共查询到17条相似文献,搜索用时 156 毫秒
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通过小型汽油机台架试验,研究了陶瓷-金属梯度功能材料对内燃机耐久性的影响。实验表明内燃机滑动摩擦零件的表面采用陶瓷-金属梯度功能材料后,可使内燃机的动力性、燃油消耗率和耐久性均得到明显改善。分析表明该梯度功能材料可以显著降低运动件之间的摩擦系数,提高其耐磨性,同时可以提高活塞环与缸套的密封性,从而有效地降低内燃机的摩擦损失和漏气损失。 相似文献
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全国高技术产业化协作组织 ( CHC)推出了“低温下金属基 -陶瓷复合技术”。该技术已获国家专利。它适用于机械、冶金、化工、交通运输、轻工业和航空航天等部门。低温下 (低于 35 0℃ )金属基陶瓷复合技术采用超微粒子等离子体 CVD技术 ,通过薄膜陶瓷与基体金属间发生的相互扩散 ,在金属表面产生一种新型的倾斜梯度功能材料 ,从而提高了金属基体表面的硬度、韧性、耐磨性、耐腐蚀性、抗氧化性 ,并降低表面摩擦系数。它不影响加工件的精度和装配性能 ;加工件不受材质、形状和部位的限制 ;不论受热与否都绝不会发生镀层脱落现象。发动机缸… 相似文献
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秦松祥 《小型内燃机与摩托车》2008,37(3):19-24
为了弄清摩托车发动机加装催化转化器后对发动机功率和油耗的影响情况,利用发动机性能测试台架、发动机转鼓测试系统和工况法排放测试装置对摩托车发动机分别加装常用的几种催化转化器载体--蜂窝式陶瓷载体、金属箔片式蜂窝载体、金属蜂窝式载体以及金属管式载体进行了试验,并与不加装催化转化器的原机进行了对比,结果表明,摩托车发动机加装催化转化器后,在6000r/min以下的中低转速范围内运行时,对发动机功率的影响不大,而油耗还有降低效果;但在高速范围内运行时,会造成功率下降和油耗升高.因此,在选择装催化转化器载体时,应通过试验优选后确定. 相似文献
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针对某型号增压柴油发动机在台架耐久试验过程中,多次出现缸盖与排气歧管结合面漏气问题,从金属凸筋垫片的密封原理角度对失效件进行结构化分析。在问题排查过程中,借助计算机辅助工程(CAE)仿真方法分析密封部件在装配及工作状态下的接触应力,并与FUJI面压试验测试结果进行对比,确定CAE仿真模型的准确性。通过降低排气歧管垫片的表面摩擦系数,以及增加排气歧管双头螺柱长度的方式,实现了排气歧管密封功能的优化。优化后的方案通过了台架耐久试验考核。 相似文献
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劳国强 《柴油机设计与制造》2016,(2)
根据材料构件的疲劳原理、试验方法和发动机耐久运行的失效案例,对现有的发动机耐久模型进行了分析,提出了简化耐久模型和一般耐久模型的概念。应用耐久模型对发动机的耐久考核与无大修工作周期或行驶里程的关系进行了分析,并阐述了耐久与疲劳的关系。 相似文献
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用V—MPC增压系统改善车用柴油机低速性能的研究 总被引:2,自引:0,他引:2
为改善车用涡增压柴油机低速性能,而又不损失高速性能,提出了V-MPC增压系统,并对其进行了理论分析和实验研究。在某涡轮增压柴油机上试验结果表明,采用V-MPC增压系统可改善低速性能。 相似文献
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本文对功能梯度材料的设计、制备、特性评价做了简单介绍,同时研究了金属陶瓷功能梯度材料在内燃机上的应用。实验表明这种新型材料对发动机的动力性,燃油消耗率均有不同程度的改善。初步分析表明,金属陶瓷功能梯度材料所具有的良好的减磨性对发动机功率、扭矩的提高,油耗的下降有重要作用。 相似文献
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针对传统的涡轮箱0-0截面选配方法在发动机性能调试过程中存在的周期长、成本高等问题,利用AVL BOOST发动机性能分析软件建立了不同涡轮箱0-0截面积的某12V150柴油机性能计算模型,分析了涡轮箱0-0截面积对柴油机性能的影响规律,并通过试验进行了验证,为柴油机性能改进奠定了基础。 相似文献
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介绍了四种不同型号的喷油泵在SC9D220柴油机上的油耗及性能对比。通过对不同型号的喷油泵在同一台发动机上做模拟外特性试验,得出不同的性能结果。综合各方面,P7100泵用平顶柱塞效果较好,而且在工程机械上,平顶柱塞比顶隙柱塞使用寿命更具优势。此试验也为D6114系列其他型号柴油机的进一步性能优化提供了参考。 相似文献
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INTRODUCTIoNHeattransferbetweentheworkingmediuminare-ciprocatingengineanditscombustionchamberwallplaysaveryimportantroleintheenginethermalpro-cess.Alargeamountofheatsuppliedbythefuelislosttothecoolantthroughthecombustorwall.Thepercentagerangesfrom1o-25atfullloadto3ty35atlightloadcondition[11.Sincetheconceptofadi-abaticturbocompoundengineswaspresentedin1atel97o's[zl,worldwideattentionhasbeenattractedtotheopportunitiestoimprovethefuelconsumptionbyreducingtheheattransferratesthroughthecom-bus… 相似文献
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利用GT-Power软件建立某机车柴油机仿真计算模型,通过试验验证了仿真模型的准确性。对采用两种米勒循环时该柴油机在1 000r/min不同负荷条件下的功率、油耗和排放影响建立了仿真方案,在全负荷条件下进行了两种米勒循环对比。结果表明,两种方式米勒循环都能显著降低NO_x排放;综合分析柴油机各性能结果,选取变凸轮型线米勒循环、米勒度为30°曲轴转角为提高该机车柴油机性能的优化方案。该方法对机车柴油机应用米勒循环具有一定指导意义。 相似文献
