CSTR热稳定性的另一标志──最大允许温差

在全混流反应器（CSTR）中进行放热反应,反应器要达到热稳定操作,必须同时满足定常条件（Qr＝Qg）和稳定条件,由此进一步导出在GSTR中进行n级不可逆反应及其对反应器热稳定性要求的另一标志──最大允许温差     

全混流反应器优化组合的讨论

在化工生产中为适应不同产品和不同反应的要求,常常需要各种不同型式的简单反应器(平推流反应器、全混流反应器等)进行各种组合(串联、并联等)。比如若干个全混流反应器的串联,可以减少返混的影响,使每个反应器中反应物的浓度维持在较高的水平。而循环反应器及其串联可以使原为平推流的反应器具有全混流的某种特征。但反应器的组合不仅要满足生产的要求(处理量F_(A0)和转化率XA等)而且要在满足生产要求的前提下尽可能做到优化组合,即使反应器的体积为最小,或者在反应器体积一定的情况下使物料的转化率或收率为最高。本文拟就全混流反应器的优化组合进行讨论。     

基于MATLAB在反应器优化设计中的应用

反应器设计过程中,如何确定最佳的操作条件,使得设计方案既满足工艺要求,又能降低设备投资及产品成本是一个非常重要的问题。本文利用MATLAB优化工具箱对具有循环操作的平推流反应器、全混流反应器与平推流反应器串联两种情况进行了优化,过程简便快捷。     

发动机冷却系统温差发电模拟试验台设计与开发

开发了用于模拟发动机冷却系统温差发电的试验台,实现了冷热端温度和输出电压的显示。利用该试验台进行了初步试验,研究结果显示:由于集热器存在一定的热阻使得热端温度低于冷却水温度,而散热器没有外部冷却导致散热效果较差使得冷端温度高于环境温度;而当采用风机冷却时,温差会变大,温差发电片输出电压明显升高;但当风速升高时,由于冷端和热端温度同时下降,变化效果不明显。     

侧沟式一体化OCO反应器水力过程建模研究

对侧沟式一体化OCO装置的水力过程进行了建模、拟合、校正,采用理想函数E（t）模型确定了装置的全混流比。研究结果表明：反应器在整体上趋于全混合式,全混流的比例为87.5%。     

新型一体化反应器的氧增加与衰减特性及水力学特性试验研究

中心岛式一体化OCO反应器是在传统氧化沟和OCO工艺基础上发展而来的一种新型反应器。以清水和混合液作为研究对象,对其溶解氧（DO）的增加与衰减特性进行了研究,并以清水作为研究对象对其水力学特性进行了研究。研究结果表明：以清水和混合液作为研究对象时,好氧区DO从0mg/L增加到2．0mg/L左右,需要的时间分别为30min和90min,装置内DO衰减直至稳定,需要的时间分别为15min和10min;水力学特性试验表明一体化OCO反应器水力混合特性趋于全混流,全混流的比例为96．8％。     

运用微分方程解决若干应用问题

微分方程是《高等数学》中的一个重点部分 ,应用微分方程的理论去解决科学研究和生产实践中遇到的实际问题 ,需要正确地列出微分方程。下面通过例题来分析微分方程的几种解题方法。1　直接“翻译”法 ,系指直接将问题中所给的变量之间的规律用数学式子表示出来。例 1:已知物体在冷却过程中遵守牛顿冷却定律 ,即“物体冷却的速率和当时物体与介质的温差成正比”。今把温度为 10 0℃的物体置于温度为 0℃的介质中冷却 ,求物体的温度和时间之间的关系式。解 :Ⅰ解方程(ⅰ )对题中给出的规律进行“翻译”设ｔ时的温度 =τｔ时的冷却速率 =ｄτｄ…     

多釜串联反应器的性能检测

采用脉冲示踪应答技术对多釜串联的微型工业反应器的单釜、二釜和三釜串联模型进行了RTD停留时间分布测定,借助计算机对各模型进行数字特征计算,并在图中标绘出各模型的θ和E(θ)关系曲线。由最小二乘法对一釜实验数据回归的结果表明,该反应器液相混合均能满足全混流假设。它具有较好传质特性,为以化工开发为目标的连续流动体系的宏观动力学研究提供了依据。     

冷却介质温度对柴油发动机经济性影响的实验研究

研究了增压直喷柴油机冷却系在不同冷却出水温度及不同进水出水温度差条件下的燃油经济性变化特征,测试了柴油机在最大扭矩转速和标定转速时不同负荷工况条件下冷却系统进水与出水温差变化对柴油机油耗的影响规律。实验发现:在冷却系出水温度处于较高恒定温度条件下,随着进水与出水温度差的减小,柴油机油耗呈现下降趋势;柴油机在大负荷工况时,最佳油耗特性出现在高出水温度和较小进水出水温度差的时刻。     

油库大型化对防火堤耐火性能的影响

随着能源在社会经济中越来越重要的战略意义,油库大型化的趋势越发明显。大型油罐火灾难以扑灭,同时燃烧产生大量的热会使防火堤因高温而失效。现行防火堤的耐火极限在耐高温温度和耐高温时间上都不能满足大型油罐着火时的安全要求,通过假设条件建立传热模型、防火堤温度的实例计算,为从理论上解决大型油库防火堤耐火性能提升提供计算依据。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.