Issue1754 ATES model

[amaccarini]

The PR is about a simplified 1D aquifer thermal energy storage model. There are a couple of things that I cannot fully fix:

• When I add SingleWell as component, the default unit for pressure is bar. I think it should be Pa, but I am not sure how to fix this.
• Even though I selected true for the parameter about pressure curves, I still get the warning message.

[mwetter]

• How would one compute flow distribution if an ATES system has 3 wells? It looks to me like a flow resistance to the ground from well to well is missing.

[mwetter]

@amaccarini : I think the model is close to being finished.
I changed the model to set the flow resistance on one side to be the same as on the other side, which reduces the amount of equations, and leads to a 1x1 rather than a 2x2 nonlinear system of equations for the initialization.

I have one item I like to discuss, which we can do next week:

• I think using rMax in the computation of dpAquifer_nominal is not correct: rMax is used for the heat transfer domain, but the wells could be farther away than 2*rMax in which case the resistance should be larger.

[amaccarini]

@mwetter Following our discussion last week, I introduced a new parameter d which is the distance between wells. This parameter is used to compute the pressure losses (instead of rMax). The value of rMax is set to d/2 by default.

[mwetter]

@amaccarini : Should rMax <= d/2 be enforced with an assertion? I noted for example in Examples.CoolingOffice, that d=200 and rMax=500, which I think is not a meaningful configuration.

Also, I assume rMax is the same as r_{Aquifer} in the graphics of the Multiwell documentation. This should be consistent.

[amaccarini]

@mwetter: Yes, that sounds like a good idea. I added an assertion to verify that rMax <= d/2. I also updated the image by using the names of parameters rWB and rMax.