Ptimization Design of Large-displacement Motorcycle Emission Testing Procedures

Abstract

Economic and/or practical points to be addressed The large-displacement motorcycles, which engine displacements above 600cc, usually have good acceleration, strong power and large heat dissipation. Due to strict emission requirements leads by the new China IV emission standards that give rise to various problems during tests cycles, and the existing testing facilities and conditions cannot fully meet the testing requirements for such motorcycles. Therefore, the test cycle for the emission of pollutants from large-displacement motorcycles needs to be optimized to further ensure the detection accuracy and better provide accurate data support for large-displacement motorcycles. Methodology China is currently implementing the China IV emission standards (GB 14622-2016, GB 18176-2016) for motorcycles. Compared with European Union IV emission standards, the most important feature is the durability assessment for actual pollution control devices. This paper makes a detailed comparative analysis for the limitation and detection method of the Type I test, Type II test, Type III test, Type IV test, Type V test and On-Board Diagnostics (OBD) system test for the large-displacement motorcycles, and designed an optimized emission testing technology for large-displacement motorcycle emission test procedures.</p><p class="font_7"><br></p> <p class="font_7">Main scientific and technical<br>Through the analysis for a large number of test results of large-displacement motorcycles, it is considered that they are similar to other types of motorcycles in single emission test procedures for type II test, type III test, type IV test, and OBD system test. However, special features are found in Type I test and Type-V test because of differences in displacement, acceleration and heat dissipation in large-displacement motorcycles. In consequence, it is necessary to optimize the testing technology to provide improvement in emission detection method to ensure the data accuracy. It is believed that the following factors will have an impact on the emission results and shall be strictly controlled and improved: 1. Impact from the fuel; 2. Impact from the driving behavior; 3. Impact from the testing equipment and the ambient environment during the test; 4. Impact from the vehicle maintenance during the test. Through a large number of motorcycle tests, it has been fully verified that the above four factors have significant impacts on the emission results. The research and verification carried out on the emission test of large-displacement motorcycles can determine how to optimize these four factors to ensure the data accuracy for the emission test of large-displacement motorcycles. Achieved results Several factors that impact the large-displacement motorcycles emission test have been fully verified, indicating that the test procedures need to be precisely optimized that suggesting for testing procedures are summarized and given in the following four factors, thereby reducing emission detection errors and ensuring the test accuracy. 1. Standardized training method for the driver 2. Environmental condition control method 3. Environmental background gas concentration control method 4. Fuel control method and requirements