To improve the efficiency of respective boilers, by extension, the whole system while considering especially feed water temperature.
There include are a plurality of boilers 2 whose combustion amounts are proportionally controlled. Exhaust gas from each of the boilers 2 is passed through an economizer 13, and in the economizer 13, feed water to be supplied to the boilers 2 is preheated by exhaust gas heat. In order to detect a temperature of feed water to be passed or passed through the economizer 13, a temperature sensor 17 is arranged. A plurality of different ranges of combustion amounts are set as proportional bands of proportional control, and when the detection temperature of the temperature sensor 17 is a set temperature or less, the combustion amounts are controlled by a low combustion proportional band. When the detection temperature exceeds the set temperature, the combustion amounts are controlled by a middle combustion proportional band. When controlling the number of boilers 2 to be driven and respective combustion amounts in accordance with using loads of steam, the number of boilers 2 to be driven by the proportional band selected based on the detection temperature of the temperature sensor 17 is maximized.
SASAKI TSUTOMU
SUZUKI HIDENORI
| JP2012017965A | 2012-01-26 | |||
| JP2004190989A | 2004-07-08 |