modelZoneLwDistribution
Information
The Mean Radiant Temperature Network (MRTnet) approach from Carroll (1980) is used to compute the radiative heat transfer. This is a computationally efficient approach that does not require exact view factors to be known. Each surface exchanges heat with a fictive radiant surface, leading to a star resistance network.
Parameters
Parameter simVieFac may be set to true to simplify the
view factor calculation. This leads to a less accurate computation
of view factors, but this approach is more robust.
It may be used when the initial equation that computes the view factors does not converge.
References
[Liesen 1997]: R.J. Liesen, and C.O. Pedersen,
"An evaluation of inside surface heat balance models for cooling load calculations,"
ASHRAE Transactions, vol. 103, no. 2, pp. 485-502, 1997.
[Carroll 1980]: Carroll, J.A. 1980. An "MRT method" of computing radiant energy exchange in rooms. Proceedings of the 2nd Systems Simulation and Economics Analysis Conference, January 23-25
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | nSurf | Number of surfaces connected to the zone | |
| Boolean | simVieFac | false | Simplify view factor computation |
| Boolean | ignAss | false | Ignore asserts to simulate non-physical unit test models |
| Boolean | linearise | true | Linearise radiative heat exchange |
| Linearisation | |||
| Modelica.Units.SI.Temperature | Tzone_nom | 295.15 | Nominal temperature of environment, used for linearisation |
| Modelica.Units.SI.TemperatureDifference | dT_nom | -2 | Nominal temperature difference between solid and air, used for linearisation |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | port_a | Port for radiative heat exchange | |
| Modelica.Blocks.Interfaces.RealInput | A | Surface areas of connected surfaces | |
| Modelica.Blocks.Interfaces.RealInput | epsLw | Longwave surface emissivities of connected surfaces |
Revisions
-
April 26, 2024 by Jelger Jansen:
Improved asserts when view factor computation returns odd results. This is for #1272. -
February 18, 2020 by Filip Jorissen:
Improved warning when view factor computation returns odd results. See issue #1109. -
February 1, 2017 by Filip Jorissen:
Added option for disabling new view factor computation. See issue #663. -
January 20, 2017 by Filip Jorissen:
Changed view factor implementation. See issue #643. -
January 19, 2017 by Filip Jorissen:
Updated icon for issue #641 . -
January 19, 2017 by Filip Jorissen:
Propagated parameters for linearisation. -
July 12, 2016 by Filip Jorissen:
Changed implementation to be more intuitive. Added units to variables.