乙烯装置汽油分馏塔系统中循环急冷油流量对产品的影响

分析了高温裂解热回收系统及其汽油分馏塔系统,并提出可能的节能方案,由于该节能方案会引起循环急冷油流量的改变,因此需要对节能方案的影响进行分析.作者通过对汽油分馏塔进行分析和简化,选用了相应的模型和方法,以循环急冷油流量为自变量,裂解气和燃料油产品为因变量进行灵敏度分析,得出循环急冷油流量在很大范围内波动不会影响产品的质量及后续流程的改变,说明所提出的节能方案可行.     

人工免疫动态克隆调节策略在分馏装置塔板效率确定中的应用

在石油化工领域中,分馏过程是流程模拟计算中重要的模块之一,在分馏过程模拟的主要输入参数中,塔盘效率无法直接获得,因此确定合适的塔盘效率是分馏模拟成功与否的关键因素,探索合适的方法确定板效率是精馏模拟的重要课题。本文在板效率确定方面,引入人工免疫动态克隆优化调节策略DCAS,与传统的智能优化算法相比,该算法的特点为:自动调整搜索空间及克隆规模;采用多尺度变异策略;有机结合全局与局部搜索能力。在实验中,通过建立分馏装置的机理模型,并采集装置的实际工况数据和各流股质量组成的分析数据,对所采集的数据依据稳态过程的物料守恒方程等进行剔除和校正处理,采用校正后的工况数据作为模型的输入,分别用经验法、遗传算法GA及人工免疫动态调整策略DCAS确定分馏装置的塔板效率,使模型与实际装置达到最大程度的吻合。研究结果表明,用DCAS确定的塔板效率,能够使分馏塔的关键塔板温度分布及分馏塔塔顶、塔釜主要产品的产出与实际吻合得最好,表明用DCAS搜索的塔板效率建立的分馏塔模型能够较好地描述实际分馏塔的生产过程,可以用来指导分馏装置的过程模拟及优化操作。     

延迟焦化主分馏塔模拟策略研究

以一种可灵活调节循环比的延迟焦化工艺为背景,在运用流程模拟软件PRO/II进行模拟计算的基础上,重点探讨了焦化主分馏塔的模拟策略,如反应油气组成预测、气液平衡计算中热力学方法的选定、塔板效率的选取、分馏塔脱过热段模拟简化模型的建立等。主分馏塔模拟结果表明,脱过热段与分馏塔分馏段单独模拟处理能更好地反映装置的实际运行情况。     

MTBE蒸馏脱硫工艺模拟

为使中国汽油达到欧V汽油的含硫标准,研究蒸馏脱硫工艺的可行性有实际意义。以甲基叔丁基硫醚为关键含硫组分,使用Aspen Hysys v 7.0模拟其与MTBE分离过程。按MTBE单塔蒸馏、双塔能量集成蒸馏和与分馏塔能量集成3种方案脱除硫化物,进料硫化物含量100μg/g的条件下,塔顶MTBE含硫化合物1μg/g,3种方案吨产品蒸汽消耗分别为0.233t、0.13t和0.08t。MTBE中含硫化合物与MTBE容易分离,简单精馏可以实现深度脱硫。双塔能量集成方案比单塔直接分离方案节水50%,节约蒸汽45%。MTBE脱硫塔与MTBE分馏塔或催化蒸馏塔进行能量集成,不增加冷却水,蒸汽消耗每吨MTBE增加小于0.1t。辅助塔可以使硫化物浓缩到99%(m/m),MTBE含硫化物30μg/g,可以混兑低硫产品中或循环回分离系统,MTBE几乎无损失。     

乙醇脱水制乙烯工艺流程模拟研究

本文开发了一种乙醇脱水制乙烯工艺。为降低装置能耗,提高乙烯回收率,乙烯精制单元采用由脱重塔和脱轻塔组成的双塔分离工艺,以避免使用高能耗的深冷分离设备。本文运用PRO/II流程模拟软件建立了乙醇脱水制乙烯全流程工艺模型,通过研究乙烯精馏单元精馏塔的理论塔板数、进料位置、回流比等参数对乙烯分离效果的影响,确定了较优的工艺操作条件;通过全流程模拟计算,得到全装置总体物料平衡,乙烯产品纯度达到99.98 wt%,乙烯回收率达到99.5%,乙烯精馏部分单位产品能耗为1.03MJ/t。     

浆态床费托合成分离系统的流程模拟与优化

针对目前浆态床费托合成工业装置中分离系统运行中出现的尾气换热分离器换热性能差、重质油带水、易堵塞等问题,通过流程模拟对神华宁煤400万吨/年费托合成装置的分离系统进行了分析。模拟结果表明,现运行工况下换热器冷侧气体最低温度(70℃)远低于水蒸汽露点温度(123℃),因此局部换热不均时会造成热气体过冷,从而导致水蒸汽冷凝、重质蜡和催化剂粉沫黏附堵塞。在模拟分析的基础上提出了两级换热流程,保障换热分离器在露点温度以上操作,避免重质油带水和堵塞问题;模拟结果表明,新流程可降低单系列尾气空冷器负荷32 MW,增加单系列反应器蒸汽产量49 t/h,降低全厂年生产成本1亿元左右,节能增效显著。     

