SHACMAN winter warm tips – urea use rules

Winter car urea liquid will freeze? What about freezing? Do you want to add antifreeze low temperature urea?


As soon as the temperature drops in winter, many car owners, especially in the north, will inevitably worry about their urea tank freezing, they will ask whether the car urea will freeze, how to freeze it, whether to add the landlord low-temperature urea and other problems, and some car owners directly replace the ordinary urea solution with a urea solution of -35 ° C, thinking that this is easy, in fact, it is not. It not only costs money but also easily damages the vehicle’s aftertreatment system. Now let’s popularize the basic common sense.

Why add urea solution?
What’s the harm in not adding?
The so-called vehicle urea solution, also known as diesel exhaust treatment liquid, refers to a urea solution with a urea concentration of 32.5% and a solvent of ultra-pure water, and its raw materials are urea crystals and ultra-pure water. It is installed in the urea tank, when the exhaust pipe is found to have nitrogen oxide, the urea tank automatically ejects the vehicle urea solution, and the two REDOX reactions occur in the SCR reaction tank, generating pollution-free nitrogen and water discharge, reducing emissions.


SCR system working principle: With the popularity of national four, national five, and even later national six cars, automotive urea can be said to be an essential additive for SCR, and it is also an essential product for diesel vehicles such as trucks and buses to meet national five and six emission standards.

Not adding urea solution for a long time, or using pure water or tap water instead, will cause great damage to the urea nozzle and even the entire post-treatment system. To know that the replacement of urea nozzle is often thousands of yuan, the entire system needs 30,000 to 50,000 yuan.

What is -35℃ vehicle urea solution?
Do you want to add a low temperature urea solution?
The vehicle urea solution stipulated by the national four countries five emission standards begins to freeze at a normal temperature below -11 ° C. Individual manufacturers use additives (ethanol or ethylene glycol) to reduce the freezing point of automotive urea, so as to achieve the purpose of anti-freezing. However, the ethanol in the additive is flammable and explosive, and the vehicle exhaust pipe is at high temperature, if the ethanol concentration is too high, it will cause damage to the exhaust pipe. Under certain temperature conditions, ethylene glycol will produce acid substances, which will cause corrosion on the exhaust pipe and cause leakage. Therefore, there is no need to use the so-called -35 ° C automotive urea solution, and more importantly, the -35 ° C automotive urea solution is about 40% more expensive than the ordinary one on the market.


Does urea solution freeze in winter?
What if I get cold?
Does urea solution freeze in winter? What if I get cold? In fact, these problems, manufacturers have long considered, generally need to antifreeze the northern version of the vehicle SCR system are equipped with urea tank thaw heating function, when the engine water temperature reaches 60 degrees, urea liquid temperature is lower than -5 degrees Celsius, from the engine pump to the urea tank engine coolant will open the circulation flow, in order to thaw the urea liquid crystallization in the urea tank.

Since SCR needs the engine exhaust temperature to reach more than 200 ° C to enter the work, urea liquid will not be sprayed at a low temperature, so as to provide sufficient time for the thawed crystallized urea liquid.

Therefore, there is no need to worry about whether the urea solution will freeze, and how to do after freezing. In addition, even in the coldest regions, there is no need to add so-called low-temperature urea solution.

Published by:Wenrui Liang

Post time: Feb-20-2024