IGNITION DELAY AND SOOT EMISSION CHARACTERISTICS OF METHANOL-DIESEL FUEL BLENDS

Alcohols, as alternative fuels, may contribute to the solution of environmental and economical problems to a certain extend. But, they seem to have little chances to be directly used in Diesel engines because of their low cetane number. However, as blended fuels with diesel fuel they have places on the application area. In this study, the effect of the compression ratio on ignition delay and soot emission for methanol-diesel fuel blends with various blending ratios is investigated on an ASTM-CFR engine and the results are compared with baseline diesel fuel. Longer ignition delays and less soot emissions have been obtained for blend fuels as compared to diesel fuel.     

IGNITION DELAY CHARACTERISTICS OF SOME TURKISH VEGETABLE OIL-DIESEL FUEL BLENDS

Vegetable oils have chances to be used in Diesel engines as alternative fuels contributing to the solution of some agricultural, environmental and economical problems. Direct use of them has some technical problem yet but as blended fuels with diesel fuel or esters they have places on the application area. In this paper the effect of the compression ratio on ignition delay is investigated in an ASTM-CER engine working with four different types of vegetable oil of Turkish origin (sunflower, corn, soybean, and olive oil) blended with grade No.2-D diesel fuel at a ratio of 20/80 (v/v) and the results are compared with baseline diesel fuel. Longer ignition delay periods have generally been obtained for blend fuels ranking from olive oil to sunflower oil as compared to diesel fuel.     

IGNITION DELAY CHARACTERISTICS OF SOME TURKISH VEGETABLE OIL-DIESEL FUEL BLENDS

ABSTRACT

Vegetable oils have chances to be used in Diesel engines as alternative fuels contributing to the solution of some agricultural, environmental and economical problems. Direct use of them has some technical problem yet but as blended fuels with diesel fuel or esters they have places on the application area. In this paper the effect of the compression ratio on ignition delay is investigated in an ASTM-CER engine working with four different types of vegetable oil of Turkish origin (sunflower, corn, soybean, and olive oil) blended with grade No.2-D diesel fuel at a ratio of 20/80 (v/v) and the results are compared with baseline diesel fuel. Longer ignition delay periods have generally been obtained for blend fuels ranking from olive oil to sunflower oil as compared to diesel fuel.     

新油耗与排放法规下汽油发动机技术及对燃油的要求

阐述了我国油耗与排放法规的发展、现状与下一阶段的实施计划,从而探究在新油耗与排放法规下,汽油发动机技术、排放后处理技术的发展,及新技术的应用。通过多批次满足国Ⅳ和国Ⅴ排放标准汽油燃油的检测,分析了国Ⅴ排放标准实施后,汽油主要指标馏程、芳烃含量和蒸气压等发生的变化,阐明这些指标对汽油发动机和排放后处理新技术的影响,提出了汽油发动机技术对燃油的要求。结果表明,国Ⅴ排放标准实施后,汽油存在组分重、芳烃含量高、冬季蒸气压偏低等问题。在汽油发动机和排放后处理新技术应用下,这些问题会影响发动机的正常运行,同时导致车辆油耗的升高和排放恶化。因此,改善车辆油耗与排放,要求严格控制燃油指标,提升燃油品质。     

THE IMPORTANCE OF PYROLYSIS IN DIESEL IGNITION OF RESIDUAL FUEL OILS

Recent attempts to increase yields of distillate fuels from crude oil have resulted in a decline in the ignition quality of residual fuel oils and claims of ignition problems in large marine Diesel engines. This has revived an interest in fundamental studies of the ignition of liquid fuels and in new ways of defining and measuring ignition quality.

As part of an extensive study of the ignition of a range of residual fuels oils and during the development of novel teats of ignition quality it became obvious that thermal cracking of the fuel could play an important part in the pre-ignition chemistry. This paper reports kinetic data from simple experiments performed on the pyrolyses of residual fuel oils. Small samples and high heating rates were used to try to match the conditions inside a Blow-speed Diesel engine. This data has been used to assess the contribution that thermal cracking makes to ignition processes.

