甲醇-汽油双燃料火花点火发动机试验研究

基于一台由缸内直喷汽油机改装而成的高压缩比双燃料汽油机,研究了甲醇-汽油双燃料喷射方式(M-G,是指进气道喷射甲醇,缸内直喷汽油)和汽油-甲醇双燃料喷射方式(G-M,是指进气道喷汽油,缸内直接喷甲醇)两种双燃料双喷方式对火花点火发动机燃烧排放特性、热效率和爆震抑制的影响。在试验过程中甲醇的喷射比例范围为0~100%。试验结果表明:相比于汽油单燃料发动机,两种双燃料喷射方式(M-G和G-M)都能够显著提高经济性、抑制爆震同时降低微粒排放;G-M双燃料喷射方式相比M-G双燃料喷射方式在抑制爆震、降低微粒排放上效果更加显著。     

氢-汽油双燃料发动机性能试验研究

介绍一种氢—汽油双燃料发动机，这种双燃料发动机装有余热制氢装置，可用甲醇制取氢并燃用氢与汽油混合燃料。作者对余热制氢装置及氢—汽油双燃料发动机的各项性能进行试验研究。试验结果表明，装有余热制氢装置的氢—汽油双燃料发动机功率和扭矩有所提高，外特性和负荷特性燃油消耗率下降5．3％一7．5％；怠速排放中CO和HC均有所减少。     

甲醇-汽油双燃料化油器性能试验研究

针对汽油机燃用甲醇问题,设计了甲醇-汽油双燃料化油器,在对发动机进行较小改动的基础上,成功解决了使用纯甲醇出现的冷起动困难、重载爬坡乏力和超车加速性能差的三大难题,达到了以80％的甲醇取代汽油进入发动机工作,而基本不影响发动机性能的效果。     

甲醇/汽油双燃料发动机燃料转换控制研究

为了从根本上解决环境污染和能源短缺问题,提出了甲醇/汽油双燃料发动机的燃油供给系统方案,并对双燃料系统的控制转换方式进行了研究,提出了双燃料系统控制方案,实现了甲醇燃料供给与汽油燃料供给系统的并行使用,它利于燃料的最优合理利用,同时满足了环保要求。     

LPG-汽油双燃料电喷发动机工作原理分析

受环境保护和能源短缺的影响,双燃料发动机改造技术在各国得到大力的发展.本文分析了LPG的燃烧特性,阐述了LPG-汽油双燃料发动机的组成及工作原理,并与汽油发动机的性能相比较,提出了改进双燃料发动机性能的一些思路.     

液化石油气发动机的性能及故障特征

分析了液化石油气（LPG）作为发动机燃料时的特点，以及LPG－汽油双燃料发动机的性能特点和实用化技术，介绍LPG发动机的发展状况，对LPG－汽油双燃料发动机的故障特征作探讨，针对此类双燃料发动机的技术调整和改进方面提出了观点。     

基于μC/OS-Ⅱ的CNG/汽油发动机ECU软件设计研究

为了满足天然气(CNC)汽油双燃料发动机高实时性、可靠性和灵活性的要求,将微控制器操作系统μC/OS-Ⅱ实时内核应用于天然气/汽油双燃料发动机电子控制单元(ECU)软件设计中,利用它的任务调度机制、同步机制及中断管理,来实现对发动机实时多任务的管理和控制.本文给出了基于微控制器LPC2292的天然气/汽油双燃料发动机的ECU硬件平台,介绍了嵌入式实时操作系统μC/OS-Ⅱ在系统硬件平台上的移植和多任务的设计方法,软件测试结果表明,该系统能满足该双燃料发动机的要求.     

甲醇／柴油双燃料发动机工作区域的试验研究

在TY1100单缸柴油机的进气管上安装了电控甲醇喷射装置,采用柴油引燃甲醇双燃料工作模式,开展了甲醇/柴油双燃料发动机工作区域的试验研究.结果表明:双燃料发动机存在由熄火界限、工作粗暴界限和碳烟排放界限三者组成的工作区域.在此区域内,甲醇/柴油双燃料发动机的万有特性曲线中最经济区域位于发动机中高转速和中高负荷区,且随着引燃柴油量的增加向发动机高转速区域移动.随着甲醇质量分数的增加,发动机Nox和碳烟排放可以同步降低.     

