高炉煤气燃烧锅炉控制系统的优化

锅炉控制系统控制的好坏关系着燃烧经济性和运行安全性。本文介绍了热电厂锅炉控制系统中的各个控制回路,并着重对高炉煤气燃烧锅炉控制系统进行分析和优化。     

煤气与燃煤混燃型300 MW火电机组协调控制系统改进研究

某钢厂在300 MW发电机组的锅炉燃烧系统中,增加了掺烧高炉煤气和焦炉煤气的燃烧装置。通过对机组煤气和燃煤混燃后的燃烧特性、主汽压力等重要参数的变化进行分析,引入针对于煤气、燃煤混烧的前馈系统,综合电负荷侧的能量需求,调整各个闭环控制回路中的参数变量,将改进后的协调控制系统应用于机组运行中,取得了良好的控制效果。     

欧陆微机数采系统在锅炉生产监控中的应用

１　系统构成我厂有４台２０ｔ工业锅炉，并有检测参数１００多点，控制回路主要进行锅炉汽包水位调节和锅炉燃烧系统控制。根据工艺要求每台锅炉必须单独监控，独立显示，又要能够集中监控和显示、记录。控制系统采用欧陆计算机数采系统监控网络结构，如图１所示。其中Ｔ３０００ＤＳ计算机工作站除用于程序开发、画面处理以及参数修改外，还可以用作实时运行和显示操作。Ｔ３０００ＲＤ计算机工作站，只用于实时运行操作和参数修改。Ｔ６４０调节回路控制器，用于实现调节系统的控制策略。４１８０Ｍ智能记录仪，用于过程数据的处理、显示…     

工业锅炉交叉限幅燃烧优化控制

工业锅炉是我国目前应用面宽、数量多的耗用一次能源的重要设备,每年消耗原煤达2亿多吨。锅炉运行效率的好坏对于我国节能具有重大经济意义。当前,我国中小型锅炉广泛采用链条炉排式,锅炉实际运行热效率远低于设计效率。造成热损失大的因素虽然很多,但与工业锅炉上没有建立起一套合理的实际可行的燃烧控制系统有很大关系。针对我国中小型锅炉实际情况,我们对SHL20-1320t/h工业锅炉采用了先进的分布控制,上位机采用1BM-PC计算机,下位机采用了SIMATICS5-605μ可编程控制器,成功地实施了燃烧优化控制,提     

160T／h工业煤粉锅炉智能集成控制技术的开发

针对锅炉生产过程中运行情况复杂,条件多变,为达到提高锅炉运行效率和燃烧效率,节约能源,提高锅炉运行的稳定性,研发了该智能集成控制系统。该系统是基于Rockwell公司的ControlLogix和RSVIEW组态开发环境,实现了过程控制软件的设计,包括连锁控制、基础回路控制和协调控制。     

燃气热水锅炉负荷调节控制系统的设计

对燃气热水工业锅炉燃烧控制系统的构成、控制原理进行了深入研究,介绍了一种先进的控制方案,即结合燃气流量计来精确控制燃气流量和空气流量的方法,实现了精确的空燃比控制,改善了燃烧性能,提高了燃烧系统的控制精度。     

JX-300X专家控制系统在锅炉燃烧过程中的应用

介绍了采用 JX-3 0 0 X专家控制系统对 75 t/h循环流化床锅炉燃烧过程进行自动控制的方法。通过应用专家智能控制系统 ,提高了锅炉的自控投运率和控制效果 ,提高了系统的运行可靠性     

模糊PID控制在工业锅炉控制系统中的应用

针对工业锅炉控制系统的特点,采用将常规PID控制与模糊控制相结合的控制策略,在常规PID调节器的基础上,采用模糊推理思想,根据不同的E、EC对PID参数Kp、Ki、Kd进行自校正。对锅炉汽包液位的控制表明这种模糊PID控制器可明显提高系统的性能。     

俄制500 MW机组锅炉送、引风机控制系统改造实践

针对某发电公司俄制机组锅炉送、引风机控制系统存在可靠性低、保护联锁功能不完善、运行人员劳动强度大等诸多问题,对其进行改造,送、引风机控制系统就地分别安装1套油站控制设备、1套振动监测系统、1套动叶调整设备以及电机温度检测元件。改造后,送、引风机及油站控制系统全部引入临近的DCS远程站,实现了远程操作、控制、监视等功能,优化了炉膛压力控制回路,提高了风机控制系统的可靠性,同时减少了运行人员的劳动强度。     

全燃气工业蒸汽锅炉的自动化控制过程实现

结合天津钢铁公司14t/h锅炉计算机控制系统,论述了蒸汽锅炉计算机控制系统的工作原理,锅炉控制中的几个重要的控制回路,及各个环节控制的实现方法。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.