利用夹点技术分析优化碳酸二甲酯装置换热网络

利用Aspen Plus软件计算出冷流股和热流股的焓变,然后运用夹点技术对碳酸二甲酯反应精馏装置换热网络进行优化分析。计算结果表明,优化后的换热网络节能效果较好。通过小试数据,可以推断中试乃至工业化装置的换热网络节能情况。     

利用夹点技术设计换热网络

介绍夹点技术的基本概念以及利用夹点技术设计换热网络的原则,列举利用夹点技术设计换热网络过程的实例,并简单介绍换热网络优化方面的基本知识。     

甲基叔戊基醚合成新工艺

采用离子交换树脂催化剂对甲基叔戊基醚的合成工艺进行了系统的研究，取得了较佳的工艺条件，并进行了调合性能的考察，汽车辛烷值得提高。     

应用夹点技术实现换热网络的优化

文章首先介绍了过程能量综合方法夹点技术的基本原理,后在对东北某石化厂常压装置模拟的基础上用夹点技术对其原油换热网络进行了节能改造优化。改造后的换热网络同原有的换热网络相比,节省了加热炉需提供的部分热量,从而节省了大量的燃料油,同时冷却负荷量也降低相同数量,避免了公用工程的双重浪费;而且本着利旧的原则充分利用了现有闲置的换热器;各段和全局的传热温差变化比较均匀,同时换热网络的总传热系数也得到较大提高。     

夹点技术及其在换热网络中的应用研究

首先阐述了夹点技术的基本原理,利用夹点技术对原油常减压蒸馏装置的换热网络进行设计,运用问题表法求取夹点温度、最小公用工程。     

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。     

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。     

基于夹点技术的汽油加氢装置换热网络节能研究

为了保障炼油厂加氢炼化装置的有效运行、解决资源浪费现象,要基于现有的换热网络,利用夹点技术完成分析。通过数据换算以及模拟,可以了解夹点技术加氢电化装置换热网节能效果较佳,将夹点温差设置为20℃,可以计算出该装置的换热网络夹点温度为125℃。最小的工程计算量为10 449 kW,最小冷公用工程量为49 193 kW。由此可见,换热网络不合理情况执行的对应节能改造方案,可节能约57.89%的热公用工程以及27.76%的冷公用工程,有极佳的经济效益。     

甲基叔戊基醚裂解催化剂的催化性能

介绍了SPC-01型催化剂在甲基叔戊基醚(TAME)裂解生产异戊烯中的工业应用。该催化剂具有良好的活性和稳定性,TAME转化率和异戊烯的选择性均超过99%。利用X射线衍射(XRD)、热重分析(TG-DTA)、红外光谱(FT-IR)和孔结构分析对新鲜的和从装置卸出的催化剂进行表征,并对催化剂活性下降的机理进行了讨论。结果表明,在长周期运行中,催化剂比表面下降、结焦和酸性的损失是导致催化剂活性降低的主要原因,最后提出了TAME裂解催化剂的改进方向。     

Synthesis of multipass heat exchanger networks based on pinch technology

The multipass heat exchanger is the most common type of heat transfer equipment used in heat exchanger networks (HENs) by the chemical process industries. There are many methods that have been proposed for the synthesis of HENs with multipass heat exchangers, which are mostly derived from the FT design method. In this paper, an alternative new method to synthesis multipass HENs is presented based on the classical pinch technology. In the multipass heat exchanger, both countercurrent and co-current flow are involved. For the co-current flow, composite curves and problem tables are modified, and compared with that of the countercurrent flow. A proper minimum temperature difference is also selected considering the energy-capital cost trade-offs, and then a multipass HEN is synthesized. Results of the case study demonstrate that the new approach meets operating requirements and minimizes the total cost successfully.     

