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《内燃机与动力装置》2020年第3期

作者:  发布时间:2020-06-30   浏览次数:

 

水蒸气对火焰特性和碳烟生成影响的数值模拟

郑宇恒,邱亮,孟顺,庄远,钱叶剑

合肥工业大学 汽车与交通工程学院, 安徽 合肥 230009

要:在协流空气中添加不同的虚拟组分,基于完全解耦法数值模拟研究常压条件下乙醇/空气同轴层流扩散火焰中水蒸气对火焰特性和碳烟生成的影响。研究结果显示加入水蒸气后,火焰的峰值温度和最大碳烟体积分数均降低;水蒸气通过稀释效应、化学效应、热力学效应和辐射效应影响火焰特性和碳烟生成,其中化学效应和稀释效应占主导地位;水蒸气的化学效应会改变O、H、H2OH等组分的摩尔分数,OH浓度的增加促进了碳烟的氧化。水蒸气的化学效应也会影响苯(A1)、苾(A4)、炔丙基(C3H3乙炔(C2H2等碳烟生成中间产物的摩尔分数,降低了碳烟核心的成核速率和表面增长速率。

关键词:乙醇;同轴层流扩散火焰;水蒸气碳烟生成;化学效应

Numerical analysis of effects of water vapor addition on the flame properties and Soot formation in ethanol coflow flame

ZHENG Yuheng, QIU Liang, Meng Shun, ZHUANG Yuan, QIAN Yejian

School of Automotive and Transportation Engineering, Hefei University of Technology, Hefei 230009, China

Abstract: Based on the complete decoupling method, different virtual components are added to the coflow air, the effects of water vapor on the flame properties and soot formation characteristics in an ethanol/air coflow laminar diffusion flame at atmospheric pressure were investigated with numerical simulation. The results show that, with the blending of water vapor, the peak temperature of the flame and the maximum soot volume fraction reduce. The water vapor influence flame properties and soot formation through dilution effect, chemical effect, thermal effect and radiation effect. The chemical effect and dilution effect play dominate roles. The chemical effect affects the O, H, H2 and OH radicals mole fraction, and the increase of OH radical enhance the oxidation of soot. The chemical effect also influences the intermediates of soot formation, such as benzene (A1), pyrene (A4), C3H3 and acetylene (C2H2), then reduce the rate of soot nucleation and surface growth.

Keywords: ethanol; coflow laminar diffusion flame; water vapor; soot formation; chemical effect

装载机热管理仿真与试验研究

吴承鑫1,张寒杉1,祝成祥2,3,郑玉杰2,3

1.龙工(上海)机械制造有限公司,上海 201612;2.内燃机可靠性国家重点实验室,山东 潍坊 261061

3.潍柴动力股份有限公司 应用工程中心,山东 潍坊 261061

摘要:通过一维/三维耦合仿真方法进行装载机热管理仿真计算,建立装载机整车三维模型,利用Fluent商业软件,计算发动机舱内的空气流动。计算结果表明:散热器进风不均匀,散热器上部与下部形成热风回流,整机左右两侧进风口的进风不畅和风扇周围形成多处涡流;利用三维仿真得到的散热器进口风量,在一维仿真中反推机舱阻力系数,利用KULI软件,计算发动机出水温度、液压油散热器进口温度、传动油散热器进口温度;通过仿真数据与试验数据的对比,验证了一维/三维耦合仿真的准确性。

关键词:装载机;耦合;仿真;试验

Simulation and experimental study of loader thermal management

WU Chengxin1, ZHANG Hanshan1, ZHU Chengxiang2,3,ZHENG Yujie2,3

1.Longgong (Shanghai) Machinery Manufacturing Co., Ltd., Shanghai 2011612China2. The State Key Laboratory of Reliability of Engine, Weifang 261061China3. Weichai Power Co., Ltd, Weifang 261061China

