Combustion and emissions of the diesel engine using bio-diesel fuel

The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the specific fuel consumption of bio-diesel increases by about 12%. The emissions, such as CO, HC, and particulate matter decrease remarkably whereas NO _x increases a little. __________ Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(3): 216–219 [译自: 江苏大学学报(自然科学版)]     

Combustion characteristics of an agricultural diesel engine using biodiesel fuel

Biodiesel has great potential as an alternative fuel for diesel engines that would reduce air pollution. It is a domestically produced, renewable fuel that can be manufactured from fresh or used vegetable oils, or from animal fats. In this study, a biodiesel fuel derived from rice bran oil was tested as an alternative fuel for agricultural diesel engines. The emissions were characterized for both neat and blended biodiesel fuels, and for conventional diesel fuel. Since this biodiesel fuel contained 11% oxygen, it strongly influenced the combustion process. The use of biodiesel fuel resulted in lower carbon monoxide, carbon dioxide, and smoke emissions, without any increase in nitrous oxide emissions. The study demonstrated that biodiesel fuel could be effectively used as a renewable and environmentally innocuous fuel for agricultural diesel engines.     

The influence of engine oil on diesel exhaust emissions

Increasingly stringent emission legislation, together with the requirements for improved diesel engine performance, such as fuel economy, friction reduction, and extended drain intervals, have led to attention being focused on engine oil quality. The use of low‐friction engine oils can improve engine fuel efficiency and lead to a significant reduction of gaseous emissions. Therefore, engine oil is of importance when considering engine design parameters. This paper describes a study of the contribution of engine oil to diesel exhaust emissions. The investigations have shown that diesel engine particulate emissions as well as hydrocarbons and NO_X emissions depend on the lubricant oil properties, in particular on the sulphur content, volatility, and metal content.     

Combustion characteristics of a swirl chamber type diesel engine

A numerical model that utilizes Computational Fluid Dynamics (CFD) techniques is simulated for the analysis of a swirl chamber type diesel engine. This research also reveals the effects of swirl chamber passage hole geometry on the combustion characteristics of a swirl chamber type diesel engine depending on the shape, angle, and area of the jet passage. Turbulence kinetic energy is generated by compound effects of the pressure, heat release, NOx concentrations, and soot concentrations. Results show that combustion characteristics are affected by the passage hole areas and the passage hole inclination angles.     

单缸柴油机喷油系统的模拟计算与试验研究

利用AVL-HYDISM模拟软件建立了1105柴油机喷油系统的仿真模型,模拟了此柴油机标定工况下的喷油性能,从高压油管泵端压力以及嘴端压力两方面与试验值进行了比较,同时计算得出了样机燃油喷射规律以及压力室油压.分析了样机不足,通过改进供油凸轮使得燃油喷射压力得到提高.     

Characterization of engine oil additive packages on diesel particulate emissions

This study investigated the impact of engine oil formulation on particulate matter (PM) characteristics from a light-duty diesel engine. The test engine was a 1.6 L Euro-5 diesel engine operated from low- to high-speed and high-load conditions. Specially formulated nonadditive containing base oil and genuine oil were evaluated. For diesel PM characterization, physicochemical analytic procedures were conducted on engine oil formulation, oil flushing, PMs sampling, morphology, and particle constituent determination. Size-resolved particle number (PN) concentration at the engine-out position was evaluated by differential mobility spectrometer (DMS). Nucleation mode particles originating from engine oil consumption during the expansion stroke had a higher concentration from genuine oil than those from base oil. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the morphology patterns and atomic compositions with engine oil packages. From the SEM analysis, spherical PM of nucleation and accumulation mode particles were agglomerated on a quartz filter. In the XPS spectrum, more engine oil additive fractions of Ca, P, and Zn were found in the PM sample from genuine oil. In conclusion, the variation of physicochemical engine oil properties and additive amounts had strong contributions to engine oil derived PN emissions, morphology, and additive metal compositions in the exhaust gas stream.

     

Calculation of fuel spray impingement and fuel film formation in an HSDI diesel engine

Spray impingement and fuel film formation models with cavitation have been developed and incorporated into the computational fluid dynamics code, STAR-CD. The spray/wall interaction process was modeled by considering the effects of surface temperature conditions and fuel film formation. The behavior of fuel droplets after impingement was divided into rebound, spread and splash using the Weber number and parameter $K(\sqrt {We\sqrt {Re} } )$ . The spray impingement model accounts for mass conservation, energy conservation, and heat transfer to the impinging droplets. The fuel film formation model was developed by integrating the continuity, momentum, and energy equations along the direction of fuel film thickness. Zero dimensional cavitation model was adopted in order to consider the cavitation phenomena and to give reasonable initial conditions for spray injection. Numerical simulations of spray tip penetration, spray impingement patterns, and the mass of film-state fuel matched well with the experimental data. The spray impingement and fuel film formation models have been applied to study spray/wall impingement in high-speed direct injection diesel engines.     

