add steam heater and condenser

[ElmiraShamlou]

Fixes/Resolves:

Adds a steam heater and condenser unit model, assuming full condensation at the outlet.
Estimate cooling water flow for the condenser option assuming specific design delta T.
Compatible with the WaterTap Property Packages.
Evaporative based desalinations like MD flowsheet, and crystallizer flowsheet will benefit from this added steam heater and condenser unit models. 

Changes proposed in this PR:

Legal Acknowledgement

By contributing to this software project, I agree to the following terms and conditions for my contribution:

1. I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[andrewlee94]

@ElmiraShamlou @adam-a-a I am guessing you aren't aware of this, but IDAES already has a model for a heat exchanger with a condensing section. In order to avoid duplication of code and effort, it would probably be good idea to check this out to see if it might meet your needs: https://github.com/IDAES/idaes-pse/blob/main/idaes/models_extra/power_generation/unit_models/feedwater_heater_0D.py

[ElmiraShamlou]

@ElmiraShamlou @adam-a-a I am guessing you aren't aware of this, but IDAES already has a model for a heat exchanger with a condensing section. In order to avoid duplication of code and effort, it would probably be good idea to check this out to see if it might meet your needs: https://github.com/IDAES/idaes-pse/blob/main/idaes/models_extra/power_generation/unit_models/feedwater_heater_0D.py

@andrewlee94 Thanks for the comment. Yes, I'm aware of the IDAES feed water heater. The current PR aims to enhance the steam heater's compatibility with the WaterTAP property packages. This is because the existing IDAES steam heater requires properties that are not available in WaterTAP property packages. We have previously discussed the possibility of integrating these properties to simplify future development efforts with the team.

[adam-a-a]

I am unsure whether the Mac failure is something we want to just dodge with requires_idaes_solver or if this is something that we deem fixable. It appears that something is going wrong with the report method with a NoneType where a path is expected. @bknueven I am guessing you'd recall

[ElmiraShamlou]

I am unsure whether the Mac failure is something we want to just dodge with requires_idaes_solver or if this is something that we deem fixable. It appears that something is going wrong with the report method with a NoneType where a path is expected. @bknueven I am guessing you'd recall

@adam-a-a I believe it's because of Chen's approximation

[bknueven]

I am unsure whether the Mac failure is something we want to just dodge with requires_idaes_solver or if this is something that we deem fixable. It appears that something is going wrong with the report method with a NoneType where a path is expected. @bknueven I am guessing you'd recall

The issue here is we call some external function not available without IDAES extensions. We should just use requires_idaes_solver.

@lbianchi-lbl we should probably consider updating the macOS tests given these external functions are now available for macOS, although that would require re-working the requires_idaes_solver handle to be a bit more subtle (really should be ipopt_has_HSL_solvers...

[ElmiraShamlou]

My main comment is that I'm not convinced about introducing a new unit model to replicate the 0D heat exchanger with additional saturation constraints. In my previous experience with power plant modeling, you could simply build a heat exchanger and impose additional performance constraints. As long as you have good initial values, the optimization should work fine. Please correct me if the steam heater model includes more than that.

@Morgan88888888 The primary reason for developing this unit model is to calculate the steam consumption rate (given complete condensation of the steam at the outlet) across various flowsheets and configurations in treatment systems like membrane distillation where the steam requirement significantly varies with design. Given that the hot inlet steam flow rate is variable, additional steps are added to the main heat exchanger's initialization method to improve initialization for this specific case. From my experience, initializing a steam heater in the treatment flowsheet without these additional steps was challenging. If you have experience using heat exchangers in similar applications without the need for modifications in initialization, sharing your experience could be greatly helpful.  Another consideration is that we plan to add flowsheets containing multiple steam heaters; having this unit prevents the need to replicate extra constraints for each one.

[bknueven]

Another consideration is that we plan to add flowsheets containing multiple steam heaters; having this unit prevents the need to replicate extra constraints for each one.

I strongly agree with this -- as soon as we have the same code in two different places a refactor with tests like this makes the most sense for maintainability and reliability.

[codecov]

Codecov Report

Attention: Patch coverage is 97.80220% with 2 lines in your changes missing coverage. Please review.

Project coverage is 93.65%. Comparing base (2c7f7d8) to head (6608eeb).
Report is 1 commits behind head on main.

Files	Patch %	Lines
watertap/costing/unit_models/heat_exchanger.py	80.00%	1 Missing ⚠️
watertap/unit_models/steam_heater_0D.py	98.83%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1358      +/-   ##
==========================================
+ Coverage   93.63%   93.65%   +0.01%     
==========================================
  Files         285      286       +1     
  Lines       30580    30670      +90     
==========================================
+ Hits        28635    28723      +88     
- Misses       1945     1947       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[MarcusHolly]

LGTM - just one comment that may or may not hold up this PR

[Morgan88888888]

Looks good to me! 👍 Thanks for your work on this.