modelSupply_QT
Extends from DisHeatLib.Supply.BaseClasses.BaseSupply, DisHeatLib.Supply.BaseClasses.ThermalElectricInterface.
Information
General
This supply unit is modelled as a perfect heater delivering a prescribed supply temperature. The mass flow is controlled by a PI-controller using a set point for heat generation. The unit is constraint by a maximum heat flow capacity.
Heat and power
The unit can be modelled as a simple heat and power unit using the characteristic powerCha. Electric power consumption/generation is then set according to the power values corresponding to current heat flow using table entries from the characteristic (and linearly interpolating). Electric power consumption of the pump is also considered. Since the pump is considered to be cooled by the fluid, a one to one conversion between heat added to the fluid and pumping power is considered.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| General › Ports | |||
| Integer | nPorts (from PartialTwoPortVector) | Number of ports | |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPortVector) | true | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Nominal condition | |||
| Modelica.SIunits.MassFlowRate | m_flow_nominal (from BaseSupply) | Q_flow_nominal/((TemSup_nominal - TemRet_nominal)*cp_default) | Nominal mass flow rate |
| Modelica.SIunits.Power | Q_flow_nominal (from BaseSupply) | Nominal heat flow rate | |
| Modelica.SIunits.Temperature | TemSup_nominal (from BaseSupply) | Nominal supply temperature | |
| Modelica.SIunits.Temperature | TemRet_nominal (from BaseSupply) | Nominal return temperature | |
| Modelica.SIunits.PressureDifference | dp_nominal | Nominal pressure difference of pump | |
| Advanced | |||
| Modelica.SIunits.MassFlowRate | m_flow_small (from BaseSupply) | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow |
| Electric power | |||
| Boolean | isElectric (from ThermalElectricInterface) | true | Unit has electric interface |
| DisHeatLib.Supply.BaseClasses.BasePowerCharacteristic | powerCha (from ThermalElectricInterface) | Characteristic for heat and power units | |
| Nominal parameters | |||
| Modelica.SIunits.Efficiency | pump_eff | 0.4 | Total efficiency of the pump |
| Supply temperature | |||
| Boolean | use_T_in | false | Get the supply temperature from the input connector, otherwise use nominal value |
| Heat supply | |||
| Boolean | use_Q_in | false | Get the heat supply from the input connector, otherwise use nominal value |
| Boolean | use_m_flow_limit | false | Limit mass flow to input signal |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPortVector) | Fluid connector a (positive design flow direction is from port_a to ports_b) | |
| Modelica.Fluid.Interfaces.FluidPorts_b[nPorts] | ports_b (from PartialTwoPortVector) | Fluid connectors b (positive design flow direction is from port_a to ports_b) | |
| Modelica.Blocks.Interfaces.RealOutput | P (from ThermalElectricInterface) | Active power consumption (positive)/generation(negative) | |
| Modelica.Blocks.Interfaces.RealInput | TSet | Connector of Real input signal | |
| Modelica.Blocks.Interfaces.RealInput | QSet | ||
| Modelica.Blocks.Interfaces.RealInput | m_flow_limit |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Sources.RealExpression | otherPowerUnits (from ThermalElectricInterface) | Reserved for other power units (e.g., pumps); negative is generation, positive is consumption | |
| IBPSA.Fluid.HeatExchangers.Heater_T | heater | ||
| IBPSA.Fluid.Movers.FlowControlled_m_flow | pump | ||
| Controls.Q_flow_control | q_flow_control |
Revisions
- Feburary 27, 2019, by Benedikt Leitner:
Implementation and added User's guide.