modelValvesIsolation

Heat pump isolation valves

Information

This model represents the heat pump isolation valves. The isolation valves are modeled as two-way two-position valves, which can be located at the heat pump inlet and/or outlet depending on the settings of the parameters have_valHpInlIso and have_valHpOutIso. It is assumed that the heat pumps always provide heating hot water. Optionally, chilled water return and supply and the associated isolation valves can be modeled by setting the parameter have_chiWat to true.

Parameters

Type	Name	Default	Description
Buildings.Templates.Components.Types.Valve	typValHpInlIso	if have_valHpInlIso then Buildings.Templates.Components.Types.Valve.TwoWayTwoPosition else Buildings.Templates.Components.Types.Valve.None	Valve type at HP inlet
Buildings.Templates.Components.Types.Valve	typValHpOutIso	if have_valHpOutIso then Buildings.Templates.Components.Types.Valve.TwoWayTwoPosition else Buildings.Templates.Components.Types.Valve.None	Valve type at HP outlet
Buildings.Templates.Components.Types.Valve	typValPhpInlIso	if have_valPhpInlIso then Buildings.Templates.Components.Types.Valve.TwoWayTwoPosition else Buildings.Templates.Components.Types.Valve.None	Valve type at polyvalent HP inlet
Buildings.Templates.Components.Types.Valve	typValPhpOutIso	if have_valPhpOutIso then Buildings.Templates.Components.Types.Valve.TwoWayTwoPosition else Buildings.Templates.Components.Types.Valve.None	Valve type at polyvalent HP outlet
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpChiWatUni_nominal	if have_hp and have_php then cat(1, dpHeaWatUni_nominal[1:nHp].(mChiWatUni_flow_nominal[1:nHp]./mHeaWatUni_flow_nominal[1:nHp]).^2, dpChiWatPhp_nominal) elseif have_hp then dpHeaWatUni_nominal[1:nHp].(mChiWatUni_flow_nominal[1:nHp]./mHeaWatUni_flow_nominal[1:nHp]).^2 else dpChiWatPhp_nominal	Pressure drop at design CHW mass flow rate - Each unit
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpHeaWatVal_nominal	if have_hp and have_php then cat(1, dpValveHeaWat_nominal[1:nHp]((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)), dpValveHeaWat_nominal[nHp + 1:nHp + nPhp]((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0))) elseif have_hp then dpValveHeaWat_nominal[1:nHp]((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)) else dpValveHeaWat_nominal[nHp + 1:nHp + nPhp]((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0))	Total HW pressure drop for inlet and outlet valves
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpHeaWat_nominal	dpFixedHeaWat_nominal .+ dpHeaWatVal_nominal	Total HW pressure drop: fixed + valves
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpChiWatVal_nominal	if have_hp and have_php then cat(1, dpValveChiWat_nominal[1:nHp]((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)), dpValveChiWat_nominal[nHp + 1:nHp + nPhp]((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0))) elseif have_hp then dpValveChiWat_nominal[1:nHp]((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)) else dpValveChiWat_nominal[nHp + 1:nHp + nPhp]((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0))	Total CHW pressure drop for inlet and outlet valves
Buildings.Templates.Components.Data.Valve[nHp + nPhp]	datValHeaWatUniOutIso		Unit outlet HW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp + nPhp]	datValHeaWatUniInlIso		Unit inlet HW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp + nPhp]	datValChiWatUniOutIso		Unit outlet CHW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp + nPhp]	datValChiWatUniInlIso		Heat pump inlet CHW isolation valve parameters
Configuration
Boolean	have_chiWat	true	Set to true if the plant provides CHW
Boolean	have_hp	true	Set to true for plants with non-reversible or reversible heat pumps
Boolean	have_php	false	Set to true for plants with polyvalent heat pumps
Integer	nHp		Number of heat pumps (excluding polyvalent HPs)
Integer	nPhp	0	Number of polyvalent heat pumps
Boolean	have_valHpInlIso	false	Set to true for isolation valves at HP inlet
Boolean	have_valHpOutIso	false	Set to true for isolation valves at HP outlet
Boolean	have_valPhpInlIso	false	Set to true for isolation valves at polyvalent HP inlet
Boolean	have_valPhpOutIso	false	Set to true for isolation valves at polyvalent HP outlet
Boolean	have_pumChiWatDedHp	false	Set to true for HP with separate dedicated primary CHW pumps
Nominal condition
Modelica.Units.SI.MassFlowRate[nHp + nPhp]	mHeaWatUni_flow_nominal		HW mass flow rate - Each unit
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpHeaWatUni_nominal		Pressure drop at design HW mass flow rate - Each unit
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpBalHeaWatUni_nominal	fill(0, nHp + nPhp)	Balancing valve pressure drop at design HW mass flow rate - Each unit
Modelica.Units.SI.MassFlowRate[nHp + nPhp]	mChiWatUni_flow_nominal		CHW mass flow rate - Each unit
Modelica.Units.SI.PressureDifference[nPhp]	dpChiWatPhp_nominal		Pressure drop at design CHW mass flow rate - Each polyvalent HP
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpBalChiWatUni_nominal	fill(0, nHp + nPhp)	Balancing valve pressure drop at design CHW mass flow rate - Each unit
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpValveHeaWat_nominal	fill(Buildings.Templates.Data.Defaults.dpValIso, nHp + nPhp)	HW isolation valve pressure drop (identical for inlet and outlet valves)
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpFixedHeaWat_nominal	dpHeaWatUni_nominal + dpBalHeaWatUni_nominal	Fixed HW pressure drop: HP + balancing valve
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpValveChiWat_nominal	if have_chiWat then fill(Buildings.Templates.Data.Defaults.dpValIso, nHp + nPhp) else fill(0, nHp + nPhp)	Isolation valve CHW pressure drop (identical for inlet and outlet valves)
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpFixedChiWat_nominal	if have_chiWat then dpBalChiWatUni_nominal + dpChiWatUni_nominal else fill(0, nHp + nPhp)	Total fixed CHW pressure drop
Modelica.Units.SI.PressureDifference[nHp + nPhp]	dpChiWat_nominal	if have_chiWat then dpFixedChiWat_nominal .+ dpChiWatVal_nominal else fill(0, nHp + nPhp)	Total CHW pressure drop: fixed + valves
Dynamics › Conservation equations
Modelica.Fluid.Types.Dynamics	energyDynamics	Modelica.Fluid.Types.Dynamics.DynamicFreeInitial	Type of energy balance: dynamic (3 initialization options) or steady state
Dynamics › Nominal condition
Modelica.Units.SI.Time	tau	10	Time constant at nominal flow
Assumptions
Boolean	allowFlowReversal	true	Set to false to simplify equations, assuming, but not enforcing, no flow reversal
Dynamics › Time needed to open or close valve
Boolean	use_strokeTime	energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState	Set to true to continuously open and close valve
Modelica.Units.SI.Time	strokeTime	120	Time needed to open or close valve
Modelica.Blocks.Types.Init	init	Modelica.Blocks.Types.Init.InitialOutput	Type of initialization (no init/steady state/initial state/initial output)
Real	y_start	1	Initial position of actuator
Advanced
Boolean	from_dp	true	= true, use m_flow = f(dp) else dp = f(m_flow)
Boolean	linearized	false	= true, use linear relation between m_flow and dp for any flow rate