AbstractThe three-dimensional model of the whole loader is firstly established, and the commercial software Fluent is used to calculate the air flow in the engine compartment. The calculation results show that the air inlet of the radiator is not uniform, the hot air backflow is formed in the upper and lower part of the radiator, the air inlet on the left and right sides of the whole machine is poor, and many vortices are formed around the fan. Then, the inlet air flow of the radiator is obtained through the three-dimensional simulation, the engine room resistance coefficient is pushed back in one dimension, and the outlet water temperature of the engine, the inlet temperature of hydraulic oil and the inlet temperature of transmission oil are calculated by Kuli commercial software. Finally, experimental data are compared to verify the accuracy of one-dimensional/three-dimensional coupling simulation.

Key wordsloader, coupling, simulation,test

 

内燃机活塞环组摩擦力测试系统的开发

才骐铭,刘勇强,滕勤

合肥工业大学 汽车与交通工程学院安徽合肥 230009

摘要针对浮动缸套装置,构建以拉压传感器、电荷放大器、增量式编码器、采集卡和工控机等组成的活塞环组摩擦力测试系统的硬件系统,借助LabVIEW语言开发具有状态参数配置、数据样本采集、数据处理、数据存储和数据回放等功能的软件系统。试验结果表明,该系统能够获得发动机工作时缸套-活塞环组摩擦力与曲轴转角的准确关系,可以为分析不同活塞环组特性对发动机摩擦损失的影响和设计低摩擦活塞环组提供所需的数据依据。

关键词:活塞环组摩擦力;浮动缸套法;测量系统;同步数据采集

Development of piston ring assembly friction test system

CAI QiMing, LIU YongQiang, TENG Qin

School of Mechanical and Automotive Engineering, Hefei University of Technology, Hefei  230009, China

Abstract: In order to provide the data basis for the design of piston and ring assembly with low-friction, a hardware system for the piston ring assembly friction test system was constructed based on the floating liner device. The hardware system consists of sensor, charge amplifier, incremental encoder, acquisition board and industrial computer. The software system was developed with LabVIEW, which has the functions of state parameter configuration, data acquisition, data processing, data storage and data playback. The experimental results show that the system can accurately obtain the relationship between the piston ring assembly friction and crankshaft rotation angle during engine operation, which provides data for analyzing the influence of different piston and ring assembly characteristics on the friction loss of the engine.

Key words:piston ring assembly friction; floating liner method; test system; synchronous data acquisition

轨压和喷油提前角对柴油机排放影响的试验研究

王刚,赵福芹,李同楠

潍柴重机股份有限公司,山东 潍坊 261000

摘要以自吸式4缸直喷电控高压共轨柴油机为例,试验研究柴油机排放中NOx和颗粒物随轨压和喷油提前角的变化规律。结果表明:一定喷油提前角范围内,NOx排放随着轨压的增大而升高,烟度随着轨压的增大降低;喷油提前角大于一定值时,NOx排放与烟度受轨压影响较小;选择适当的喷油提前角并调整轨压能够有效降低NOx排放及颗粒物排放,使柴油机满足排放要求;排放污染物中HC占比很小,主要控制NOx排放即可。

关键词高压共轨技术;轨压;喷油喷油提前角;NOx排放;烟度;预喷

Experimental study on the effects of rail pressure and fuel injection advance angle on emissions

WANG GangZHAO Fuqin, LI Tongnan

Weichai Heavy Machinery Co., Ltd., Weifang, Shandong 261000

Abstract: Taking a natural inspiration four cylinder direct injection electronically controlled high-pressure common rail diesel engine as an example, the variation of NOx emissions and particles with rail pressure, injection advance angle and pre-injection was explored. The results show that the emission of NOx increases with the increase of rail pressure, and the emission decreases. When the advance angle is greater than a certain value, the NOx emission and smoke pressure are less affected by the rail pressure. Choosing the appropriate injection advance angle and adjusting the rail pressure can effectively reduce NOx emissions and particles, so that the diesel engine can meet the emission requirements. The proportion of hydrocarbon is very small, the main control of NOx is enough.

