On the way to 130 g CO2/km—Estimating the future characteristics of the average European passenger car

A new average CO₂ emissions limit for passenger cars was introduced in EU in 2009 imposing gradual average CO₂ emissions reduction to 130 g/km until 2015. This paper attempts to study possible changes in vehicle characteristics for meeting this limit taking into account the average European passenger car of 2007–2008. For this purpose first the most important factors affecting vehicle fuel consumption over the reference cycle (NEDC) are identified. At a second step, the CO₂ benefit from the optimisation of these factors is quantified, through simulations of 6 different passenger cars commonly found in the European fleet. For the simulations Advisor 2002 was employed and validated against published type approval data. The analysis indicated that substantial reductions in vehicle weight, tyre rolling resistance and engine efficiency are necessary to reach even the 2008 target. A 10% reduction in average vehicle weight combined with 10% better aerodynamic characteristics, 20% reduced tyre rolling resistance and a 7.5% increase in average powertrain efficiency can lead to CO₂ reductions of approximately 13% (about 138 g/km based on 2007–2008 fleet-wide performance). Complying with the 130 g/km within the next six-year timeframe will be a rather difficult task and additional technical measures appear to be necessary.     

Operating strategy for a hydrogen engine for improved drive-cycle efficiency and emissions behavior

Due to their advanced state of development and almost immediate availability, hydrogen internal combustion engines could act as a bridging technology toward a wide-spread hydrogen infrastructure. Extensive research, development and steady-state testing of hydrogen internal combustion engines has been conducted to improve efficiency, emissions behavior and performance. This paper summarizes the steady-state test results of the supercharged hydrogen-powered four-cylinder engine operated on an engine dynamometer. Based on these results a shift strategy for optimized fuel economy is established and engine control strategies for various levels of hybridization are being discussed. The strategies are evaluated on the Urban drive cycle, differences in engine behavior are investigated and the estimated fuel economy and NO_x emissions are calculated. Future work will include dynamic testing of these strategies and powertrain configurations as well as individual powertrain components on a vehicle platform, called ‘Mobile Advanced Technology Testbed’ (MATT), that was developed and built at Argonne National Laboratory.     

Modeling fuel efficiency for heavy duty vehicles (HDVs) in India

Transport sector accounts for almost 70% consumption of diesel in India. With increased dependency on road transportation for freight transport, there is a need to develop fuel-efficiency standards for the heavy duty vehicles (HDVs). This study models the fuel efficiency of the existing fleet of HDVs and compares it with the world’s best practices. The model uses the technical details of the existing HDV fleet and the prescribed driving cycles to assess fuel efficiency. The results of the model are validated with the actual test results of fuel efficiency observed for HDVs in India. The model presents a fuel economy of 2.65 km/l for truck and bus model of given specification. The validated model is then used for evaluating the potential of different strategies to improve fuel efficiency. The models estimate a potential of about 36% improvement in the fuel efficiency in the HDVs in India through improvements in thermal efficiency, reduction in rolling resistance, and reduction in vehicle weight. The study provides a direction for the possible fuel efficiency improvements in HDV sector in India.     

FAI二冲程缸内直喷汽油机的研究

基于AX～100二冲程化油器式发动机进行了FAI(Free Armature Injection自由电枢喷射)缸内直喷二冲程发动机的台架试验研究，在原机的基础上设计改造了一个适合缸内直喷的燃烧室结构，获得了大量的缸内直喷的试验数据和电控参数的MAP图，并做了该直喷发动机和原化油器发动机的性能、燃油消耗和HC排放的比较。结果表明，FAI直喷技术能够成功地应用于二冲程发动机缸内直喷系统，极大改善了燃油短路的现象和扫气效率，在整个运行范围内燃油消耗大大降低，HC排放改善很多。     

基于整车性能的重型车用发动机优化配置

以一款载重卡车动力总成选配为例,根据国家标准和实际使用状况,以动力性和经济性为评价目标,通过模拟计算和试验对可供选配的三款发动机进行匹配计算和分析。结果表明：样车配置A款发动机的性能优于B款发动机,而配置经改进后的B款发动机(C款)其性能有了明显的提高;若实现整车和发动机的同步开发,可以大幅提高整车的动力性、经济性。为整车动力总成优化和车用发动机的特性优化提供了可行的技术路线。     

