Abstract

The Brayton cycle is the ideal cycle for a gas-power engine. This project investigates the four Brayton cycle models which are simple Brayton cycle, Brayton cycle with intercooling reheating and regeneration (IRR), Brayton cycle with intercooling and regeneration (IR) and the Brayton cycle with polytropic compression and regeneration (PCR) to compare not only their efficiencies but economic costs and applicability. The simple Brayton cycle consists of 1 compressor,1 turbine,1 combustion chamber and exhaust. The (IR) cycle was modified from IRR Brayton cycle to reduce the fuel consumption by eliminating reheating process but intercooling process remains the same. Also, the Brayton cycle with polytropic compression that uses 1 compressor, is modified from simple Brayton cycle to reduce energy of compressor and intercooling work with water jacket to allow for the flow of cooling water around the compressor and through it. Cold-air standard assumption and steady-flow operating conditions are accepted through the simulation and kinetic and potential energies of flow are negligible. In the analysis, firstly, the energy analysis of the four modeled Brayton cycle is obtained, and the models of Brayton cycles are modeled by using temperature ratios (Tmin / Tmax) which are 0.2,0.25,0.33,0.4 and pressure ratio ranges between 1 to 25 in MATLAB to reach the maximum efficient type of Brayton cycle.