JB/T 11880.5-2014Diesel Engines - Selective Catalytic Reduction (SCR) Systems - Part 5: Urea Solution injectors (English PDF)

3.1 Urea solution injector

A device for injecting urea solution into the exhaust pipe of an engine, which includes two types: an air-assisted urea solution injector and an airless urea solution injector.

3.2 Airless urea solution injector

A device in which a certain amount of urea solution is directly injected into the exhaust pipe of the engine by a control valve.

3.3 Airless urea solution injector assembly

5.1 Technical requirements for airless urea solution injectors

5.1.2.2 Torsion strength

5.1.2.2.1 Apply a torsion torque of 6.0 N · m to both ends of the injector assembly; the injector shall not be deformed after 5 s.

5.1.2.2.2 After the test, the tightness of the injector shall meet the requirements specified in 5.1.8; the flow consistency shall meet the requirements specified in 5.1.13.

5.1.2.3 Bending strength

5.1.2.3.1 Simultaneously apply a bending moment of 4.0 N · m to both ends of the longitudinal axis of the injector assembly; it shall not deform after 30 s.

5.1.2.3.2 After the test, the tightness of the injector shall meet the requirements specified in 5.1.8; the flow consistency shall meet the requirements specified in 5.1.13.

5.1.3 Vibration resistance

5.1.3.1 During the vibration test, there shall be no damage to the parts of the injector and no loosening or falling off of the fasteners.

5.1.3.2 After the test, the tightness of the injector shall meet the requirements specified in 5.1.8; the flow consistency shall meet the requirements specified in 5.1.13.

5.1.4 Pressure resistance

5.1.4.1 During the pressure resistance test, there shall be no deformation or rupture of the injector.

5.1.4.2 After the test, the tightness of the jet injector shall meet the requirements specified in 5.1.8; the consistency of the flow view shall meet the requirements specified in 5.1.13.

5.1.5 Salt spray resistance

5.1.5.1 After the salt spray test, the outer surface of the injector shall be clean and there shall be no signs of corrosion.

5.1.5.2 After the test, the tightness of the injector shall meet the requirements specified in 5.1.8.

5.1.6 Resistance to industrial solvents

5.1.6.1 After the end of the industrial solvent resistance test, there shall be no corrosion marks, cracks, discoloration and other abnormal phenomena on the outer surface of the injector.

5.2 Technical requirements

for air-assisted urea solution injectors

5.2.1 General requirements

5.2.1.1 The appearance of the injector shall not have defects such as rust spots, knocks, etc. The size of the injector shall be manufactured in accordance with the product drawings and technical documents approved by the prescribed procedures.

5.2.1.2 The parts of the injector shall be complete, and the trademark shall be clear.

5.2.1.3 When using the urea solution for vehicles as specified in ISO 22241-1, the injector shall work normally.

5.2.1.4 The fluid piping joints of the injector meet the requirements of SAE J2044.

5.2.2 Strength performance

5.2.2.1 Apply an axial pressure of 600 N to the longitudinal axis of the injector, the injector shall not be deformed after 60 s.

5.2.2.2 Apply a torsion torque of 6.0 N · m at both ends of the injector, the injector shall not be deformed after 5 s.

5.2.2.3 Simultaneously apply a bending moment of 4.0 N · m at both ends of the longitudinal axis of the injector, the injector shall not be deformed after 30 s.

5.2.3 Vibration resistance

After the vibration test, there shall be no damage to parts and fasteners; there is no loosening or falling off of fasteners.

5.2.4 Pressure resistance

The inside of the injector shall be able to withstand 1.5 times the maximum working pressure for 1 min. During the test, the injector has no deformation or rupture.

5.2.5 Salt spray resistance

After the salt spray test, the outer surface of the injector is clean and there is no trace of corrosion.

6.1 Test method for injector for airless urea solution

6.1.4.3.1 Install the injector assembly on the bending moment test bench. Apply a bending moment of 4.0 N · m to the injector assembly for 30 s.

6.1.4.3.2 Observe whether the injector is deformed.

6.1.4.3.3 Then carry out the tests as specified in 6.1.10 and 6.1.15.

6.1.20.1 The electromagnetic immunity test of the injector shall be carried out in accordance with the relevant requirements of GB/T 17619.

