세계 각국은 온실가스 배출을 줄이기 위하여 활발한 노력을 하고 있다. 한국도 노후화된 석탄발전을 폐지하고 LNG 발전으로 전환하는 정책을 추진하고 있다. 그러나, 한국은 가스터빈 제작 기술이 국산화되지 않아서 해외 제작사로부터 전량 수입하여 설치하고 있다. 따라서, 본 논고에서는 가스터빈 발전산업에 대한 국내·외 환경을 살펴보고, 이를 기반으로 PEST-SWOT-AHP 방법론을 적용하여 한국형 가스터빈 기술개발 및 보급 확대 추진전략을 제안하였다. 연구결과, 한국형 가스터빈 기술개발과 보급 확대 전략은 1) 가스터빈 기술개발 및 사업화 촉진을 위한 발전공기업의 역할 강화, 2) 온실가스 감축을 위한 LNG 발전 비중 확대, 3) 정부의 적극적인 가스터빈 산업 생태계 조성 노력, 4) LNG 발전소 건설에 대한 국민 공감대 형성 등으로 요약할 수 있다.

As the capacity of renewable power generation facilities rapidly increases, the variability of electric power system and gas turbine power generation is also increasing. Therefore, problems may occur that require urgent repair while the gas turbine rotor is stopped. When the gas turbine rotor turning is stopped and then restarted, if the turning period is not appropriate, severe vibration may occur due to rotor bending. As a result of the experiment, it was confirmed that normal operation is possible when the gap data measured at the start of rotor turning after maintenance work is similar to the existing value. And the vibration value at the start of rotor turning was lower as the rotor temperature was lower or the stop period was shorter.

Gas turbine engines are widely used as prime movers of generator and propulsion system in warships. This study addresses the problem of designing a DS-based PID controller for speed control of the LM-2500 gas turbine engine used for propulsion in warships. To this end, we first derive a dynamic model of the LM-2500 using actual sea trail data. Next, the PRC (process reaction curve) method is used to approximate the first-order plus time delay (FOPTD) model, and the DS-based PID controller design technique is proposed according to approximation of the time delay term. The proposed controller conducts set-point tracking simulation using MATLAB (2016b), and evaluates and compares the performance index with the existing control methods. As a result of simulation at each operating point, the proposed controller showed the smallest in , which means that the rpm does not change rapidly. In addition, IAE and IAC were also the smallest, showing the best result in error performance and controller effort.

In this study, defects generated in the YSZ coating layer of the IN738LC turbine blade are investigated using an optical microscope and SEM/EDS. The blade YSZ coating layer is composed of a Y-Zr component top coat layer and a Co component bond coat layer. A large amount of Cr/Ni component that diffused from the base is also measured in the bond coat. The blade hot corrosion is concentrated on the surface of the concave part, accompanied by separation of the coating layer due to the concentration of combustion gas collisions here. In the top coating layer of the blade, cracks occur in the vertical and horizontal directions, along with pits in the top coating layer. Combustion gas components such as Na and S are contained inside the pits and cracks, so it is considered that the pits/cracks are caused by the corrosion of the combustion gases. Also, a thermally grown oxide (TGO) layer of several μm thick composed of Al oxide is observed between the top coat and the bond coat, and a similar inner TGO with a thickness of several μm is also observed between the bond coat and the matrix. A PFZ (precipitate free zone) deficient in γ' (Ni3Al) forms as a band around the TGO, in which the Al component is integrated. Although TGO can resist high temperature corrosion of the top coat, it should also be considered that if its shape is irregular and contains pore defects, it may degrade the blade high temperature creep properties. Compositional and microstructural analysis results for hightemperature corrosion and TGO defects in the blade coating layer used at high temperatures are expected to be applied to sound YSZ coating and blade design technology.

Most of gas turbine combined cycle power plants are located in urban areas to provide peak load and district heating. However, NOx(nitrogen oxides) of exhaust gas emission from the power plants cause additional fine dust and thus it has negative impact on the urban environment. Although DLN(dry low NOx) and multi-stage combustors have been widely applied to solve this problem, they have another critical problem of damages to combustors and turbine components due to combustion dynamic pressure. In this study, the effect of different fuel ratio on NOx emission and pressure fluctuation was investigated regarding two variable conditions; combustor stages and power output on M501J gas turbine.

In this study, we analysed the influence of the flow and performance of the generated micro gas turbine with different rotational speeds. CFD analysis was also performed using commercial code called ANSYS CFX 14.5. It adopted the turbine of radial flow type suitable for power generation for small rotating equipment. The number of blades was designed with each radial turbine 8, vane nozzle 14. The boundary layer flow analysis was widely used to the SST model. Mass flow rate of the turbine was 1.45 kg/s. While the rpm varies from 38,000rpm to 48,000rpm under various boundary conditions, the distributions of Mach number and pressure were numerically analyzed for electric power output, turbine isentropic efficiency. We analyze the inlet pressure, outlet temperature, electric power output, turbine isentropic efficiency. It compared maximum and minimum revolution through CFD analysis. Power output of maximum revolution has been increased 18% more than minimum revolution. Isentropic efficiency of maximum revolution has been increased 16.5% more than minimum revolution. Therefore, maximum power output was 332kW, amaximum isentropic efficiency was 33.2%.

