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.Data.Valve[nHp]	datValHeaWatHpOutIso		Heat pump outlet HW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp]	datValHeaWatHpInlIso		Heat pump inlet HW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp]	datValChiWatHpOutIso		Heat pump outlet CHW isolation valve parameters
Buildings.Templates.Components.Data.Valve[nHp]	datValChiWatHpInlIso		Heat pump inlet CHW isolation valve parameters
Configuration
Integer	nHp		Number of heat pumps
Boolean	have_chiWat		Set to true if the plant provides CHW
Boolean	have_valHpInlIso		Set to true for isolation valves at HP inlet
Boolean	have_valHpOutIso		Set to true for isolation valves at HP outlet
Boolean	have_pumChiWatPriDed		Set to true for plants with separate dedicated primary CHW pumps
Nominal condition
Modelica.Units.SI.MassFlowRate[nHp]	mHeaWatHp_flow_nominal		HW mass flow rate - Each heat pump
Modelica.Units.SI.PressureDifference[nHp]	dpHeaWatHp_nominal		Pressure drop at design HW mass flow rate - Each heat pump
Modelica.Units.SI.PressureDifference[nHp]	dpBalHeaWatHp_nominal	fill(0, nHp)	Balancing valve pressure drop at design HW mass flow rate - Each heat pump
Modelica.Units.SI.MassFlowRate[nHp]	mChiWatHp_flow_nominal		CHW mass flow rate - Each heat pump
Modelica.Units.SI.PressureDifference[nHp]	dpChiWatHp_nominal	dpHeaWatHp_nominal.*(mChiWatHp_flow_nominal./mHeaWatHp_flow_nominal).^2	Pressure drop at design CHW mass flow rate - Each heat pump
Modelica.Units.SI.PressureDifference[nHp]	dpBalChiWatHp_nominal	fill(0, nHp)	Balancing valve pressure drop at design CHW mass flow rate - Each heat pump
Modelica.Units.SI.PressureDifference[nHp]	dpValveHeaWat_nominal	fill(Buildings.Templates.Data.Defaults.dpValIso, nHp)	HW isolation valve pressure drop (identical for inlet and outlet valves)
Modelica.Units.SI.PressureDifference[nHp]	dpFixedHeaWat_nominal	dpHeaWatHp_nominal + dpBalHeaWatHp_nominal	Fixed HW pressure drop: HP + balancing valve
Modelica.Units.SI.PressureDifference[nHp]	dpHeaWat_nominal	dpFixedHeaWat_nominal + (if have_valHpOutIso then dpValveHeaWat_nominal else fill(0, nHp)) + (if have_valHpInlIso then dpValveHeaWat_nominal else fill(0, nHp))	Total HW pressure drop: fixed + valves
Modelica.Units.SI.PressureDifference[nHp]	dpValveChiWat_nominal	fill(Buildings.Templates.Data.Defaults.dpValIso, nHp)	Isolation valve CHW pressure drop (identical for inlet and outlet valves)
Modelica.Units.SI.PressureDifference[nHp]	dpFixedChiWat_nominal	if have_chiWat then dpBalChiWatHp_nominal + dpChiWatHp_nominal else fill(0, nHp)	Total fixed CHW pressure drop
Modelica.Units.SI.PressureDifference[nHp]	dpChiWat_nominal	if have_chiWat then dpFixedChiWat_nominal + (if have_valHpOutIso then dpValveChiWat_nominal else fill(0, nHp)) + (if have_valHpInlIso then dpValveChiWat_nominal else fill(0, nHp)) else fill(0, nHp)	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

Components

Type	Name	Description
Buildings.Templates.Components.Actuators.Valve[nHp]	valHeaWatHpOutIso	HP outlet HW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp]	valChiWatHpOutIso	HP outlet CHW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp]	valHeaWatHpInlIso	HP inlet HW isolation valve
Buildings.Templates.Components.Actuators.Valve[nHp]	valChiWatHpInlIso	HP 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

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.