Sofema Aviation Services (www.sassofia.com) looks at delivering an Increased Aircraft Fuel Efficiency and overall Decrease in Fuel Consumption with Optimized Core Engine Cleaning.
Consider the value of 1% saving of the fuel costs as a result of paying specific attention to the health of the engines and improving performance and reducing the operating temperature of the engines
What is a Compressor Wash?
The major source of engine power loss, and the most easily correctable, is contaminant fouling of the compressor. (Carbon, oils in fact anything that is in the ambient air will get into the compressor). ‘Oil and grease act as ‘glue’ on the compressor blading and will trap and hold other material.
Compressor washes are a routine procedure for those who work are familiar with turbine engines. So to consider what takes place during a compressor wash.
To see the positive affect on engine performance and life cycles.
Measuring Engine Thermal Efficiency
Thermal efficiency is the ratio of the net ”work” produced by the engine to the chemical energy supplied by the fuel.
The three most important factors affecting thermal efficiency are turbine inlet temperature, compression ratio, and the component efficiencies of the compressor and turbine. (Other factors that affect thermal efficiency are compressor inlet temperature and burner efficiency.)
Contamination to the compressor section affects the thermal efficiency, and therefore the performance of the engine. Not only does it affect performance, but damage to the blades caused by contamination can lead to engine failure.
What Contaminants are Found Within the Engine
Because of the large volume of air introduced into engine compressors, a lot of this contamination is introduced into the engine. (Fine particles of dirt, oil, soot, and other foreign matter in the air.)
The centrifugal forces of the compressor throw this contamination outward so that it builds up to form a coating on the casing, vanes, and the compressor blades.
The accumulation of these contaminants reduces the aerodynamic efficiency of the blades, resulting in deteriorating engine performance.
Engine Performance Deterioration
This loss of efficiency can lead to unsatisfactory acceleration and high exhaust gas temperature (EGT). Contamination, especially in high salt operating environments, can also lead to corrosion of the engine components.
In order to maintain engine performance and reduce the corrosive effects on the engine, the debris that builds up in the compressor needs to be removed. We do this through routine compressor washes.
“The chemicals in a compressor wash solution break down the organic bonds of the contaminants, allowing the air stream and/or the fresh water rinse to remove the contaminants out of the engine.”
The OEM specifies which chemicals can be used to wash the compressor.
Always refer to the OEM procedures, because they are engine specific.
Water Quality
Water quality is an important part of effective compressor washes. OEMs, always recommend de-ionized or de-mineralized water,”
Establishing a Wash Schedule
Compressor wash schedules will vary from one operator to the next. Compressor wash procedures vary from manufacturer. A typical compressor wash involves three steps — a chemical wash, a water rinse, and an engine run.
After connecting the appropriate fixtures to the engine, a chemical is injected in the engine while the compressor is turned.
The wash is followed by a fresh water rinse. The rinse ensures that all of the contaminants dislodged by the wash are flushed out of the engine. This is followed up by an engine run.
The airflow from the engine run helps further clean out the dislodged contaminants and dries out the engine.
Sofema Aviation Services offers EASA Compliant Regulatory and Vocational Training including Engine Condition Trend Monitoring. For details please see www.sassofia.com or email office@sassofia.com