Key words: high-pressure common rail technology; rail pressure; injection advance angle; NOx emission; smoke; pre-injection

 

弯管进气对离心压气机效率的影响

李聪1,白书战1,李延昭2,3,张健健2,张金明2

1. 山东大学 能源与动力工程学院,山东 济南 250061;2. 康跃科技股份有限公司,山东 潍坊 262718;3. 机械工业内燃机增压系统重点试验室,山东 潍坊 262718

摘要:对弯管进气的离心压气机进行数值模拟计算,通过直管进气试验和数值模拟结果的对比分析,研究弯管对离心压气机效率的影响,分析在3种不同形式的弯管进气条件下压气机效率的变化。研究结果表明:弯管进气时压气机效率会有所降低,不同形式的弯管进气对压气机效率的影响不同。在恒定转速小流量工况下弯管与直管进气压气机效率相差较小,随着流量的增加,弯管进气直管进气压气机效率差值逐渐增大;当转速不同时,弯管进气造成叶轮进口严重的气流不均匀流动,使效率下降,高速大流量情况效率下降最为明显,其中普通90°弯管进气效率最高下降可达7%。

关键词:弯管进气;离心压气机;数值模拟;效率

Effect of curved pipe intake on centrifugal compressor efficiency

LI Cong1, BAI Shuzhan1, LI Yanzhao2,3, ZHANG Jianjian2, ZHANG Jinming2

1. School of Energy and Power Engineering, Shandong University, Jinan 250061, China; 2. Kangyue Technology Co., Ltd., Weifang 262718, China;3. Key Laboratory of Internal Combustion Engine Pressurization System in Machinery Industry, Weifang 262718, China

Abstract: In this paper, the numerical simulation of centrifugal compressors with curved inlets is performed. At the same time, the effects of curved tubes on the efficiency of centrifugal compressors are studied by comparing and analyzing with the results of experimental and numerical simulations of straight tube inlets. The results of numerical simulation show that the compressor efficiency will decrease when the inlet of the curved tube is different, different forms of curved intake tubes have different effects on compressor efficiency. At a constant speed, the efficiency difference is quite little between the curved tube and straight tube intake. As the flow rate increases, the efficiency of the compressor gradually decreases compared to the straight tube inlet difference. The curved pipe inlet causes serious uneven airflow at the impeller inlet, which reduces the efficiency. The efficiency drop is highest in the case of high-speed and large flow. The maximum drop in the efficiency of ordinary 90°curved tube intake can reach 7%.

Keywords: curved pipe; centrifugal compressor; numerical simulation; efficiency

乘用车涡轮增压器噪声改善装置设计

桑梧海,刘永芳,苏益龙,司英杰

康跃科技股份有限公司,山东 寿光 262718

摘要:为了降低涡轮增压器滞后于发动机运转产生的尾音,设计一种用于改善乘用车增压器噪声的气流切换装置。该装置安装一个与油门传动连接的转换阀,控制旁通管、压气机出气管和发动机进气管管路连通状态。油门松开时,转换阀控制旁通管与压气机出气管和发动机进气管之间管路的交替启闭,降低涡轮增压器的尾音、缩短尾音时长。试验验证表明,设计的噪声改善装置可以降低涡轮增压器最高转速,而且降速平缓,能够有效降低尾音、改善噪声。

关键词:涡轮增压器噪声乘用车

Design of noise improvement device for turbocharger of passenger car

SANG Wuhai,LIU Yongfang,SU Yilong,Si Yingjie

Kangyue Technology Co., Ltd. ,Shouguang 262718, China

Abstract: In order to solve the tail noise caused by the turbocharger lagging during the engine operation, this paper invented an airflow switching device for improving the noise of a passenger car turbocharger. The device includes a connection to the throttle and can control the bypass pipe. The switching valve that is opened and closed alternately with the pipeline between the compressor outlet pipe and the engine intake pipe. With the release of the throttle, the switching valve is driven to control the alternate opening of the pipeline between the bypass pipe and the compressor outlet pipe and the engine intake pipe. After experimental test verification, the maximum speed of the turbocharger can be reduced, and the speed reduction phase is relatively gentle, effectively reducing the tail sound and improving noise.

