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高温空气燃烧技术通过回收烟气中的余热,实现高效节能.由于采用高温空气助燃,所以NOx的生成规律和常规燃烧不同.本文以5喷口带夹角烧嘴做为研究对象,通过数值模拟的方法对NOx生成进行了系统的研究,得出了助燃空气预热温度、助燃空气的含氧量、过量空气系数、空气射流的角度和钢坯吸热热流等5大因素对NOx生成的影响规律. 相似文献
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蓄热燃烧中NOx生成规律研究 总被引:1,自引:0,他引:1
蓄热燃烧技术通过回收烟气中的余热,实现高效节能.由于采用高温空气助燃,所以NOx的生成规律和常规燃烧不同.文章以五喷口带夹角烧嘴为研究对象,采用数值模拟的方法对NOx生成进行了系统地研究,得出了助燃空气预热温度、助燃空气的含氧量、过量空气系数、空气射流的角度和钢坯吸热热流等五大因素对NOx生成的影响规律. 相似文献
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以高温蓄热式加热炉为例,运用Fluent软件,研究了烧嘴喷口间距对炉内温度场、流速场分布的影响。研究结果表明:当烧嘴喷口间距增大时,虽然天然气和空气更容易扩散到整个炉膛燃烧,但是若距离增大到超过一定的程度,射流的偏转角度也会增大,造成炉内流速分布不均匀,降低炉膛内的平均温度,同时还会推迟天然气和空气混合,造成燃料燃烧不完全。当烧嘴喷口间距为450 mm时,炉内平均温度最高,而且温度分布最均匀。 相似文献
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几何结构影响高温空气燃烧特性的数值分析 总被引:1,自引:0,他引:1
通过改变燃料喷口周围空气喷口分布夹角,采用数值计算的方法研究了高温空气燃烧特性的变化,包括燃烧温度场、速度场和NOx的生成和出口排放情况。模拟结果说明,减小空气分布夹角可以降低燃烧区最高温度和平均温度,扩大燃烧室内低氧范围,有效抑制热力型NOx的生成和排放。所采用的计算模型和计算方法可以较好地模拟高温空气燃烧过程,计算结果可信。 相似文献
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一种新型烧嘴及其高效节能低污染特性分析 总被引:5,自引:1,他引:4
本文介绍了一种新型烧嘴的结构和工作原理。陶瓷蓄热体和切换阀是其两个主要部件。高温烟气和低温空气在切换阀的控制下,交替地通过陶瓷蓄热体,从而实现烟气余热回收和助燃空气的预热。助燃空气的预热温度可高达800℃以上。燃料被分成一次燃料和二次燃料两部分,总量很少的一次燃料与高温助燃空气在烧嘴内直接混合燃烧,而总量很多的二次燃料则被直接喷入炉瞠内进行高温低氧条件下的燃烧。文章对高温低氧燃烧方式的高效节能、低污染特性进行了分析。结果表明,采用高温空气燃烧技术实现60%的节能率和低NOx排放是可能的。 相似文献
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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) 相似文献
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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. 相似文献
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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". 相似文献
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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。 相似文献
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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. 相似文献
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TA Solokhina LS Shevchenko IuV Se?ku EG Rytik LV Besedina TS Veshchugina 《Canadian Metallurgical Quarterly》1998,98(6):42-46
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. 相似文献
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