Buildings.Templates.Plants.Controls.MinimumFlow
Package of sequences for minimum flow bypass valve
Information
This package contains control sequences for the HW or CHW minimum flow bypass valve.
Package Content
| Name | Description |
|---|---|
 Controller
|
Minimum flow bypass valve controller |
 ControllerHeatPumps
|
CHW and/or HW minimum flow bypass valve controller for heat pump plants |
 Setpoint
|
Minimum flow setpoint calculation |
 Validation
|
Collection of validation models |
Buildings.Templates.Plants.Controls.MinimumFlow.Controller
Minimum flow bypass valve controller
Information
The minimum flow bypass valve is modulated based on a reverse acting control loop to maintain the primary flow rate at setpoint. The setpoint is calculated as described in Buildings.Templates.Plants.Controls.MinimumFlow.Setpoint.
When using isolation valve command signals
(have_valInlIso=true or have_valOutIso=true):
When any valve is commanded open, the bypass valve control loop is enabled.
The valve is opened 100 % otherwise.
When enabled, the bypass valve loop shall be biased to start with the valve 100 % open.
Otherwise
(have_valInlIso=false and have_valOutIso=false):
When any primary pump is proven on, the bypass valve control loop is enabled.
The valve is opened 100 % otherwise.
When enabled, the bypass valve loop shall be biased to start with the valve 100 % open.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | use_val | Set to true to use isolation valve command to enable control loop – Any unit | |
| Boolean | use_valEqu[nEqu] | Set to true to use isolation valve command to enable control loop – Each unit | |
| Boolean | use_pumPriDed | Set to true to use dedicated primary pump status to enable control loop – Any unit | |
| Boolean | use_pumPriDedEqu[nEqu] | Set to true to use dedicated primary pump status to enable control loop – Each unit | |
| Integer | nEqu | 0 | Number of plant equipment |
| Real | V_flow_nominal[:] | Design flow rate – Each unit [m3/s] | |
| Real | V_flow_min[:] | Minimum flow rate – Each unit [m3/s] | |
| Real | k | 1 | Gain of controller |
| Time | Ti | 0.5 | Time constant of integrator block [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | VPri_flow | Primary volume flow rate [m3/s] |
| input BooleanInput | u1PumPri_actual[nEqu] | Dedicated primary pump status |
| input BooleanInput | u1ValIso[nEqu] | Isolation valve command |
| output RealOutput | y | Valve command [1] |
| input BooleanInput | u1Equ[nEqu] | Equipment enable command |
| output RealOutput | VPriSet_flow | Primary flow setpoint [m3/s] |
Modelica definition
block Controller
"Minimum flow bypass valve controller"
// use_val = Modelica.Math.BooleanVectors.anyTrue(use_valEqu) but not valid CDL.
parameter Boolean use_val
"Set to true to use isolation valve command to enable control loop – Any unit";
parameter Boolean use_valEqu[nEqu](start=fill(false, nEqu))
"Set to true to use isolation valve command to enable control loop – Each unit";
// use_pumPriDed = Modelica.Math.BooleanVectors.anyTrue(use_pumPriDedEqu) but not valid CDL.
