• Journal of Energy Engineering
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• v.2 no.1
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• pp.83-94
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• 1993

In this paper, the performance of an energy conversion system is analyzed using two efficiency concepts, one of conventional and the other of energetic efficiently. The objective of this analysis was to improve and optimize the energy conversion system in point, namely, and LNG-fired Combined Heat and Power Plant (CHP). To this end, energies which represent the true efficiency figures were evaluated for various flows of the system with a set of system configurations given. Then the economic values of the energies were assigned to respective flows and subsystems. With these economic data locations of inefficiencies and opportunities for improvement are identified.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.77-78
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• 2023

This paper experimentally examined the recycling of combustion by-products emitted from a combined heat and power plant using lignocellulosic biomass fuel. Physical and chemical analyzes were performed on Bio-SRF and three types of wood pellet combustion by-product samples (fly-ash, FA). As a result of the experiment, the compressive strength of mortar substituted with 5, 10, and 20% of FA compared to the cement weight was found to be excellent, and its recyclability was confirmed as a substitute for existing admixtures.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.358-364
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• 2018

In this study, the theoretical methodology is presented for estimating cost function based on operating modes for Combined Cycle Power Plant. The proposed method has estimated cost functions using the relationship between the gas turbine heat input and the output ratio of the steam turbine. In order to verify the proposed method, a regression analysis was performed using the single cost function estimated by the existing performance test method and the cost function for each operating mode estimated by the proposed method. The results of case studies using the 2016 generator input and output data are presented to show the effectiveness of the proposed method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.994-1001
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• 2000

The dynamic behavior of a single-pressure heat recovery steam generator and turbine system for the combined cycle power plant is simulated on the basis of one-dimensional unsteady governing equations. A water level control and a turbine power control are also included in the calculation routine. Transient response of the system to the variation of gas turbine exit condition is simulated and effect of the turbine power control on the system response is examined. In addition, the effect of the treatment of inertia terms(fluid inertia and thermal inertia of heat exchanger metal) on the simulated transient response is investigated.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.2
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• pp.103-111
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• 2019

The combined cycle plant is an integration of gas turbine and steam turbine, combining the advantages of both cycles. It recovers the heat energy from gas turbine exhaust to use it to generate steam. The heat recovery steam generator plays a crucial role in combined cycle plants, providing the link between the gas turbine and the steam turbine. Simulation of the performance of the HRSG is required to study its effect on the entire cycle and system. Computational fluid dynamics has potential to become a useful to validate the performance of the HRSG. In this study a solver has been implemented in the open source code, OpenFOAM, for combustion simulation in the heat recovery steam generator. The solver is based on the steady laminar flamelet model to simulate detailed chemical reaction mechanism. Thereafter, the solver is used for simulation of HRSG system. Three cases with varying fuel injections and gas turbine exhaust gas flow rates were simulated and the results were compared with measurements at the system outlet. Predicted temperature and emissions and those from measurements showed the same trend and in quantitative agreement.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.177-182
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• 2009

The purpose of this study is to investigate planning of urban energy supply systems configuration and operating conditions for the district heating and cooling system using combined heat and power system. Generally the district heating and cooling system has been known to one of the effective way for energy saving, cost reduction and demand side management of energy. Economical analyses were carried out and operating characteristics for some systems were examined in terms of GER factor which represents to the ratio of gas and electricity costs. Rates of the energy consumption and the $CO_2$ emission were compared from the system configuration of the energy supply system with new district cooling system with the conventional one.

• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.309-318
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• 2024

This research investigated the feasibility of incorporating industrial by-products into precast concrete formulated with blast furnace slag and natural gypsum. Specifically, the study examined the effects of incorporating steelmaking slag(STS slag), combined heat power plant fly ash, and return dust. The optimal amount of these by-products was determined by measuring air content, slump, and compressive strength at various incorporation levels. Results demonstrated that compressive strength was enhanced across all levels of by-product addition. Notably, incorporating 10% of the by-products led to exceptional early-age strength development. However, a 20% addition of combined heat power plant ash significantly reduced the slump value by approximately 40%. Considering these findings and the requirement for rapid strength development in precast concrete applications, a 10% incorporation of industrial by-products was deemed optimal due to its ability to accelerate early-age strength gain.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.148-151
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• 2004

The hardening of concrete after setting is accompanied with nonlinear temperature distribution caused by development of hydration heat of cement. Especially at early ages, this nonlinear distribution has a large influence on the tensile cracking. As a result, in order to predict the exact temperature distribution in concrete structures it is required to examine thermal properties of concrete. In this study, the coefficient of air convection for concrete mix of nuclear power plant, which presents thermal transfer between surface of concrete and air, was experimentally investigated with variables such as velocity of wind and types of form. The coefficient of air convection obtained from experiment increases with velocity of wind, and its dependance on wind velocity is varied with types of form. This tendency is due to a combined heat transfer system of conduction through form and convection to air. The coefficient of air convection for concrete mix of nuclear power plant obtained from this study was well agreed with the existing models.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.162-163
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• 2022

Maritime transportation is going to transfer to alternative fuels as a result of the worldwide demands toward decarbonization and tougher maritime emissions regulations. Methanol is considered as a potential marine fuel, which has the ability to reduce SOx and CO₂ emissions, reduce climate change effects, and achieve the objective of green shipping. This work proposes and combines the innovative combination system of direct methanol solid oxide fuel cells (SOFC), proton exchange membrane fuel cells (PEMFC), gas turbines (GT), and organic Rankine cycles (ORC) for maritime vessels. The system's primary power source is the SOFC, while the GT and PEMFC use the waste heat from the SOFC to generate useful power and improve the system's ability to use waste heat. Each component's thermodynamics model and the combined system's model are established and examined. The multigeneration system's energy and exergy efficiency are 76.2% and 30.3%, respectively. When compared to a SOFC stand-alone system, the energy efficiency of the GT and PEMFC system is increased by 19.2%. The use of PEMFC linked SOFC has significant efficiency when a ship is being started or maneuvered and a quick response from the power and propulsion plant is required.