火花助燃甲醇发动机的性能和排放

本文通过在1130单缸柴油机上燃用全甲醇的试验,研究了油线分布、压缩比、喷嘴针阀开启压力对甲醇发动机性能的影响,并对甲醇发动机的废气排放水平做出了评价。 试验是在1130单缸立式水冷直喷柴油机上进行的。柴油发动机缸径为130mm,行程为150mm,ω型燃烧室,压缩比为16,4×φ0.33mm喷油嘴,喷嘴针阀开启压力为17.5MPa。     

火花助燃甲醇发动机燃烧特性的研究

本通过对１１３０单缸柴油机采用火花助燃燃用甲醇燃料时的气缸压力进行测量和分析，探讨了各种参数对甲醇发动机燃烧过程和性能的影响。     

采用电热塞助燃法在原压燃式发动机中燃用甲醇的试验研究

为了使甲醇能够顺利地应用于原压燃式发动机,我们采用了“电热塞助燃法”,对X1105型柴油机进行了改装,在缸盖上安装了电热塞且档板采用了双孔喷嘴,实验结果表明,这种方法是行之有效的,本文通过大量的实验结果,分析了该发动机分别燃用甲醇,柴油时,热效率不同的原因,并分析了发动机转速,负荷对发动机燃用甲醇的影响,经过对废气和烟度的测量表明,发动机燃用纯甲醇基本上可以实现无烟燃烧。     

重型M100甲醇发动机排放及燃烧热效率分布研究

甲醇作为重要的车用发动机替代燃料,其排放性能和燃烧热效率一直是行业内关注的热点。为研究法规工况下甲醇发动机的排放性能及燃烧热效率分布,通过在一台自主研发的重型M100甲醇发动机上进行了重型汽油机瞬态循环(GB 14762—2008)和ETC循环(GB 17691—2005)试验。研究结果表明:M100甲醇发动机的排放污染物值远低于现有法规限值;发动机燃烧热效率与同等排量的其它燃料发动机相当;重型汽油机瞬态循环下的排放性能优于ETC循环,而平均燃烧热效率稍差。     

S195柴油机燃用纯甲醇、采用多火花助燃的研究

本文介绍了在S 195柴油机上燃用纯甲醇、采用多火花助燃的研究结果。选取合适的火花塞电极间隙、电极间隙与喷注空间匹配和正确的喷油、点火定时是保证非均相可燃混合气可靠着火燃烧的关键。当优化了上述参数后,发动机能在广阔的转速、负荷范围内稳定运行。燃用纯甲醇的柴油机与燃用柴油时热效率接近,并能实现无烟燃烧。试验表明,这种高压缩比、强涡流的柴油机对多火花点火系统有更好的适应性。     

甲醇燃料在柴油机中的应用与发展

本文论述了我国发展甲醇燃料的必要性，并分析了甲醇作为柴油机代用燃料的优势和不利因素，详细阐述了目前发动机燃用甲醇燃料的各种方法及其优缺点，指出了今后柴油机燃用甲醇燃料的趋势。     

甲醇燃料综合测试评价体系研究及应用

建立甲醇燃料综合测试评价体系进行了甲醇汽油互溶性、金属腐蚀性和非金属溶胀性研究,对燃油系统中从燃油箱到喷油器的零部件性能影响进行测试,并完成了相应的发动机动力性、经济性、排放特性和可靠性试验及整车动力性、经济性、排放特性分析研究。研究结果表明:甲醇燃料综合测试评价体系能够全面评估甲醇燃料在车用发动机上的使用特性;添加合适的助溶剂能够提高甲醇汽油的物理稳定性和抗水性;甲醇汽油对金属具有腐蚀作用,对非金属材料具有较强的溶胀作用;且甲醇汽油发动机和整车的动力性、经济性和排放特性等综合性能获得改善,M15甲醇汽油发动机可靠性良好。     

