Experimental investigation of hydroxy gas enriched natural gas as an alternative fuel (HHO-CNG) in pilot injection diesel engines

Increasingly restrictive emissions norms and renewed focus on energy efficiency drive the current search for alternative fuels and combustion strategies for IC engines. Using natural gas and hydrogen blends that can absorb their owns negative effect on combustion and emission parameters when mixed each other can be a very good alternative due to the attractive fuel properties regarding emission reduction and engine operation. Alternative gaseous fuels can be easily used on SI engines without any modification. However, in CI engine, two optional ways were answered the problem when gas fuels usage. First one is converted diesel engine to SI working structure and it needs modification which is expensive and does not allow diesel operation again. But, second method is, that used in this thesis, dual-fuel mode operation which can be handled with pilot diesel ignition phenomenon. The aim of the thesis is to investigate the effects of a non-modified pilot diesel ignition CI engine's performance and emissions under operated with HHO-CNG fuel mixtures experimentally. A brief introduction and critical literature review presented. Experimental set-up, mixtures ratios of HHO-CNG, substitution of diesel fuel process and devices explained and performed briefly. The effects of 20, 25, 30 % (vol/vol) HHO-CNG operation was explored. A comparison of HCNG and HHO-CNG fuel mixtures affects on engine performance and emission parameters also determined. Additionally a cost analysis was performed and explained. As a result, this study exhibits the availability of usage HHO-CNG fuel mixtures in a non-modified diesel engine via pilot diesel ignition resulted improving the engine performance and reducing the exhaust emissions.