某型柴油机连杆轴瓦异常磨损分析及改进

针对某型柴油机连杆轴瓦多次出现异常磨损,且均为短里程异常磨损的问题,对相关零部件的设计和应用进行分析。分析表明:曲轴连杆颈油孔倒角位置圆角过小及连杆轴瓦工作表面处理方式不当是导致该故障的主要原因。据此给出了改进方案,经台架试验及市场验证,该改进方案有效。     

某型柴油机连杆大端瓦抱轴烧蚀故障原因分析

某型柴油机在台架磨合试验过程中出现连杆大端瓦抱轴、烧蚀故障。基于故障现象,并结合连杆大端瓦润滑原理,从零部件质量、装配质量、试验过程、滑油系统四个方面进行了排查。结果表明:故障的根本原因为曲柄臂油孔内清洁度较差,含有大量金属颗粒与油泥混合物。     

某型柴油机连杆工艺改进研究

针对某型柴油机连杆断裂故障,对连杆小端油孔抗疲劳加工和表面喷丸强化残余应力控制技术进行了研究,并根据研究结果对传统加工工艺进行了改进。工艺改进后的现场试验和小批量试制验证表明:采用新工艺加工的连杆其残余应力控制在合理范围。     

如何确保4102轴瓦产品的形位公差

内燃机滑动轴承(特别是主轴瓦、连杆轴瓦及连杆衬套等)是主要易损件之一,发动机的工作可靠性、强化潜力和使用耐久性等均与轴瓦及衬套的可靠性及其寿命有密切关系,因而作为内燃机关键配件之一的滑动轴承,已越来越受到各方面的重视.4102轴瓦(主轴瓦、连杆瓦)图纸要求形位公差有:(1)轴瓦两对口平面对外圆母线平行度0.02mm.(2)轴瓦油孔中心及油槽中心对瓦宽中心位置度0.5mm(连杆瓦无此项要求).     

内燃机曲轴滑动轴承(轴瓦)设计计算(Ⅱ)

5轴瓦结构要素形状、尺寸、公差5.1油槽5.1.1油槽形状、尺寸、公差主轴瓦的油槽是为向连杆轴承供油而设置的,其宽度和深度尺寸取决于供油量,并与轴颈油孔尺寸有关。两种油槽形状、尺寸与极限公差应符合GB/T3162-91规定,参照表30和表31。     

轴瓦油槽切向收尾的加工方法

国内外大多数中、大功率的柴油机滑动轴承,其结构设计在受力瓦(主轴瓦为下瓦、连杆瓦为上瓦)和非受力瓦上开半圆或一定角度弧长的油槽。并将油槽收尾处设计成与轴瓦内圆相切向收尾的形式。(如图1)所示为 PA6V280连杆上瓦结构图。这种设计润滑油经油槽流入轴承内表面与轴颈间的间隙处将是连续,平稳地,有利于油膜的建立和形成,不会因自然收尾所形成的棱角凸峰使其油道截面的突变。引起润滑油流动的不平稳波动。产生紊流以及瞬时低压构成气泡,造成气蚀现象,破坏油膜的形成。造成临界摩擦,严重时将导致熔焊而抱轴。     

L42MC机轴瓦通过MAN B＆W公司700小时装机试验

3月底，从丹麦MANB＆W柴油机公司传来消息，中国船舶重工集团公司直属大型企业，专业从事大、中功率船用内燃机零部件研发和生产的重庆跃进机械厂按照该公司最新标准研制生产的L42MC型低速柴油机连杆瓦，已经通过该公司派出的监督工程师在美国上船进行的700小时装机试验检测。拆机检测结果认为，重庆跃进机械厂生产的L42MC型低速柴油机连杆瓦上下瓦状况良好，可以继续装机试验，直至完成3000小时装机试验获得最终认证。同时，通过双方的努力，重庆跃进机械厂生产的70MC主轴瓦和连杆瓦的装机试验也已经开始。这标志着跃进厂在获得成为丹麦MAN B＆W柴油机公司低速柴油机轴瓦的供应商方面迈出了重要的一步。     

