Urea for diesel vehicles is used to reduce automobile exhaust emissions and protect the atmospheric environment. Urea is used in vehicles to reduce harmful nitrogen oxides in exhaust gas to nitrogen and water. Diesel vehicles equipped with urea system need a urea container to hold urea liquid, and ECU calculates the theoretical generation of nitrogen oxides according to engine speed, fuel injection and other data.

Then calculate the amount of ammonia needed to treat these nitrogen oxides according to the chemical reaction ratio, then calculate the amount of urea to be injected, and then control the injection system to inject urea into the high-temperature tail gas at the exhaust end to eliminate nitrogen oxides.

Matters needing attention in adding urea to freight cars

Most diesel engines use selective catalytic reduction technology. The general principle is that after the exhaust gas from the engine is discharged from the turbine, it directly enters the exhaust pipe and is converted by the catalytic converter. Then the urea nozzle on the exhaust pipe will spray urea aqueous solution under the control of the computer. Nitrogen oxides in urea aqueous solution and waste gas will undergo redox reaction in SCR catalytic converter, and finally waste gas will be reduced to unpurified nitrogen and water, and then discharged.

Never stop adding urea or shielding urea testing in order to save urea money. On the one hand, the automobile will limit the electricity when it detects that the emission is not up to standard, on the other hand, the urea system will be easily blocked if it is not used for a long time. I tried to add urea during the annual review, but found that the urea system was damaged because it was not used for a long time, and its maintenance cost was also very expensive, which was not worth the candle.