Cheng cycle

The Cheng cycle is a retrofit to the gas turbine cycle. The Cheng cycle involves the heated exhaust gas from the turbine being used to make steam in a heat recovery steam generator (HRSG). The steam so produced is injected into the gas turbine's combustion chamber to increase power output. The process can be thought of as a parallel combination of the gas turbine Brayton cycle and a steam turbine Rankine cycle. The cycle was invented by Prof. D. Y. Cheng of the University of Santa Clara who patented it in 1976.