INFLUENCE OF INLET WATER INJECTION ON ENERGY
CONSERVATION AND EMISSION OF GASOLINE ENGINE |
Jiangtao Xu , Zhiyuan Zhou , Liyi Jiang , Haojie Zhou , Chuan Zhang |
School of Mechanical Engineering, Nanjing Institute of Technology |
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ABSTRACT |
Increased compression ratio of auto engine can effectively improve thermal efficiency. However, the risk of
engine knock becomes higher when increasing the intake boosting. In this paper, the role of an inlet Water Injection (WI)
system in improving the performance of a spark ignition engine was investigated, which was through a comparative study of
Miller cycle with electromagnetic intake valve train (EMIT). The numerical simulation method was developed in AVL
BOOST based on the engine test rig, and then the port water injection modelling was introduced. The results showed that
when the engine speed was lower than 1800 r/min, the water spray scheme had a better effect on the engine performance as
compared with the Miller cycle, and such advantage was increasingly significant with the decrease of the speed. This is due to
the fact that the water injection takes into account the temperature reduction in the cylinder. When the engine speed was over
1800 r/min, it had a negative impact on engine performance with IWI due to the excessive suppression of combustion. This
study provides a theoretical basis for design and research of gasoline engines |
Key Words:
Compression ratio, Water injection (WI), Knocking, Miller cycle, Emission performance |
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