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Hydraulic variable valve system for improving the performance of internal combustion engine

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Category: Mining mechanics

Last Updated on Saturday, 02 April 2016 21:20

Published on Saturday, 02 April 2016 21:20

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Authors:

Yuliang Xu, Guizhou University, Guiyang, Guizhou, China

Ziqin Wang, Guizhou University, Guiyang, Guizhou, China

Jiadui Chen, Guizhou University, Guiyang, Guizhou, China

Abstract:

Purpose. The engines with variable valve system can achieve better performance for all engine speed compared to those with fixed valve timing and lift. In this article, a hydraulic variable valve system is proposed according to the requirements of the engine. Both intake and exhaust valves can all be regulated.

Methodology. We have built a valve movement testplatformand tested the hydraulic variable valve system performance for valve regulation. Using theintake and exhaust valve curves regulated by hydraulic variable valve system, we have predicted the performance of engineby 1D simulation software AVL Boost.

Findings. The test results show that the valve timing and lift can be continuously varied according to the engine speed by hydraulic variable valve system. The simulation results show that the engine with various valve timing and lift has a certain improvement of volumetric efficiency, brake power, brake torque, brake specific fuel consumption and residual gas coefficient compared to base engine at different engine speed. The improvement is obvious especially in low and middle speed.

Originality. The construction and workingprinciple of hydraulic variable valve system is new, and the regulation strategy of valve is different from others.

Practical value. Thehydraulic variable valve system can be applied on engines for better performance and has advantages of simple structure, easy control and low cost.

References:

1. Liu Fushui,Shang Yong,Wang Li, et al.(2013), "Influence of Intake Closing Timing on Gas Exchange Process in Internal Combustion Engine", Chinese Internal Combusion Engine Engineering, vol.34, no.6, pp.51−57.

2. Shang Yong, Liu Fushui, Lu Ying (2015), "Influence of Valve Overlap on Air Exchange Process in Internal Combustion Engine", Chinese Internal Combustion Engine Engineering, vol.36, no.4, pp.104−111.

3. Shang Yong, Liu Fushui, Wang Yali (2015), "Influence of Exhaust Valve Opening Timing on Gas Exchange Process in Internal Combustion engine", Chinese Internal Combustion Engine Engineering, vol. 34, no. 2, pp.7−12.

4. Verhelst, S., Demuynck, J.,Sierens, R., Huyskens, P. (2010), "Impact of variable valve timing on power, emissions and backfire of a bi-fuel hydrogen/gasoline engine", International Journal of Hydrogen Energy, vol. 35, no. 9, pp. 4399−4408.

5. Hu Zhilong, Gui Yong, Min Xu, et al. (2015), "Design of a variable valve hydraulic lift system for diesel engine", Journal of Mechanical Science and Technology, vol. 29, no. 4, pp. 1799−1807.

6. Tomoda, T., Ogawa,T., Ohki, H., et al. (2010), "Improvement of diesel engine performance by variable valve train system", International Journal of Engine Research, vol. 11, no. 5, pp. 331−44.

7. Okazaki, A. (2011), "Development of highly efficient engine with Electromagnetic variable valve lift", Nippon Institute of Technology, vol. 41, no. 2, pp. 9−10.

8. Haas, Michael. (2010), " Electro-hydraulic fully variable valve train system", AutoTechnology,vol. 10, no. 2, pp. 38− 43.

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