Version 5.0.0 is a major new release that contains new packages to model control sequences, a package with control sequences from ASHRAE Guideline 36 and a package with pre-configured models for data center chilled water plants. All models simulate with Dymola 2017FD01, Dymola 2018 and with JModelica (revision 10374).
The following major changes have been done:
Buildings.Controls.OBC.CDL has been added.
This package provides elementary blocks to implemented control sequences.
The blocks conform to the Control Description Language specification
published at https://obc.lbl.gov.
Buildings.Controls.OBC.ASHRAE.G36_PR1 has been added.
This package contains control sequences for variable air volume flow systems
according to ASHRAE Guideline 36, public review draft 1.
The implementation uses blocks from the above described
Buildings.Controls.OBC.CDL package, and conforms to the
Control Description Language specification.
The following new libraries have been added:
| Buildings.Applications.DataCenter | Library with component models and pre-configured system models for data centers. |
| Buildings.Controls.OBC | Library with basic control blocks and ready-to-use control sequences
from the OpenBuildingControl project
(https://obc.lbl.gov). The subpackage Buildings.Controls.OBC.ASHRAE
contains control sequences
for HVAC systems as described in ASHRAE Guideline 36.The subpackage Buildings.Controls.OBC.CDL
contains libraries with basic control blocks.
These are a part of a Control Description Language (CDL)
currently being developed, which is used to compose
the sequences in Buildings.Controls.OBC.ASHRAE.
The intent of this implementation is that
Modelica models that are conformant with the CDL
can be translated to product lines of different control vendors.
|
| Buildings.Fluid.Humidifiers | Package with spray air washer, steam humidifier and a humidifer that adds a water vapor mass flow rate that is proportional to the control input. |
The following new components have been added to existing libraries:
| Buildings.Fluid.HeatExchangers | |
| Buildings.Fluid.HeatExchangers.Heater_T Buildings.Fluid.HeatExchangers.SensibleCooler_T |
Added these new components to allow modeling a heater and a sensible-only cooler that use an input signal to ideally control their outlet temperature, with optional capacity limitation and optional first order dynamics. |
| Buildings.Fluid.MassExchangers | |
| Buildings.Fluid.Humidifiers.SprayAirWasher_X Buildings.Fluid.Humidifiers.SteamHumidifier_X |
Added component which allows setting the outlet water vapor mass fraction using an input signal, and controlling it ideally with optional capacity limitation and optional first order dynamics. |
| Buildings.Fluid.Sources | |
| Buildings.Fluid.Sources.MassFlowSource_WeatherData | Added component which allows prescribing a mass flow rate that has thermal properties obtained from weather data. |
The following existing components have been improved in a backward compatible way:
| Buildings.Fluid.Chillers | |
| Buildings.Fluid.Chillers.Carnot_TEva Buildings.Fluid.Chillers.Carnot_y |
Added approach temperature to avoid
too large COPs if the temperature lift is small. This is for IBPSA, #698. |
| Buildings.Fluid.HeatExchangers | |
| Buildings.Fluid.HeatExchangers.DryCoilCounterFlow Buildings.Fluid.HeatExchangers.DryCoilDiscretized Buildings.Fluid.HeatExchangers.WetCoilCounterFlow Buildings.Fluid.HeatExchangers.WetCoilDiscretized |
Improved model so that for certain parameters (dynamic balance,
or steady-state balance and no reverse flow,
or hA-calculation that is independent of temperature),
two fast state variables can be removed. This is for Buildings, #678. Added approximation of diffusion, which is needed for very small flow rates which can happen if fans are off but wind pressure entrains cold air through the HVAC system. This is for Buildings, #1038. |
| Buildings.Fluid.HeatPumps | |
| Buildings.Fluid.HeatPumps.Carnot_TCon Buildings.Fluid.HeatPumps.Carnot_y |
