Effect of Hho Addition on Combustion and Emission in Si Engine with Butanol Direct Injection and Gasoline Port Injection

Abstract

As a renewable biofuel fuel , butanol can not only reduce the consumption of fossil energy, but also effectively improve the performance of engine. HHO is introduced into the engine cylinder by means of inlet negative pressure suction to further optimize the performance of the engine with butanol direct injection  and gasoline port injection . The results show that under all test conditions, with the increase of HHO flux, IMEP, Pmax and NO increase, CA 0-10, CA 10-90, CO and HC decrease.  It is worth noting that this improvement is more obvious when BDIr > 40%. HHO can effectively offset the negative impact of large proportion of butanol vaporization latent heat and improve the engine's tolerance to BDIr. Moreover, the engine performance gap between different DIT is also shortened with the addition of HHO, which reduces the engine's sensitivity to DIT. In addition, it can also be found that butanol can improve the surge of NO  caused by HHO.  In general, biofuel butanol and clean fuel HHO can work together well and "16L / min HHO + 40% BDIr + 60% GPIr + 300 ° CA BTDC DIT" is the optimal combination of the BDI + GPI + HHO engine.

Keywords: SI engine, HHO, Butanol, Combustion, Emission