科创中国

The plateau calibration is of importance in the development of common-rail diesel engine. The full load calibration experiment of common-rail diesel engine at different altitudes was conducted by high altitude (low air pressure), and the relationships between the optimal injection parameters and the altitude were investigated. Then, the power experiment at different altitudes was completed. Results show that the optimal fuel delivery per cycle per cylinder decreases with increasing altitude, which decreased by 2%-4% when the altitude increased by 1000 m. The optimal injection advance angle and common-rail pressure increase with increasing altitude within medium and high rotated speed ranges. The maximum torque and rated power decreased by 2.8% and 2.9%, respectively, with the altitude increasing by 1000 m. The speed coefficient of diesel remains unchanged at different altitudes. The fuel economy remains roughly unchanged at different altitudes within medium and high rotated speed ranges, but it experiences a deterioration at lower rotated speeds, which increased the specific fuel consumption by 3.9% with the altitude increasing by 1000 m.

Rui Lin Liu;Guang Meng Zhou;骏 李;Su Rong Dong;Ping Zhou;Fei Ge

Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology

2012-6

Combustion process of supercharged inter-cooled natural gas engine was studied using nonlinear dynamic data analysis technology under the conditions of equivalence ratio (φ) from 1.00 to lean burn limit. Results showed that motion trajectories of combustion system in 2-D reconstructed state space fell into a finite range at different conditions, there were complex, twist and wrap geometric structures in reconstructed state space. Correlation dimension (D) of attractors could reach saturation value after embedding dimension m was greater than a certain value when engine worked at both conditions of equivalence ratio mixture and lean burn limit, at the same time the values were fractional, with the decrease of mixture concentration, cycle-to-cycle combustion variations increased, D increased, the D of attractors were 1.27, 1.33, 1.58 and 1.87, Largest Lyapunov Exponent (LLE) were 0.0086, 0.011, 0.013 and 0.0157 respectively at the conditions of equivalence ratio φ=1.00, 0.77, 0.70 and 0.63, therefore the combustion system of natural gas engine was a low-dimension chaos system.

Liping Yang;Liyuan Wang;Xiuzhen Ma;骏 李

Nongye Jixie Xuebao/Transactions of the Chinese Society of Agricultural Machinery

2011-1

The error sources of state of charge (SOC) estimation algorithm on the basis of Kalman filter is analyzed in this paper. Aiming at the influence of the measuring precision of voltage and current in battery management system (BMS) to SOC estimation, a simulation analysis is performed independently in Simulink on the assumption that other factors are under ideal conditions, in which the effects of Gaussian white noise and the offset error of measurement of BMS are discussed respectively to simulate the actual vehicle condition. The principle to the precision index design of BMS is proposed according to the simulation result. At last, a high-precision data acquisition system is developed as a precise calibration benchmark device for BMS.

Tingting Dong;骏 李;Haifeng Dai

2010

In this paper, A heavy-duty NG engine and its electronic controlled system were developed. combustion stability, in-cylinder flow, burning rate and hazardous emissions were further investigated to develop optimized combustion control technologies for efficient and clean combustion on this engine. The electronic controlled system and NG supply system were designed in the condition of maintaining the universal parts of based diesel engine as many as possible. The combustion and emissions of NG engine were investigated by means of experiment and numerical simulation with the commercial 3D-CFD-tool STAR-CD. The in-cylinder flow and burning rate of NG engine were studied. Special-shaped combustion chamber was used to change the flow state. The results show that the engine thermal efficiency increases by 2 % compared with the original engine while using the cross-type rapid combustion chamber under 1450r/min,100 % load operating condition. Effect of three kinds of dilution methods on combustion and emissions performance from lean burn NG engine was investigated. These dilution methods include air dilution, stoichiometric combustion with EGR, and double dilution (extra air and EGR). The results show that double dilution method is superior to other methods no matter considering from fuel economy or NOx emissions.

Huili Dou;骏 李;Zhongshu Wang;Xiaocao Yu;Zhongchang Liu;Jingxue Li

2013

The working process of a gasoline direct injection engine, which was developed by the R&D Center of FAW Group, was simulated with 3-D CFD package. The movement of working fluid in the intake ports and cylinder of the engine was analyzed. The fuel injection and fuel-Air mixture formation processes of two injection strategies were compared and analyzed. The formation and development processes of tumble in cylinder were studied, and the influence of tumble on fuel-Air mixture formation was investigated. The fuel injection, fuel-Air mixture formation and combustion processes of two injection timings were compared. The results show that under the present condition, injection timing of SOI=420 °CA leads to better fuel-Air mixture quality around spark plug at the ignition time, and that is in favor of the ignition and the flame propagation.