parameter Boolean use_pumPriDed(start=false)
"Set to true to use dedicated primary pump status to enable control loop – Any unit";
parameter Boolean use_pumPriDedEqu[nEqu](start=fill(false, nEqu))
"Set to true to use dedicated primary pump status to enable control loop – Each unit";
parameter Integer nEqu(
final min=1)=0
"Number of plant equipment";
parameter Real V_flow_nominal[:](
each final unit="m3/s")
"Design flow rate – Each unit";
parameter Real V_flow_min[:](
each final unit="m3/s")
"Minimum flow rate – Each unit";
parameter Real k(
min=0)=1
"Gain of controller";
parameter Modelica.Units.SI.Time Ti(
min=Buildings.Controls.OBC.CDL.Constants.small)=0.5
"Time constant of integrator block";
Buildings.Controls.OBC.CDL.Interfaces.RealInput VPri_flow(
final unit="m3/s")
"Primary volume flow rate";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1PumPri_actual[nEqu]
if use_pumPriDed "Dedicated primary pump status";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1ValIso[nEqu] if use_val
"Isolation valve command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput y(
final unit="1")
"Valve command";
Buildings.Controls.OBC.Utilities.PIDWithEnable ctl(
final k=k,
final Ti=Ti,
final reverseActing=true,
y_reset=1,
y_neutral=1)
"PI controller";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1Equ[nEqu]
"Equipment enable command";
Setpoint setFloMin(
final V_flow_nominal=V_flow_nominal,
final V_flow_min=V_flow_min,
nEqu=nEqu)
"Calculate minimum flow setpoint";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput VPriSet_flow(
final unit="m3/s")
"Primary flow setpoint";
Buildings.Controls.OBC.CDL.Logical.And valIsoOpeAndPumPriDed[nEqu]
"Valve commanded open and dedicated primary pump proven on";
Buildings.Controls.OBC.CDL.Logical.Sources.Constant notUseVal[nEqu](final k={
not use_valEqu[i] for i in 1:nEqu})
"True if valve command not required";
Buildings.Controls.OBC.CDL.Logical.Or valIsoOpeOrNotUse[nEqu] if use_val
"Valve commanded open or valve signal not required";
Buildings.Controls.OBC.CDL.Logical.Sources.Constant notUsePumPriDed[nEqu](
final k={not use_pumPriDedEqu[i] for i in 1:nEqu})
"True if dedicated primary pump status not required";
Buildings.Controls.OBC.CDL.Logical.Or pumPriDedOrNotUse[nEqu] if
use_pumPriDed
"Dedicated primary pump proven on or pump signal not required";
Utilities.PlaceholderLogical phPumPriDedOrNotUse[nEqu](each final have_inp=
use_pumPriDed, each final u_internal=true) "Placeholder signal";
Utilities.PlaceholderLogical phValIsoOpeOrNotUse[nEqu](each final have_inp=
use_val, each final u_internal=true) "Placeholder signal";
Buildings.Controls.OBC.CDL.Logical.MultiOr anyValIsoOpeAndPumPriDed(final nin
=nEqu) "True if any isolation valve open and dedicated pump proven on";
equation
connect(VPri_flow, ctl.u_m);
connect(ctl.y, y);
connect(u1Equ, setFloMin.u1);
connect(setFloMin.VPriSet_flow, ctl.u_s);
connect(setFloMin.VPriSet_flow, VPriSet_flow);
connect(notUseVal.y, valIsoOpeOrNotUse.u1);
connect(u1ValIso, valIsoOpeOrNotUse.u2);
connect(notUsePumPriDed.y, pumPriDedOrNotUse.u1);
connect(u1PumPri_actual, pumPriDedOrNotUse.u2);
connect(pumPriDedOrNotUse.y, phPumPriDedOrNotUse.u);
connect(phPumPriDedOrNotUse.y, valIsoOpeAndPumPriDed.u2);
connect(valIsoOpeOrNotUse.y, phValIsoOpeOrNotUse.u);
connect(phValIsoOpeOrNotUse.y, valIsoOpeAndPumPriDed.u1);
connect(valIsoOpeAndPumPriDed.y, anyValIsoOpeAndPumPriDed.u);
connect(anyValIsoOpeAndPumPriDed.y, ctl.uEna);
end Controller;
Buildings.Templates.Plants.Controls.MinimumFlow.ControllerHeatPumps
CHW and/or HW minimum flow bypass valve controller for heat pump plants
Information
HW minimum flow
The HW minimum flow bypass valve is modulated based on a reverse acting control loop to maintain the primary HW flow rate at setpoint. The setpoint is calculated as described in Buildings.Templates.Plants.Controls.MinimumFlow.Setpoint using the number of units commanded on in heating mode at each stage.
