Gas Turbine Compressor Washing

Description of the system
Gas turbines experience a degradation of performance during operation as the result of deposits on internal components of the compressor. Compressor deposits occur with the ingested air. The fouling of this section will reduce the thermal efficiency and power output of the gas turbine.

Two methods are used to determine the cleanliness of the compressor:

• Visual inspection

• Performance monitoring

1 -Visual inspection

• Unit shutdown, the visual inspection includes inspection of the compressor inlet, bellmouth, inlet guide vanes and the first stage of the compressor blades.

• If the fouling is caused by "dry" contaminants a water solution is enough.

• If the deposits are "oily", a water/detergent wash and water rinse should be performed.

2 -Performance monitoring

• The performance data is obtained by running the unit at steady state base load and recording output, exhaust temperature, inlet air temperature, barometric pressure, compressor discharge pressure and temperature and fuel consumption.

• If performance analysis indicates compressor fouling, it should be verified by a visual inspection.

Equipment concerning the compressor washing consists of a piping from the customer's connection on the turbine base, of motor-driven valves 20 TW-1 and 20 TW-3 and of push-buttons 43 TW-1/PB of those same valves, and a compressor spray manifold feeding the compressor through spray nozzles located in the compressor bell-mouth. There are also some customer's connections on the drain pipings.