重庆跃进机械厂42MC机轴瓦通过MAN B&W柴油机公司700小时装机试验

3月底,从丹麦M A N B&W柴油机公司传来消息,中国船舶重工集团公司直属大型企业,专业从事大、中功率船用内燃机零部件研发和生产的重庆跃进机械厂按照该公司最新标准研制生产的L 42M C型低速柴油机连杆瓦,已经通过该公司派出的监督工程师师在美国上船进行的700小时装机试验检测。拆机检测结果认为,重庆跃进机械厂生产的L42M C型低速柴油机连杆瓦上下瓦状况良好,可以继续装机试验,直至完成3000小时装机试验获得最终认证。同时,通过双方的努力,重庆跃进机械厂生产的70M C主轴瓦和连杆瓦的装机试验也已经开始。这标志着跃进厂在获成为丹麦…     

浅谈某柴油机连杆瓦烧瓦原因分析

我们基于某型柴油机连杆瓦烧瓦问题,针对曲轴的制造质量、润滑油压力及润滑系统、连杆刚性、配瓦间隙及连杆瓦自身参数等方面进行分析,结果表明:连杆瓦自身参数半径高偏大是导致连杆瓦烧瓦的主要原因。同时,通过优化半径高,并进行有关的试验验证,成功解决了连杆瓦烧瓦问题。     

DF_7型机车柴油机连杆瓦失效故障分析与预防

针对DF7型机车柴油机发生多起连杆瓦失效,柴油机遭受重大损失的故障,搜集该机型连杆瓦故障信息并进行分析。分析表明:轴瓦失效的主要形式是微动磨损引起的磨损失效;分析了轴瓦产生微动磨损的主要原因,并提出了预防措施。     

美国战略石油储备补仓和释放策略分析

美国是最早建立战略石油储备的国家之一,自20世纪70年代开始已逐步形成了一套比较完善的战略石油储备决策管理体系。历史数据表明,美国战略石油储备的几次释放和补仓时机都把握得很好,充分发挥了战略石油储备保障国家石油供应安全、平抑国际原油价格的作用。本文系统地介绍和分析了美国战略石油储备几次主要的释放和补仓策略,以期为探讨我国战略石油储备的补仓和释放时机与策略,提供决策信息参考。     

开发难动用储量保障国家石油安全

保障我国石油安全有多种措施：建立石油储备、发展替代能源、降低能耗、从国外获取稳定的石油供应、加大国内石油资源的勘探开发力度等。其中，加强国内石油资源的勘探开发是最重要的途径。本文针对我国陆上近４０亿ｔ已探明难动用石油地质储量的现实，从国家石油政策、技术进步、开发方式和机制、评价方法和参数等方面论述了促进难动用储量开发，保障国家石油安全的途径。     

Mitigation of maximum world oil production: Shortage scenarios

A framework is developed for planning the mitigation of the oil shortages that will be caused by world oil production reaching a maximum and going into decline. To estimate potential economic impacts, a reasonable relationship between percent decline in world oil supply and percent decline in world GDP was determined to be roughly 1:1. As a limiting case for decline rates, giant fields were examined. Actual oil production from Europe and North America indicated significant periods of relatively flat oil production (plateaus). However, before entering its plateau period, North American oil production went through a sharp peak and steep decline. Examination of a number of future world oil production forecasts showed multi-year rollover/roll-down periods, which represent pseudoplateaus. Consideration of resource nationalism posits an Oil Exporter Withholding Scenario, which could potentially overwhelm all other considerations. Three scenarios for mitigation planning resulted from this analysis: (1) A Best Case, where maximum world oil production is followed by a multi-year plateau before the onset of a monatomic decline rate of 2–5% per year; (2) A Middling Case, where world oil production reaches a maximum, after which it drops into a long-term, 2–5% monotonic annual decline; and finally (3) A Worst Case, where the sharp peak of the Middling Case is degraded by oil exporter withholding, leading to world oil shortages growing potentially more rapidly than 2–5% per year, creating the most dire world economic impacts.     

