.Buildings.Fluid.Movers.Validation.PowerSimplified

Information

This example compares the power consumed by pumps that take three different control signals. Each pump has identical mass flow rate and pressure rise.

Note that for the instances Buildings.Fluid.Movers.FlowControlled_dp and Buildings.Fluid.Movers.FlowControlled_m_flow, we had to assign the efficiencies (otherwise the default constant efficiency of 0.7 would have been used). In these models, the power consumption is computed using similarity laws, but using the mass flow rate as opposed to the speed, because speed is not known in these two models. This is an approximation at operating points in which the speed is different from the nominal speed y_nominal because similarity laws are valid for speed and not for mass flow rate.

The figure below shows the approximation error for the power calculation where the speed y differs from the nominal speed y_nominal.

Contents

Name	Description
Medium	Medium model

Revisions

• March 21, 2023, by Hongxiang Fu:
  Replaced the pump with Nrpm signal with one with y signal. This is for IBPSA, #1704.
• March 8, 2022, by Hongxiang Fu:
  Refactored the model by replacing not use_powerCharacteristic with the enumeration Buildings.Fluid.Movers.BaseClasses.Types.HydraulicEfficiencyMethod. This is for #2668.
• October 15, 2021, by Hongxiang Fu:
  Fixed the image in the documentation which was cut off at the y-axis. This is for IBPSA, #1533.
• March 11, 2016, by Michael Wetter:
  Revised implementation by assigning the data record directly in the instances pump_dp and pump_m_flow, because using a parameter and assigning this parameter leads in OpenModelica to the error message expected subtype of record Buildings.Fluid.Movers.Data.Generic.
• March 2, 2016, by Filip Jorissen:
  Revised implementation for #417.
• November 5, 2015, by Michael Wetter:
  Changed parameters since the power is no longer a parameter for the movers that take mass flow rate or head as an input. This is for issue 457.
• November 22, 2014, by Michael Wetter:
  Revised implementation.