甲醇裂解气-柴油混合燃料对柴油机排放的影响

为研究甲醇裂解气-柴油混合燃料对柴油机排放的影响,设计了一种集成式尾气裂解甲醇反应器和进气共轨系统,将YC6A220型柴油机改装成燃烧由甲醇裂解而成的氢富气与柴油混合燃料的柴油机。实验研究表明,改装后的柴油机在中、高负荷运行时可以使NOx、HC和碳烟大幅度降低,且随着甲醇裂解气掺烧量的增加,各排放物质的减少量增加。     

Multidimensional engine modeling: NO and soot emissions in a diesel engine with Exhaust Gas Recirculation

The effects of EGR (Exhaust Gas Recirculation) on heavy-duty diesel engine performance, NO and soot emissions were numerically investigated using the modified KIVA-3V code. For the fuel spray, the atomization model based on the linear stability analysis and spray wall impingement model were developed for the KIVA-3V code. The Zeldovich mechanism for the formation of nitric oxide and the soot model suggested by Hiroyasu et al. were used to predict the diesel emissions. In this paper, the computational results of fuel spray, cylinder pressure, and emissions were compared with experimental data, and the optimum EGR rates were sought from the NO and soot emissions trade-off. The results showed that the EGR is effective in suppressing NO but the soot emission was increased considerably by EGR. Using cooled EGR, soot emission could be enhanced without worsening of NO.     

Analysis of engine temperature and energy flow in diesel engine using engine thermal management

Recently, precise analysis of energy flow in engines has become necessary to improve fuel economy. An integrated engine thermal management model, which is introduced in this paper, is suitable for that process. The model consists of six sub-models for thermal mass, coolant, lubricant, heat transfer, friction, and exhaust. The sub-models are coupled to each other and they exchange heat and signals. Combustion energy flow analysis and temperature estimation of the engine components and working fluids were simulated under various conditions. Simulation results were compared with experimental data and they showed good agreement. Then, a variable-speed water pump (VSWP) to control coolant flow was applied in place of a conventional water pump. Engine warm-up time decreased with proper coolant flow control, and fuel economy could be improved by 2.5%.     

The effect of water emulsified fuel on a motorway-bus diesel engine

In this study, the combustion characteristics and durability of a diesel engine using emulsified fuel was investigated. Water was used in oil type emulsified fuel. In order to understand the effect of emulsified fuel in a wide range of engine running conditions, D-13 mode was selected as a test condition, and a durability test was included to understand the long-term effect of water. Combustion pressure in a cylinder, exhaust emissions, specific fuel consumption, sound level and maximum torque were measured. NOx and PM were simultaneously reduced and the specific fuel consumption was increased and decreased at low and high loads, respectively. There was no trouble and any damage on the parts of the cylinder during a 500 hour durability test.     

The effect of biodiesel and ultra low sulfur diesel fuels on emissions in 11,000 CC heavy-duty diesel engine

It seems very difficult to comply with upcoming stringent emission standards in vehicles To develop low emission engines, better quality of automotive fuels must be achieved Since sulfur contents in diesel fuels are transformed to sulfate—laden particulate matters as a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied In general, flash point, distillation 90% and cetane index are improved but viscosity can be worse in the process of desulfunzation of diesel fuel Excessive reduction of sulfur may cause to degrade viscosity of fuels and engine performance in fuel injection systems This research focused on the performance of an 11,000 cc diesel engine and emission characteristics by the introduction of ULSD, bio-diesel and a diesel oxidation catalyst, where the bio—diesel was used to improve viscosity of fuels in fuel injection systems as fuel additives or alternative fuels     

小型通用汽油机燃用甲醇/汽油排放研究

在168F通用小型汽油机上,按照EPA制定的排放法规中的6工况方法,测量了燃用汽油与甲醇汽油混合燃料M15、M25的HC、NOx、CO常规排放和甲醛、乙醛非常规排放污染物随负荷的变化规律。结果表明:甲醇作为一种含氧燃料,其低热值及高汽化潜热使得HC、CO排放量会随着甲醇掺入量的增加而降低,NOx排放量则随着甲醇掺入量的增加而增加;甲醛、乙醛的排放量均随甲醇掺入量的增加而降低。汽油机能耗率随着甲醇掺入量的增加而降低。     

Investigation of the effects of steam injection on the emissions and performance of a diesel engine using waste chicken oil methyl ester

