SCADTS models the fluid, electrical distribution and associated wiring diagrams for power systems and maintains the system state in a MySql database which is accessible to other third party components. The simulation is based on finite difference solution using implicit numerical methods to ensure numerical stability. Each circuit corresponds to a particular fluid or electrical property. The fluid property also breaks down to two components, a condensible-fluid in the sub-cooled, saturated or superheated state and a non-condensible-fluid (Gas) that is modeled using the ideal gas equation. The condensible-fluid currently includes Water, R410a refrigerent and R137a refrigerent. The different equation sets and their solution correspond to the engine within SCADTS. The current engine selections include sub-cooled, multiphase, moist air and electrical each of which has a unique aspect to the solution.
Subcooled Fluid: The fluid is always subcooled with a constent heat cap.acity at constant pressure
Multiphase Fluid: The fluid may be in a subcooled, saturated or superheated state. Thermodynamic tables are used to compute scalar properties.
Electrical, Wiring Diagrams : The circuit solves for voltage and current using Publish/Subscribe to communicate with devices.
Moist Air: The boundary conditions include the relative humidity, temperature and total pressure and the partial pressures of air and water vapor are computed. Psychometric tables are used to compute all terms.
The properties of the fluid and electrical circuits as with all state parameters are stored in the MySql database and third party companies corcerned with proprietry information are able to control devices by mapping to the appropriate record and field in a database table to complete the control loop.
Devices are considered to be associated with one link as is the case with single port valves, pumps and compressors or multiport devices as is the case with tanks and multiport valves. In the former case single port devices are defined at the link while multiport devices are specified by the indices of their correpnding links or nodes. Heat exchangers are a particular case where there are two associated links corresponding to the hot or cold side and therefore have two link records. In general, the heat exchanger corresponds to two different circuits with their own thermodynamic properties. This is handled elegently by specifying the particular Account, Project, System and Circuit for each of the records.