가스 터빈은 기동 및 정지 횟수가 많기 때문에 열피로나 취화 현상으로 인한 가스터빈 케이싱의 균열 또는 케이싱의 플랜 지면에서 고온고압 가스의 누설이 발생할 가능성이 높다. 따라서 가스터빈 케이싱의 구조안전성 및 플랜지면에서의 누설평 가는 반드시 수행되어야 하는 부분이다. 본 논문에서는 유한요소해석을 바탕으로 터빈 케이싱의 ASME B&PVC VIII-2 구 조안전성 평가 및 접촉압력을 통한 누설 평가 그리고 볼트의 구조안전성 평가를 진행하였다. 또한 가스터빈 케이싱의 유한 요소모델링 및 해석/평가 방법을 제안하여 가스터빈 개발에 활용할 수 있게 하였다.

가스 터빈은 기동 및 정지 횟수가 많기 때문에 열피로나 취화 현상으로 인한 가스터빈 케이싱의 균열 또는 케이싱의 플랜지면에서 고온고압 가스의 누설이 발생할 가능성이 높다. 따라서 가스터빈 케이싱의 구조안전성 및 플랜지면에서의 누설평가는 반드시 수행되어야 하는 부분이다. 본 논문에서는 유한요소해석을 바탕으로 터빈 케이싱의 ASME B&PVC VIII-2 구조안전성 평가 및 접촉압력을 통한 누설 평가 그리고 볼트의 구조안전성 평가를 진행하였다. 또한 가스터빈 케이싱의 유한요소모델링 및 해석/평가 방법을 제안하여 가스터빈 개발에 활용할 수 있게 하였다.

This research is to investigate the performance analysis of micro gas turbine for power generation with three different numbers of the nozzle vane in the micro gas turbine. Velocity, pressure. and temperature distributions of fluid over the flow domain of the turbine and turbulent kinetic energy of three different turbine blades are numerically calculated for the optimum design of turbine blade with two different rotational speeds of the turbine blade (10000 and 20000 RPM). Ultimately, the energy-efficient and maximum power-generated shape of the nozzle vane are determined through two different rotational speeds of the turbine with three shapes of the nozzle vane (6, 8, and 12 EA).

Gas turbines for power generating operate in a very high temperature condition and use natural gas for fuel. For this reason, many cases of damage happen at hot gas parts which are severely affected by high temperature gas and many cases of explosion occur by fuel gas. So a lot of efforts should be made to prevent hot gas parts damage and gas explosion accidents. Though there are many damage cases and explosion accidents, it is very difficult to find out the root causes of hot gas parts damage caused by gas explosion due to gas leakage in the heat exchanger for air cooling and gas heating. To prevent gas turbine from damage caused by gas explosion, removal of leakage gas from gas turbine is inevitably required before firing the gas turbine and installing alarm systems is also required for detecting gas leakage at stop valve to turbine while shut down.

Gas turbines generating power operate in high temperature condition and use natural gas as fuel. For that reason, there are many cases where damage is done to the hot gas parts caused by the high temperature and many accidents occur like gas explosions, then various efforts are needed to maintain the hot gas parts and prevent accidents. It is difficult to find the root causes of damage to the hot gas parts from the gas explosion caused by gas leakage through rotor cooling air line from fuel gas heat exchanger during the shut down. To prevent gas turbine from damage, removal of gas leakage inside of gas turbine is required by purging the turbine before firing, improving the fuel gas heating system and installing alarm systems for detecting gas leakage from stop valve to turbine while the gas turbine has shut down.

The use of the gas turbine for power supply is increasing recently. Accordingly, the operation and maintenance cost of the gas turbine is gradually increasing and the various efforts to cut the cost are needed. For an operation and maintenance cost saving of the gas turbine, reductions of the new purchasing charge and the reproduction repair cost of the hot gas parts are required through more effective operation and life management methods for the hot gas parts. The hot gas parts are the main parts of the gas turbine and they are replaced with the periodic. In this research, efficient operation and life management methods for the hot gas parts were presented with the cases. The methods were analyzed and verified based on real data and the cases for improving a lifetime were utilized in the field.