The use of biodiesel-blended fuels in diesel engines improves the engine performance parameters and the partial recovery of incomplete combustion products, while also increasing the level of NOx emissions. In this study; biodiesel obtained through the transesterification of waste chicken frying oil was mixed with diesel fuel (90% diesel + 10% biodiesel-B10), and was then used as fuel in a direct injection diesel engine. To reduce the increased NOx emissions caused by the use of B10 fuel, the steam injection method (which is one of the NOx reduction methods) was applied. Steam was injected into the intake manifold at different ratios (5%-S5, 10%-S10 and 15%-S15) and at the time of the induction stroke with the aid of an electronically controlled system. Based on the study results, it was observed that steam injection into the engine using B10 fuel improved both the engine performance and the exhaust emission parameters. It was determined that the S15 steam injection ratio resulted in the best engine performance and emissions parameters. In comparison to STD fuel; the highest increase observed at the S15 steam injection ratio in the effective engine power was 2.2%, while the highest decrease in the specific fuel consumption was 3.4%, the highest increase in the effective efficiency was 3.5%, and the highest decrease in NOx emissions was 13.7%.

     

柴油机的排放、测量标准与柴油机未来发展

1 内燃机行业的形势 在我国，整个柴油机行业存在着能源、环保和加入世贸组织后的竞争三种危机： 1）连续3年我国石油开采量在1.6亿吨以上，但储备量很有限，从1993年开始我国是纯石油进口国，而石油产品的50%用于内燃机行业。 2）去年322个城市的大气质量达到或超过3类指标，全球污染最严重的15个城市，中国占7个。环保要求对柴油机行业来讲，将愈来愈严格。尤其对于车用发动机来说是致命的。 3）加入世贸组织后，随着关税的减让和全球采购的进行，低价优势就不再存在，再加上1997年后农民的购买力没有实质性增加，所以柴油机行业的竞争非…     

磁化燃料在降低柴油机微粒排放中的应用

为满足日益严格的排放法规要求,柴油机微粒排放的控制已成为柴油机进一步发展急需解决的问题.通过对燃油磁化机理分析,并在常柴牌295型柴油机上进行试验,研究了磁化对柴油机微粒排放的影响.     

柴油/CNG双燃料汽车发动机的性能研究

以某柴油/CNG双燃料发动机为对象,研究了它的结构特点和工作原理,并进行了发动机性能试验.结果表明,柴油机在改为柴油/CNG双燃料发动机后功率和扭矩均有所下降,最大值达到了9%左右,但经济性变好了,最多可以节省24%,排放性也明显得到了改善.通过采用一定的措施,可以使柴油/CNG的动力性恢复,从而弥补CNG带来的不足,使得柴油/CNG发动机具有了动力性、经济性、排放性较好的特点.     

正确使用和维护保养R180柴油机的方法

通过对R180柴油机的正确地使用和维护，可以延长柴油机的使用寿命，提高工作效率。这里介绍在使用和维护保养柴油机中必须注意的问题。     

Influence of injection rate shaping on combustion and emissions for a medium duty diesel engine

This paper describes the effects of injection rate shaping on the combustion, fuel consumption and emission of NO_X and soot of a medium duty diesel engine. The focus is on the influence of four different injection rate shapes; square type 1, square type 2, boot and ramp, with a variation of maximum injection pressure and start of injection (SOI). The experiments were carried out on a 1 liter single cylinder research diesel engine equipped with an amplifier-piston common rail injection system, allowing the adjustment of the injection pressure during the injection event and thus injection rate as desired. Two strategies to maintain the injected fuel mass constant were followed. One where rate shaping is applied at constant injection duration with different peak injection pressure and one strategy where rate shaping is applied at a constant peak injection pressure, but with variable injection duration. Injection rate shaping was found to have a large effect on the premixed and diffusion combustion, a significant influence on NO_x emissions and depending on the followed strategy, moderate or no influence on soot emission. Only small effects on indicated fuel consumption were found.     

The experimental investigations of recirculated exhaust gas on exhaust emissions in a diesel engine

The effects of recirculated exhaust gas on the characteristics of NOx and soot emissions under a wide range of engine loads were experimentally investigated by using a four-cycle, four-cylinder, swirl chamber type, water-cooled diesel engine operating at three engine speeds. The purpose of this study was to develop the EGR-control system for reducing NOx and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions, and a novel diesel soot removal device with a cylinder-type scrubber for the experiment system was specially designed and manufactured to reduce soot contents in the recirculated exhaust gas to the intake system of the engine. The experiments were performed at the fixed fuel injection timing of 4° ATDC regardless of experimental conditions. It was found that soot emissions in exhaust gases were reduced by 20 to 70% when the scrubber was applied in the range of the experimental conditions, and that NOx emissions decreased markedly, especially at higher loads, while soot emissions increased owing to the decrease in intake and exhaust oxygen concentrations, and the increase in equivalence ratio as the EGR rate is elevated.