基于分析的乙烯装置蒸汽系统操作优化

针对乙烯装置蒸汽系统的操作参数优化问题,从系统能效视角提出了一种基于分析的优化方法。在建立蒸汽供应和转换设备模型的基础上,依据蒸汽系统的结构建立了各级蒸汽的平衡模型和约束方程。基于Aspen Plus流程模拟软件建立了乙烯过程的流程模拟系统,建立了可计算蒸汽和动力需求的非线性黑箱模型。通过集成蒸汽平衡模型、设备模型和流程模拟黑箱模型,以蒸汽系统能效最大为优化目标,采用两步计算方法,可得到蒸汽系统内各设备的最优操作条件。乙烯装置的实例分析验证了该方法的有效性。     

蜡油催化裂化装置的先进控制应用策略

详细论述了催化裂化装置的控制策略,利用先进控制的模型预估控制功能,提高装置的平稳程度,多变量预估控制的应用可以减少MV变量的变化,同时保证CV变量的平稳,主要表现在温度、液位和产品质量的平稳上;提高装置处理量和掺渣量及高价值产品收率;实现产品质量卡边控制：包括汽油干点、柴油95％点、稳定汽油RVP等;降低能耗：主要是降低泵负荷以及蒸汽的消耗。实现催化裂化反应再生系统、主分馏塔和吸收稳定系统的前馈控制和动态解藕．提高了对装置的控制水平。镇海300万吨／年催化裂化联合装置的先进控制经过一年多的投用,降低了关键变量的波动方差,得到了操作人员的欢迎．由于先进控制与工艺的密切关系,随着工艺改造和生产方案的变化,周期性地对先进控制的维护是用好先进控制的基础,加大了用好先进控制的难度。     

加氢裂化分馏塔多目标优化操作和产品方案分析

应用流程模拟技术对加氢裂化分馏塔进行了模拟,在此基础上,建立了以航煤量、柴油量、尾油量、加热炉温、塔底蒸汽量、柴油侧线蒸汽量、中段回流量为优化操作变量,以产品总值和能耗为优化目标的加氢裂化分馏塔优化模型。应用改进强度Pareto进化算法(SPEA2)求解多目标模型得到Pareto前沿。基于Pareto前沿各产品量的分布,确定了多产航煤、多产柴油与多产尾油3种方案的优化操作点,并给出了3种产品方案优化操作点的雷达图,此雷达图为产品方案的调整提供了一种可视化手段。本文方法对加氢裂化分馏塔多产品方案的操作优化具有参考作用。     

受流股分流限制的石化工艺装置换热网络分析

石化工艺装置在工艺和流程优化的基础上,通过夹点分析可以确定换热网络的最小热、冷公用工程量;同时,为增加装置热能回收利用效率,通常利用夹点之下的余热生产相应压力等级的蒸汽。但是,在工程实践中,由于石化装置冷物流的分流限制,导致夹点之上的热量并不能全部用于加热冷物流,不可避免的引起热量穿越夹点换热。基于夹点技术,建立流股受分流约束的换热网络混合整数线性规划模型。将建立的模型应用于某延迟焦化装置,通过模型求解,获取不可避免的穿越夹点的换热量,指出在夹点附近处冷、热流股的合理匹配方案,并对比分析受流股分流限制和不受流股分流限制的冷、热公用工程,结果表明建立的模型能够为石化工艺装置换热网络设计或改造提供技术支持。     

Control of Motion of a Body in Formation of a Channel in a Fluid

Mechanics of the formation of a channel by a head of a bending body is considered. Equations are derived of the motion of the body in the channel with its simultaneous formation, which contain the positive feedback. Control is described of various modes of motion and also the transition from one mode to another, including the transition to the motion on account of the feedback. The clarified interrelation of the pressure of the body, its speed, and the responses of the fluid makes it possible to describe the mechanics of the formation and deformation of the channel, which denies the possibility of motion of the body on account of the positive feedback.     

On a Parametrization of Purifications of a Qubit

This work provides, constructively, explicit one–one parametrizations of all purifications of a mixed state in dimension 2 and all joint purifications, if any, of two mixed states in the same dimension. The former is parametrized by SO(3, R), while the latter is parametrized by SO(2, R), except when the state being purified is already pure. These parametrizations are derived without any passage to the spectral decompositions of the state(s) being purified. Using this, we show how to calculate certain measures of quantum information. The appendix considers an alternative one–one parametrization of mixed states in C² C², which provides a different explicit construction of joint purifications. PACS: 03.67-a; 03.67-Hk; 03.67-Lx     

Design of a pH titrator as a component part of a personal computer

Personal computers are becoming almost as common as pocket calculators. In particular, their use in laboratories for measurement and control is growing. The next step after computer-controlled instruments is the development of a personal computer with an instrument as a component part. An automatic pH titrator has been designed. The system presented is based on an Apple Ile. Two plug-in cards are used. One card integrates analogue measurement and analogue-to-digital conversion. The other card controls a syringe driven by a stepper motor. The software control system for the personal pH meter is also described.     

