Added answers to designing chlorination unit.

[philthestone]

Some updates for the chorination_unit.ipynb tutorial: Answers were added for the open questions (except Q10. I'll update this ASAP, but let's just assume some generic values there until I know more.) and some minor changes were added.

• Answers are labeled with A[x] according to the the Question Q[x].
• Little changes or additions made in parts 1 and 2 were added in green, just so it is easier to see which information was added when you go through the notebook to update the coding parts that required further information.
• In the contact zone there are two major remarks/questions:
  1. The user will have to choose a residual concentration C_res instead of a contact time. I've therefore changed this in the code.
  2. We first spoke about giving the user the option to choose a configuration of the contact zone ("serpentine tubing" or "cylindrical_tank"). We haven't set up the model for the cylindrical tank yet. I'd suggest we include that option at a later time. I would update those missing equations ASAP, so I think it makes sense to leave the already set up option in at the moment, (even if it can't actually be used until we added the process algorithms for that case). But you can kick it out completely if you prefer to have the code clean and working.
• Concerning the implicit equation to find C_0 at a given C_res seems to have two solutions (see image). The solver only finds one of them depending on the initial guess. I'll talk to Eva, if there should be two solutions indeed, or if the equation is faulty. But let's work with the one solution that is found by the solver for now. I've added a warning in case no solution can be found.
• For the storage tank, I think we also need to include some design algorithms according to the model. I've added some lines, however I am not sure if it's implemented correctly but wanted to get some training and get used to the module. So I've outcommented it. Feel free to replace them.
• Corrected typos if found any and changed '^' to '**'.

[codecov[bot]]

Codecov Report

Merging #68 (5be811d) into main (746de72) will not change coverage. The diff coverage is n/a.

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##             main      #68   +/-   ##
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  Coverage   72.10%   72.10%           
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  Files          78       78           
  Lines       11997    11997           
  Branches     1372     1372           
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  Hits         8651     8651           
  Misses       2978     2978           
  Partials      368      368           

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[yalinli2]

Thanks @philthestone for the contribution and notes, I've look at your notes and changes in detail in the next couple of days and make updates accordingly.

I'll keep this PR open until I finish the updates.