Simulation Research On Power Performance Of Hydrous Alcohol Reforming Fuel Engine

The hydrous-ethanol reforming fuel engine has the characteristics of using renewable ethanol fuel,and the reformed fuel contains hydrogen-rich gas which is helpful for the combustion of the engine.It is one of the most promising new energy engines.However,compared with the prototype gasoline engine,the power performance of the hydrous-ethanol reforming fuel engine is significantly reduced due to various reasons.Therefore,to optimize the power performance is crucial for the development and application of the hydrous-ethanol reforming fuel engines.In this thesis,the LJ4K18 QS gasoline/hydrous-ethanol reformed gas dual-fuel engine is taken as the research object.A combination of experiments and simulations is applied to study the multi-factor such as ignition advance angle,air-fuel ratio,gas distribution phase,and additional ethanol vapor.First,the power performance of the hydrous-ethanol reformed fuel engine and its influencing factors were analyzed and evaluated.Then,the simulation models of the LJ4K18 QS gasoline engine and the hydrous-ethanol reformed fuel engine were established based on GT-Power,and the engine test bench was built.And reformed gas component test system and the simulation model was verified by experimental data.Finally,based on the DOE experimental method to simulate and analyze the external characteristics of the selected operating speed by the combination of ignition advance angle,air-fuel ratio and valve timing phase.The influence of factors and their sensitivity analysis were carried out,and a multi-factor combination based on the maximum output torque was obtained.At the same time,based on the optimized operating parameters,the feasibility of further increasing the power of the hydrous-ethanol reformed fuel engine with additional injection of ethanol vapor was discussed.The research results show that the three operating parameters as ignition advance angle,air-fuel ratio,and gas distribution phase at different speeds have similar effects on the dynamics: within the operating speed range,the torque and the power increase first and then decrease.The fuel consumption rate decreases first and then increases.Compared with the operating parameters before the optimization,the torque of the external characteristics of the engine after optimization has been increased by 8.9% on average,and it is more obvious at low speeds.The maximum increase is 16.9% at1200r/min.Multi-factor sensitivity analysis shows that the air-fuel ratio has the greatest effect on the external characteristic torque;the additional enriched ethanol vapor also has an effect on the power of the hydrous-ethanol reformed fuel engine.And additional concentrated ethanol steam has a significant effect on the dynamics of hydrous-ethanol reformed fuel engines.With the amount of ethanol steam injected increases,the external characteristic torque of the engine increases first and then decreases.Compared to non-enriched,the torque of a suitable enriched ethanol steam engine at each speed increased by 2.6% on average,and the maximum increase at 4400 r / min,reaching 3.6%.The research results of this paper can provide valuable reference for the development of control strategy and performance optimization for the subsequent operation parameters of hydrous-ethanol reforming fuel engines.