Paper 6: Design Features in Conventional Boiler Plant for the 1970s

This paper refers specially to current and future possible developments in the design of conventional steam plant in Britain. Trends in unit size and choice of steam cycles are discussed, and a comparison of generating costs with nuclear, oil, coal, and gas fuels is made.

The design of these large units involves the parallel development of fuel-firing equipment which must be closely integrated with the design of the whole plant. The mills being supplied to plants which will be commissioned in the early 1970s are described, with reference to possible future development. Developments in oil and gas burners for large steam generators are outlined.

Significant features of boiler designs for the 1970s are summarized. Welded-wall construction for drum-type and once-through steam generators, superheater and reheater designs, and auxiliary plant developments are discussed.

The application of automatic starting and shutdown to new boiler plants is reviewed and comment is made on future development. The possible introduction of combined gas and steam cycles, and the effect on the design of the steam plant, is considered. The paper also describes typical designs for steam-generating plant of 250 MW and 660 MW capacity.