A review on fuel economy standard for motor vehicles with the implementation possibilities in Malaysia

This paper focused on a review of international experiences on fuel economy standard based on technologies available. It also attempts to identify savings possibilities and greenhouse gas (GHG) emissions reductions. It is known that road transport, particularly private cars are responsible for large, and increasing share of transport fuel use and emissions. With the implementation of fuel economy standard and label for motor vehicles, it will reduce the risks of increasing dependency on petroleum-based fuel and will increase the profit to consumers. The GHG emissions, which causing global warming, air pollution, diseases, etc. can be reduced as well. In this regard, advanced technologies such as, engine, transmission, and vehicle technologies may brought significant consumers and social benefits. Studies in developed countries have shown that fuel economy standard is beneficial for the society, government as well as the environment.     

Comparison of the technical potential for hydrogen,battery electric,and conventional light-duty vehicles to reduce greenhouse gas emissions and petroleum consumption in the United States

Light-duty vehicles (LDV) are responsible for a large fraction of petroleum use and are a significant source of greenhouse gas (GHG) emissions in the United States. Improving conventional gasoline-powered vehicle efficiency can reduce petroleum demand, however efficiency alone cannot reach deep GHG reduction targets, such as 80% below the 1990 LDV GHG emissions level. Because the cost and availability of low-GHG fuels will impose limits on their use, significant reductions in GHG emissions will require combinations of fuel and vehicle technologies that both increase efficiency and reduce the emissions from fuel production and use. This paper examines bounding cases for the adoption of individual technologies and then explores combinations of advanced vehicle and fuel technologies. Limits on domestic biofuel production—even combined with significant conventional combustion engine vehicle improvements—mean that hydrogen fuel cell electric or battery electric vehicles fueled by low-GHG sources will be necessary. Complete electrification of the LDV fleet is not required to achieve significant GHG reduction, as replacing 40% of the LDV fleet with zero-emission hydrogen vehicles while achieving optimistic biofuel production and conventional vehicle improvements can allow attainment of a low GHG emission target. Our results show that the long time scale for vehicle turnover will ensure significant emissions from the LDV sector, even when lower emission vehicles and fuels are widely available within 15 years. Reducing petroleum consumption is comparatively less difficult, and significant savings can be achieved using efficient conventional gasoline-powered vehicles.     

Investigating the effects of LPG on spark ignition engine combustion and performance

A quasi-dimensional spark ignition (SI) engine cycle model is used to predict the cycle, performance and exhaust emissions of an automotive engine for the cases of using gasoline and LPG. Governing equations of the mathematical model mainly consist of first order ordinary differential equations derived for cylinder pressure and temperature. Combustion is simulated as a turbulent flame propagation process and during this process, two different thermodynamic regions consisting of unburned gases and burned gases that are separated by the flame front are considered. A computer code for the cycle model has been prepared to perform numerical calculations over a range of engine speeds and fuel–air equivalence ratios. In the computations performed at different engine speeds, the same fuel–air equivalence ratios are selected for each fuel to make realistic comparisons from the fuel economy and fuel consumption points of view. Comparisons show that if LPG fueled SI engines are operated at the same conditions with those of gasoline fueled SI engines, significant improvements in exhaust emissions can be achieved. However, variations in various engine performance parameters and the effects on the engine structural elements are not promising.     

