Submission for measure SWHC005 Water-Cooled Chiller

[simularis]

Pull Request (PR) Description

This pull request includes a measure setup for SWHC005 Water-Cooled Chiller. For this measure, we have made the following setup:

• Added the new parameter (wc_option) to allow switching water-cooled chiller object type from Chiller:Electric:ReformulatedEIR to Chiller:Electric:EIR (in chw.pxt)
• Added the new parameter (chiller_plr_curve) to support importing chillers from EPlus library. Initially, we do not propose linking this to chiller_model (in chw.pxt)
• Added chiller performance curves for the measure cases provided by Energy Solutions through personal communication, which stem from an effort with SCE to recommend new tiers in DEER2021/DEER2022 (in chw.pxt)
• Added chiller performance curves (compatible with Chiller:Electric:ReformulatedEIR) for the base cases selected from the set of performance curves in EPlus library (chiller.idf). (in chw.pxt)
• Introduced query file for collecting data for IPLV and chiller cooling capacity. (query_wcc.txt)
• Measure setup for chillers reflects distinct offerings varying by chiller type, capacity, and tier since code requirements vary by chiller type and capacity.

Why we need new performance curves and how we selected them

• Modeling the measure requires controlling both COP and IPLV. Although COP is a direct input to the model, IPLV is an output resulting from COP and performance curves.
• Energy Solutions previously supported an effort to recommend new tier definitions and as part of that effort modeled chillers with DEER2020 models. Measure case performance curves from that effort were provided & recommended to us.
• For the base case model, the prototype’s default performance curves do not yield an IPLV/COP ratio close to the base case defined in the measure. Using a workbook to implement the IPLV calculations, we tabulated the IPLV/COP ratio for chiller models provided by EPlus in a reference file. Then, we selected a model matching the chiller type with a preference for ReformulatedEIR object type and IPLV closest to the base case definition. During testing, we also rejected a chiller model for which simulation yielded unphysical results at part load.
• For one capacity range we also defined an intermediate case with base case COP and measure case performance curves, to help isolate savings contributions from each parameter during QC.

Why we need new parameters

• Initial performance curves we received were compatible with Chiller:Electric:EIR rather than prototypes’ default Chiller:Electric:ReformulatedEIR (although later we received a set of curves compatible with Reformulated chiller).
• EPlus allows several options in the input field “Electric Input to Cooling Output Ratio Function of Part Load Ratio Curve Type”, and we have performance curve from multiple sources that use different options.

Main contributor: @behzadsalimian
QC by @simularis
We consulted @wsjsxn regarding the measure case performance curves

PR Author

• Craft a succinct title that effectively encapsulates the essence of the pull request, providing a general overview of the proposed changes.
• Provide a concise description of the measure, bug, or feature. Submit one PR per measure.
• For a new measure, attach a workbook named DEER_EnergyPlus_Modelkit_Measure_list_working.xlsx, containing only rows used for post-processing the measure. (see measure folder)
• Add comments in the code when necessary to facilitate the review process.
• Add a comment before the added code, including the author's full name, company, and specifying if it's a bug fix, new measure, or feature.
• For a new feature or bug, demonstrate the impact on energy consumption for selected cases with justification using plots and descriptions. to follow
• For a new measure, add a summary table showing total energy consumption per simulated case. to follow

PR Reviewer

• Label the PR with at least one of the following: New Measure, Bug, or Feature.
• Conduct a thorough code review.
• If the branch is behind the main, merge the branch locally to check for potential conflicts.
• If a bug, locally reproduce it and compare energy consumptions before and after.
• Explore creative ways to stress-test the code.
• Locally check the error file and other outputs.

[simularis]

Savings for screw chiller remain questionable, so we are going to comment out the TechIDs corresponding to screw chillers. The definitions for those TechIDs will be visible in the cases files, but they should be replaced if there is a future revision to the screw chiller model setup.

[simularis]

I created new pull request #108 to reflect significant changes in 2025 and archive the original setup in this pull request. This pull request no longer needs to be reviewed.