• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.195-196
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• 2012

This paper describes combustion tuning methodology of double-swirl gas turbine combustor using six sigma tools. This methodology is consist of five steps-Define, Identify, Design, Optimize and Verify (DIDOV). First, the NOx reduction target was defined in the step design; second, the current status of the plant was diagnosed in the step of identify; third, the vital few control parameters to achieve the defined target were determined by analyzing the correlation between the control parameters and NOx emissions in the step of design; fourth, the optimum condition was derived from one of the six sigma tools in the step of optimize; finally, the optimum condition was verified by applying the condition to the gas turbine combustor in the step of verify. As a result of the suggested method, averaged NOx emissions were reduced by more than 70% and the standard deviation was improved by more than 60%. Thus, this methodology can be attributed to the efficient reduction of NOx emission with saving combustion tuning time.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2413-2422
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• 1994

The effects of compressor design conditions on the off-design performance of a single-shaft gas turbine engine have been studied. Three different geometric design conditions are considered and three different values for the specific mass flow rate at the inlet to the compressor are assumed. For each of nine compressor design, the off-design performance of the gas turbine engine is predicted using the method previously proposed by present authors. Results show that the predicted off-design performances are quite different from each other even though they have the same performance at design point: it means that compressor design conditions should be determined in consideration of the off-design performance of the engine. The specific mass flow rate at the inlet to the compressor is also shown that it might be optimized with respect to the net power of the engine.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.10
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• pp.1361-1369
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• 2003

Design performance of hybrid power generation systems, comprised of a gas turbine and an atmospheric pressure molten carbonate fuel cell, has been analyzed. Two different configurations were analyzed and performances were compared. A reference calculation was performed for the design condition of a system under development and simulated results agreed well with the published data. Performances were analyzed in terms of main design parameters including turbine inlet temperature, operating temperature of the fuel cell and pressure ratio. Also examined were the effects of fuel utilization factor and heat exchanger effectiveness. It was found that the relationship between the turbine inlet temperature and the fuel cell temperature should be critically examined to evaluate achievable design performance. Considering current state of the art technologies, a system with the combustor located before the turbine could achieve higher efficiency and specific power than the other system with the combustor located after the turbine.

• New & Renewable Energy
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• v.6 no.2
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• pp.27-32
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• 2010

Low Calorific Gas Turbine (LCGT) has been developed as a next generation power system using landfill gas (LFG) and biogas made from various organic wastes, food Waste, waste water and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for the optimum applications of LCGT. Main troubles of Low Calorific Gas Turbine system was derived from the impurities such as hydro sulfide, siloxane, water contained in biogas. Even if the quality of the bio fuel is not better than natural gas, LCGT may take low quality gas fuel and environmental friendly power system. The mechanical characterisitics of LCGT system is a high energy efficiency (>70%), wide range of output power (30 kW - 30 MW class) and very clean emission from power system (low NOx). A green house has been designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. LCGT is expected to contribute achieving the target of Renewable Portfolio Standards (RPS).

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3224-3229
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• 2007

This study aims to analyse the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. The steam is generated by recovering heat from the exhaust gas. Two system configurations, with difference being the operating pressure of the SOFC, are examined and effects of steam injection on performances of the two systems are compared. Two representative gas turbine pressure ratios are simulated and a wide range of both the fuel cell temperature and the turbine inlet temperature is examined. Without steam injection, the pressurized system generally exhibits better system efficiency than the ambient pressure system. Steam injection increases system power capacity for all design cases. However, its effect on system efficiency varies much depending on design conditions. The pressurized system hardly takes advantage of the steam injection in terms of the system efficiency. On the other hand, steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. A higher pressure ratio provides a better chance of efficiency increase due to steam injection.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.54-61
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• 2008

Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increases the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.11
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• pp.1013-1021
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• 2000

This paper suggests fuzzy-PI controllers for a heavy-duty gas turbine. The fuzzy-PI controllers are designed to regulate rotor speed and exhaust temperature of the gas turbine. The controller gains are tuned by genetic algorithm(GA). This paper also proposes a new fitness function of GA using a desired output response. The suggested controller is compared with previous controllers via simulations and it is shown that the rotor speed variation of our controller is smaller than those of previous ones.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.191-197
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• 1998

The recent results of the engine development performed in this you on Turbogreen 1200, the first industrial gas turbine engine developed in Korea, are presented. In order to improve the engine performance and structural stability from the first prototype engine, several variants of the engine and major components such as combustor and rotor assembly have been developed and tested. This paper shows these results especially focused on the engine test and performance analysis, in which test system, instrumentation and data processing are discussed as well. The engine performance and its trend give relatively good coincidence with the design ones. At design power of 1.2MW, the thermal efficiency of the engine is estimated over $25\%$ which is below the design target of $27.2\%$. This gap of efficiency is caused mainly by large tip clearance between turbine blades and casing. Considering high design efficiency superior to those of other competitive engines in this power class, Turbogreen 1200 would have a strong competition in its performance if the design efficiency is achieved by further developments such as tip clearance control, which are very possible and natural in final mass production of the developed gas turbine engine.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2409-2420
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• 1996

This paper describes the development of a general program for the design and part load performance analysis of single-shaft-heavy-duty gas turbines. Efforts are made to fully represent the real component features by the characteristic models and special emphasis is put on the modeling of cooled turbine stages. The design analysis routine is applied to simulate the performance of current gas turbines and its appropriateness for system analysis is validated. Meanwhile, the component parameters of real engines which describe the technology level are obtained. The program is extended to predicting the part load operation of gas turbines with the aid of models for the off-design characteristics of compressor, turbine and other main components. Part load simulation can be carried out only with limited numbers of input data. It is demonstrated that the program accurately estimates the part load characteristics of real turbines.

• 연구논문집
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• s.27
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• pp.87-99
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• 1997

Present paper describes on/off design performance of a 50KW turbogenerator gas turbine engine for hybrid vehicle application. For optimum design point selection, relevant parameter study is carried out. The turbogenerator gas turbine engine for a hybrid vehicle is expected to be designed for maximum fuel economy, ultra low emissions, and very low cost. Compressor, combustor, turbine, and permanent-magnet generator will be mounted on a single high speed (82,000 rpm) shaft that will be supported on air bearings. As the generator is built into the shaft, gearbox and other moving parts become unnecessary and thus will increase the system's reliability and reduce the manufacturing cost. The engine has a radial compressor and turbine with design point pressure ratio of 4.0. This pressure ratio was set based on calculation of specific fuel consumption and specific power variation with pressure ratio. For the given turbine inlet temperature, a rather conservative value of $1100^\circK$ was selected. Designed mass flow rate was 0.5 kg/sec. Parametric study of the cycle indicates that specific work and efficiency increase at a given pressure ratio and turbine inlet temperature. Off design analysis shows that the gas turbine system reaches self operating condition at N/$N_{DP}$ = 0.53. Bleeding air for turbine stator cooling is omitted considering low TIT and for a simple geometric structure. Various engine performance simulations including, ambient temperature influence, surging at part load condition. Transient analysis were performed to secure the optimum engine operating characteristics. Surge margin throughout the performance analysis were maintained to be over 80% approximately. Validation of present results are yet to be seen as the performance tests are scheduled by the end of 1998 for comparison.