A design of a controller as a component of a robotic manufacturing system

This paper specifies the functional design of a robot or machine tool controller suitable for inclusion in robotic manufacturing systems. The principle interest is the unmanned manufacturing cells which are being developed as major components of new manufacturing facilities. The functional specifications are motivated by recent experiences with the creation of a prototype cell for an open die forging process. There are two key technical design requirements. The first relates to the robot or machine tool being controlled. The controller must direct the machine actions, and, for unmanned operation, the controller must receive and process sensor information for process modification and for fault tolerance. The second relates to communication with the central cell computer (the host). The operation of an unmanned system requires a robot communication channel between the host and the controller; the controller must also respond to a variety of instructions transmitted from the host. Additional controller design requirements are imposed by economics. The proposed controller can be used today, and can develop in an evolutionary manner to meet the needs of future manufacturing systems. The evolutionary development is made possible by modular design, organized in a hierarchical manner.     

On a nonlinear problem of a sequential control with a parameter

The problem of evasion of a group of moving points from a nonlinear controlled object, whose goal is consecutively approach these points in a prescribed order, is analyzed. The movement of each point is defined uniquely by a scalar parameter chosen at the initial time instant. The controlled object minimizes a certain cost function, and the group of the points, acting cooperatively, maximize this cost function by choosing the parameters. Necessary optimality conditions for parameters are obtained. A model problem of an evasion of moving points from a vehicle is solved.     

Three-Link Mechanism as a Model of a Person on a Swing

Journal of Computer and Systems Sciences International - We model movements of a person swinging on a swing. We consider a flat three-link hinged mechanism as the main mechanical model of the...     

Implementation of a model of a metainformation-controlled editor of information units with a complex structure

This paper describes the model and methods for implementing an extensible tool for editing information with a complex structure with different levels of abstraction and invariance to technological spaces (subject domains) in a common conceptual framework for carriers of this information; this makes it unnecessary to arrange specialized training for these carriers or involve professional intermediaries.     

Algorithmic selection of a disassembly sequence of a component by a wave propagation method

The design of a product for its entire life-cycle is becoming more and more important. Nowadays, a product is designed with significant considerations for its manufacturability, serviceability, its functionality and even for its disassemblability. This is due to the fact that the modern consumers demand products that are not only functional, but also reliable, easy to repair and also environmentally friendly.For maintenance and re-use, the operation sequencing in disassembly process planning needs of reversible operation selecting.We present a new wave propagation disassembly algorithm of the determined component of a product; the given data are the immediate predecessors of each component.We show that the solution exists and that she is unique in the following conditions: the binary matrix of the immediate predecessors is non-symmetrical and the data does not contain a cycle. A tracked down cycle method in the data is also proposed.     

Diffusion of a chemically reactive species of a power-law fluid past a stretching surface

A numerical solution for the steady magnetohydrodynamic (MHD) non-Newtonian power-law fluid flow over a continuously moving surface with species concentration and chemical reaction has been obtained. The viscous flow is driven solely by the linearly stretching sheet, and the reactive species emitted from this sheet undergoes an isothermal and homogeneous one-stage reaction as it diffuses into the surrounding fluid. Using a similarity transformation, the governing non-linear partial differential equations are transformed into coupled nonlinear ordinary differential equations. The governing equations of the mathematical model show that the flow and mass transfer characteristics depend on six parameters, namely, the power-law index, the magnetic parameter, the local Grashof number with respect to species diffusion, the modified Schmidt number, the reaction rate parameter, and the wall concentration parameter. Numerical solutions for these coupled equations are obtained by the Keller-Box method, and the solutions obtained are presented through graphs and tables. The numerical results obtained reveal that the magnetic field significantly increases the magnitude of the skin friction, but slightly reduces the mass transfer rate. However, the surface mass transfer strongly depends on the modified Schmidt number and the reaction rate parameter; it increases with increasing values of these parameters. The results obtained reveal many interesting behaviors that warrant further study of the equations related to non-Newtonian fluid phenomena, especially shear-thinning phenomena. Shear thinning reduces the wall shear stress.     

Motion control of a rotor with a cavity with a viscous fluid

A formulation and solution procedure of optimal control problems for perturbed relative uniform motion of a body with a cavity filled with a viscous incompressible fluid are proposed. In this paper, the case with a cylinder is considered; however, this approach is basically true for the a cavity of an arbitrary form. The formula for the angular velocity of perturbed motion depending on an external perturbing element is devised. After that, we have a possibility to set different optimal control problems and apply the formalism elaborated in the optimal control theory. Two illustrated problems are given.