Keywords: turbocharger;noise;passenger car

柴油机电动压气机模拟分析

张广西1,2,史玉梅1,2,周文彦1,2,杨豫魁1,2

1.内燃机可靠性国家重点实验室,山东 潍坊 261061;2.潍柴动力股份有限公司,山东 潍坊 261061

摘要:某款4缸轻型柴油机电动压气机对发动机性能的影响进行仿真分析,研究电动压气机对发动机瞬态工况改善情况。匹配研究表明:电动压气机布置在压气机出口,与普通增压器串联,能够有效改善发动机某些工况的动力性和瞬态响应特性,发动机转速越低,改善效果越明显。转速为1300 r/min时,扭矩提升7.23%,定速加负荷工况的加速时间从16.7 s缩短至6.7 s,减少了60%;转速为1400 r/min时,扭矩提升6.52%,定速加负荷工况的加速时间从16.1 s缩短至7.1 s,减少了56%。

关键词:电动压气机;性能;瞬态响应特性;净功率

Simulation Analysis on Electric Compressor of Diesel Engine

ZHANG Guangxi1,2 , SHI Yumei1,2,ZHOU Wenyan1,2,YANG Yukui1,2

1.State Key Laboratory of Engine Reliability, Weifang 261061, China; 2. Weichai Power Co., Ltd., Weifang 261061, China

Abstract: Basing on a certain type of 4-cylinder light-duty diesel engine, the influence of electric compressor on engine performance is simulated and analyzed, meanwhile, the transient working condition improvement by electric compressor is also studied. The research shows that the electric compressor arranged at the outlet of the compressor, parallel with turbocharger, could effectively improve the dynamic performance and transient response characteristics of the engine under certain conditions. The lower the engine speed, the higher the improvement. For instance, at the speed of 1300r/min, the torque could be increased by 7.23%, under constant speed loading conditions, the maximum acceleration time can be reduced from 16.7s to 6.7s, and reduces by 60%. At the speed of 1400r/min, the torque could be increased by 6.52%, under constant speed loading conditions, the maximum acceleration time can be reduced from 16.1s to 7.1s, and reduces by 56%.

Key words: electric compressor; performance; transient response characteristics; net power

基于动力学分析的柴油机铝活塞摩擦磨损优化

孙琛媛1,2,刘召伟1,2,宋树峰1,2,郭庆元1,2

1.滨州渤海活塞有限公司,山东 滨州 256602;

2.山东省发动机活塞摩擦副重点实验室,山东 滨州 256602

摘要为了降低某柴油机铝活塞降低摩擦磨损,在不更改活塞刚性的基础上,通过优化销孔偏置设计、降低活塞环高度、更改裙部型面等措施对活塞进行优化改进。利用动力学分析软件对优化前后活塞进行对比,模拟结果显示活塞的机油耗和漏气量明显降低,敲击动能和摩擦平均有效压力降低。通过倒拖法和可靠性试验验证改进措施的有效性。结果表明:销孔向主推力侧偏置0.5 mm,配合减小活塞环环槽宽度、优化裙部形线时,活塞摩擦平均有效压力最小,可以有效降低活塞的摩擦磨损。

关键词:活塞;摩擦磨损;有限元分析;动力学分析

Friction and wear optimization of aluminium piston of a diesel engine based on dynamics analysis

SUN Chenyuan1,2,LIU Zhaowei1,2, SONG Shufeng1,2,GUO Qingyuan1,2

1. Binzhou Bohai Piston Co., Ltd., Binzhou 256602, China; 2. Shandong Province Key Laboratory of Engine Piston Cylinder Kits, Binzhou 256602, China

Abstract: In order to reduce the friction and wear of a diesel engine piston without changing its stiffness, improvements have been conducted including optimizing pin bore offset, lowering ringsheights, optimizing side profile. Dynamics analysis was used for comparison of piston proposals before and after these optimization. The simulated results show that the oil consumption, blow by, knocking energy and average friction pressure have been reduced, which have been verified by dynometer test and reliability test. It could be found that the average friction pressure is the lowest when offset of pin bore is 0.5mm to thrust side, with ring groove width reduced and side profile optimized, which can eventually reduce the pistons friction and wear.

