GB/T 26990-2023Fuel cell electric vehicles—Onboard hydrogen system technical specifications (English PDF)

3.1 Onboard hydrogen system

On fuel cell electric vehicles, from the hydrogenation port to the pressure regulator, devices related to hydrogen filling, storage, transportation, supply, control.

3.2 Hydrogen storage cylinder

A device used to store high-pressure hydrogen on fuel cell electric vehicles.

3.3 Check valve

A valve used to prevent the backflow of gaseous media.

5.1 General requirements

5.1.1 All components of the on-board hydrogen system shall be checked and inspected before installation. The specifications and models of each component shall match and be complete.

5.1.2 The on-board hydrogen system shall be manufactured in accordance with the product drawings and other technical documents approved by the prescribed procedures. The hydrogenation port, hydrogen storage cylinder, valves and other components shall comply with relevant standards; a product certificate and batch inspection certificate shall be provided.

5.2 Safety protection requirements

5.2.1 In order to prevent the pressure downstream of the pressure regulator from abnormally increasing, the following two methods can be used.

5.3 Installation strength requirements

5.3.1 After the hydrogen storage cylinder (group) is installed and tightened, conduct a dynamic impact test according to the provisions of 7.2.2. It shall be ensured that the hydrogen storage cylinder (group) is still fixed on the fixed seat; the fastening parts shall not be deformed, broken, loosen, etc.

5.4 Air tightness requirements

5.4.1 The cylinder, valve, pipeline and each connection shall be well sealed. They shall be tested according to the test method in 7.3.

5.4.2 When using a gas detector to test air tightness, the hydrogen leakage rate at each detection point in each stage shall not be greater than 0.167 mL/min or the leakage concentration shall not be greater than 300 mL/m^3. See Appendix B for the calculation of leakage rate conversion between different gases.

5.5 Environmental adaptability requirements

5.5.1 The test pressure shall be the nominal working pressure of the on-board hydrogen system.

5.5.2 Environmental adaptability test includes high and low temperature test, damp heat test, vibration test, salt spray test. After each test, the air tightness of the system under the nominal working pressure shall be checked and meet the requirements of 5.4.2.

7.1 Test method of main shut-off valve

Connect the pipeline downstream of the main shut-off valve to the flow detection device, pressure detection device, stop valve (as shown in Figure 1). For multiple cylinder groups, each main shut-off valve shall be tested one by one. During the test, the non-test main shut-off valve is in a manual cut-off closed state.

7.2 Test method of installation strength

7.2.1 Test preparation

According to the product technical documents, fix the sample on the test bench. The fixing method shall not strengthen the fixation of the hydrogen storage cylinder (group).

Fill the hydrogen storage cylinder (group) with the test gas to the rated filling mass, OR use a test tooling with the cylinder mass plus the rated filling mass instead.

7.2.2 Dynamic test

Apply an acceleration impact to the test object. Maintain the acceleration value specified below for at least 30 ms. Conduct one test in each specified direction, for a total of 3 times.

7.2.3 Static test

The test method of static installation strength is as follows. […]

7.3 Test method of air tightness

7.3.1 Gas replacement

Gas sampling and analysis shall be carried out after replacement. The volume concentration of oxygen shall not exceed 0.5%.

7.3.2 Air tightness test

Test as follows.

7.4 Test method of environmental adaptability

7.4.1 High and low temperature test

7.4.1.1 Low temperature test

The test steps are as follows.

a) Place the system under test in a -40 °C test environment; let it stand for more than 12 hours;

b) The test environment temperature rises to 25 °C; the system under test is left standing at this temperature for more than 12 hours;

7.4.1.2 High temperature test

The test steps are as follows.

a) Place the system under test in a 60 °C test environment; let it stand for more than 12 hours;

b) The test environment temperature drops to 25 °C; the system under test is left standing at this temperature for more than 12 hours;

7.4.2 Damp heat test

The test is carried out in accordance with GB/T 2423.4. The variables are shown in Figure 5. The maximum temperature is 60 °C ± 3 °C, for a total of 5 cycles.

7.4.3 Vibration test

7.4.3.1 According to the installation position of the test object and the requirements of GB/T 2423.43, install the test object on the vibration bench. Random and fixed-frequency vibration loads are applied in each direction; the loading sequence should be random on the z-axis, fixed-frequency on the z-axis, random on the y-axis, fixed frequency on the y-axis, random on the x-axis, fixed frequency on the x-axis. The test process is in accordance with GB/T 2423.56.

7.4.3.4 During the test, if any abnormalities such as shedding, wear, or deformation occur, the test shall be stopped immediately.

7.4.4 Salt spray test

Conduct the test in accordance with the test conditions of GB/T 2423.17. The salt solution is prepared with sodium chloride and distilled or deionized water, which has a concentration of (5 ± 1)% (mass fraction). The pH value measured at 35 °C ± 2 °C is within 6.5 ~ 7.2. […]