将复杂的大型钢铁企业的生产系统分解为相互关联的物质流动和能量流动过程两部分.针对其中的物质流动过程,构造工序物质流图。并建立物质流模型;针对能量流动过程,构造工序能量流图,并建立能量流模型;在分析钢铁企业CO2排放影响因素的基础上,建立了吨钢CO2排放量的计算模型及物质流、能量流对CO2排放的影响模型,分析了钢铁生产过程中各种物质流、能量流的变化对CO2排放的影响;将模型应用于具体企业,通过对比分析,指出了我国钢铁企业CO2减排的努力方向:①增加各生产工序的外加物质流,减少各生产工序的排放物质流和循环物质流;②降低转炉铁钢比;③提高电炉钢比;④提高自发电的比例和发电水平,发展“只买煤、不买电”能源结构模式;⑤加强余热、余能的回收利用水平.
The iron and steel factory is decomposed into two parts: the material flows process and the energy flows process. The material flow diagram is structured, and the material flow model is constructed accordingly. The energy flow diagram is structured, and the energy flow model is constructed based on the diagram. The calculating model for the CO2 emissions per ton steel in a factory is constructed, which consists of a variety of factors that have influences on CO2 emissions. The influences of the materials flows and energy flows on CO2 emissions in the iron and steel-producing process are analyzed. The models are adopted in a factory to discuss the influences, and the results indicate that some measures should be taken to reduce the CO2 emissions in China steel industry: (1)increasing the material flows from outside of a process and reducing the material flows discharged and recycled ; (2)reduclng the hot iron consumption per ton steel in a converter; (3)increasing the output of steel that is produced by electrical furnace; (4)improving the electricity generating inside the factory and developing the energy mode of "buying only coal and no electricity" ; (5)enhancing the recovery of residual heat and energy.