Buildings.Fluid.HeatExchangers.ActiveBeams
Package with active beams
Information
This package contains models of active beams. See the User's Guide for more information.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
| User's Guide | |
| Active beam unit for cooling | |
| Active beam unit for heating and cooling | |
| Package with performance data | |
| Package with examples of active beam models | |
| Collection of validation models | |
| Base classes for active beam models |
Buildings.Fluid.HeatExchangers.ActiveBeams.Cooling
Active beam unit for cooling
Information
Model of an active beam, based on the EnergyPlus beam model AirTerminal:SingleDuct:ConstantVolume:FourPipeBeam.
This model operates only in cooling mode. For a model that operates in both heating and cooling mode, use Buildings.Fluid.HeatExchangers.ActiveBeams.CoolingAndHeating.
For a description of the equations, see the User's Guide.
Performance data are available from Buildings.Fluid.HeatExchangers.ActiveBeams.Data.
References
- DOE(2015) EnergyPlus documentation v8.4.0 - Engineering Reference.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package MediumWat | Modelica.Media.Interfaces.Pa... | Medium 1 in the component | |
| replaceable package MediumAir | Modelica.Media.Interfaces.Pa... | Medium 2 in the component | |
| Integer | nBeams | 1 | Number of beams in parallel |
| Nominal condition | |||
| Generic | perCoo | redeclare parameter Data.Gen... | Performance data for cooling |
| Assumptions | |||
| Boolean | allowFlowReversalWat | true | = true to allow flow reversal in water circuit, false restricts to design direction (port_a -> port_b) |
| Boolean | allowFlowReversalAir | true | = true to allow flow reversal in air circuit, false restricts to design direction (port_a -> port_b) |
| Dynamics | |||
| Nominal condition | |||
| Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> 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 |
| Flow resistance | |||
| Boolean | from_dpWat | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistanceWat | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaMWat | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Advanced | |||
| Boolean | homotopyInitialization | true | = true, use homotopy method |
| MassFlowRate | mWat_flow_small | 1E-4*abs(perCoo.mWat_flow_no... | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | mAir_flow_small | 1E-4*abs(perCoo.mAir_flow_no... | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Initialization | |||
| Cooling | |||
| AbsolutePressure | pWatCoo_start | MediumWat.p_default | Start value of pressure [Pa] |
| Temperature | TWatCoo_start | MediumWat.T_default | Start value of temperature [K] |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package MediumWat | Medium 1 in the component | |
| replaceable package MediumAir | Medium 2 in the component | |
| FluidPort_a | watCoo_a | Fluid connector watCoo_a (positive design flow direction is from watCoo_a to watCoo_b) |
| FluidPort_b | watCoo_b | Fluid connector watCoo_b (positive design flow direction is from watCoo_a to watCoo_b) |
| FluidPort_a | air_a | Fluid connector air_a (positive design flow direction is from air_a to air_b) |
| FluidPort_b | air_b | Fluid connector air_b (positive design flow direction is from air_a to air_b) |
| HeatPort_a | heaPor | Heat port, to be connected to room air |
Modelica definition
Buildings.Fluid.HeatExchangers.ActiveBeams.CoolingAndHeating
Active beam unit for heating and cooling
Information
This model is identical to Buildings.Fluid.HeatExchangers.ActiveBeams.Cooling, except that an additional water stream and convector is added to allow for heating in addition to cooling.
For a description of the equations, see the User's Guide.
Performance data are available from Buildings.Fluid.HeatExchangers.ActiveBeams.Data.
Extends from Buildings.Fluid.HeatExchangers.ActiveBeams.Cooling (Active beam unit for cooling).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package MediumWat | PartialMedium | Medium 1 in the component | |
| replaceable package MediumAir | PartialMedium | Medium 2 in the component | |
| Integer | nBeams | 1 | Number of beams in parallel |
| Nominal condition | |||
| Generic | perCoo | redeclare parameter Data.Gen... | Performance data for cooling |
| Generic | perHea | redeclare parameter Data.Gen... | Performance data for heating |
| Assumptions | |||
| Boolean | allowFlowReversalWat | true | = true to allow flow reversal in water circuit, false restricts to design direction (port_a -> port_b) |
| Boolean | allowFlowReversalAir | true | = true to allow flow reversal in air circuit, false restricts to design direction (port_a -> port_b) |
| Dynamics | |||
| Nominal condition | |||
| Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> 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 |
| Flow resistance | |||
| Boolean | from_dpWat | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistanceWat | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaMWat | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Advanced | |||
| Boolean | homotopyInitialization | true | = true, use homotopy method |
| MassFlowRate | mWat_flow_small | 1E-4*abs(perCoo.mWat_flow_no... | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | mAir_flow_small | 1E-4*abs(perCoo.mAir_flow_no... | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Initialization | |||
| Cooling | |||
| AbsolutePressure | pWatCoo_start | MediumWat.p_default | Start value of pressure [Pa] |
| Temperature | TWatCoo_start | MediumWat.T_default | Start value of temperature [K] |
| Heating | |||
| AbsolutePressure | pWatHea_start | pWatCoo_start | Start value of pressure [Pa] |
| Temperature | TWatHea_start | TWatCoo_start | Start value of temperature [K] |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | watCoo_a | Fluid connector watCoo_a (positive design flow direction is from watCoo_a to watCoo_b) |
| FluidPort_b | watCoo_b | Fluid connector watCoo_b (positive design flow direction is from watCoo_a to watCoo_b) |
| FluidPort_a | air_a | Fluid connector air_a (positive design flow direction is from air_a to air_b) |
| FluidPort_b | air_b | Fluid connector air_b (positive design flow direction is from air_a to air_b) |
| HeatPort_a | heaPor | Heat port, to be connected to room air |
| FluidPort_a | watHea_a | Fluid connector a (positive design flow direction is from watHea_a to watHea_b) |
| FluidPort_b | watHea_b | Fluid connector b (positive design flow direction is from watHea_a to watHea_b) |