Buildings.Fluid.HeatExchangers.DXCoils.WaterCooled
Waterr-cooled DX package unit
Information
This package contains water-cooled DX coil models, including single-speed, multi-speed, and variable-speed DX coil models.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
Name | Description |
---|---|
MultiStage | Multi speed water-cooled DX coils |
SingleSpeed | Single speed water-cooled DX coils |
VariableSpeed | Variable speed water-cooled DX coils |
Data | Package with performance data for water-cooled DX coils |
Examples | Package with example of water-cooled DX cooling coil models |
Validation | Collection of validation models |
Buildings.Fluid.HeatExchangers.DXCoils.WaterCooled.MultiStage
Multi speed water-cooled DX coils
Information
This model can be used to simulate a water-cooled DX cooling coil with multiple operating stages. Depending on the used performance curves, each stage could be a different compressor speed, or a different mode of operation, such as with or without hot gas reheat.
See Buildings.Fluid.HeatExchangers.DXCoils.UsersGuide for an explanation of the model.
Extends from Buildings.Fluid.HeatExchangers.DXCoils.BaseClasses.PartialWaterCooledDXCoil (Base class for water-cooled DX coils).
Parameters
Type | Name | Default | Description |
---|---|---|---|
DXCoil | datCoi | redeclare Buildings.Fluid.He... | Performance data |
replaceable package MediumEva | PartialMedium | Medium for evaporator | |
replaceable package MediumCon | PartialMedium | Medium for condenser | |
Boolean | computeReevaporation | true | Set to true to compute reevaporation of water that accumulated on coil |
Nominal condition | |||
PressureDifference | dpEva_nominal | Pressure difference over evaporator at nominal flow rate [Pa] | |
PressureDifference | dpCon_nominal | Pressure difference over condenser at nominal flow rate [Pa] | |
Assumptions | |||
Boolean | allowFlowReversalEva | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for evaporator |
Boolean | allowFlowReversalCon | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for condenser |
Flow resistance | |||
Condenser | |||
Boolean | from_dpEva | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceEva | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMEva | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Evaporator | |||
Boolean | from_dpCon | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceCon | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMCon | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Dynamics | |||
Condenser | |||
Time | tauEva | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Evaporator | |||
Time | tauCon | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Equations | |||
Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
Initialization | |||
Medium 1 | |||
AbsolutePressure | pEva_start | MediumEva.p_default | Start value of pressure [Pa] |
Temperature | TEva_start | MediumEva.T_default | Start value of temperature [K] |
MassFraction | XEva_start[MediumEva.nX] | MediumEva.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CEva_start[MediumEva.nC] | fill(0, MediumEva.nC) | Start value of trace substances |
ExtraProperty | CEva_nominal[MediumEva.nC] | fill(1E-2, MediumEva.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Medium 2 | |||
AbsolutePressure | pCon_start | MediumCon.p_default | Start value of pressure [Pa] |
Temperature | TCon_start | MediumCon.T_default | Start value of temperature [K] |
MassFraction | XCon_start[MediumCon.nX] | MediumCon.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CCon_start[MediumCon.nC] | fill(0, MediumCon.nC) | Start value of trace substances |
ExtraProperty | CCon_nominal[MediumCon.nC] | fill(1E-2, MediumCon.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Advanced | |||
Diagnostics | |||
Boolean | show_T | false | = true, if actual temperature at port is computed |
Connectors
Type | Name | Description |
---|---|---|
output RealOutput | P | Electrical power consumed by the unit [W] |
output RealOutput | QEvaSen_flow | Sensible heat flow rate in evaporators [W] |
output RealOutput | QEvaLat_flow | Latent heat flow rate in evaporators [W] |
FluidPort_a | port_a | Fluid connector for evaporator inlet (positive design flow direction is from port_a1 to port_b1) |
FluidPort_b | port_b | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
FluidPort_a | portCon_a | Fluid connector a of condenser (positive design flow direction is from port_a2 to port_b2) |
FluidPort_b | portCon_b | Fluid connector b of condenser (positive design flow direction is from port_a2 to port_b2) |
input IntegerInput | stage | Stage of cooling coil (0: off, 1: first stage, 2: second stage...) |
Modelica definition
Buildings.Fluid.HeatExchangers.DXCoils.WaterCooled.SingleSpeed
Single speed water-cooled DX coils
Information
This model can be used to simulate a water-cooled DX cooling coil with single speed compressor.
See Buildings.Fluid.HeatExchangers.DXCoils.UsersGuide for an explanation of the model.
Extends from Buildings.Fluid.HeatExchangers.DXCoils.BaseClasses.PartialWaterCooledDXCoil (Base class for water-cooled DX coils).
