高压蒸汽冷凝液膨胀蒸汽综合利用

本溪北方化工公司尿素生产装置采用的是水溶液全循环法工艺流程,吨尿素耗蒸汽1.8 t左右。在尿素生产过程中,一、二段分解加热器和一、二段蒸发加热器输出的1.30 MPa高压蒸汽冷凝液(189℃)只有少部分用于尿素管线保温和冬季采暖。而该公司双氧水生产所需的0.50 MPa蒸汽,是由1.30 MPa高压蒸汽通过压力调节阀控制到0.50 MPa后使用。若能将尿素生产过程中一、二段分解加热器和一、二段蒸发加热器输出的高压蒸汽冷凝液膨胀产生0.50 MPa蒸汽并送双氧水生产线综合利用,可降低蒸汽消耗。1高压蒸汽冷凝液状况尿素生产高压蒸汽加热器有4台,共产生…     

聚合干燥工序加热系统的工艺优化

正甘肃银光聚银化工有限公司PVC厂聚合工序采用0.4～0.6 M Pa低压蒸汽加热空气的工艺干燥PVC树脂,蒸汽与空气经空气加热器换热,加热后的高温蒸汽冷凝液(90℃)送至辅助车间离心母液处理单元。运行过程中,空气加热器气锤严重,造成翅片换热器泄漏,高温蒸汽冷凝液及其热能未实现高效利用。笔者通过认真分析空气加热器的工作性能和高温蒸汽冷凝液的特性,对干燥加热系统进行了工艺优化,实现了高温蒸汽冷凝液全部回用。     

汽轮机轴封加热器问题的分析处理

1系统介绍我公司余热发电中的7.5MW补汽凝气式汽轮机,轴端汽封由均压箱供给压力为3～30kPa,温度为130～180℃的蒸汽,轴封所排蒸汽在轴封加热器中经凝结水冷却后,由轴加风机排向大气,在轴封加热器中部分蒸汽凝结为水后经轴封加热器下面的U型疏水管道直接排向地沟。     

空分装置分子筛运行能耗浅析

分子筛加热系统是分子筛正常运行的一个重要组成部分。目前大多数空分装置分子筛加热都采取蒸汽加热或与电加热器串联加热的方式,达到分子筛再生的目的。介绍了某空分装置分子筛纯化系统,该系统蒸汽加热与电加热器串联使用时,通过控制系统优化电加热器加热时间比例,既避免了富余蒸汽资源的浪费也能更好地节约电能。     

新型蒸汽加热器的研发和应用

简单介绍了蒸汽加热器的发展历程,对两种形式蒸汽加热器的结构作了比较,阐述了新型蒸汽加热器的工艺流程、关键技术及创新点,以及产品应用情况和取得的成绩,指出了其作为新一代产品的研发价值。     

酸浴蒸发加热器的改进

以石墨列管加热器取代用于酸浴蒸发的铅列管加热器。在加热器内部加入四个支撑架,以减小列管受蒸汽冲击时出现的弯曲变形;采用环式进气方式,使蒸汽均匀地进入加热器中,以减少蒸汽对列管的冲击。石墨列管加热器可比铅列管加热器显著提高对酸浴的处理效果和节省蒸汽用量。     

硝酸钾生产节能技术应用

在硝酸钾生产中采用了蒸汽直接加热溶解氯化钾、空气冷却结晶、二效蒸发、蒸发后溶解硝酸铵、干燥机加热器串联进蒸汽等节能新技术,显著降低了硝酸钾能耗与生产成本,每生产1t硝酸钾可降低蒸汽消耗为2622kg。     

硝酸钾生产节能技术应用

在硝酸钾生产中采用了蒸汽直接加热溶解氯化钾、空气冷却结晶、二效蒸发、蒸发后溶解硝酸铵、干燥机加热器串联进蒸汽等节能新技术．显著降低了硝酸钾能耗与生产成本．每生产1t硝酸钾可降低蒸汽消耗为2622kg。     

