工艺装置在回收产品等热物流的热量预热进料或其他冷工艺物流中,利用夹点之下的热量适当增产蒸汽,提高装置能量回收效率。热进出料作为装置间热集成的重要方法,不仅减少了上下游装置总公用工程消耗量,而且能够通过合理改变上下游装置的夹点位置和总组合曲线趋势,优化装置生产蒸汽的压力等级和流量。基于夹点技术构建涉及热进出料物流的温焓线和工艺装置的总组合曲线,通过反转并平移热进出料物流的温焓线确定最高的热出料温度,同时考虑不同压力等级蒸汽对热量需求的差别优化蒸汽生产参数。提出的工艺装置热进出料及蒸汽平衡优化应用于渣油加氢和催化裂化装置的热进出料优化,结果表明不仅降低了上下游装置总公用工程量,而且提高了工艺装置生产蒸汽的品质,增加了能量回收利用效率。
Heat of hot process streams is recovered to simultaneously below pinch points to increase the preheat cold streams, and some steam is generated efficiency of energy recovery. Hot feed/discharge between plants cannot only reduce the total utilities of up-plant and down-plant, but also increase steam generation by changing the pinch location and shape of grand composite curve (GCC). Composite curve of streams employed for hot feed/discharge and GCC are figured in a T-Q diagram, where the temperature of hot discharge is targeted by reversing and moving the composite curve of streams in horizontal direction, and the pressure and flowrate of steam generation are optimized by considering the energy requirement of steam in different pressure grade. An industrial example involving a vacuum residue hydrotreating plant (VRHP) and a fluid catalytic cracking plant (FCCP) is investigated to demonstrate the performance of presented model. The solution results indicate a decrease in the total utilities and an increase in the steam generation.