科创中国

The friction loss of a First Automobile Works (FAW) produced engine was reduced by a method, which combines tribology structural optimization design and the Diamond-Like Carbon (DLC) film. Based on the friction strip-down test and the performance test, the effects of main parameters of the crank-connecting rod mechanism and valve train on engine friction loss were investigated. The influence of engine friction loss on the fuel consumption was also investigated. The test results show that tribology structural optimization design and the DLC film can effectively decrease the mechanical friction loss of the engine. The average mechanical friction loss of engine at different speeds is decreased by 17.1%, and the average fuel consumption is decreased 2.5%.

Bin Wu;骏 李;Kang Li;Fu Jian Hou;Wen Hu Jiang

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

2014-1

Different from traditional engine test, an optical constant volume chamber simulated HTHP ambient condition was employed by using biodiesel-diesel-butanol blends. With high-speed camera and synchronized copper vapor laser, recorded fuel spray and combustion process, measured liquid jet penetration length and heat release rate under variable ambient temperature and fuel composition conditions. With ambient temperature increasing, burn process converted from premixed combustion to diffusion combustion, and the micro-explosion became weak and disappeared. It was concluded that micro-explosion could occur under particular initial ambient temperature and specific blend ratio conditions for the biodiesel-diesel-butanol fuel, that will distinctly enhance fuel evaporation and premixed combustion process.

Yu Liu;骏 李

2011

Based on GT-Power software, the simulation model of an Argon cycle engine(Argon engine) which uses Argon as working medium in place of Air(N₂) is presented. The model was calibrated using the experimental data from a GDI engine. The result shows that the model was proved to be feasible for simulation. This paper discusses the effect of Argon gas volume percentage, compression ratio, ignition timing and impurities of mixtures on Argon engine performance and gives several methods to recover the engine output power and torque.

Yinchun Gong;Jun Deng;D. O.U. Huilin;Yanfeng Gong;骏 李;Robert W. Dibble;Yibo Shen;理光 李

2015

An experimental study on blended combustion for dimethyl ether (DME) with diesel was carried out for a 4-cylinder diesel engine. DME was premixed with air through a mixer and then was entered the cylinder. Diesel was supplied by original fuel system. The experimental results show that the auto-ignition is advanced with more DME and the pre-ignition is obvious, which leads to the engine operation roughness and combustion deterioration. When the ignition inhibitor (LPG) added into DME is exceeded 30%, it can retard the auto-ignition and control the start of combustion effectively.

Changji Zhu;骏 李;Ying Gao;Tao Yang

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

2008-9

The ammonia content, decomposition temperature and decomposition rate of ammonium bicarbonate, ammonium carbonate and ammonium carbamate are investigated by theoretical analysis, Thermogravimetric Analysis (TGA) experiment and equilibrium pressure experiments. Results show that ammonium carbamate has the highest ammonia content, followed by ammonium carbonate, and ammonium bicarbonate has the lowest ammonia content. Ammonium carbonate and ammonium carbamate can decompose from room temperature, but when heated to 100 ℃ ammonium bicarbonate only decomposes 5.6%. When the temperature is below 90 ℃, the decomposition rate of ammonium carbamate is higher than that of ammonium carbonate. Under the same period and same temperature, ammonium carbamate produces more ammonia. The decomposition equilibrium pressures of ammonium carbonate and ammonium carbamate are similar; both are excellent candidates of reductant of Selective Catalytic Reduction (SCR) system, but ammonium carbamate has more obvious advantages.

Jun Yan Ma;Da Wei Qu;骏 李

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

2015-11-1

The paper has modeled and simulated the combustion process of big bore CNG engine by three-dimensional simulation software AVL FRIE. Based on test validation in the model, the effect on position of the dual spark plug for cylinder initial flame kernel development and flame propagation process was researched. The results showed that: When A=0.5, the flame propagation distance shortened by half, a certain intensity of turbulence formed when the compression stroke ended, the combustion speed was the fastest, the combustion duration was the shortest. If dual spark plug spacing is too small, the two flames meet prematurely will cause interfere with each other, and reduce the combustion speed of the overlapping region of the flame surface, increase the heat losses. Otherwise,if the distance is too large, close to the combustion chamber wall, the combustion space is narrow, the flame propagation space is restricted, then flame development is slow.

Chang Qing Song;骏 李;Da Wei Qu;Kai Yu

2013

NOx emission of diesel engine is an important pollutant to the environment, in the bench test of SCR technology for the diesel engine NOx reducing effect. Diesel engine NOx to ESC test cycle emission by 10.73 g kw× h,down to 3.24 g kw× h; ETC test cycle of the diesel engine NOx emission decreased from 9.533 g kw× h to 2.98 g kw× h, the diesel engine emissions to meet Euro IV emission standards. Experimental results showed that SCR can effectively reduce NOx emission of diesel engine and the pollution of the environment.

Jun Yan Ma;Da Wei Qu;骏 李

2014

The effects of ambient temperature, amount of liquefied petroleum gas (LPG) injected per cycle, injection timing of LPG, ignition timing and the electric battery voltage on firing performance, and hydrocarbon (HC) emissions from the first cycle of an electronically controlled inlet port LPG injection spark-ignition (SI) engine were investigated during cold start by means of a cycle-by-cycle control strategy. The results indicated that the amount of LPG injected per cycle is the key factor to ensure the first firing cycle of the LPG engine during cold start; a proper amount of injected LPG makes a reliable start of the LPG engine. The effect of ambient temperature on the minimum amount of injected LPG required for firing is relatively small. If the amount of injected LPG and injection timing of LPG are controlled reasonably to ensure all of the fuel-air mixture to enter the cylinder on time, it is possible to realize the ideal firing in the same cycle with LPG injection during engine cold start. Optimal control of injection timing of LPG and ignition timing improves firing performance and reduces HC emissions during cold start. Increasing the electric battery voltage raises the maximum instantaneous cranking speed and reduces HC emissions from the LPG engine during cold start.

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

Energy & Fuels

2009-9-17

In this study, the spray characteristics and evaporating processes of DME fuel were investigated using the SCHLIEREN optical system and single-hole injectors in a constant volume chamber at room temperature. The photographs taken at different chamber pressures, injection pressures, orifice diameters and injection quantities were compared and analyzed. The results show that DME spray has a slower penetrating speed, wider spray angle, and much quicker evaporating processes than the diesel spray.

骏 李;Yoshio Sato;Akira Noda

SAE Technical Papers

2001

The study is based on FJ-600 pilot injection measuring system. It is found that the injection quantities increase with the fuel injection pressure's decrease or the back pressure's increase in some working conditions, which would affect the fuel supply accuracy and engine performances. This is because the needle movements are affected by the fuel pressure and back pressure directly, the injector's effective flow section and real injection duration change obviously. Increasing the spring stiffness and electromagnetic force will be of benefits to improving the injector's injection characteristic.

骏 李;理光 李;Hua Chun Jiang

Shanghai Jiaotong Daxue Xuebao/Journal of Shanghai Jiaotong University

2004-7