某反应釜进料加热器管板的应力和疲劳分析

采用三维参数化建模的方法,介绍了某反应釜进料加热器中,承受压力和温度双循环载荷的固定管板的有限元ANSYS分析情况。得到分析结果后,进行强度评定,判断该管板在循环载荷作用下是否安全。     

醋酸乙烯聚合反应系统热失控与安全泄放

醋酸乙烯聚合过程操作不当会发生热失控,导致暴聚,安全泄放能力是防止聚合反应釜发生超压事故的关键。为此,利用VSP2绝热量热仪,针对冷却失效、引发剂量大、甲醇溶剂进料量低等主要危险情景开展醋酸乙烯聚合失控实验研究,计算反应釜安全泄放面积。通过对比不同温升速率、压升速率、反应温度下的TMRad等失控反应特征数据发现,引发剂量过大的工况为最危险情景;在65℃时,反应压力曲线基本闭合,确定反应体系为温和型蒸气系统。采用Leung法和平衡速率模型进行了安全泄放量、泄放能力计算,并利用校正系数Kc、流量系数Kd进行安全泄放面积校正,获得了反应釜的最小安全泄放面积。     

化工生产中反应釜温度控制系统的设计研究

随着社会的不断发展,反应釜被广泛应用于制药、化工等领域中。但就当前的现状来看,反应釜温度控制在化工生产中仍然存在着某些不可忽视的问题,为此,基于化工领域可持续发展背景下,应注重强调对反应釜温度控制系统的优化设计,并注重结合反应釜工作特性,选用最优控制器参数,达到高效、稳定温度控制状态,提升控制系统整体的运行水平。     

反应釜温度控制系统设计

反应釜是化工生产过程中最重要的反应设备,在反应的过程中,有大量的吸热、放热的现象发生,而反应釜的温度控制就成为了非常关键的技术。通过介绍反应釜的设计以及优化反应釜温度控制系统,从而提高化工产业的经济效益。     

连续搅拌釜式丙烯聚合反应器的模拟（Ⅰ）反应器的定态模拟

以实际工业装置为背景，建立了丙烯液相本体聚合连续搅拌釜式反应器的定态数学模型。通过模拟计算，考察了诸工艺参数──进料温度、进料流量、夹套冷却水人口温度和流量、丙烯蒸汽冷凝量、催化剂浓度以及反应器中的氢浓度对聚合反应釜反应结果的影响，并对其定态操作行为作了理论上的解释和分析。     

化学反应釜微机集散控制系统

介绍的化学反应釜微机集散控制系统采用智能Smith模糊控制算法,使反应釜的温度获得最佳控制效果.用3台下位微机对3台1吨化学反应釜的温度系统进行自动控制,由1台上位微机进行管理,实现了控制自动化,管理现代化,提高了产品的质量,节能效果明显.     

连续反应釜温度控制系统的设计与仿真

针对连续反应釜中进行的化学反应特性,按照过程的动力学方程和能量平衡等关系,设计了一套基于西门子PCS7的连续化学反应釜(CSTR)温度控制系统。由于连续反应釜内温度的非线性、时变等特性,采用变结构模糊控制结合前馈、串级、分程等先进的控制方式,克服了传统PID算法参数调整复杂、超调量大的缺点。仿真结果表明:对温度采用变结构模糊控制能获得较好的稳态精度和动态特性,满足了反应釜内温度控制的要求。     

连续搅拌釜式丙烯聚合反应器的模拟：（I）反应器的定态模拟

以实验工业装置为背景，建立了丙烯液相本体聚合连续搅拌釜式反应器的定态数学模型，通过模拟计算，考察了诸工艺参数－－进料温度、进料流量、夹套冷却水入口温度和流量、丙烯汽冷凝量、催化剂浓度以及反应器中的氢浓度对聚合反应釜反应结果的影响，并对其定态操作行为作了理论上的解释和分析。     

反应釜温度控制研究现状与化工自动化发展

反应釜在生产过程中占据非常重要的地位,其与产品质量密切相关,因此有必要深入分析反应釜温度控制系统现状,结合目前化工自动化发展,为我国工业生产水平不断提升打下坚实的基础。基于此,就反应釜温度控制研究现状与化工自动化发展展开论述。     

