| 摘要 |
PURPOSE:To correctly detect a combustion vibration to prevent the same from occurring by operating a pressure amplitude deviation value between a pressure amplitude maximum value and a second pressure amplitude maximum value from a frequency component of a Foulier transformer to obtain a constant, and multiplying the pressure amplitude maximum value by the constant to obtain a true amplitude maximum value. CONSTITUTION:A pressure fluctuation component within a furnace of a boiler 1 is converted into an electrical signal by a pressure sensor 2, and is transformed into a frequency component if at a Foulier transformer 8. An entire pressure amplitude total value I0 on the frequency axis is operated by a Foulier converter 8. On the other hand, in a pressure amplitude maximum value Ipeak1 on the frequency axis and a neighboring frequency, one of both having a larger amplitude is set as a second pressure amplitude maximum value Ipeak2; a pressure amplitude deviation value DELTA I is operated by a subtractor 12. The pressure amplitude deviation value DELTA I is substituted by a function generator 13 to obtain a correction coefficient k, and the pressure amplitude muximum value Ipeak1 is multiplied by a correction coefficient k in a multiplier 14 to correct the same to a value close to a true maximum pressure amplitude I1. Previously obtained I0 and I1 are operated by a divider 11 to obtain L1/I0 (comustion vibration monitoring parameter). When R>=80% ;by an I1/I0 caluculator 6, an alarm is output to an alarming device 7. |
