Research On Quantitative Analysis System For Combustion And Emission Performance Of Diesel Engine Under Steady And Transient Conditions

Conservation of non-renewable energy and protection of ecological environment are important links of sustainable development in the world today.Countries have put forward higher and higher requirements for the economic performance and emission performance of engines,and also formulated more and more strict standards.Whether the engine can save energy and reduce emissions largely depends on the combustion in cylinder.In order to analyze the combustion process of diesel engine better,this paper designed and developed a set of diesel engine combustion emission analysis system based on LabVIEW and MATLAB.The system considers the heat transfer and leakage loss in the working process of diesel engine and the model is adjusted and verified for the special starting condition.The system not only has the basic functions of parameter setting,data import and search,data mean processing,line smoothing,calculation and display,and data storage,but also supports continuous cycle analysis of transient and starting conditions,detailed numerical map analysis of steady-state single working conditions,and map analysis of multi-working conditions.In order to verify the practicability of the system,the data of a turbocharged diesel engine bench are processed and calculated.The combustion emission characteristics of diesel engine under different speed and load rate in steady state,the effects of different transition time and different constant speed on transient performance under constant speed and torque increasing transient condition,and the effects of different starting temperature on starting performance are compared and analyzed.Through the analysis,the combustion performance and the overall emission performance of the diesel engine are quite good at medium and high speed and load rate under all steady-state operating conditions.As the speed and load rate deviate from this region,the thermal efficiency decreases,and the effect of speed is more obvious.Under transient condition,combustion performance of diesel engine improves with the increase of transition time,constant speed and starting temperature.The practice shows that the system is simple in operation,diverse in function and stable in operation.It can help the relevant practitioners to analyze and study the rules and characteristics of the combustion and emission process of diesel engine conveniently and effectively,thus providing reference and guidance for improving the fuel economy of diesel engine and reducing pollutants,and achieving the expected engineering value.