Pyrolyses were carried out on a small silica-coated platinum coil in the inlet of a gas chromatograph. Light hydrocarbon pyrolysis products were formed, and the extent and rate of cracking determined at four temperatures.

Assuming that reaction took place on a surface surrounding the oil and that a constant supply of reactants were available, pseudo zero order rate constants for the initial part of the reaction were evaluated. They showed an Arrhenius relationship with temperature giving an overall apparent activation energy of 110 kJ mol^-1. Extrapolating rate constants to temperatures expected in Diesel engines, and assuming typical droplet sizes end ignition delays, it was shown that thermal cracking of fuels was possible before ignition and that it is likely that these reactions will have a strong influence on the processes leading to ignition. It was also shown that the presence of oxygen greatly increases the rate of thermal cracking.     

THE IMPORTANCE OF PYROLYSIS IN DIESEL IGNITION OF RESIDUAL FUEL OILS

ABSTRACT

Recent attempts to increase yields of distillate fuels from crude oil have resulted in a decline in the ignition quality of residual fuel oils and claims of ignition problems in large marine Diesel engines. This has revived an interest in fundamental studies of the ignition of liquid fuels and in new ways of defining and measuring ignition quality.

As part of an extensive study of the ignition of a range of residual fuels oils and during the development of novel teats of ignition quality it became obvious that thermal cracking of the fuel could play an important part in the pre-ignition chemistry. This paper reports kinetic data from simple experiments performed on the pyrolyses of residual fuel oils. Small samples and high heating rates were used to try to match the conditions inside a Blow-speed Diesel engine. This data has been used to assess the contribution that thermal cracking makes to ignition processes.

Pyrolyses were carried out on a small silica-coated platinum coil in the inlet of a gas chromatograph. Light hydrocarbon pyrolysis products were formed, and the extent and rate of cracking determined at four temperatures.

Assuming that reaction took place on a surface surrounding the oil and that a constant supply of reactants were available, pseudo zero order rate constants for the initial part of the reaction were evaluated. They showed an Arrhenius relationship with temperature giving an overall apparent activation energy of 110 kJ mol^-1. Extrapolating rate constants to temperatures expected in Diesel engines, and assuming typical droplet sizes end ignition delays, it was shown that thermal cracking of fuels was possible before ignition and that it is likely that these reactions will have a strong influence on the processes leading to ignition. It was also shown that the presence of oxygen greatly increases the rate of thermal cracking.     

燃气脉冲波吹灰器在CO锅炉上的应用

介绍燃气脉冲波吹灰器的系统构成、工艺原理及其在青岛石油化工有限责任公司的应用情况。针对应用中出现的问题采取了措施,效果明显:(1)由导焰管引起的烟气走廊得到了消除;(2)一次点火成功率达到90%以上;(3)过热器区域的早爆现象不再出现;(4)腐蚀问题得到了初步解决。     

燃气组分变化对重整燃烧器燃烧过程及炭粒生成的影响

采用数值模拟方法对连续重整加热炉燃烧器的流动和燃烧过程进行研究,分别考察氢气、甲烷、乙烷、丙烷和丁烷五种不同的气体燃料对燃烧过程的影响,重点研究在燃烧不同气体燃料时的燃烧状况和火焰形状的变化情况及形成原因,同时考察燃气组分变化对炭粒生成的影响。结果表明,较轻的燃料燃烧迅速,具有较短的刚直火焰,辐射段出口烟气温度较低,燃烧充分,炭粒生成较少;较重的燃料与空气混合慢,火焰较长,辐射段出口烟气温度较高,未完全燃烧的燃料在很大区域存在,炭粒生成较多,并可能形成结焦。     

