国产大型煤压机防喘振控制技术的分析与应用

介绍煤压机喘振线的测试、计算和拟合以及防喘振控制策略。防喘振控制系统可生成防喘振曲线、动态增加防喘振控制偏差、实现自动／手动切换及控制、不对称输出、快开、压缩机防喘振状态指示等功能。实践证明,系统控制精度高,性能稳定,操作简单、直观、易懂。     

轴流压气机防喘振保护

轴流压气机防喘振保护是头等重要的问题,它的解决要以准确的特性曲线为基础,而准确的特性曲线只有通过实验的方法取得。文章结合天津铁厂高炉风机试验的实际,详细阐述了如何用实验的方法测得风机特性曲线,根据特性曲线制定出喘振报警线和防喘振放风线。同时,对定转速风机、变转速轴流压气机等不同机型采取不同的防喘振保护系统,并在生产中取得了极好的效果。     

轴流压气机防振保护

轴流压气机防喘振保护是头等重要的问题,它的解决要以准确的特性曲线为基础,而准确的特性曲线只有通过实验的方法取得。文章结合天津铁厂高炉风机试验的实际,详细阐述了如何用实验的方法测得风机特性曲线,根据特性曲线制定出喘振报警线和防喘振放风线。同时,对定转速风机、变转速轴流压气机等不同机型采取不同的防喘振保护系统,并在生产中取得了极好的效果。     

新钢10号高炉风机防喘振调节控制优化

随着原燃料品质的劣化和高炉冶炼强度的调整,新钢10号高炉风机运行工况点向喘振调节放风线趋近,操作时被迫将1号防喘阀打开15％左右,造成了能源浪费.在现场进行风机喘振性能试验后,重新设定了防喘振调节放风线,并对其他控制程序进行了优化.改造后,10号高炉风机1号防喘阀在正常生产时已全部关闭,风机产生的风能全部用于高炉生产,充分发挥了风机潜能,有效保障了机组安全生产.     

CCC防喘振控制器在转炉送风机中的运用

从控制方法的选择、喘振变量的计算、各种喘振控制线的确定以及CCC控制器在防喘振控制上的特点入手,对CCC防喘振控制器在某铜业公司转炉送风机防喘振控制系统中的应用进行了分析。实践证明,使用该控制器能充分保护风机并提高风机运行的经济性。     

高炉鼓风机防喘振控制系统的改造

结合涟钢高炉1#鼓风机防喘振控制系统改造的具体实例,介绍了喘振的形成和危害,阐述了防喘振控制的原理及控制系统的实现方法.     

高炉轴流风机喘振分析及防喘振控制系统研究

介绍了轴流风机喘振现象的形成机理、不同气温条件下喘振曲线的动态补偿方法,分析了常见的传统防喘振控制工艺中存在的不足,以及先进防喘振控制技术应用于高炉轴流风机的优化控制策略。     

空压机防喘振自动控制

介绍了离心式空压机产生喘振的机理,对喘振原因进行了分析.结合石钢公司2套制氧机组离心式空压机的工程设计、组态、防喘振控制的设计实例,分析了防喘振操作过程中容易出现的问题,对类似机组的DCS编程组态和操作控制具有一定的借鉴.     

大型煤气压缩机控制在燃气-蒸汽联合循环发电中的应用及改进

济钢燃气-蒸汽联合循环发电中的煤气压缩机,通过采用一拖三变频拖动、启停机联锁保护、防喘振线以及分段调节方式,对机组的安全启动、喘振保护和调节精度等进行改进和优化,不仅减少了投资,提高了机组的安全性,而且完全满足了燃气轮机所需燃料的精度要求,效果十分明显.     

高炉鼓风机防喘振阀气源技术改进

阐述了高炉鼓风机防喘振阀在运行中出现的问题及喘振产生的原因,对系统改进,提高了防喘振系统的工作可靠性.     

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。     

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.     

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。     

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.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.     

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)