GB/T 44262-2024Technical requirements for the sampling of hydrogen for proton exchange membrane fuel cell vehicles (English PDF)

4.1 Hydrogen Sampling Device

4.1.1 General requirements The hydrogen sampling device shall satisfy the following requirements:

---The design of the hydrogen sampling device shall comply with the relevant provisions of GB 50156, GB 50516 and GB/T 43674;

---Materials in contact with hydrogen in the hydrogen sampling device shall comply with the relevant provisions of GB/T 29279;

---The hydrogen sampling device shall not contaminate the sample, and the materials in contact with hydrogen in the sampling device shall not adsorb the collected components. The overall performance shall be subject to a quality assessment in accordance with GB/T 43306.

4.1.2 Basic composition The hydrogen sampling device should be equipped with sampling source port, stop valve, pressure gauge, pressure reducing valve, inlet valve, outlet valve, sampling gas cylinder, bypass valve, safety valve, check valve, venting component and grounding component. It is advisable to choose valves with a small dead volume. The schematic diagram of the hydrogen sampling device is shown in Figure 1. Hydrogen sampling devices with the same functions as shown in the Figure may also adopt this Figure. Each sample source port of the hydrogen sampling device shall be equipped with a separate stop valve, and the nominal pressure of the stop valve shall be greater than the maximum allowable working pressure of the sample source port.

4.1.3.3 Pressure gauge The pressure gauge shall comply with the provisions of GB/T 1226 or GB/T 1227. The measuring range of the sample source pressure gauge should be 1.5 ~

3.0 times the maximum allowable working pressure of the sample source port, and the measuring range of the output pressure gauge should be 1.5 ~

3.0 times the design sampling pressure.

4.1.3.4 Pressure reducing valve The pressure reducing valve shall comply with the provisions of GB/T 12244 and GB/T 43306. Its material should be stainless steel and subject to inert treatment, and the dead volume should be as small as possible. The nominal pressure shall be greater than the maximum allowable working pressure of the sample source port. The outlet pressure shall be adjustable to the design sampling pressure.

4.1.3.5 Inlet valve, outlet valve and bypass valve The inlet valve, outlet valve and bypass valve shall be valves that are easy to open and close (for example, ball valves), and the nominal pressure shall be greater than the set pressure of the safety valve.

4.1.3.6 Sampling gas cylinder The sampling gas cylinder shall comply with the relevant provisions of special equipment and be exclusively used. Its nominal working pressure shall not be lower than the maximum design sampling pressure. The sampling gas cylinder should be a double-valve type. For sampling gas cylinder used for adsorbent impurity detection, the inner wall, inlet valve and outlet valve of the gas cylinder shall be subject to the inert treatment.

4.1.3.7 Safety valve The safety valve should be a full-open safety valve, and the set pressure should be 1.05 ~

1.15 times the maximum design sampling pressure of the hydrogen sampling device.

4.1.3.8 Check valve The opening pressure of the check valve should be greater than 69 kPa.

6.3 System Blowing

6.3.1 General rules The system blowing shall be carried out in accordance with

6.3.2 or 6.3.3. When sampling the hydrogen refueling nozzle outlet, it shall be carried out in accordance with 6.3.2.

6.3.2 Continuous blowing displacement method The continuous blowing displacement method is carried out in accordance with the following steps:

a) When confirming that the stop valve A is closed, open the sample source hydrogen valve;

b) Slowly open the stop valve A and adjust the pressure reducing valve B to the sampling pressure;

c) Successively open the inlet valve D, sampling gas cylinder inlet valve E, sampling gas cylinder outlet valve F and outlet valve G to allow the blown hydrogen to flow through the sampling device and sampling gas cylinder. During operation, the pressure and temperature of the sampling gas cylinder shall be observed. When the gas cylinder pressure exceeds the sampling pressure or the gas cylinder temperature is significantly higher than the ambient temperature, the sample source hydrogen valve shall be immediately closed. The amount of gas blown shall be not less than 600 times the total volume of the sampling gas cylinder and the sampling device pipeline.

6.3.3 Inflate-vent displacement method The inflate-vent displacement method is carried out in accordance with the following steps:

a) Confirm that the stop valve A is closed and open the sample source hydrogen valve;

b) Slowly open the stop valve A and adjust the pressure reducing valve B to the sampling pressure;

c) Successively open the inlet valve D and sampling gas cylinder inlet valve E to allow hydrogen to flow into the sampling gas cylinder;

d) After the output pressure gauge is stable, close the inlet valve D, open the sampling gas cylinder outlet valve F and outlet valve G, vent the hydrogen in the sampling gas cylinder and pipeline, and close the outlet valve G;

e) Open the inlet valve D. After the output pressure gauge is stable, close the inlet valve D, open the outlet valve G, vent the hydrogen in the sampling gas cylinder and pipeline, and then, close the outlet valve G;

f) When the sampling pressure is less than or equal to 3 MPa, repeat step

e) for no less than 9 times; when the sampling pressure is greater than 3 MPa, repeat step

6.4 Sample Collection

6.4.1 After completing the system blowing in accordance with 6.3.2, follow the following steps to collect samples:

a) Close the sampling gas cylinder outlet valve F;

b) After the output pressure gauge is stable, close the sampling gas cylinder inlet valve E;

c) Close the sample source hydrogen valve and the stop valve A;

d) Open the bypass valve C to discharge the remaining hydrogen in the hydrogen sampling device;

e) Close the inlet valve D and outlet valve G, and remove the sampling gas cylinder;

f) Use a hydrogen leak detector to detect leaks in the removed sampling gas cylinder. During operation, the pressure and temperature of the sampling gas cylinder shall be observed. When the gas cylinder pressure exceeds the sampling pressure or the gas cylinder temperature is significantly higher than the ambient temperature, the sample source hydrogen valve shall be immediately closed.

6.4.2 After completing the system blowing in accordance with 6.3.3, follow the following steps to collect samples:

a) Open the inlet valve D;

b) After the output pressure gauge is stable, close the sampling gas cylinder outlet valve F and the sampling gas cylinder inlet valve E;

c) Close the sample source hydrogen valve and the stop valve A;