Abstract: Based on the T-H diagram, the gradual optimization integration strategy for a large-scale complex process was proposed.By drawing the T-H diagram of the process, the bottlenecks and unreasonable heat transfer processes were analyzed.Through improving the process, introducing the turbine and heat pump of the system, the hot and cold streams were increased or changed, and the T-H diagram was changed accordingly.Repeating the above steps, two approximate parallel hot and cold stream curves were constructed.Energy was reasonably used, and the consumption of utilities was significantly reduced.In this strategy, energy utilization procedure and conversion procedure were comprehensively considered.By applying this strategy to a methanol to olefins plant, the energy integration of the plant was optimized.The results showed that this strategy was effective and convenient.

Key words: T-H diagram, energy integration, process improvement, turbine, heat pump, gradual optimization

摘要： 针对大规模复杂过程的能量利用提出了基于T-H图的逐步优化的综合策略。该策略以系统冷、热物流的T-H图为基础,分析系统能量集成的瓶颈和不合理的换热过程,指导系统引入热机、热泵,或进行工艺改进,从而增加或改变冷热物流,使T-H图发生改变。如此重复,通过多次改进,逐步调整冷、热物流在T-H图上的相对位置,构造出两条近似平行的冷、热物流曲线,使系统能量得到梯次合理的利用,从而达到最大限度降低系统公用工程消耗量的目的。该策略综合考虑了能量利用、转换环节的改进以及公用工程和工艺过程的有机结合,能够实现全过程能量利用的综合优化。应用这种策略,对甲醇制烯烃的能量利用系统进行了优化设计,结果表明所提策略是有效且简便易行的。

关键词: T-H图, 能量综合, 工艺改进, 热机, 热泵, 逐步优化