When using isolation valve command signals
(have_valInlIso=true or have_valOutIso=true): When
any HW isolation valve is commanded open, the HW bypass valve control loop
is enabled. The valve is opened 100 % otherwise. When enabled,
the HW bypass valve loop shall be biased to start with the valve
100 % open.
Otherwise
(have_valInlIso=false and have_valOutIso=false):
- For heating and cooling plants with common dedicated CHW and HW pumps: When any primary pump is proven on and the associated heat pump is commanded in heating mode, the HW bypass valve control loop is enabled. The valve is opened 100 % otherwise. When enabled, the HW bypass valve loop shall be biased to start with the valve 100 % open.
- For any other plants: When any primary HW pump is proven on, the HW bypass valve control loop is enabled. The valve is opened 100 % otherwise. When enabled, the HW bypass valve loop shall be biased to start with the valve 100 % open.
CHW minimum flow
The CHW minimum flow bypass valve is modulated based on a reverse acting control loop to maintain the primary CHW flow rate at setpoint. The setpoint is calculated as described in Buildings.Templates.Plants.Controls.MinimumFlow.Setpoint using the number of units commanded on in cooling mode at each stage.
When using isolation valve command signals
(have_valInlIso=true or have_valOutIso=true): When
any CHW isolation valve is commanded open, the CHW bypass valve control loop
is enabled. The valve is opened 100 % otherwise. When enabled,
the CHW bypass valve loop shall be biased to start with the valve
100 % open.
Otherwise
(have_valInlIso=false and have_valOutIso=false):
- For heating and cooling plants with common dedicated CHW and HW pumps: When any primary pump is proven on and the associated heat pump is commanded in cooling mode, the CHW bypass valve control loop is enabled. The valve is opened 100 % otherwise. When enabled, the CHW bypass valve loop shall be biased to start with the valve 100 % open.
- For any other plants: When any primary CHW pump is proven on, the CHW bypass valve control loop is enabled. The valve is opened 100 % otherwise. When enabled, the CHW bypass valve loop shall be biased to start with the valve 100 % open.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | have_heaWat | Set to true for plants that provide HW | |
| Boolean | have_chiWat | Set to true for plants that provide CHW | |
| Boolean | have_pumPriHdr | Set to true for headered primary pumps, false for dedicated pumps | |
| Boolean | have_pumChiWatPriDedHp | Set to true for HP with separate dedicated primary pumps for CHW and HW circuits | |
| Integer | nHp | Number of 2-pipe heat pumps | |
| Integer | nPhp | Number of polyvalent heat pumps | |
| Boolean | have_valInlIso | Set to true if inlet isolation valves are present | |
| Boolean | have_valOutIso | Set to true if outlet isolation valves are present | |
| Real | VHeaWat_flow_nominal[nEqu] | Design HW flow rate – Each unit [m3/s] | |
| Real | VHeaWat_flow_min[nEqu] | Minimum HW flow rate – Each unit [m3/s] | |
| Real | VChiWat_flow_nominal[nEqu] | Design CHW flow rate – Each unit [m3/s] | |
| Real | VChiWat_flow_min[nEqu] | Minimum CHW flow rate – Each unit [m3/s] | |
