共查询到20条相似文献，搜索用时 129 毫秒
1.
杨梅 《北京工业职业技术学院学报》2005,4(1):80-84
天然气作为燃料具有低排放、低消耗的优点,天然气/柴油双燃料发动机通过应用电控喷气技术,可以实现较高的发动机综合性能.本文系统介绍双燃料发动机电控系统的结构及特性等. 相似文献
2.
Biogas from renewable sources and natural gas (NG) are both high-efficient and good-quality gaseous fuels on account of their enrichment in methane. Due to the dissimilar physical properties of biogas and NG, biogas cannot substitute NG directly without treatment and is usually used on site due to the high cost of the transportation and distribution via exclusive pipeline system. Consequently, the injection of biogas into existing NG infrastructure was proposed to address the deficiency. In this paper, the Wobbe index (WI) as well as the combustion potential (CP) were introduced for analyzing the interchangeability of an NG-biogas mixture, and a mathematical framework was put forward for modeling and simulating NG grid with a decentralized biogas injection. Results show that the maximum admissible amount of biogas in mixture was 10.5 by volume. A medium pressure network was used to interrogate the comprehensive effect of distributed biogas injection, which showed an impact on both gas quality and hydraulic regime across the grid. 相似文献
3.
张文 《天津成人高等学校联合学报》2011,(8):26-29
文章介绍了汽车尾气污染物的危害以及NOX的生成机理,从废气再循环技术、缸内直喷式燃烧技术、代用燃料、电子控制技术、催化还原技术等几个方面,对降低汽车尾气中NOX的排放技术进行了研究。 相似文献
4.
张文 《天津职业院校联合学报》2011,13(8):26-29
文章介绍了汽车尾气污染物的危害以及NOX的生成机理,从废气再循环技术、缸内直喷式燃烧技术、代用燃料、电子控制技术、催化还原技术等几个方面,对降低汽车尾气中NOX的排放技术进行了研究。 相似文献
5.
The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory. 相似文献
6.
Experimental Study on Dimethyl Ether Combustion Process in Homogeneous Charge Compression Ignition Mode 总被引：2，自引：0，他引：2
Experimental study on homogeneous charge compression ignition (HCCI) combustion process was carried out on a single-cylinder direct injection diesel engine fueled with dimethyl ether(DME). The influence of inert gas CO2 on the ignition and combustion process was investigated. The research results indicate that because of the high cetanc number of DME, the stable HCCI operating range is quite narrow while the engine has a high compression ratio. The HCCI operating range can be largely extended when the inert gas is inducted into the charging air. HCCI combustion of DME presents remarkable characteristic of two-stage combustion process. As the concentration of inert gas increases, the ignition timing of the first combustion stage delays,the peak heat release rate decreases, and the combustion duration extends. Inducting inert gas into charging air cannot make the combustion and heat release of DME occur at a perfect crank angle position. Therefore, to obtain HCCI operation for the fuel with high cetane number,other methods such as reducing engine compression ratio should be adopted. Emission results show that under HCCI operation, a nearly zero NOx emission can be obtained with no smoke emissions. But the HC and CO emissions are high, and beth rise with the increase of the concentration of inert gases. 相似文献
7.
乙醇柴油的不同配比、供油提前角、喷油压力、喷油泵柱塞直径及行程燃烧室的型式等参数的调整,对乙醇柴油混合燃料的柴油机动力性、经济性、排放指标等有重要的影响．参数调整后的乙醇柴油发动机经济性和排放指标皆优于纯柴油发动机,动力性略低于纯柴油发动机． 相似文献
8.
介绍了内燃机专业实验室建设的新模式,即按照为"产品研究、开发、制造、检测、使用、维修、改进"工程链全过程服务的"工程模式",及其在实践中形成的集教学、科研与服务地方经济建设于一体的实验室多功能特色。 相似文献
9.
The present work used a methane-air mixture chemical kinetics scheme consisting of 119 elementary reaction steps and 41 chemical
species to develop a simplified combustion model for prediction of the knock in dual fuel engines. Calculated values by the
model for natural gas operation showed good agreement with corresponding experimental values over a broad range of operating
conditions.
Project (No. 50106014) supported by the National Natural Science Foundation of China 相似文献
10.
