Buildings.Applications.BaseClasses.Equipment
Equipment models for systems in applications package
Information
Package with equipment models for Buildings.Applications.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 ElectricChillerParallel
|
Multiple identical electric chillers |
 FlowMachine_m
|
Identical m_flow controlled pumps |
| FlowMachine_y
|
Identical speed controlled flow machines |
 Validation
|
Collection of validation models |
Buildings.Applications.BaseClasses.Equipment.ElectricChillerParallel
Multiple identical electric chillers
Information
This model implements a chiller parallel with num identical chillers. For the chiller model please see
Buildings.Fluid.Chillers.ElectricEIR.
Note that although the chillers have identical nominal conditions, they can have different
performance curves specified in performance data per.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialParallelElectricEIR (Partial model for electric chiller parallel).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | 2 | Number of equipment |
| Generic | per[num] | redeclare parameter Building... | Performance data |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Real | l[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Two-way valve | |||
| Density | rhoStd[numVal] | {Medium1.density_pTX(101325,... | Inlet density for which valve coefficients are defined [kg/m3] |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | false | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 30 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | fill(1, numFil) | Initial value of output:0-closed, 1-fully opened |
| Nominal condition | |||
| Time | tau1 | 30 | Time constant at nominal flow in chillers [s] |
| Time | tau2 | 30 | Time constant at nominal flow in chillers [s] |
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Initialization | |||
| Medium 1 | |||
| AbsolutePressure | p1_start | Medium1.p_default | Start value of pressure [Pa] |
| Temperature | T1_start | Medium1.T_default | Start value of temperature [K] |
| MassFraction | X1_start[Medium1.nX] | Medium1.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C1_start[Medium1.nC] | fill(0, Medium1.nC) | Start value of trace substances |
| ExtraProperty | C1_nominal[Medium1.nC] | fill(1E-2, Medium1.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Medium 2 | |||
| AbsolutePressure | p2_start | Medium2.p_default | Start value of pressure [Pa] |
| Temperature | T2_start | Medium2.T_default | Start value of temperature [K] |
| MassFraction | X2_start[Medium2.nX] | Medium2.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C2_start[Medium2.nC] | fill(0, Medium2.nC) | Start value of trace substances |
| ExtraProperty | C2_nominal[Medium2.nC] | fill(1E-2, Medium2.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
| input RealInput | TSet | Set point for leaving water temperature [K] |
| output RealOutput | P[num] | Electric power consumed by chiller compressor [W] |
Modelica definition
model ElectricChillerParallel "Multiple identical electric chillers"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialParallelElectricEIR
(
redeclare final Buildings.Fluid.Chillers.ElectricEIR chi[num](
final per=per));
replaceable parameter Buildings.Fluid.Chillers.Data.ElectricEIR.Generic per[num]
"Performance data";
end ElectricChillerParallel;
Buildings.Applications.BaseClasses.Equipment.FlowMachine_m
Identical m_flow controlled pumps
Information
This model implements a parallel of identical pumps with m_flow being controlled.
The number can be specified by setting a value of num.
The shutoff valves are used to avoid circulating flow among pumps.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPumpParallel (Partial model for pump parallel).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | per[num] | redeclare parameter Building... | Record with performance data |
| Integer | num | 2 | The number of pumps |
| Real | threshold | 0.05 | Hysteresis threshold |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Pump | |||
| Boolean | addPowerToMedium | false | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Two-way valve | |||
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Advanced | |||
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Pressure | dpMax | 2*max(pum.per.pressure.dp) +... | Maximum pressure allowed to operate the model, if exceeded, the simulation stops with an error [Pa] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Density | rhoStd | Medium.density_pTX(101325, 2... | Inlet density for which valve coefficients are defined [kg/m3] |
| Dynamics | |||
| Pump | |||
| Time | tau | 1 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Boolean | use_inputFilter | true | = true, if speed is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimePump | 30 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yPump_start[num] | fill(0, num) | Initial value of pump signals |
| Valve | |||
| Time | riseTimeValve | riseTimePump | Rise time of the filter (time to become 99.6 % open) [s] |
| Real | yValve_start[num] | fill(1, num) | Initial value of valve signals |
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Flow resistance | |||
| Boolean | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| input RealInput | u[num] | Continuous input signal for the flow machine [1] |
| output RealOutput | P[num] | Electrical power consumed by the pumps [W] |
Modelica definition
model FlowMachine_m "Identical m_flow controlled pumps"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPumpParallel
(
redeclare final Buildings.Fluid.Movers.FlowControlled_m_flow pum(
each final m_flow_nominal = m_flow_nominal,
final m_flow_start=yPump_start*m_flow_nominal,
each final dpMax=dpMax),
rhoStd=Medium.density_pTX(101325, 273.15+4, Medium.X_default));
// Note: Below we set a huge value for dpMax. This is needed for Dymola 2023
// to run
// simulateModel("Buildings.Applications.DataCenters.ChillerCooled.Examples.IntegratedPrimarySecondaryEconomizer", stopTime=86400, method="Cvode", tolerance=1e-07, resultFile="IntegratedPrimarySecondaryEconomizer");
// on commit 3362be949be55b3c1e320faec8c8bac999f98ba4.
// It seems to be an issue of Dymola evaluating the assertion before convergence,
// because the result file does not show such large a pressure, and the model
// works fine with Optimica.
parameter Modelica.Units.SI.Pressure dpMax(
displayUnit="Pa")=2*max(pum.per.pressure.dp)+6E11
"Maximum pressure allowed to operate the model, if exceeded, the simulation stops with an error";
Modelica.Blocks.Math.Gain gaiM_flow[num](each final k=m_flow_nominal)
"Gain for mass flow rate";
equation
connect(swi.y, gaiM_flow.u);
connect(gaiM_flow.y, pum.m_flow_in);
end FlowMachine_m;
Buildings.Applications.BaseClasses.Equipment.FlowMachine_y
Identical speed controlled flow machines
Information
This model implements a parallel of identical pumps with speed being controlled.
The number can be specified by setting a value of num.
The shutoff valves are used to avoid circulating flow among pumps.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPumpParallel (Partial model for pump parallel).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | per[num] | redeclare parameter Building... | Record with performance data |
| Integer | num | 2 | The number of pumps |
| Real | threshold | 0.05 | Hysteresis threshold |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Pump | |||
| Boolean | addPowerToMedium | false | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Two-way valve | |||
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Advanced | |||
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Density | rhoStd | Medium.density_pTX(101325, 2... | Inlet density for which valve coefficients are defined [kg/m3] |
| Dynamics | |||
| Pump | |||
| Time | tau | 1 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Boolean | use_inputFilter | true | = true, if speed is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimePump | 30 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yPump_start[num] | fill(0, num) | Initial value of pump signals |
| Valve | |||
| Time | riseTimeValve | riseTimePump | Rise time of the filter (time to become 99.6 % open) [s] |
| Real | yValve_start[num] | fill(1, num) | Initial value of valve signals |
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Flow resistance | |||
| Boolean | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| input RealInput | u[num] | Continuous input signal for the flow machine [1] |
| output RealOutput | P[num] | Electrical power consumed by the pumps [W] |
Modelica definition
model FlowMachine_y "Identical speed controlled flow machines"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPumpParallel
(
redeclare final Buildings.Fluid.Movers.SpeedControlled_y pum(final y_start=yPump_start),
rhoStd=Medium.density_pTX(101325, 273.15+4, Medium.X_default));
equation
connect(swi.y, pum.y);
end FlowMachine_y;