• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.571-580
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• 2016

In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.6
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• pp.56-65
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• 2008

• Journal of Mechanical Science and Technology
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• v.16 no.6
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• pp.839-850
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• 2002

A performance simulation program for the turboprop engine (PT6A-62), which is the power plant of the first Korean indigenous basic trainer KT-1, was developed for performance prediction, development of an EHMS (Engine Health Monitoring System) and the flight simulator. Characteristics of components including compressors, turbines, power turbines and the constant speed propeller were required for the steady state and transient performance analysis with on and off design point analysis. In most cases, these were substituted for what scaled from similar engine components'characteristics with the scaling law. The developed program was evaluated with the performance data provided by the engine manufacturer and with analysis results of GASTURB program, which is well known for the performance simulation of gas turbines. Performance parameters such as mass flow rate, compressor pressure ratio, fuel flow rate, specific fuel consumption and turbine inlet temperature were discussed to evaluate validity of the developed program at various cases. The first case was the sea level static standard condition and other cases were considered with various altitudes, flight velocities and part loads with the range between idle and 105% rotational speed of the gas generator. In the transient analysis, the Continuity of Mass Flow Method was utilized under the condition that mass stored between components is ignored and the flow compatibility is satisfied, and the Modified Euler Method was used for integration of the surplus torque. The transient performance analysis for various fuel schedules was performed. When the fuel step increase was considered, the overshoot of the turbine inlet temperature occurred. However, in case of ramp increase of the fuel longer than step increase of the fuel, the overshoot of the turbine inlet temperature was effectively reduced.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.76-83
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• 2008

New and more efficient propulsion systems are required for LNG carriers. One of the proposed systems is a combination of a gas turbine with a heat recovery steam generator. This system constitutes a novel approach, which needs to be analyzed by system analysis and risk assessment to compensate for the lack of field experience. Of specific concern is the high pressure fuel supply system. This paper describes the dispersion and fire analysis performed to identify for safety and design improvement of proposed system.

• Proceedings of the KIEE Conference
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• summer
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• pp.752-754
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• 2004

Super high speed motors and generators are increasing in various applications such as air compressor, gas turbine and fuel cell systems because of small size and light weight at the same power level. This paper presents an experiment and simulation for a permanent magnet synchronous motor(PMSM) in super high speed applications.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.331-343
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• 2005

Development of hydrogen station system is an important technology to commercialize fuel cells and fuel cell powered vehicles. Generally, hydrogen station consists of hydrogen production process including desulfurizer, reformer, water gas shift (WGS) reactor and pressure swing adsorption (PSA) apparatus, and post-treatment process including compressor, storage and distributer. In this review, we investigate the R&D trends and prospects of hydrogen station in domestic and foreign countries for opening the hydrogen economy society. Indeed, the reforming of fossil fuels for hydrogen production will be essential technology until the ultimate process that may be water hydrolysis using renewable energy source such as solar energy, wind force etc, will be commercialized in the future. Hence, we also review the research trends on unit technologies such as the desulfurization, reforming reaction of fossil fuels, water gas shift reaction and hydrogen separation for hydrogen station applications.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.1-14
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• 2015

In case of a gas turbine engine for supersonic operation, the engine have a wide range of operating inlet mass flow rate and required high performance such as thrust and fuel consumption. Therefore, variable system and its optimal control logic are essentially needed. In this work, a method for performance prediction of a gas turbine engine with variable system compressor and its control scheme were developed. Conceptual design of compact acuation system for the operation of the variable system was also conducted. The performance of a low-bypass ratio mixed flow turbofan engine was analyzed, and it was observed that the surge margin of the engine is improved at off-design condition by applying the control scheme.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.513-520
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• 2004

A steady-state/transient performance simulation model was newly developed for the propulsion system of the CRW (Canard Rotor Wing) type UAV (Unmanned Aerial Vehicle) during flight mode transition. The CRW type UAV has a new concept RPV (Remotely Piloted Vehicle) which can fly at two flight modes such as the take-off/landing and low speed forward flight mode using the rotary wing driven by engine bypass exhaust gas and the high speed forward flight mode using the stopped wing and main engine thrust. The propulsion system of the CRW type UAV consists of the main engine system and the duct system. The flight vehicle may generally select a proper type and specific engine with acceptable thrust level to meet the flight mission in the propulsion system design phase. In this study, a turbojet engine with one spool was selected by decision of the vehicle system designer, and the duct system is composed of main duct, rotor duct, master valve, rotor tip-jet nozzles, and variable area main nozzle. In order to establish the safe flight mode transition region of the propulsion system, steady-state and transient performance simulation should be needed. Using this simulation model, the optimal fuel flow schedules were obtained to keep the proper surge margin and the turbine inlet temperature limitation through steady-state and transient performance estimation. Furthermore, these analysis results will be used to the control optimization of the propulsion system, later. In the transient performance model, ICV (Inter-Component Volume) model was used. The performance analysis using the developed models was performed at various flight conditions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the turbine inlet temperature overshoot limitation as well as the compressor surge margin. Because the engine performance simulation results without the duct system were well agreed with the engine manufacturer's data and the analysis results using a commercial program, it was confirmed that the validity of the proposed performance model was verified. However, the propulsion system performance model including the duct system will be compared with experimental measuring data, later.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.499-505
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• 2004

A Propulsion System of the CRW(Canard Rotor Wing) type UAV(Unmanned Aerial Vehicle) was composed of the turbojet engine to generate the propulsive exhaust gas, and the duct system including straight bent ducts, tip-jet nozzles, a master valve and a variable main nozzle for three flight modes such as lift/landing mode, low speed transition flight mode and high speed forward flight mode. In this study, in order to operate safely the propulsion system, the dynamic Performance behavior of the system was modeled and simulated using the SIMULIN $K^{ }$, which is the user-friendly GUI type dynamic analysis tool provided by MATLA $B^{ }$. In the transient performance model, the inter-component volume model was used. The performance analysis using the developed models was performed at various flight condition, valve angle positions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the inlet temperature overshoot limitation as well as the compressor surge margin. Performance analysis results using the SIMULIN $K^{ }$ performance program were compared with them using the commercial program GSP.m GSP.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1050-1060
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• 2012

As an approach to high-efficiency of SOFC system, SOFC/GT Hybrid system is effective. However, if the output size of the system belongs to the marine class of dozens MWs, the introduction of the cooling system of GT system, which is used as sub-system, makes its related devices complicated and also makes its control difficult. Accordingly, for the marine use, SOFC/GT (non-cooling)Hybrid system looks more suitable than SOFC/GT(cooling)Hybrid system. This study established the SOFC/GT (non-cooling)Hybrid system, and examined the operating temperature & current density of the stack for the system, pressure ratio of the gas turbine, the influence of TIT(Turbine Inlet Temperature) on system performance, etc. through the simulation process. Through this research process, this study was able to confirm that electrical efficiency rises in spite of the increase in the required power for the air compressor, and there exists a limited range of temperatures for operation in TIT.