Vehicle urea must use first-class ultra-pure water in electronic industry. Because the SCR catalyst carrier is prone to metal ion poisoning and thus loses its catalytic function, the automobile urea solution must use ultra-pure water from the electronics industry.
Vehicle urea solution will start to freeze at-1 1℃, and it will completely freeze at -20℃ in actual use. At present, the technology is to reduce the freezing point of the solution by adding modifiers, and to prevent the solution from freezing by adding heating devices.
Extended data
SCR system includes urea tank (containing diesel exhaust treatment liquid) and SCR catalytic reaction tank. The working process of SCR system is as follows: when nitrogen oxides are found in the exhaust pipe, the urea tank automatically sprays diesel tail gas treatment liquid, and the diesel tail gas treatment liquid and nitrogen oxides undergo redox reaction in the SCR catalytic reaction box to generate pollution-free nitrogen and water vapor.
If diesel exhaust treatment liquid is not loaded, or the purity is not enough, or the quality is poor, the vehicle engine will automatically slow down. At the same time, inferior diesel exhaust treatment liquid will pollute the catalyst in SCR catalytic reaction tank, causing serious consequences.
Baidu encyclopedia-automobile urea solution
Baidu encyclopedia-urea solution for vehicles