共查询到20条相似文献,搜索用时 109 毫秒
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针对镁合金材料在摩托车发动机零部件上应用时散热性能差的传热特性,建立了发动机气缸头盖的有限元分析模型;提出了发动机气缸头盖有限元分析的传热边界条件的算法,通过镁合金和铝合金发动机气缸头盖在相同热边界条件下仿真分析的温度场分布情况进行了对比分析研究,反映了温度对镁合金气缸头盖的结构强度和耐热性能的影响;采取了增加镁合金气缸头盖散热片数量和散热片高度的方法来增加气缸头盖外表面的散热面积达到增加镁合金气缸头盖的散热能力的效果。 相似文献
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柴油机气缸内热辐射研究方法的探讨 总被引:1,自引:0,他引:1
作者从气缸内热辐射模型和实验两个方面探讨了气缸内辐射研究的方法。综述了气缸内热辐射理论和实验技术的进展,提出了气缸内辐射研究朝着多维化方向发展。 相似文献
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在考虑气缸垫材料非线性及螺栓弹性相互作用条件下,设计了缸盖螺栓顺序预紧与交叉预紧两种装配连接工艺,采用非线性有限元计算方法建立了机体、气缸盖、缸套、螺栓、缸套支撑及气缸垫组合结构有限元模型,研究了螺栓预紧顺序与气缸垫接触压力之间的关系,得出了满足组合结构气缸密封特性要求的较好装配连接工艺.对比了螺栓残余预紧力的计算值与试验值.结果表明:采用非线性有限单元方法可以实现对机体、气缸盖、缸套、螺栓、缸套支撑及气缸垫组合结构螺栓预紧装配连接工艺的较精确仿真计算;顺序预紧时,螺栓平均残余预紧力及残余预紧力标准差都大于交叉预紧;气缸密封最差区域出现在气缸垫排气侧两螺栓中间位置,两种装配连接工艺都能满足气缸密封性能要求,顺序预紧气缸密封最差区域密封效果更好. 相似文献
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本文介绍了柴油机气缸孔变形研究过程和工艺改进结果.研究结果表明:机械加工残余应力是气缸孔变形的主要原因;降低机械加工残余应力可以有效地控制气缸孔变形;改进珩磨工艺可以有效地控制气缸孔变形. 相似文献
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本文阐述新型金属气缸垫的开发、试制与应用.根据B6135柴油机非增压机型和增压机型的不同性能特性,先后研制了多层金属组合式和单层金属气缸垫,从而彻底解决了大功率柴油机在高压和高热负荷条件下的有效密封问题。该型气缸垫的开发成功,填补了国内大功率柴油机应用金属气缸垫的空白. 相似文献
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M. Hanafy H. I. Nabih 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(2):143-159
Abstract Oil/water emulsion is found in the wastewater effluent streams coming from various sources, such as the petroleum refineries, the discharge of bilge and ballast water, workshops, petrol stations, rolling mills and from edible oil and soap factories. The oil recovery process adopted will depend on how the oil is present in the water stream. Oil can be found as free floating oil, as an unstable oil/water emulsion and also as a highly stable oil/water emulsion. Free oil in wastewater is readily removed by gravimetric separators, while unstable oil/water emulsions can be mechanically or chemically separated. Stable emulsions and in particular those involving water soluble oily wastes require sophisticated methods to satisfy treated water legal requirements. This study is dedicated to the application of dissolved air flotation (DAF) for the removal of emulsified oils from oily wastewater. A dissolved air flotation unit has been designed for this purpose and the ultimate goal is to explore the technical viability of this technique. The design and then construction of the dissolved air flotation pilot plant has been conducted to treat 1.0 m3/hr of oily wastewater. The performance of the DAF system has been investigated using synthetic oil emulsions and true wastewater where three different types of oil have been managed. The various operating conditions have been tested to define the most appropriate conditions for processing oil/water emulsions. The effect of coagulant addition on the oil separation in the presence of an emulsifying agent is investigated. 相似文献
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通过对6号汽轮发电机组负荷异常降到零的故障分析,计算,比较了油温及间隙漏油对一次油压的影响,总结提出了维持一次抽压正常的几点建议。 相似文献
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机油稀释现象是发动机常见的试验表象之一,尤其是增压缸内直喷汽油发动机,机油稀释较明显。机油发生稀释后会破坏机油使用性能,降低运动粘度,严重时还导致机油压力下降,零部件功能丧失,发动机可靠性下降。主要分析一款1.8L GDI缸内增压直喷发动机产生机油稀释的影响因素进而对机油牌号、机油温度、水温、SOI角度、曲轴箱通风系统、活塞漏气量、喷油器布置方式进行Benchmark分析及优化验证,为改善增压直喷发动机机油稀释现象提供解决方法,机油稀释包括燃油喷射稀释和机油挥发稀释,重点探究的方向是燃油喷射稀释。 相似文献