压延生产线温控系统加热器的改造

在压延生产中,压延机应进行加热,压延机所使用的温控系统有蒸汽加热和电加热两种。蒸汽加热为饱和压力蒸汽同循环水在换热器中进行换热,具有加热速度快、热源稳定、维修简便,但不易控温及造价高、占地面积大等缺点。因此中、小型压延机多采用电加热方式。电加热是使用电加热器直接加热循环水,其成本低、占地面积小、维护方便。但是当循环水突然中断、循环水浊度较高、自动排汽阀失灵等情况发生时,加热器内蒸汽无处排放,使循环水液面下降,造成加热器干烧,即电加热器温度过高而烧毁、爆裂,容易造成电气线路短路、接地等情况的发生,具有一定的…     

蒸汽加热器技术及发展

介绍了空分设备配套的几种蒸汽加热器的结构类型,重点介绍了近年来新开发的低翅整体轧制式蒸汽加热器的优缺点和再开发及结构改进的情况,分析造成该类蒸汽加热器泄漏的主要原因.提出了质量控制的方法和手段。     

顺丁橡胶凝聚过程模拟与节能分析

顺丁橡胶水析凝聚工艺为橡胶生产工艺能耗的主要环节,为了研究影响顺丁橡胶双釜水析凝聚工艺能耗高的原因,在对国内某炼化企业顺丁橡胶水析凝聚工艺进行全面调查的基础上,建立顺丁橡胶双釜差压式凝聚工艺计算模型,通过模拟查找影响凝聚工艺能耗高的因素,对比分析模拟结果与实际生产数据,提出节能明显的双釜差压式凝聚工艺以及热泵双釜差压式凝聚工艺,新旧工艺对比,新凝聚工艺节能效果明显。     

反渗透膜元件的微分方程数学模型

在反渗透膜元件的理想结构模型基础上建立了反渗透膜元件运行的微分方程数学模型,在分析膜元件运行参数的基础上确认了微分方程的边界条件,从而使微分方程组具有惟一解。膜元件运行微分方程模型的建立为膜元件及膜系统运行精确模拟计算软件的编制提供了数学基础。     

Anwendung experimenteller Labormodelle bei der Voraussage der Leistung von Gas/Flüssigkeits-Reaktoren

The role and use of experimental laboratory-scale models for predicting the performance of an industrial gas-liquid reactor. The aim of the present work is to illustrate the usefulness of experimental laboratory-scale models for simulating the operation of industrial gas-liquid reactors. After defining the term simulation and establishing the necessary simulation criteria, the authors present various experimental laboratory-scale models and characterize them by the criteria so as to enable selection of one of these models for simulating the operation of an industrial gas-liquid contactor. The respective principles of the differential and integral simulation of an industrial absorber by a “point” model or by an “integral” model are discussed and illustrated with the aid of practical examples. The differential simulation of a packed column by a laboratory agitator vessel and the integral simulation of a pilot scale liquid motivated venturi jet scrubber by a laminar jet are dealt with in detail. Finally, a few industrial applications of this technique published in the literature are presented.     

聚合物3530S对坨一原油各组分油水界面性质及乳状液稳定性影响

用界面张力仪、表面粘弹性仪和Zeta电位仪研究了聚合物3530S对胜利坨一原油各组分模型油与模拟水间的界面特性及乳状液稳定性的影响规律。结果表明,沥青质及胶质模型油与模拟水间的界面张力低于蜡组分模型油,原油中的界面活性组分主要为沥青质和胶质。聚合物加入模拟水后,含有聚合物的模拟水与沥青质、胶质及蜡组分模型油之间的界面剪切粘度与界面张力均上升,油滴表面的Zeta电位降低。沥青质和胶质模型油与含聚合物3530S的模拟水所形成的W/O乳状液较蜡组分模型油所形成的W/O乳状液更稳定。     

