Experimental investigation of port injection of acetylene in DI diesel engine in dual fuel mode

As the world finds itself in the midst of universal energy shortage, compounded by a parallel need to reduce pollutants of all kinds; we must take serious look at novel sources of abundant energy and methodology of its use. Acetylene with its remarkable combustion properties appear to be proving itself as the best fuel for future internal engines if it is utilised properly. Because of inherent difficulties in handling acetylene, technology has emphasized the utilization of acetylene by injection techniques to combat back fire in internal combustion engines. An experimental investigation was carried out on a single cylinder, air cooled, DI diesel engine designed to develop 4.4 kW at 1500 rpm. Acetylene was injected into the intake port as a secondary fuel and diesel was injected directly into the cylinder. The optimized injection time of 5 degrees aTDC and injection duration of 90 degrees CA (9.9 ms) was arrived. The gas flow rate was fixed at 110 g/h, 180 g/h and 240 g/h. The combustion, performance and emission parameters were studied for the above flow rates by varying the load from low load to full load. Results show that NO(x), HC and CO emissions reduced when compared to diesel operation due to leaner operation. A marginal increase in smoke emission was observed and brake thermal efficiency was nearer to diesel operation. On the whole it is concluded that without loss in thermal efficiency, safe operation of acetylene is possible in timed port injection technique. Reduced NO(x), HC and CO emission levels, with marginal increase in smoke emission level were achieved. (C) 2011 Elsevier Ltd. All rights reserved.