.Buildings.Fluid.SolarCollectors.BaseClasses.PartialSolarCollector

Information

This component is a partial model of a solar thermal collector. It can be expanded to create solar collector models based on either ASHRAE93 or EN12975 ratings data.

Notice

As mentioned in the reference, the SRCC incident angle modifier equation coefficients are only valid for incident angles of 60 degrees or less. Because these curves behave poorly for angles greater than 60 degrees the model does not calculatue either direct or diffuse solar radiation gains when the incidence angle is greater than 60 degrees.

The heat capacity of the collector without fluid is estimated based on the dry mass and the specific heat capacity of copper. This heat capacity is then added to the model by increasing the size of the fluid volume. Note that in earlier implementations, there was a separate model to take into account this heat capacity. However, this led to a translation error if glycol was used as the medium, because during the translation, the function T_ph for Modelica.Media.Incompressible.Examples.Glycol47 had to be differentiated, but this function is not differentiable.

References

EnergyPlus 7.0.0 Engineering Reference, October 13, 2011.
CEN 2006, European Standard 12975-1:2006, European Committee for Standardization

Revisions

• December 11, 2023, by Michael Wetter:
  Corrected implementation of pressure drop calculation for the situation where the collectors are in parallel, e.g., if sysConfig == Buildings.Fluid.SolarCollectors.Types.SystemConfiguration.Parallel.
  Changed assignment of computeFlowResistance to final based on dp_nominal.
  This is for Buildings, #3597.
• September 16, 2021, by Michael Wetter:
  Changed lat from being a parameter to an input from weather bus.
  This is for IBPSA, #1477.
• April 14, 2020, by Michael Wetter:
  Changed homotopyInitialization to a constant.
  This is for IBPSA, #1341.
• November 12, 2019, by Filip Jorissen:
  Set prescribedHeatFlowRate=false to avoid a division by zero at zero flow when using SteadyState dynamics.
  This is for Buildings, issue 1636.
• April 27, 2018, by Michael Wetter:
  Corrected displayUnit.
  This is for Buildings, issue 912.
• January 22, 2016, by Michael Wetter:
  Corrected type declaration of pressure difference. This is for #404.
• February 8, 2015, by Filip Jorissen:
  Propagated multiple parameters from LumpedVolumeDeclarations, set prescribedHeatFlowRate = true in vol.
• September 18, 2014, by Michael Wetter:
  Removed the separate instance of Modelica.Thermal.HeatTransfer.Components.HeatCapacitor and added this capacity to the volume. This is in response to https://github.com/lbl-srg/modelica-buildings/issues/276.
• June 25, 2014, by Michael Wetter:
  Improved comments for tilt to address https://github.com/lbl-srg/modelica-buildings/issues/246.
• October 8, 2013, by Michael Wetter:
  Removed parameter show_V_flow in declaration of instance res.
• January 4, 2013, by Peter Grant:
  First implementation.