Successful level measurement in liquid hydrogen at -253 °C
Linde Engineering and Endress+Hauser develop a solution to meet the highest demands of hydrogen refueling
As an energy carrier, hydrogen is essential to sustainability and climate goals. LH₂ requires special tanks and level monitoring at -253 °C. Endress+Hauser and Linde Engineering developed the Liquicap FMI51 to meet these requirements. A stainless steel probe rod and a ceramic insulation feedthrough enable precise measurements despite extreme conditions. The fast response time (0.3s) and low installation effort make the solution ideal for the demanding storage and transportation of LH₂.
Requirements for continuous level measurement in LH2
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Extreme temperature resistance
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Suitable insulation in consideration of enormous (low) temperature changes
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International Ex approvals
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Very fast detection of filling level changes
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High reliability
"Filling the pump tank correctly is essential for controlled pump operation. The collaboration with Endress+Hauser was very goal-oriented right from the start"
Linde Engineering
The challenge
Liquid hydrogen (LH₂) has an extremely low boiling point of about -253 °C . This requires special tanks and transport containers, as well as level monitoring that can withstand these extreme conditions.
Our solution
Together with Linde Engineering, Endress+Hauser developed the capacitive probe Liquicap FMI51, which meets these huge requirements. A bare stainless steel (316Ti) is used as the probe rod. The liquid hydrogen serves as an insulator between the container and the probe. For space-related reasons in the cryogenic pump, a bypass is used as both a measuring vessel and mass tube.
Due to the low boiling point of hydrogen (-253 °C), a gas phase prevails in the area immediately in front of the process connection of the probe. This gas phase, in combination with the excellent properties of the ceramic insulation feedthrough, creates almost ambient temperatures at the process connection. The fast response time (0.3s) is ideal for this application.
Even in several years of operation, the measurement runs without failures.