Boiler full power capability will be adversely affected if what percentage of generating tubes are plugged?

The full power capability of a boiler can be significantly impacted when more than 5 percent of the generating tubes are plugged. When generating tubes become plugged, it restricts the flow of combustion gases and steam, leading to a decrease in heat transfer efficiency and a rise in back pressure.

As the percentage of plugged tubes increases, more surface area is lost for heat exchange, impacting the boiler's ability to maintain optimal pressure and temperature levels necessary for generating steam effectively. This situation leads to a reduced output of steam, ultimately compromising the overall performance and efficiency of the boiler system.

In contrast, plugging less than 5 percent of generating tubes may not have a noticeable effect on the performance of the boiler. Systems are often designed with tolerances that allow for a small percentage of tubes to be out of service without critically affecting operation. Therefore, concerns intensify notably only after surpassed the 5 percent threshold, making it essential for boiler operators to monitor and maintain the integrity of the generating tubes to ensure efficient and safe operations.