| Abstract | An 8.2 L Detrolt Diesel engine was modified for single cylinder Otto cycle operation and tested at various compression ratios using ammonia fuel. At 1800 rpm, a best net indicated thermal efficiency of 47.5% as achieved with an 18:1 compresslon ratio. This performance was achieved using a vapour carburetor, high energy ignition system and high combustion chamber turbulence to promote rapid combustion. No secondary fuel addition or combustlon enhancers in the fuel were required over the tested speed range of 1000 to 3000 rpm for smooth and efficient engine operation. This engine, which was naturally aspirated, achieved a power output with ammonia fuel equal to that achieved with a turbocharged engine using diesel fuel. Tests conducted using hydrogen addition did not provide increased power output, however a slightly higher thermal efficiency of 49.5% was achieved. Engine performance data for each compression ratio and exhaust emissions and pressure volume data for the 18:1 compression ratio are presented. Catalytic treatment of the exhaust gases reduced the unburned ammonia emissions to less than 50 ppm, but increased the nitric oxide emissions under some conditions. The air/fuel ratio had a large effect on nitric oxide emissions. |
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