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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。 相似文献
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应用夹点技术实现换热网络的优化 总被引:6,自引:0,他引:6
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。 相似文献
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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。 相似文献
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换热网络操作夹点分析与旁路优化控制 总被引:3,自引:3,他引:0
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。 相似文献
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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。 相似文献
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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. 相似文献
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Medardo Serna 《Chemical engineering science》2004,59(12):2517-2520
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. 相似文献
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The objectives of the project reported here were to perform an energy analysis for the process of the recovery of ethanol from fermentation broths by catalytic conversion to gasoline and to conduct a pinch analysis to obtain a new heat exchanger network, and thus, reduce the utility costs. A minimum temperature difference of 10 °C was used. A temperature interval diagram and cascade diagram were drawn to identify the pinch points and four such points were observed. New heat exchanger networks were formulated from this information. The least number of heat exchangers for the different networks created was 19, whereas the original process had 9. The cost of utilities was the same for both systems. Therefore, it was concluded that the implementation of this system in the Caribbean could be expensive since in the first instance, ethanol is not particularly plentiful. Secondly, electricity and water costs are expensive in the Caribbean compared to other countries in America, such that any effort in reducing CO2 emissions by using ethanol would not be feasible. 相似文献
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Pinch Technology developed by Linnhoff and other workers has been widely adopted and considered to be one of the most successful techniques in process energy integration. The number of heat exchanger units is one of the most important aspects in the problem and Euler's formula has been applied in correlating the number of units and loops in the network. However, planarity of a graph is required for the application of Euler's formula, a fact that has been ignored in previous literature. It is demonstrated in this paper that Euler's formula cannot always be applied in Pinch Technology, by presenting examples of non-planar graphs resulting from thermodynamically feasible heat exchanger networks. 相似文献
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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。 相似文献
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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. 相似文献
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Optimization of heat exchanger networks (HENS) is a field of interest in Chemical Engineering. The aim is to use the residual heat of process streams to raise the temperature of other process streams which are cold, thus minimizing the use of hot and cold utilities. The usual way to deal with this task is to pose a linear programming problem according to a transshipment model in order to minimize either the general services consumptions or the number of hot and cold stream matchings required. This optimization is subjected to several restrictions given by the energy balances corresponding to each heat exchange.The high number of variables and equations obliges the use of specific software to solve these problems, e.g. GAMS (General Algebraic Modelling System). However, this software is not intuitive and requires a long time of training and a certain level of practice for the students to adequately use it.This work describes the use of Microsoft Excel-Solver for the sequential solving of HENS optimization problems according to the transshipment model. Solver is a much simpler, intuitive and easily available tool for the students who, besides, usually learn how to use it in the first years of their degree, in Informatics or similar subjects. Thus, it is not necessary to spend extra time in the teaching of the software, time that may be devoted to other contents.This paper presents an example of HENS problem proposed in the subject Simulation and Optimization of Chemical Processes corresponding to the Joint Master in Chemical Engineering of the Rey Juan Carlos University and the Autónoma University of Madrid and solved by the students using Excel-Solver. 相似文献