Research On The Implementation Of The Urea Supply System For China Ⅳ Heavy-duty Diesel Vehicles

With the rapid development of China’s economy, Vehicle production and ownership growing fast, the Pollution caused by vehicle exhaust growing people’s concern. According to the2010Annual Report released by the Ministry of Environmental Protection, the survey on vehicle pollution in major cities shows vehicles have become the most important urban air pollution, the contribution rate is far more than other sources. Although the amount of heavy-duty vehicles only take5%of total vehicle ownership, NOx and PM emissions to total emissions accounted for74%and86%, so it is the focus of control. Therefore strengthen the control of emissions from heavy-duty diesel vehicles, improve the emission standards, at this stage it is an optimal means in the view of cost-effective in environmental.Our country will be fully implemented China IV emission standards for heavy-duty vehicles in2013. And it will take two kinds of after-treatment system technical route, one is the SCR; the other is the EGR+DPF. Both technical routes are widely used internationally, United States take EGR as a major route, Europe take SCR as major route. China will adopt SCR technology as a mainstream route. SCR after-treatment system needs to raise urea solution, the ammonia which is decomposition by urea solution will be used as a reducing agent, it will reacts with NOx and generate N2. Therefore,to ensure a sufficient supply of the high quality urea solution is a key fator which can ensure the smooth implementation of China IV emission standards for SCR heavy-duty vehicles.The paper take Beijing as a study case and will mainly research from the following four aspects:(1)The needs and development analysis of urea solution in BeijingInclude:Estimate on the ownership of China IV heavy-duty diesel vehicles, estimate annual consumption of urea solution for each vehicle, estimate the annual needs of urea solution after implemented the China IV standard, analysis the cost and benefit of urea solution; (2)The urea supply program in BeijingInclude:Plan for urea supply program in Beijing, modes of urea supply in Beijing, the distribution methods of urea solution in Beijing, requirements on the establishment of urea solution filling system at gas station;(3) Impact assessment between the quality of urea solution and the normal operation of SCR systemInclude:Running test of SCR system in extreme weather conditions and storage test of the urea solution at abroad, actual usage of urea solution for Beijing bus fleet under normal operating conditions, the reduction ratio impact for urea solution products of different manufacturers to pollutants NOx, the concentration of urea effects on NOx emissions;(4)The regulatory proposals of urea solution supply systemInclude:The regulatory for production suppliers, the regulatory for production distributor, the regulatory for end users of urea solution.Beijing as a demonstration area for China’s environmental protection and advanced implementation of the previous standard, This paper can proposed a supply program of urea solution by carrying out research work on the urea solution supply system for China Ⅳ heavy-duty diesel vehicles in Beijing. It has universal significance at other major cities or nationwide to promote the China Ⅳ heavy-duty diesel vehicles emission standards.