高炉炉缸炉底内衬的等效冷却条件计算方法

建立了高炉炉缸炉底冷却的二维有限元传热模型.该模型能计算紊流水冷冷却器以等效对流换热系数表征的冷却参数,能反解服役炉缸实际冷却强度.等效冷却条件参数可用于缩小多维炉缸传热模型的计算域和规模,且不失边界条件精度.文中设计了参数化有限元建模及分析的计算程序,基于管内紊流水努赛尔特征数,定义一个物性综合系数,构造了更为简明的对流换热系数计算表达式.     

2500m~3高炉炉缸炉底侵蚀监测模型的开发与应用

高炉炉缸炉底是影响高炉寿命的限制性环节之一。为了避免发生严重侵蚀甚至烧穿等重大事故,针对马钢2 500 m~3高炉,开发了利用热电偶或者冷却设备数据监测炉缸炉底侵蚀监测模型。采用该模型,监测了马钢2 500 m~3高炉的炭砖残存厚度变化。该模型可用于判断炉缸炉底是处于侵蚀阶段还是处于堆积阶段,对高炉操作者分析、判断和调节炉况有指导作用。     

炉缸冷却壁对流换热系数计算及烘炉传热特性

 炉缸冷却壁冷却性能主要体现在冷却水与水管间的对流传热。因为工程上常用计算对流换热系数的经验公式不能满足不同的水流状态从而导致炉缸热应力分析误差较大，所以以某高炉炉缸结构为例，首先利用传热学准数方程推导出冷却水处于不同流动状态时对应的综合对流换热系数表达式，同时探讨了对流换热系数经验公式的适用范围；然后通过迭代计算推导出了冷却水处于层流状态下考虑衰减热阻时的综合对流换热系数表达式；最后对烘炉状态下炉缸侧壁传热模型进行瞬态传热与冷却分析，得到了微水烘炉甚至闭水烘炉的热工依据，可为初步制定高炉烘炉制度进行评估和完善。     

高炉冷却壁与炉气之间的换热特性

 基于边界条件替换方法建立了高炉冷却壁本体和捣打料与炉气之间的换热系数计算模型。用试验测量冷却壁近热面温度来推算冷却壁热面温度，与冷却壁温度场计算模型结合，确定了炉气温度在500~1 248 ℃范围内，高炉冷却壁与炉气之间的换热系数。结果表明，本模型的计算值与前苏联学者的试验结果吻合。     

邯钢薄板坯连铸连轧衔接区板坯温度模型的研究

以邯钢薄板坯连铸连轧（CSP）工艺中直通式辊底炉中的薄板坯为研究对象,建立二维非稳态数学模型,采用差分法,以连铸结束的板坯温度场为初始条件,结合辐射和对流复合边界条件,对薄板坯进行了换热情况的数学建模和温度场计算。根据相关文献提供的技术数据及LOI公司的检测结果验证了所建模型的正确性,并提出对直通式辊底炉的炉温制度进行计算的合理方法。     

在线预测高炉炉底炉缸侵蚀模型的研究方法

采用有限元法、两点法和边界元法，分别建立了高炉炉底炉缸侵蚀的数学模型并分析了三种方法的特点。这些模型可离线或在线监测高炉炉底炉缸侵蚀状况。马钢2500m^3高炉炉底炉缸在线侵:高炉炉底炉缸1150℃侵蚀线处于第七层碳砖的中部位置，形如“象脚”。因此，认为高炉炉底炉缸侵蚀状况基本正常。     

武钢4号高炉炉缸炉底侵蚀预测模型的开发与应用

针对高炉炉缸炉底侵蚀状况在线监测的需要,以武钢4号高炉为研究对象,开发出了基于有限差分算法的炉缸炉底侵蚀预测模型软件。模型通过实时计算高炉炉缸炉底的截面温度分布,以及1150℃等温线的位置,反映当前炉缸炉底的侵蚀状况。软件运行结果表明,4号高炉炉缸炉底侵蚀状况较好,截面温度分布合理,炉缸炉底处于安全生产状态。     

马钢2500m~3高炉炉底炉缸侵蚀模型的研究

针对马钢2500m~3高炉,利用有限元法、两点法及两者相结合的方法,开发了高炉炉底、炉缸侵蚀的数学模型,该模型可离线或在线监测高炉炉底、炉缸侵蚀状况。研究结果表明,高炉炉底、炉缸1150℃侵蚀线处于第七层碳砖的中部位置,形如“象脚“。因此,认为高炉炉底、炉缸侵蚀状况基本正常。     

沙钢3号高炉炉缸炉底侵蚀结厚智能监测系统

高炉炉缸炉底耐材寿命是影响高炉一代炉役寿命的限制性环节,及时了解炉缸炉底的侵蚀情况并作出针对性调整措施至关重要。基于传热学、数值模拟、遗传算法等研究方法,结合炉缸炉底侵蚀、结厚的形成机理,利用炉缸炉底热电偶在线采集的温度数据,开发了沙钢3号高炉炉缸炉底侵蚀结厚智能监测系统。该系统还原了沙钢3号高炉整个炉缸炉底区域的温度场分布,实现了侵蚀结厚的动态模拟。此外,相比以往模型,本模型改进了人机交互方式,使炉缸炉底侵蚀结厚模拟结果以更加直观的图像与视频方式予以展示,从而使炼铁工作者更容易掌握炉缸炉底侵蚀现状及变化趋势。     

四号高炉炉底剩余厚度的计算

武钢四号高炉,有效容积为2516米~3,是目前我国最大的高炉。炉底采用立砌碳砖水冷结构。两层碳砖(1100×1;1200×1),两层高铝砖(400×2),炉底总厚度为3100毫米,是目前我国大型高炉最薄的炉底。为了监测炉底的侵蚀情况,砌砖时,在不同标高上埋设了放射性同位素。     

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。     

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。     

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.     

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。     

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。