汽车节能与排放控制技术进步及其对润滑油的要求

对以汽油机和柴油机为动力的汽车节能及排放控制技术进步进行了综述,这包括传统汽油机的主要技术、缸内直喷式汽油机的应用现状与技术难点、均质混合气压燃技术应用于汽油机的优势与研究进展、柴油机的机内净化技术以及柴油机的排气后处理技术。同时,简要讨论了这些技术进步和变化带来的对润滑油性能的新要求。     

点燃式发动机检测用油国家标准样品的研制

参照车用无铅汽油国内外相关标准,确定了点燃式发动机Ⅰ类、Ⅱ类检测用油技术性能指标,制定了文字标准,并以储量丰富、性质稳定的新疆混合原油生产的液体烃类调配制成了点燃式发动机检测用油国家标准样品,经过测试,该样品均匀性良好且在有效期内性质稳定,可作为汽车发动机匹配的标定试验用标准样品和仲裁用汽油。     

支持燃油汽车低碳和污染物超低排放的高效高清洁汽柴油标准

分析了电动汽车、氢燃料电池汽车在未来发展过程中面临的挑战,油电混合动力汽车在节油减碳和尾气中污染物超低排放中的作用,提出未来较长时间内汽车动力会呈现电、氢、油共存的格局。针对未来汽柴油的市场需求,提出炼油企业要致力开发高效高清洁汽柴油,支持燃油汽车实现低碳和污染物超低排放。综合国际、国内进行的油品质量对污染物及碳排放影响的研究结果和国外主要汽车制造商对未来油品质量指标的诉求,对我国高效高清洁汽柴油的主要技术指标、标准制定研究、主要技术开发课题及推进策略提出了具体建议。     

PREPARATION CHARACTERISTICS OF CATALYSTS FOR FOSSIL FUEL CONVERSION

The article reviews some of the technical Intricacies which are Involved In the preparation of metal oxide containing catalysts. In processing of energy resources, representative reactions catalysed by metal oxides Include cracking, reforming, hydrofining, water-gas shift, and methanol synthesis. The preparatory methods of metal catalysts control the selectivity, stability and activity for a particular reaction.

The specifics of the technique of preparation and the chemical nature of a catalyst control the main stream of chemical products and the duration of continuous operation of reactors. The nature of metal-support plays an important role, other than to stabilize the small particles of the metal. Certain supports like zeolites, polymers, reducible oxides modify drastically the catalytic properties of metals. Addition of an inactive additive to a metal catalyst produces a large effect on both catalytic activity and resistance to poisoning of the pure metal. A defined porous structure, the size of the Internal surface and the mechanical strength are the additional criteria on which the success of the art of catalyst preparation depends.     

PREPARATION CHARACTERISTICS OF CATALYSTS FOR FOSSIL FUEL CONVERSION

ABSTRACT

The article reviews some of the technical Intricacies which are Involved In the preparation of metal oxide containing catalysts. In processing of energy resources, representative reactions catalysed by metal oxides Include cracking, reforming, hydrofining, water-gas shift, and methanol synthesis. The preparatory methods of metal catalysts control the selectivity, stability and activity for a particular reaction.

The specifics of the technique of preparation and the chemical nature of a catalyst control the main stream of chemical products and the duration of continuous operation of reactors. The nature of metal-support plays an important role, other than to stabilize the small particles of the metal. Certain supports like zeolites, polymers, reducible oxides modify drastically the catalytic properties of metals. Addition of an inactive additive to a metal catalyst produces a large effect on both catalytic activity and resistance to poisoning of the pure metal. A defined porous structure, the size of the Internal surface and the mechanical strength are the additional criteria on which the success of the art of catalyst preparation depends.     

