• 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.

• 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.

• Solar Energy
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• v.9 no.2
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• pp.3-13
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• 1989

This study has been conducted to measure the performance of 5 thermosyphon solar water heaters suitable for Korean climate and to develop the most optimum system. Each system consists of two flat plate collectors of $4'{\times}8'$ (or three flat plate collectors of $3'{\times}6'$) connected in parallel and a storage tank of $300{\ell}$ capacity. Among the tested systems, the configuration that has two flat plate collectors of $4'{\times}8'$ and a horizontal tank-in-tank type storage unit with internal fins (C system) showed the highest performance.

• 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.7 no.1
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• pp.3-13
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• 1987

A batch type passive solar water systems, which perform the dual function of absorbing the solar energy and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing at KIER. The test models included an A, B and C type batch systems which were classified according to the design of box and arrangement of tanks. The year-round performance tests show that B type batch system taken the step-wise tank arrangement indicates 55.7% yearly-average collection efficiency factor and 61% yearly-average maximum collection efficiency factor. Computer-aided-experimental results show that the sufficient hot water can be obtained in the early morning if the glazing is supplemented by a reflector/insulation cover. The thermal performance equation has been developed for the prediction of hourly variation of the water temperature in tank.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.45-51
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• 2002

CES(Community Energy System)란 구역형의 소규모 지역냉난방시스템으로 세계에서 일본이 가장 발달된바, 일본의 도입 실태분석이 향후 국내 CES 도입에 중요한 자료가 될 것으로 판단되므로 일본에서의 소규모 지역냉난방시스템 도입사례에 대한 조사분석한 내용을 소개하고자 한다. 일본에서의 지역열공급사업의 개념은 1개소 또는 수개소의 열공급플랜트로부터 복수의 건물에 지역배관을 통하여 냉수ㆍ증기ㆍ온수 등을 보내어 냉난방ㆍ급탕을 행하는 것이다.(중략)

• Solar Energy
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• v.4 no.2
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• pp.29-36
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• 1984

This paper reviews the current status of R&D work on selective absorber materials. For the efficient utilization of solar energy, various types of selective absorber materials are being used for solar hot water heaters. Many selective absorbers which have been proposed and designed up to data are classified according to the absorption mechanisms. Temperature-time cycle method is often recommended for the measurement of solar absorptance. In addition, conversion efficiency of the solar collector with selective surface is compared with one with black paint surface.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.199-199
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• 2007

• 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.

• 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.