连续再生颗粒捕集器对燃用生物柴油的柴油机颗粒物以及多环芳香烃的影响研究

为探究降低柴油机微粒及多环芳香烃的有效排放控制措施,在一台燃用生物柴油的增压多缸柴油机上应用连续再生微粒捕集器系统,研究了柴油机燃用生物柴油及采用连续再生微粒捕集器系统后对柴油机微粒和多环芳香烃排放的影响。研究结果显示:柴油机微粒排放呈现核态与聚集态形式并且粒子粒径呈现多峰值化特征,燃用生物柴油对核态微粒粒径浓度影响不大,而聚集态微粒排放则有着较为明显的下降趋势,采用连续再生颗粒捕集器后最大下降幅度达到94.6%。柴油机微粒排放中核态粒子浓度占60%以上,燃用生物柴油后该值进一步提升,在试验工况下最大可达到95%。连续可再生微粒捕集器对聚集态粒子捕集效率高,最高可达到96%,试验用柴油机使用生物柴油后,由于核态颗粒数量浓度的提升致使捕集器系统效率有所下降。燃用生物柴油可有效降低绝大部分的多环芳香烃的排放,但测试结果显示:和苯芘蒽排放不降反升,与连续可再生微粒捕集器系统结合,能让菲、芘、苯芘等6种物质排放下降幅度更大。     

BTL/柴油混合燃料对柴油机瞬态工况微粒粒度分布的影响

试验研究了不同添加比例的生物柴油(BTL)混合燃料对高压共轨柴油机瞬变工况下微粒排放的影响,分析了不同瞬变率工况下微粒粒度分布特征,揭示了燃料理化特性对柴油机瞬态工况微粒排放粒度分布的影响规律。研究结果表明:瞬态工况下石化柴油、生物柴油燃料微粒粒数排放均呈双峰结构,核态微粒峰值在10nm附近,积聚态微粒峰值在60nm附近;石化柴油燃料微粒排放以大粒径积聚态微粒为主,占微粒总数的55%以上;BTL燃料微粒排放以小粒径核态微粒为主,占微粒总数的96%以上。随着工况瞬变率的减小,BTL燃料、石化柴油微粒平均数量排放均逐渐减少,BTL燃料下降更明显;石化柴油核态微粒排放受瞬变率的影响较为显著,BTL燃料受瞬变率的影响不明显。对于不同添加比例的生物柴油混合燃料,在小瞬变率工况,微粒排放数量随添加比例的增加缓慢上升;在中等瞬变率工况,添加比小于30%时微粒排放数量基本不增加,但核态微粒所占比例略有上升;在高瞬变率工况,添加比例大于10%时微粒排放数量大幅度上升。     

生物柴油/甲醇混合燃料对柴油机性能与排放的影响研究

在一台4缸直喷式柴油机上研究了超低硫柴油、生物柴油及后者与甲醇的混合燃料对发动机性能、气体及微粒排放的影响。生物柴油由餐饮废油制取,除单独使用外和甲醇按体积比90：10和80：20混合后使用。在最大扭矩转速1800 r.m in-1时,在5个不同负荷下,比较了不同燃料热效率及CO、HC、NOx以及微粒质量浓度,微粒的总数量及平均几何粒径。结果表明,和超低硫柴油相比,生物柴油及其和甲醇的混合燃料的热效率增加,NOx和微粒质量、数量浓度的排放降低,但HC、CO和NO2排放升高;同时,随着甲醇混合比例的增加,HC、CO和NO2的排放成比例增加,微粒的质量浓度及数量浓度进一步降低,热效率及NOx几乎保持不变。     

生物柴油燃料对柴油机不同负荷工况微粒粒度分布的影响

利用TS13090 EEPS微粒粒度测试系统,试验研究了生物柴油、石化柴油燃料微粒稳态工况下的粒度分布特征.研究结果表明,高压共轨柴油机微粒排放粒径绝大部分在300 nm以下,生物柴油、石化柴油燃料微粒粒度分布均呈双峰结构,核态蜂值区域在10 nm附近,积聚态峰值区域在60 nm附近.生物柴油燃料微粒排放以小粒径核态微...     

