科创中国

Through an experiment conducted on the NO_x emission behavior from CA6DE1-21K diesel engine under transient operating conditions, it is investigated that under constant speed increasing torque transient operating conditions, NO_x emission is lower than that under static operating conditions, and torque increasing rate does not have obvious effect on NO_x emission. Under constant torque increasing speed transient operating conditions, NO_x emission increases with the growth of engine speed increasing rate (n) for low loads, and n do not have obvious effect on NO_x emission under high load conditions.

Zhong Chang Liu;Zhong Shu Wang;骏 李;Wen Xi Li

Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology

2004-6

Developed control algorithm for series hybrid electric power train is presented systematically, which keeps engine operation points on the locus of highest efficiency torque/speed points using a lookup table defined by engine power and speed. The off-line simulation model of series hybrid power train is developed which includes sub-models of control system and controlled objective (such as engine, motor, battery pack and so on). The debug and validation of control algorithm is performed on developed modular test facility. The results show that developed control algorithm can effectively keep engine operating on the locus of high efficiency points and much more fuel economy can be achieved than that of conventional ICE power train, meanwhile battery SOC can be maintained within reasonable level without charging outside during cycles.

亮 初;Qingnian Wang;Minghui Liu;骏 李

SAE Technical Papers

2003

The purpose of this study is to control lubricating oil consumption and PM emission through improving the adoption of round cooling jackets, larger countersunk head of cylinder cover, PT horning of liner, new design and materials of piston rings and stronger cooling to upper cylinder in CA6DF series engines. The test results show that lubricating oil consumption can be decreased greatly, the ratio of lubricating oil consumption to fuel consumption decreased from 0.3%-0.4% to less than 0.15%, and PM decreased by 79.5%. The study also indicates that reliability of engines increased.

Wen Xiang Li;Yun Shan Ge;骏 李;Peng Li;Fang Hu;Jin Wu Wang

Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering

2004-12

In concept design and prototype development of parallel hybrid power train for transit bus one of the main concerns is to determine the appropriate parameters of power train components. Utilizing the developed off-line simulation model of parallel hybrid power train the study on the influence of components' parameters on acceleration performance and fuel economy of transit bus is completed. Based on these the guideline strategies of parametric design of parallel hybrid power train for transit bus are brought forward in this paper. Given the condition of propulsion requirement the parametric design for this transit bus are performed targeting minimizing fuel consumption. It is conclusion that the appropriate components' parameters determined by means of parametric design can make parallel hybrid transit bus achieve much better acceleration performance and much lower fuel equivalent consumption than that of baseline transit bus.

亮 初;Qingnian Wang;Minghui Liu;骏 李

2004

The effects of temperature field and the substrate average temperature on the three way catalyst (TWC) conversion efficiency under different engine operations were studied on the test rig to analyze its mechanism. The experimental results showed that the temperature difference caused by the chemical reaction, heat and mass transfer in substrate is up to 82 °C. The factor which decides the catalytic process under different substrate average temperature is different, leading the distinct trend of conversion efficiency. All these provides the experimental basis for TWC design and effective calibration between engine and TWC.

Ying Gao;Xiu Min Yu;骏 李;Shi Chun Yang

Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition)

2006-7

Heavy duty diesel engine cylinder head crack is one of the main problems which affects engine durability. With the increasing requirements for better engine performance, less exhaust emission and lower fuel consumption, increased combustion pressure and elevated temperature make the engine cylinder head to be the most complicated and critical part for the engine design. The objective of this study was to apply cylinder head TMF simulation method to improving cylinder head structure and increasing its TMF life. Machined samples of gray cast iron (GJL 250) taken from cylinder head were used in material tests and material properties under different temperature were obtained from the tests. The finite element model of the whole assembled engine cylinder head/block was built and stress-strain curve were gained by cylinder head cold-hot cycle simulation. Then, cylinder head TMF life was calculated and different life prediction approaches were compared with each other and also with test results. Simulation and test results were generally in good agreement. The position of minimum TMF life from Ostergren approach, which considers mean stress effect, agree quite well with the early crack position of the cylinder head. By optimizing the cylinder head structure, TMF life of the cylinder head was greatly increased. Design standards, the best ratio between valve diameter and the distance of valve centers, maximum valve angle and optimized cylinder head wall, were set for the design of cylinder head of gray cast iron. Based on the creation of the whole assembled FE model of engine cylinder head/block and the application of the cold and hot cycle analysis and life prediction, TMF life of gray cast iron cylinder head were guaranteed at engine early development stage, and time and cost were saved.

