| 摘要 |
A hot spot detection system (78) at one location that is fixed with respect to the rotor (12), and a temperature suppression system (62) at another location that is fixed with respect to the rotor. The suppression system is automatically energized by the hot spot detection system when a threshold temperature is detected. Preferably, the suppression system includes one or more pipes (66) that span the radial dimension of the heating element compartments in the rotor. The detection system can be in the conventional location, on the trailing edge (40) of the air inlet duct (32) of the air preheater. The suppression piping (66) is preferably located in the hot end, or air discharge duct (34), of the air preheater. Depending on the location of the suppression piping with respect to rotor rotation, a timing device (100) is preferably employed to start and stop the flow of suppression water into the rotor, just prior to and after the hot spot passes under the piping.
|