Added approach temperature to avoid
too large COPs if the temperature lift is small. This is for IBPSA, #698. |
| Buildings.Fluid.Movers | |
| Buildings.Fluid.Movers.FlowControlled_dp | Added optional input signal for differential pressure measurement, which will then be tracked by the model. |
| Buildings.Fluid.Sensors | |
| Buildings.Fluid.Sensors.TemperatureTwoPort | Improved optional heat loss model. This is for IBPSA, #840. |
| Buildings.Fluid.SolarCollectors | |
| Buildings.Fluid.SolarCollectors.ASHRAE93 Buildings.Fluid.SolarCollectors.EN12975 |
Changed models for incidence angles below 60°
in order to increase the accuracy near sunrise and sunset. This is for #785. |
| Buildings.ThermalZones.Detailed | |
| Buildings.ThermalZones.Detailed.MixedAir | Added an optional input that allows injecting trace substances, such as CO2 release from people, to the room air. |
The following existing components have been improved in a non-backward compatible way:
| Buildings.Fluid | |
| Buildings.Fluid.HeatExchangers.HeaterCooler_T | Renamed Buildings.Fluid.HeatExchangers.HeaterCooler_T
to Buildings.Fluid.HeatExchangers.PrescribedOutlet
as it now also allows to set the outlet water vapor mass fraction.For Dymola, a conversion script makes this change. This is for IBPSA, #763. |
| Buildings.Fluid.MassExchangers.Humidifier_u | Moved model to Buildings.Fluid.Humidifiers.Humidifier_u.Removed parameters use_T_in and T,
and removed input connector T_in, as these are no
longer needed.For Dymola, the conversion script will remove the parameter settings. For Dymola, a conversion script makes this change. This is for #704. |
| Buildings.Fluid.Interfaces | Renamed PrescribedOutletState to PrescribedOutlet
and removed PrescribedOutletStateParameters.This is for IBPSA, #763. |
| Buildings.Fluid.HeatExchangers | Removed the function
Buildings.Fluid.HeatExchangers.BaseClasses.appartusDewPoint
as it was nowhere used, and it also has no validation test.This is for Buildings, #724. |
The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
| Buildings.Airflow | |
| Buildings.Airflow.Multizone.EffectiveAirLeakageArea | Corrected error in computation of A which was
A=CD/CDRat * L * dpRat^(0.5-m)) rather than
A=CDRat/CD * L * dpRat^(0.5-m)).See #743. |
| Buildings.Controls | |
| Buildings.Controls.Continuous.OffTimer | Corrected implementation as the timer had the wrong
if the simulation did not start at time = 0.
After the first reset, the value was correct.See IBPSA, #743. |
| Buildings.Fluid | |
| Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger Buildings.Fluid.Interfaces.FourPortHeatMassExchanger |
Corrected assignment of Q_flow (or Q1_flow
and Q2_flow).
Previously, these variables were assigned only the sensible heat flow rate,
but they should include the latent heat exhange to be consistent with
the variable naming, and because the cooling coils interpret these variables
as if they contain the latent heat flow rate.This is for #704. |
| Buildings.Fluid.HeatExchangers.WetCoilCounterFlow Buildings.Fluid.HeatExchangers.WetCoilDiscretized Buildings.Fluid.HeatExchangers.BaseClasses.HexElementLatent |
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.HexElementLatentThis is for #711. |
| Buildings.Fluid.HeatExchangers.BaseClasses.HADryCoil | Corrected coefficient for temperature-dependency correction
of air-side convection coefficient.
By default, the convection coefficient
is assumed to be temperature-independent, in which cases this
correction has no effect on the results. This is for #698. |
The following uncritical errors have been fixed (i.e., errors that do not lead to wrong simulation results, e.g., units are wrong or errors in documentation):
| Buildings.HeatTransfer | |
| Buildings.HeatTransfer.Conduction.MultiLayer | Corrected wrong result variable R and UA.
These variables are only used for reporting.
All other calculations are not affected by this error.
|