| Real | k | 1 | Gain of controller |
| Time | Ti | 0.5 | Time constant of integrator block [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input BooleanInput | u1PumHeaWatPriDedHp_actual[nHp] | Primary HW pump status – HP dedicated pumps |
| input BooleanInput | u1PumHeaWatPriDedPhp_actual[nPhp] | Primary HW pump status – Polyvalent HP dedicated pumps |
| input RealInput | VChiWatPri_flow | Primary CHW volume flow rate [m3/s] |
| input RealInput | VHeaWatPri_flow | Primary HW volume flow rate [m3/s] |
| input BooleanInput | u1ValHeaWatInlIso[nEqu] | Inlet HW isolation valve command |
| input BooleanInput | u1ValHeaWatOutIso[nEqu] | Outlet HW isolation valve command |
| output RealOutput | yValHeaWatMinByp | HW minimum flow bypass valve command [1] |
| input BooleanInput | u1Hp[nHp] | HP enable command |
| output RealOutput | VHeaWatPriSet_flow | Primary HW flow setpoint [m3/s] |
| input BooleanInput | u1HeaHp[nHp] | HP heating mode command |
| input BooleanInput | u1ValChiWatInlIso[nEqu] | Inlet CHW isolation valve command |
| input BooleanInput | u1ValChiWatOutIso[nEqu] | Outlet CHW isolation valve command |
| output RealOutput | yValChiWatMinByp | CHW minimum flow bypass valve command [1] |
| output RealOutput | VChiWatPriSet_flow | Primary CHW flow setpoint [m3/s] |
| input BooleanInput | u1HeaPhp[nPhp] | Polyvalent HP heating mode command |
| input BooleanInput | u1CooPhp[nPhp] | Polyvalent HP cooling mode command |
| input BooleanInput | u1PumChiWatPriDedHp_actual[nHp] | Primary CHW pump status – HP dedicated pumps |
| input BooleanInput | u1PumChiWatPriDedPhp_actual[nPhp] | Primary CHW pump status – Polyvalent HP dedicated pumps |
Modelica definition
block ControllerHeatPumps
"CHW and/or HW minimum flow bypass valve controller for heat pump plants"
parameter Boolean have_heaWat
"Set to true for plants that provide HW";
parameter Boolean have_chiWat
"Set to true for plants that provide CHW";
parameter Boolean have_pumPriHdr
"Set to true for headered primary pumps, false for dedicated pumps";
parameter Boolean have_pumChiWatPriDedHp(start=false)
"Set to true for HP with separate dedicated primary pumps for CHW and HW circuits";
// Use isolation valve command if valves are present and for:
// - HP with dedicated pumps serving both CHW and HW loops
// - Headered primary pumps
final parameter Boolean use_valEqu[nEqu] = {(have_valInlIso or have_valOutIso)
and (not have_pumPriHdr and i <= nHp and not have_pumChiWatPriDedHp
or have_pumPriHdr) for i in 1:nEqu}
"Set to true to use isolation valve command to enable control loop – Each unit";
final parameter Boolean use_val = (have_valInlIso or have_valOutIso)
and (not have_pumPriHdr and nHp > 0 and not have_pumChiWatPriDedHp
or have_pumPriHdr)
"Set to true to use isolation valve command to enable control loop – Any unit";
// Use dedicated primary pump status for:
// - HP with dedicated pumps serving both CHW and HW loops
// (valve may be open when HP disabled for expansion/contraction of water)
// - HP with dedicated pumps, one per CHW and HW loop
// - PHP with dedicated pumps
// Resolves to any configuration with dedicated pumps.