发动机排气应用研究

根据驱动桥、变速箱润滑油温度与传动效率的关系,研究发动机排气加热变速箱和驱动桥润滑油对润滑油温度及热车时间的影响。设计排气利用装置,在动力总成试验台架上进行实际管路改造,进行等速油耗、综合工况油耗及动力总成预热等试验。试验结果表明,通过该方式整车综合油耗可以降低1.0%~1.5%,热车时间可减少50%。     

Simulation for the analysis of a hybrid electric scooter powertrain

This paper describes the mathematical modelling, analysis and simulation of a novel hybrid powertrain used in a scooter. The primary feature of the proposed hybrid powertrain is the use of a split power-system that consists of a one-degree-of-freedom (dof) planetary gear-train (PGT) and a two-dof PGT to combine the power of two sources, a gasoline engine and an electric motor. Detailed component level models for the hybrid electric scooter are established using the Matlab/Simulink environment. A simple rule-based power control strategy is then established with the primary objective to optimize the fuel economy of the hybrid electric scooter. The performance of the proposed hybrid powertrain is studied using the developed model under four driving cycles. The simulation results verify the operational capabilities of the proposed hybrid system and show both the engine and the electric motor work in an optimal state under various operating conditions.     

增压柴油机燃用不同掺比菜籽油甲酯的燃烧和排放的试验研究

在D6114ZLQB车用增压柴油机上比较研究了不同比例的菜籽油甲酯和0号柴油的混合燃料对发动机燃烧过程、燃油经济性和排放特性的影响。试验结果表明：燃用体积比低于15%的菜籽油甲酯,发动机的缸内燃烧过程和纯柴油基本一致;增压柴油机燃用菜籽油甲酯和柴油的混合燃料可以有效降低碳烟、HC和CO的排放;NOx排放略有上升;15%以内的菜籽油甲酯对柴油机燃料经济性影响很小。研究认为：增压柴油机相对自然吸气式柴油机具有更好的生物柴油燃料适应性;在不改变发动机参数的条件下,低比例的菜籽油甲酯具有良好的推广应用前景。     

二次喷油对点燃式可变滚流进气发动机稀燃影响的研究

利用二次喷油稀燃实验系统研究了二次喷油对可变滚流进气发动机稀燃特性的影响情况。首先，采用纯滚流可变滚流进气系统时，采用较大比例的二次喷油量可以获得更好的稀燃经济性。第二，最低油耗点所对应的喷油正时按照T1、T2和T3顺序依次提前；负荷较大时，对应的最低油耗点喷油正时也相应提前。第三，在可变滚流结构中，二次喷油可能造成局部混合气过浓．导致CO排放增加：同时．在稀燃情况下．增大滚流比可以降低发动机HC和NOχ排放。第四，增大滚流比可以改善发动机低速工况条件下的性能，但应避免机构对燃油喷注的阻隔作用。     

Design and numerical analysis of a 3 kWe flameless microturbine combustor for hydrogen fuel

In this work, a new 3 kWe flameless combustor for hydrogen fuel is designed and analyzed using CFD simulation. The strategy of the design is to provide a large volumetric combustion for hydrogen fuel without significant rise of the temperature. The combustor initial dimensions and specification were obtained from practical design procedures, and then optimized using CFD simulations. A three-dimensional model for the designed combustor is constructed to further analysis of flameless hydrogen combustion and consideration that leads to disappearance of flame-front and flameless combustion. The key design parameters including aerodynamic, temperature at walls and flame, NO_X, pressure drop, combustion efficiency for the hydrogen flame is analyzed in the designed combustor. To well demonstrate the combustor, the NO_X and entropy destruction and finally energy conversion efficiency, and overall operability in the microturbine cycle of hydrogen flameless combustor is compared with a 3 kWe design counterpart for natural gas. The findings demonstrate that hydrogen flameless combustion is superior to derive the microturbines with significantly lower NO_X, and improvements in energy efficiency, and cycle overall efficiency with low wall temperatures guaranteeing the long-term operation of combustor and microturbine parts.     

Model-based power control strategy development of a fuel cell hybrid vehicle

An integrated procedure for math modeling and power control strategy design for a fuel cell hybrid vehicle (FCHV) is presented in this paper. Dynamic math model of the powertrain is constructed firstly, which includes four modules: fuel cell engine, DC/DC inverter, motor-driver, and power battery. Based on the mathematic model, a power control principle is designed, which uses full-states closed-loop feedback algorithm. To implement full-states feedback, a Luenberger state observer is designed to estimate open circuit voltage (OCV) of the battery, which make the control principle not sensitive to the battery SOC (state of charge) estimated error. Full-states feedback controller is then designed through analyzing step responding of the powertrain and test data. At last of the paper, the results of simulation and field test are illustrated. The results show that the power control strategy designed takes into account the performance and economy characteristics of components of the FCHV powertrain and achieves the control object excellently.     

