Shandong Lingong: Knowledge of National IV product accessories, let's take a look

As the implementation of the National IV emission standards for non-road machinery approaches,

Various types of construction machinery that meet the National IV emission standards have been successively launched on the market.

Today, I'll briefly share a few with you all

Some small facts about the parts of National IV vehicles

National Standard IV

National IV is the fourth stage of the national emission standards for pollutants from construction machinery. The main pollutants emitted by vehicles include HC (hydrocarbons), NOx (nitrogen oxides), CO (carbon monoxide), PM (particulate matter), etc. Through the application of technologies such as better active layers of catalytic converters, secondary air injection, and exhaust recirculation systems with cooling devices, Standards for controlling and reducing vehicle pollutant emissions to below prescribed values.

I. Tips for National IV Standards

When refueling, urea solution should also be added

Compared with National III vehicles, National IV vehicles mainly add exhaust gas treatment devices. Lingong products adopt a design scheme of diesel oxidation catalytic converter (DOC) + selective catalytic reduction device (SCR) + particulate filter (DPF). During operation, the vehicle constantly consumes urea solution, so in addition to refueling, urea solution needs to be replenished regularly.

Urea solution should be stored in an environment with a temperature ranging from -5℃ to 25℃, avoiding direct sunlight and intense exposure to the sun. High temperatures can shorten the warranty period of urea solution, while low temperatures can cause it to freeze and crystallize.

2. The grade of maintenance oil is high

The engine oil for vehicles meeting the National IV emission standards should be of CK grade or above.

3. The exhaust gas treatment device also needs regular maintenance

The maintenance details for National IV vehicles have added the urea pump filter element and the urea tank sensor filter element. Remember to replace the filter element of the exhaust gas treatment device regularly.

4. Unqualified fuel must not be added

Due to the advanced exhaust gas treatment equipment used in National IV vehicles, the requirements for fuel are relatively strict. If substandard fuel is used, it is easy to cause DPF blockage, DOC deterioration, SCR deterioration, thereby leading to reduced engine power, engine torque and speed limit, increased fuel consumption, excessive emissions, carbon deposits and black smoke, and even complete damage to components, which is not worth it.

Ii. National IV urea solution

In the urea tank of a vehicle that meets the National IV emission standards, vehicle urea is added. Under the action of the controller, it passes through the urea pump - metering supply device - urea injection device and is sprayed into the vehicle's fuel exhaust pipe. It mixes with the fuel exhaust and undergoes a chemical reaction. Then, it is filtered through the SCR catalytic converter to meet the National IV emission standards and the exhaust gas is discharged into the air. Therefore, it is a consumable that must be applied in construction machinery.

The hazards of inferior urea solution

Does the quality of urea solution have an impact on its use? The answer is inevitable. Next, I will introduce to you what hazards poor-quality urea can cause?

Harm 1

Damage the urea nozzle

The urea nozzle is located in the exhaust pipe and is constantly exposed to high temperatures. During operation, it is cooled through the circulation of urea water solution. If the cooling effect of the urea water solution is not achieved, the urea nozzle is prone to damage.

Harm 2

The metering pump is damaged.

Poor-quality urea water solution, with its concentration not meeting the standard, will lead to the occurrence of emission over-limit faults, ultimately manifested as an immediate reduction in engine torque, vehicle weakness, and an increase in the freezing point of the solution. In cold working conditions, it can cause the metering pump to freeze and be damaged.

Harm 3

Crystallization leads to "urea stones"

If urea is not used for a long time or inferior urea water solution is used, the crystallization of urea will clog pipelines, nozzles and pump bodies, causing local or entire system damage. In addition, in the exhaust gas treatment device, the ambient temperature where the nozzles are located is very high. Under normal operation, urea can play a certain cooling role. However, if the operation stops, it is very easy to burn out.

Hazard 4

Damage the urea pump

In fact, the production standards for urea water solution are strict. It is composed of 32.5% high-purity urea and 67.5% deionized water. Some enterprises, in order to reduce production costs, use ordinary water instead of deionized water. Urea water solution produced with non-deionized water will cause excessive impurity content, clog filters, urea solution delivery pipes and nozzles, and reduce the atomization effect of the SCR system. Excessive impurities can also damage the urea pump.

Influencing factors

The content of urea directly affects the catalytic efficiency of NOx and the freezing point of urea solution. In the SCR reduction system, the concentration of urea solution is one of the key factors. Excessively high or low concentrations not only fail to enhance the conversion efficiency of NOx but also cause ammonia loss (due to ammonia leakage caused by an excessively high NH₃/NOx ratio), resulting in the formation of secondary pollutants such as ammonia.

Alkalinity: Urea can hydrolyze to produce ammonia under the action of acid, alkali or enzymes (acid and alkali require heating). If the alkalinity is too high, it indicates that part of the urea is impure or has decomposed. This indicator controls the ammonia content in urea.

Biuret: During the production of urea, a by-product, biuret, is generated. Secondly, if it is not stored properly, the urea solution is prone to condense into biuret. Biuret, as an impurity in urea solution, should be strictly controlled.

Insoluble substances are impurities in urea solution that are insoluble in water. Their presence poses a risk of clogging the delivery pipes and nozzles of urea solution.

Lingong urea solution

Shandong Lingong urea solution is of high quality and high efficiency, suitable for long-term use in all models of Shandong Lingong complete machines and other complete machines of construction machinery. Core technology benefits society, and advanced technology leads the industry. The "Super Filtration System" is a urea solution technology independently developed by the designated supplier of Shandong Lingong. It is unique in the industry and a true anti-crystallization magic tool, allowing millions of construction machinery customers to use reliable urea solution.

Super filtration system

The purity of urea solution is an important indicator for distinguishing the quality of urea solution. Shandong Lingong's "Super Filtration System" for urea solution uses top-grade high-tech materials from Japan to achieve nano-level filtration of urea solution, with a filtration accuracy of 5-10 nanometers, approximately one ten-thousandth the thickness of a human hair. It effectively filters extremely fine colloidal substances such as biuret, slows down the generation of cyanuric acid products in the SCR system from the source, and keeps the SCR system's pipelines and nozzles clean. To achieve excellent atomization effect of urea solution, thorough exhaust gas treatment, reduce the consumption of urea solution, ensure strong engine power, and save fuel while increasing efficiency.