• Journal of Mechanical Science and Technology
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• 제20권9호
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• pp.1502-1513
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• 2006

This study analyzes the design and part load performance of a power generation system combining a micro gas turbine (MGT) and an organic Rankine cycle (ORC). Design performances of cycles adopting several different organic fluids are analyzed and compared with performance of the steam based cycle. All of the organic fluids recover greater MGT exhaust heat than the steam cycle (much lower stack temperature), but their bottoming cycle efficiencies are lower. R123 provides higher combined cycle efficiency than steam does. The efficiencies of the combined cycle with organic fluids are maximized when the turbine exhaust heat of the MGT is fully recovered at the MGT recuperator, whereas the efficiency of the combined cycle with steam shows an almost reverse trend. Since organic fluids have much higher density than steam, they allow more compact systems. The efficiency of the combined cycle, based on a MGT with 30 percent efficiency, can reach almost 40 percent. hlso, the part load operation of the combined system is analyzed. Two representative power control methods are considered and their performances are compared. The variable speed control of the MGT exhibits far better combined cycle part load efficiency than the fuel only control despite slightly lower bottoming cycle performance.

• 한국유체기계학회 논문집
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• 제6권3호
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• pp.28-35
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• 2003

This paper presents analysis results for the effect of power control strategies on the part load performance of gas turbine based power generation systems utilizing exhaust heat of the gas turbine such as combined cycle power plants and regenerative gas turbines. For the combined cycle, part load efficiency variations were compared among different single shaft gas turbines representing various technology levels. Power control strategies considered were fuel only control and IGV control. It has been observed that gas turbines with higher design performances exhibit superior part load performances. Improvement of part load efficiency of the combined cycle by adopting air flow modulation was analyzed and it was concluded that since the average combined cycle performance is affected by the range of IGV control as well as its temperature control principle, a control strategy appropriate for the load characteristics of the individual plant should be adopted. For the regenerative gas turbine, it is likewise concluded that maintaining exhaust temperature as high as possible by air flow rate modulation is required to increase part load efficiency.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.167-170
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• 2008

아음속과 초음속 영역에서 모두 비행하는 재사용 비행체의 추진기관인 TBCC(Turbine Based Combined Cycle)엔진의 성능 설계 기법에 대한 연구를 수행하였다. 이 엔진은 터보제트엔진과 램제트 엔진의 복합 사이클 엔진으로 구성되어 있으며, 비행 마하수 영역별로 터보제트엔진의 작동과 램제트 엔진의 작동 그리고 터보제트엔진과 램제트엔진이 동시 작동하는 구간으로 구성된다. TBCC엔진의 성능해석 기법을 제안하고, 개별 엔진의 성능 결과를 검증 하였으며, 가상의 비행 영역에서 TBCC엔진의 성능을 해석하였다.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1582-1590
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• 2004

The purpose of this study is to show the existence of optimal operation conditions for minimum fuel consumption of the gas turbine based combined cycle cogeneration power plant. Optimal operational condition means the optimal distribution of the power generated by each gas turbine and the heat generated by each HRSG. Total fuel consumption is calculated by the sum of the fuels for gas turbines and supplementary boiler. Fuel consumption is calculated by numerical methods of energy equations which contain the power generated from gas and steam turbines, the heat generated by HRSG and the heat extracted from high pressure steam turbine.

• 대한기계학회논문집B
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• 제30권5호
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• pp.472-479
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• 2006

Recently, various methods have been developed to improve the performance of gas turbines for combined cycle power plants. This paper especially focused on the gas turbine with a reheat process. The purpose of this study is to analyze performance characteristics of a reheat-cycle gas turbine on both a design point and off-design operations. Results of the parametric study of this model show how operating and design parameters influence on the performance of the gas turbine. Moreover, possibilities for the analysis of off-design performance based on a self-generated compressor performance characteristic map are presented.

