• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.276-282
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• 1996

This study dealt with the properties for fly ash of combined heat power plant and application for concrete industry. For this purpose, fly ash of ulsan combined heat power plant was analyzed for physical and chemical properties and tested the properties of the super flowing concrete. As results of fly ash, contents of SiO2 and Al2O3 in the fly ash of Ulsan were less than those of thermal power plant(Boryung), but contents of CaO were ten times as much as those of Boryung. In order to satisfy the properties of the Super Flowing Concrete using class C fly ash, mixing conditions were determined the optimum water-binder(w/b), volume ratio of fine aggregates(Sr) and coarse aggregates(Gv).

• JOURNAL OF ELECTRICAL WORLD
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• s.335
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• pp.22-27
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• 2004

Microturbine geneator is the system generating electric power under 300kW using a gas turbine, and the combined heat and power generating system is recycling exhausted gas to increase thermal efficiency. Microturbine system is featured as small, efficient

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.3
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• pp.507-514
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• 2002

A computation routine, capable of performing thermal design analysis of the triple-pressure bottoming system (heat recovery steam generator and steam turbine) of combined cycle power plants, is developed. It is based on thermal analysis of the heat recovery steam generator and estimation of its size and steam turbine power. It can be applied to various parametric analyses including optimized design calculation. This paper presents analysis results for the effects on the design performance of heat exchanger arrangements at intermediate and high temperature parts as well as steam pressures. Also examined is the effect of steam sources for deaeration on design performance.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.1
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• pp.34-45
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• 2007

In order to reduce the compression power and to use the overall energy contained in LNG effectively, a combined cycle is devised and simulated. The combined cycle is composed of two cycles; one is an open cycle of liquid/solid carbon dioxide production cycle utilizing LNG cold energy in $CO_2$ condenser and the other is a closed cycle gas turbine which supplies power to the $CO_2$ cycle, utilizes LNG cold energy for lowering the compressor inlet temperature, and uses the heating value of LNG at the burner. The power consumed for the $CO_2$ cycle is investigated in terms of a solid $CO_2$ production ratio. The present study shows that much reduction in both $CO_2$ compression power (only 35% of the power used in conventional dry ice production cycle) and $CO_2$ condenser pressure could be achieved by utilizing LNG cold energy and that high cycle efficiency (55.3% at maximum power condition) in the gas turbine could be accomplished with the adoption of compressor inlet cooling and regenerator. Exergy analysis shows that irreversibility in the combined cycle increases linearly as a solid $CO_2$ production ratio increases and most of the irreversibility occurs in the condenser and the heat exchanger for compressor inlet cooling. Hence, incoming LNG cold energy to the above components should be used more effectively.

• Journal of Energy Engineering
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• v.28 no.2
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• pp.47-54
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• 2019

As absorption type heat pump for waste heat recovery is installed in combined cycle power plant for Energy Service Company, performance test is implemented to confirm the operation data on partial load. The operation data changes according to the heat pump operation on partial load are as follows. Total heat output increases, because waste heat of closed cooling water and a portion of LP steam from HRSG is supplied. But electric power output of steam turbine is reduced, because LP steam to steam turbine is reduced. And heat output from HP district heater and LP district heater is reduced, because HP turbine exhaust steam to HP district heater and LP district heater is reduced. On partial load operation, turbine output reduction is higher than the base load operation. Therefore, on partial load, heat pump should be operated in consideration of the heat output increase and electric power output reduction.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.129-135
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• 1997

Recently, discarding of reuse of fly ashes produced from combined heat power plant of thermal power plant as a by-product causes several problems. Esepecially, the fly ash from Ulsan Pertrochemical Serviec Co, classified as class C is the first by-product to be reused or discarded. For the reuse of the class C fly ash, it is necessary to prepare and provide domestic specifications because there is no specifications on the fly ash of class C from combined heat power plant. Therefore, this study dealt with a scheme of introducing class C fly ash to the korean industrial standard.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.49-51
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• 2012

In this paper, the integration issue, such as an air-side integration design between the gas turbine and air separation unit, is described and analyzed by the exergy and energy balance of the combined-cycle power block in an IGCC power plant. The results showed that the net power of the system was almost same, but that of the gas turbine was decreased as the integration degree increased. The highest exergy loss was occurred in the combustor of gas turbine, which was affected by the chemical reaction, heat conduction, mass diffusion, and viscous dissipation.

• 열병합발전
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• s.66
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• pp.4-7
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• 2008

When a Combined cycle power plant was started, Steam turbine wasted pure water too much during prewarming of turbine. Wasted pure water gathered in vessel tank and evaporated immediately, then emitted atmosphere. We investigate method to recover the heat in vessel tank. We installed a heat exchanger in vessel tank. In this study, the designing and manufacturing procedures of the heat exchanger was presented. Also, the performance results was showed briefly.

• Journal of Power System Engineering
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• v.12 no.4
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• pp.57-63
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• 2008

The last stage blade of the low pressure steam turbine remarkably affects turbine plant performance and availability Turbine manufacturers are continuously developing the low pressure last stage blades using the latest technology in order to achieve higher reliability and improved efficiency. They tend to lengthen the last stage blade and apply shrouds at the blades to enhance turbine efficiency. The long blades increase the blade tip circumferential speed and water droplet erosion at shroud is anticipated. Parts of integral shrouds of the last stage 40 inch blades were cracked and liberated recently in a combined cycle power plant. In order to analyze the root cause of the last stage blades shroud cracks, we investigated operational history, heat balance diagram, damaged blades shape, fractured surface of damaged blades, microstructure examination and design data, etc. Root causes were analyzed as the improper material and design of the blade. Notches induced by erosion and blade shroud were failed eventually by high cycle fatigue. This paper describes the root cause analysis and countermeasures for the steam turbine last stage blade shroud cracks of the combined cycle power plant.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.234-241
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• 2020

This paper presents a thermodynamic performance analysis of a combined cycle consisting of regenerative organic Rankine cycle (ORC) and liquefied natural gas (LNG) Rankine cycle to recover low-grade heat source and the cold energy of LNG. The mathematical models are developed and the system performances are analyzed in the aspect of thermodynamics. The effects of the turbine inlet pressure and the working fluid on the system performance such as the mass flow rates, heat transfers at heat exchangers, power productions at turbines, and thermal efficiency are systematically investigated. The results show that the thermodynamic performance of ORC such as net power production and thermal efficiency can be significantly improved by the regenerative ORC and the LNG cold energy.