.Buildings.UsersGuide.ReleaseNotes.Version_5_1_0

Information

Version 5.1.0 adds new libraries, new components and improves various existing components. Version 5.1.0 updates the license to a 3-clause BSD license. It is backward compatible with versions 5.0.0 and 5.0.1.

This release adds a model for propylene glycol - water mixtures, a model for long pipes suited for district heating and cooling simulations, a new valve model whose opening characteristics can be fit to measured data, and idealized models that allow to prescribe the temperature and humidity in any part of a fluid flow system.

The following new libraries have been added:

Buildings.Media.Antifreeze.PropyleneGlycolWater Package with medium model for propylene glycol - water mixture. The concentration and the medium temperature for which the properties are evaluated can be set when instantiating the medium.

The following new components have been added to existing libraries:

Buildings.Fluid
Buildings.Fluid.Actuators.Valves.TwoWayPolynomial Two-way valve with opening characteristics specified by a polynomial. This model may be used if a valve characteristics needs to be matched to measured data.
Buildings.Fluid.FixedResistances.PlugFlowPipe Pipe with heat loss and transport of the fluid using a plug flow model. This model is applicable for simulation of long pipes such as in district heating and cooling systems.
Buildings.Fluid.Sources.PropertySource_T
Buildings.Fluid.Sources.PropertySource_h
Model that changes the fluid properties of the medium that flows through it based on input signals. These idealized models can be used to force a certain temperature, enthalpy or humidity in a fluid flow system.

The following existing components have been improved in a backward compatible way:

Buildings.Airflow.Multizone
Buildings.Airflow.Multizone.DoorDiscretizedOpen
Buildings.Airflow.Multizone.DoorDiscretizedOperable
Removed term that assures non-zero flow rate in each path, reformulated flow balance to ensure that model is symmetric, and improved implementation to reduce number of calculations.
This is for IBPSA, issue 937.
Buildings.Applications.DataCenters
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialParallelElectricEIR Added constrainedby to declaration of chiller.
This is for issue 1118.
Buildings.Controls.OBC.ASHRAE.G36_PR1
Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.SetPoints.Supply Revised implementation of fan speed control signal calculation to remove the hysteresis blocks.
This is for issue 1153.
Buildings.Controls.OBC.CDL
Buildings.Controls.OBC.CDL.Continuous.Line Improved documentation and icon, and added a warning if the limits are used and x1 > x2.
Buildings.Fluid.SolarCollectors
Buildings.Fluid.SolarCollectors.ASHRAE93
Buildings.Fluid.SolarCollectors.EN12975
Improved calculation of heat loss.
This is for issue 1100.
Buildings.Fluid.Sources
Buildings.Fluid.Sources.Boundary_pT
Buildings.Fluid.Sources.Boundary_ph
Buildings.Fluid.Sources.FixedBoundary
Buildings.Fluid.Sources.MassFlowSource_T
Buildings.Fluid.Sources.MassFlowSource_h
Refactored models to allow using Xi rather than X as an input.
By default, the check on the medium base properties is now removed to reduce translation and simulation time.
This is for IBPSA, issue 882.
Buildings.Fluid.Storage.Stratified Refactored tank to allow modeling of tanks that have multiple inlets or outlets along the height. The tank now has for each control volume a fluid port that can be connected from outside the model.
This is for issue 1182.
Buildings.Utilities.IO
Buildings.Utilities.IO.Python27 Added option for a Python object to be passed from one Python function invocation to the next. This allows to build up a Python data structure (or to instantiate a Python object), and do computations on this object at each function invocation. For example, a Model Predictive Control algorithm or a machine learning algorithm, implemented in Python, could be fed with data at each time step. It could then store this data and use the current and its historical data to feed its algorithm. Based on this algorithm, it could output a control signal for use in another Modelica model.
The function Buildings.Utilities.IO.Python27.Functions.exchange now takes two additional arguments: A class that contains a pointer to the Python interpreter (for efficiency, as this avoids initializing Python at each call), and a flag that determines whether the Python function returns an object and receives this object at the next invocation. See Buildings.Utilities.IO.Python27.UsersGuide and Buildings.Utilities.IO.Python27.Real_Real for how to use these two arguments.
Models that use Buildings.Utilities.IO.Python27.Real_Real will still work as before. The change only affects the low-level function Buildings.Utilities.IO.Python27.Functions.exchange.
Buildings.Utilities.IO.Python27 Corrected LibraryDirectory annotation.
This is for issue 1160.

The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):

Buildings.Fluid.Interfaces
Buildings.Fluid.Interfaces.PrescribedOutlet Corrected error that caused the old model do not track TSet and X_wSet simultaneously.
This is for IBPSA, issue 893.

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