Heat Recovery System Control & Compressor Monitoring

The heat (energy) recovered is displayed continually on the Simatic HMI. The calculations for this are made within the S7-315 PLC. Information from the air compressor is polled via Modbus rtu protocol. The compressor is automatically started via the PLC when the downstream plant process requires additional compressed air.

Sole responsibility for software development and associated documentation, PLC / HMI programming. AutoCAD (symbols to IEC-60617). RS485 Modbus communications. This project furthered our experience with Step 7 PLC programming software. Configured PID loop control for several modulating values and developed intuitive HMI screens to allow the technicians to view the performance of each loop in the form of historical data trends. Electrical schematics and interface diagrams provided to stringent Sandvik specifications. Project specific function blocks had to be coded in the PLC, for example, the conversion of two integers (whole & fraction) into a single floating point value and vise-versa.

HMI implemented, Siemens MP 377 15″ touch screen panel, designed for industrial environments. Users tap the relevant “buttons” on the screen to access other pages or to enter in set-point values, change an event, log-in or initiate control over the system. Users can switch between English or Swedish for convenience.