• Plant Journal
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• v.4 no.3
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• pp.60-65
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• 2008

Power plant industry has been developed at high-capacity, high-technology, and innovation. Steam turbine became the most useful equipment that dominate more than 50% of all the world electricity production. And developed new materials of the turbine blade and extended length of the turbine last blade brought reform in steam turbine performance upgrade. In this paper, when do partial load driving in high-capacity steam turbine, optimum driving method found whether there is something. In operating steam turbine, there is a lot of loss from secondary wake and throttle of the 1st stage nozzle by the biggest leading factor that load fluctuation affects in high-pressure steam turbine performance. Effect of internal efficiency by 1 stage nozzle is the biggest here, but here fluid flow and flow analysis were not yet examined closely definitely. So, Analyzed design data and acceptance performance test result to applying subcritical pressure drum type 560 MW, supercritical-pressure once through type 500 MW, and 800 MW steam turbines actually. In conclusion, at partial load driving, partial arc admission(PAA) is more efficient than full arc admission(FAA) efficiency. This is judged by because increase being proportional with gross energy of stream that is pressure - available energy if pressure of stream that is flowed in to the turbine increases, available energy becomes maximum and turbine efficiency improves. Therefore, turbine performance is that preview that first stage performance fell if decline is serious in partial load because first stage performance changes according to load.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.8-12
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• 2019

Combined Cycle Unit(CC) generates the primary power from the Gas Turbine(GT) and supplies the remaining heat of the GT to the Steam Turbine(ST) to generate the secondary power from the ST. It plays a major role in terms of energy efficiency and Load Frequency Control(LFC). Incremental Heat Rate(IHR) curves of economic dispatch(ED) of CC is applied differently by GT/ST combination. But It is practically difficult because of performance test by all combinations. This paper suggests a reasonable method for estimating IHR curves for partial combinations(1:1~(N-1):1) using IHR curves when operating with GT alone(1:0) and with all(N:1) combinations of CC.

• Journal of KSNVE
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• v.9 no.3
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• pp.554-564
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• 1999

This paper presents the analytical method to evaluate the seismic responses on steam turbine-generator rotor system. Deterministic analytical methods, such as response spectrum approach, modal superposition method and direct integration method, are used to calculate the seismic response. The computer software is also developed based on the methods then can be applied to estimate the seismic safety of turbine-generator rotor system for power plants. Numerical example of a steam turbine-generator rotor system of 1007MW nuclear power plant is presented. The aseismatic performance are checked by comparing maximum seismic deflection at bearing positions with bearing clearance.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.5
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• pp.586-594
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• 2012

A future type ship power system requires both economic and eco-friendliness. That is, this should be reduced the discharge quantity of air pollutants and green-house gases as well as have high energy efficiency. Recently, gas turbines have been realized a lot of technical development in terms of efficiency and safety, and are widening the example of their adoption to a GT/ST hybrid system in a power plant as well as an aviation use. This paper reviewed the performance characteristics of a GT/ST hybrid system of several ten MW class, not large capacity, with a simulation in order to evaluate the possibility of a GT/ST hybrid system for ships. The reviewed GT/ST hybrid system has maximum 49 % efficiency, has the highest efficiency point for TIT, and has a 70~75 % and 25~30 % load ratio for a gas turbine and a steam turbine respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.161-164
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• 2008

For the development of solar thermal power tower plant from the early 80' to today, various kinds of receiver have been tested and evaluated. Most of 1st generation receiver used water/steam as a working fluid to operate steam turbine and now the first commercial solar power tower PS-10 also makes saturated steam. However, to increase thermal efficiency of storage system and to obtain practical use of solar energy, molten salt system have been used from THEMIS project in France at 1984. The Solar Tres plant of 17 MWe power generation will be constructed in Spain and have plan to operate 24 hours in summer. The air volumetric receiver system can be integrated with combined cycle of gas turbine and HRSG and also with steam turbine easily. Therefore, related researches to develop higher efficient solar power tower plant and to operate with stable are widely performed in the world.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.590-599
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• 2011

The electrification of the waste heat of fuel cell is necessary to enhance the efficiency of fuel cell system. For this purpose, the SOFC/ST(Solid oxide fuel cell/Steam turbine) hybrid system is suitable. The purpose of this work is to predict the performance of methane fueled SOFC/ST hybrid power system and to analyze the influence of operating temperature of stack, current density of stack, combustor outlet gas temperature, and boiler outlet gas temperature. According to the analysis, it is proved that making the best use of the waste heat of stack and minimizing the fuel consumption of combustor are essential for the high-efficiency of SOFC/ST hybrid system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.470-476
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• 2002

We tested the natural frequency for the 1st moving blades of a steam turbine in general power plants, carried out the modal test of the blade groups each natural frequency. By this test results, we identified the resonance results largely in damaging the blades. We can predict damage probability for the blade groups and change state of material property by using the result of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3353-3359
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• 2011

The co-generation system consisted of gas a turbine, a steam turbine, heat recovery steam generator and a heat exchangers for district heating was investigated in the present study. A back-pressure steam turbine (non-condensing type) was used. A partial load analysis according to the outdoor temperature in winter was conducted and optimal thermal load and power conditions was examined using the commercial computing software Thermoflex. As a result, under a constant thermal load, the power outputs of gas turbine and overall system increased as an outdoor temperature decreased. On the other hand, the reduction in exhaust gas temperature led to the decrease in output of steam turbine. Considering the portion of gas turbine in overall system in terms of the power output, it can be known that the tendency in power output of overall system was similar to that of the gas turbine.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.5
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• pp.380-388
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• 2002

This paper describes the optimum design for low-pressure steam turbine rotor of 1,000 MW nuclear power plant by using a combined genetic algorithm, which uses both a genetic algorithm and a local concentrate search algorithm (e.g. simplex method). This algorithm is not only faster than the standard genetic algorithm but also supplies a more accurate solution. In addition, this algorithm can find the global and local optimum solutions. The objective is to minimize the resonance response (Q factor) and total weight of the shaft, and to separate the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraint. In the present work, the shaft diameter, the bearing length, and clearance are used as the design variables. The results show that the proposed algorithm can improve the Q factor and reduce the weight of the shaft and the 1st critical speed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.52-57
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• 2018

Most current ships have adopted on-board diesel generators to produce electricity, but the overall efficiency of equipment is down to about 50% due to thermal losses from operations such as exhaust gas, jacket water cooler, scavenge air cooler, etc. Recently, fuel cells have been highlighted as a promising technology to reduce the effect on the environment and have a higher efficiency. Therefore, this paper suggested a solid oxide fuel cell (SOFC)-gas turbine (GT) using waste heat from a SOFC and SOFC-GT-steam turbine (ST) with Rankine cycle. To compare both configurations, the fuel flow rate, current density, cell voltage, electrical power, and overall efficiency were evaluated at different operating loads. The overall efficiency of both SOFC hybrid systems was higher than the conventional system.