Analysis and Optimization of Two-Stroke Compression Release Engine Brake Performance
Based on a 14.8 L six-cylinder supercharged diesel engine,the braking performances of CRB1.5 and CRB2.0 two-stroke brake valve profiles were analyzed,and it was found that the braking power was maximum when CRB2.0 valve profiles were used without brake gas recirculation(BGR)phase.Based on DoE method,the CRB1.5 and CRB2.0 valve profiles were op-timized respectively.The results show that there is an optimal valve profile at different engine speeds to be able to maximize the braking power,and the optimized CRB1.5 valve profile has greater braking power at high speed.At 1 600 r/min,1 800 r/min and 2 100 r/min,the braking power reaches 378 kW,476 kW and 581 kW respectively,and the optimization rates were 48.9%,61.0%and 65.3%respectively.After the optimization of CRB2.0 valve profile,the braking power reaches 402 kW,469 kW and 528 kW respectively at the three speeds,and the optimization rates were 34.7%,30.6%and 23.2%respectively.