In a high-pressure hydrogen system, during the pressure testing phase, what should be done if the nitrogen-based pressure test cannot reach the pressure required for hydrogen operation?
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In a high-pressure hydrogen system, during the pressure testing phase, what should be done if the nitrogen-based pressure test cannot reach the pressure required for hydrogen operation? The normal pressure of the hydrogenation system is 10 MPa, but the nitrogen pressure can reach at most 2 MPa. After the water pressure test, perform a 2 MPa nitrogen leak test, and then directly conduct a 10 MPa hydrogen leak test? How is security ensured?
In this case, since the nitrogen pressure can only reach 2 MPa and cannot attain the operating pressure of 10 MPa for hydrogen, you need to follow these steps to ensure safety: 1. After completing the hydrostatic test, conduct a airtightness test using nitrogen at 2 MPa to check for any obvious leaks in the system. 2. If the nitrogen gas leak test confirms no leaks, then it is possible to gradually switch to using inert gases with higher pressures (such as argon) for further testing, up to pressures close to or equal to those used for hydrogen, in order to assess the system’s sealing performance under high pressure. 3. Only after all the aforementioned airtightness tests have confirmed that the system is leak-free can hydrogen be slowly and gradually introduced up to 10 MPa, with strict monitoring of pressure changes and leakage. 4. Throughout the entire process, ensure that all safety valves and pressure relief devices are in proper working condition, so that measures can be taken immediately in the event of any abnormalities. 5. Remember, before and after performing any pressure testing and inflation operations, it is essential to ensure good ventilation inside the system as well as in the surrounding area, to prevent the accumulation of gas from posing a risk. The above procedures must be followed strictly in accordance with safety operating guidelines to ensure the safety of operators and the stable operation of the system. .
Take a look at the high-pressure bottled nitrogen option; it’s not very expensive
Buy a few more sets; they can be used in parallel
This post was last edited by hawkings on 2024-9-23 at 13:40. It is recommended to have a small nitrogen compressor available, as hydrogen leaks very easily; while it does not leak at low pressures, leaks do occur frequently at high pressures. Therefore, leak testing is extremely necessary. When using nitrogen cylinder sets, since the pressure in the nitrogen cylinders is around 12.5 MPa, which is quite close to the system pressure of 10 MPa, less and less gas becomes available as the filling process progresses; therefore, using nitrogen cylinder sets may not be economical. Some clients employ small nitrogen compressors specifically for pressure strength tests and leak tests. Furthermore, the product hydrogen produced by the hydrogen production unit will not reach 10 MPa; it needs to be pressurized using a hydrogen compressor before being sent for hydrogenation. Nitrogen can also be compressed using a hydrogen compressor to conduct airtightness tests, but the temperature rise when compressing nitrogen with such a compressor is higher, so it is recommended to consult the manufacturer of the hydrogen compressor.
A new hydrogen compressor can be used to pump nitrogen into the system to ensure airtightness, and contact the compressor manufacturer to replace the nitrogen valve
The airtight pressure of nitrogen is insufficient; first ensure that the oxygen content in the system is less than 0.2%, and then helium leak testing can be carried out.