6.1.20.2 The electromagnetic disturbance test of injector is carried out in accordance with the relevant requirements of GB 18655.

6.1.5 Vibration resistance test

6.1.5.1 According to the provisions of GB/T 2423.10, fix the injector assembly on the vibration test bench according to the normal installation position; perform the sinusoidal vibration test in the three directions of X, Y, Z.

6.1.5.2 Under the conditions of 10 Hz ~ 2000 Hz random frequency conversion and 30 g acceleration, perform longitudinal and lateral vibration for 48 h

6.1.5.3 After the end of the test, observe whether the parts of the injector assembly are loose; then perform the tests as specified in 6.1.10 and 6.1.15.

6.1.6 Pressure resistance test

6.1.6.1 Connect the injector inlet to the hydraulic test bench; start the test bench to slowly increase the pressure to 1.5 times the maximum working pressure; hold this pressure for 1 min.

6.1.6.2 Observe whether the injector is deformed or broken.

6.1.6.3 After the end of the test, perform the tests as specified in 6.1.10 and 6.1.15.

6.1.7 Salt spray resistance test

6.1.7.1 Carry out the salt spray resistance test according to GB/T 10125.

6.1.7.2 Place the injector assembly in the salt spray chamber for continuous 96- hour salt spray resistance (sodium chloride solution with a mass fraction of 5%) test.

6.1.8 Industrial solvent resistance test

6.1.8.1 Carry out test in accordance with the requirements of the corresponding test method in GB/T 2423.30.

6.1.8.2 The recommended reagents are vehicle urea solution, brake fluid, engine oil, diesel oil or glass cleaner. The test chemical reagents shall be negotiated and determined by the supplier and the user.

6.1.8.3 The reagent temperature is 20 °C ~ 30 °C; the injector is immersed in the reagent for 24 hours.

According to the provisions of the corresponding test method of Be in GB/T 2423.2, set the test environment temperature to 80 °C, to perform the tests as specified in 6.1.10 and 6.1.15.

6.1.13.2 Low-temperature resistance test

According to the provisions of the corresponding test method of Ae in GB/T 2423.1, set the test environment temperature to -40 °C to perform the tests as specified in 6.1.10 and 6.1.15.

6.1.14 Flow linear deviation test

6.1.14.1 The reagent is vehicle urea solution; the temperature is 20 °C ~ 30 °C. Randomly take 10 injector samples.

6.1.14.2 The pressure of the urea solution is the rated working pressure; the injector pre-sprays 1000 times.

6.1.14.3 Set the duty cycle to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%; measure the urea solution injection volume of 2000 consecutive injections of the injector.

6.1.14.4 Use the least square method to simulate the test data. Calculate the flow linear deviation of the injector.

6.1.15 Flow consistency test

6.1.15.1 The reagent is a urea solution for vehicles with a temperature of 20 °C ~ 30 °C. Randomly take 10 injector samples.

6.1.15.2 Install the injector on the flow test bench and set the duty cycle to 10%; the injector continuously sprays 2000 times under the rated working pressure.

Use a utensil or a flow meter (the accuracy level is not less than 4) to measure each spray volume.

6.1.15.3 Set the duty cycle to 20%, 30%, 40%, 50%, 60%, 70%, 80%. Replace the injector. Repeat the above test. Obtain the flow consistency deviation under each duty cycle.

6.1.16 Noise test

According to the relevant provisions of GB/T 16538-2008, measure the sound power level of the injector's noise under the rated working pressure.

6.1.17 Spray test

6.1.17.1 According to the provisions of GB/T 25363, install the injector on the fixed support. Adjust the distance h from the injector nozzle to the center of the […]

6.1.21 Cleanliness test

6.1.21.1 Randomly select 10 samples of the injector. The filter membrane uses a 0.45 µm and 5 µm microporous membrane with a diameter of more than Phi 50 mm. The cleaning solution complies with the class-1 reagent oil as specified in SH 0004. The accuracy class of the weighing analytical balance (0.1 mg) is class 3.

6.1.21.2 The method of non-disassembly is adopted for the measurement. The sampling location is the internal surfaces of the injector (including the needle valve surface). Clean the outer surface of the pipeline, all sampling tools, supports, containers, injectors. Install the injector on the test bench. The cleaning solution entering the injector is first filtered through a 0.45 µm filter membrane. The injector sprays 2000 times at a 50% duty cycle. Collect the sprayed cleaning solution in the container. Use tweezers to place the weighed 5 µm microporous filter membrane for use in the clean solution to moisten it.

