.Buildings.UsersGuide.ReleaseNotes.Version_5_0_0 .Buildings.UsersGuide.ReleaseNotes.Version_5_0_0Version 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. |