Xingtai vehicle urea water manufacturer of diesel full implementation of the national IV emission standards, automobile manufacturers to upgrade the country's four main lines are using SCR technology, which means that to achieve the national IV emission standard must add car urea. However, considering the car, after all, the use of urea is a new thing, a lot of people are still lack of knowledge, or that there are some errors on the use, and therefore, the author here to give readers some simple car presentation urea matters, We hope everyone can provide useful lessons. The main pollutant emissions of diesel engines are NOx (nitrogen oxides) and PM (particulate), required to reduce emissions of these two operating conditions are exactly the opposite, and therefore, there has been EGR (exhaust gas recirculation) and SCR (selection catalytic reduction) are two technical solutions to meet the requirements of China IV emissions. Adopt SCR technology roadmap engine combustion process, has made diesel combustion by technical means to achieve effective control of PM emissions targets, and nitrogen oxides NOx in the exhaust gas is required in the process of reducing its nitrogen (N2 ) and water (H2O), this process is reducing vehicle urea solution. When injected into the urea solution into the exhaust pipe from the exhaust turbocharger out of the exhaust pipe is installed metering urea injection device, at temperatures up to 300 ℃ -500 ℃, in the catalyst of urea (NH2CONH2) hydrolysis NH3 and CO2, NH3 and NOx reaction of nitrogen and water discharge. I use urea project responsible person learned from the car Daka blue pigment portion, car catalytic reduction with urea solution in the control is a very refined process, the amount of urea injected into the match must be the NOx concentration , the amount of injected urea is too small, the treatment should not reach the level of the excess amount of urea injected, will cause the excess ammonia into the atmosphere, resulting in new pollution. Vehicle urea solution in Europe called Adblue, in North America called DEF (Diesel Exhaust Fluid, namely diesel exhaust treatment liquid), in the country called the car with urea solution or "Tim Blue." Car purity and cleanliness requirements urea solution is higher, relative to the content of industrial urea, biuret, insoluble materials, iron, sulfides, chlorides, etc. There are strict requirements.