
Monday, 16th December 2024
Hydrogen fuel cells are an up and coming, clean and eco-friendly substitute to standard combustion methods. Achieving optimal efficiency in these systems is a must if this to be a viable and alternative source of energy for the future. Therefore, our efforts of pursuing precise control of gas flow and system pressures are essential.
In the article below, we explore the different sensing methods which can be used in hydrogen fuel cell research and how pressure and mass flow devices contribute to optimising these technologies. Let’s run through those different methods now:
By using the Alicat devices with high turndown ratios of up to 10 000:1 this allows the up scaling of the processes throughout development.
As an example, a 20 SLPM mass flow meter or controller from Alicat with a 10 000:1 turn down ratio would either allow the measurement or control of flow rates from 0.0002 - 20 SLPM. Put another way a 20 SLPM mass flow device can measure from as little as 2 SCCM up to 20 SLPM! (click here to see our range of Alicat mass flow meters).
Controlling the right ratios and distribution of oxidants and reactants across the gas diffusion layers in stacks is critical for preserving efficiency of the fuel cells.
Did you know for example that the same 20 SLPM Alicat mass flow meter has a typical sensor response time of less and 1 millisecond and a typical flow indication response time of less than 10 milliseconds!!
As the sensor is inherently fast to measure changes in pressure (and therefore flow) a 20 SLPM Alicat mass flow controller has a typical control response time from as little as 30 milliseconds.
For set processes involving low flow and high pressure, a mass flow controller with Coriolis Technology is ideal. This is because it has an accuracy specification of up to ±0.5% of reading or ±0.05% of full scale for gas, whichever is greater and flow repeatability of up to ±0.05% of reading or ±0.025% of full scale, whichever is greater. These capabilities make Coriolis controllers particularly suited for hydrogen fuel cell testing, where precision in managing gas flow under high-pressure conditions is critical.
For increased flow rates and lower pressures, A flow controller that uses Differential Pressure (DP) over a laminar flow stack can be used for monitoring both flow and pressure while controlling the mass flow or pressure, across a large range. Alicat differential pressure flow devices can measure and output the calculated mass flow rate and volumetric flow rate as well as outputting the gas line pressure and temperature.
Consistent and reliable back pressure must also be maintained, while facing extreme humidity, temperatures and moisture-rich environments, which are common within the electrolysis. Equilibar designed a multi-orifice BPR (back pressure regulator) which are ideal for maintaining optimal conditions within the hydrogen fuel cell system. Equilibar BPR’s that use Alicat dual valve PCD’s as pilot regulators can offer pressure control as low as 0.0005 mBarG. Additionally, we can provide stainless steel controllers and meters that deliver fast and precise flow/pressure readings, while remaining unaffected by moist gasses flowing through the devices.
Optimising hydrogen fuel cells requires careful attention to flow and pressure control, and the technologies discussed here explain cleaner and more efficient energy solutions. From high turndown ratio flow devices enabling scalability, to Coriolis controllers for precise measurements at varying pressures, each tool plays their role in fine-tuning fuel cell performance.
As we continue to innovate, we turn to the advanced technology offer from devices in the Alicat mass flow controller and Equilibar back pressure regulator range. By continuing with these innovative methods, researchers and engineers can contribute to a sustainable energy future driven by reliable and eco-friendly technologies. Let’s watch this space as to how far hydrogen fuel cells will take us!
If you have any questions please do get in touch on sales@pctflow.com or call us on 01953 609930.
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