Key words: Piston; Frictional and wear; Finite element analysis; Dynamics analysis

酸、碱性溶液浸泡对柴油机催化剂性能的影响

刘兴龙1,2,霍翠英1,2,王奉双1,2,郑碧莹1,2,李昭阳1,2

1.内燃机可靠性国家重点实验室,山东潍坊 261061;
2.潍柴动力空气净化科技有限公司,山东潍坊 261061

摘要:以车用柴油氧化催化器(diesel oxidation catalyst, DOC)/涂覆式颗粒捕集器(coated diesel particulate filter, DPF)/选择性催化还原selective catalytic reduction, SCR)为对象,研究酸、碱性溶液对各种柴油机后处理装置催化剂性能的影响。研究表明,DOC和DPF催化剂经酸、碱性溶液处理后性能无明显改变,SCR催化剂经酸性溶液处理后性能无明显改变,但经碱性溶液处理后低温转化效率及氨存储明显下降,SCR入口温度为180时催化剂转化效率下降6.8%,入口温度为250 ℃时氨存储降低了4.5%。

关键词:催化剂;柴油机后处理;酸碱溶液浸泡

Effects of acid and alkaline solution immersion on the performance of diesel engine catalyst

LIU Xinglong1,2, HUO Cuiying1,2, WANG Fengshuang1,2, ZHENG Biying1,2, LI Zhaoyang1,2

1.State Key Laboratory of Engine Reliability, Weifang 261061,China;2.Weichai Power Emission Solutions Technology, Weifang 261061,China

Abstract: In this paper, the effects of acidic solution and alkaline solution on the performance of vehicle diesel engine DOC/DPF/SCR catalysts were studied. It was found that the properties of DOC catalyst and DPF catalyst were not significantly changed after treatment with acidic solution and alkaline solution, the properties of SCR catalyst were not significantly changed after treatment with acidic solution, but the low temperature conversion efficiency and ammonia storage were significantly decreased after treatment with alkaline solution, the conversion efficiency of SCR catalyst decreased by 6.8% when the inlet temperature of SCR was 180 , and ammonia storage decreased by 4.5% when the inlet temperature of SCR was 250.

Keyword: catalyst; diesel engine post-treatment; acid and alkaline soaking.

高强化柴油机铝活塞销孔失效分析

王星全1,2, 1,2, 王占宜1,2, 1,2 , 丁文开1,2

1.滨州渤海活塞有限公司,山东 滨州 256602;

2. 山东省发动机活塞摩擦副重点实验室,山东 滨州 256602

要:针对某缸径为135 mm的高强化柴油机铝活塞销孔出现的异常磨损和开裂现象,综合分析活塞尺寸和探伤检测结果及材料检测结果等,结合活塞销孔失效机理,判定显微缩松是导致此次活塞销孔失效的根本原因,并对活塞铸造工艺进行优化改进对优化后的活塞进行可靠性试验和小批量生产验证,活塞销孔没有出现失效故障,改进方案有效。

关键词:铝活塞;销孔;失效;显微缩松;金相组织

Failure Analysis on Pin Hole of Enhanced Diesel Engine

WANG Xingquan1,2LIU Tao1,2WANG Zhanyi1,2XU Tao1,2DING Wenkai1,2

1.Binzhou Bohai Piston Co., Ltd.Shandong, Binzhou 256602, China;2.Shaodong Province Key Laboratory of Engine Piston Cylinder Kites, Shandong, Binzhou 256602, China

AbstractIn view of the abnormal wear and cracking of the aluminum piston pin hole of a 135mm high strength diesel engine, through the comprehensive analysis including the piston design and test results, the comparison between the failed piston and the normal piston. It is determined that the micro shrinkage is the main cause of the failure of the piston pin hole. Based on this conclusion, the piston casting process was optimized and improved. The optimized piston could pass all the tests of diesel engine.

