炼铁伴生能源联合循环系统热力学性能分析

Thermodynamic performance analysis of associated energy combined cycle system in ironmaking process

针对富余煤气和烧结余热分散回收利用效果不显著的问题,提出一种炼铁伴生能源联合循环发电方法.通过系统整合,即将烧结余热引入余热锅炉,与传统的富余煤气燃气-蒸汽联合循环系统耦合,构成炼铁工序伴生能源联合循环系统,使炼铁工序中伴生的富余煤气和烧结余热资源梯级利用.基于能量平衡、平衡和能级平衡理论,对系统整合前后热力学性能进行分析比对.绘制出整合前后系统的能流图和流图,并计算出系统中各个组件的能损失和损失.结果表明:在富余煤气初参数和蒸汽侧热力参数均相同条件下,整合后系统能效率及效率分别较整合前提高了1.51%和0.64%,而能级差降低了11.8%.

Aiming at the issue that separated recovery-and-utilization effect for surplus gas and sintering waste heat was not significant,a power generation method of associated energy combined cycle system in ironmaking process（AECCSIP） was proposed.Sintering waste heat was transported into heat recovery steam generator,and coupled with the traditional surplus-gas gas-steam combined cycle system by means of system integration,which formed the（AECCSIP） and cascade utilized the associated resources of surplus gas and sintering waste heat in ironmaking process.Based on the theory of energy,exergy and energy level balances,thermodynamic performances of the systems before and after integration were analyzed.The energy flow and exergy flow diagrams corresponding to the systems before and after integration were drawn and the energy loss and exergy destruction of each component were calculated.Results show that under the same conditions of initial parameters of surplus gas and thermodynamic parameters on steam side,energy and exergy efficiencies of the system after integration improve by 1.51% and 0.64%,respectively,than that of the system before integration,and energy difference decreases by 11.8%.