不同大气压力下E15含水乙醇/柴油对柴油机性能与排放的影响

为了探索掺烧乙醇后大气压力对柴油机性能和排放的影响和变动规律,在增压柴油机上进行了不同大气压力下燃用纯柴油和掺烧15%含水乙醇的对比试验研究。试验结果表明:随着大气压力的上升,动力性略有提高;气压从81kPa上升至90kPa时,燃油消耗率be的改善幅度较大,从90kPa上升至100kPa时,be的改善幅度较小,大气压力上升对低负荷区域的be变化影响较小,对中、高负荷区域的be有明显改善;气压在81kPa时,中、低负荷工况的HC和CO明显上升,随着气压的上升,HC和CO得到明显改善,高负荷工况时的HC和CO分别趋于原机水平或低于原机水平;气压变化对NOx排放的影响较小,但均比原机有所下降;气压低于90kPa时碳烟排放均比原机明显下降,大于90kPa后对碳烟排放的改善效果减弱。

Effect of Atmospheric Pressure on Performance and Emissions of Diesel Engine Fueled with E15 Hydrous Ethanol/Diesel Blend

In order to clear effect of atmospheric pressure on performance and emissions of the diesel engine fueled with diesel oil mixed by 15% hydrous ethanol,comparative tests on bench were conducted in a turbocharged diesel engine fueled separately with pure diesel oil and E15 hydrous diesel/ethanol blend under different atmospheric pressures.Results indicate that with the atm.pressure rising,engine power is slightly increased;the brake specific fuel consumption be gets great improvement with the atm.pressure rising from 81 kPa to 90 kPa,while with it rising from 90 kPa to 100 kPa,the improvement lowers;and the atm.pressure rising has little influence on be in low load condition but has remarkable influence in middle and high load conditions.At 81 kPa atm.pressure,HC and CO emissions go up significantly in low and middle load conditions,but with atm.pressure rising it gets remarkable improvement,meanwhile in high load conditions the HC and CO emissions trend to diesel engine level or worse.The atm.pressure has little influence on NOx emissions,but NOx emissions have a slight drop at all load conditions.When the atm.pressure declines below 90 kPa,the smoke has a remarkable drop compared to that of diesel engine.When the atm.pressure is over 90 kPa,the improving effect weakens.