Place it on the sand core of the filter device. Perform suction filtration of the cleaning solution with impurities.

6.1.21.3 After the washing solution evaporates, put the filter membrane with impurities in an electric thermostatic drying oven at a temperature of 90 °C ± 5 °C for 1 h. Then take it out. Place it in a drying container to cool for 30 min.

Use a balance to weigh the impurities to get the mass of the impurities. After drying and weighing twice, the second time shall prevail (the difference between the two dryings is not more than 0.4 mg).

6.1.21.4 After weighing, use a measuring magnifying glass to measure the size of the largest particle. Take another injector and repeat the test.

6.2 Test method for air-assisted urea solution injector

6.2.6.3 Observe whether the injector is deformed or broken.

6.2.11.5 After weighing, use a measuring magnifying glass to measure the size of the largest particle. Take another injector and repeat the test.

6.2.1 Test conditions

6.2.1.1 Unless there are special requirements, the injector test shall be carried out in accordance with the requirements as specified in GB/T 25363 under the following environmental conditions: the ambient temperature is 20°C ~ 30°C; the relative humidity is 25% ~ 65%; the air pressure is 101.3 kPa ± 5 kPa

6.2.1.2 The vehicle urea solution used for the test shall be implemented in accordance with ISO 22241-1.

6.2.7 Salt spray resistance test

6.2.7.1 Carry out the salt spray resistance test according to the requirements of GB/T 10125. The injector does not work during the test.

6.2.7.2 Place the injector in the salt spray box for continuous 96-hour salt spray resistance (sodium chloride solution with a mass fraction of 5%) test.

6.2.8 Industrial solvent resistance test

6.2.8.1 Carry out test according to the requirements of the corresponding test methods in GB/T 2423.30.

6.2.8.2 It is recommended to use vehicle urea solution, brake fluid, engine oil, diesel oil or glass lotion. The chemical reagents used in the test shall be negotiated and determined by the supplier and the user.

6.2.8.3 The temperature of the reagent is 20 °C ~ 30 °C. The injector is immersed in the reagent for 30 min.

6.2.9 Spray test

6.2.9.1 Randomly sample 10 injectors. The reagent is a urea solution for vehicles; the temperature is 20 °C ~ 30 °C; the injection pressure is the rated working pressure.

6.2.9.2 Install the injector on the support of the laser particle size tester. Make the nozzle of the injector downward. Adjust the distance h from the nozzle of the injector to the center of the test source to be 75 mm ± 1 mm, as shown in Figure 3.

6.2.9.3 Randomly detect the diameter of 10000 droplets from the collected droplets and record the data.

6.2.10 Spray cone angle test

6.2.10.1 There are 6 test injector samples. The reagent is a vehicle urea solution. The temperature is 20 °C ~ 30 °C.

6.2.10.2 According to the provisions of GB/T 25363, install the injector on the spray test bench, so that the nozzle of the injector is downward. Perform spray under the rated working. Use calculation method or measurement method to obtain spray cone angle.

6.2.12 Flow consistency test

6.2.12.1 Randomly sample 10 injectors. The reagent is a urea solution for vehicles. The temperature is 20°C ~ 30°C. The accuracy level of the flowmeter is not lower than level 4.

6.2.12.2 Install the injector on the flow test bench and connect the flowmeter.

After the flow is stable, measure the flow of the injector for a duration of 2 min.

The pressure of the urea solution in the test is the rated working pressure.

6.2.12.3 Record the test results. Replace the injector, to perform the next test. Finally calculate the injector's flow consistency deviation.

7.1 Qualified documents and marking

Each injector product can only exit-factory after passing the inspection and being accompanied with the product quality certificate or mark.

7.2 Product inspection category

Product inspection is divided into exit-factory inspection, type inspection, sampling inspection.

7.3 Exit-factory inspection

The inspection items, technical requirements and test methods for the exit-factory inspection of the airless urea solution injector shall be in accordance with Table 1.

The inspection items, technical requirements and test methods for the exit-factory inspection of the air-assisted urea solution injector shall be in accordance with Table 2.

7.4 Type inspection

In one of the following situations, the manufacturer shall carry out type inspection: […]