水耗是当前研究的重点内容。针对醇胺吸收法再生能耗高的问题,本文基于膜冷凝器对烟气中低品位热的回收潜力,提出一种耦合膜冷凝器的碳捕集系统,并用Aspen模拟建模。在采用膜冷凝器回收烟气水热后,相比常规碳捕集系统4.341MJ/kg CO2的再生能耗,新系统再生能耗降低到4.275MJ/kg CO2。改变新系统的水热回收参数发现:膜冷凝器烟气水回收率增加,再生能耗降低;膜冷凝器入口烟温增加,再生能耗降低。此外,冷负荷随水回收率的增大而减小,随入口烟温的增大而增大。针对燃煤机组燃烧后脱碳能耗高且冷却水需求大的问题,提出了一种新型集成方案,并用Ebsilon模拟建模。将改进后的碳捕集系统与机组的集成方式由简单集成变为新型集成后,脱碳机组汽轮机输出功由510.719MW增至593.850MW,热效率增加6%,（火用）效率增加5.85%,节约冷却水量为由0增至1497.12kg/s。改变新型集成方案下的水热回收参数发现:膜冷凝器烟气水回收率增加,汽轮机输出功增加;膜冷凝器入口烟温增加,汽轮机输出功增加。节约水量随烟气水回收率增大而减小,随入口烟温增大而增大。更多还原

【Abstract】 At present,human production activities in the use of fossil fuels,a large amount of CO2 emissions,causing global temperature rise.Ethanolamine-based carbon dioxide capture is the most successful post-combustion carbon capture technology commercialized for many years.The heat needed for the regeneration of alcoholamine solution comes from the extraction of steam from coal-fired units,which reduces the amount of steam used for work,reduces the output power and increases the cost of power generation.In addition,there are condensation cooling devices in the carbon capture process,which will consume a lot of cooling water.Reducing the heat consumption of carbon capture,improving the thermal efficiency of unit and reducing the water consumption are the key contents of current research.To solve the problem of high energy consumption in the regeneration of alcoholamine absorption method,this paper proposed a carbon capture system coupled with membrane condenser based on the potential of low grade heat recovery from flue gas by membrane condenser,and modeled it with Aspen.After using membrane condenser to recover flue gas water heat,the regeneration energy consumption of the new system is reduced to 4.275MJ/kg CO2 compared with 4.341 MJ/kg CO2 of the conventional carbon capture system.By changing the water and heat recovery parameters of the new system,it is found that the recovery rate of flue gas water of membrane condenser increases and the regeneration energy consumption decreases.As the inlet flue gas temperature of membrane condenser increases,the regeneration energy consumption decreases.In addition,the cooling load decreases with the increase of water recovery rate and increases with the increase of inlet flue gas temperature.Aiming at the problem of high energy consumption and high demand for cooling water for post-combustion decarbonization of coal-fired units,a new integrated scheme was proposed and modeled by Ebsilon.After the integration mode between the improved carbon capture system and the unit changed from simple integration to new integration,the net output power of the desarburization unit increased from 510.719MW to 593.850MW,thermal efficiency increased by 6%,exergic efficiency increased by 5.85%,and cooling water saving increased from 0 to 1497.12kg/s.By changing the water and heat recovery parameters of the new integrated scheme,it is found that the recovery rate of gas water of membrane condenser increases,and the output power of steam turbine increases.As the inlet flue gas temperature of membrane condenser increases,the output power of steam turbine increases.The water saving decreases with the increase of flue gas water recovery rate and increases with the increase of inlet flue gas temperature.更多还原