The energy efficiency of gas turbine using LNG as a fuel has reached to less than about 40% even for the H class gas turbine. To increase the energy efficiency, in theoretical analysis, the maximum value of fuel efficiency can be obtained via the equally large value of the mixing rate and reaction rate in the harmonic-mean type overall reaction rate expression. Even if the delayed mixing rate can be overcome successfully by the strategy of the practically proved lean-burn method, however, the critical problem caused by the retarded reaction rate caused by the excess air has to be solved in order to make any breakthrough of the engine or gas turbine fuel efficiency. To do this, a series of systematic numerical calculation has been made for the evaluation of the lean-burn CH4 flame feature with the addition of small amount of H2 or HHO (H2+1/2O2, water electrolysis gas). To maintain lean burn state, the flow rate of methane was greatly reduced less than 50% of the standard flow rate. The addition of HHO or H2 heating value has increased steadily from 5, 10 and up to 20% of the 100% CH4 flow rate. And investigation of flame characteristics such as peak flame temperature and its location together with the temperature profile has been made through numerical calculation for a gas turbine combustor. For the standard case of 100% CH4 injection, the flame temperature profile was observed to increase steadily from the primary combustor region to gas turbine inlet. This is exactly corresponds to the temperature profile appeared in a heating process with constant pressure assumption in a typical Brayton cycle. However, for the case of co-burning with H2 or HHO with only 40 and 50% CH4 injection, the peak flame temperature appears near the upstream primary region and decreases significantly along the downstream toward turbine inlet. A detailed discussion further has been made for the flame characteristics with the change of added fuel amount and its type. In summary, the addition of the H2 and HHO gas with the reduced amount of the CH4 flow rate results in quite different temperature profile expected from the standard Brayton cycle. Further this kind of flame feature suggests the possibility of high fuel efficiency together with the reduction of the metallurgical thermal damage of the turbine blade due to the decreased gas temperature near turbine inlet.

전 세계적으로 에너지 소비가 급속하고 늘고 있는 추세이며, 화학연료를 이용한 전기 생산은 기후변화를 야기시키므로 새로운 형태의 친환경적인 발전 시스템의 개발이 매우 중요한 현안으로 떠오르고 있다. 전력수급의 많은 부분을 원자력과 화력발전에 의존하고 있는 우리나라의 경우 증가하는 전력 수요를 가스터빈을 이용한 복합발전이나 열병합 발전이 분담을 해야 하므로 가스터빈 관련 연구 개발은 매우 중요하다고 할 수 있다. 최근에는 분산발전에 대한 관심이 고조되면서 이에 적합한 동력원으로 고려되고 있는 마이크로 터빈 및 이에 대한 응용시스템 연구개발이 국내외에서 활발히 수행되고 있다. 마이크로 가스터빈은 중대형 가스터빈에 비해 개발기간이 짧고 개발비 규모가 작아 세계시장에서도 경쟁력있는 상품이 될수 있을 것으로 판단된다. 본 연구는 60KW 출력의 마이크로 가스터빈을 대상으로 메탄/수소, 메탄/산소-수소 혼합기체를 혼합한 연료에 대한 연소 특성 및 내부 열유동을 수치해석적 연구를 통하여 검토하였다. 수소 및 산소-수소 혼합연료의 체적분율을 변화시켜 변수연구를 수행하였다. 연구 결과를 살펴보면 연료 중 수소 및 산소/수소 기체의 체적분율을 높일수록 연소기 내부의 primary zone의 화염온도가 현저히 상승하며 연소기 내부의 고온영역이 넓게 분포되는 것을 볼 수 있다.이는 수소나 산소-수소 기체로 대체했을 때 수소의 빠른 연소속도에 의해 단시간에 화염온도의 상승을 이룰수 있고 수소의 강한 반응성과 높은 열확산성으로 인하여 순신간에 가스터빈 내부의 연료와 공기의 난류혼합을 활발하게 하여 가스 터빈의 효율 향상에 일조한다는 것이다. 수소비율에 따라 가스터빈의 연소성능과 관련이 있는 primary zone의 평균온도, 출구의 평균온도, 출구에서의 온도의 편차비(pattern factor)와 같은 결과를 검토하여 의미있는 결과를 도출하였다. 향후 최적 운전을 위한 적절한 연료의 혼합비율은 가스터빈의 형상 및 규모 등 다양한 변수를 고려하여 도출하는 것이 필요할 것으로 판단된다.

가스터빈 기관은 우주항공, 발전 플랜트뿐만 아니라 해상운송 분야에 사용되는 원동기로서 매우 중요한 역할을 하고 있다. 그러나 그 구조가 복잡하고 연소과정에서 시간지연 요소가 포함되어 있어 가스터빈 기관을 잘 제어할려면 정교한 수학적 모델링이 필요하다. 본 논문 에서는 가스터빈 기관의 주요 구성품인 가스발생기, PLA 액추에이터, 미터링 밸브에 대한 모델링 기법을 설명한다. 또한, 가스터빈 기관의 시 운전 데이터를 기초로 몇 가지 정상상태 때의 동작점에서 서브모델을 구하고, 각 서브모델에 대해 비선형 비례적분미분 제어기를 설계하여 기 관의 속도를 제어하는 방법을 제안한다. 제안하는 비선형 제어기는 비선형 함수로 구현되는 3가지 이득을 사용한다. 비선형 제어기의 파라미터 는 제어시스템의 목적함수를 최소화하는 관점에서 실수코딩 유전자알고리즘으로 동조한다. 제안한 방법은 가스터빈 기관에 적용하고 시뮬레이 션을 실시하여 그 유효성을 확인한다.