Study On Injection Coordinated Control Of Ethanol/Diesel Dual Fuel Engine

With the increasingly serious environmental pollution and the increasingly strict emission regulations,Reactivity Controlled Compression Ignition(RCCI)technology have attracted the attention of the majority of researchers.because of their ability to achieve high thermal efficiency while reducing NOx and PM emissions.In order to coordinate and control the reasonable injection between different fuels,the control strategy of dual-fuel engine is studied.Based on the self-developed dual-fuel electronic control system development and test platform,the influence of ethanol substitution rate on the performance of dual-fuel engine was analyzed in combination with bench test and calculation simulation,and the control strategy of ethanol substitution rate under different working conditions of dual-fuel engine was studied and verified.Firstly,the paper analyzes the technical lifting points and system requirements of ethanol/diesel dual-fuel engine,and builds the test bench of dual-fuel engine.Based on the development and testing platform of electric control system of ethanol/diesel dual fuel engine,the injection control of ethanol/diesel dual fuel engine based on calorific value conversion was designed to realize RCCI combustion of dual fuel engine,and the experimental study of ethanol substitution rate was carried out.At the same time,AVL FIRE software was used to establish the corresponding engine combustion chamber model to study the ethanol substitution rate.Finally,the control strategy of ethanol/diesel dual-fuel engine is studied and verified by combining the data of bench test and simulation.Simulation and experimental results show that the introduction of ethanol combustion in the engine,can decrease the temperature of the engine,increase the mixed working medium of the ignition delay period,is advantageous to the improvement of NOx and PM emissions: after the introduction of ethanol,dual fuel engine power performance than the original machine basically remain unchanged,exhaust gas temperature is reduced,effectively reduce the fuel consumption,improve the efficiency of the engine.Under low load,the introduction of ethanol will reduce the effective thermal efficiency of the engine and increase fuel consumption.Under medium and high load conditions,the proper introduction of ethanol can improve the effective thermal efficiency of the engine,increase the peak pressure in the cylinder and reduce fuel consumption.At 75% load,the boundary of ethanol substitution rate is 20%.At 90% loading,the boundary of ethanol substitution rate is 30%.The bench test verified the reliability and rationality of the control strategy of ethanol substitution rate.