余热蒸汽发电机组真空度低的处理

正1问题的提出柳钢转炉余热蒸汽发电采用凝汽式汽轮机组。凝汽器的任务是:在汽轮机的排汽口建立保持高度的真空,使进入汽轮机的蒸汽在汽轮机膨胀到尽可能低的压力,增加蒸汽在汽轮机中的理想比焓降,提高循环热效率;将汽轮机的排汽凝结成洁净的凝结水,重新送入锅炉循环使用,达到回收工质的目的。2017年1月、2月,转炉余热蒸汽发电机组凝汽器真空度一直偏低,在进水温度28℃,凝汽器真空负荷为4.0 MW时,真空度达到了极限值-68 k Pa,影     

汽轮机系统真空度下降原因的分析

介绍了汽轮机凝汽器的真空度降低与凝汽器换热、真空系统严密性、冷却水的温度、流量、机组的排汽量及抽气器的工作状况有密切关系。通过分析影响凝汽器真空度降低的不同因素,采取有效的措施,保持机组经济真空运行。     

汽轮机凝汽器换热异常的分析及处理措施

凝气式汽轮机的凝汽设备起着冷源的作用,其主要任务是将汽轮机排汽凝结成水并在汽轮机排汽口建立与维持一定的真空度,凝汽器设备换热的好坏,对汽轮机装置的真空度、效率、功率有重大影响,直接影响到整个汽轮机组的热经济性。文章对汽轮机凝汽器端差、循环水温升和凝汽器入口、出口水温等影响凝汽器换热效果的因素进行了分析,提出了换热问题的处理方法、本机组凝汽器异常的处理方法和日常维护的注意事项。     

莱钢3^#105m^2烧结机优化控制系统

济南钢铁总公司干熄焦系统的主要设备为2套70t／h干熄炉，2台产汽35t／h的余热锅炉及1台6100kW的背压发电机等。干熄焦工艺过程是将由焦炉推出的约1000℃的红焦利用循环氮气熄灭，并使焦炭温度下降到250℃左右，循环氮气的温度上升到800℃，循环气体经过锅炉时，本身所带的热量使锅炉产生大量的蒸汽，蒸汽经过减压与减温以后，送入汽轮机组用于发电。     

汽轮机低真空供暖系统的优化与实践

本钢板材发电厂33号机采用低真空供暖，供暖形式为循环水通过4台板式换热器对热网回水进行加热。为了满足供暖需求，真空在-70 kPa左右、排汽温度在70℃左右，该工况若长时间运行，则会造成凝汽器铜管与管板之间胀口松脱，影响机组安全稳定运行。为此将凝汽器改造为热网凝汽器，即非采暖期凝汽器将汽轮机乏汽冷凝，回收凝结水；采暖期凝汽器直接作为热网换热器，为热用户提供余热水。     

2#汽轮鼓风机凝汽器技术改造

天铁2#汽轮鼓风机机组改造后汽轮机汽耗量增加,运行中出现了凝汽器真空缓慢下降,凝汽器端差增大,汽轮机排汽温度显著升高等问题,影响鼓风机正常运行。通过分析计算发现原有凝汽器冷却面积不够用,并提出了2#汽轮鼓风机和备机4#汽轮鼓风机的凝汽器连接的具体措施,取得了良好的效果。     

控轧控冷对38CrMoAl钢盘条硬度的影响和工艺优化

Φ8～20 mm 38CrMoAl钢(/%:0.35～0.42C,0.20～0.45Si,0.30～0.60Mn,≤0.035P,≤0.035S,1.35～1.65Cr,0.15～0.25Mo,0.70～1.10Alt)的生产工艺为90 t转炉-LF-VD-150 mm×150 mm方坯连铸-连轧。分析了成分、轧制温度、冷却速度对38CrMoAl钢组织的影响。通过将铸坯加热温度、开轧温度和吐丝温度分别由(1100±40)℃,(1020±20)℃(和(900±15)℃降至(1060±40)℃,(980±20)℃和(840±15)℃,同时降低冷却线辊道速度,盘条HB硬度值由284～353降至221～254,显著降低冷拔过程的断丝率。     

火力发电厂循环冷却水系统节能改造

凝汽设备是火力发电厂汽轮机装置的一个重要组成部分,其工作状态直接影响整个机组的热经济性和运行可靠性。文章对某发电公司湿式凝汽器的循环冷却水系统进行分析和研究,指出其存在的主要问题,并提出了改造方案,此方案对于火力发电厂海水直流冷却系统的设计优化和节能改造有借鉴意义。     

高炉用铜-钢复合冷却壁传热及力学性能分析

采用热力耦合方法研究了铜层厚度和冷却水道间距对铜-钢复合冷却壁温度及应力分布的影响.以1∶1比例铜-钢复合冷却壁进行了热态试验,测试了铜-钢复合冷却壁温度分布,计算了热态试验条件下铜-钢复合冷却壁的温度分布,计算结果与试验结果基本吻合.计算结果显示,铜-钢复合冷却壁铜层厚度增加,壁体最高温度和最大等效应力减少,铜层厚度上限值为70mm;冷却水道间距减少可以降低壁体最高温度和最大等效应力,当冷却水道间距小于220mm时,减少冷却水道间距对降低壁体最高温度和最大等效应力作用较小.铜层厚度为60mm,冷却水道间距为220mm的铜-钢复合冷却壁在高炉热负荷较高区域工作不易发生塑性变形损坏.     

TA15钛合金板材单向拉伸超塑变形行为研究

采用TA15钛合金板材,研究了在860～980℃,8.3×10-4～1.7×10-3s-1条件下进行的超塑拉伸性能。结果标明:随着变形温度的升高,延伸率先增加后降低;在940℃、应变速率为1.7×10-3s-1、垂直轧制方向获得最大延伸率为1370%。随着变形温度的升高和拉伸速度的降低,等轴α晶粒尺寸增大。变形温度为940℃时诱发次生α相的析出,少量的层片组织对提高延伸率具有一定的作用。     

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。     

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。     

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.