【作者】 王猛；

【导师】 王晓静； 王之顺；

【作者基本信息】 天津大学 ， 化学工程， 2020， 硕士

【摘要】 我国大量的火电、工业和热力等行业的燃煤锅炉基本上采用的都是湿法脱硫,但是排放烟气会有白烟羽现象,经过研究,白烟羽中含有的颗粒物是导致雾霾的原因之一。近年来,随着国内关于环保和能源的要求日益严格,各省份要求对燃煤锅炉造成的白烟羽进行治理,并对余热和水分进行回收,所以烟气脱白技术是当前解决雾霾问题的主要措施之一。1.本文通过查阅文献,研究了燃煤电厂白烟羽产生和消除的机理,结合机械式和吸收式热泵方法,采用烟气冷凝再热技术。根据湿空气饱和湿含量图和机械式热泵除湿脱白系统模拟,得到烟气冷凝温度为25℃时,除湿脱白效果较好,除水率达到80%以上。2.对于NH₃-H₂O吸收式热泵烟气除湿脱白系统,对发生器的塔板和进料位置优化后,随着发生温度的升高,烟气冷凝温度降低,COP先升高在降低,当塔底温度在118℃以上,即烟气冷凝温度在35℃以下,COP处于较高水平,在0.678左右。对于H₂O-Li Br吸收式热泵烟气除湿脱白系统,随着发生温度的升高,烟气冷凝温度降低,COP逐渐降低,当发生温度在85-88℃时,COP较高,当烟气冷凝温度在42℃,系统cop达到了1.29;随着发生器进口浓度的升高,烟气冷凝温度升高,COP逐渐升高,当发生器进口质量浓度在57%以上时,即烟气冷凝温度在40℃以上,COP最高可达到1.68。3.对三种烟气除湿脱白系统性能对比分析,机械式热泵烟气除湿脱白系统的COP高,吸收式热泵烟气除湿脱白系统的烟气余热回收效果好,虽然机械式烟气除湿脱白系统的冷凝回收水量最多,但需向脱硫塔补水,吸收式热泵烟气除湿脱白系统在回收水量同时,基本可以做到无补水,以10t/h的燃煤锅炉为例,年回收水量可达到1.21万吨,锅炉热效率理论提升7.4%。更多还原

【Abstract】 A large number of coal-fired boilers in Chinese thermal power,industrial and thermal industries basically use wet desulfurization,but the emission of flue gas will cause white mist,After research,the particulate matter contained in the white mist is one of the causes of smog.In recent years,with the increasingly strict domestic requirements on environmental protection and energy,Provinces require the treatment of white mist from coal-fired boilers,and the recovery of waste heat and water.Therefore,“Flue gas dewhitening”technology is one of the main measures to solve the problem of smog.1.By referring to the literature,this paper studies and analyzes the mechanism of the generation and elimination of white mist in coal-fired power plants.Combining the mechanical and absorption heat pump methods,the flue gas condensation reheat technology is used.According to the humid air saturation moisture content map and the mechanical heat pump dehumidification and de-whitening system simulation,it is obtained that when the flue gas condensation temperature is 25℃,dehumidification and de-whitening effect is the best,and the dehydration rate reaches more than 80%.2.For the NH₃-H₂O absorption heat pump flue gas dehumidification and dewhitening system,after the optimization of the generator tray and feed position,as the temperature rises,the flue gas condensation temperature decreases,COP first rises and falls,When the tower bottom temperature is above 118°C,that is,the flue gas condensation temperature is below 35°C,the COP is at a relatively high level,around0.678.For the H₂O-Li Br absorption heat pump flue gas dehumidification and dewhitening system,as the temperature rises,the flue gas condensation temperature decreases and the COP gradually decreases.When the occurrence temperature is85-88℃,the COP is higher,when the flue gas condensation temperature is 42℃,the system cop reaches 1.29;With the increase of the inlet concentration of the generator,the flue gas condensation temperature increases,and the COP gradually increases.When the inlet mass concentration of the generator is above 57%,that is,the flue gas condensation temperature is above 40°C,the maximum COP can reach 1.68.3.Comparative analysis of the performance of the three flue gas dehumidification and dewhitening systems,The mechanical heat pump flue gas dehumidification and dewhitening system has a high COP,and the absorption heat pump flue gas dehumidification and whitening system has a good waste heat recovery effect.Although the mechanical flue gas dehumidification and whitening system has the most condensed water recovery,it needs to be sent to the desulfurization tower Hydration.Absorption heat pump flue gas dehumidification and de-whitening system can basically achieve no water replenishment while recovering the amount of water.Taking a 10t/h coal-fired boiler as an example,the annual water recovery can reach121,000 tons,and the theoretical thermal efficiency of the boiler is increased by 7.4%.更多还原