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In this study, performance and emissions of cottonseed oil methyl ester in a diesel engine was experimentally investigated. For the study, cottonseed oil methyl ester (CSOME) was added to diesel fuel, numbered D2, by volume of 5%(B5), 20%(B20), 50%(B50) and 75%(B75) as well as pure CSOME (B100). Fuels were tested in a single cylinder, direct injection, air cooled diesel engine. The effects of CSOME-diesel blends on engine performance and exhaust emissions were examined at various engine speeds and full loaded engine. The effect of B5, B20, B50, B75, B100 and D2 on the engine power, engine torque, bsfc's and exhaust gasses temperature were clarified by the performance tests. The influences of blends on CO, NOx, SO2 and smoke opacity were investigated by emission tests. The experimental results showed that the use of the lower blends (B5) slightly increases the engine torque at medium and higher speeds in compression ignition engines. However, there were no significant differences in performance values of B5, B20 and diesel fuel. Also with the increase of the biodiesel in blends, the exhaust emissions were reduced. The experimental results showed that the lower contents of CSOME in the blends can partially be substituted for the diesel fuel without any modifications in diesel engines. 相似文献
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《International Journal of Hydrogen Energy》2023,48(4):1602-1624
In the present study, Reynolds-Averaged Navier-Stokes simulations together with a novel flamelet generated manifold (FGM) hybrid combustion model incorporating preferential diffusion effects is utilised for the investigation of a hydrogen-blended diesel-hydrogen dual-fuel engine combustion process with high hydrogen energy share. The FGM hybrid combustion model was developed by coupling laminar flamelet databases obtained from diffusion flamelets and premixed flamelets. The model employed three control variables, namely, mixture fraction, reaction progress variable and enthalpy. The preferential diffusion effects were included in the laminar flamelet calculations and in the diffusion terms in the transport equations of the control variables. The resulting model is then validated against an experimental diesel-hydrogen dual-fuel combustion engine. The results show that the FGM hybrid combustion model incorporating preferential diffusion effects in the flame chemistry and transport equations yields better predictions with good accuracy for the in-cylinder characteristics. The inclusion of preferential diffusion effects in the flame chemistry and transport equations was found to predict well several characteristics of the diesel-hydrogen dual-fuel combustion process: 1) ignition delay, 2) start and end of combustion, 3) faster flame propagation and quicker burning rate of hydrogen, 4) high temperature combustion due to highly reactive nature of hydrogen radicals, 5) peak values of the heat release rate due to high temperature combustion of the partially premixed pilot fuel spray with entrained hydrogen/air and then background hydrogen-air premixed mixture. The comparison between diesel-hydrogen dual-fuel combustion and diesel only combustion shows early start of combustion, longer ignition delay time, higher flame temperature and NOx emissions for dual-fuel combustion compared to diesel only combustion. 相似文献