• New & Renewable Energy
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• v.7 no.2
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• pp.10-17
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• 2011

Korea is the 11th largest energy consumption country and 96% of its total energy consumption depends on imports from overseas. Therefore it is a very important task to secure renewable energy sources which can reduce both the carbon-dioxide emission and dependency on overseas energy imports. Among the various renewable energy sources, organic wastes are important sources. In Korea, 113 million toe of methane is generated from organic wastes annually, but only 3.7% is effectively used for energy conversion. Thus, it is very important to make better use of organic wastes, especially for power generation. The goals of this project are to develope the fuel supplying system of Bio Gasturbine (GT) for 5MW-class co-generation system. The fuel supplying system mainly consists of $H_2S$ removal system, Bio Gas compression system, Siloxane removal system and moisture separating systems. The fuel requirement of 5MW-class GT is at around 60% of $CH_4$, $H_2S$ (<30 ppm), Siloxane(<10 mg/$nm^3$) and supply pressure (> 25 bar) from biogas compressor. Main mechnical charateristics of Bio Gasturbine system have the specific performance; 1) high speed turbine speed (12,840 rpm) 2) very clean emmission NOx (<50 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for food waste biogas pretreatment system for 5MW-class biogas turbine. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of bioenergy, this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1013-1020
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• 2004

The hybrid system of gas turbine and fuel cell is expected to produce electricity more efficiently than conventional methods, especially in small power applications such as distributed generation. The solid oxide fuel cell (SOFC) is currently the most promising fuel cell for the hybrid system. To realize the conceptual advantages resulting from the hybridization of gas turbine and fuel cell, optimized construction of the whole system must be the most important. In this study, parametric design analyses for pressurized GT/SOFC systems have been peformed considering probable practical limiting design factors such as turbine inlet temperature, fuel cell operating temperature, temperature rise in the fuel cell and soon. Analyzed systems include various configurations depending on fuel reforming type and fuel supply method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.5
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• pp.448-456
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• 2007

Performance of PEM fuel cell systems and hybrid systems combining a PEMFC with a gas turbine have been evaluated. Two different reforming methods(steam reforming and autothermal reforming) were considered. Performances of fuel cell systems with two reforming methods were compared and effects of various design parameters on the system performance were investigated. Configurations of PEM fuel cell systems with two reforming methods have been revised to accommodate a gas turbine, resulting in PEMFC/GT hybrid systems. Performance of the hybrid systems were analyzed and compared with those of PEM systems. Influences of major design parameters on the hybrid system performance were also investigated.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1040-1049
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• 2010

The strengthened regulations for atmospheric emissions from ships have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. Recently, new kinds of propulsion power system such as fuel cell system, which use hydrogen as an energy source, have been sincerely considered. The purpose of this work is to predict the performance of methanol fueled SOFC/GT hybrid power system and to analyze the influence of operating temperature of stack, current density of stack, pressure ratio of turbine, temperature effectiveness of recuperator, turbine inlet temperature.

• The KSFM Journal of Fluid Machinery
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• v.11 no.4
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• pp.52-62
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• 2008

All forecasts of a future energy demand anticipate an increase across the globe. With the increase of energy demand, the emission of $CO_2$ is also likely to increase by at least the same amount because energy supply will be based on fossil fuels, which is more apparent in a number of developing countries. In this context, the Micro Gas Turbine (MGT) is being considered as a promising solution. In order to propose a feasible concept of those technologies such as improving environmental effect and economics, we performed a sensitivity study for a biomass fueled MGT using a simulation model. The study consists of 1) the fundamental modeling using manufacturer's technical specifications, 2) the correction with the experimental data, and 3) the sensitivity study for system parameters. The simulation model was developed by PEPSE-GT 72, commercial steam/gas turbine simulation toolbox.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.11
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• pp.849-855
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• 2008

The paper addresses modeling and analysis of the part load performance of a hybrid fuel cell system integrating a polymer electrolyte membrane fuel cell(PEMFC) and a gas turbine(GT). The system is a pressurized one where the working pressure of the PEMFC is higher than the ambient pressure. In addition to the two major components, the system also includes auxiliary parts such as a steam reformer, a humidifier, and afterburner and so on. Based on design analysis, component off-design models are incorporated in the analysis program and part load operation is simulated. The mode for the part load operation of the PEMFC/GT hybrid system is a variable rotational speed operation. The operating characteristics and variations in the system efficiency and component performance parameters at part load are analyzed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.3 s.246
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• pp.193-200
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• 2006

The purpose of this study is to compare the part-load performance of a SOFC/GT hybrid power system with three different kinds of load-following operation modes. The primary mode for the part load operation of a hybrid power system is the reduction of supplied fuel (e.g., fuel control mode) to the hybrid system. The other two options, i.e., variable speed and VIGV controls, are related to the reduction of supplied air simultaneously with the reduction of supplied fuel to the system. With the performance analysis of a SOFC/GT hybrid power system, it is concluded that the variable speed con佐ol mode Provides the best performance for the part-load operations. It is also found that the VIGV control mode, with its better performance behavior than the fuel control mode, can be used as an important option for the part-load operation especially in case that the variable speed control mode can not be adopted.

• Advances in Energy Research
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• v.3 no.3
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• pp.167-179
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• 2015

This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.125-136
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• 2024

This research presents an innovative integrated ethanol solid oxide fuel cell (SOFC) system designed for applications in marine vessels. The system incorporates an exhaust gas heat recovery mechanism. The high-temperature exhaust gas produced by the SOFC is efficiently recovered through a sequential process involving a gas turbine (GT), a regenerative system, steam Rankine cycles, and a waste heat boiler (WHB). A comprehensive thermodynamic analysis of this integrated SOFC-GT-SRC-WHB system was performed. A simulation of this proposed system was conducted using Aspen Hysys V12.1, and a genetic algorithm was employed to optimize the system parameters. Thermodynamic equations based on the first and second laws of thermodynamics were utilized to assess the system's performance. Additionally, the exergy destruction within the crucial system components was examined. The system is projected to achieve an energy efficiency of 58.44% and an exergy efficiency of 29.43%. Notably, the integrated high-temperature exhaust gas recovery systems contribute significantly, generating 1129.1 kW, which accounts for 22.9% of the total power generated. Furthermore, the waste heat boiler was designed to produce 900.8 kg/h of superheated vapor at 170 ℃ and 405 kP a, serving various onboard ship purposes, such as heating fuel oil and accommodations for seafarers and equipment.

• Plant Journal
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• v.9 no.4
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• pp.31-36
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• 2013

In order to extend a hot gas parts replacement cycle of a gas turbine, blade row 1 from low pressure turbine, which has a significant impact on the cycle, has been selected from stored set after one cycle use. Taking into account the status of the first stage moving blade in LP turbine operated more than 27,000 equivalent operating hours(EOH) and the replacement cycle in the same type of gas turbine, the replacement of the high temperature components installed on the GT, a study subject, can be extended from 24,000 to 27,000 EOH.