modelActive
Extends from Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.BaseClasses.PartialRearDoorHeatExchanger (Partial model of a rear door heat exchanger with coolant and air ports).
Information
Model of an active rear door heat exchanger (RDHx) for IT racks.
In this configuration, an integrated fan drives the warm server exhaust air through
the heat exchanger mounted at the rear door of the rack.
The fan speed is modulated by a PI controller to maintain zero back pressure.
The fan power is reported through the output PFan.
The liquid coolant enters through portCoo_a and exits through
portCoo_b. The air enters through portAir_a (warm server
exhaust), passes through the fan and then through the heat exchanger, and exits through
portAir_b (cooled air leaving the rack).
The performance data are provided through the record dat of type
Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Data.Active.Generic.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Assumptions | |||
| Boolean | allowFlowReversalCoo (from PartialRearDoorHeatExchanger) | true | = false to simplify equations on coolant side, assuming, but not enforcing, no flow reversal |
| Boolean | allowFlowReversalAir (from PartialRearDoorHeatExchanger) | true | = false to simplify equations on air side, assuming, but not enforcing, no flow reversal |
| Nominal condition | |||
| Buildings.Fluid.DataCenters.Racks.RearDoorHeatExchangers.Data.Passive.Generic | dat (from PartialRearDoorHeatExchanger) | Heat exchanger performance data | |
| Dynamics › Conservation equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamics.SteadyState | Type of energy balance for fan |
| Fan controller | |||
| Real | k | 1 | Gain of PI controller |
| Modelica.Units.SI.Time | Ti | 10 | Integrator time constant of PI controller |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | portCoo_a (from PartialRearDoorHeatExchanger) | Coolant inlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | portCoo_b (from PartialRearDoorHeatExchanger) | Coolant outlet port | |
| Modelica.Fluid.Interfaces.FluidPort_a | portAir_a (from PartialRearDoorHeatExchanger) | Air inlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | portAir_b (from PartialRearDoorHeatExchanger) | Air outlet port | |
| Modelica.Blocks.Interfaces.RealOutput | PFan | Power consumed by rear door heat exchanger fan |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.HeatExchangers.DryCoilEffectivenessNTU | reaDooHex (from PartialRearDoorHeatExchanger) | Rear door heat exchanger | |
| Sensors.TemperatureTwoPort | senTAirReaDooHexIn (from PartialRearDoorHeatExchanger) | Air temperature entering rear door heat exchanger | |
| Buildings.Fluid.DataCenters.Racks.BaseClasses.Fan | fan | Rear door heat exchanger fan | |
| Buildings.Fluid.Sensors.TemperatureTwoPort | senTAirOut | Air temperature leaving rear door heat exchanger | |
| Buildings.Fluid.DataCenters.Racks.FanControllers.BackPressure | con | Controller for fan | |
| Sensors.Pressure | senPreIn | Inlet pressure | |
| Sensors.Pressure | senPreOut | Outlet pressure | |
| Sensors.TemperatureTwoPort | senTAirReaDooHexOut | Air temperature exiting rear door heat exchanger |
Revisions
-
September 18, 2026, by Michael Wetter:
First implementation.