• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.12
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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.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.327-334
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• 2022

In this study, in order to evaluate the characteristics of mortar and concrete using wood chip cogeneration plant flooring as fine aggregate, mortar characteristics according to wood chip aggregate replacement rate and water-cement ratio as a substitute for crushed sand, and concrete characteristics according to wood chip aggregate replacement rate were compared and evaluated. The cement mortar flow according to the wood chip aggregate replacement rate showed a tendency to increase as the wood chip aggregate replacement rate increased, and the compressive strength and flexural strength increased as the wood chip aggregate replacement rate increased. The slump and air content of concrete increased as the aggregate replacement rate increased, and the compressive strength and tensile splitting strength of concrete tended to increase as the wood chip aggregate replacement rate increased. Accordingly, the possibility of using the flooring by the cogeneration plant as a fine aggregate for concrete was confirmed.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.689-696
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• 2001

Exergetic and thermoeconomic analysis were performed for a 200kW Phosphoric Acid Fuel Cell(PAFC) plant which offers many advantage for cogeneration in the aspect of high electrical efficiency and low emission. This analytical study was based on the data obtained by in-field measurement of PC25 fuel cell plant to find whether this system is viable economically. For 100% load condition, the electrical efficiency and the unit cost of electricity are about 45% and 0.032 $/kWh respectively, which turn out to be much better than those for the 1000kW gas turbine cogeneration plant. Further, at lower loads, the unit costs of electricity and hot water increase slightly and consequently more economic operation is possible at any loads.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.8
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• pp.439-447
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• 2009

Cogeneration system produces power as well as heat recovered from waste heat during power generation process. This system has higher energy efficiency than that of the power plant. In this study the optimal design for the cogeneration system with the increase of the capacity considering life cycle cost(LCC) analysis has been performed in the general facilities such as hotels and hospitals under the assumption of electricity cost of 95 won/kWh, the initial cost of cogeneration system of 1,500,000 won!kW and the value of 0.5${\sim}$1.0 in the ratio of heat to power. The optimal ratio of cogeneration capacity divided by average electricity load of facility was found out more than 0.5 in case of electricity cost with the increase of>30%, and the percentage of $CO_2$ reduction was about 9%. The most important factors in the economic analysis of cogeneration system was found out the electrity cost and the initial cost of cogeneration system. Also the ratio of heat to power at the value of>0.5 was not affected in the economy of cogeneration system, but was very important in the $CO_2$ reduction.

• Plant Journal
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• v.10 no.2
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• pp.28-37
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• 2014

Recently, it is considered that environment and energy are critical issues all over the world. In power generation sector in Korea, almost power stations are constructed and operated as cogeneration plants in conformity with this trend. KDHC(Korea District Heating Corporation) goes one step further adopting renewable energy technology like heat pump using wasted heat for energy-saving and environment improvement. This study investigates the performance characteristics by the location of waste heat recovery heat pumps of 5 Gcal/h capacity in 150 MW-class Gwang-gyo cogeneration plant using commercial software 'THERMOFLEX'. Prior to analysis, the simulations are performed with actual operation data, and then the validation of simulations is verified by checking the error within 2%. After verification, the simulations are carried out with 3 locations and the effect on electrical power output and heat output is analyzed. As a result, overall efficiency of cogeneration plant is the highest in the case of heat pump located before DH(District Heating) Heater because of the largest increase of heat output despite of decrease of electrical power output.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.321-326
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• 2022

In this study, cogeneration power plants that use biomass as a raw material to convert them into energy have recently received a lot of attention worldwide and are gradually increasing in South Korea. Therefore, in order to confirm the possibility of using the generated floor material as a fine aggregate for concrete, properties and stability evaluation experiments were performed. Compared to standard sand, the compressive strength of wood chip aggregate was improved by 11 % to 111 %, the length change rate was 89 %, and the waste processing test results met all criteria for hazardous substances. All of these are satisfied, and it is judged that the floor materials by the cogeneration power plant can be used as a fine aggregate for concrete.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.248-257
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• 2010

An exhausted heat recovery system for a small gas engine cogeneration plant was investigated. The system was designed and built in a 300 kW class cogeneration demonstrative system. The basic performance was tested depending on load variation, and installed to a field site as a bottoming heat and power supply system. The exhaust gas heat exchangers (EGHXs) in shell-and-tube type and shell-and-plate type were tested. The entire efficiency of the cogeneration system was estimated between 85 to 90% under the 100% load condition, of which trend appears higher in summer due to the less thermal loss than in winter. Power generation efficiency and thermal efficiency was measured in a range of 31~33% and 54~57%, respectively.

• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.41-47
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• 2017

This study aimed to analyze organic Rankine cycle(ORC) which recovers discarded heat from a gas turbine based combined cycle cogeneration(CC-cogen) plant in terms of both performance and economics. The nominal electric power of the CC-cogen plant is around $120MW_e$, and heat for district heating is $153MW_{th}$. The major purpose of this study is to compare various options in selecting heat source of the ORC. Three heat sources were compared. Case 1 uses the exhaust gas from the HRSG, which is purely wasted to environment in normal plant operation without ORC. Case 2 also uses the exhaust gas from the HRSG. On the other hand, in this case, the DH economizer, which is located at the end of the HRSG, does not operate. Case 3 generates power using some of the district heating water which is supplied to consumers. The estimated ORC power generation ranges between 0.3 to 2.3% of the power generation capacity of the CC-cogen plant. Overall, Case 3 is evaluated to be better than other two options in terms of system design flexibility and power generation capacity.

• 열병합발전
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• s.81
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• pp.24-28
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• 2011

• Korean Architects
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• no.3 s.467
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• pp.42-47
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• 2008