• 한국농공학회지
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• 제49권2호
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• pp.61-65
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• 2007

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.42-49
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• 2012

In this article, the author carried out a theoretical study on the application techniques of a new Combined Passive Solar System (hereinafter referred to as the CPSS) of direct gain and trombe walls to get quick morning heating and to prevent afternoon overheating for office building. The numerical model proposed in this study can be used for the performance analysis of the CPSS in the winter and summer. Heating and Cooling loads are analysed for building energy consumption reduction using this numerical model. The results indicate that CPSS in the winter and summer modes could provide profitable conditions for improvement of indoor thermal comfort control and energy saving. consequently, the application of CPSS will not lead to significant reductions in the auxiliary air conditioning demand but also realize the environmentally friendly building.

• 태양에너지
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• 제7권1호
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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.

• 한국태양에너지학회 논문집
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• 제35권4호
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• pp.1-7
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• 2015

The operation of the natural circulation type solar heating systems with facade integrated collector was analyzed by experiment. Two different types of flat plate solar collectors were used for these experiments. One was for the normal flat plate solar collector with the size of 1m*2m and the other was for the large size solar collector with $4m^2$(1m*4m). The experiments were carried out to investigate the effect of the series or parallel connection method on the performance of the collectors. As a result, the solar thermal system which is installed on the wall or facade would be applicable for the natural circulation type if the system design reflects various parameters, including collector connecting method(series or parallel), to provide enough vertical height between collector and storage tank, and to reduce pressure loss due to collector and piping network, etc. The natural circulation type of solar thermal system as proposed in this study can increase the system reliability by removing or minimizing the use of the components such as pump, controller, sensors which may cause serious troubles of the system for a long-time operation

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.45-54
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• 2007

For a conventional natural-circulation type solar water heater, the pressure head is limited by the height between the storage tank and hot water tap. Therefore, it is difficult to provide sufficient hot water flow rate for general usage. This study deals with a design modification of the storage tank to utilize the tap-water pressure to increase hot-water supply Based on fluid dynamic and heat transfer theories, a series of modeling and simulation is conducted to achieve practical design requirements. An experimental setup is built and tested and the results are compared with theoretical simulation model. The storage tank capacity is 240 l and the outer diameter of piping was 15 mm. Number of tube turns tested are 5, 10, and 15. Starting with initial storage tank temperature of $80^{\circ}C$, the temperature variation of the supply hot water is investigated against time, while maintaining minimum flow rate of 10 1/min. Typical results show that the hot water supply of minimum $30^{\circ}C$ can be maintained for 34 min with tap-water supply pressure of 2.5 atm, The relative errors between modeling and experiments coincide well within 10% in most cases.

• 태양에너지
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• 제9권2호
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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.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4463-4468
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• 2014

태양광 모듈 효율의 증가를 위해 렌즈나 반사판 등을 이용한 집광 시스템 개발이 활발하게 진행되고 있으며, 집광장치는 일반적으로 렌즈를 사용하거나 고집속비의 광학장치를 이용하여 태양광 추적형으로 설계하여 고집속화를 추구하고 있다. 그러나 집속비에 비례하여 열로 소산되는 에너지 밀도가 증가하므로, 고집속에 따른 태양전지 온도상승에 의한 태양전지 효율 저하를 방지하기 위해 집광장치의 냉각에 유의해야 한다. 본 논문에서는 이러한 여러 가지 제약 조건을 피하여, 저가격의 반사형 광학장치를 이용한 경제적인 저집광형 태양광 모듈 시스템을 연구 개발하였다. 일반모듈에 저집광장치를 사용하여 태양광 모듈의 발전효율을 증대 시키면서 집광으로 인해 발생하는 열을 냉각장치를 통해 방출하였다. 제안된 저집광형 냉각장치(MCS, Micro Cooling System)의 특징은 모세관력에 의한 자연 순환 방식으로서 외부 동력원이 불필요하며, 유체 상변환시의 잠열을 이용함으로써 고성능 냉각 구현이 가능하다. 117W 태양광 모듈에 반사판을 설치하고 냉각장치가 있는 모듈과 냉각장치가 없는 모듈을 비교 하였다. 냉각장치를 설치한 모듈에서의 발전량이 28% 증가하였다.