生物柴油在柴油机中的应用研究

本文简要介绍了生物柴油在国内外发展现状,并以正和生物柴油为燃料,以4102QBZ增压柴油机为研究对象,进行了纯生物柴油和生物柴油与柴油的混合燃料在柴油机中应用的试验研究。试验结果表明：在柴油机不进行任何调整的情况下,燃用生物柴油能保证柴油机的动力性不变,并明显降低柴油机微粒、烟度、HC和CO排放,是一种理想的替代燃料。     

柴油机燃用生物柴油的非常规气态排放试验研究

通过FTIR技术,对燃用混合不同比例的棉籽生物柴油的柴油机的气态非常规排放物进行了在线测量,对生物柴油排放的二氧化硫、醛类、苯类进行了分析。试验结果表明,生物柴油能够降低柴油机二氧化硫的排放;生物柴油对柴油机的气态醛类排放和苯类排放无明显影响,说明较低比例生物柴油的添加不增加柴油机气态排放的毒性。     

基于尺寸分布的生物柴油排气微粒组分研究

使用电子低压撞击仪(ELPI)分级粒径采集了柴油机的排气微粒,应用热重分析(TGA)方法研究了发动机燃用柴油和两种生物柴油时,排气微粒中挥发性物质(VOF)的含量。研究结果表明:燃用生物柴油,排气微粒VOF含量高于纯柴油,排气中小粒径微粒的VOF质量百分比均高于柴油,与总微粒的排放规律相同;超细微粒(d<0.100μm)具有较高的VOF质量百分比。柴油机燃用生物柴油后,总微粒中VOF质量百分比从44.917%上升到70.767%,在0.100μm相似文献   

非直喷式增压柴油机燃用生物柴油的性能与排放特性

研究了非直喷式增压柴油机燃用柴油一生物柴油混合燃料的性能和排放特性。未对原机作任何调整和改动,研究了不同生物柴油掺混比例的混合燃料对功率、油耗、烟度和NOx排放的影响。结果表明：非直喷式柴油机燃用生物柴油后柴油机功率略有下降,油耗有所上升,烟度大幅下降,NOx排放增加明显。油耗、烟度和NOx的变化均与生物柴油掺混比例呈线性关系,合适的生物柴油掺混比例即可以保持柴油机的性能,又可有效地降低碳烟排放,且不引起NOx排放的显著变化。对于该增压柴油机,掺混生物柴油对外特性下的排放影响最大,影响最小的为标定转速下的负荷特性。不论是全负荷还是部分负荷,燃用生物柴油时低速下的烟度降低和NOx上升幅度均比高速时大,而同转速下高负荷时烟度降低和NOx上升更为明显。     

生物柴油在非道路用柴油机上的实验研究

本文以非道路用186FA柴油机为研究对象,进行了生物柴油和0#轻质柴油经济性、排放性能对比实验。实验结果表明,186FA柴油机不需要改装就可以使用生物柴油。柴油机燃用两种燃油时,相同的功率条件下,生物柴油热效率提高。燃用生物柴油有利于降低CO、HC、颗粒,但是NOx排放会增加。生物柴油在非道路用柴油机上有广阔的应用前景。     

降低小型柴油机排放的试验研究

从生物混合燃料成分、燃烧室结构和排气再循环等方面探索降低柴油机排放的方法。通过对柴油机排放性能的大量试验研究,结果表明:对于直喷式柴油机,生物混合燃料的NOx排放与柴油的排放基本相当,碳烟排放则比柴油有较大幅度的降低,而涡流室柴油机,NOx的排放量却有大幅度的降低,碳烟排放则比直喷式柴油机有更大幅度的降低,生物燃料的添加比例对NOx的排放影响不大。柴油机采用排气再循环技术后,混合燃料的碳烟排放仍比柴油少,混合燃料可以承载一定的EGR率而不增加碳烟排放。排气再循环可以大幅度地降低NOx排放且与EGR率有关,与燃料的性质关系不大。涡流室柴油机采用生物燃料和排气再循环,可以同时降低NOx和碳烟的排放,排放效果非常优良。     

Determination of ecological efficiency in internal combustion engines: The use of biodiesel

