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Duan L.,Jiangsu University | Yuan S.-Q.,Jiangsu University | Hu L.-F.,Wuxi Fuel Injection Equipment Research Institute | Yang W.-M.,National University of Singapore | And 2 more authors.
International Journal of Heat and Mass Transfer | Year: 2016

The present work is to demonstrate the working process and injection performance of a new-type diesel injector, and to make a contrastive analysis of cavitation which potentially occurs near control-valves of the new and another conventional injector. The advanced injector is developed for 250 MPa common rail injection systems of medium or heavy duty commercial vehicles. The originality is the development of a novel control-piston with the outward appearance of a poppet valve. The control-piston can automatically move downwards or upwards owing to pressure changes in related hydraulic chambers, and consequently appropriately activates or deactivates the function of additional inflowing control-orifices to improve system responsiveness. The injection performance demonstration was carried out by one-dimensional (1D) hydraulic mechanical simulation in combination with the experimental data input of actuators. On the other hand the cavitation evaluations, in both the conventional and new structures, were studied numerically by computational fluid dynamics (CFD) based on nonlinear cavitation model and dynamic grid method. Additionally the CFD model was validated against experimental result in terms of mass flow rate of backflow fuel in the conventional structure. The 1D simulation result shows that the new injector is capable of achieving multi-injection and ramp-shaped injection flow rate; closing-delay of injection can be reduced from 1.232 to 0.758 ms, and backflow fuel quantity index can be decreased to 14.1:182.6 which means a reduction of 15.5%. As regards to the contrastive analysis of cavitation, the CFD simulation result of the new structure shows several improvements as follows: a lower velocity field (below 311.88 m/s) near the control-valve, cavitation no longer occurring in the guide-hole, and a reduction of 70.22% in mass exchange rate between vapour-liquid phases near the sealing annulus of valve seat. © 2015 Elsevier Ltd.


Zhang G.,Shanghai JiaoTong University | Qiao X.,Shanghai JiaoTong University | Miao X.,Wuxi Fuel Injection Equipment Research Institute | Hong J.,Wuxi Fuel Injection Equipment Research Institute | Zheng J.,Wuxi Fuel Injection Equipment Research Institute
Fuel | Year: 2012

The fuel injection rate profile and spray characteristics of both the highly dispersed spray nozzle and the conventional nozzle have been studied through experiments. The experimental results indicate that the highly-dispersed nozzle has a higher fuel injection rate, shorter injection duration, shorter spray tip penetration, fatter spray cone angle, smaller spray projected area and larger spray volume than the conventional nozzle. According to the original experimental results and the fluid collision and breakup theories, the SMD of the highly-dispersed nozzle is smaller than that of the conventional nozzle. Additionally, the combustion and emission characteristics of a heavy-duty diesel engine when equipped with the highly-dispersed nozzle and the conventional nozzle respectively have been studied through experiments. The experimental results indicate the tested engine equipped with highly-dispersed nozzles has a lower emission level and better BSFC performance than that equipped with conventional nozzles. All these validate that compared with the conventional nozzle, the highly-dispersed nozzle can shorten the fuel injection duration to save time for the fuelair mixing, promote the fuelair mixing and improve the fuel atomization, which are beneficial to the formation of homogeneous mixture. © 2012 Elsevier Ltd. All rights reserved.


Zhang G.,Shanghai JiaoTong University | Qiao X.,Shanghai JiaoTong University | Miao X.,Wuxi Fuel Injection Equipment Research Institute | Hong J.,Wuxi Fuel Injection Equipment Research Institute | And 2 more authors.
Applied Thermal Engineering | Year: 2012

