Miejska Energetyka Cieplna — Kołobrzeg

‘Construction of a peak-load gas-fired boiler house at Szarych Szeregów Street in Kołobrzeg’.

The scope of the design-and-build contract, based on the Functional and Utility Programme, included the design and construction of:

• a main electrical power supply system comprising a main switchboard with a reactive-power compensation section and a connection for a 150 kVA generator set, operating at 400 VAC, 50 Hz, with a 100 kW connection capacity. The main switchboard includes outgoing circuits for fire zones and for an explosion-hazardous zone (ATEX (EX) II 3G Ex nA IIC T4), together with an explosive and toxic gas detection system based on IEC/EN 61508. The system disconnects the main power supply and closes the main gas valve at Safety Integrity Level SIL 2. It is integrated with a POLON 6000 fire alarm control system compliant with PN-EN 54-2 and PN-EN 54-4, which disconnects power at the main switchboard. The main switchboard was also equipped with an M2M telemetry system based on a GSM (LTE) modem, providing access to the intranet through an encrypted OpenVPN tunnel and using the integrated Modbus TCP/IP communication protocol.
• a control system for a gas-fired boiler house with two 2.5 MW boilers, comprising a power and control switchboard equipped with a PLC, variable-frequency drives, an operator panel, Modbus TCP/IP, Modbus RTU, Ex-zone Modbus RTU and M-Bus digital communications, and an emergency-stop system compliant with IEC 62061 at Safety Integrity Level SIL 1. The power and control switchboard serves 10 pumps, including nine pumps with integrated variable-frequency drives controlled via Modbus TCP/IP; four on/off electric actuators; five modulating electric actuators; two modulating electric valves; 17 analogue transmitters; four heat meters (M-Bus); two gas meters (Modbus RTU Ex); four remote devices (Modbus RTU); an operator panel (Modbus TCP/IP); and integration with the power and control switchboards of the BOSCH gas-fired boilers.