final parameter Boolean use_pumPriDedEqu[nEqu] =
{not have_pumPriHdr for i in 1:nEqu}
"Set to true to use dedicated primary pump status to enable control loop – Each unit";
final parameter Boolean use_pumPriDed = not have_pumPriHdr
"Set to true to use dedicated primary pump status to enable control loop – Any unit";
parameter Integer nHp
"Number of 2-pipe heat pumps";
parameter Integer nPhp
"Number of polyvalent heat pumps";
final parameter Integer nEqu = nHp + nPhp
"Heating or cooling equipment count";
parameter Boolean have_valInlIso
"Set to true if inlet isolation valves are present";
parameter Boolean have_valOutIso
"Set to true if outlet isolation valves are present";
parameter Real VHeaWat_flow_nominal[nEqu](
start=fill(0, nEqu),
unit=fill("m3/s", nEqu))
"Design HW flow rate – Each unit";
parameter Real VHeaWat_flow_min[nEqu](
start=fill(0, nEqu),
unit=fill("m3/s", nEqu))
"Minimum HW flow rate – Each unit";
parameter Real VChiWat_flow_nominal[nEqu](
start=fill(0, nEqu),
unit=fill("m3/s", nEqu))
"Design CHW flow rate – Each unit";
parameter Real VChiWat_flow_min[nEqu](
start=fill(0, nEqu),
unit=fill("m3/s", nEqu))
"Minimum CHW flow rate – Each unit";
parameter Real k(min=0) = 1 "Gain of controller";
parameter Modelica.Units.SI.Time Ti(
min=Buildings.Controls.OBC.CDL.Constants.small) = 0.5
"Time constant of integrator block";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1PumHeaWatPriDedHp_actual[nHp]
if have_heaWat and nHp > 0 and not have_pumPriHdr
"Primary HW pump status – HP dedicated pumps";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1PumHeaWatPriDedPhp_actual[nPhp]
if have_heaWat and nPhp > 0 and not have_pumPriHdr
"Primary HW pump status – Polyvalent HP dedicated pumps";
Buildings.Controls.OBC.CDL.Interfaces.RealInput VChiWatPri_flow(
final unit="m3/s")
if have_chiWat
"Primary CHW volume flow rate";
Buildings.Controls.OBC.CDL.Interfaces.RealInput VHeaWatPri_flow(
final unit="m3/s")
if have_heaWat
"Primary HW volume flow rate";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1ValHeaWatInlIso[nEqu]
if have_heaWat and have_valInlIso
"Inlet HW isolation valve command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1ValHeaWatOutIso[nEqu]
if have_heaWat and have_valOutIso
"Outlet HW isolation valve command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput yValHeaWatMinByp(
final unit="1")
if have_heaWat
"HW minimum flow bypass valve command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1Hp[nHp]
if nHp > 0
"HP enable command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput VHeaWatPriSet_flow(
final unit="m3/s")
if have_heaWat
"Primary HW flow setpoint";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1HeaHp[nHp]
if have_heaWat and have_chiWat and nHp > 0
"HP heating mode command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1ValChiWatInlIso[nEqu]
if have_chiWat and have_valInlIso
"Inlet CHW isolation valve command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1ValChiWatOutIso[nEqu]
if have_chiWat and have_valOutIso
"Outlet CHW isolation valve command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput yValChiWatMinByp(
final unit="1")
if have_chiWat
"CHW minimum flow bypass valve command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput VChiWatPriSet_flow(
final unit="m3/s")
if have_chiWat
"Primary CHW flow setpoint";
Controller ctlFloMinHeaWat(
final use_val=use_val,
