• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.10
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• pp.1370-1377
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• 2002

This study analyzed the design performance of the bottoming system of combined cycle power plants using a once-through heat recovery steam generator. For a parallel arrangement of the main heater and reheater, parametric analyses were carried out to present the criteria for determining the reheater pressure and the location of the starting point of the reheater in the HRSG. The performance of the bottoming system was presented fer a range from high subcritical to supercritical pressure. The steam turbine power is as high as that of conventional triple-pressure bottoming systems. The serial arrangement of heat exchangers with division of each heater into several segments can achieve similar power level.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.872-877
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• 2001

This study analyzed the design performance of the bottoming system of combined cycle power plants adopting a single-pressure once-through heat recovery steam generator with reheat. A computer program was constructed and parametric analyses were carried out to present the criteria for determining the reheat pressure and the location of the starring point of the reheater in the HRSG. The performance of the bottoming system was presented for the range from high subcritical to supercritical pressures. It was founded that the power of the bottoming system can be as high as that of the present triple-pressure bottoming system even with a higher exhaust gas temperature. A requirement for this high performance is a proper arrangement of the reheater.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.782-787
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• 2001

An optimum thermal design analysis of the combined cycle power plant with triple pressure heat recovery steam generator was performed by the numerical simulation. The optimum design module used in the paper is DNCONF, a function of IMSL Library, which is widly known as a method to search for the local optimum. The objective function to be minimized is the cost of total power plant including the steam turbine power enhancement premium. The result of this paper shows that the cost reduces if the design point of power plant becomes the local optimum, and many calculations at various initial conditions should be carried out to get the value near the global optimum.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3236-3240
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• 2007

This paper describes the results of steam turbine performance tests. The objectives of performance test is to exactly evaluate the degradation(decrease in performance) of the coal-fired steam turbine generator in order to provide plant information to help performance engineers identify problems, improve performance, and make economic decisions about scheduling maintenance and optimizing operation. To achieve these goals, the periodic thermal performance tests have been carried out since the initial operation period, 1997. We made the calculation program and guidelines for the tests and developed the performance index of the turbine cycle on the basis of the ASME PTC. By comparing the performance changes throughout the whole operation period, we confirmed the performance reliabilities of the turbine and its conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.74-82
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• 1998

Combined cycle power plant is a system where a gas turbine or a steam turbine is used to produce shaft power to drive a generator for producing electrical power and the steam from the HRSG is expanded in a steam turbine for additional shaft power. The temperature of the exhaust gases from a gas turbine ranges from $400{\sim}650^{\circ}C$, and can be used effectively in a heat recovery steam generator to produce steam. Combined cycle can be classed as a topping and bottoming cycle. The first cycle, to which most of the heat is supplied, is a Brayton gas turbine cycle. The wasted heat it produces is then utilized in a second process which operates at a lower temperature level is a steam turbine cycle. The combined gas and steam turbine power plant have been widely accepted because, first, each separate system has already proven themselves in power plants as an independent cycle, therefore, the development costs are low. Secondly, using the air as a working medium, the operation is relatively non- problematic and inexpensive and can be used in gas turbines at an elevated temperature level over $1000^{\circ}C$. The steam process uses water, which is likewise inexpensive and widely available, but better suited for the medium and low temperature ranges. It therefore, is quite reasonable to use the steam process for the bottoming cycle. Recently gas turbine attained inlet temperature that make it possible to design a highly efficient combined cycle. In the present study, performance analysis of a 3 pressured combined cycle power plant is carried out to investigate the influence of topping cycle to combined cycle performance. Present calculation is compared with acceptance performance test data from SeoInchon combined cycle power plant. Present results is expected to shed some light to design and manufacture 150~200MW class heavy duty gas turbine whose conceptual design is already being undertaken.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.452-455
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• 2005

We have studied the prearranged plan and the economy of a candidate site for the development of small hydro power. And also we have confirmed its economy by suggesting the technology of the unmanned operation and the selection of the water turbine generator which has a great efficiency. working rate and suitability to the topographical characteristics of various development sites, for example, irrigation reservoirs, water works pipes, sewage systems and cool ing water of a steam power stat ion. Besides we give more examples of the select ion of Francis, propeller turbine and induction generator which can achieve a maximum of power production at a minimum construction cost. With a water turbine which runs at the low head we are able to suggest many programs to boost a development of small hydro power more economically.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.409-413
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• 2016

The 500 MW rated steam turbine model in coal fired power plant is developed to be used for validation and verification of controller rather than for the education of operator. The valve, steam turbine, reheater and generator are modeled and integrated into the simulator. And the data from the plant heat balance diagram are used for estimation of the model parameters together with actual operating data. It is found that the outputs of model such as pressure, temperature and speed are similar to the operating ones. So, it is expected that the developed model will play a very big role in controller development.

• Journal of Power System Engineering
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• v.14 no.4
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• pp.43-49
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• 2010

In the present study, optimization of throttle margin for high pressure turbine to be retrofitted or partially modified for power uprating or life extension in nuclear power plant, has been performed to increase the electrical output. Throttle margin for high pressure turbine is required to maintain all the time the rated power by opening more of governor valves whenever inlet pressure is decreased due to the tube plugging of steam generator. If throttle margin of high pressure turbine is too much compared to remaining lifetime, loss of electrical output due to pressure drop of governor valves is inevitable. On the contrary, if it is too little, the rated power operation can not be accomplished when inlet pressure of high pressure turbine is dropped after many years operation. So, throttle margin for high pressure turbine in nuclear power plant is compromised considering for the degradation of steam generator, governor valve capacity, manufacturing tolerance of high pressure turbine, future plan of power uprating, and remaining lifetime of power plant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1066-1071
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• 2007

This case study refers to turbine-generator with retrofitted turbine rotor. Vibration problem occurring after the retrofit was mainly due to high vibration from exciter side. However, repeated test run and operation during scheduled maintenance caused high vibration from generator bearing, and post-overhaul test run before turbine vibration correction caused oil whip on the bearing. This case study shows how to analyze vibration condition of high turbine generator vibration detected during the post-overhaul test run and vibration condition of offline and online data to reflect it on establishing maintenance schedule and overhaul correction procedure. Vibration data could be acquired during steady load operation or even with varying speed and load. Each data is important for machinery condition evaluation. This case study shows that the vibration data during extreme condition is the key factor in analysis, which helps to find the machinery problem.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.238-246
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• 2008

This case study refers to turbine-generator with retrofitted turbine rotor. Vibration problem occurring after the retrofit was mainly due to high vibration from exciter side. However, repeated test run and operation during scheduled maintenance caused high vibration from generator bearing, and post-overhaul test run before turbine vibration correction caused oil whip on the bearing. This case study shows how to analyze vibration condition of high turbine generator vibration detected during the post-overhaul test run and vibration condition of offline and online data to reflect it on establishing maintenance schedule and overhaul correction procedure. Vibration data could be acquired during steady load operation or even with varying speed and load. Each data is important for machinery condition evaluation. This case study shows that the vibration data during extreme condition is the key factor in analysis, which helps to find the machinery problem.