混合烷烃脱氢产物分离单元的换热网络优化

摘要

以某25万t/a的混合烷烃脱氢装置为背景,选取其中产物分离单元,采用Aspen Plus软件对其进行了流程模拟,模拟结果与现场数据吻合良好.在此基础上,利用夹点技术对现行工况的换热网络进行了夹点分析,在最小换热温差10℃条件下,现行换热网络冷热公用工程的节能潜力分别可达11.61%和8.88%;优化脱乙烷塔进料温度后,节能潜力可分别提高至12.48%和9.60%.通过计算机模拟发现现行换热网络存在着跨越夹点换热器.提出了换热网络优化设计方案,优化换热网络相比于原换热网络冷热公用工程消耗量分别降低12.21%和9.39%.%The product separation unit in a 250 kt/a C3-C4 paraffin''s dehydrogenation device was modeled with the Aspen Plus.The results show good coincidence with the site data.After extracting data from the model, pinch analysis was applied to the existing heat exchanger network (HEN) with a minimum heat transfer temperature difference of 10 ℃ and the potential of energy saving was obtained which were 11.61% and 8.88% for the cold and hot utilities respectively.Furthermore, the deethanizer column′s feed temperature was optimized so that the energy saving potential of cold and hot utilities increased to 12.48% and 9.60%.Heat exchangers across the pinch have been found through computer simulation.A practical HEN was proposed which might save the consumption of cold and hot utilities up to 12.21% and 9.32%.