To regulate the heat transfer characteristics only at an updated section selectively within a short period such as a test operation period, by admixing an inorganic compound having a freezing point corresponding to gas temperature to fuel or combustion air system as an additive after a heating tube group or the heating tube wall is updated.
In a boiler 20 burning fossil fuel, an arbitrary aged heating tube group or the heating tube wall is updated. Subsequently, an inorganic compound having a freezing point corresponding to the temperature of gas passing through the updated section is admixed to fuel, combustion air system or recirculated exhaust gas in a furnace 1 as an additive in the form of powder or liquid mixed with powder and particles. Heat transfer characteristics at the updated section are regulated by contaminating the surface of the updated clean heating tube during test operation period of several hours or days. Since the range is selected and contamination is accelerated only at the updated section, recovery of plant efficiency is accelerated resulting in the enhancement of performance and efficiency.
FUKUMOTO FUMIO
SAKAI KAZUTO
MATSUDA JUNICHIRO