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Bio‐oil is a promising alternative energy source to crude oil for broad application prospects. Bio‐oil can help us avoid over‐reliance on petroleum resources and significantly reduce pollutants and greenhouse gas emissions, improve environment conditions, and protect ecological systems. However, bio‐oil applications have been impeded because of limited technologies, and poor bio‐oil quality has posed a great challenge. As such, considerable research efforts have been made for realizing its potential application value. Scientific and technical advancements on methods of bio‐oil quality improvement to date are reviewed, with an emphasis on advantages and disadvantages of each method. It also points out barriers and gives some recommendations to enhance bio‐oil combustion performance in the future. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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介绍了电厂润滑油系统及主润滑油泵的结构,并依据系统流程及泵体构造分析了主润滑油泵振动异常的原因,提出了相关的预防措施及在检修过程中的重要控制点,以避免类似事故的发生,提高机组运行的可靠性和经济性,可供同类型机组设备参考、借鉴. 相似文献
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《Energy Policy》2015
The economic implications of oil price shocks have been extensively studied since the 1970s. Despite this huge literature, no dynamic stochastic general equilibrium model was available that captures two well-known stylized facts: (1) the stagflationary impact of an oil price shock, together with (2) the influence of the energy efficiency of capital on the depth and length of this impact. We build, estimate and simulate a New-Keynesian model with capital accumulation, which takes the case of an economy where oil is imported from abroad, and where these stylized facts can be accounted for. Moreover, the Bayesian estimation of the model on the US economy (1984–2007) suggests that the output elasticity of oil might have been above 10%, stressing the role of oil use in US growth at this time. Finally, our simulations confirm that an increase in energy efficiency significantly attenuates the effects of an oil shock—a possible explanation of why the third oil shock (1999–2008) did not have the same macro-economic impact as the first two ones. These results suggest that oil consumption and energy efficiency have been two major engines for US growth in the last three decades. 相似文献
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2019年,我国成品油消费增速放缓,炼油产能快速扩张使成品油产量增速加快,成品油净出口再创新高;在增储上产政策促动下,国内原油储产量探底回升;受炼油能力增长拉动原油净口量仍较快增长、首次突破5亿t,对外依存度依然维持高位。油气体制改革举措逐步落地,石油市场进一步开放、主体多元化进程加快,油气管网运营机制改革取得标志性进展,同时在调整税费政策、完善油气资源开发利用政策等方面出台了系列规定。新型冠状病毒肺炎疫情对一季度我国成品油需求造成较大影响,但将逐步回复,全年成品油需求预计低速增长,原油产量有望持续回升,炼油能力持续较快增长将推动成品油出口继续增加。 相似文献
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世界油砂资源的研究及开发利用 总被引:3,自引:0,他引:3
油砂是一种重要的非常规石油资源,世界油砂资源折算为油砂稠油约4000×108t,大于天然石油探明储量。世界上最大的油砂矿在加拿大西部的沉积盆地,总储量约占世界储量的50%。委内瑞拉也拥有巨大的油砂稠油资源,其次为俄罗斯和美国等,中国的油砂资源尚未经详细勘察。油砂的结构可以分为亲水性和亲油性两类,亲水性油砂较易将稠油与固体颗粒分开,而亲油性油砂则较难将稠油与固体颗粒分开。油砂开发、稠油提取以及油砂干馏主要有露天开发和稠油提取、油砂干馏、地下就地提取稠油三类工艺。工业上油砂露天开采、经热碱水抽提制取的稠油除了直接出售,也可加工改质制成合成原油或轻质油品出售,加工改质主要有延迟焦化和流化焦化两种工艺流程。目前世界上只有加拿大有大规模的油砂开发和提取稠油及稠油加工工业,阿尔伯达省油砂稠油等油品的总产量达到130×104bbl/d,占加拿大总原油产量的45%,盈利较丰厚。美国有几家公司正在进行美国油砂的抽提研究和中型试验,尚无工业生产。中国石油大学等进行了中国及其他一些国家油砂的抽提和干馏研究;中国石油勘探开发研究院廊坊分院等进行了中国油砂抽提和干馏等研究及中试。中国三大石油公司都涉足加拿大油砂工业的开发利用。 相似文献