Question 296Steam Plants - Assistant Engineer

The correct answer is A) feed water entering the boiler. The boiler economizer is a device that preheats the feed water before it enters the boiler. By recovering waste heat from the boiler's exhaust gases, the economizer can increase the overall efficiency of the boiler system by reducing the amount of energy required to heat the feed water to the desired temperature. This improves the overall thermal efficiency of the boiler, making it a more energy-efficient system. The other options are incorrect because they do not accurately describe the function of the boiler economizer. The economizer does not provide additional heat to the steam leaving the superheater (B), the fuel oil entering the furnace (C), or the air supply entering the furnace (D).