JB/T 11880.4-2014Diesel Engines - Selective Catalytic Reduction (SCR) Systems - Part 4: Urea Solution Supply Pump (English PDF)

3.1 Urea solution supply pump

It is a device for delivering urea solution to the urea ejector, including air-assisted urea pump and airless-assisted urea pump.

3.2 Air-assisted urea solution supply pump

This is a device that will have a precisely metered urea solution delivered to the urea injector under the assistance of air, which has supply and metering functions.

3.3 Airless-assisted urea solution supply pump

5.7 High-and-low temperature resistance (if there is heating function)

5.7.1 Low temperature resistance

The urea pump is placed in a high-and-low temperature test chamber. At a temperature of -40 °C ± 2 °C, perform the low temperature test of 48 h (24 h low temperature storage, 24 h low temperature operation). After the test is over and return to normal temperature, the performance meets the requirements of 5.3.

5.7.2 High temperature resistance

The urea pump is placed in a high-and-low temperature test chamber. At a temperature of 70 °C ± 2 °C, perform the high temperature limit test of 144 h (48 h low temperature storage, 96 h low temperature operation). After the test is over and return to normal temperature, the performance meets the requirements of 5.3.

5.7.3 Resistance to temperature changes

The temperature change test of the urea pump is carried out in accordance with the provisions of the test Na in GB/T 2423.22. During the test, the low temperature is -40 °C and the high temperature is 85 °C. The exposure time in each temperature is 1 h; the temperature conversion time is 20 s ~ 30 s; the number of cycles is 5. After the test is over and return to normal temperature, the performance meets the requirements of 5.3.

5.7.4 Resistance to combined cyclic temperature/humidity change

The urea pump shall be subjected to 10 cycles of combined cyclic temperature/humidity test between -10 °C and 65 °C in accordance with the provisions of GB/T 2423.34, each cycle time is 24 h. It does not work at low temperature segment. Turn on the urea pump at high temperature segment.

After the test is over and return to normal temperature, the performance meets the requirements of 5.3.

5.8 Heating function (if any)

The urea pump is placed in the high-temperature test chamber, energized to work, cut off power after normal operation. Start the urea pump after storing for 8 hours under the temperature condition of -40 °C ± 2 °C. The urea pump can reach normal working condition after 45 minutes. After the test, the performance meets the requirements of 5.3.

Reversal of voltage value: 14 V ± 0.2 V for 12 V electrical system; 28 V ± 0.2 V for 24 V electrical system. After the test, the performance meets the requirements of 5.3.

5.13 Abnormal power supply voltage resistance

5.13.2 Withstanding power supply overvoltage

The urea pump shall be subjected to an overvoltage test in accordance with the provisions of 6.13.2, to confirm its ability to not be damaged under the power supply overvoltage condition.

12 V system: It is capable of withstanding 18 V voltage for 60 min. After the test is over, the performance meets the requirements of 5.3.

24 V system: It is capable of withstanding 36 V voltage for 60 min. After the test, the performance meets the requirements of 5.3.

5.14 EMC performance

5.14.1 Radiation immunity

The urea pump is subjected to the radiation immunity test in accordance with 6.14.1; the product has no damage after the test. Performance meets the requirements of 5.3.

5.14.2 Electrostatic discharge interference test

The urea pump is subjected to electrostatic discharge interference test in accordance with 6.14.2; the product is not damaged after the test. Performance meets the requirements of 5.3.

5.14.3 Electromagnetic disturbance

The urea pump is subjected to the electromagnetic disturbance test according to the provisions of 6.14.3; the test result reaches the level 3 as specified in GB/T 18655.

5.15 Withstanding voltage performance of insulation

Between the non-connected conductive parts of the urea pump and between the conductive parts and the housing, it shall be able to withstand 50 Hz, 550 V (effective value) sine wave voltage test for 1 min, during which the insulation is not breakdown. In mass continuous production, a test with a voltage of 660 V and a duration of 1 s can be used instead. After the test, the performance meets the requirements of 5.3.

It is performed according to the corresponding test method of the test Ad (low temperature test with gradual temperature gradient of heat dissipation test sample - the test sample is energized after the temperature starts to stabilize) in GB/T 2423.1.

6.7 Test of high-and-low-temperature resistance

6.7.2 Test of high temperature resistance

It is performed according to the corresponding test method of the test Bd (high temperature test with gradual temperature gradient of heat dissipation test sample - the test sample is not energized during the regulating period of temperature rise) in GB/T 2423.2.

6.7.3 Test of temperature change resistance

It is performed according to the corresponding test method of test Na (fast temperature change test with specified conversion time) in GB/T 2423.22.

6.7.4 Combined cyclic temperature/humidity test

It is performed according to the relevant requirements of the test Z/AD (combined cyclic temperature/humidity test method) in GB/T 2423.34.

6.8 Heating function test

The urea pump is placed in the high-and-low-temperature test box. It is powered off after normal operation. After storing for 8 hours at a temperature of 40°C ± 2°C, start the urea pump to enter the heating state. Monitor the pressure and temperature changes through the pressure sensor and temperature sensor.

The urea pump can enter the normal working state after continuous heating for 45 minutes.

6.9 Protection performance test

6.9.1 Anti-solid foreign matter performance test shall be carried out in accordance with the corresponding test method of IP6X in GB 4208.

6.9.2 The waterproof performance test shall be carried out according to the corresponding test method of IPX6 in GB 4208.

Use the nozzle test to spray water on the tested shell in all possible directions. The test conditions are as follows:

a) Nozzle's inner diameter: 12.5 mm;

b) Water flow rate: (100 ± 5) L/min; It is performed according to the provisions of GB/T 19951.

6.14 Electromagnetic compatibility test

6.14.3 Electromagnetic disturbance test

It is performed according to the relevant provisions of GB 18655.

6.15 Insulation withstanding voltage test

6.15.1 The test is only carried out on the products whose parts are in normal condition after the new assembly. During the test, apply a sinusoidal voltage of 550 V (effective value) and a frequency of 50 Hz ~ 60 Hz for 60 s. In mass continuous production, a test with a voltage of 660 V and a duration of 1 s can be used instead. The requirements are as follows:

- Between terminals with electrical insulation;

- Between the terminal with electrical insulation and the housing with electrical conduction surface;

- (In the case of a plastic housing) between the terminal and the electrode wrapped in the housing (such as metal foil).

6.15.2 When semiconductor devices (diodes, transistors, integrated circuit blocks, etc.) are installed in the product, then, these devices shall be disconnected, or the withstanding voltage test shall be carried out before assembling the devices.

6.15.3 The products that have been installed and used and have undergone endurance tests are not subject to insulation withstanding voltage test.

7.1 Inspection category

Urea pump inspection is divided into exit-factory inspection, sampling inspection, type inspection.

7.2 Exit-factory inspection

Each urea pump shall be inspected and qualified, and the product inspection certificate shall be attached before leaving the factory. The inspection items, technical requirements and test methods of the exit-factory inspection shall be in accordance with Table 5. […]