Key wordsaluminum piston; pin hole; failure; micro-shrinkage; microstructure

基于双闭环的AMT车辆坡道起步控制

李永昌1,2,王飞1,2,李丕茂1,2

1.内燃机可靠性国家重点实验室,山东 潍坊 261061;

2.潍柴动力股份有限公司 发动机研究院,山东 潍坊 261061

摘要:为解决电控机械式自动变速箱(automatic mechanical transmission,AMT)量产过程中面临的坡道起步控制难题,对坡道起步过程坡道起步过程评价指标进行分析,提出将离合器接合速度与发动机转速下降率、变速箱输入轴转速上升率进行双闭环控制的坡道起步控制策略,防止起步过快造成的发动机熄火。在不同坡度上多次进行试验验证,结果表明:在没有坡道起步辅助系统功能时,本文中所提出的控制策略能够很好地满足AMT重卡在不同坡道上的起步要求。

关键词:AMT;坡道起步;转速控制;离合器慢合;离合器控制

Ramp start control of AMT for heavy truck based on double closed loop

LI Yongchang1,2 , WANG Fei1,2 , LI Pimao1,2

1.State Key Laboratory of Engine Reliability, Weifang  261061 , China;2. R&D Center, Weichai Power Co.,Ltd, Weifang 261061, China

AbstractAMT has become an important direction for heavy duty trucks, however the ramp start control is problem of starting control. In order to prevent the engine stop during the ramp start, a closed-loop control strategy is developed, in which the decline rate of the engine speed and the rise rate of transmission input shaft speed are chosen for clutch control, based on the force analysis and evaluation index of ramp start process of vehicle. The experiment results show that the proposed control strategy is feasible without the ramp start assistance system.

Key wordsautomatic manual transmission; hill start; speed control; clutch slow engage; clutch control

燃气发动机阀顶架导杆断裂原因分析

梁杰辉,王彬,张士越

淄博淄柴新能源有限公司,山东 淄博,255000

摘要:针对某大型炼化尾气发电站内多台燃气发动机阀顶架导杆出现的断裂故障,分析导杆材料、强度、热处理工艺、装配工艺等,发现导致导杆断裂的主要原因为疲劳强度不足和装配工艺不规范。对导杆进行氮化处理,提高疲劳强度,进一步规范装配工艺,有效解决了导杆断裂问题。实际应用结果表明:表面氮化处理和规范装配工艺对轴类零件的可靠性至关重要。

关键词:燃气发动机;阀顶架导杆;断裂故障;表面氮化处理;规范装配工艺;轴类零件

Analysis on the guide rod of valves top frame of gas engine

LIANG JiehuiWANG BinZHANG Shiyue

Zibo Zichai New Energy CO., Ltd, Zibo 255000China

Abstract:In a large refinery tail gas power station, fracture on guide rod of valves top frame was reported for several gas engines. This article analyzed the fracture on the guide rod of valves top frame, including the guide bar materials, strength, heat treatment process, assembly process in detail, and found that the main cause of the fracture of fatigue strength is insufficient and the assembly process is nonstandard. The guide bar was strengthened by nitriding treatment and the assembly was improved, which effectively solve the problem of guide rod fracture. It is shown that the surface nitriding treatment and improved assembly process are very important for the reliability of shaft parts.

