Effect of Excess Air Ratio on Idle Performance of a HCNG (H₂+CNG) Engine with Different Hydrogen Blend Ratios

Abstract:

To investigate the idle performance of a HCNG with high hydrogen blend ratios, the effects of different excess air ratios (λ) and different hydrogen blend ratios on combustion, indicated thermal efficiency (ITE) and emissions of a 6-cylinder CNG engine were investigated. The results show that, with the increase of hydrogen blend ratio, rather high ITE can be achieved in a much wider range of λ. Under conditions of λ=1.2~1.4, emissions of CH₄, NMHC and CO are relatively low for different hydrogen blend ratios. When the hydrogen blend ratio is greater than 75%, emissions of CH₄, HMHC and CO increase only slightly with the increase of λ. NO_x emissions increase with the increase of hydrogen blend ratio. And these emissions reach their peaks for different hydrogen blend ratios under the conditions of λ=1.1-1.2.

• Periodical: Advanced Materials Research (Volumes 724-725)
• Pages: 1336-1339
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.724-725.1336
• Online since: August 2013
• Authors: Yi Tuan He, Hai Jiang Qiao
• Keywords: Excess Air Ratio, Exhaust Emission, HCNG, Idle, Indicated Thermal Efficiency

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