• 설비공학논문집
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• 제17권6호
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• pp.536-543
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• 2005

This study analyzes the design performance of a combined system of a recuperated cycle micro gas turbine (MGT) and a bottoming organic Rankine cycle (ORC) adopting refrigerant (R123) as a working fluid. In contrast to the steam bottoming Rankine cycle, the ORC optimizes the combined system efficiency at a higher evaporating pressure. The ORC recovers much greater MGT exhaust heat than the steam Rankine cycle (much lower stack temperature), resulting in a greater bottoming cycle power and thus a higher combined system efficiency. The optimum MGT pressure ratio of the combined system is very close to the optimum pressure ratio of the MGT itself. The ORC's power amounts to about $25\%$ of MGT power. For the MGT turbine inlet temperature of $950^{\circ}C$ or higher, the combined system efficiency, based on shaft power, can be higher than $45\%$.

• 한국유체기계학회 논문집
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• 제9권6호
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• pp.35-44
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• 2006

Operation conditions of a reheat cycle gas turbine for a combined cycle power plant was analyzed. Based on measured performance parameters of the gas turbine, a performance analysis program predicted component characteristic parameters such as compressor air flow, compressor efficiency, efficiencies of both the high and low pressure turbines, and coolant flows. The predicted air flow and its variation with the inlet guide vane setting were sufficiently accurate. The compressor running characteristic in terms of the relations between air flow, pressure ratio and efficiency was presented. The variations of the efficiencies of both the high and low pressure turbines were also presented. Almost constant flow functions of both turbines were predicted. The current methodology and obtained data can be utilized for performance diagnosis.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.290-297
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• 2002

This paper presents analysis results for the effect of power control strategies on the part load performance of gas turbine based power generation systems utilizing exhaust heat of the gas turbine such as cumbined cycle power plants and regenerative gas turbines. For the combined cycle, part load efficiency variations were compared among different single shaft gas turbines representing various technology levels. Power control strategies considered were fuel only control and IGV control. It has been observed that gas turbines with higher design performances exhibit superior part load performances. Improvement of part load efficiency by adopting air flow modulation was analyzed and it is concluded that since the average combined cycle performance is affected by the range of IGV control as well as its temperature control principle, a control strategy appropriate for the load characteristics of the individual plant should be adopted. For the regenerative gas turbine, it is likewise concluded that maintaining exhaust temperature as high as possible by air flow rate modulation is required to increase part load efficiency.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.415-419
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• 2016

As the need for clean coal technology has grown, so has the global research and development efforts into integrated gasification combined cycle (IGCC) plants. An IGCC plant couples a gas turbine to a gasification block. Various technical and economic problems exist in designing such a system. One such problem is the difficulty in realizing economies of scale because the single-train flow capacity of commercial IGCC synthetic gas turbine plants is limited; the capacity does not exceed a net power rating of 300 MW. To address this problem, this study modeled and simulated a synthetic gas turbine with the goal of evaluating the feasibility of a 500 MW or larger IGCC plant. First, a gas turbine with the best output and efficiency was chosen for use with natural gas. The turbine was modeled using GateCycle (a simulation tool), and the integrity of the model validated by comparing the result to the design value. Next, off-design modeling was carried out for a gas turbine with synthetic gas based on its on-design model, and the result was compared with the study result of the gas turbine manufacturer. The simulation confirmed that it is possible to create a large capacity IGCC plant by undertaking the remodeling of a gas turbine designed to use natural gas into one suitable for synthetic gas.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.738-743
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• 2001

A computer program, capable of performing thermal design analysis of the triple pressure bottoming system of combined cycle power plants, was developed. The program is based on thermal analysis of the heat recovery steam generator and estimation of its size and steam turbine power. The program is applicable to various parametric analyses including optimized design calculation. This paper presents examples of analysis results for the effects of arrangement of heat exchanger units, steam pressures and deaerating sources on design performance indices such as steam turbine power and the size of heat recovery steam generator.