modelWetCoilDiscretized

Coil with discretization along the flow paths and humidity condensation

Extends from DryCoilDiscretized.

Information

Model of a discretized coil with humidity condensation. This model is identical to Buildings.Fluid.HeatExchangers.DryCoilDiscretized but in addition, the mass transfer from fluid 2 to the metal is computed. The mass transfer is computed using a similarity law between heat and mass transfer, as implemented by the model Buildings.Fluid.HeatExchangers.BaseClasses.MassExchange. See this model for details.

This model can only be used with medium models that implement the function enthalpyOfLiquid and that contain an integer variable Water whose value is the element number where the water vapor is stored in the species concentration vector. Examples for such media are Buildings.Media.Air and Modelica.Media.Air.MoistAir.

Components

TypeNameDefaultDescription
Modelica.Units.SI.HeatFlowRateQSen2_flowQ2_flow - QLat2_flowSensible heat input into air stream (negative if air is cooled)
Modelica.Units.SI.HeatFlowRateQLat2_flowBuildings.Utilities.Psychrometrics.Constants.h_fg*mWat_flowLatent heat input into air (negative if air is dehumidified)
RealSHRQSen2_flow/noEvent(if (Q2_flow > 1E-6 or Q2_flow < -1E-6) then Q2_flow else 1)Sensible to total heat ratio
Modelica.Units.SI.MassFlowRatemWat_flowsum(hexReg[:].ele[:, :].vol2.mWat_flow)Water flow rate

Revisions

  • July 5, 2022, by Antoine Gautier:
    Restored the addition of heat to mas.T in Buildings.Fluid.HeatExchangers.BaseClasses.HexElementLatent.
    This is for #3065.
  • May 26, 2022, by Michael Wetter:
    Removed addition of heat to mas.T in Buildings.Fluid.HeatExchangers.BaseClasses.HexElementLatent to correct latent heat exchange calculation.
    This is for #3027.
  • January 12, 2019, by Michael Wetter:
    Corrected wrong use of each.
  • April 14, 2017, by David Blum:
    Added heat of condensation to coil surface heat balance and removed it from the air stream. This gives higher coil surface temperature and avoids overestimating the latent heat ratio that was observed in the previous implementation. The code change was in Buildings.Fluid.HeatExchangers.BaseClasses.HexElementLatent.
    This is for #711.
  • April 12, 2017, by Michael Wetter:
    Added new variables QSen2_flow, QLat2_flow and SHR.
  • July 29, 2016, by Michael Wetter:
    Redeclared Medium2 to be Modelica.Media.Interfaces.PartialCondensingGases because it is used in vol2, which requires the medium to extend from this subclass.
    See also issue 547.
  • June 29, 2014, by Michael Wetter:
    Removed parameter dl which is no longer needed.
  • December 13, 2013, by Michael Wetter:
    Corrected wrong connection connect(hexReg[nReg].port_b1, pipMan_b.port_b) to connect(hexReg[nReg].port_a1, pipMan_b.port_b) in the base class Buildings.Fluid.HeatExchangers.DryCoilDiscretized. This closes issue https://github.com/lbl-srg/modelica-buildings/issues/194, which caused the last register to have no liquid flow.
  • September 10, 2008 by Michael Wetter:
    Added values for stateSelect attributes.
  • August 13, 2008 by Michael Wetter:
    First implementation.