双燃料发动机台架测试系统研制

针对不同的发动机供油或供气系统，开发出一种测试系统，可对汽油发动机、(LPG)液化石油气发动机和LPG-汽油双燃料发动机进行燃油、燃气量精确测量。     

甲醇/柴油双燃料发动机的性能

在一台柴油机基础上，采用气道口电控喷射甲醇，缸内柴油引燃甲醇的方式，开发了电控甲醇／柴油双燃料样机，并通过发动机台架实验，研究了柴油／甲醇双燃料燃烧模式在燃烧特性、燃油经济性及排放性能方面的特点．与原发动机相比，双燃料模式的最高爆发压力下降，压力升高率上升，排烟和NOx大幅度下降，但THC和CO排放均升高．该方法能使甲醇喷射量得到精确控制以便燃烧达到最佳状态，是甲醇／柴油双燃料发动机可行的技术方案．     

甲醇燃料在车用发动机上的应用研究

结合甲醇燃料的理化特性,分别在495Q和JT468Q汽油发动机进行了燃用高比例M85甲醇汽油燃料和全甲醇燃料的对比试验。试验结果表明：直接燃烧定比例甲醇燃料时,功率和扭矩都略有提高;提高压缩比后,功率和扭矩都大幅度提高,燃油消耗也大幅度降低、排放明显改善。     

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.     

甲醇汽油在M-TEC发动机上的动力性与经济性试验研究

对M15、M85两种具有代表性的甲醇汽油在M-TEC发动机上进行了动力性和经济性的试验,分别绘制了外特性动力曲线和3000r/min下的负荷特性曲线,并对其原因进行分析。试验结果表明,使用甲醇汽油有利于发动机动力性和经济性的提升。使用M15甲醇汽油时,输出功率提高了大约5%～7%,能耗降低了大约0.7%;使用M85甲醇汽油时,输出功率提高了8%～10%,能耗降低了大约14.5%。两种燃料对动力性和经济性的提升在不同转速下也不相同,在中小负荷下动力性提升最为明显,中等负荷下经济性提升最显著。     

摩托车发动机燃用M85甲醇汽油的空燃比优化

随着世界石油资源的日趋匮乏和日益严峻的环保问题,车用发动机代用燃料的研究已成为汽车行业的当务之急。本文针对摩托车发动机燃烧M85甲醇汽油的动力性问题,利用发动机一维数值模拟软件GT-POWER对汽油发动机燃烧M85甲醇汽油时的空燃比进行了仿真优化,研究结果表明,与原汽油机相比最大扭矩下降了2.5%,最大功率可提高1.7%,有效热效率最大可提高4%,有效燃料消耗率最大可降低14%,动力性能基本上能达到原汽油机水平,燃油经济性好于原汽油机。     

甲醇-汽油混合燃料电喷汽油机性能的试验研究

在一台多点电喷汽油机上,系统开展了燃用高比例的甲醇汽油混合燃料(甲醇的体积比为85%)M85时发动机的动力性,经济性和排放特性。研究结果表明:电喷汽油机燃用M85时,动力性明显改善,经济性明显提高,有效热效率明显提高;CO和NOx的排放有明显改善,但HC排放明显恶化。     

ZS1100柴油机燃用甲醇-柴油混合燃料的试验研究

在ZS1100直喷式柴油机上,用自行配制的M15、M30甲醇-柴油混合燃料与纯柴油做了对比试验研究,进行了负荷特性、NOx和碳烟的排放对比试验,还进行了混合燃料的浊点测试和成本估算。研究结果表明,燃用M15、M30甲醇-柴油混合燃料后,发动机可以同时降低NOx排放和碳烟排放;结合成本考虑,比油耗明显下降;动力性几乎不受影响,具有良好的市场前景。     

