Thermodynamic optimization of an open cycle of an externally fired micro gas turbine. Part 2: Performance optimization

The power and efficiency of the open regenerative cycle of an externally fired micro gas turbine power plant without blade cooling with pressure drop irreversibilities are optimized based on the model established using thermodynamic optimization theory in Part 1 of this article by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the net power output, and the maximum has an additional maximum with respect to the compressor pressure ratio. When the optimization is performed with the constraints of the fixed fuel flow and the plant size, the net power output and the thermal conversion efficiency of the cycle can be maximized again by properly allocating the fixed flow area among the compressor inlet and the power turbine outlet. The numerical examples show the effects of the design parameters on the power output and heat conversion efficiency and that both the power output and conversion efficiency increase with the increase in the effectiveness of the regenerator, which is different from the open cycle regenerator gas turbine power plant.