The work aims not only to exploit the petroleum alternative fuel for relieving the energy crisis, but also to realize the ultra-low emissions of diesel engines fueled with this alternative fuel. The effects of direct coal liquefaction (DCL) on combustion and emissions have been studied in a heavy-duty engine fueled with exhaust gas recirculation (EGR). Two cases of the diesel engine operating condition were studied: 1000 r/min, 110 N m (referred to as Case A) and 1400 r/min, 473 N m (referred to as Case B). The experimental results showed that with the increase of EGR, the maximum in-cylinder pressure, rate of heat release and mean gas temperature decrease; the brake fuel conversion efficiency (BFCE) first increases slightly then decreases; brake specific fuel consumption (BSFC) has the opposite variation trend to BFCE. As the increase of EGR, the nitrogen oxides (NOx) emissions decrease monotonically, the soot emissions increase slightly, the hydrocarbon (HC) and carbon monoxide (CO) emissions increase, and the carbon dioxide (CO 2) and oxygen (O 2) concentration of the exhaust products increases and decreases respectively. The trade-off relationship between NOx and soot emissions can be improved when diesel engines are fueled with DCL instead of diesel. © 2011 Elsevier Ltd. All rights reserved.


Zheng J.-B.,Wuxi Fuel Injection Equipment Research Institute | Miao X.-L.,Wuxi Fuel Injection Equipment Research Institute | Wang X.-Y.,Wuxi Fuel Injection Equipment Research Institute | Hong J.-H.,Wuxi Fuel Injection Equipment Research Institute | Chen X.-Y.,Wuxi Fuel Injection Equipment Research Institute
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2011

On engine test bench, cycle-by-cycle variations of premixed combustion diesel engine in low and medium load conditions were experimentally studied. The effects of EGR, injection timing and injection pressure on the cycle-by-cycle variations were examined. The results show that the engine has shorter combustion duration, quicker heat release and higher pressure rise rate in premixed combustion mode. With EGR rate increasing and injection timing retarding, the maximum combustion pressure and maximum pressure rise rate lower. The cycle-by-cycle variation coefficient of the maximum pressure rise rate increases with the increase of EGR rate and decreases with injection timing retarding. There exists a strong correlation between the early combustion stage and subsequent combustion parameters. At the condition points of smaller cycle-by-cycle variations, the emissions are lower too. The effects of EGR rate, injection timing etc. on the cycle-by-cycle variation coefficients can be expressed well by air fuel ratio. At normal condition the cycle-by-cycle variation coefficient of mean indicated pressure is always below 10%. Some measures to minimize the cycle-by-cycle variations were put forward for less emissions.


Zhu J.-M.,Wuxi Fuel Injection Equipment Research Institute | Peng D.-Y.,Wuxi Fuel Injection Equipment Research Institute
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2011

The current world oil situation and various new-energy concepts were analyzed, and a new-energy development strategy for China was put forward. At present stage China must continue utilizing conventional energy more rationally and efficiently, meantime explore emphatically practical and effective new-energy resources, particularly realize their industrialization. If China launches development of new energy rashly and disorderly, neglecting the conventional energy technology improvements, it may fall into a bottomless pit of money and efforts, and waste the accumulated achievements in automobile and internal combustion engine industries for many years, thus being behind the developed countries once more.


Lu L.-Y.,Wuxi Fuel Injection Equipment Research Institute | Wang J.-H.,Wuxi Fuel Injection Equipment Research Institute | Fan R.,Wuxi Fuel Injection Equipment Research Institute | Ju Y.-S.,Wuxi Fuel Injection Equipment Research Institute | Zhang Y.-M.,Wuxi Fuel Injection Equipment Research Institute
Lecture Notes in Electrical Engineering | Year: 2015

The effects of the position relationship between work air gap and coil, the coil wire diameter, and the coil turns on the electromagnetic characteristics are analyzed by using the software Ansoft Maxwell. The coil parameters are determined by optimizing the coil design. © Springer-Verlag Berlin Heidelberg 2015.


Yin B.,Jiangsu University | Yu S.,Jiangsu University | Jia H.,Jiangsu University | Yu J.,Wuxi Fuel Injection Equipment Research Institute
International Journal of Heat and Fluid Flow | Year: 2016

A special spray model is applied to study the spray behavior with high injection pressure and micro-hole nozzle. To reveal the cavitation in diesel nozzle and its influence on spray and atomization, the Large Eddy Simulation (LES) turbulence model is adopted to detect the cavitation, and then the special spray model coupling the cavitation is build. From research results, three important conclusions can be drawn. Firstly, the cavitation flow can raise the effective velocity at the nozzle exit and such effect become even more obvious with higher injection pressure, e.g.180. MPa. Secondly, the applied spray model is in good agreement with the spray characteristics and images obtained from the EFS8400 spray test platform. Thirdly, the cavitation with high injection pressure and micro-hole nozzle can increase the spray cone angle and reduce the spray penetration; the cavitation intensity has a great impact on the spray velocity field and vorticity intensity, especially at the initial spray field under the condition of high injection pressure. © 2016 Elsevier Inc.


