This paper describes the supercharged steam-generating cycle as currently employed in the U. S. Navy. In this cycle gas pressure in the boiler varies with load to a design peak of five atmospheres. The boiler receives its air for combustion from an air compressor which is powered by boiler exhaust gases expanding through a gas turbine. A historical background of the cycle and its components follows. Since a number of systems of the supercharged type have been and are being subjected to test at the Naval Boiler and Turbine Laboratory, the components of the systems, with particular emphasis on the boilers, are described. Advantages and disadvantages of the system are detailed and evaluated. The conclusion is that advantages are significant and that suspected problems or disadvantages do not need to exist if it is understood that the supercharged steam generator is regarded as not just another boiler, but rather as a precision piece of equipment. The test program at the Naval Boiler and Turbine Laboratory is defined as to scope and objectives. Test results are discussed and modifications required as a result of tests are described. Finally, there is a short review of shipboard operating experience to the present time. A major point developed is that the introduction of a new type boiler to the Navy's Fleet required an RDT&E effort, a full-scale test program, a new appreciation of the art of boiler design and manufacture, and a realistic and well-defined training program, plus the development of new ancillary equipment. The most important of the other equipments required is, of course, a compact and reliable supercharger set (air compressor and gas turbine) to provide air for combustion. The successful design of a compact supercharger set is the key to the use of the supercharged steam cycle.
Numerical investigation of coal-water fuel combustion in two-chamber furnace of a low-power boiler
