The Advanced Coal Flow Measurement System (ACFM™) is a state-of-the-art technology used in coal-fired power plants to measure the distribution of coal and combustion air in the furnace. No single factor is more important for combustion efficiency than the distribution of coal and combustion air, and the ACFM has been developed to ensure that the appropriate air-to-fuel ratio is achieved throughout the combustion zone.
Airflow Sciences Equipment manufactures two versions of the ACFM to fit the unique needs of our customers. Pictured on the right is the ACFM and the left is the ACFM V3.
The ACFM is a significant advancement over traditional testing systems, as it features fully computer-controlled vacuum adjustment and electronic data acquisition, eliminating the influence of operator error. The system has the capability to follow either the ISO 9931 or the ASME PTC 4.2 standards for pulverizer testing, providing accurate and reliable results.
Coal Pipe Balancing at a Power Generation Facility
In one recent case, a power generation facility in the western United States was experiencing extreme slagging on their water-wall tubes along with elevated LOI levels in their ash. HVT testing at the boiler nose also demonstrated a major oxygen imbalance across the furnace, indicating poor fuel balance.
As part of a comprehensive combustion study, the ACFM was used to determine the air and coal balance across each mill, all three of which were significantly outside of recognized industrial norms. Well-tuned boilers should have a relative air flow balance of +/- 5%, and a relative coal balance of +/- 10%. Each of the tested mills exceeded these deviations.
To improve the poor distribution demonstrated in the baseline testing, the test engineers manipulated the adjustable orifices installed in each of the coal pipes. This is typically an iterative process, where testing is repeated after each set of adjustments is made. The ACFM simplifies this activity through automation and remote-controlled test operation. With the ACFM, the iterative testing process is not only faster, but also safer for operators.
After three iterations of testing and adjustment, the relative balances were either close to or exceeding the recommended deviation standards. Overall, the pipe-to-pipe balance across all three mills was significantly improved for both the air flow and the coal flow. Additional HVT testing demonstrated that the oxygen imbalance across the furnace was dramatically improved over the baseline. The result for this power utility was reduced slagging and improved heat rate, allowing the plant to run with greater efficiency while reducing its maintenance costs.
Add an ACFM to Your Testing Toolbox
The ACFM has proven to be an essential tool in ensuring combustion efficiency in coal-fired power plants, allowing for safe, accurate, and fast testing of coal and combustion air. Power plants can customize their ACFM package with a wide variety of accessories to meet their operational needs.
Reach out to us today to learn how an ACFM can help improve combustion efficiency at your coal-fired power plant. Additional details can also be found on our product webpages (ACFM here or ACFM V3 here).