H2scan's HY-ALERTA Produktlinie umfasst sowohl tragbare als auch fest installierte Wasserstoff-Lecksuchgeräte. Das Unternehmen HY-OPTIMA Produktlinie besteht aus Echtzeit-Inline-Wasserstoffmessgeräten für die Gasprozessanalyse in industriellen Anwendungen. Alle H2scan-Geräte sind sowohl in eigensicherer als auch in explosionsgeschützter Ausführung erhältlich. Darüber hinaus können HY-OPTIMA-Analysatoren entweder als Einzelgeräte oder als komplette Analysensysteme gebaut werden.
Herausforderung: Ungenaue Wasserstoffüberwachung
H2scan’s hydrogen analyzers are used in a wide variety of industries, including gas manufacturing, chemical manufacturing, and electrolyzer monitoring among many others. Half of their business comes from the oil and gas industry, where H2scan analyzers monitor hydrogen in gas streams from desulfurization, reforming and hydrocracking. In the last of these, too much hydrogen in the exit stream reveals inefficiencies in the hydrocracking process, and too little hydrogen indicates a reduction of throughput and wasted catalytic material. Inaccuracies in hydrogen monitoring can therefore cost a refinery hundreds of thousands to millions of dollars.
H2scan analyzers typically operate very close to atmospheric pressure. Some time ago, the company received inquiries about some high-purity analyzers that were not reporting accurately in the field, despite passing calibration and inspection before shipping. H2scan sent engineers to customer installations, and they discovered that these gas analyzers were experiencing erratic pressure fluctuations due to changing barometric pressure.
Pressure fluctuations were causing inaccurate readings for these hydrogen analyzers because the number of molecules in a gas volume is proportional to the pressure of the gas. The higher the pressure, the greater number of gas molecules in the same space. At high concentrations of hydrogen, even a small change in barometric pressure could significantly change the number of hydrogen molecules present in the gas stream. Changes in reported hydrogen are directly proportional to pressure changes: a 1% change in pressure will cause a 1% change in reported hydrogen. Stable pressure or a compensated signal is critical, especially at high hydrogen concentrations.
Lösung: Kontrolle des absoluten Drucks
The solution to this problem was to maintain a constant pressure at the H2scan sensor, and this meant using absolute pressure control. Unlike gauge pressure control, which uses the current barometric pressure as the zero reference, absolute pressure control uses absolute vacuum as the zero reference. Controlling for absolute pressure eliminates atmospheric pressure fluctuations from the equation, resulting in repeatable pressure control and accurate hydrogen gas analysis.
On the recommendation of a colleague, H2scan came to Alicat for
Standard-Absolutdruckregler der PC-Serie um den Druck am H2scan-Sensorkopf aufrechtzuerhalten. Der für die Gegendruckregelung konfigurierte Alicat wurde stromabwärts des H2scan-Analysegeräts installiert, um einen konstanten Absolutdruck am Analysegerät aufrechtzuerhalten. Das Hochgeschwindigkeits-Proportional-Regelventil erreicht neue Durchflussraten in nur 50 ms, um sicherzustellen, dass der gewählte Absolutdruck aufrechterhalten wird.
Ergebnis: Stabile Wasserstoffanalysesysteme
When H2scan engineers added Alicats to their customer’s hydrogen analyzer systems, their analyzers performed as well as they did in the lab, no matter what the barometric pressure was in the field. H2scan now regularly specifies an Alicat back pressure controller to accompany their HY-OPTIMA analyzers when their customer is monitoring gas flows with higher concentrations of hydrogen. Because Alicat pressure controllers are available with NeSSI-compatible flow bodies and CSA Class 1 Division 2 (ATEX Zone 2) certification, H2scan also incorporates these units into HY-OPTIMA complete analyzer systems that are built on NeSSI substrates.
The native RS-232 communications of this “smart” pressure controller provides real-time setpoint control and feedback of the observed absolute pressure. H2scan also uses Alicat’s RS-232 for easy real-time recording of pressures during calibration of non-standard analyzers that operate at higher pressures or require higher accuracy. Alicat supports these easy-to-use electronic pressure controllers with a lifetime warranty and easy access to our expert team of applications engineers.
Wie geht es weiter mit H2scan?
Die nächste Generation von H2scan-Analysegeräten wird die Wasserstoffmesswerte automatisch und in Echtzeit an Druckänderungen am Eingang des Analysegeräts anpassen. Zu diesem Zweck benötigt das Analysegerät einen Druckmessumformer, der Echtzeitdaten an den nachgeschalteten elektronischen Druckregler zurückmelden kann.
Die PC-Serie von Alicat bietet diese Lösung in einem einzigen Gerät. Der Gegendruckregler ist dem H2scan-Analysegerät unmittelbar nachgeschaltet, und seine native RS-232-Kommunikation ermöglicht eine Echtzeitkommunikation mit dem H2scan-Analysegerät.