骏 李;Pengcheng Wang;Xiaojuan Cui;Kang Li;Rentao Yi

2013

By the application of life cycle assessment (LCA) methodology, this paper estimates the environmental impacts of production and disposal of traction motors used in electric vehicles in China. The results show that the total energy use, the criteria emissions and the greenhouse gases (GHG) emissions of a traction motor production and disposal are about 2,899,MJ, 4.5,kg and 259.5,kg per motor, respectively. Among the regulated emissions, the SO _x emission ranks first by total mass, followed by CO, PM10, NO _x, PM2.5, and volatile organic compound (VOC). The motor material production stage accounts for most of the energy consumption and emissions, followed by the assembly stage and the end-of-life disposal stage. In this study, the environmental performance analysis is extended to the comparison between the use of secondary material and primary material for the material production stage. It is found that using 100% secondary material results in a 52.9% reduction in energy consumption, a 49.8% reduction in regulated emissions, and a 49.3% reduction in GHG emissions compared with the use of 100% primary material.

Shuhua Li;骏 李;Nannan Li;Qiang Lu;Dafu Tong;Ying Gao

Transactions of Tianjin University

2013-12

The combustion characteristics of a 2.0 L gasoline direct injection (GDI) engine were studied at the engine's medium and low speeds and part load operation conditions, and compared with that of PFI engine. The effects of port tumble ratio on GDI engine's combustion characteristics were also analyzed. The results show that, with the same engine compression ratio and operation condition of 2000 r/min, 0.2 MPa brake mean efficient pressure, the combustion velocity of GDI engine is slower than that of PFI engine. At the engine's medium and low speeds, increasing inlet port tumble ratio can enhance airflow intensity and combustion velocity. However, when engine speed increases to 3 000 r/min, big tumble ratio deteriorates combustion in cylinder. The flap added to the inlet port can increase the air flow velocity and the combustion process of the fuel air mixture at engine low speed conditions, so that improve the engine's low speed thermal efficiency. The CFD results of 2000 r/min, 0.2 MPa BMEP condition show that closing the inlet flap can intensify the in cylinder air flow and increase the uniformity of fuel air mixture.

骏 李;Yanfeng Gong;Wei Li;Hai'e Chen;Jinyu Liu;Jincheng Li;Kang Li;Huili Dou

Hsi-An Chiao Tung Ta Hsueh/Journal of Xi'an Jiaotong University

2010-7

A current-sensorless control method was proposed to apply in the vehicle drive motor to alleviate the shortecomings of the traditional vector control (narrow efficient work area) and the feedback loop control (being liable to over current). This method directly controls the magnitude and phase angle of the voltage vector according to the command motor torque and speed to realize the control of the real torque and speed of the motor. The proposed method saves the cost of the current sensor, avoids the dependence on the current sensor, the possible over current of the close loop control, and being unable to control under the condition of the current sensor malfunction. The simulation and bench test results show that the proposed method can not only increase the efficient work area, but also improve the reliability of the motor control system.

Ya Fu Zhou;Xiao Yong Shen;Jing Lian;骏 李;Ming Hui Liu;Zi Liang Zhao

Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition)

2012-1

In-cylinder flow and combustion characteristics of natural gas engine with bathtub combustion chamber were analyzed, two optimization schemes were proposed and performance of engine was studied when original combustion chamber and squish-injection combustion chamber were adopted. The results show that changing shape of piston head can achieve coupling between swirl and squish flow for constant compression ratio, control gas velocity near spark plug, increase mean turbulent kinetic energy, extend area of flame front and then improve combustion quality. Test was carried out at conditions of wide-open throttle and different speed to determine the effect of piston geometry on the performance and emissions. It shows that 2# chamber can accelerate speed of combustion greatly and improve power performance and fuel economy of engine. Power increases from 75 kW to 78.7 kW, fuel consumption decreases by 4.4%, HC and CO emissions decrease slightly.

Liping Yang;Xiuzhen Ma;Haiguo Jing;骏 李

Zhongguo Jixie Gongcheng/China Mechanical Engineering

2013-11-10