Keywords:gas engineguide rod of valves top framefracturesurface nitriding treatmentstandard assembly processshaft parts

某客车噪声故障分析及优化

李秀山1,2,李彤1,2,丁保安1,2,张伟龙1,2,梁昌水1,2

1.内燃机可靠性国家重点实验室,山东 潍坊261061;

2.潍柴动力股份有限公司,山东 潍坊261061

摘要:针对某客车的噪声异常问题,通过试验方法,查找并确定故障源,分析故障产生机理并进行优化噪声异常客车驾驶室存在怠速拍频,原因为空气压缩机1.12阶次与发动机曲轴1.00阶次能量干涉,导致振动、噪声异常、舒适度降低;整车室内存在显著打鼓声,原因为进气系统设计不合理及空压机激励大,导致的进气系统声腔共振。通过更换离合器降低1.00阶次异常振动,消除了室内拍频问题; 通过增加进气消音器,降低了激励源的能量,从而消除了打鼓声。优化后进行试验验证,整车噪声、振动、声振粗糙度(noisevibrationharshness,NVH)水平得到明显提升,主观感受整车舒适性得到极大改善,对同类NVH问题的解决提供了参考。

关键词LMS Test.lab;柴油机;NVH;拍频;打鼓声;空气压缩机

Noise analysis and optimization for a bus

LI Xiushan1,2LI Tong1,2DING Baoan1,2ZHANG Weilong1,2LIANG Changshui1,2

1. State Key Laboratory of Engine Reliability, Weifang 261061,China; 2. Weichai Power Co., Ltd., Weifang 261061,China

Abstract: This paper investigates the abnormal noise of a bus. Indoor idle beat frequency is analyzed as energy interference of 1.12 harmonic frequency of air compressor and 1 harmonic frequency of engine crankshaft, which leads to abnormal vibration and noise and makes people feel uncomfortable. There is a significant drummingsound inside the vehicle. The analysis shows that the sound cavity resonance of the air intake system is caused by unreasonable design of the air intake system and large excitation of the air compressor. The indoor beat frequency problem is eliminated by replacing the clutch to reduce 1 order abnormal vibration, and the energy of an excitation source is reduced by adding an air intake silencer. After optimization, the test shows that the NVH level of the vehicle is obviously improved and the subjective comfort of the vehicle is greatly improved, which provides a reference for the solution of similar NVH problems.

Key words: LMS Test.lab; diesel engine; NVH; beat frequency; drumming; air compressor

 

 

凸轮表面剥落原因分析

辛延君2 王超2,姜爱龙1,2

1.内燃机可靠性国家重点实验室,山东 潍坊 261061; 2. 潍柴动力股份有限公司,山东 潍坊 261061

摘要:为解决某船用发动机耐久试验中凸轮表面出现裂纹和材料剥落的问题,通过宏观形貌观察、金相分析及硬度检测等对凸轮进行失效分析,确认凸轮表面失效模式为接触疲劳失效,主要原因为凸轮在加工过程中磨削量太大,经磨削液冷却造成表面二次淬火,耐久试验中在长期较高的接触应力作用下,引起凸轮表面压碎,表层金属材料剥落。优化凸轮精磨过程中的磨削参数,降低磨削速度和径向进给量,再次耐久试验,凸轮表面完好。通过本文分析,确定凸轮表面剥落产生的原因,对凸轮轴产品质量的提升具有参考价值。

Analysis for cam surface cracks

XIN Yanjun2WANG Chao2JIANG Ailong1,2

1.State Key Laboratory of Engine Reliability, Weifang 261061,China; 2.Weichai Power Co.Ltd., Weifang 261061,China

AbstractIn order to solve the cam surface crack problem for a marine diesel, macro analysis such as observation, metallographic analysis and hardness test failure analysis was carried out on. Test results show that the failure modeof cam surface is contact fatigue, which is mainly caused by large grinding amount during the machining process. The surface is cooled by grinding liquid which brings secondary hardening. The cam surface is crushed by the effect of long-term high contact stress during endurance test process. Then the grinding parameters are refined and new cam performs quite well in the test. The analysis of the cam surface crack is of great significance to the promotion of the camshaft product quality, which could improve the service life of the camshaft and the service life of the engine.

