Numerical Analysis Of The Work Process For A High-powered LNG Engine

With the grimness of energy crisis and emission regulations of vehicle day by day, as clean energy, the natural gas has became a kind of important substitutable fuel of the engine. Because of the physical and chemical characteristic of natural gas, some problems of CNG/LNG engine are waiting to be solved and researched. This paper took the high powered and supercharged EQRN400-30LNG engine as the object to study, carried on numerical simulation of the work process, and analyzed the influence of relative parameter to the engine.After introduced the background of this study and the mathematical models of work process briefly, a EQRN400-30LNG engine's computation model was established by AVL BOOST, and confirmed the accuracy of the model based on correlation data of testing. Then discussed the method of computation and choice to turbocharger by AVL BOOST, and had selected the appropriate compressor for this engine. Finally,carried on computing and optimizing to the compression ratio, ignition time, air-fuel ratio, valve timing of the LNG engine. Analyzed that how these parameters influenced the engine's performance parameter such as the power, torque, BSFC, discharge temperature, highest explosion pressure, temperature before turbine wheel, emission rate of NOx. at last, proposed some suggestion of optimization and improvement.The result of numerical simulation indicated that the LNG engine could achieve the request of anticipated power and the torque after optimization, and engine's BSFC and heat load were all reduced, other performance parameter were also in the permissive scope, the performance of the whole engine had obtained certain promotion. It would provide the valuable reference for the design and experiment in the future.