优化提纯回用设置的氢网络集成图示法

发布时间：2018-09-05 19:01

【摘要】：近年来,由于炼厂原油加工量和加工深度的不断增加,致使氢气的消耗量急剧增加,由此导致的氢气资源严重匮乏对炼厂发展的制约越来越严重。氢气的高效利用对于炼厂降低成本,节能减排,具有非常重大的现实意义。氢网络集成技术是节约炼厂氢气资源的有效手段,因而是近些年来工业界和学术界研究关注的热点问题。基于夹点分析的概念法是一种非常先进且研究较多的氢网络集成方法,其主要采用图示求解。然而,目前的概念法研究尚有许多不足之处,主要表现为可最大化直接回用,却没有最大化提纯回用。所以,尽管提纯回用包含在内,能在一定程度下节约新氢,但因大多数的研究都将提纯出口产品当做固定浓度的氢源看待,没有将提纯过程当做氢网络集成的一部分进行优化,因而存在进一步提升网络节氢潜力的空间。同时,对于多杂质氢网络,现有的方法所确定的新氢消耗目标值与实际可达到的最小值相比偏离较大,不能有效的回用氢源,同时也不能够设计相应的匹配网络。针对以上不足,本文的研究主要有以下四个方面:(1)提纯过程的图示化表达—质量三角形规则;(2)单杂质氢网络在固定提纯产品浓度和优化提纯浓度两种情况下确定目标值的图示法;(3)多杂质氢网络同时求解目标值和设计匹配网络的图示法;(4)考虑提纯回用的多杂质氢网络目标值求解和网络设计的图示法。本文提出提纯过程的质量三角形规则。通过对提纯过程的物料守恒分析,将其数学关系图示化为三角形规则,并推广为多边形规则,实现图示确定提纯进料,产品和尾气之间的浓度与流量关系。对单杂质氢网络,将提纯过程的质量三角形规则与源阱复合曲线耦合,并通过图示法求解单杂质氢网络优化提纯过程时的最小新氢消耗。在指定提纯产品浓度的情况下,通过移动氢源复合曲线,调整辅助提纯产品线和提纯产品线的流量直至两者相等,即可确定最小新氢和燃气排放目标值。在优化提纯产品浓度的情况下,通过引入最大剩余氢和质量转化三角形,以及对提纯产品浓度和流量的变化调整和氢源复合曲线的移动,来确定氢网络的最小新氢消耗。结果显示,考虑提纯过程优化的单杂质氢网络的最小新氢消耗取决于提纯技术的分离能力。对多杂质氢网络,本文提出能同时求解目标值和设计匹配网络的图示法。通过将单杂质物质回用网络的最邻近匹配算法发展到多杂质氢网络,提出多杂质氢网络的源阱排序规则,对源阱进行排序,并在杂质负荷—流量图中构造源阱复合曲线组。然后,通过源阱匹配的质量三角形规则对氢阱逐个进行匹配设计以得到最小新氢目标值和相应的匹配网络。最后,通过单杂质氢网络的提纯回用优化与多杂质氢网络目标值求解和网络设计相结合,对考虑提纯回用的多杂质氢网络进行目标值求解和网络设计。对于本文所提出的图示研究方法,通过案例分析将结果与已有方法所得的结果进行对比,可得出本文的方法在节约新氢消耗以及目标值求解和网络设计同步性方面的优势。本文的研究丰富和提升了考虑提纯过程优化的氢网络集成研究的夹点图示方法,用以确定最小新氢目标值并设计氢网络。研究成果不仅适用于氢网络,对相应的考虑过程源升级回用的其它网络集成优化的研究也有借鉴意义。
[Abstract]:In recent years, the consumption of hydrogen has increased dramatically due to the increasing processing capacity and depth of crude oil in refineries, resulting in a serious shortage of hydrogen resources, which restricts the development of refineries more and more seriously. The concept method based on pinch analysis is a very advanced and well-studied method for hydrogen network integration, which is mainly solved by graphics. However, there are still many shortcomings in the current conceptual method, the main table. So, although purification and reuse are included, new hydrogen can be saved to a certain extent, because most studies treat purified export products as a fixed concentration of hydrogen source, the purification process is not optimized as part of the hydrogen network integration, so there is an improvement. At the same time, for the multi-impurity hydrogen network, the target value of new hydrogen consumption determined by the existing methods deviates greatly from the actual minimum value, and can not effectively reuse the hydrogen source, but also can not design the corresponding matching network. Aspects: (1) Graphical expression of purification process-mass triangle rule; (2) Graphical method for determining the target value of single impurity hydrogen network under two conditions of fixed purifying product concentration and optimized purifying concentration; (3) Graphical method for solving the target value and designing matching network simultaneously by multi-impurity hydrogen network; (4) Graphical method for designing matching network considering purification and reuse of multi-impurity hydrogen network A mass triangle rule for the purification process is presented. By analyzing the conservation of materials in the purification process, the mathematical relationship is shown as a triangle rule, which is extended to a polygon rule. The relationship between the concentration and the flow rate of the purified feed, product and tail gas is determined by the diagram. The network couples the mass triangle rule of the purification process with the source-well compound curve, and solves the minimum new hydrogen consumption of the single impurity hydrogen network optimization purification process by graphic method. The minimum new hydrogen consumption of the hydrogen network can be determined by introducing the maximum residual hydrogen and mass transformation triangle, adjusting the concentration and flow of the purified product and shifting the hydrogen source compound curve under the condition of optimizing the purified product concentration. The minimal new hydrogen consumption of the optimized single-impurity hydrogen network depends on the separation capability of the purification technology.For the multi-impurity hydrogen network, this paper presents a graphical method which can simultaneously solve the objective value and design the matching network.By developing the nearest neighbor matching algorithm of the single-impurity hydrogen reuse network to the multi-impurity hydrogen network, the source-well of the multi-impurity hydrogen network is proposed. Source-well combination curves are constructed in the impurity load-flow diagram. Then, the matching design of the hydrogen wells is carried out one by one according to the mass triangle rule of source-well matching to obtain the minimum new hydrogen target value and the corresponding matching network. Finally, the optimization of purification and reuse of the single impurity hydrogen network is carried out. The objective value of hydrogen network is solved and the network is designed by combining the objective value of hydrogen network with the network design. For the graphical research method proposed in this paper, the results are compared with the results obtained by the existing methods through case analysis. It is concluded that the method in this paper can save the consumption of new hydrogen and the objectives. This paper enriches and improves the pinch diagram method of hydrogen network integration research considering purification process optimization to determine the minimum new hydrogen target value and design hydrogen network. The study of optimization can also be used for reference.
【学位授予单位】：西安交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TE683

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