化工过程系统用能评价与优化方法研究进展

介绍了现代化工过程系统中的几种用能评价与优化方法。通过介绍、比较夹点技术和火用分析法原理,提出了两者的适用条件和局限性,由此引入了结合夹点技术和火用分析法优点的能级分析法,详细分析了三者之间的联系及优缺点。同时论述了最新的能量优化方法进展,也是技术改进的发展方向。     

夹点分析法在化工过程全局用能优化的应用

介绍了夹点分析在化工过程全局用能优化中的应用，用夹点分析法在实现各工艺装置内部热量交换的基础上，进行过程全局的剩余热阱和热源与公用工程系统的能量集成，包括余热回收、联产功量、蒸汽系统设计和透平网络综合。应用实例表明，利用该方法可以大幅度实现节能，是现代化工企业节能的发展方向。     

水级联法确定间歇用水过程的夹点及废水最小化

利用水级联分析法对间歇过程用水网络进行研究,确定过程的用水夹点及最小新鲜水用量和最小废水排放量,提出了间歇用水过程的全局夹点的概念,考虑了用水过程的流率限制,在水级联表格中用流率替代了传统水级联分析法中的传质量,识别过程中每个时间段的局部夹点及公用工程目标,通过全局夹点和局部夹点的比较,指出过程的用水瓶颈,设置储罐打破瓶颈,使用水网络公用工程目标最小化。通过实例对水级联分析法进行了详细的阐述,计算结果与文献一致,表明该方法是一种易于理解、直观且简便有效的确定间歇过程用水网络的夹点及最小公用工程的方法。     

大型复杂过程系统用能的诊断与调优

针对大型复杂过程系统用能的诊断与调优，发展了夹点分析（夹点技术）方法。提出采用虚拟温度法，确定各流股匹配换热的传热温差；将过程的夹点分析区分为操作型夹点计算与设计型夹点计算两个层次：操作型夹点计算用于过程用能的诊断；设计型夹点计算指导过程用能的调优。基于以上改进，开发了大型复杂过程系统用能诊断与调优策略，并应用于国内某厂乙烯装置的节能改造，可使该装置吨乙烯能耗降低４．１８７ＧＪ。应用表明本文提出的方法是指导大型复杂过程系统用能诊断与调优的有利工具。     

提纯回用氢网络的夹点变化规律

在氢系统中引入提纯装置可以经济有效地提高氢气的回用率,是氢系统中广泛采用的方法。但引入提纯回用过程可能会影响氢系统的夹点位置,还可能使氢系统出现多夹点。由于夹点对系统性能的分析与优化具有极其重要的作用,而夹点位置的变化则会影响到用氢过程的匹配。在氢夹点技术的基础上,通过图示分析法,研究了在不同提纯产品浓度下提纯回用过程的夹点变化规律和趋势,对于考虑提纯回用的氢网络集成具有重要的意义。     

基于夹点技术的天然气净化装置的用能分析

采用夹点技术对某天然气厂净化装置进行了能量优化分析,找出了系统用能不合理的环节,按照夹点设计原则,以系统最大热回收为目标,通过调节过程流股的温差贡献值对物流进行重新匹配,初步调优后系统可以节能486.569 kW。     

夹点技术在化工设计中的应用

夹点技术是目前化工过程设计中一种全新的，强有力的方法，现已有许多领域得到广泛应用。本文概述了夹点技术的基本原理，介绍了国内外夹点技术在化工过程中设计中的应用现状，并对其应用前景作了展望。     

夹点分析法在换热网络优化中的应用

夹点技术是一种卓有成效的过程能量综合方法，本文介绍了夹点技术的基本思想、及其所遵循的规则。准确地找出换热网络中的夹点，可以有效地进行换热网络的最优设计，最大限度地利用能量。     

受网络夹点控制的装置的改造分析

本文分析了过程夹点和网络夹点的不同,指出了在改造过程中存在网络夹点,并且节能潜力受网络夹点的控制,同时提出了克服网络夹点的途径,即分流和调整换热网络结构。通过对某炼油厂润滑油加氢补充精制装置的分析。提出了不分流时克服网络夹点的方法,即同一温闰的冷流体按热溶流率CP值减小依次被加热;同一温位的热流体按CP值减小依次被冷却。最后,文章对该装置提出了采用“一改动方案”的改造方案,节能效果和经济效益显著。     

夹点技术在换热网络优化中的应用

换热网络的优化设计是石化行业生产过程中经常遇到的问题,夹点技术在换热网络优化中有着重要的地位。本文简要阐述了换热网络的基本思想以及夹点技术在换热网络中的应用,用一个简单例子说明了如何运用问题表格法来确定换热网络的夹点,并介绍了夹点技术存在的局限性。     

Combined Water-Oxygen Pinch Analysis with Mathematical Programming for Wastewater Treatment

Water-oxygen pinch analysis is an effective method to decrease the wastewater quantity and improve the wastewater quality. But when multiple-contaminants are present, the method is difficult to be carried out. In this paper, the method that combines water-oxygen pinch analysis with mathematical programming is proposed. It obtains the general optimal solution and leads to the reuse stream that cannot be found only by pinch analysis. The new method is illustrated by an example, and the annual cost is reduced by 8.43% compared with the solution of literature.     

