中厚板轧后超快速冷却系统流量调节技术

 中厚板轧后超快速冷却水流量的控制速度直接影响轧机的轧制节奏,水流量的控制精度直接影响钢板冷却过程的控制精度。以应用于多家中厚板厂的一种新型超快速冷却设备为例,分析其电动调节阀的调节特性,给出提高流量调节速度和流量调节精度的有效方法,为超快速冷却设备和控制系统的优化设计提供参考依据。     

控制冷却模拟装置

本装置用于控制轧制、控制冷却模拟试验和为工厂建立轧后控制冷却装备提供工艺参数和设计依据。采用气-水喷雾冷却方式,上、下双面冷却,冷却均匀,节省耗水量,冷却速率可调范围广(从风冷到50℃/s以上),上部冷却和下部冷却分开控制,可随意调节上、下水量比,冷却后板形良好。气水比随意可调,可精细调节冷却速率,冷却速率控制精度为±2℃/s。装有气压、水压、气量、水量的控制调节和自动记录仪表。只需一人就可在操纵台上进行全部调节控制和操作。     

差分算法在宝钢冷轧连退冷却控制中的应用

介绍了目前冷轧连退机组几种主要的冷却工艺、宝钢几条连续退火生产线目前所采用的冷却工艺设备、它们各自所采用的冷却控制模型技术、差分算法在冷却控制模型的建模原理和应用效果.通过实际过程控制趋势图表,展示了过程变量差分控制模型在非稳态生产控制过程中的强大调节能力和良好的控制精度.     

中厚板卷厂控冷系统集管水流量控制

针对中厚板控冷系统冷却水流量控制问题,开发了一种新型的流量控制技术,通过对各个电动调节阀开口度和相应管道流量实测值采样,分析并计算出流量设定-开口度设定曲线 根据曲线计算出控制器的基本输出量,再根据流量计反馈与流量设定值的偏差用PID控制器进行闭环控制,使得冷却水流量的控制精度得到了提高。     

层流冷却控制模型在安钢炉卷轧机的应用及改进

控制轧制和控制冷却是现代化板材的主导生产工艺,用于生产优质的中厚板,层流冷却控制系统的控制精度直接影响产品的性能.安钢炉卷轧机采用层流冷却控制模型,对钢板通过层流冷却区域的速度和冷却水量进行控制,在实际使用中对影响其控制精度的一些因素进行了修正和完善,取得了良好的效果.     

层流冷却的前馈控制

为提高热轧带钢层流冷却卷取目标温度的控制精度,根据冷却过程的传热机理,分析了带钢层流冷却的传热过程.在此基础上,给出了冷却控制的空冷和水冷预测数学模型,分析并阐述了层流冷却控制系统的前馈控制算法及其在实际控制中的应用.本前馈控制的使用效果良好,具有较高的目标卷取温度控制精度,能满足生产的需要.     

湛钢厚板厂淬火机控制功能的改进

湛钢厚板厂的淬火机电控部分由东北大学设计建造,其目的是满足对淬火工艺的需要。结合生产实际,分析了淬火机的设备组成与控制结构,对淬火机控制的薄弱环节进行了说明。结合现有淬火工艺的分析和研究,对淬火机相关控制设备进行改进,实现淬火机辊道速度控制的灵活变化和提高弱冷段喷嘴调节精度等方案,摸索出一套适合现场的新的冷却工艺,有效地解决了工艺参数调整不灵活、资源浪费较多的问题,同时保证了设备控制精度。     

对用计算机控制萃取工艺中流量的探讨

用现代控制方法改造传统型设备，提高流量控制精度。     

烧结圆盘配料皮带秤控制新思路

通过分析烧结配料主要设备——圆盘配料皮带秤的工艺状况，找出了通常采用的控制方案的薄弱环节。提出了以累计料量控制为主，瞬时料流量控制为辅的控制思路。实践证明，该思路有助于提高累计料流量控制精度及料流量的稳定性。     

超快冷供水系统的研究与应用

国内某钢厂进行产线升级改造,以提高产品质量和扩展产品种类,新建轧后超快冷系统.超快冷系统是整个生产线工艺控制的关键工序之一,其水系统的合理设计则是超快冷系统良好使用的基础,对钢板冷却的均匀性、冷却能力、自动化控制都有较大影响.通过水系统工艺优化设计、设备合理配置、全自动变频控制调节,在实际生产应用中供水在0.2 MPa水压条件5 s内稳定,0.5 MPa水压条件10 s内稳定,流量稳定精度为±5 m3/h,实现了超快冷用水稳定、高效的目标.     

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。     

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。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.     

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.