Connectors

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_b	port_bChiWat	CHW supply (to primary loop)
Modelica.Fluid.Interfaces.FluidPort_a	port_aChiWat	CHW return (from primary loop)
Modelica.Fluid.Interfaces.FluidPort_b	port_bHeaWat	HW supply (to primary loop)
Modelica.Fluid.Interfaces.FluidPort_a	port_aHeaWat	HW return (from primary loop)
Modelica.Fluid.Interfaces.FluidPorts_b[nHp]	ports_bChiHeaWatHp	CHW/HW return – HP entering
Modelica.Fluid.Interfaces.FluidPorts_a[nHp]	ports_aChiHeaWatHp	CHW/HW supply – HP leaving
Modelica.Fluid.Interfaces.FluidPorts_a[nHp]	ports_aHeaWatHp	HW supply – HP leaving
Modelica.Fluid.Interfaces.FluidPorts_a[nHp]	ports_aChiWatHp	CHW supply – HP leaving
Buildings.Templates.Plants.HeatPumps.Interfaces.Bus	bus	Plant control bus
Modelica.Fluid.Interfaces.FluidPorts_b[nPhp]	ports_bChiWatPhp	CHW return – Polyvalent heat pump entering
Modelica.Fluid.Interfaces.FluidPorts_b[nPhp]	ports_bHeaWatPhp	HW return – Polyvalent heat pump entering
Modelica.Fluid.Interfaces.FluidPorts_a[nPhp]	ports_aHeaWatPhp	HW supply – Polyvalent heat pump leaving
Modelica.Fluid.Interfaces.FluidPorts_a[nPhp]	ports_aChiWatPhp	CHW supply – Polyvalent heat pump leaving

Components

Type	Name	Description
Buildings.Templates.Components.Actuators.Valve[nHp + nPhp]	valHeaWatUniOutIso	Unit outlet HW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp + nPhp]	valChiWatUniOutIso	Unit outlet CHW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp + nPhp]	valHeaWatUniInlIso	Unit inlet HW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp + nPhp]	valChiWatUniInlIso	Unit inlet CHW isolation valve
Fluid.Delays.DelayFirstOrder	junHeaWatSup	Fluid volume at junction
Fluid.Delays.DelayFirstOrder	junChiWatSup	Fluid volume at junction
Fluid.Delays.DelayFirstOrder	junHeaWatRet	Fluid volume at junction
Fluid.Delays.DelayFirstOrder	junChiWatRet	Fluid volume at junction

Name	Description
Medium

Revisions

July 10, 2026, by Antoine Gautier:
Refactored for plants with polyvalent heat pumps.
This is for #4512.
May 7, 2025, by Antoine Gautier:
Refactored with fixed resistance in valve component.
This is for #4227.
March 29, 2024, by Antoine Gautier:
First implementation.