低压空气辅助喷射甲醇发动机冷起动试验研究北大核心CSCD

针对甲醇发动机难以形成浓度合适的混合气而造成冷起动困难的问题,以一台应用自主开发的进气道低压空气辅助喷射系统(air assisted port injection,AAPI)的单缸甲醇发动机为研究对象开展试验研究,探究不采用辅助措施通过AAPI喷射实现甲醇高雾化对甲醇发动机冷起动的影响及规律。试验表明AAPI明显加快了甲醇发动机冷起动前可燃混合气的形成速率。AAPI甲醇发动机着火前过量空气系数λ的平均变化率值和峰值变化率分别是普通喷射方式的3.2倍和2.26倍。点火时刻对AAPI甲醇发动机冷起动影响较大,为使AAPI甲醇发动机的冷起动性能最优,需配合合适的点火时刻,试验条件下最佳点火时刻为活塞压缩上止点前20°。AAPI甲醇发动机的冷起动性能受环境温度影响较大,随着环境温度的降低,甲醇发动机冷起动时间增长;不采用辅助措施,AAPI甲醇发动机在5℃时能实现可靠冷起动。     

直喷式柴油机燃用不同燃料时的工作稳定性与燃烧特性

本文介绍了在一台直喷式柴油机上利用电火花助燃,燃用甲醇、乙醇、汽油等低十六烷值燃料的研究状况。详细分析与比较了发动机燃用上述三种燃料和柴油的着火特性、放热率、循环压力变动、NO_x排放、热效率等燃烧特性参数。     

EQ6100发动机掺烧甲醇对动力性及经济性的影响

本文针对EQ6100发动机使用以杂笨为助溶剂的甲醇汽油混合燃料进行了试验研究。试验中调整了影响性能的主要参数,取得了较理想的效果。文中还对燃料的性质、成分及成本进行了综合分析,研究了增加混合燃料中甲醇的比例对发动机性能的影响,为混合燃料的进一步推广应用创造了有利条件。     

Variation of spark plug type and spark gap with hydrogen and methanol added gasoline fuel: Performance characteristics

In this study, the performance of different spark plugs was tested with varied spark gap sizes in a spark-ignited engine. Gasoline fuel was enriched with hydrogen and methanol to evaluate how much they affect the performance of the engine. The engine tests were performed with a four-stroke, single-cylinder, naturally aspirated, variable compression ratio (VCR) spark ignition engine. 1500 rpm engine speed and MBT for spark timing were applied throughout all experiments. Iridium, platinum and conventional (copper) spark plugs were tested using 3 different spark plug gaps (SPG) (0.6 mm, 0.8 mm, 1 mm). Depending on the experimental condition, hydrogen was added with 3 l/min of flow rate and methanol was used with 10% of volume fraction in the total liquid fuel. As for performance criteria, brake power (BP) and brake specific fuel consumption (BSFC) values were obtained from the test engine. According to the findings, platinum and iridium spark plugs had shown better performance than conventional spark plugs. The increment of SPG size improved the performance of the engine, too. On the other hand, despite methanol addition to gasoline fuel reduced performance, this loss could be compensated by hydrogen enrichment. Additionally, multiple linear regression (MLR) technique was applied through experimental results to obtain a linear relationship between explanatory variables (inputs) and response variables (outputs). An MLR model was set with four selected input variables (spark plug type, hydrogen flow rate, methanol ratio, and spark gap) to estimate BP and BSFC. Prediction equations showed that experimentally obtained results were in good agreement with MLR results.     

采用离子电流分析法实现发动机爆震信号的正确检测

本描述了了种直接利用火花塞电极作为传感器检测发动机爆震的方法。作在章中详细分析及讨论了离子电流的产生机理及影响其测量的因素，并利用这一方法在发动机做了大量的试验研究，获得了宝贵的第一手资料。为了获得正确的信号检测，作在火花塞电极上加一定的直汉电压、使其能灵敏的感受燃气密度的变化。     