An area targeting algorithm for the synthesis of heat exchanger networks

A new algorithm for the prediction of area requirements in heat exchanger networks (HEN) is presented. The method uses a diverse pinch diagram as a basis, similar to the one suggested by Rev and Fonyo (Chemical Engineering Science, 46 (7), 1623). A numerical application for a problem involving streams with significant differences in their heat transfer coefficient values is included to show how the proposed algorithm provides better estimates for minimum area requirements in HEN than the widely-used Bath formula and the algorithm by Rev and Fonyo.     

基于热损失的换热网络夹点设计法

现行的换热网络目标方法,在进行换热网络价格估算时,未考虑热物流的热损失。在真实的设计中,换热器壳体保温后仍与环境温度相差较大,则其热损失不可忽略。文章提出了一个新的基于热损失的换热网络夹点设计法,该方法首先以综合费用最小为目标确定出最小温差,然后建立问题表格确定出夹点位置及最小公用工程消耗,最后再进行换热网络设计。文中采用某石油常减压换热网络系统为典型算例对该方法的前两步进行了分析研究,论证了该方法的必要性及可行性。结果表明:该方法与基本Linnhoff夹点技术法估算的投资费用有较大的差距之外,在一定的最小温差下,其与基本Linnhoff夹点技术法确定的夹点位置不同,公用工程消耗也有较大的差距。     

基于热容流率的换热网络夹点设计法

以Linnhoff换热网络夹点技术理论为基础,提出了在进行换热网络设计时,考虑热容流率随温度发生变化时确定夹点位置的方法,并结合实例进行分析计算。该法对夹点位置、最小温差、公用工程用量的确定更加准确,对投资费用的估算也更接近于实际。     

Supply and target based superstructure synthesis of heat and mass exchanger networks

This paper presents new methods for the optimisation of superstructures involving heat exchanger networks (HENs) and mass exchanger networks (MENs). The techniques developed in this study explore the use of key variables (namely supply temperatures/compositions and target temperatures/compositions) in HENs and MENs to define the intervals of superstructures. Such superstructures are modeled as mixed integer non linear programmes (MINLP) with the objective of minimisation of the total annual cost (TAC) for each network. The superstructures presented in this paper are derivatives of the interval and supply based superstructures (IBMS and SBS) developed previously. Two different superstructures are developed in this paper: the first uses the supply temperature/composition of hot/rich streams and the target temperature/composition of cold/lean streams (denoted supply and target based superstructure, S&TBS), while the second superstructure uses the target temperature/composition of hot/rich streams and the supply temperature of cold/lean streams (denoted target and supply based superstructure, T&SBS). Five HEN examples and three MEN examples are presented. The results obtained compare well with those in the literature.     

Hint: An educational software for heat exchanger network design with the pinch method

A free piece of educational software for heat exchanger network design based on the pinch method is presented. The interface of the program has been designed focusing on getting a clear presentation of the concepts of the pinch design methods and letting students the control of all the stages of the design. The program guides students through all the main steps of the design, including energy and cost targeting, utilities selection, heat exchanger network specification, and optimisation and retrofitting analysis. The program has been tested in a MSc pinch technology course for several years, and the feedback obtained from students during this period has been used to optimise the program functionality and its interface. The use of the program improves the efficiency of the course since it let students practice the concepts of the pinch method while relieving them of tedious repetitive calculations.     

换热网络填充函数法的全局优化

换热网络全局优化问题属于混合整数非线性规划范畴,其难点是目标函数和约束条件呈现为严重的非线性和非凸特性,局部最优解陷阱星罗棋布.针对其全局优化的难点,应用一种变换函数的全局优化方法--填充函数法,对换热网络进行全局优化.通过具体的填充函数对某特定算例进行求解表明,通过不断的交替优化,填充函数能够使换热网络目标函数跳出局...     

乙烯装置能量优化

应用夹点技术对某800kt/a乙烯装置低温系统的换热流程进行了优化分析。通过总组合曲线确定换热网络所需的不同冷剂等级及负荷,通过有效能组合曲线确定换热网络的有效能损失。经过调优处理确定合适的工艺流程,从而达到节能降耗的目的。