Combustion Engineering V2M9 Boiler

The Combustion Engineering marine boiler V2M9 cutaway view.
By locating fixed points of support at approximately midheight of the boiler, expansion of the lower portion of the boiler is downward and expansion of the upper portion of the boiler is upward. This arrangement resuits in reduced amplitudes of expansion as compared to those which would occur if the boiler was supported at the bottom.
In order to avoid problems of tube vibration in the convection generating bank, Combustion Engineering's designers placed a limitation on the dimensions between steam and water drums. Many of the higher powered ships have experienced severe vibration problems and it is essential that the boiler components must be designed to avoid natural frequencies which are within the range of low frequency excitations.

The most outstanding feature of the V2M9 boiler is the combustion.

The boiler is a vertical two-drum dropped-furnace boiler. The burners are located at each of the four corners of the furnace and the burners are aligned to be tangential to a circle in the centre of the furnace. This arrangement gives a rotary motion to the combustion gases within the furnace, with improved turbulence and air/fuel mixing. This lengthens the fuel-particle residence time in the boiler and allows combustion to be completed before the gases pass into the convection generating bank and superheaters.

V2M9 boiler,
water and steam flow diagram

Blue: the downcomers lead the water from the steam drum to the water drum and the water walls headers.
Red and blue: the evaporation tubes and the waterwalls lead the water and steam emulsion back to the steam drum.
Red:the steam passes through the superheater before it leaves the boiler for the consumers.