Optimum performance comparative study of combined gas turbine partial oxidation cycle and reheat cycle

The present paper studies the general characteristics and evaluate the optimum performance of 2-stage POGT cycle augmented by a recuperation process. A comparative study of the performance of POGT cycle with that of a reheat cycle (RHGT) is discussed. The ranges of values of the controlling parameters of both cycles that give optimum performance (e.g. first law and second law efficiencies and net work output η_I, η_II, and w_net respectively) are determined and fitted into functional correlation equations. The effects of irreversibilities of the different composing units of the two cycles are accounted for in the study. The present findings can form a very important basis for a complete phenomenological design of POGT and RHGT cycles to achieve optimum performance. The study shows that for POGT cycle, at constant θ, the effect of x on q is very small compared to its effect on η_I and η_II , reaching their maximum values at about x=2.8. Mass ratio in has a constant decreasing effect on all cycle performance characteristics. Higher values of θ result in higher values of all cycle characteristics. For the RHGT cycle, x greatly effects all performance characteristics and has some limiting values at which w_net=η_I=0. Variation trends of cycle characteristics are similar in regards to the effect of θμ with their optimum values tends to lie between values of x of 1.6 and 2.6. Higher values of x decrease cycle performance. The comparative study shows that η_I for the RHGT cycle always exceeds that of the POGT cycle only at low values of x. Beyond these values of x, the POGT is better than the RHGT. The correlation equations relate optimum values of both cycle characteristics to the controlling parameters of each cycle. Irreversibilities of different units of each cycle have been accounted for in these equations