Leak testing bipolar plates: Ensuring quality in fuel cell technology
As the hydrogen economy grows, one essential factor for its success is the efficient operation of fuel cells and electrolysers. A vital part of this process is ensuring that bipolar plates—crucial components in these systems—are leak-free. In this article, we'll explain the importance of leak testing, how the process works, and why it matters for the future of hydrogen technology.
Why leak testing matters for bipolar plates
Leak testing is a critical step in the quality control process for manufacturers of fuel cells and electrolysers. It ensures that the bipolar plates, which help manage the flow of gases like hydrogen and oxygen, are entirely gas-tight. Even a tiny leak can lead to performance issues or safety concerns, so thorough testing is essential to guarantee reliability.
Who handles leak testing?
Leak testing is typically carried out by fuel cell manufacturers or specialised companies that produce bipolar plates. These companies play a central role in ensuring the reliability and safety of the components used in hydrogen systems.
The leak testing process
At first glance, leak testing may seem straightforward, but it is pretty complex. Thanks to its light and inert nature, the process generally uses helium as a tracer gas, which allows for highly sensitive leak detection.
How does it work?
First, the plates are placed into a vacuum chamber and then sealed tightly. A vacuum is created inside the chamber, which allows even the most minor leaks to be detected. Helium is then introduced into the system, and a mass spectrometer scans for any helium that might escape, indicating a leak.
Step-by-step breakdown
- Preparation: The bipolar plates are placed into the machine, creating a vacuum in the chamber.
- Helium background check: Before adding helium, the system checks for any traces already present to set a baseline.
- Helium introduction: A mixture of helium and air is introduced into the cooling circuit of the plates.
- Leak detection: The mass spectrometer measures the helium levels, identifying any leaks.
- Multiple checks: For a thorough inspection, the test is repeated across various circuits, including the oxygen and hydrogen sides.
Why use helium instead of hydrogen?
You might wonder why helium is used for testing instead of hydrogen, primarily because hydrogen fuel cells use hydrogen. The answer is simple: safety. hydrogen is highly flammable and poses a risk of explosion in a vacuum environment. Helium, conversely, is non-reactive and safe to use in these conditions, making it the preferred choice for leak detection and the detectable leak rate is much smaller with helium compared to hydrogen as well.
The cost of leak testing
While essential, leak testing isn't cheap. The equipment involved, such as vacuum pumps and mass spectrometers, requires a significant financial investment. Additionally, the ongoing use of helium adds to the operational costs. However, automation in testing processes is helping manufacturers reduce labour costs and improve overall efficiency. As well as helium recovery unit is helping to minimize the helium consumption.
What happens when a leak is found?
If a leak is detected, the system immediately notifies the operator. However, identifying the exact location of the leak can be tricky, especially when testing multiple plates at once. In such cases, the plates must be retested individually to pinpoint the problem. Once the faulty plate is identified, the manufacturer must repair or recycle it.
Looking ahead: The future of leak testing
As hydrogen technology continues to advance, so too will leak testing methods. Ongoing innovations aim to make the process faster, more efficient, and even more accurate, helping to support the growing demand for high-quality fuel cell components.
The bigger picture: Quality assurance in the hydrogen economy
Quality assurance through rigorous leak testing is vital for the reliability of fuel cells and electrolysers. As the hydrogen economy expands, maintaining these high standards will be crucial for gaining consumer trust and ensuring the long-term success of these technologies.
In summary
Leak testing for bipolar plates is crucial to ensuring fuel cells' and electrolysers' efficiency and safety. By using advanced technologies and meticulous processes, manufacturers can meet the high standards required in the hydrogen industry. As the field continues to evolve, so will the methods of leak detection, driving us closer to a sustainable future powered by hydrogen.
MVS is here to help
We have more than 30 years of experience designing, manufacturing, and servicing vacuum equipment for industrial use, providing tailored solutions for our partners. Our helium leak-detection systems are also perfectly capable of testing bipolar plates. With the help of our Helium Recovery Units (HRU), the test gas can be reused multiple times. This way, our partners could save up to 95% on helium costs. Also, by capturing, purifying, and reusing helium, you will cut costs and promote environmental sustainability.
