[L1] 1 Overview [L2] 1) Definition [L4] - A power conversion device that compresses air with a compressor, burns it with fuel in a combustion chamber, and converts the energy generated by combustion/explosion into kinetic energy through a turbine. [L4] - An engine type that gains power by heating gas with the combustion heat of fuel and injecting high-temperature, high-pressure gas onto turbine blades (classified into Internal Combustion Gas Turbines and External Combustion Gas Turbines). [L2] 2) Gas Turbine Configuration [L3] ① Compressor [L3] ② Combustor [L3] ③ Turbine [L2] 3) Features of Gas Turbine Engine [L4] - The linear arrangement of Compressor-Combustion Chamber-Turbine results in low vibration generation and is advantageous for creating high RPM. [L4] * Optimal for high-speed rotation but not suitable for low-speed rotation. [L4] - Small and lightweight with high output relative to size (Power-to-weight ratio is higher than internal combustion engines). [L4] - Uniform torque but low thermal efficiency. [L4] - Low vibration, but high noise. [L4] - Wide fuel usage range. Low-grade fuel can be used, and separate filters are unnecessary. [L4] - Requires large power for starting. [L1] 2 Gas Turbine Cycles [L2] 1) Brayton Cycle [L4] - The ideal cycle for gas turbines, used in aircraft, automobiles, and power generation exhaust gas cycles. [L4] - Proceeds in the process of Reversible Adiabatic Compression → Isobaric Heating → Reversible Adiabatic Expansion → Isobaric Heat Rejection. [L4] * Both compression and expansion occur within rotating machinery. [c] Source: Korea National University of Transportation [c] Source: Korea National University of Transportation [L2] 2) Stirling Cycle [L4] - Basically based on the Carnot cycle, but isentropic processes are replaced by isochoric processes. [L4] - A cycle consisting of 2 isochoric processes and 2 isothermal processes. [L4] - Uses regeneration in the isochoric process, and the regenerator stores working fluid energy for a certain period of the cycle. [L4] * Isothermal Compression: Working fluid is compressed and heat is released to the outside. [L4] * Isochoric Heating: Heat is supplied from the inside (regenerator) at a constant volume. [L4] * Isothermal Expansion: Working fluid receives heat from the outside and expands. [L4] * Isochoric Heat Rejection: Heat is released to the inside (regenerator) at a constant volume. [L2] 3) Ericsson Cycle [L4] - Basically based on the Carnot cycle, but isentropic processes are replaced by isobaric processes. [L4] - A cycle consisting of 2 isothermal processes and 2 isobaric processes. [L2] 4) Lenoir Cycle [L4] - A cycle consisting of isochoric, isobaric, and adiabatic processes. [L2] 5) Atkinson Cycle [L4] - A cycle consisting of isobaric, isochoric, and 2 adiabatic processes.