Gas turbine compressor cleaning systems and chemicals for all types of gas turbines
A 50MW gas turbine with some degree of fouling, showing a 3% power decrease and 1% heat rate increase can suffer a loss of performance costing more than $500,000 annually. Understanding our clients need to keep their gas turbines operational at the highest possible output and lowest possible cost is what drives our passion. Rochem provide solutions to your gas turbine fouling challenges. These include a range on On-crank (crankwash) and On-line (fired wash) engine cleaning systems and chemicals.
How do compressors foul?
In spite of the highly sophisticated air cleaning systems available today, ingression of air borne particles into the gas turbine compressor is inevitable. As a result, fouling of air-path surfaces in the turbines compressor occurs., leading to performance loss and increased fuel consumption. Worldwide field experience has clearly demonstrated that axial flow compressor deterioration during operation accounts for the major portion of gas turbine related performance loss. Of the total gas turbine performance loss approximately 70% can usually be attributed to compressor deterioration due to blade fouling. Fouling of axial flow compressor blade is generally attributed to airborne particulate in the sub-micron to 10 micron size range and this will the major source of fouling. Another possible source of compressor fouling is oil leakage from the compressor rotor inlet bearing.
Why does this fouling affect my engine's performance
Axial flow compressor blading creates smooth airfoil shapes similar to an airplane wing. Consequently blade performance may deteriorate due to increases in surface roughness or due to shape changes brought by blade deposits. Blade deposits or fouling reduces both compressor airflow and overall thermal efficiency. In addition to compressor discharge, pressure drops due to the reduced air mass flow rate through the turbine nozzle. Fouling will therefore be recognised by a drop in turbine output for a given exhaust gas temperature, accompanied by a lower compressor discharge pressure and increase in heat rate resulting in higher fuel consumption.
How do you clean your compressor
- Hand clean - this method is time consuming, labour intensive and can lead to high loss of revenue due to shutdown.
- Abrasive cleaning – in this type of compressor cleaning crushed walnut shells, or similar, are ingested into the air inlet whilst the engine is running. Contaminants are then removed by ‘shot blasting’. However performance is often short lived and potential damage to surface coatings and cooling path blockages may result in permanent performance loss.
- Wet cleaning - the most effective and least damaging is to perform a strict washing regime combining on-line and off-line washing using Fyrewash chemicals and treated water.
- On-line gas turbine compressor cleaning is performance with the engine running on load. A wash solution is injected into the air inlet using specially designed nozzles to ensure comprehensive wetting of the compressor blades and effective cleaning through the compressor stages.
- Off line cleaning is performed with the engine shutdown and cranking, a wash solution is injected into the air inlet using specially designed nozzles to ensure comprehensive wetting of the compressor blades and effective cleaning through the compressor stages.
What equipment do I need?
Rochem design and manufacture specialist nozzles. These nozzles produce optimum droplet size distribution and wetting of the compressor inlet to provide effective cleaning of the compressor blades while eliminating potential blade surface erosion. We use Computational Fluid Dynamics and 3D modelling techniques, together with field testing to continually develop and improve our system efficiency. Our wash delivery systems are designed for ease of use and minimum maintenance whilst providing control of fluid delivery to the on-line and off-line nozzles.