Experimental Study On Bench Simulation Of Light Diesel Vehicle Emission

In recent years, diesel vehicles have a good market acceptance, Become the important models for the vehicle manufacturers to develop, especially for light diesel vehicle is the main vehicle of urban passenger and freight. Due to the limitation of vehicle development cycle and cost, we need to vehicle development and engine development with concurrent engineering, in order to continuously reduce calibration cost, shorten the calibration cycle, anticipate and avoid the risks.How to effectively carry out based on vehicle emissions and the other performance objectives of the assessment, emission calibration optimization, so as to reduce the workload of vehicle emission test, secondary engine thermodynamics development, bench calibration and reduce development risk has become a problem which needs to be solved urgently in the development of light-duty diesel vehicles, there are many technical difficulties for the development of light diesel vehicle, and the vehicle emission calibration is one of the important items.The main content of this thesis is to simulate the vehicle NEDC cycle emission test by using the engine bench steady states.the advantage of using the engine test bench to replace vehicle emissions test is that it can reduce the number of vehicle emission test in order to greatly shorten the development cycle and reduce development costs.Familiar with standard GB 18352.3-2005 "limits and measurement methods for emissions from light-duty vehicles(Chinese â…¢, â…£)" content, on the basis of vehicle emission test, obtaining fifteen cycle measurement parameters, find out the relationship between the change of vehicle emission with the vehicle driving conditions.The NEDC driving cycle in the vehicle emission test on the basis of the vehicle speed according to the cycle unit decomposition, engine speed and torque model is constructed according to the principle of vehicle dynamics, in order to get the engine equivalent condition model.After the establishment of engine equivalent condition model, ESC cycle and emission of the engine emission test cycle equivalent condition test on the engine test bench.In the processing of the test data, uses the concept of the contribution rate of pollutants, in order to analyze the effects of different conditions on vehicle emissions.Finally introduced theory of grey correlation degree, the vehicle emission test data and engine bench emission test data contact up, respectively engine equivalent conditions and ESC cycle with vehicle emission conditions between the correlation, so as to verify the correctness of the engine model of equivalent conditions.