Forward osmosis unit model and Trevi's system flowsheet

[Zhuoran29]

This PR integrates the forward osmosis (FO) model developed from the Trevi System's pilot project and includes the following features:

• A property package describing the proprietary draw solution properties used by Trevi
• An FO unit model and its associated test file
• An example flowsheet of building Trevi's FO configuration
• A cost model based upon the Trevi's system costing numbers
• Documentation of both the unit model and example flowsheet

[kurbansitterley]

@Zhuoran29 can you check the failing tests? Just updated the repo to use WaterTAP v 1.0 so could be related to that.

[kurbansitterley]

haven't reviewed all the content yet, but left a few comments to fix before then.

[Zhuoran29]

@Zhuoran29 can you check the failing tests? Just updated the repo to use WaterTAP v 1.0 so could be related to that.

@kurbansitterley , Sorry for the late response. Yes, I've been looking into it and it seemed to need some more efforts to solve the convergence issue (seems related to an expr_if-like expression, even when scaling factor and jacobian matrix both look good). I'll try to fix it asap.

[kurbansitterley]

@Zhuoran29 can you check the failing tests? Just updated the repo to use WaterTAP v 1.0 so could be related to that.

@kurbansitterley , Sorry for the late response. Yes, I've been looking into it and it seemed to need some more efforts to solve the convergence issue (seems related to an expr_if-like expression, even when scaling factor and jacobian matrix both look good). I'll try to fix it asap.

If it is related to the expr_if, you should do a totally fresh install of your environment. There was a compatibility issue with a previous version of Pyomo that has since been fixed. So I'd recommend checking if that solves your problem first before going too much further down the rabbit hole.

[kurbansitterley]

Overall I am very impressed with this huge PR and think it is in great shape. There are a few code things to address and comments I left.

[Zhuoran29]

@kurbansitterley , thanks for the constructive suggestions. I've modified some of them and responded to those that I didn't change. Please feel free to follow with further comments.

[kurbansitterley]

Great job @Zhuoran29