Inconsistent definition of the field: Minimum Part Load Ratio

[KWSL]

Issue overview

In reviewing the different chiller models, I noticed that there are three different descriptions of the way a chiller operates below a minimum part load ratio. In all cases, the field name is the same: Minimum Part Load Ratio. Having different definitions for the same field name is confusing to users.

Details

In other simulation tools, the below the minimum part load ratio, the chiller will cycle on and off to meet the load. In EnergyPlus, the following chiller models describe this behavior in the documentation:

	Chiller:Absorption
	Chiller:Electric:EIR
	Chiller:Electric:Reformulated:EIR
	ChillerHeater:Absorption:DirectFired
	ChillerHeater:Absorption:DoubleEffect
	HeatPump:PlantLoop:EIR:Cooling
	HeatPump:PlantLoop:EIR:Heating

There are also some chiller models that apply false loading below the minimum part load ratio. In ASHRAE 90.1-2022 Table G3.1 10.b exception, this is called the minimum unloading ratio. The following chiller models describe this behavior in the documentation:

	Chiller:Absorption:Indirect
	Chiller:Electric
	Chiller:EngineDriven
	Chiller:CombustionTurbine

For these chiller models, I request that this field name be changed to Minimum Unloading Ratio

In addition, there are a number of chiller models that don't describe the how the chiller behaves below the minimum part load ratio:

	HeatPump:AirToWater:FuelFired:Heating
	Generator:InternalCombustionEngine
	Generator:CombustionTurbine
	HeatPump:WaterToWater:ParameterEstimation:Cooling
	HeatPump:WaterToWater:ParameterEstimation:Heating
	HeatPump:AirToWater:FuelFired:Heating (and Cooling)

For these chiller models, I request that the documentation be clarified, and that if any of the chillers use unloading instead of cycling below the minimum part load ratio, that the field name be changed as above.

Checklist

Add to this list or remove from it as applicable. This is a simple templated set of guidelines.

• Defect file added (list location of defect file here)
• Ticket added to EnergyPlus Defect Complexity (Github Project)
• Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)