This paper evaluates and quantifies the environmental impact from the use of some renewable fuels and fossils fuels in internal combustion engines. The following fuels are evaluated: gasoline blended with anhydrous ethyl alcohol (anhydrous ethanol), conventional diesel fuel, biodiesel in pure form and blended with diesel fuel, and natural gas. For the case of biodiesel, its complete life cycle and the closed carbon cycle (photosynthesis) were considered. The ecological efficiency concept depends on the environmental impact caused by CO₂, SO₂, NO_x and particulate material (PM) emissions. The exhaust gases from internal combustion engines, in the case of the gasoline (blended with alcohol), biodiesel and biodiesel blended with conventional diesel, are the less polluting; on the other hand, the most polluting are those related to conventional diesel. They can cause serious problems to the environment because of their dangerous components for the human, animal and vegetable life. The resultant pollution of each one of the mentioned fuels are analyzed, considering separately CO₂, SO₂, NO_x and particulate material (PM) emissions. As conclusion, it is possible to calculate an environmental factor that represents, qualitatively and quantitative, the emissions in internal combustion engines that are mostly used in urban transport. Biodiesel in pure form (B100) and blended with conventional diesel as fuel for engines pollute less than conventional diesel fuel. The ecological efficiency for pure biodiesel (B100) is 86.75%; for biodiesel blended with conventional diesel fuel (B20, 20% biodiesel and 80% diesel), it is 78.79%. Finally, the ecological efficiency for conventional diesel, when used in engines, is 77.34%; for gasoline, it is 82.52%, and for natural gas, it is 91.95%. All these figures considered a thermal efficiency of 30% for the internal combustion engine.     

Analysis of blended fuel properties and engine performance with palm biodiesel–diesel blended fuel

Depleting fossil fuel sources accompanied by continuously growing energy demands lead to increased interest in alternative energy sources. Blended biodiesel–diesel fuel has been approved as a commercial fuel at a low blending ratio. However, problems related to fuel properties are persistent at high blending ratios. Hence, in this study, the feasibility of biodiesel produced from palm oil was investigated. Characterization of blended fuel properties with increasing palm biodiesel ratio is conducted to evaluate engine performance test results. The qualifying of blended fuel properties was used to indicate the maximum blending ratio suitable for use in unmodified diesel engines according to the blended fuel standard ASTM D7467. The property test results revealed that blended fuel properties meet blended fuel standard requirements at up to 30% palm oil biodiesel. Furthermore, blending is efficient for reduction of the pour point from 14 °C for unblended biodiesel to less than 0 °C at a 30% biodiesel blending ratio. However, the energy content reduces by about 1.42% for each 10% increment of biodiesel. Engine test results demonstrated that there was no statistically significant difference for engine brake thermal efficiency among tested blended fuels compared to mineral diesel, and the lowest engine cyclic variation was achieved with blended fuel B30.     

大豆生物柴油混合燃料性能试验研究

通过在R4105T柴油机上进行对比试验,分析了0#柴油／生物柴油、乙醇／生物柴油混合燃料以不同比例掺混时对柴油机动力性、经济性及碳烟排放特性的影响。研究结果表明：柴油机使用0#柴油／生物柴油混合燃料时动力性、碳烟排放量均有所下降,油耗率稍有上升;使用乙醇／生物柴油混合燃料时,碳烟排放量低于生物柴油,动力性、经济性随乙醇含量的不同而呈现不同的变化趋势。     

Study on combustion characteristics and particulate emissions of a common-rail diesel engine fueled with n-butanol and waste cooking oil blends

Biodiesel is a promising alternative fuel because of its renewability and extensive source of raw materials. Butanol can be blended in biodiesel to reduce the kinematic viscosity and promote the fuel atomization. In this respect, biodiesel was blended with 10% and 20% n-butanol, and the combustion characteristics and particulate emissions of the fuel blends were tested in a turbocharged, 6-cylinder, common rail diesel engine at a constant speed of 1400 rpm under seven engine loads. The experimental results show that under various engine loads, all of the butanol and biodiesel fuel blends provide faster combustion than diesel due to the higher oxygen content of n-butanol and the lower cetane number of butanol which results in stronger premixed combustion. The addition of butanol is beneficial to concentrating the heat release and thus shorten the combustion duration. With an increased proportion of butanol, soot emissions of butanol and biodiesel fuel blends decrease, the number concentration and volume concentration of ultrafine particles (UFPs) reduce noticeably. Meanwhile, the geometric mean diameters of UFPs decrease with an increase in butanol. With an increase of the engine loads, the number concentration peaks of UFPs gradually transfer from the size range of nucleation mode particles (NMPs) to the size range of accumulation mode particles (AMPs) due to the elevated combustion temperatures and high equivalence ratios. Moreover, biodiesel and fuel blends exhibit a higher percentage of NMPs as compared to diesel because of the fuel-bound oxygen, zero aromatics, and low sulfides.     

