Procedure: Start and Run Up a Gas Turbine and Heat Recovery Steam Generator

Purpose. This procedure sets out the checks and sequence for starting a gas turbine, bringing its heat recovery steam generator into service and loading the unit to dispatch.

1.Scope

This procedure applies to a start of either gas turbine at Newport West from a cold, warm or hot state, whether after a shutdown or an outage. It must be performed by an authorised unit controller with a field operator on plant.

2.Step 1: Pre-start checks

The unit controller must confirm that no permits are open on the unit in the register, that all isolations are restored, that fuel gas supply pressure and quality are within limits, that fire protection is available and that the auxiliary systems are running. The field operator must walk the unit and confirm the plant matches the control system status.

• No open permits on the unit
• Fuel gas pressure and calorific value in range
• Fire protection and gas detection available
• Lubrication oil, cooling and instrument air in service
• Heat recovery steam generator drum levels and vents set

3.Step 2: Start sequence

The controller must initiate the automatic start sequence and must monitor purge, ignition, acceleration and synchronisation. A hold at any step must be diagnosed before the sequence is repeated. Vibration, exhaust temperature spread and bearing temperatures must be watched against the limits in the operating envelope.

4.Step 3: Heat recovery steam generator warm up

The controller must control the hot gas control system and drum pressure rise to the warm up rate for the start type, must manage drum levels through the feedwater control and must open the steam line drains and vents until steam quality is acceptable to the steam turbine.

5.Step 4: Load to dispatch

The unit must be loaded at the ramp rate allowed by the operating envelope and the dispatch instruction. Emissions control systems must be confirmed in service before the unit passes the load at which the licence limit applies.

6.Step 5: Record

The controller must record the start time, start type, synchronisation time, any holds and the final load in the Operations Log, and must raise a work order for any defect found during the start.