Subject : Power Plant Engineering

Topic: Chap 6: Power Plant Economics

Difficulty: Medium

The feed water is pumped to the bottom header and this water is carried to the top header through a number of vertical tubes. Hot flue gases are allowed to pass over the external surface of the tubes. The feed water which flows upward in the tubes is thus heated by the flue gases. This pre-heated water is supplied to the boiler.

Advantages:

1. Feed water to the boiler is supplied at high temperature. Hence heat required in the boiler is less. Thus fuel consumption is less.
2. Thermal efficiency of the plant is increased.
3. Life of boiler is increased.