final use_valEqu=use_valEqu,
final use_pumPriDed=use_pumPriDed,
final use_pumPriDedEqu=use_pumPriDedEqu,
final V_flow_nominal=VHeaWat_flow_nominal,
final V_flow_min=VHeaWat_flow_min,
final k=k,
final Ti=Ti,
final nEqu=nEqu)
if have_heaWat
"HW minimum flow control";
Controller ctlFloMinChiWat(
final use_val=use_val,
final use_valEqu=use_valEqu,
final use_pumPriDed=use_pumPriDed,
final use_pumPriDedEqu=use_pumPriDedEqu,
final V_flow_nominal=VChiWat_flow_nominal,
final V_flow_min=VChiWat_flow_min,
final k=k,
final Ti=Ti,
final nEqu=nEqu)
if have_chiWat
"CHW minimum flow control";
Utilities.PlaceholderLogical phHeaCooHp[nHp](
each final have_inp=have_heaWat and have_chiWat,
each final have_inpPh=false,
each final u_internal=have_heaWat)
if nHp > 0
"Placeholder signal for single mode applications";
Buildings.Controls.OBC.CDL.Logical.Not u1CooHp[nHp]
if have_chiWat and nHp > 0
"True if HP in cooling mode";
Buildings.Controls.OBC.CDL.Logical.And onAndHeaHp[nHp]
if have_heaWat and nHp > 0
"True if HP commanded on in heating mode";
Buildings.Controls.OBC.CDL.Logical.And onAndCooHp[nHp]
if have_chiWat and nHp > 0
"True if HP commanded on in cooling mode";
Buildings.Controls.OBC.CDL.Logical.And pumDedOnAndCooHp[nHp]
if have_heaWat
and have_chiWat
and nHp > 0
and not have_pumPriHdr
and not have_pumChiWatPriDedHp
"Dedicated pump on and cooling mode – HP with common CHW and HW pumps";
Buildings.Controls.OBC.CDL.Logical.And pumDedOnAndHeaHp[nHp]
if have_heaWat
and have_chiWat
and nHp > 0
and not have_pumPriHdr
and not have_pumChiWatPriDedHp
"Dedicated pump on and HP in heating mode – HP with common CHW and HW pump";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1HeaPhp[nPhp]
if nPhp > 0
"Polyvalent HP heating mode command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1CooPhp[nPhp]
if nPhp > 0
"Polyvalent HP cooling mode command";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1PumChiWatPriDedHp_actual[nHp]
if have_chiWat and nHp > 0 and not have_pumPriHdr and have_pumChiWatPriDedHp
"Primary CHW pump status – HP dedicated pumps";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1PumChiWatPriDedPhp_actual[nPhp]
if have_chiWat and not have_pumPriHdr and nPhp > 0
"Primary CHW pump status – Polyvalent HP dedicated pumps";
Utilities.PlaceholderLogical phValHeaWatInlIso[nEqu](
each final have_inp=have_valInlIso,
each final have_inpPh=false,
each final u_internal=false)
if have_heaWat
"Placeholder signal";
Utilities.PlaceholderLogical phValHeaWatOutIso[nEqu](
each final have_inp=have_valOutIso,
each final have_inpPh=false,
each final u_internal=false)
if have_heaWat
"Placeholder signal";
Buildings.Controls.OBC.CDL.Logical.Or valHeaWatInlOrOutIso[nEqu]
if have_heaWat
"Inlet or outlet HW isolation valve commanded open";
Utilities.PlaceholderLogical phValChiWatInlIso[nEqu](
each final have_inp=have_valInlIso,
each final have_inpPh=false,
each final u_internal=false)
if have_chiWat
"Placeholder signal";
Utilities.PlaceholderLogical phValChiWatOutIso[nEqu](
each final have_inp=have_valOutIso,
each final have_inpPh=false,
each final u_internal=false)
if have_chiWat
"Placeholder signal";
Buildings.Controls.OBC.CDL.Logical.Or valChiWatInlOrOutIso[nEqu]
if have_chiWat
"Inlet or outlet CHW isolation valve commanded open";
Utilities.ConcatenateSelectLogical pumDedOnCoo(
final have_u1=nHp > 0,
final have_u2=nPhp > 0,
nin2=nPhp,
nin1=nHp)
if have_chiWat and not have_pumPriHdr