Key Wordscamcontact fatiguesecondary quenchingmaterial peeling off

燃料电池公交车暖风系统对续航里程的影响

张安文1,赵强2,3,刘焕东2,3,李慧君2,3

1. 潍坊公共交通总公司,山东 潍坊 261061

2. 内燃机可靠性国家重点实验室,山东 潍坊 261061;3. 潍柴动力股份有限公司,山东 潍坊 261061

摘要:针对燃料电池汽车在寒冷地区续航里程低的问题,分析客车的采暖需求,以寒冷地区运营的大型高三级客车为例,计算有无暖风条件下的整车续航里程变化。计算结果显示,在寒冷地区运营的燃料电池客车,由于暖风能耗的影响,整车续驶里程下降约37%。综合考虑管理散热、热交换效率等因素,燃料电池公交车适合直接使用电热供暖,提升燃料电池的使用效率。

关键词:燃料电池;续驶里程;寒冷地区

Influence of fuel cell bus heater system on cruising range

ZHANG Anwen1,ZHAO Qiang2,3, LIU Huandong2,3, LI Huijun2,3

1. Weifang Public Transportation Corporation,Weifang 261061, China;2. State Key Laboratory of Engine Reliability, Weifang 261061, China;3. Weichai Power Diesel Engine Co.,Ltd., Weifang 261061, China;

Abstract: By exploring the influence of fuel cell bus heating system on vehicle endurance mileage, taking the large-scale high-class bus operating in cold area as an example, this paper analyzes the vehicle energy demand and the change of endurance mileage w/o heating system. The results show that the driving range of fuel cell bus operating in cold area decreases about 37% due to the influence of heating energy consumption. Based on the above conclusions, a heating system for fuel cell buses was designed in cold areas, which can meet the heating demand of the whole vehicle by consuming other alternative fuels, reduce the energy consumption of fuel cell engines, and improve the endurance of fuel cell buses in cold areas.

Keywords: fuel cell; mileage; cold areas

结合对象分割和深度学习的运动行人检测

吕轩轩1,2,宫法明3*

1.内燃机可靠性国家重点实验室,山东 潍坊 261061;2.潍柴动力股份有限公司 软件研究院,山东 潍坊 261000;

3.中国石油大学(华东),山东 青岛  266000

摘要:针对传统的人工标注大量训练数据集存在的成本高、效率低、难以满足大型行人检测系统检测要求的问题,研究一种半自动标注行人的方法。以静止的单目摄像机拍摄的监控视频图像为对象,利用背景差分以及显著性检测方法将前景、背景分离,提取出前景目标。试验结果表明,相对于传统的人工标注数据集的方法该方法能提高数据集标注的效率,形成的数据库可以为行人检测系统提供数据。

关键词:行人检测;背景减法;显著性检测;深度学习;半自动数据集标注

A moving pedestrian detection framework with

object segmentation and deep learning

LÜ Xuanxuan1,2GONG Faming3*

1.State Key Laboratory of Engine Reliability, Weifang, 261061 , China;2. Software Research Institute, Weichai Power Co., Ltd., Weifang, 261000 , China;3.China University of petroleum, Qingdao, 266580 , China

Abstract: Pedestrian detection is a research hotspot in the field of computer vision. The role of national public security, traffic control and other fields cannot be ignored. The traditional method uses a convolutional neural network to train the detection model and manually label a large number of training datasets. This type of method greatly improves the detection accuracy, but repeated manual labeling is costly and inefficient, and it is difficult to meet the detection requirements for large pedestrian detection systems. Aiming at the surveillance video images taken by a stationary monocular camera, a method of semi-automatic annotation of pedestrians is proposed. This detection framework uses the video object segmentation method to separate the foreground background and extract the foreground object, so as to design a semi-automatic dataset annotation method. The experimental results show that the proposed method can improve the efficiency of data annotation compared with the traditional manual annotation dataset and can be applied to the real-time pedestrian detection system.

Keywords: pedestrian detection; background subtraction; saliency detection; deep learning; semi-automatic data annotation

 

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