分层燃烧甲醇发动机的研究

介绍了在1130单缸柴油机上，采用火花助燃的方法燃用甲醇燃料的研究结果。试验表明，在火花塞跳火区域及燃烧室内获得合适的混合气层状浓度分布是火花助燃甲醇发动机可靠着火和燃烧的关键。甲醇发动机的动力性与柴油机相当，大负荷经济性比柴油机好，并能实现无烟燃烧。     

Vehicle evaluation of neat methanol—compromises among exhaust emissions,fuel economy and driveability

Methanol was evaluated as an alternative fuel in vehicles with spark-ignited, internal-combustion engines. Acceptable driveability was achieved with a methanol-fuelled car equipped with electronic fuel injection (EFI) which was modified to provide proper air-fuel ratios for methanol. the target level for driveability was not achieved with a methanol-fuelled carburetted car modified to provide proper air-fuel ratios for and increased vaporization of methanol. With the EFI car, using the average equivalence ratio (Φ_a = 0·96) and spark timing designed for the production gasoline car, exhaust emissions and fuel economy with methanol fuelling were compared to those with gasoline. With methanol, compared with gasoline, 60 per cent lower NO_x, 3·5 times higher unburned fuel emissions (UBF), and similar CO engine emissions were measured. the air pollution significance of the higher UBF emissions from methanol combustion is unknown because the UBF species (mainly methanol) are different from those from gasoline combustion. A catalytic converter decreased emissions of UBF and CO similarly for both fuels. Fuel economy with methanol—about half that of gasoline on a volume basis—was 7–10 per cent better on an energy basis than that with gasoline. With methanol fuelling, spark timing and Φ_a were varied from production values to obtain a more acceptable compromise among driveability, exhaust emissions and fuel economy. While fuelling with methanol at Φ_a = 0·96, using best power rather than production spark timing increased fuel economy 3 to 6 per cent without significantly affecting emissions and driveability. As Φ_a was leaned to 0·62 while maintaining best-power spark timing engine and tailpipe (after converter) CO emissions decreased, engine UBF emissions increased, NO_x and tailpipe UBF emissions were not greatly affected, and driveability deteriorated. With best-power spark timing and the Φ_a for maximum economy (0·83), driveability was acceptable, and CO and NO_x emissions met the 1977 standards. At Φ_a = 0·83, NO_x emissions were reduced below the statutory standard (0·4 g/mile) by retarding spark timing; however, driveability and fuel economy deteriorated. Although the feasibility and benefits of operating vehicles with neat methanol have been demonstrated, not all problems of methanol fuelling (for example, cold start) were addressed. In addition, other alternatives such as obtaining hydrocarbon liquids from coal or using methanol as fuel for stationary powerplants must also be considered to obtain the most efficient utilization of energy resources.     

DME-LPG混合燃料的试验研究

通过在火花点火式发动机燃用二甲醚混合燃料与汽油的对比试验,评价了二甲醚混合燃料的不同组份在发动机上的应用特性,分析了由二甲醚、液化石油气和甲醇组成的两种配比混合燃料的经济性能、动力性能及怠速时的排放性能。结果表明,发动机燃用二甲醚—液化石油气混合燃料基本达到了燃用汽油的水平。     

喷油脉宽对电控汽油机燃用M85甲醇汽油的影响

为了在电控汽油机上优化M85甲醇汽油的应用,利用发动机台架试验,分析了电控汽油机直接燃用M85的主要问题,并通过放大喷油脉宽,增加M85甲醇汽油的喷油量来改善发动机性能。试验结果表明：与燃用汽油相比,喷油脉宽放大1．3倍时,发动机燃用M85甲醇汽油的功率和扭矩分别平均降低了6．83％和7．15％;小时燃油消耗量与有效燃油消耗率增大,但有效能耗平均降低6％;CO和HC排放分别平均降低11．28％和0．64％;NOx排放平均增加55．56％。