Parameters
Type | Name | Default | Description |
---|---|---|---|
DXCoil | datCoi | redeclare Buildings.Fluid.He... | Performance data |
replaceable package MediumEva | PartialMedium | Medium for evaporator | |
replaceable package MediumCon | PartialMedium | Medium for condenser | |
Boolean | computeReevaporation | true | Set to true to compute reevaporation of water that accumulated on coil |
Nominal condition | |||
PressureDifference | dpEva_nominal | Pressure difference over evaporator at nominal flow rate [Pa] | |
PressureDifference | dpCon_nominal | Pressure difference over condenser at nominal flow rate [Pa] | |
Assumptions | |||
Boolean | allowFlowReversalEva | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for evaporator |
Boolean | allowFlowReversalCon | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for condenser |
Flow resistance | |||
Condenser | |||
Boolean | from_dpEva | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceEva | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMEva | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Evaporator | |||
Boolean | from_dpCon | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceCon | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMCon | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Dynamics | |||
Condenser | |||
Time | tauEva | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Evaporator | |||
Time | tauCon | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Equations | |||
Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
Initialization | |||
Medium 1 | |||
AbsolutePressure | pEva_start | MediumEva.p_default | Start value of pressure [Pa] |
Temperature | TEva_start | MediumEva.T_default | Start value of temperature [K] |
MassFraction | XEva_start[MediumEva.nX] | MediumEva.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CEva_start[MediumEva.nC] | fill(0, MediumEva.nC) | Start value of trace substances |
ExtraProperty | CEva_nominal[MediumEva.nC] | fill(1E-2, MediumEva.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Medium 2 | |||
AbsolutePressure | pCon_start | MediumCon.p_default | Start value of pressure [Pa] |
Temperature | TCon_start | MediumCon.T_default | Start value of temperature [K] |
MassFraction | XCon_start[MediumCon.nX] | MediumCon.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CCon_start[MediumCon.nC] | fill(0, MediumCon.nC) | Start value of trace substances |
ExtraProperty | CCon_nominal[MediumCon.nC] | fill(1E-2, MediumCon.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Advanced | |||
Diagnostics | |||
Boolean | show_T | false | = true, if actual temperature at port is computed |
Connectors
Type | Name | Description |
---|---|---|
output RealOutput | P | Electrical power consumed by the unit [W] |
output RealOutput | QEvaSen_flow | Sensible heat flow rate in evaporators [W] |
output RealOutput | QEvaLat_flow | Latent heat flow rate in evaporators [W] |
FluidPort_a | port_a | Fluid connector for evaporator inlet (positive design flow direction is from port_a1 to port_b1) |
FluidPort_b | port_b | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
FluidPort_a | portCon_a | Fluid connector a of condenser (positive design flow direction is from port_a2 to port_b2) |
FluidPort_b | portCon_b | Fluid connector b of condenser (positive design flow direction is from port_a2 to port_b2) |
input BooleanInput | on | Set to true to enable compressor, or false to disable compressor |
Modelica definition
Buildings.Fluid.HeatExchangers.DXCoils.WaterCooled.VariableSpeed
Variable speed water-cooled DX coils
Information
This model can be used to simulate a water-cooled DX cooling coil with variable speed compressor.
See Buildings.Fluid.HeatExchangers.DXCoils.UsersGuide for an explanation of the model.
Extends from Buildings.Fluid.HeatExchangers.DXCoils.BaseClasses.PartialWaterCooledDXCoil (Base class for water-cooled DX coils).
Parameters
Type | Name | Default | Description |
---|---|---|---|
DXCoil | datCoi | redeclare Buildings.Fluid.He... | Performance data |
replaceable package MediumEva | PartialMedium | Medium for evaporator | |
replaceable package MediumCon | PartialMedium | Medium for condenser | |
Boolean | computeReevaporation | true | Set to true to compute reevaporation of water that accumulated on coil |
Real | minSpeRat | minSpeRat(min=0, max=1) | Minimum speed ratio |
Real | speRatDeaBan | 0.05 | Deadband for minimum speed ratio |
Nominal condition | |||
PressureDifference | dpEva_nominal | Pressure difference over evaporator at nominal flow rate [Pa] | |
PressureDifference | dpCon_nominal | Pressure difference over condenser at nominal flow rate [Pa] | |
Assumptions | |||
Boolean | allowFlowReversalEva | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for evaporator |
Boolean | allowFlowReversalCon | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for condenser |
Flow resistance | |||
Condenser | |||
Boolean | from_dpEva | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceEva | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMEva | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Evaporator | |||
Boolean | from_dpCon | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistanceCon | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaMCon | 0.1 | Fraction of nominal flow rate where flow transitions to laminar [1] |
Dynamics | |||
Condenser | |||
Time | tauEva | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Evaporator | |||
Time | tauCon | 60 | Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState) [s] |
Equations | |||
Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
Initialization | |||
Medium 1 | |||
AbsolutePressure | pEva_start | MediumEva.p_default | Start value of pressure [Pa] |
Temperature | TEva_start | MediumEva.T_default | Start value of temperature [K] |
MassFraction | XEva_start[MediumEva.nX] | MediumEva.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CEva_start[MediumEva.nC] | fill(0, MediumEva.nC) | Start value of trace substances |
ExtraProperty | CEva_nominal[MediumEva.nC] | fill(1E-2, MediumEva.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Medium 2 | |||
AbsolutePressure | pCon_start | MediumCon.p_default | Start value of pressure [Pa] |
Temperature | TCon_start | MediumCon.T_default | Start value of temperature [K] |
MassFraction | XCon_start[MediumCon.nX] | MediumCon.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | CCon_start[MediumCon.nC] | fill(0, MediumCon.nC) | Start value of trace substances |
ExtraProperty | CCon_nominal[MediumCon.nC] | fill(1E-2, MediumCon.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Advanced | |||
Diagnostics | |||
Boolean | show_T | false | = true, if actual temperature at port is computed |
Connectors
Type | Name | Description |
---|---|---|
output RealOutput | P | Electrical power consumed by the unit [W] |
output RealOutput | QEvaSen_flow | Sensible heat flow rate in evaporators [W] |
output RealOutput | QEvaLat_flow | Latent heat flow rate in evaporators [W] |
FluidPort_a | port_a | Fluid connector for evaporator inlet (positive design flow direction is from port_a1 to port_b1) |
FluidPort_b | port_b | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
FluidPort_a | portCon_a | Fluid connector a of condenser (positive design flow direction is from port_a2 to port_b2) |
FluidPort_b | portCon_b | Fluid connector b of condenser (positive design flow direction is from port_a2 to port_b2) |
input RealInput | speRat | Speed ratio |