SIMULATION OF A HVAC SYSTEM WITH THE HELP OF AN ENGINEERING EQUATION SOLVER

With the help of a so called “engineering equation solver” it is possible today to write directly executable equations. This means that the modeling can be made fully transparent and easy to adapt to the specific needs of any user. First principle models are very easy to produce, with reference to classical engineering processes. A same set of equations can even be used for different tasks as system sizing, parameter identification and simulation. An example of system modeling is presented in the paper; it concerns a whole chilling plant, with screw chillers, cooling towers, equilibrium bottle, ice storage system, heat exchangers and pumps. First principle models are separately demonstrated for all these components. Components models are then assembled together in order to represent the whole chilling plant. Simulation results obtained with this assembly are used in order to generate a set of polynomial equations, easy to connect to the building, through its “secondary” HVAC subsystems (air handling and terminal units).