乙醇/柴油发动机醇醛排放的测试技术研究

为了测量乙醇/柴油发动机新的排放物——乙醇和乙醛,对气相色谱分析测试技术进行了研究。通过对不同采样方法和采样条件的比较分析,确定了以去离子水作为吸收液的冰水浴两级吸收采样方法,实现了对发动机尾气中乙醇和乙醛的采样,吸收效率大于96%;通过引入采样系统稀释系数、流量校正系数和吸收效率修正系数的理论计算,提高了测量的准确度;建立了一套完整的色谱分析方法和色谱标定方法,利用气相色谱仪实现了对样品中乙醇和乙醛的分离定量测试;整个测量系统对排气中的乙醇和乙醛检测限值为0.1×10-6,最大极限误差为0.5×10-6,并在一台实际乙醇/柴油发动机上进行了应用。

Research on Test Technology for Ethanol and Acetaldehyde Emissions from Ethanol-diesel Blend Engine

Research on gas chromatography(GC) technology was carried out for measuring new emissions like ethanol and acetaldehyde in the exhaust of ethanol-diesel Blend engine.A two-stage ice water bathed sampling system which used the deionized water as the absorption liquid was built through comparison and analysis among different sampling methods and conditions,the system realized the absorption of the ethanol and acetaldehyde in the engine exhaust,and its absorption efficiency was beyond 96%.The theoretical calculation of dilution coefficient,sampling volume corrected coefficient and absorbing efficiency corrected coefficient in the system ensured the high measurement accuracy.A complete GC analysis and calibration method was established to separate and measure ethanol and acetaldehyde quantitatively in engine exhaust.The limit of measuring ethanol and acetaldehyde in the exhaust for the system was 0.1×10-6,the maximum error was 0.5×10-6 Finally the system was applied successfully to the emission testing of an actual ethanol-diesel Blend engine.