Emissions of dimethyl ether （DME） fuelled engines were investigated by orthogonal experiments on a ZS195 diesel engine. The study mainly focused on the tiny pollutant emissions of formaldehyde （CH2O）, methyl formate （CH3OCHO） and formic acid （HCOOH）. The presence of CH2O, CH3OCHO and HCOOH are proved in the exhaust by gas chromatograph and Fourier transform infrared spectroscopy. The analysis of variance results indicate that the fuel delivery advance angle is the most important factor for CH2O emission. The fuel delivery advance angle and the interaction of injection pressure and nozzle diameter are considerable factors for unburned hydrocarbon （UHC） emission. The mechanism forming tiny pollutants, primarily through CH2O formation, is suggested to be similar to the mechanism forming UHC by DME partial oxidation existing in crevices and boundary zones, and is verified via DME combustion simulation of a multizone chemical kinetic model. 相似文献
11.
黄忠民 《泰州职业技术学院学报》2005,5(1):69-71
柴油机具有比汽油机更高的可靠性、经济性,因而应用也日益广泛,而柴油机的故障原因、诊断排除与汽油机又不尽相同,主要从高、低压油路;柴油的品质;喷油量及喷油质量等方面讨论了柴油机起动困难的原因及故障排除,并通过实例对其进行分析. 相似文献
12.
INTRODUCTIONDuetodwindlingfueloilreservesandthedesireforreducedpollutantemissions,naturalgas,whichisdominantlycomposedofmethane,hasbeennowwidelyusedasanalternativefuelininternalcombustionengines .Aconventionaldieselenginecanbeconvertedwithoutexcessiveincr… 相似文献
13.
应用Chemkin化学动力学软件包中的Senkin模块模拟了正庚烷在多孔介质发动机中的燃烧过程．通过修改Senkin程序,结合了Woschni传热模型和多孔介质换热模型,并在正庚烷详细氧化机理中加入氮氧化物的生成机理,将此程序纳入发动机燃烧的零维单区模型．对多种工况参数进行计算,讨论了运行参数对发动机性能的影响．当进气温度、压缩比增大,或过量空气系数降低时,多孔介质发动机着火时刻会明显提前．结果表明：多孔介质对混合气具有预热作用可强化发动机的点火燃烧,多孔介质的初始温度是决定压燃点火的决定性因素． 相似文献
14.
15.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
16.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
17.
Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range.Furthermore,a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments.The heat release correlation was described in two parts,one is for the first slower heat release process at low temperature,and the other is for the second faster heat release process at high temperature.Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program.The results show that the predicted loads and ignition timings match closely with the measurements. 相似文献
18.
由于自主研发的快速压缩机进气时间长,缸内混合气与活塞、缸壁、缸盖等进行充分热交换而引起进气温度发生变化,影响燃烧特性分析结果。为此对快速压缩机燃烧缸进行测温,分别测得不同混合气温度和不同混合气压力对燃烧缸温度场的影响。结果表明,充气结束20s后燃烧缸内温度场与进气温度及进气压力关系不大,并采用最小二乘法拟合出燃烧缸内平均温度与缸盖上测量热电偶读数间的函数关系,采用修正后的进气温度使发动机模拟试验数据更加真实可靠,提高了燃烧特性分析的精确度和准确度。 相似文献
19.
李健 《天津工程师范学院学报》2003,13(2):22-24
柴油机是最有效的内燃动力装置,高速载货汽车、城市客车和工业设施几乎都采用柴油机,而重型柴油机的尾气是烟雾和酸雨的主要来源。因此,改进和开发汽车尾气控制技术就成为汽车设计者们一大攻关问题,文章就此问题进行阐述。 相似文献
20.
Three-dimensional transient numerical simulation for gas exchange process in a four-stroke motorcycle engine 总被引：3，自引：0，他引：3
INTRODUCTION In-cylinder flow characteristics during fuel in-jection and subsequent interactions with fuel sprays and combustion are important effect on engine per-formance and exhaust emissions of an engine(Floch et al.,1998;Kim et al.,1999).Four key parameters control the flow field in an engine:the mean flow components,the stability of the mean flow,the tem-poral turbulence evolution during the intake and compression strokes,and the mean velocity near the spark gap at the time of ignit… 相似文献