• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1255-1260
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• 2008

This study is simulation of high elevated liquid line of a modular heat pump system to observe longitudinal subcooling variation. In a high elevated tube, subcooled refrigerant(R410A) through a condenser changes its states by heat transfer with surrounding air and by pressure drop from elevation. In this study, the liquid line was simulated through correlations of heat transfer and pressure drop for the variation from single-phase into two-phase flow. Pressure drop, heat transfer rate and vapor quality were calculated as key parameters. Two-phase turning heights and variations of the key parameters were confirmed from the simulation. As a result, high elevation of liquid line has great influence on upward flow, which requires additional equipment to compensate the variation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.8
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• pp.556-561
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• 2011

In this study, the theoretical maximum power of a heat engine was investigated by sequential Carnot cycle model, for a low-grade heat source of about $100^{\circ}C$. In contrast to conventional approaches, the pattern search algorithm was employed to optimize the two design variables to maximize power. Variations of the maximum power and the optimum values of design variables were investigated for a wide range of UA(overall heat transfer conductance) change. The results show that maximizing heat source utilization does not always maximize power.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.106.1-106.1
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• 2005

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.9-11
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• 1989

A phosphoric acid fuel cell ( PAFC ) power plant with a capacity of SKW a.c has been constructed for R & D purposes at KIER under a sponsorship of KEPCO. The PAFC power plant has successfully generated an electricity for the first time in Korea. In the paper, the plant configuration and the experimental results ace reported.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.15-15
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• 2007

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.176-176
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• 2004

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1356-1358
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• 2003

This paper describes the control of grid connected transformerless type PV power conditioning system, which is simple and more efficient than the usual transformer type system. With the modeling and analysis of power system, the validity of control strategy is well verified through the simulation and experimental results.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.179-183
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• 2002

가압유동층은 복합발전이 가능하며, 총괄열효율이 높을 뿐만 아니라 가압에 의한 장치의 소형화 및 탈황효율의 증대 그리고 배가스 중의 NOx 농도를 줄일 수 있기 때문에 공해 배출 물질의 감소 등 상압유동층 연소에 비하여 많은 장점들을 가지고 있어 선진 국가들에서도 이미 상당한 진전을 보이고 있으며, 중국이나 일본에서도 차세대 연소기술로 이에 대한 연구가 활발히 진행되고 있다.(중략)

• New & Renewable Energy
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• v.2 no.2 s.6
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• pp.37-43
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• 2006

In this paper, the first forecasting system of wind power generation, KIER Forecaster is presented. KIER Forecaster has been constructed based on statistical models and was trained with wind speed data observed at Gosan Weather Station nearby Walryong Site. Due to short period of measurements at Walryong Site for training the model, Gosan wind data were substituted and transplanted to Walryong Site by using Measure-Correlate-Predict(MCP) technique. The results of One to Three-hour advanced forecasting models are consistent with the measurement at Walryong site. In particular, the multiple regression model by classification of wind speed pattern, which has been developed in this work, shows the best performance comparing with neural network and auto-regressive models.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.79-84
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• 2002

The catalytic heat exchanger was designed which employs the regenerative preheating system of combustion air. The characteristics of the catalytic heat exchanger have been experimentally studied at the various operating parameters. The results showed that the mixture velocity did not affect significantly the performance of catalytic combustor whereas the preheating temperature of combustion air affected significantly the conversion rate. The complete conversion was achieved in the catalyzed honeycomb at a preheating temperature of $370-390^{\circ}C$, a mixture velocity of 0.53 $^{\sim}$ 0.75 m/s and an equivalence ratio of 0.19 $^{\sim}$ 0.27. The heat exchange efficiency of the catalytic heat exchanger appeared to be about 75 % when the air of room temperature was used as a working fluid. The results showed that both the heat balance of the system and the mixture conditions determine its stable catalytic combustion.