Rigorous algorithmic targeting methods for hydrogen networks—Part I: Systems with no hydrogen purification

Hydrogen utility consumption minimization is one of the key strategies for reducing refinery operating costs. Process integration techniques have been widely accepted as an effective tool for reducing hydrogen consumption. To date, various pinch based conceptual methods have been developed. Applying the pinch analysis is simpler than solving the mathematical model. However, the relationship between the pinch simplification and the mathematical model has seldom been addressed. In addition, existing pinch analysis paid little attention to the rare but realistic cases of threshold problem. In this article, the original mathematical model is associated with the pinch concept by proving simplified equivalent formulations. A mathematically rigorous systematic targeting approach is then obtained by mathematical deduction. The proposed method combines pinch insight with a rigorous mathematical optimization technique. The proposed method addresses both threshold and pinch problems, and initially the analysis is restricted to systems with no purification unit.     

质量交换网络

质量交换网络自从1989年提出以来,作为发展循环经济和建设资源节约企业和社区的理论方法,获得长足进步。本文从基本概念、理论方法(特别是夹点分析方法)到工业应用做了全面综述。     

夹点技术及其在化肥行业的应用前景

介绍了夹点技术及其基本原理,对比了夹点技术与传统方法在节能降耗及工艺设计中的应用特点.分析了夹点技术在化肥行业中的应用前景和注意事项.     

基于夹点技术与超结构模型的多程换热网络最优综合

基于热力学原理,以夹点技术为基础结合数学规划法,采用两步法综合多程换热网络。第一步在多程换热网络热力学分析的基础上优化求解最小温差,计算公用工程用量。第二步将求得的最小温差作为夹点温差,将网络分为夹点之上和夹点之下两个子网络,建立多程换热网络的超结构模型,确定流股匹配并优化网络配置。最后,以换热网络总费用最小为目标,连接两个子网络,权衡设备投资费用和操作费用,综合多程换热网络。该方法基于热力学原理,改进了夹点技术在多程换热网络综合中的应用,进而实现了多程换热网络的自动综合。示例分析证明了本文所提方法的有效性。     

无分流换热网络合成和控制的集成研究

提出了无分流换热网络合成和控制集成的策略和方法、步骤,建立了合成和控制同步优化的数学模型,使得换热网络的合成和控制的集成研究从试探法向数学规划方法发展,从理论研究向实用性方向发展,实现了同时考虑控制要求的换热网络的自动合成。通过示例说明了本文所提方法的有效性和实用前景。     

A rigorous targeting algorithm for resource allocation networks

Techniques of process integration can be applied to conserve resources such as energy, freshwater, cooling water, hydrogen, solvent, etc. Process integration methodologies are broadly classified into two categories: methodologies based on the mathematical optimization techniques and methodologies based on the conceptual approaches of pinch analysis. In this paper, a mathematically rigorous methodology is proposed to minimize the requirement of a natural resource in a chemical process industry. The proposed methodology combines the simplicity of the pinch analysis with the mathematical rigor of mathematical optimization techniques. Conservation of resource in a chemical process industry is posed as a network flow optimization problem and a simple algebraic methodology is proposed to solve the optimization problem. The proposed algebraic methodology is mathematically proved in this paper. The proposed algorithm is numerically faster than the general mathematical optimization methods used for solving optimal resource allocation problems.     

Raw material management networks based on an improved P-graph integrated carbon emission pinch analysis (CEPA-P-graph) method

Raw material management plays an essential role in the environment production and carbon emission problem. A P-graph is an effective tool that can be used to solve the raw material management problem. However, raw material management based on the P-graph is complicated and inaccurate. Therefore, this paper proposes an improved P-graph integrating carbon emission pinch analysis (CEPA-P-graph) method to resolve raw material management problem with simpler structures and less results. The proposed method is applied in raw material planning in terms of the regional energy planning problem, and two ethylene plants under carbon emission constraints are examined. As the parameter information of the problem is utilized by pinch technology, the search domain of structure optimization is further reduced, and the computing complexity is reduced, while the advantages of the P-graph multi-solution are guaranteed. The experimental results demonstrate the validity of the proposed method. Furthermore, the CEPA-P-graph could reduce the complexity of solution structure generation by ~70% and reduce the carbon emission per unit product by 17%.     

具有多个不同质量资源网络的设计与目标值确定

This paper presents a new design procedure for the networks with multiple resources, such as hydrogen and water, of different qualities. The minimum consumption targets of the resources and pinch-causing sources can be identified as well during design. The objective of this work is to reduce the consumption of the resources with higher quality due to their higher cost. A few examples are investigated to show the proposed method. For a net-work of single resource with single contaminant, there is often only one pinch point for the resource. On the other hand, for a network of multiple resources with single contaminant, there might be a few different pinch points. Each resource might have its own pinch point, if its amount is sufficient. The contaminant concentration of the pinch-causing source for a resource with lower concentration will be below that of the higher-concentration resource(s).     

换热网络操作夹点分析与旁路优化控制

换热网络夹点设计法是从设计的角度,针对某一给定的典型操作条件而进行的,而炼油化工过程的生产条件经常在一定范围内波动。在实际的生产中,换热网络的操作夹点和最小温差与设计值往往不尽相同,为换热网络的优化控制带来了一定困难。因而近年来对于换热网络夹点技术以及旁路优化控制方面的研究不断深入,但将夹点技术与换热网络控制集成的方法仍不成熟。本文从操作的角度求解并分析换热网络结构已定或网络正在运行情况下的操作夹点,定性分析操作夹点的变化规律,并提出在操作夹点附近设置旁路实现网络的旁路优化控制,从而将夹点技术应用于换热网络旁路优化控制中。实例仿真表明,这一旁路优化控制方法在满足控制要求的同时明显降低了网络的总公用工程,验证了其有效性。