Loss analysis of electromagnetic valve train under different service conditions

Author(s):  
Xinyu Fan ◽  
Jie Yin ◽  
Shichuan Su ◽  
Hongyan Pang ◽  
Yindong Song

Electromagnetic valve train (EMVT) can realize independent, real-time and continuous valve motion regulation through the precise motion servo control, which has great potential to improve the efficiency of internal combustion engines. As an electromechanical integration device, EMVT is driven by electric energy, and the loss distribution is complex and changeable under different service conditions. Especially when the EMVT is used in exhaust system, the high gas pressure after combustion will increase the energy loss and operating temperature significantly. In order to improve the device performance, this study analyses the loss distribution and variation law of EMVT under different service conditions. First, the flux density is obtained by the 3D finite element simulation. In combination with the valve train dynamic Matlab/Simulink model, the copper loss and iron loss of EMVT under typical conditions are explored in detail. Then, the influence of the motion parameters (transition time) and condition parameters (gas pressure) on EMVT’s loss are calculated and analyzed significantly. In the end, the accuracy of the loss models and analysis results is verified by the experiment based on linear load simulator.

2019 ◽  
Vol 146 ◽  
pp. 768-774 ◽  
Author(s):  
Xinyu Fan ◽  
Siqin Chang ◽  
Jiayu Lu ◽  
Liang Liu ◽  
Shouguang Yao ◽  
...  

2016 ◽  
Vol 17 (3) ◽  
pp. 361-367 ◽  
Author(s):  
X. Y. Fan ◽  
L. Liu ◽  
S. Q. Chang ◽  
J. T. Xu ◽  
J. G. Dai

2021 ◽  
pp. 146808742098626
Author(s):  
Pooyan Kheirkhah ◽  
Patrick Kirchen ◽  
Steven Rogak

Exhaust-stream particulate matter (PM) emission from combustion sources such as internal combustion engines are typically characterized with modest temporal resolutions; however, in-cylinder investigations have demonstrated significant variability and the importance of individual cycles in transient PM emissions. Here, using a Fast Exhaust Nephelometer (FEN), a methodology is developed for measuring the cycle-specific PM concentration at the exhaust port of a single-cylinder research engine. The measured FEN light-scattering is converted to cycle-resolved soot mass concentration ([Formula: see text]), and used to characterize the variability of engine-out soot emission. To validate this method, exhaust-port FEN measurements are compared with diluted gravimetric PM mass and scanning mobility particle sizer (SMPS) measurements, resulting in close agreements with an overall root-mean-square deviation of better than 30%. It is noted that when PM is sampled downstream in the exhaust system, the particles are larger by 50–70 nm due to coagulation. The response time of the FEN was characterized using a “skip-firing” scheme, by enabling and disabling the fuel injection during otherwise steady-state operation. The average response time due to sample transfer and mixing times is 55 ms, well below the engine cycle period (100 ms) for the considered engine speeds, thus suitable for single-cycle measurements carried out in this work. Utilizing the fast-response capability of the FEN, it is observed that cycle-specific gross indicated mean effective pressure (GIMEP) and [Formula: see text] are negatively correlated ([Formula: see text]: 0.2–0.7), implying that cycles with lower GIMEP emit more soot. The physical causes of this association deserve further investigation, but are expected to be caused by local fuel-air mixing effects. The averaged exhaust-port [Formula: see text] is similar to the diluted gravimetric measurements, but the cycle-to-cycle variations can only be detected with the FEN. The methodology developed here will be used in future investigations to characterize PM emissions during transient engine operation, and to enable exhaust-stream PM measurements for optical engine experiments.


2018 ◽  
Vol 129 ◽  
pp. 833-840 ◽  
Author(s):  
Maoyang Hu ◽  
Siqin Chang ◽  
Liang Liu ◽  
Yaxuan Xu ◽  
Jiangtao Xu

2004 ◽  
Author(s):  
Christoph Hartwig ◽  
Olaf Josef ◽  
Klaus Gebauer

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Mohamed Kamal Ahmed Ali ◽  
Hou Xianjun

AbstractThe friction between two sliding surfaces is probably one of the oldest problems in mechanics. Frictional losses in any I.C. engine vary between 17% and 19% of the total indicated horse power. The performance of internal combustion engines in terms of frictional power loss, fuel consumption, oil consumption, and harmful exhaust emissions is closely related to the friction force and wear between moving parts of the engine such as piston assembly, valve train, and bearings. To solve this problem, most modern research in the area of Nanotribology (Nanolubricants) aims to improve surface properties, reduce frictional power losses, increase engine efficiency, and reduce consumed fuel and cost of maintenance. Nanolubricants contain different nanoparticles such as Cu, CuO, TiO


2021 ◽  
pp. 41-47
Author(s):  
Vladimir Tupov ◽  
O. Matasova

Insertion losses as the main characteristic that mathematically describes the acoustic efficiency of a noise silencer has been considered. This characteristic shows the reduction of noise generated by its source, in particular by the internal combustion engine’s exhaust system, at the control point as a silencer use result. Has been presented a mathematical description of the insertion losses, and have been considered parameters necessary for calculating this characteristic. Has been demonstrated the analytical dependence of impedance for the sound emission by the exhaust system’s end hole from the coefficient of acoustic waves reflection by this hole. The performed analysis of the widely used formulas for calculating the coefficient of sound reflection by the end hole has showed their insufficient accuracy for project designs performing. Have been proposed calculation dependences providing high accuracy for calculations of the reflection coefficient modulus, and the attached length of the channel end hole without a flange in the entire range of the existence of plane waves in it. It has been shown that the end correction of this hole at ka = 0 is 0.6127, and not 0.6133, as it was mistakenly believed until now in world acoustics. Has been proposed a method for calculation the exhaust noise source internal impedance. This method more accurately, in comparison with the already known ones, describes the acoustic processes in the internal combustion engine’s exhaust manifold, thanks to increases the accuracy of calculation the silencer acoustic efficiency, that allows develop the silencer at the early stages of the design of an automotive internal combustion engine.


2018 ◽  
Vol 202 ◽  
pp. 02003
Author(s):  
Maoyang Hu ◽  
Siqin Chang

Cylinder deactivation (CDA) is a fuel consumption reduction technology for gasoline engines. Skip fire is a new type of CDA because the load and the density of firing cylinder are in proportion to the torque demand. However, it is difficult to realize because valves need to be switched between valve deactivation and normal operation stroke by stroke. The Electromagnetic valve train (EMVT) provides a fully flexible control method to achieve skip fire. In the paper, a new skip fire strategy based on electromagnetic intake valve train (EMIV) is proposed. Then, the oxygen concentration of the exhaust pipe, energy losses, in-cylinder pressure of the skipped cycle and exhaust gas recirculation (EGR) rate of the firing cycle are studied by the 1D simulation in GT-Power. The results shows the majority of gas sucked into the skipped cylinder is exhaust gas by reasonable control of IVO and IVC, and the exhaust oxygen-rich can be avoided. Meanwhile, EGR rate of the firing cylinder and energy losses of the skipped cylinder are maintained at lower level. At the conditions of 1200 and 1600 rpm, fuel economy has been improved respectively 8.1%-16.6% and 6.4%-14.6% when the brake mean effective pressure (BMEP) ranges from 0.4MPa to 0.2MPa.


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