我国经济和社会发展中必须重视石油峰值问题

石油峰值(Peak Oil)是指某一区域(全球、地区、国家、油区等)石油产量的最大值及其来临的时间。世界石油产量到达峰值并不意味着全世界已将石油消耗怠尽,也不意味着人类不可能在地球上再发现新的油田,只是新发现的油田的石油产量越来越无法弥补已开发油田产量的下降,世界石油供应量不可能再增加,不能满足人类日益增长的需求。许多研究表明世界石油产量正在进入峰值平台期,随时都可能出现资源长期短缺的石油危机。我国的石油消费一直以较快的速度增长,石油也许很快成为我国经济发展的瓶颈。本文提出了石油峰值——我国经济和社会发展中必须重视的一个重大问题,希望大家尤其是主管部门和高层决策者充分认识石油峰值的内涵和挑战,高度重视我国面临的潜在的石油危机,认真落实科学发展观、未雨绸缪,提早采取应对策略以实现我国经济社会的可持续发展。     

Feasibility of edible oil vs. non-edible oil vs. waste edible oil as biodiesel feedstock

Biodiesel has high potential as a new and renewable energy source in the future, as a substitution fuel for petroleum-derived diesel and can be used in existing diesel engine without modification. Currently, more than 95% of the world biodiesel is produced from edible oil which is easily available on large scale from the agricultural industry. However, continuous and large-scale production of biodiesel from edible oil without proper planning may cause negative impact to the world, such as depletion of food supply leading to economic imbalance. A possible solution to overcome this problem is to use non-edible oil or waste edible oil (WEO). In this context, the next question that comes in mind would be if the use of non-edible oil overcomes the short-comings of using edible oil. Apart from that, if WEO were to be used, is it sufficient to meet the demand of biodiesel. All these issues will be addressed in this paper by discussing the advantages and disadvantages of using edible oil vs. non-edible vs. WEO as feedstock for biodiesel production. The discussion will cover various aspects ranging from oil composition, oil yield, economics, cultivation requirements, land availability and also the resources availability. Finally, a proposed solution will be presented.     

对燃油锅炉渣油供油系统的工艺改进

针对渣油特性及其应用过程中易发生的问题,介绍了供油系统的几项有效改进措施。     

Factors Affecting the Oil Agglomeration of Sivas-Divriği Uluçayır Lignite

Abstract

In the coal industry, the coal particles need to be decreased to a very fine size because of the need of removing inorganic materials from coal. Oil agglomeration is a kind of coal cleaning technique that is used for separation of organic and inorganic parts of fine sized coal. In this study, the oil agglomeration of Sivas-Divri?i (S-D) Uluçay?r lignite was carried out by using kerosene, diesel oil, fuel oil, poppy oil, and sunflower oil. The amount of bridging oil was varied from 5% to 25% of the amount of lignite. The effect of oil amount, oil type, solid content, agitation rate and time, pH on agglomeration performance was investigated. Maximum recovery value of 98.18% was observed by using poppy oil. In order to investigate the effect of pH on agglomeration NaOH and HCl is added to the slurry in various amounts. It is decided that the best agglomeration condition is obtained at low pH values. The effect of nonionic surface active agent (Igepal-CA 630) on agglomeration is investigated by adding to the slurry and it is observed that the grade is increased with the amount of surface active agent.     

我国急需发展石油期货市场

本文从我国石油需求逐年上升、对进口依赖性不断提高以及国际石油市场起伏不定的现实出发,分析论述了我国发展石油期货市场的必要性和可行性,并提出了发展石油期货市场方面的建议。     

关于润滑油衰变原因与危害的探讨

从润滑油衰变的因素、危害等方面讨论了润滑油的变质对机械设备的影响。     

The production of fuel from,and the thermal stability of,sunflower oil,corn oil,and canola oil

Frying of sunflower, corn, and canola oils was carried out for seven running days at 175°C in this study. Fatty acid composition, free fatty acid, viscosity, iodine value, peroxide value, density, pH, saponification value, refractive index, average molecular weight, color, and the higher heating value of these oils have been analyzed. While the contents of free fatty acid, viscosity, saponification value, peroxide value, and colors (red and yellow) increase with the frying times, the contents of average molecular weight, iodine value, pH, and the higher heating value decreased for all oils in this work. However, reduction in the higher heating value is relatively low. This work indicated that recycling as a fuel of these oils can make a major economic contribution.