Li Yan Feng;Chun Huan Zhang;Jiang Ping Tian;Wu Qiang Long;骏 李;Jin Cheng Li;Yan Feng Gong

2010

Due to the difficult cold start for LPG engine, most of LPG passenger cars adopt gasoline auxiliary start and automatically switch to LPG after engine warm-up. Therefore, the optimized fuel switch conditions are critical to the development of LPG passenger car meeting with National Emission IV legislation. This paper presents the effects of coolant temperature, engine speed and torque on the switch process by means of lots of experiments. The results show that they bring the transient fluctuation of excess air coefficient during switch process. Thus the fluctuation amplitude and duration have direct impact on engine tailpipe emission. If the excess air coefficient fluctuation amplitudes go beyond the high conversion efficiency window of three-way catalyst, the engine's transient emission deteriorates. Above all, the proper control of the excess air coefficient fluctuation amplitude is significant to lower engine emission during fuel switch process.

Gao Ying;Yonglei Fang;骏 李;Changji Zhu

2011

Logical control method is used for the position control of pneumatic clutch actuator of Automated Manual Transmission (AMT) trucks. The control input is the PWM duty ratio of 4 pneumatic valves, and the feedback signals are tracking displacement and velocity. By building the clutch model using software AMESim and then combined with MATLAB/Simulink through co-simulation, the control logic is calibrated. Finally, the well-tuned control law is used for experimental tests. Through the engagement and disengagement control under different conditions, the feasibility of the actuator control strategy is verified.

Zhan Jiang Li;Shu Li;Na Na Tang;骏 李

2014

To overcome the difficulty in the cold start of the spark-ignition (SI) methanol-fueled engine with inlet port fuel injection (PFI) at low ambient temperatures, the effects of several auxiliary preheating measures, including the intake air preheating, the methanol fuel preheating, the resistance wire, which heats the inlet manifold, and the glow plug, which heats the methanol-air mixture, on the firing behavior of the methanol-fueled engine were studied experimentally by means of a single-cycle methanol injection strategy. The results showed that, with the ambient temperatures below 16°C, the methanol-fueled engine cannot be started reliably without an auxiliary start aid even at a large amount of methanol injected per cycle. Both the intake air preheating and the methanol fuel preheating cannot ensure the reliable firing of the methanol-fueled engine during the cold start, but the resistance wire and the glow plug will do. Under the glow-plug preheating, the amount of methanol injected per cycle for reliable cold start is by 30% less than that of the resistance wire and the maximum combustion pressure in the cylinder is 180% higher. The preheating by the glow plug is better than that by the resistance wire.

骏 李;Changming Gong;Yan Su;Huili Dou;Xunjun Liu

Energy & Fuels

2009-11-19

This study developed a Distributed Combustion Design (DCD) method, based on spatial and temporal distribution of mixture and temperature in cylinder, to optimize the combustion of high-pressure common-rail direct-injection diesel engine. Due to the significant improvements of fuel atomization and evaporation by high-pressure common-rail system, mixing control of fuel and air becomes a critical factor to improve efficiency and emissions. Bowl shape, spray angle, multiple-injection and swirl ratio are effective approaches to control the fuel distribution and movement in cylinder both spatially and temporally, therefore can be used to improve the mixing. The whole space in cylinder was divided into three zones, Chamber, UPcham and Outerclearance. And the start of combustion, the timing of injection impacting on bowl lip, the end of injection and the end of combustion were selected as critical timings for temporal zoning controls. Studies proved that the history of fuel quantity distributed to Chamber was an important parameter affecting mixture and temperature distribution, then thermal efficiency and emissions. Combustion and emissions histories and their relationship with mixture distribution were studied under different approaches and schemes and were validated by single cylinder optical engine tests. Furthermore, the DCD method was put forward. As a result of its application, 2 % reduction of fuel consumption was achieved on a 9 L diesel engine.

骏 李;Kang Li;Haie Chen;Huayu Jin;Fang Hu

2013

The composition and the source of the residue formed in the fuel supply system during operation of the LPG vehicle were investigated by means of the specially designed experiment, the dynamometer bench test, the chemical analysis, and the theoretical study. The results showed that the composition of the LPG fuel residue varies with the variation of the LPG composition, especially its contaminants and their contents. The common residues appear to be phthalates, heavy alkanes (C₁₅-C₃₅), elementary sulfur, copper sulfide, and cuprous sulfide, etc. The analyses revealed that the phthalates come from the rubber additives (e.g. phthalic acid dioctyl phthalate), and their content increases with the solubility parameter of the LPG mixture. The heavy alkanes come from the lub oils in the compressor or pump during refining, transport and storage, not from polymerization of mono-alkenes under the strictly limitation of 1, 3-butadiene. The contents of sulfur and copper sulfide depent upon the sulfur content in the LPG, and strict control of the content of elementary sulfur and hydrogen sulfide may decrease significantly the content of the sulfides in the LPG residue Limited use of copper LPG pipeline may restrain the formation of copper sulfide and cuprous sulfide. By means of careful refining and proper controlling LPG composition, the domestic LPG meet the requirements from the LPG vehicle.

Ying Gao;骏 李;Chang Ji Zhu

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

2007-11