7 warning signs your gas turbine compressor needs cleaning

Gas turbine compressors suffer from foulant build-up: when contaminants from the air (and other sources) adhere to the blades, reducing internal volume, interrupting airflow and corroding/eroding surfaces. 

It’s essential to clean your gas turbine compressor to keep it running efficiently and prolong its service life. But how do you know when to wash it?

Today we’re looking at the telltale signs your gas turbine compressor needs a clean, keeping you ahead of the game when it comes to gas turbine maintenance while avoiding costly unscheduled shutdowns. 

The seven signs your gas turbine compressor needs cleaning

Gas turbine compressor fouling is a gradual process as microscopic contaminants slowly accumulate. It’s very unlikely you’ll notice a significant, sudden reduction in power output, but rather a subtle decrease in performance over time. This means operators are rarely given an obvious signal that something is wrong until there’s a sudden failure of equipment. 

While the subtle decrease in output may seem unimportant, operators are forced to compensate by using more and more fuel to achieve the same results, and the costs mount up. 

While the process is gradual, you shouldn’t ignore it. Keep a look out for these telltale signs your gas turbine compressor needs cleaning and keep it as efficient as possible:

1. Gradual reduction in power output

It’s important to keep track of your gas turbine’s performance. One of the earliest signs of gas compressor fouling is a gradual reduction in power. Power loss will be almost unnoticeable on a day-to-day basis, so look back at historical performance data to check if output is dropping. The culprit could be fouling, and it’s time to carry out a compressor wash.

2. Increased fuel consumption

An alternative to a gradual reduction in power output is a gradual increase in fuel consumption. As efficiency declines, more fuel may be used to generate the same power output. 

Monitor fuel consumption to see if it’s creeping up. If so, a compressor wash could remove foulants, restore lost power and reduce fuel consumption.

3. Higher exhaust gas temperatures

Increasing exhaust gas temperature can be an early indication of compressor deterioration and fouling. As the turbine is forced to work harder and harder to maintain output, the temperature increases. Keep a log and look back to see if there are notable changes. 

4. Falling compressor efficiency or pressure ratio

Look at changes in compressor efficiency, airflow or pressure ratios, which are all useful indicators of compressor health. Even small changes can signal fouling is developing, so it’s time to take action with a compressor wash. 

5. Visible contamination

While numerical data is extremely useful, you may be able to physically see foulant build-up. Observation windows give you a view to the inner workings of the gas turbine compressor, while routine inspections/borescope examinations can reveal contamination and other issues. 

Visual inspections should not replace operational data but can aid the diagnosis of any noted power loss, increased fuel consumption or higher than expected exhaust temperatures. 

6. Operating environment

While it’s not exactly a sign, it’s worth mentioning that you should carefully consider your operating environment. Gas turbines operating in coastal, desert, industrial or offshore environments are generally exposed to higher levels of airborne contamination. Foulants tend to build up much more quickly than you might expect, and frequent compressor washing should be a default part of the maintenance schedule. 

7. Increasing operating trends

Finally, rather than relying on single measurements, it’s better to monitor performance trends over time. A downward curve of power output and a gradual increase in fuel consumption and exhaust temperature indicate compressor performance is deteriorating. If this is the case, it’s time for a wash.

What type of gas turbine compressor wash is best?

Foulant build-up is gradual, so the best way to keep it under control is:

• On-line washes every day/every few days
• Occasional off-line washes e.g. every few months
• Manual cleaning during major maintenance

This three-pronged method of washing keeps foulant build-up to a minimum while also combating stubborn deposits to keep your gas turbine compressor in peak condition. Experience shows this approach is much better and more cost-effective than waiting for obvious, significant performance deterioration or indeed equipment failure.

Get in touch

There’s a lot to think about when you’re responsible for the health and productivity of a gas turbine power site. While a well-managed cleaning schedule should keep your turbine compressor in good condition, keep an eye on those telltale signs we’ve outlined to monitor cleanliness and maximise efficiency.

If you’re interested in introducing or improving gas turbine compressor washes, we’re here to help. Our specialised cleaning chemicals and equipment are backed by decades of experience in the industry and chosen at thousands of sites around the globe.

Please browse our product range and get in touch to see how we can help.