国产分散控制系统在化工中间体BFE生产中的应用

阐述了国产分散控制系统WebField GCS在化工中间体BFE生产控制系统异地新建方案中的应用。通过先进的控制方案,解决了反应釜的真空压力控制和温度曲线控制难题。     

流化床反应器中气相丙烯聚合反应的动力学和预测控制(英文)

A two-phase dynamic model, describing gas phase propylene polymerization in a fluidized bed reactor, was used to explore the dynamic behavior and process control of the polypropylene production rate and reactor temperature. The open loop analysis revealed the nonlinear behavior of the polypropylene fluidized bed reactor, jus- tifying the use of an advanced control algorithm for efficient control of the process variables. In this case, a central- ized model predictive control （MPC） technique was implemented to control the polypropylene production rate and reactor temperature by manipulating the catalyst feed rate and cooling water flow rate respectively. The corre- sponding MPC controller was able to track changes in the setpoint smoothly for the reactor temperature and pro- duction rate while the setpoint tracking of the conventional proportional-integral （PI） controller was oscillatory with overshoots and obvious interaction between the reactor temperature and production rate loops. The MPC was able to produce controller moves which not only were well within the specified input constraints for both control vari- ables, but also non-aggressive and sufficiently smooth for practical implementations. Furthermore, the closed loop dynamic simulations indicated that the speed of rejecting the process disturbances for the MPC controller were also acceotable for both controlled variables.     

反应釜温度控制的研究现状及化工自动化发展现状

反应釜广泛应用于发酵、化工、制药等工业生产中,其温度控制直接影响产品的质量和产量。文章概述了反应釜的特点,介绍了反应釜温度控制的研究现状,阐述了化工自动化的发展现状,最后在展望中指出,将化工自动化PID控制与预测控制结合使用,可有效调节反应釜的温度,提高产品的质量和产。     

OPTIMAL TEMPERATURE PROFILE IN METHANOL SYNTHESIS REACTOR

An optimal temperature profile is determined for a methanol synthesis reactor of LURGI type. The temperature profile is estimated so that methanol production rate in the reactor outlet will be maximized. First, the reactor is simulated based on heterogeneous one- and two-dimensional models. The comparison of the simulation results and plant data shows that the heterogeneous one-dimensional model can reliably be used for determining optimal temperature profile. Since optimal temperature profile for reversible exothermic reaction in tubular reactors is a decreasing function of reactor length, the technique of control variable parameterization is used for determining optimal temperature profile in a methanol reactor. In this way, a third order polynomial is considered for the temperature profile and the polynomial coefficients are as decision variables. The optimization is based on a Quasi-Newton's method (BFS technique), and the objective function is methanol flow rate at the reactor outlet. The results of optimization indicate that if optimal temperature profile is implemented in the reactor, methanol production will significantly be increased.     

Optimal temperature profile in methanol synthesis reactor

An optimal temperature profile is determined for a methanol synthesis reactor of LURGI type. The temperature profile is estimated so that methanol production rate in the reactor outlet will be maximized. First, the reactor is simulated based on heterogeneous one- and two-dimensional models. The comparison of the simulation results and plant data shows that the heterogeneous one-dimensional model can reliably be used for determining optimal temperature profile. Since optimal temperature profile for reversible exothermic reaction in tubular reactors is a decreasing function of reactor length, the technique of control variable parameterization is used for determining optimal temperature profile in a methanol reactor. In this way, a third order polynomial is considered for the temperature profile and the polynomial coefficients are as decision variables. The optimization is based on a Quasi-Newton's method (BFS technique), and the objective function is methanol flow rate at the reactor outlet. The results of optimization indicate that if optimal temperature profile is implemented in the reactor, methanol production will significantly be increased.     

Optimal oxygen concentration strategy through an isothermal oxidative coupling of methane plug flow reactor to obtain a high yield of C2 hydrocarbons

An optimal oxygen concentration trajectory in an isothermal OCM plug flow reactor for maximizing C₂ production was determined by the algorithm of piecewise linear continuous optimal control by iterative dynamic programming (PLCOCIDP). The best performance of the reactor was obtained at 1,085 K with a yield of 53.9%; while, at its maximum value, it only reached 12.7% in case of having no control on the oxygen concentration along the reactor. Also, the effects of different parameters such as reactor temperature, contact time, and dilution ratio (N₂/CH₄) on the yield of C₂ hydrocarbons and corresponding optimal profile of oxygen concentration were studied. The results showed an improvement of C₂ production at higher contact times or lower dilution ratios. Furthermore, in the process of oxidative coupling of methane, controlling oxygen concentration along the reactor was more important than controlling the reactor temperature. In addition, oxygen feeding strategy had almost no effect on the optimum temperature of the reactor. Finally, using the optimal oxygen strategy along the reactor has more effect on ethylene selectivity compared to ethane.     