基于特征线法的一阶双曲型分布参数模型辨识及其在烟气脱硫过程中的应用

引言在现代控制工程领域中,许多工业对象实际上是非线性分布参数系统。由于这类对象的复杂性,原始模型常常进行集中线性化处理后分析和设计控制系统,然而系统本质的分布特性以及非线性引起的模型失配将造成控制的失败。这种情况促使在先进控制中越来越多地直接采用非线性分布参数机理     

Periodically operated trickle-bed reactor for EAQs hydrogenation: Experiments and modeling

The influence of periodic operation on a consecutive reaction, the hydrogenation of 2-ethylanthraquinones (EAQs) over Pd/Al₂O₃, on a laboratory-scale trickle-bed reactor (TBR) was studied. The effects of operating parameters including cycle period, split, pressure, temperature, and time-average flow rate on the performance were experimentally examined in comparison with the steady-state operation. The results showed that under the interested operating conditions the conversion and the selectivity improved by 3-21% and 1-12%, respectively. A dynamic model consisting of a set of partial differential equations (PDEs) was developed to simulate the periodic operation of TBR for EAQs hydrogenation. The PDEs were converted into a set of ordinary differential equations (ODEs) using the method of lines (MOL) and then numerically solved by the semi-implicit Runge-Kutta method. The developed model was verified by simulating the effect of cycle period and split on the conversion and the selectivity enhancement and compared with the experimental results. It was found that the model was reliable and satisfactory when the cycle period was less than 200 s.     

方型多火嘴石油化工管式炉中辐射室三维流动及传热的数学模拟

提出方型石油化工管式炉中辐射室的三维流动和传热的数学模型.对某焦化炉计算的结果与实测数据进行了初步比较并作出讨论.     

Particle population model for a fluidized bed with attrition

For a steady-state fluidized process, a population model for particle mixtures undergoing both attrition and reaction is developed. Populations of different materials affect each other through ways such as attrition. The evolution of the attrited fines is more realistically assessed so that the differential solid balance is consistent with the overall mass balance. The possible effects of fines on the attrition and reaction are considered too. Effects of several input and operational conditions on the process performance are discussed and demonstrated by a simulating program. Many particle population models in the literature can be seen as special cases of the present model. The model represents a more realistic approach to the simulation of the fluidized-bed process.     

MODELING OF CONCRETE SLABS UNDER FIRE*

The ability to assess the integrity of concrete structures after a severe thermal shock is extremely important not only for fire safety but also for the economy. A mathematical model, capable of rationally determining of fire response and correctly simulating the heat and mass transfer in concrete structures has been developed. Based on the concept of continuum mechanics, the conservation of mass, momenta, and energy equations have been used to yield a set of three coupled nonlinear partial differential equations with time dependent nonlinear mixed boundary conditions. Approximately a finite difference model has been developed for simulating the concrete structure under fire. The discrete set of implicit finite difference equations, after being quasi-linearized, is used and solved by a computer. Efficiently controlling time-step, the running computing time is minimized without detrimental effects on accuracy. The numerical results predict the phenomenon of “moisture clog” and show that: the permeability of concrete is an essential parameter. This parameter controls the buildup of pressure during the fire exposure. The explosive spalling of concrete under fire is predicted.     

Modeling of the impregnation process during resin transfer molding

A model has developed for simulating isothermal mold filling during resin transfer molding (RTM) of polymeric composites. The model takes into account the anisotropic nature of the fibrous reinforcement and change in viscosity of the polymer resin as a result of chemical reaction. The flow of impregnating resin through the fibrous network is described in terms of Darcy's law. The differential equations in the model are solved numerically using the finite element technique. The Galerkin finite element method is used for obtaining the pressure distribution. A characteristics based method is used to solve the non-linear hyperbolic mass balance equation. The finite element formulation facilitates computations involving the motion of the polymer resin front characterized by a free surface flow phenomenon.