Liquid Hydrogen Fuel Station

Good Day !

I am working on developing code for a Subcooled Liquid Hydrogen Fuel station using MATLAB & Simulink. Currently, I saw the code for a liquid-to-gas fuel station, but I require assistance to obtain the MATLAB code specifically for a Subcooled liquid-to-liquid hydrogen fuel station.

Any advice or assistance would be greatly appreciated.

Thank You

[Yifeng Tang]

Hi Shiva,

Are you familiar with Simscape? What you have in mind should be easier than Liquid-to-gas using Simscape, as no phase change needs to be modeled.

Answer 1

[Sam Chak]

Hi @Shiva Kumar Bairoju

Like @Yifeng Tang, I'd also suggest modeling this system using Simscape, as the entire hydrogen refueling station consists of many subsystems. If modeling in MATLAB, each subsystem may require hundreds of lines of code to accurately describe its mechanisms, including various equations and state control logic structures. I'm still learning how to use Simscape.

The graphical approach in Simscape typically bypasses these complexities, allowing the user to primarily specify the values of the parameters and the desired operating conditions of the system. You may refer to the following examples for ideas:

https://www.mathworks.com/help/hydro/ug/hydrogen-refueling-station.html

https://www.youtube.com/watch?v=xGvFLeea5p0

[Shiva Kumar Bairoju]

I sincerely appreciate the time you have taken.

@Yifeng Tang In response to your question, i would say I'm not particularly well-versed in Simscape, though I do have understanding of MATLAB code.

@Sam Chak " The graphical approach in Simscape typically bypasses these complexities" I believe this is entirely accurate.

I have reviewed the link you provided, along with the YouTube video, and I appreciate you sharing them. I had previously seen them, and while they are similar to the process I am exploring, there are some differences related to my specific issue. Currently, there are numerous hydrogen fuel stations operational, most of which utilize a compressed hydrogen storage system operating at pressures between 50 and 850 barg (725 to 12,300 psig) and temperatures ranging from -40 to -80°C (-40 to -176°F).

I am currently working on the Subcooled Liquid Hydrogen Fuel station, which features a Liquid Hydrogen pump capable of achieving a maximum mass flow rate of 400 kg/h and a maximum pressure of 2.0 MPa at a temperature of 23.9 K. Maintaining this temperature while minimizing heat losses presents a significant challenge.

I have attached the reference schematic drawing.

[Yifeng Tang]

Depending on whether you think phase change is expected to be important in your system, you may choose to use the Thermal Liquid (if phase change isn't expected) or Two-Phase Fluids (if phase change is expected) to model the LH2 network. I am leaning towards TL at this point, but you would know this better. Simscape Fluids should have most if not all components you showed in your diagram. It looks to me that what you have isn't that different from a regular liquid network (say coolant, water, oil, etc.), just at a low temperature and having different properties.

Suggestion on steps toward a model as you shown in the diagram:

(1) Complete Simscape Onramp.

(2) decide on whether you need thermal liquid or two phase. Get the fluid properties needed.

(3) read this documentation page and understand the framework of "test harness" for components. the other content on this page doesn't matter as much.

(4) gather a set of steady-state operation condition, or "design condition", including pressure, temperature, heat flow at various locations. Looks like you already have some of that in your diagram.

(5) build test harness models to parametrize key components, like pump, valve, long pipes. Don't try to build the full model.

(6) once you have finished (5), gradually assemble parametrized components into a model. Run the model as often as possible when adding components to your model. Add control if necessary. Identify issue early before the full model is assembled.

Be patient, good luck, happy modeling :D