生物质成型燃料锅炉的结构特性研究

为了提高了锅炉的燃烧效率和热效率,根据生物质成型燃料特性及燃烧规律的试验分析,采用链条炉排,增强了炉膛燃烧强度;高且加长的的炉膛使得生物质成型燃料在炉膛内燃烧的燃烬程度增加：通过热工计算设计了生物质成型燃料锅炉,达到了设计的目的。     

固定床式气化炉内部流场的数值模拟研究

以固定床式煤气化炉发展兴起的型煤富氧气化技术是符合我国能源战略政策的新技术。为掌握现有气化炉生产特性,采用计算流体动力学软件进行数值模拟。在建立与实际相对应的常压气化炉几何模型基础上,选用k-ε双方程模型、流体输运模型、SIMPLE方法求解N-S方程、P1模型,模拟出炉膛内的组分浓度场、温度场,为进一步研究炉内的燃烧状况、优化燃烧过程和指导生产工艺改进提供了理论依据。     

"土暖气"与冬天取暖

素材观察 冬天,在北方的不少家庭中安有燃煤取暖炉,俗称"土暖气".下图是某品牌煤炉的结构简图: 它的工作过程是:煤在炉膛中燃烧,炉膛周围的水被加热,这样水管中的水温度就升高了,散热片就热了,人们就可以取暖了.     

前后墙对冲燃烧锅炉内CO分布原因的数值分析（英文）

目的:前后墙对冲燃烧锅炉在实际运行中普遍存在沿炉膛宽度CO体积分数呈中间低、两边高的分布特点。该分布特点往往伴随着锅炉效率降低、炉膛出口NOx排放偏高、侧墙结渣和高温腐蚀严重等一系列问题。本文旨在分析前后墙对冲燃烧锅炉内CO分布规律的形成原因,为机组运行调整与燃烧系统改造等工程实践提供理论依据。创新点:1.针对煤粉炉燃烧过程中存在剧烈气固反应流的特点,定义了与气、固相质量变化无关的风、煤分布系数ηa和ηp,进而得到了风/煤混合系数η。2.对比炉膛不同区域内的CO分布与风/煤混合系数分布,结合炉膛的空气动力学特性,解释了前后墙对冲燃烧锅炉内CO分布特征的形成过程。方法:1.建立一台660 MWe前后墙对冲燃烧锅炉的数值模型,并通过现场测量数据与模拟数据的比较,验证模型的有效性(表5和图3)。2.定义炉内风、煤分布系数与风/煤混合系数(公式(1)～(3))。3.对比不同特征截面上CO分布特性与风/煤混合特性,探讨二者之间的关联性(图4和5)。3.分析风的分布和煤的分布分别对风/煤混合特性的影响(图6和7)。4.综合考虑炉内气流结构、风和煤的分布及其混合特性,揭示炉内CO分布规律的形成原因(图4～9)。结论:1.对前后墙对冲燃烧锅炉而言,燃烧器区域出口的CO大量聚集在炉膛中间至侧墙区域,燃尽风区域出口的CO则主要集中于侧墙附近。2.CO分布与风/煤混合系数分布基本一致。3.在整个炉膛空间内,风和煤粉皆有向侧墙流动的趋势,但煤粉更加聚集在侧墙周围。4.在燃烧器区域,对冲气流使得风与煤粉向侧墙流动,然后在炉膛四角形成涡流;四角涡流导致烟气在沿侧墙上升的过程中发生明显的气固分离,使煤粉被甩至侧墙附近并在那里燃烧,形成高浓度CO;5.在燃尽风区域,燃尽风与侧墙附近烟气的混合并不理想,因此侧墙附近的高浓度CO难以消除,最终导致沿炉膛宽度的CO体积分数呈中间低、两边高的分布特点。6.基于上述结果,本文分析了当前应用中存在的问题,并提出了改进建议。     

循环流化床锅炉燃烧系统热工特性

为了保证燃烧的稳定性和循环的持续性,燃煤ALSTOM型300MW CFB锅炉炉膛内部都有大量不可燃固体颗粒,一般占到炉膛总物料量的97%以上.这种方式使得流化床燃烧具有对燃料适应性好,有害气体排放低等优点.流化床燃烧在电站锅炉、工业锅炉、窑炉和焚烧各种废物、水泥等领域得到了广泛的应用.     

水平排布方式预爆轰点火过程的数值模拟

为了研究预爆轰点火对脉冲爆轰发动机燃烧转爆轰过程的影响,采用二维CE/SE计算方法对脉冲爆轰发动机预爆轰点火过程进行数值模拟研究。分析了预爆轰点火方式和管径比对主爆轰管内起爆过程的影响。数值计算表明:采用预爆轰点火方式可以有效实现燃烧向爆轰的转捩,最终形成可以稳定传播的爆轰波,在此过程中激波在管壁和中心轴线上的反射起到了非常重要的作用。预爆轰管和主爆轰管的管径比对燃烧转爆轰有显著的影响,增大管径比可以有效缩短DDT距离和时间,对爆轰波强度影响甚小。     

基于火焰图像的工业炉氮氧化物排放检测技术

通过CCD工业摄像机采集工业炉膛火焰图像,运用松弛迭代法对火焰图像进行分割,使用燃烧火焰图像处理技术,得到影响炉膛温度场变量。利用偏最小二乘法(PLS)将锅炉运行参数和温度场变量联合构建一个输入数据矩阵,对锅炉煤燃烧过程中氮氧化物排放量进行预测,并同实测值进行对比。结果表明:该方法对预测氮氧化物排放量的准确度高,误差小,为实现工业炉在线监测提供了一种手段。     

智能驾驶员模型的Excel仿真及运动学分析

智能驾驶员模型用于自由流和拥堵流状态下的行驶车辆行为的描述,具有物理意义明确,模型参数少等优点。利用Excel软件的迭代计算和动态模拟功能实现了该模型的计算机仿真,动态的实现了车辆的跟驰行驶过程。仿真中实现模型参数化,可以观察到各种参数对模型的影响,对车辆跟驰过程中车辆运动参数的变化和模型的特征进行分析带来便利。仿真方法中各种公式和数值计算过程清晰可见,而且不需要开发者有计算机编程经验,也可对其他类型的跟驰模型仿真、验证及实验教学提供参考。     

墙式燃烧锅炉无油启停磨煤机在长电公司的研究和应用

通过煤粉在炉膛内爆燃机理分析,指出无油启动磨煤机防止煤粉爆燃关键因数;通过对墙式布置旋流燃烧器煤粉气流在炉膛内着火情况分析,提出无油启动磨煤机在墙式燃烧锅炉上的应用依据;通过对长兴发电有限责任公司无油启动磨煤机的实际应用情况分析,证明有条件无油启动磨煤机在墙式燃烧锅炉上应用的安全性.     

发动机燃烧模拟器温度场分布研究

不论是在发动机中还是在燃烧模拟器内,边界条件对燃烧过程起着十分重要的影响.文章针对自行研制的定容燃烧模拟器温度场分布进行了相关的试验研究,测取了大量内部温度数据,得到了在现有加热模式状态下燃烧模拟器内的温度场分布规律.研究表明,在本燃烧模拟器内的几何中心温度与平均温度存在较大差异,这一结果说明在本燃烧模拟装置中,测试点的温度并不能代表模拟器的平均温度,也不能代表最高温度,在模拟燃烧的计算过程中,应充分考虑装置中温度分布规律及其对着火过程的影响.     

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!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.