Question 80Steam Plants - 1st Asst/Chief

The correct answer is D) feed water entering the boiler. The boiler economizer is a heat exchanger that extracts heat from the boiler's exhaust gases and transfers it to the feed water entering the boiler. This additional heat from the economizer helps to increase the temperature of the feed water, reducing the amount of energy required to convert the feed water into steam. 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 (A), the air supply entering the furnace (B), or the fuel oil entering the furnace (C).