Experimental Study on Effect of Hot EGR on Combustion Characteristic of HICE under high load conditions

摘要

In order to study the effect of hot EGR on combustion characteristic of hydrogen internal combustion engine (HICE), experimental study was taken on a 4 cylinder, 2.0L HICE. The speed was 3000 rpm, and the throttle was fully open, the load was adjusted through quality regulation. When the hydrogen flow ratio was 2.79 kg/h, the ignition advanced angle was optimized as maximum brake torque (MBT) timing, then the EGR valve was opened, and EGR valve was adjusted to control the flow of exhaust gas that back into the intake manifold. The test results show that: as the EGR ratio changing from 0 (the EGR valve is fully closed) to 43.8% (the EGR valve is fully opened), the in-cylinder pressure is decreasing with the EGR ratio increasing; the coefficient of variation in indicated mean effective pressure (COV_(imep)) is not changing significantly at high load conditions, changing range is less than 1%; CA50 is postponed from 11.8°CA to 15.2°CA with EGR ratio increasing.