One of the greatest issues in developing a sustainable hydrogen economy is the issue of infrastructure. As it stands today, many unique and novel technologies exist for producing hydrogen cheaply, efficiently, and effectively from a wide range of sources – natural gas, biogas straight from waste, gasification of organic substances, electrolysis for curtailment, bacterial production, and artificial photosynthesis to name a few. Technology has also been rapidly improving to efficiently utilize hydrogen as well. Today’s fuel cells power forklifts, backup energy requirements, busses, aircraft, and even cars with much higher efficiencies than conventional engines. Why then do we not have hydrogen power everywhere? There isn’t an effective, economic means of connecting the two developments.
How do we solve this problem? At least one of the solutions is to look at how we can improve hydrogen liquefaction cycle efficiency and cost. By reducing capital cost of installation and increasing reliability and efficiency, we can target both the cost of hydrogen liquefaction and the time to return our initial investment in the liquefier. Naturally, this is all great, but if we don’t have a technology that can deliver on these promises, then we’re no better off then before. Fortunately, we’ve identified a technology that promises to provide advantages in all of these areas – a vortex tube! Vortex tubes are solid-state (no moving parts), can operate a low pressures, inexpensive to manufacture, and above all, may be able to unlock the secrets of ortho-para conversion! Before we get into what must sound like magic – a history lesson.
Vortex Modeling – CFD
For more detailed and accurate modeling of thermofluid phenomena in vortex tubes, computational fluid dynamics (CFD) studies have been initiated. Two CFD solvers, COMSOL and ANSYS-FLUENT, were utilized. Figure 3 shows the streamline of gas flow inside the vortex tube and cold core flowing countering the annulus hot stream. Initial COMSOL models determined the software unfit for the vortex tube.
Figure 3 shows the streamline of gas flow inside the vortex tube and cold core flowing countering the annulus hot stream (not shown). COMSOL initial CFD models determined the software unfit for vortex tube.
We have been producing some results now after working through the summer of 2016. The Model currently being used is an Ansys Fluent model we are able to model this in 2D. Allowing quick turn around times on parametric Studies. Here are some highlights from the studies, the first comparing higher pressures to demonstrate phenomena at super critical operating conditions.
This is from the initial data points of a vortex tube operating with hydrogen, the uncertainty’s here are an initial estimation. We still have a full uncertainty analysis planned.