Study On The Characteristics Of Biodiesel For Motor Vehicles By Urban Buses

The pollutants generated by internal combustion engines have become a crucial part of air pollution.It is imperative to popularize the use of alternative fuels with abundant sources,renewable and low pollution.Mixing an appropriate proportion of biodiesel in vehicle diesel can be directly applied to ordinary diesel buses while reducing pollutant emissions,making it an ideal diesel alternative fuel.Therefore,it can reduce China’s dependence on fossil resources.Moreover,it can also effectively reduce environmental pollution in large and medium-sized cities of China.In order to promote the joint prevention and control of regional air pollution and promote the use of biodiesel,experimental research was carried out.The test is based on the C-WTVC cycle.The MAHA heavy-duty chassis dynamometer and HORIBA test system are used to compare and analyze the six diesel buses that meet the national IV and national V emission standards,respectively,using the national V diesel,Jing VI diesel and Jing VI.The general emission characteristics of conventional pollutants and the common emission characteristics of unconventional pollutants when diesel fuel is blended with 5%biodiesel blended fuel（abbreviated as B5 vehicle diesel）,and the unconventional pollutant discharge characteristics under different actual operating conditions.The research results show that B5 diesel fuel has higher oxygen content and higher cetane number,which can make the fuel burn more fully.At the same time,B5 vehicle diesel also has lower aromatic hydrocarbon content and sulfur content,which can reduce the pollutant emissions.After using B5 diesel fuel,the emission of conventional pollutants such as CO,HC and PM fully showed a decreasing trend.The average decline of the six prototypes under three different endurance mileage was 6.80%,10.88%and 9.81%respectively.The emission of unconventional pollutants 1,3-C₄H₆,C₆H₆ and HCHO showed a decreasing trend,and the average declines of the four prototypes under 3 different endurance mileage was 20.53%,7.67%and 14.92%,respectively.In addition,the reduction trend of the national IV prototype is more obvious than that of the national V prototype.The emission of conventional pollutant NOx showed an increasing trend as a whole.The average increase of 6 prototypes under three different endurance mileage was 6.71%,and the increasing trend of the national IV prototypes was more obvious than that of the national V prototypes.However,the PN emissions of vehicles are unstable,so this article is still unable to make a conclusion.The emissions of unconventional pollutants NH₃,SO₂ and C₇H₈ also showed a decreasing trend as a whole.After burning B5 diesel fuel,the average emission of NH₃ is the most obvious under high-speed conditions;the average emission of C₇H₈ is the most obvious under medium-speed conditions;the average emission of SO₂ is the most obvious under idle conditions,but its average emissions are increased under high-speed conditions.The research results in this paper have critical significance for the promotion of B5diesel fuel,and have significant reference value for the future development of non-conventional pollutant emission standards.