Yao C.,Tianjin University | Geng P.,Tianjin University | Yin Z.,Tianjin University | Hu J.,Tianjin University | And 2 more authors.
Fuel | Year: 2016

Diesel engine performance and emissions are closely related to fuel atomization and spray processes, which in turn are strongly influenced by nozzle geometry. In this study, five kinds of single-hole cylindrical injectors which have different orifice diameters (0.13-0.23 mm) and lengths (0.7-1.0 mm) were employed to research the effects of the nozzle geometry on spray droplet size distribution and corresponding combustion characteristics. The spray droplet size spatial distribution was measured with the Phase Doppler Particle Analyzer (PDPA). The results show that the Sauter Mean Diameter (SMD) reduces with the increase of the distance from injector tip and the SMD of the central axis is bigger than that of the periphery. With the increase of the injection pressure (40-120 MPa), the spray SMD decreases significantly. In addition, as the orifice diameter goes smaller, the SMD decreases and the effect of the orifice diameter on the spray SMD becomes weak. Meanwhile, as the orifice length goes longer, the SMD decreases when the orifice diameter is 0.13 mm. And then, the combustion characteristics were experimentally investigated in a constant volume chamber with optical access. Time-resolved images of the natural luminosities (indicator of soot) from the combustion process were captured by high speed camera and combustion pressure was also acquired. It is found that there is a good corresponding relationship between spray SMD, combustion heat release rate and flame luminosity. That is to say, the way to decrease SMD reduces greatly the natural luminosities and improves combustion heat release rate. This article presents the effects of nozzle geometry on droplet size distribution and combustion, and provides important references for injector manufacture. © 2016 Elsevier Ltd. All rights reserved.


Li P.,Beijing Institute of Technology | Zhang Y.,Beijing Institute of Technology | Xie L.,Beijing Institute of Technology | Hu L.,Wuxi Fuel Injection Equipment Research Institute
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2014

Oil pressure fluctuation caused by last injection can lead to oil mass deviation of this injection during multi-injection of high pressure common-rail system. Influence of rail pressure on the oil mass deviation amplitude of the second injection under two different injection pulse width of the first injection is researched. The results show that the changing of oil mass deviation amplitude with rail pressure shows different law under different injection pulse width of the first injection. The influence of rail pressure on the amplitude of pressure fluctuation caused by a single injection is also studied under two different injection pulse width. The results show that the influences of rail pressure on the oil mass deviation amplitude and pressure fluctuation amplitude are almost the same when the injection pulse width is small, but there is a difference when the injection pulse width is large. Mechanism of the influences of rail pressure on oil mass deviation amplitude is discussed in detail. A coefficient named injection time deviation coefficient which demonstrates the mechanism of the influence of rail pressure on oil mass deviation is put forward. The influence law of rail pressure on oil mass deviation amplitude is acquired. © 2014 Journal of Mechanical Engineering.


Fei D.,Wuxi Fuel Injection Equipment Research Institute | Zeng W.,Wuxi Fuel Injection Equipment Research Institute | Shi H.,Wuxi Fuel Injection Equipment Research Institute | Zhou L.,Wuxi Fuel Injection Equipment Research Institute
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

The DoE (Design of Experiments)-based calibration method that incorporates models is called MBC (Model Based Calibration) and accomplishes modeling and optimization with MATALAB Toolbox- MBC Model Fitting and MBC Optimization. This methodology is provided with less calibration time as well as identical accuracy of measurement. This paper presents a DoE-based experiment to investigate the effects of the injection timing, rail pressure, pilot injection timing and pilot injection quantity on performance and emissions of a common rail heavy duty diesel, find out the optimal combination of such parameters. © 2014 IEEE.

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