基于Cruise的客车动力总成匹配及仿真分析

介绍了运用AVL公司Cruise软件对客车动力匹配进行模拟计算。该软件将发动机、变速箱、后桥等影响整车动力性、经济性的相关因素整合成一整套动力总成系统。通过大量的实践证明,这种对于动力总成系统的优化,可以更好满足整车厂对于整车经济型和动力型的要求。     

汽油加入生物添加剂对发动机燃油经济性影响的研究

将一种热带植物中的提取物作为添加剂，加入现在市场上正使用的几种辛烷值为93^#的高清洁汽油、普通汽油、已知成分汽油和乙醇汽油。通过发动机台架试验对加剂前后的汽油机燃油经济性进行了对比和分析。结果表明：在典型城市道路工况下，加入此种添加剂后对各种汽油的燃油经济性有大幅改善作用，对乙醇汽油的效果更加明显。加剂后可以使乙醇汽油的燃油经济性与普通汽油相同。     

中速柴油机燃用重质燃料油的试验及数值模拟研究

以某型号大功率中速柴油机为研究对象,以燃烧性能试验和数值模拟方法研究了重质燃料油在该机上的燃烧性能、动力性能和燃油经济性。研究表明:与燃用轻柴油相比,在燃用重质燃料油时,柴油机保持了原有的动力性能;燃油消耗率有所上升,但考虑重质燃料油的低成本因素,其经济性有较大程度改善。为了进一步改善燃油经济性并保证燃用重质燃料油时柴油机的可靠性,对喷油嘴等燃油系统关键部件进行改进设计是必要的。     

基于重型并联混合动力车辆混合度的性能分析

动力系统的匹配直接关系到车辆的性能,在对混合动力车辆的研究中有着非常重要的地位,而混合度的研究是动力系统匹配中的关键.本文基于已选定的额定功率为220kw的柴油发动机,对混合动力车辆的电机进行匹配,对不同混合度下的车辆模型进行性能分析.通过Avl-Cruise软件对各混合度下的车辆模型进行仿真对比,选用等效油耗以及比排放量为评价指标,对不同混合度下混合动力车辆的性能进行了比较,研究了随着混合度的变化,车辆的经济性以及排放性能变化的规律,提出了适用于本混合动力系统的最佳混合度.     

Transition strategy of the transportation energy and powertrain in China

The problems of the transportation energy and environment are the major challenges faced globally in the 21st century and are especially serious for China. The future 20 years is the strategic opportunity period of the transition of the transportation energy and powertrain system for China. The greatest characteristics of hydrogen economy lie in its diversity of the primary energy source, the unification of energy carrier and the greening of energy transformation. Development of hydrogen energy transportation powertrain system is suitable for China from the views of the situation of Chinese resources and energy sources, the urban and rural layouts, the superiority of later development and the successful practices of clean cars and electric vehicle development projects. The transition of the transportation energy powertrain system includes three parts: the transition of the energy structure, the transition of the powertrain system and the transition of the fuel infrastructure. The technical pathways of energy powertrain system transition includes expending the use of gaseous fuel to prompt the multiform of the transportation energy and to prepare for the transition of the infrastructure simultaneously, developing and promoting the hybrid technology to solve the current energy and environment problems and to prepare for the transition of powertrain system, and focusing on the research and development and demonstration of fuel cell vehicles and the hydrogen energy technology to prompt the earlier formation of the market of fuel cell vehicles. The goal in the near and medium term of transition is to reduce the fuel consumption by 100 million ton in 2020 by substituting and saving, and the long-term goal is to setup the infrastructure of hydrogen and fuel cell vehicle as the main one replacing the petroleum internal combustion engine vehicle. In order to realize the strategic goals of the transition, the four-phases strategic periods and research and development activities are discussed and proposed.