FastSmoothBuildings

FastSmoothBuildings is a Modelica library of buildings and their heating, cooling and ventilation systems written as smooth, event-free, explicit ordinary differential equations:

• in closed loop, with its own smooth controllers, it follows the Modelica Buildings library: layered walls, windows with the angular optics and gas gaps of Buildings, long-wave and solar exchanges in the rooms, radiators, valves, pumps, boilers, heat pumps with their buffer, ventilation with heat recovery, photovoltaics;
• with the controls of its systems as inputs, rumoca translates it into a CasADi model, ready for model predictive control, state estimation and calibration with IPOPT.

It has no dependency, not even the Modelica Standard Library, and runs in OpenModelica, Dymola and rumoca alike.

The library was developed as the FastModel package of trano, which generates its models from a YAML description of a building; its history is in this repository. In trano's validation, the models it generates pass the 27 cases of ASHRAE Standard 140 (BESTEST), with heating and cooling loads within 1.1 % of Buildings on average, and follow Buildings within 0.02 to 0.10 K on the zone temperatures of a six-zone house (BESTEST).

Install

The Modelica library is the folder FastSmoothBuildings:

• OpenModelica: add the folder that holds it to MODELICAPATH and loadModel(FastSmoothBuildings), or loadFile("<path>/FastSmoothBuildings/package.mo");
• Dymola, OMEdit: open FastSmoothBuildings/package.mo.

The Python package fastsmoothbuildings carries the library and tells tools where it is:

pip install fastsmoothbuildings

import rumoca

import fastsmoothbuildings

session = rumoca.Session(roots=[str(fastsmoothbuildings.LIBRARY)])  # rumoca reads the library from its folder
model = session.loads(source, model="MyBuilding.building").to_casadi()

text = fastsmoothbuildings.bundle()  # or the whole library as one file, to embed it in a generated model

fastsmoothbuildings.LIBRARY is the folder of the library (rumoca reads every Modelica file below a root, so give it the library itself), fastsmoothbuildings.ROOT the folder that holds it, to put on MODELICAPATH, and fastsmoothbuildings.__version__ the version of the library (its version annotation).

The library

The library reference has a page per class, from its Modelica documentation.

Package	Content
UsersGuide	Conventions, the smooth functions and the rules that keep a model translatable by rumoca
Examples	Rooms, hydronic circuits, ventilation and ideal systems to simulate
BoundaryConditions	Weather data, solar position, Perez sky model, irradiance on tilted surfaces
Envelope	Walls, floors, roofs (layers split into sublayers as Buildings), windows (panes, gas gaps, frame, overhangs and side fins)
Zones	Room air, long-wave exchange between surfaces, distribution of the transmitted sun, internal gains
Hydronics	Water circuits with set flows (optimal control) or pressure-driven flows (closed loop): pipes, pumps, valves, three-way valves, junctions, EN 442 radiators, boilers, air-to-water heat pumps with buffer
Ventilation	Ducts and air handling unit with heat recovery
Controls	Event-free controllers: hysteresis as fast bistable states, anti-windup PI, emission, collector, boiler and heat pump controls, every smoothing width a parameter
HVAC	Ideal heating and cooling
Electrical	Photovoltaics
Utilities	Smooth functions (regStep, smoothMax, smoothMin, smoothLimit, ...), convection laws, valve characteristics

A model built from these classes stays an explicit ODE: no when, pre, sample or event-generating if; switches are regStep transitions whose width is a parameter. rumoca sizes arrays and evaluates subscripts from literal parameters only, so the records of the constructions carry their layer and node counts written out (see the User's Guide).

Examples

Example	What it shows
Examples.FreeFloatingRoom	The room of BESTEST case 600FF under clear winter days
Examples.IdealHeatingRoom	The same room heated to 20 °C and cooled to 27 °C by an ideal system
Examples.TwoZones	Two rooms with an internal wall, a slab on the ground, an on/off and a proportional room controller
Examples.VentilatedRoom	Balanced ventilation with heat recovery
Examples.BoilerCircuit	Gas boiler, pump, three-way valve, radiator and thermostatic valve, pressure-driven flows (closed loop)
Examples.BoilerCircuitSetFlows	The same circuit with set flows, as the model of optimal control has them
Examples.HeatPumpCircuit	Air-to-water heat pump with its buffer and two radiators
Examples.Photovoltaics	Arrays facing south and west

The Validation packages of Utilities, Envelope and Controls exercise the smooth functions, the schedules, the gas gaps, the overhangs and side fins, the hysteresis and the PI controller. Every example translates with rumoca, and its CasADi model integrated by CVODES follows the OpenModelica results within 0.01 K on the rooms.

License

BSD 3-Clause; the portions that follow the Modelica Buildings Library carry its license too (see LICENSE).