苯酐生产中固定床反应器模型的研究

固定床气相反应器是苯酐生产中的主要设备,通过对比苯酐生产中不同固定床气相反应器操作法的优缺点,选择了低空气比率法作为固定床气相反应器研究对象。引入苯酐固定床气相反应器的反应动力学模型、转化率及温度分布模型、固定床反应器传热系数模型,并通过计算机对数学模型进行模拟计算得到数据,绘图得到相关曲线。通过对曲线进行分析,得出了与实际数据相符合的结论,该模型的建立不但可以优化固定床气相反应器的设计、生产,而且对苯酐生产中固定床气相反应器控制起到了指导作用。     

Use of nonlinear transformations and a self-tuning regulator to develop an algorithm for catalytic reactor temperature control

Prior to developing a multivariable control scheme for conversion and production rates in a packed bed tubular reactor carrying out highly exothermic reactions, it was important to stabilize the reactor temperature. In this paper we illustrate the use of a self-tuning regulator to develop an inner loop controller that satisfies some necessary conditions on temperature response, and that is capable of controlling the reactor over a wide range of operating conditions. The importance of using a nonlinear transformation of the reactor hot-spot temperature is demonstrated. Varying the input constraining parameter in the “one-step optimal” self-tuning controller is shown to be a very effective way of achieving a controller with the desired properties for response smoothness.     

液相法三相淤浆床甲醇合成技术

液相法三相淤浆床甲醇合成技术是一种使用三相淤浆床反应器将合成气转化为甲醇的生产新技术。与传统生产工艺相比，三相淤浆床甲醇合成工艺具有单程转化率高，出口甲醇质量分数高；床层等温，反应条件优良；温度易于控制，换热简单；生产的技术经济指标优良等特点，因此成为一种应用前景非常广阔的新兴甲醇生产新技术。     

Dynamics and stability of ethylene polymerization in multizone circulating reactors

Multizone circulating bed reactors (MZCR) have the exclusive characteristics of producing polymers of different molecular weights in a single particle. Traditional fluidized bed reactors, on the other hand, can produce only one kind of molecular weight with relatively narrow distribution. A dynamic model for the MZCR is used to illustrate the basic dynamic behavior of the new reactor design used for polyethylene production. The model is used to study the copolymerization of ethylene with butene. Several parameter sensitivity analyses are performed to show the computer-simulated time responses for reactor temperature, number-average molecular weight, weight-average molecular weight, catalyst feed rate and the monomer/comonomer concentration along the reactor length. At certain operating conditions dynamic instability is observed and the results for the effect of cooling water temperature, catalyst feed rate, monomer and comonomer initial feed concentration on the reactor temperature and polymer molecular weight reveal that the system is very sensitive to disturbances in the heat exchanger coolant temperature. Also, at some operating conditions, the reactor temperature oscillates above the polymer melting temperature. Temperature runaway above polymer softening point is a serious problem which may cause polymer melting and hence reactor shutdown. The oscillatory behavior of the reactor temperature necessitates a suitable temperature control scheme to be installed.     

基于Aspen Plus的焦炉煤气甲烷化工艺模拟及分析

焦炉煤气作为优质的二次能源,利用焦炉煤气甲烷化合成天然气(SNG)是焦炉煤气资源化利用的最佳方式。借助Aspen Plus软件,采用BWRS状态方程,设定主要工艺参数,对绝热式三段固定床焦炉煤气甲烷化工艺进行模拟计算分析,通过调节循环率和水蒸汽添加量控制反应器出口温度,模拟结果与实际试验数据较吻合,证明模拟可靠。考察了循环率、分流率、原料气组成、进口气压力和空速对反应器出口温度和组成的影响,结果表明循环率和分流率对反应器出口温度和转化率影响明显。