The effect of biodiesel oxidation on engine performance and emissions

Biodiesel is an alternative fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats. Previous research has shown that biodiesel-fueled engines produce less carbon monoxide, unburned hydrocarbons, and particulate emissions compared to diesel fuel. One drawback of biodiesel is that it is more prone to oxidation than petroleum-based diesel fuel. In its advanced stages, this oxidation can cause the fuel to become acidic and to form insoluble gums and sediments that can plug fuel filters. The objective of this study was to evaluate the impact of oxidized biodiesel on engine performance and emissions. A John Deere 4276T turbocharged DI diesel engine was fueled with oxidized and unoxidized biodiesel and the performance and emissions were compared with No. 2 diesel fuel. The neat biodiesels, 20% blends, and the base fuel (No. 2 diesel) were tested at two different loads (100 and 20%) and three injection timings (3° advanced, standard; 3° retarded). The tests were performed at steady-state conditions at a single engine speed of 1400 rpm. The engine performance of the neat biodiesels and their blends was similar to that of No. 2 diesel fuel with the same thermal efficiency, but higher fuel consumption. Compared with unoxidized biodiesel, oxidized neat biodiesel produced 15 and 16% lower exhaust carbon monoxide and hydrocarbons, respectively. No statistically significant difference was found between the oxides of nitrogen and smoke emissions from oxidized and unoxidized biodiesel.     

Exhaust emission study on neat biodiesel and alcohol blends fueled diesel engine

In this study, neat biodiesel with octanol additive was employed in a diesel engine and its effects on engine emission were studied. The five fuels evaluated were neat palm kernal oil biodiesel, octanol blended with biodiesel by 10%, 20%, and 30% volume, and diesel. All the emissions are reduced by the addition of octanol in biodiesel in all loads owing to the higher oxygen concentration of air/fuel mixtures and improved atomization. Hence, it is concluded that the neat biodiesel and octanol blends can be employed as an alternative fuel for existing unmodified diesel engines owing to its lesser emission characteristics.     

Improving the low temperature properties of biodiesel fuel

The use of biodiesel as a diesel fuel extender and lubricity improver is rapidly increasing. While most of the properties of biodiesel are comparable to petroleum based diesel fuel, improvement of its low temperature flow characteristic still remains one of the major challenges when using biodiesel as an alternative fuel for diesel engines. The biodiesel fuels derived from fats or oils with significant amounts of saturated fatty compounds will display higher cloud points and pour points. This paper is aimed to investigate the cold flow properties of 100% biodiesel fuel obtained from Madhuca indica, one of the important species in the Indian context. In this paper, the cold flow properties of biodiesel were evaluated with and without pour point depressants towards the objectives of identifying the pumping and injecting of these biodiesel in CI engines under cold climates. Effect of ethanol, kerosene and commercial additive on cold flow behavior of this biodiesel was studied. A considerable reduction in pour point has been noticed by using these cold flow improvers. The performance and emission with ethanol blended Mahua biodiesel fuel and ethanol–diesel blended Mahua biodiesel fuel have also been studied. A considerable reduction in emission was obtained. Ethanol blended biodiesel is totally a renewable, viable alternative fuel for improved cold flow behavior and better emission characteristics without affecting the engine performance.     

Environmental effect of CeO2 nanoadditive on biodiesel

The role of additives for biodiesel has gained most reliable position in the current scenario as they reasonably formulate base fuel composition that contribute to efficiency reliability and long life of an engine. They also can have surprisingly large effects even when used in low (ppm) range. With the use of fuel additives for blending the biodiesel in compression ignition engine, one can expect diminished engine exhaust emission characteristics and also improved fuel properties, which could enhance the combustion characteristics. There are many reports based on the biodiesel blended with nanoparticles additive; however, there is a vacuum in the research pertaining to the use of the most common, low-cost, and eco-friendly CeO₂ nanoparticles as additive to prepare blended canola biodiesel fuel. Moreover, there are very few literatures available on the usage of CeO₂ blended biodiesel. In the present study, an attempt has been made to reduce and understand the engine emission of biodiesel blended with CeO₂ nanoparticles.