Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples
Example models for rear door heat exchangers
Information
Package with example models for rear door heat exchangers.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Package Content
| Name | Description |
|---|---|
 Active
|
Example model for an active rear door heat exchanger |
| Passive
|
Example model for a passive rear door heat exchanger |
 BaseClasses
|
Base classes for rear door heat exchanger example models |
Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.Active
Example model for an active rear door heat exchanger
Information
Example model for an active rear door heat exchanger.
The model uses a constant water mass flow rate. The air mass flow rate is determined by the fan control. Because the IT load and the water mass flow rate are constant, the air mass flow rate is also constant after the initial transient.
Extends from Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.BaseClasses.PartialExample (Partial example model for a rear door heat exchanger).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| HeatFlowRate | Q_flow_nominal | -10000 | Nominal cooling duty (negative = heat removed from air) [W] |
| Temperature | TAirIn_nominal | 273.15 + 40 | Nominal air inlet temperature (warm server exhaust) [K] |
| Temperature | TAirOut_nominal | 273.15 + 30 | Nominal air outlet temperature of rear door heat exchanger [K] |
| Temperature | TCooIn_nominal | 273.15 + 20 | Nominal coolant inlet temperature [K] |
| Temperature | TCooOut_nominal | 273.15 + 30 | Nominal coolant outlet temperature [K] |
| MassFlowRate | mAir_flow_nominal | Q_flow_nominal/(TAirOut_nomi... | Nominal air mass flow rate [kg/s] |
| MassFlowRate | mCoo_flow_nominal | -Q_flow_nominal/(TCooOut_nom... | Nominal coolant mass flow rate [kg/s] |
| Power | PIT_nominal | 10000 | Nominal IT load power handled by rear door heat exchanger [W] |
| Generic | dat | dat(mAir_flow_nominal=mAir_f... | Performance data |
Modelica definition
model Active
"Example model for an active rear door heat exchanger"
extends Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.BaseClasses.PartialExample;
parameter Modelica.Units.SI.Power PIT_nominal = 10000
"Nominal IT load power handled by rear door heat exchanger";
parameter Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Data.Active.Generic
dat(
mAir_flow_nominal=mAir_flow_nominal,
mCoo_flow_nominal=mCoo_flow_nominal,
Q_flow_nominal=-PIT_nominal,
TAirIn_nominal=TAirIn_nominal,
TCooIn_nominal=TCooIn_nominal,
cpAir_nominal=cpAir_default,
cpCoo_nominal=cpCoo_default)
"Performance data";
Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Active hex(
redeclare package MediumCoo = MediumCoo,
redeclare package MediumAir = MediumAir,
dat = dat)
"Active rear door heat exchanger";
Sources.Boundary_pT airSou(
redeclare package Medium = MediumAir,
p=MediumAir.p_default + dat.dpAir_nominal,
nPorts=1,
T=TAirIn_nominal)
"Air source at nominal conditions";
FixedResistances.PressureDrop res(
redeclare package Medium = MediumAir,
m_flow_nominal=dat.mAir_flow_nominal,
dp_nominal=dat.dpAir_nominal) "Resistance of upstream rack";
equation
connect(senTAirIn.port_b, hex.portAir_a);
connect(hex.portAir_b, senTAirOut.port_a);
connect(senTCooIn.port_b, hex.portCoo_a);
connect(hex.portCoo_b, senTCooOut.port_a);
connect(airSou.ports[1], res.port_a);
connect(res.port_b, senTAirIn.port_a);
end Active;
Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.Passive
Example model for a passive rear door heat exchanger
Information
Example model for a passive rear door heat exchanger.
The model uses a constant air and water mass flow rate.
Extends from Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.BaseClasses.PartialExample (Partial example model for a rear door heat exchanger).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| HeatFlowRate | Q_flow_nominal | -10000 | Nominal cooling duty (negative = heat removed from air) [W] |
| Temperature | TAirIn_nominal | 273.15 + 40 | Nominal air inlet temperature (warm server exhaust) [K] |
| Temperature | TAirOut_nominal | 273.15 + 30 | Nominal air outlet temperature of rear door heat exchanger [K] |
| Temperature | TCooIn_nominal | 273.15 + 20 | Nominal coolant inlet temperature [K] |
| Temperature | TCooOut_nominal | 273.15 + 30 | Nominal coolant outlet temperature [K] |
| MassFlowRate | mAir_flow_nominal | Q_flow_nominal/(TAirOut_nomi... | Nominal air mass flow rate [kg/s] |
| MassFlowRate | mCoo_flow_nominal | -Q_flow_nominal/(TCooOut_nom... | Nominal coolant mass flow rate [kg/s] |
Modelica definition
model Passive
"Example model for a passive rear door heat exchanger"
extends Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Examples.BaseClasses.PartialExample;
Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Passive hex(
redeclare package MediumCoo = MediumCoo,
redeclare package MediumAir = MediumAir,
dat(
mAir_flow_nominal=mAir_flow_nominal,
mCoo_flow_nominal=mCoo_flow_nominal,
Q_flow_nominal=Q_flow_nominal,
TAirIn_nominal=TAirIn_nominal,
TCooIn_nominal=TCooIn_nominal,
cpAir_nominal=cpAir_default,
cpCoo_nominal=cpCoo_default))
"Passive rear door heat exchanger";
Sources.MassFlowSource_T airSou(
redeclare package Medium = MediumAir,
nPorts=1,
use_m_flow_in=false,
m_flow=mAir_flow_nominal,
T=TAirIn_nominal)
"Air source at nominal conditions";
equation
connect(senTAirIn.port_b, hex.portAir_a);
connect(hex.portAir_b, senTAirOut.port_a);
connect(senTCooIn.port_b, hex.portCoo_a);
connect(hex.portCoo_b, senTCooOut.port_a);
connect(airSou.ports[1], senTAirIn.port_a);
end Passive;