Research Into Emissions of Nitrogen Oxides When Converting the Diesel Engines to Alternative Fuels

We conducted theoretical and experimental research into emissions of nitrogen oxides in exhaust gases of the diesel engines, re-equipped for gas.The research is important because the emissions of nitrogen oxides in the exhaust gases are one of the biggest environmental problems at the present stage of development of designs for internal combustion engines. Therefore, reducing the emissions of nitrogen oxides in diesel engines by re-equipping them to gas fuel is an important task for specialists in design and operation of internal combustion engines.The result of theoretical research is the mathematical model that we constructed in order to calculate emissions of nitrogen oxides in the exhaust gases of diesel engines and the engines, converted to gas fuel. Based on experimental research, we have established dependences of emissions of nitrogen oxides in exhaust gases of the diesel engines, re-equipped for gas, on loading and the crankshaft rotation frequency. Studies have shown that diesel engines, which are converted to alternative gas fuel, reduce emissions of nitrogen oxides in the exhaust gases in a range from 13.9 % to 47.1 % depending on engine rotation and load. The results obtained make it possible to reduce the emissions of harmful substances in exhaust gases of automobile engines and optimize design of the systems for exhaust gases recirculatio

Fuel Economy Raising of Alternative Fuel Converted Diesel Engines

As a result of the theoretical research, calculations of the theoretical indicated specific fuel consumption for different methods of conversion of diesel engines to gas were carried out. The traditional method of derating in the conversion of diesel engines to gas by installing additional gaskets between the cylinder head and block was considered and the method of derating due to late intake valve closing was proposed.As a result of in vitro experimental research with different methods of conversion of the Opel X17DTL diesel engine, it was found that using the traditional method of engine derating by installing additional gaskets between the cylinder head and block, the indicated specific consumption increased, on average, by 8–9 %. But with a decrease in the compression ratio of the engine by the proposed method due to late intake valve closing, the experimental value of the indicated specific consumption not only did not increase, but decreased, on average, by 7–8 %. The reduction of the compression ratio of the engine due to late intake valve closing by the proposed method was carried out by changing the shape of the camshaft cams. To this end, the cams of the intake valves were fused and then ground to the desired profile, with which late intake valve closing occurred within the predetermined limits.The results obtained allow optimizing the processes of conversion of diesel engines to gas and reducing the fuel consumption of converted engines, on average, by 15–17 % compared to gas engines converted in a traditional way