The Inverted Brayton Cycle for Waste-Heat Utilization

The inverted Brayton cycle, which can be simply defined as one in which hot gas is first expanded through a turbine to low pressure, is then cooled at constant pressure, and lastly, is recompressed to the initial pressure, has been shown to give attractive incremental gains in thermal efficiency, and large returns on investment, when added to a conventional shaft-power gas turbine exhausting into a waste-heat boiler. When the inverted Brayton cycle is applied by itself as a method of obtaining shaft power from the hot waste gas stream, there appears to be range of temperature and pressure ratios at which the cycle is competitive with other methods of waste-heat utilization.