240火花塞式燃气机预燃燃烧技术研究

针对目前国内外气缸直径200mm、单缸排量10L以上火花塞式四冲程燃气机热效率低、热负荷高、可靠性低等问题，以南车资阳机车有限公司240火花塞式燃气机（燃气主要成分为CH4）为例，简要介绍对解决这些问题进行的预燃燃烧技术研究。     

发动机单双火花塞点火性能对比研究

在一台传统的四冲程摩托车发动机上进行了单火花塞和双火花塞点火性能的试验研究,通过对两种点火情况下压力传感器采集的气缸燃烧压力信号的比较分析。结果表明,采用双火花塞点火不但有利于发动机动力性能的提高,而且使发动机的循环变动率大大降低,明显改善了发动机的性能。     

The optimization of leading spark plug location and its influences on combustion and leakage in a hydrogen-fueled Wankel rotary engine

The hydrogen-fueled Wankel rotary engine with excellent power and emission characteristic is under spotlight, while the leakage is still the major problem for Wankel rotary engine, especially the leading spark plug leakage. The peak pressure is increased from 3.34 MPa to 3.52 MPa and the indicated thermal efficiency reaches maximum value of 38.29% when the moving distance of leading spark plug is −6.5 mm, and the mass of leakage fresh mixture is reduced from 0.00311 g to 0 g. When leading spark plug is moved to minor axis, the flow field structure of working chamber is enhanced. However, the peak pressure and indicated thermal efficiency decrease when the moving distance of leading spark plug exceeds −6.5 mm. The excess leakage residual gas has negative effects on combustion. The optimum moving distance of leading spark plug is −6.5 mm at 3000 rpm with λ of 1.6.     

Vehicle driving cycle performance of the spark-less di-ji hydrogen engine

The paper describes coupled CFD combustion simulations and CAE engine performance computations to describe the operation over the full range of load and speed of an always lean burn, Direct Injection Jet Ignition (DI–JI) hydrogen engine. Jet ignition pre-chambers and direct injection are enablers of high efficiencies and load control by quantity of fuel injected. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the spark-less pre-chamber of the DI–JI engine, where it mixes with the air entering from the main chamber and auto-ignites because of the high temperature of the hot glow plug. Then, jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. Engine maps of brake specific fuel consumption vs. speed and brake mean effective pressure are computed first. CAE vehicle simulations are finally performed evaluating the fuel consumption over emission cycles of a vehicle equipped with this engine.     

点火方式对汽油机燃烧过程的影响

通过基本结构的微小变动,将单火花塞点火(single spark ignition,SSI)改造成双火花塞点火(dual spark ignition,DSI),运用三维仿真软件AVL FIRE模拟仿真,并通过试验验证。再对单火花塞点火、双火花塞同步点火(dual synchronous spark ignition,DSSI)、异步点火(dual asynchronous spark ignition,DASI)3种不同的点火方式进行对比。结果表明:在6500 r/min转速全负荷状态下,空气过量系数为1.00而其他参数调整为最佳时,单火花塞的最佳点火提前角为29°,在空气过量系数为1.15的最佳参数下,双火花塞同步点火的最佳点火提前角为22°,双火花塞异步点火的最佳点火提前角为22°和24°。其中,发动机综合性能在双火花塞异步点火条件下表现最好:相对于单火花塞点火指示功提升8.49%;相对于同步点火,可将最高燃烧压力和压缩负功减小,指示功提升3.60%;同时改善了排放性。上述研究中发动机均控制在未发生爆震情况下。     

进气道和燃烧室形状对火花点火发动机燃烧过程影响的研究

本文针对ＣＡ６１０２发动机燃烧慢、循环变动率偏大等问题，对进气道和燃烧室进行了改进。研究了不同进气道和燃烧结构（六种匹配方案）对燃烧过程和性能的影响，发现涡流比和性能之间无单调的相关关系，与燃烧期之间存在二次抛物线型的逆变相关关系，ＣＡ６１０２发动机合适的涡流比在０．９左右，燃烧室设计因素中火花塞的位置对燃烧过程和性能影响最大，火花塞靠近中心布置方案同原机相比，最低燃油消耗率降低了４．１％，最大扭