The changing approach to on-line gas turbine compressor cleaning

The way power plant operators approach on-line gas turbine compressor cleaning has changed dramatically over the past two decades.

Shifting operating strategies, changes in the power generation market, and concerns about equipment reliability have all influenced how compressors are cleaned today.

As the industry continues to focus on efficiency, fuel savings, and operational flexibility, it’s worth revisiting how online compressor cleaning has evolved and whether current practices are delivering the best possible results.

How has online gas turbine compressor cleaning changed?

Over the past couple of decades, on-line gas turbine compressor washing has evolved, and it’s a good time to look critically at current practices and see if they’re fit for the industry in its current form. 

Historically, many gas turbines operated as baseload units, running continuously for long periods. Under those conditions, routine on-line gas turbine compressor washing was a standard maintenance practice because there were few opportunities for off-line cleaning.

However, industry conditions changed significantly in the late 1990s and early 2000s.

Power market deregulation, combined with the rapid construction of combined-cycle plants between 1999 and 2004, created excess generating capacity across much of the United States.

As a result, many facilities reduced or eliminated routine on-line washing programs.

At the same time, concerns began to grow about using detergents during on-line cleaning. Operators cited potential risks such as:

• Compressor blade damage
• Blade liberation events
• Downstream contamination

Some insurance providers declined to cover online detergent cleaning programs, while several turbine OEMs did not recommend detergent use during on-line washing on certain turbine models.

In many plants, gas turbine detergent cleaning was replaced with water-only washes, and greater emphasis was placed on periodic off-line cleaning.

How do operators clean gas turbine compressors today?

Many of today’s gas turbine operators continue to follow practices established during that period. Infrequent on-line washing, or water-only washing has become the norm, and many newer engineers have never worked under a different maintenance strategy.

Although many OEMs still recommend water-only online cleaning, compressor cleaning technology has advanced considerably over the past two decades. As a result, operators should evaluate not only what cleaning fluid they use, but also how effectively it reaches compressor blades.

Whether using water alone or a gas turbine cleaning solution, spray distribution and complete blade coverage play a critical role in cleaning effectiveness.

Optimising on-line washes – nozzle technology 

Field observations on some GE units suggested that during on-line water washing:

• Airflow pushed water toward the bellmouth
• Centre/root sections of blades appeared less effectively treated
• Coverage across the compressor face could become uneven

Historical images also showed:

• “Streaking” patterns during on-line washing
• Cleaner blade tips compared to root sections
• Evidence of uneven spray distribution

These observations demonstrate that cleaning performance depends on much more than the cleaning fluid itself.

Effective online washing requires:

1. Nozzle design
2. Nozzle location
3. Spray trajectory

Modern wash nozzle technology has improved significantly over earlier designs that often produced gaps in spray coverage and “scalloping” between adjacent spray patterns. Today’s systems are designed to deliver more uniform atomization and better coverage across the entire compressor face, helping operators achieve more consistent cleaning results.

This article looks deeper into the importance of blade coverage and spray distribution. 

Looking beyond water vs. detergent

The discussion surrounding on-line gas compressor cleaning has traditionally focused on whether water or detergent should be used. However, that debate overlooks another critical factor - ensuring the cleaning solution actually reaches every compressor blade.

Even the most effective cleaning chemistry cannot perform well without uniform spray coverage.

As fuel costs continue to rise and operators seek every opportunity to improve turbine efficiency and output, optimizing online cleaning systems has become increasingly important.

Summary

Over the past 20 to 25 years, the industry has shifted away from frequent online washing and, in many cases, from using cleaning detergents during online cleaning. At the same time, a better understanding has emerged of how spray distribution and blade coverage directly influence cleaning effectiveness.

Advances in nozzle technology now provide operators with new opportunities to improve online cleaning performance, maximize compressor efficiency, and reduce the impact of fouling on gas turbine output.

At Rochem FYREWASH®, we specialize in gas turbine compressor cleaning solutions that help operators improve performance while minimizing maintenance costs.

Contact us to learn how optimized online cleaning can improve your plant’s efficiency and long-term reliability.

References

Rochem FYREWASH

https://www.sciencedirect.com/science/article/abs/pii/S0306261912001109 [Accessed 8/6/26]