【作者】 杨波；

【导师】 杨双平；

【作者基本信息】 西安建筑科技大学 ， 冶金热能工程， 2018， 硕士

【摘要】 我国钢铁企业年均用能约占全国总能耗的15%,烧结矿生产中能耗在钢铁企业总能耗中占比较大,其环冷烟气排放温度较高,具有较好的烟气余热回收潜力,对其烟气余热进行回收再利用不仅可有效降低钢铁生产能耗,还可减弱烟气排放对环境造成的污染。本课题结合山西某钢铁公司烧结厂环冷机烟气排放的实际情况,提出一种利用烧结环冷机烟气余热进行回收发电的方案。首先对烧结矿生产过程中产生的环冷机烟气进行了测试并分析。其次,在调研该钢铁公司烧结厂一年生产过程中的物料收支情况基础上,进行了烧结生产过程中的物料平衡模型及能量平衡模型的建立、分析及研究,且全面评价了烧结环冷机烟气余热回收潜力。再对烧结环冷机烟气发电中的余热锅炉热力建模、分析的基础上,进行烧结环冷机烟气发电双压、单压、闪蒸锅炉系统热力研究、对比和汽轮机热力建模及研究。最后对该发电系统进行经济效益分析、环境效益分析及社会效益分析。通过本课题的研究,得出以下结论:（1）环冷机的烟气成分与空气类似,各成分含量为N₂=77.04%、CO₂=5.83%、H₂O=0.7%、O₂=16.43%;烧结环冷机1、2段烟气余热回收潜力大,环冷机1段烟气流量为170000Nm³/h温度为390℃焓值为532.48kJ/Nm³,环冷机2段烟气流量为130000Nm³/h烟气温度为290℃焓值为391.35kJ/Nm³。（2）烧结生产过程的物料收支基本保持平衡,误差仅为3.2%,物料支出项中的烧结矿占支出物料比例比较大;烧结生产过程的能量收支保持平衡,其中烧结矿携热量占热支出能量比例最大,可达到37.23%,具有较大的余热回收值。（3）烧结环冷机烟气余热发电双压余热锅炉系统较单压、闪蒸余热锅炉系统余热利用率高、?效率高、蒸汽产量多及蒸汽参数要优于这两个系统产生的蒸汽参数。该发电系统余热利用率为56%、发电效率为77%、及年发电量为4456.8万kW*h。（4）烧结环冷机烟气余热发电系统每年可盈利1128.62万元,投入使用3.37年后开始为企业盈利,经济效益好。由环境效益分析表明该发电系统年发电量4456.8万kW*h,每年可节约标煤量14404.38吨,环境效益显著。更多还原

【Abstract】 The annual energy consumption of iron and steel enterprises accounts for about15%of the total energy consumption in China.The energy consumption in sinter process is relatively large in the overall ironmaking&steelmaking industry,among which the utilization potential of sintering ring cooler exhaust gas is high because of its high exhausting temperature.The recovery and reuse of the waste heat from the exhaust gas can not only effectively reduce the energy consumption of steel production,but also can reduce the pollution caused by the emission of flue gas to the environment.In this paper,a scheme to recover the power from the waste heat of the flue gas of sintering ring cooler is put forward based on the actual situation of the flue gas emission from a iron&steel enterprises sintering plant in Shanxi province.Firstly,the flue gas produced from the ring cooler during sintering process is tested and analyzed.Secondly,the material balance model and energy balance in the sintering process were established,analyzed and studied based on the investigation of the material balance data of last year,the potential of the waste heat recovery of the flue gas of the sintering ring refrigerator is also comprehensively evaluated.Thirdly,the thermodynamic research and comparison of dual pressure,single pressure and flash boiler system for flue gas generation of sintering ring cooler were conducted and the steam turbine thermal modeling and research is also carried out on the basis of the thermal modeling and analysis of the waste heat boiler in the flue gas power generation of the sintering ring cooler.Finally,the economic benefit analysis,environmental benefit analysis and social benefit analysis of the power generation system are carried out.The conclusions of this paper are as follows:（1）The composition of the flue gas is similar to the air,and the contents of each component are N₂=77.04%,CO₂=5.83%,H₂O=0.7%and O₂=16.43%,respectively.The recovery potential of the flue gas waste heat of the 1 and 2 sections of the sintering ring cooler is larger,The flow of flue gas in the first section of the ring cooler was 170,000Nm³/h,and the temperature was 390°C,the enthalpy value was 532.48 kJ/Nm³,and the flow rate of the flue gas in the second section of the ring cooler was 130000 Nm³/h,the flue gas temperature was 290°C and the enthalpy value was 391.35 kJ/Nm³.（2）The input and output material of the sintering process is basically balanced with error of 3.2%,the sinter are accounts for a larger proportion of the output material.The input and output energy of the sintering process keeps in balance,the proportion of heat energy consumed by the sintered heat is the largest among them,which can reach37.23%,and its value of waste heat recovery is the largest.（3）The double pressure waste heat boiler system of the waste heat generation of the sintering ring cooler is better than that of the single pressure and flash waste heat boiler system for its higher waste heat utilization rate,higher efficiency,higher steam output and better steam parameters.The waste heat utilization rate of the power generation system is 56%with generation efficiency of 77%,and the annual generating capacity is 44.568 million kW*h.（4）Annual profit of flue gas waste heat generation system of the sintering ring cooler is 11.2862 million yuan.The system will be profitable for the enterprise after the installation and use of the power generation system for about 3.37 years and its economic benefit is good.The annual generation capacity of the power generation system is 44.568 million kW*h and could save 14.40438 thousand tons of standard coal every year with significant environmental benefit.更多还原