Investigation on performance of Cycle combined Brayton and ambient pressure gas turbine

Abstract

This paper addresses the configuration layout and the study on performance of Ambient Pressure Gas Turbine Cycle (APGC). The performance of cycle combined Brayton Cycle (BC) and APGC which is with regenerator is further simulated and analyzed. These models for simulation are developed with the software ASPEN PLUS. The APGC flow sheet and relative processing parameters are conducted and the investigating result is presented. The APGC operates under atmospheric pressure condition which can recover the exhausted gas from the topping power plant to increase the power production and the overall energy utilization efficiency of the power plant itself. Compared with the conventional micro gas turbines, APGC takes many advantages. As a result, APGC system will be introduced and the new combined system will also be created to contribute to save the energy and reduce the fuel consumption. The promising cycle combined BC and APGC with regenerator is presented and discussed with BC as the topping cycle and APGC as the bottom one. Based on the data of 350kw small gas turbine, the results of combined system output and electric efficiency are obtained by varying the upper cycle pressure ration from 2 to 12, at any value of bottom turbine expansion pressure between 0.1bar and 0.9bar. For micro/small gas turbine power unit, when the bottom turbine pressure was 0.6 bar. and the upper pressure ratio was 3.5, the combination system gives the best electric efficiency 35.2%. By analyzing the performance results of various combined cycles, the best performance could be obtained by varying the bottom turbine expansion pressure and the upper pressure ratio.