• Solar Energy
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• v.18 no.2
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• pp.1-17
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• 1998

In order to analyze the status of development of solar thermal technology in Korea, importance and characteristics of solar thermal technology is considered. That is, solar collector, solar hot water heater, solar industrial system and solar buildings is analyzed in the view of worldwide technology, And then, domestic insolation sources and sale amounts of solar system is introduced. In this paper, it Is presented long-term objective in the basic plan of development new & rowable energy in Korea. As a result of analysis, the status of solar thermal technology in Korea is pactical use state in the field of low temperature use and application state in the field of mid-temperature use.

• Journal of the Korean Solar Energy Society
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• v.38 no.5
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• pp.49-62
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• 2018

This study aims to analyze the performance of solar thermal system with heat pump for domestic hot water and heat supply. There are four types of system. Systems are categorized based on the existence of a heat pump and the ways of controlling the working fluid circulating from the collector. Working fluid is controlled by either temperature level (categorized as system 1 and 2) or sequential flow (system 3 and 4). Heat balance of the system, the solar fraction, hot water and heating supply rates, and performance of heat pump are analyzed using TRNSYS and TESS component programs. Technical specifications of the main facilities are as follow; the area of the collector to $25m^2$, the volumes of the main tank and the buffer tank to $0.5m^3$ and $0.8m^3$, respectively. Heating capacity of the heat pump in the heating mode is set to 30,000 kJ / hr. Hot water supply set 65 liters per person each day, total heat transfer coefficient of the building to 1,500 kJ / kg.K. Indoor temperature is kept steadily around $22^{\circ}C$. The results are as follows; 6 months average solar fraction of system 1 turns out to be 39%, which is 6.7% higher than system 2 without the heat pump, indicating a 25% increase of solar fraction compared to that of system 2. In addition, the solar fraction of system 1 is 2% higher than that of system 3. Hot water and heating supply rate of system 1 are 93% and 35%, respectively. Considering the heat balance of the system, higher heat efficiency, and solar fraction, as whole, it can be concluded that system 1 is the most suitable system for hot water and heat supply.

• Journal of the Korean Solar Energy Society
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• v.39 no.6
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• pp.41-54
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• 2019

The purpose of this study is to analyze the performance of solar thermal system according to regional weather conditions and feedwater temperature. The performance analysis of the system was carried out for the annual and winter periods in terms of solar fraction, collector efficiency and it's optimal degree. The system is simulated using TRNSYS program for 6 cities, Seoul, Incheon, Gangneung, Mokpo, Gwangju, and Ulsan. Simulation results prove that the solar fraction of the system varies greatly from region to region, depending on weather conditions and feedwater temperatures. Monthly average solar fraction for winter season from November to February, a time when heat energy is most required, indicated that the highest is 73.6% in Gangnueng and the lowest is 56.9% in Seoul. This is about 30% relative difference between the two cities. On the other hand, the collector efficiency of the system for all six cities was analyzed in the range between 40% and 42%, indicating small difference compare to the solar fraction. The annual average solar fraction is rated the highest at 40 collector degree, while monthly average solar fraction during winter season is rated at 60 degree.

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.11-11
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• 2006

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.10-10
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• 2006

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.189-189
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• 2003

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.243-243
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• 2004

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.199-202
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• 2009

Domestic new recycling energy supply is on the way in various form and capacity locally through the support of governmen aid. Among these, solar energy supply is the most in scale and facility. In this paper, we intended to analysis the characteristics of solar energy operation system with season.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1418-1423
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• 2009

This study describes experimental study on the performance characteristics with load condition in hybrid solar heating system during spring season. The room temperatures, the hot water conditions and the lower part temperatures of heat storage tank were changed to analyze the system performances. As a results, the hot water was significantly affected by the ambient temperature. The indoor setting temperature affected the solar fraction. When the low part temperature of the storage tank increased, the temperature of the hot water rose and the temperature of the hot water in morning was affected by the ambient temperature.

• Solar Energy
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• v.8 no.1
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• pp.74-81
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• 1988

A preliminary study has been done to investigate the thermal performance of an indirect system. Direct systems are also analyzed and the results are compared with those of the indirect system where possible. Values from the numerical simulation show very good agreement with the measured data. Although the indirect system is generally expensive and not as efficient as direct systems, it is more reliable in frigid weather conditions like the winters in Korea.