"Dedicated pump on and cooling mode";
Utilities.ConcatenateSelectLogical pumDedOnHeaHpPhp(
final have_u1=nHp > 0,
final have_u2=nPhp > 0,
nin2=nPhp,
nin1=nHp)
if have_heaWat and not have_pumPriHdr
"Dedicated pump on and heating mode";
Utilities.PlaceholderLogical pumDedOnAndHeaHp1[nHp](
each final have_inp=have_heaWat
and have_chiWat
and nHp > 0
and not have_pumPriHdr
and not have_pumChiWatPriDedHp,
each final have_inpPh=true)
if have_heaWat and not have_pumPriHdr and nHp > 0
"Dedicated pump on and heating mode – HP";
Utilities.PlaceholderLogical pumDedOnAndHeaHp2[nHp](
each final have_inp=have_heaWat
and have_chiWat
and nHp > 0
and not have_pumPriHdr
and not have_pumChiWatPriDedHp,
each final have_inpPh=true)
if have_chiWat and not have_pumPriHdr and nHp > 0
"Dedicated pump on and heating mode – HP";
Utilities.ConcatenateSelectLogical onAndHea(
final have_u1=nHp > 0,
final have_u2=nPhp > 0,
final nin2=nPhp,
final nin1=nHp)
if have_heaWat
"Heating mode enable";
Utilities.ConcatenateSelectLogical onAndCoo(
final have_u1=nHp > 0,
final have_u2=nPhp > 0,
final nin2=nPhp,
final nin1=nHp)
if have_chiWat
"Cooling mode enable";
equation
connect(ctlFloMinHeaWat.y, yValHeaWatMinByp);
connect(ctlFloMinHeaWat.VPriSet_flow, VHeaWatPriSet_flow);
connect(ctlFloMinChiWat.y, yValChiWatMinByp);
connect(ctlFloMinChiWat.VPriSet_flow, VChiWatPriSet_flow);
connect(u1HeaHp, phHeaCooHp.u);
connect(phHeaCooHp.y, u1CooHp.u);
connect(u1Hp, onAndHeaHp.u1);
connect(VChiWatPri_flow, ctlFloMinChiWat.VPri_flow);
connect(VHeaWatPri_flow, ctlFloMinHeaWat.VPri_flow);
connect(u1CooHp.y, onAndCooHp.u2);
connect(u1CooHp.y, pumDedOnAndCooHp.u1);
connect(phHeaCooHp.y, onAndHeaHp.u2);
connect(phHeaCooHp.y, pumDedOnAndHeaHp.u1);
connect(u1Hp, onAndCooHp.u1);
connect(u1ValHeaWatInlIso, phValHeaWatInlIso.u);
connect(u1ValHeaWatOutIso, phValHeaWatOutIso.u);
connect(phValHeaWatInlIso.y, valHeaWatInlOrOutIso.u1);
connect(phValHeaWatOutIso.y, valHeaWatInlOrOutIso.u2);
connect(valHeaWatInlOrOutIso.y, ctlFloMinHeaWat.u1ValIso);
connect(u1ValChiWatInlIso, phValChiWatInlIso.u);
connect(u1ValChiWatOutIso, phValChiWatOutIso.u);
connect(phValChiWatInlIso.y, valChiWatInlOrOutIso.u1);
connect(phValChiWatOutIso.y, valChiWatInlOrOutIso.u2);
connect(valChiWatInlOrOutIso.y, ctlFloMinChiWat.u1ValIso);
connect(u1PumChiWatPriDedPhp_actual, pumDedOnCoo.u2);
connect(pumDedOnCoo.y, ctlFloMinChiWat.u1PumPri_actual);
connect(u1PumHeaWatPriDedPhp_actual, pumDedOnHeaHpPhp.u2);
connect(u1PumHeaWatPriDedHp_actual, pumDedOnAndHeaHp.u2);
connect(u1PumHeaWatPriDedHp_actual, pumDedOnAndCooHp.u2);
connect(pumDedOnHeaHpPhp.y, ctlFloMinHeaWat.u1PumPri_actual);
connect(pumDedOnAndHeaHp.y, pumDedOnAndHeaHp1.u);
connect(u1PumHeaWatPriDedHp_actual, pumDedOnAndHeaHp1.uPh);
connect(pumDedOnAndHeaHp1.y, pumDedOnHeaHpPhp.u1);
connect(pumDedOnAndHeaHp2.y, pumDedOnCoo.u1);
connect(u1PumChiWatPriDedHp_actual, pumDedOnAndHeaHp2.uPh);
connect(pumDedOnAndCooHp.y, pumDedOnAndHeaHp2.u);
connect(onAndHeaHp.y, onAndHea.u1);
connect(u1HeaPhp, onAndHea.u2);
connect(onAndHea.y, ctlFloMinHeaWat.u1Equ);
connect(onAndCooHp.y, onAndCoo.u1);
connect(onAndCoo.y, ctlFloMinChiWat.u1Equ);
connect(u1CooPhp, onAndCoo.u2);
end ControllerHeatPumps;
Buildings.Templates.Plants.Controls.MinimumFlow.Setpoint
Minimum flow setpoint calculation
Information
The minimum flow setpoint is determined as follows, to provide minimum flow through all operating units.