MODELING AND SIMULATION OF SPARK IGNITION ENGINES

ABSTRACT

Modeling is important because it saves time, effort and cost needed for engine development and prediction of performance. In this work, losses due to imperfect construction of the real engine, including progressive combustion, valve timing and heat transfer have been modeled besides engine friction. Hence, it becomes possible to convert the output of the fuel-air cycle into net brake performance. Simulation of engine performance was carried out by varying engine speed, compression ratio and spark advance over wide range. Hence, it was possible to compare the results with those from experiments on a single cylinder engine. The model predictions were found to compare favourably with experiment within 4·6% in power and 2·9% in SFC. The losses considered in this work amount to about 14% of the fuel energy input.     

MODELING AND SIMULATION OF SPARK IGNITION ENGINES

Modeling is important because it saves time, effort and cost needed for engine development and prediction of performance. In this work, losses due to imperfect construction of the real engine, including progressive combustion, valve timing and heat transfer have been modeled besides engine friction. Hence, it becomes possible to convert the output of the fuel-air cycle into net brake performance. Simulation of engine performance was carried out by varying engine speed, compression ratio and spark advance over wide range. Hence, it was possible to compare the results with those from experiments on a single cylinder engine. The model predictions were found to compare favourably with experiment within 4·6% in power and 2·9% in SFC. The losses considered in this work amount to about 14% of the fuel energy input.     

纳米CeO2柴油添加剂制备及改善内燃机节油与排放性能研究

使用油溶性水杨醛亚胺化合物先与三氯化铈配位,再结合超重力反应工艺,得到了粒径小、分布窄,且在油中稳定分散的纳米二氧化铈（CeO2）微粒;以该纳米微粒的油分散体系为柴油添加剂,通过发动机台架（Phaser140Ti-E30型直列四缸发动机）试验考察加剂前后发动机负荷特性、速度特性及有害污染物排放等指标,结果表明,纳米CeO2柴油添加剂可使内燃机节油最高可达7%左右,同时降低了排放中的总碳氢化合物、颗粒物等有害物质及烟度。     

MODELING AND SIMULATION OF COMPRESSION IGNITION ENGINES

ABSTRACT

Modeling of a compression ignition engine was carried out covering losses emanent from imperfect construction of real engines such as progressive combustion, valve timing, and heat transfer. Furthermore, friction was included to obtain brake performance. Simulation of engine performance was tackled by varying engine speed, compression ratio and injection timing over wide range. The results were compared with those obtained from the experiemntal facility. Predictions by the model compare favourably with experiment within 9·3% and 9·7% for power and sfc respectively. The losses considered in this work amount to about 30% of the fuel energy input at the design point.     

MODELING AND SIMULATION OF COMPRESSION IGNITION ENGINES

Modeling of a compression ignition engine was carried out covering losses emanent from imperfect construction of real engines such as progressive combustion, valve timing, and heat transfer. Furthermore, friction was included to obtain brake performance. Simulation of engine performance was tackled by varying engine speed, compression ratio and injection timing over wide range. The results were compared with those obtained from the experiemntal facility. Predictions by the model compare favourably with experiment within 9·3% and 9·7% for power and sfc respectively. The losses considered in this work amount to about 30% of the fuel energy input at the design point.     

喷气燃料加抗静电剂后水分离指数下降原因及对策

对喷气燃料加抗静电剂后水分离指数严重下降的原因进行分析,确定影响因素为原料携带的碱性氮化物,提出提高低温加氢脱硫醇装置的反应温度至280 ℃或保持反应温度在240 ℃时采取白土吸附两项对策。采用两项对策后,均可以使喷气燃料加剂后水分离指数符合不低于70的质量要求。     

石油焦着火和燃烧燃烬特性的试验研究

用热重分析方法对石油焦的着火及燃烬特性进行研究 ,发现石油焦的着火温度随颗粒直径的增加和质量的减小而增加 ,石油焦的燃烬率随颗粒直径的减小、升温速率的减小和样品质量的减小而增加。石油焦的燃烧特性处于烟煤和无烟煤之间