- For the units commanded on in the stage, calculate the highest ratio of minimum flow rate to design flow rate.
- Calculate the minimum flow setpoint as the highest minimum flow ratio multiplied by the sum of the design flow rates for the operating equipment.
Details
For plants consisting of identical units, the minimum flow setpoint is the minimum flow of each unit multiplied by the number of units enabled in the stage.
If the units have different minimum flow to design flow ratios, just maintaining the sum of the minimum flows will not satisfy the equipment with the highest relative minimum flows. Note that this also requires that equipment be balanced to distribute flow proportional to their design flow.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | V_flow_nominal[:] | Design flow rate – Each unit [m3/s] | |
| Real | V_flow_min[:] | Minimum flow rate – Each unit [m3/s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input BooleanInput | u1[nEqu] | Equipment enable command |
| output RealOutput | VPriSet_flow | Primary flow setpoint [m3/s] |
Modelica definition
block Setpoint
"Minimum flow setpoint calculation"
parameter Integer nEqu(
final min=1)=0
"Number of plant equipment";
parameter Real V_flow_nominal[:](
each final unit="m3/s")
"Design flow rate – Each unit";
parameter Real V_flow_min[:](
each final unit="m3/s")
"Minimum flow rate – Each unit";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput u1[nEqu]
"Equipment enable command";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput VPriSet_flow(
final unit="m3/s")
"Primary flow setpoint";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant floMin[nEqu](
final k=V_flow_min)
"Minimum flow rate";
Buildings.Controls.OBC.CDL.Conversions.BooleanToReal booToRea[nEqu](
each final realTrue=1,
each final realFalse=0)
"Convert to real signal";
Buildings.Controls.OBC.CDL.Reals.Multiply floMinEna[nEqu]
"Minimum flow for enabled equipment";
Buildings.Controls.OBC.CDL.Reals.Divide ratFloMinEna[nEqu]
"Minimum flow ratio for enabled equipment";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant floDes[nEqu](
final k=V_flow_nominal)
"Design flow rate";
Buildings.Controls.OBC.CDL.Reals.MultiMax maxRatFloMinEna(
nin=nEqu)
"Maximum of minimum flow ratio for enabled equipment";
Buildings.Controls.OBC.CDL.Reals.Multiply floDesEqu[nEqu]
"Design flow for enabled equipment";
Buildings.Controls.OBC.CDL.Reals.MultiSum sumFloDesEna(
nin=nEqu)
"Sum of design flow for enabled equipment";
Buildings.Controls.OBC.CDL.Reals.Multiply floMinSet
"Minimum flow setpoint";
equation
connect(u1, booToRea.u);
connect(booToRea.y, floMinEna.u2);
connect(floMin.y, floMinEna.u1);
connect(floDes.y, ratFloMinEna.u2);
connect(floMinEna.y, ratFloMinEna.u1);
connect(ratFloMinEna.y, maxRatFloMinEna.u);
connect(booToRea.y, floDesEqu.u1);
connect(floDes.y, floDesEqu.u2);
connect(maxRatFloMinEna.y, floMinSet.u1);
connect(floMinSet.y, VPriSet_flow);
connect(floDesEqu.y, sumFloDesEna.u);
connect(sumFloDesEna.y, floMinSet.u2);
end Setpoint;