• 한국태양에너지학회 논문집
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• 제36권6호
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• pp.25-35
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• 2016

In this study, the evaluation of the dynamic behavior and thermal performance of the "Façade integrated Natural circulation Solar Water Heating System" installed in the residential house was carried out. Experimental tests were performed during the all year around in the rural houses of $166m^2$ in size. Facade integrated solar collector of $5m^2$ were installed on the south-facing. Electrical heater of 1 kW capacity as an auxiliary heater was installed at the upper part of the heat storage tank. The analyzing results are as follows. (1) Monthly average solar fraction was 51 to 87% and yearly average value is 64%. (2) Hot water supply temperature in December which has the lowest solar altitude is 37 to $76^{\circ}C$. The highest working fluid temperature of solar collector in this period was below $84^{\circ}C$. The temperature difference of working fluid between the collector inlet and outlet has been shown to be around 9 to $26^{\circ}C$. (3) Overheating which is one of the biggest problems during summer did not appear at all, but rather had hot water supply temperature is rather low as $30{\sim}47^{\circ}C$ in summer than winter, which is supplied by a small solar load. The solar collecting temperature has been shown to maintain below $55^{\circ}C$. (5) The thermal performance of Facade integrated solar collector can be increase due to the reduction of heat loss to the back of the collector wall integration of the collector is reduced. As a conclusion, Facade integrated natural circulation type Solar Water Heating System is a well-functioning without any pumps or controllers, and it was found that the disadvantages of conventional solar water heaters, hot water or hot water system can be greatly improved.

• 생물환경조절학회지
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• 제9권3호
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• pp.166-170
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• 2000

자연열(태양열)을 효율적으로 이용하기위해 1999년부터 2000년 까지 2년간 상면적이 100$m^2$인 3동의 유리온실에 각기 다른 집열시스템을 설치하였다. 즉, 집열면적과 경사도가 각각 24$m^2$, 50$^{\circ}$로서 현재 시판되고 있는 태양열 집열기(평판형, Solar hart Inc.)를 이용하는 방법, 직경과 송풍량이 각각 1m, 2.5m$^{-3}$.m$^{-2}$ .min로서 라디에이터가 부착된 2개의 유동팬을 천장부에 설치하고 천창을 밀폐한 후 온실상부의 열을 집열하는 방법, 온실의 중도리 전부를 물이 순환되는 각관 (75x45x3t, 1m 간격x10줄x온실길이 12m=120m)으로 설치하여 집열하는 방법 등으로 하였다. 각 동마다 지하에 26톤의 저수 능력을 갖는 D2000xW1500xL8600의 축열조를 설치한 후 중간을 막아 저온수조와 고온수조로 구분하였고, 수조 중간 1.5m 높이에 통수로를 내어 일정량의 물(약 15톤)이 지속적으로 순화될 수 있도록 하였다. 최저기온 9$^{\circ}C$로 설정하여 1,000$m^2$를 공간 난방할 경우 난방연료 절감율은 태양열 집열기, 유동팬 및 각관에서 각각 7%, 19%, 28%로 나타났다. 태양열 집열기를 이용하는 대부분의 농가에서는 40~50$m^2$ 정도의 집열면적을 갖는 집열기를 이용하고 있는데 이 경우 년간 난방연료 절감율은 14% 정도로서 경제성이 없으며, 유동팬도 집열효율에 비해 제작, 설치 및 유지비가 과다하게 소요되므로 경제성이 없다. 각관의 경우 관 자체의 자재비나 설치비에 추가부담이 적으면서 집열효율이 비교적 높기 때문에 관의 부식, 골조 표면적 증가에 의한 시설내 차광 증가, 중도리의 각형 구조로 인한 강도저하 등의 문제가 해결되면 집열 방법으로 고려될 수 있을 것이다.

• 설비공학논문집
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• 제26권6호
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• pp.247-256
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• 2014

The regulations to reduce energy consumption and carbon dioxide emission in building sectors are being developed and promoted all over the world. However, in Korea, as balcony extension of the apartments has been legally allowed, it became prevalent and resulted in excessive energy consumption. This study derived the possibility of PCM application to the thermal storage wall system through theoretical consideration and investigated the problems occurring when the balcony space has been extended to the diverted space. In addition, this study aims at the possibility of verifying the installation and confirming the cooling energy reduction effect, by conducting measuring tests with the actual installation of PCM applied thermal storage wall system. As a result of theoretical consideration, it is determined that the disadvantages with the existing thermal storage wall system can be complemented by applying PCM, and this study suggests the PCM applied Thermal Storage Wall System. The study was conducted on 1/6 of a miniature inner room of a domestic apartment with 84 $m^2$ of exclusive area. From the results of actual measurements, it is confirmed that the balcony extension structure can gain 11.3% of more calories than the existing balcony structure, resulting in the increase in cooling energy usage. It is determined that the installation of the PCM applied Thermal Storage Wall System may gain 25.2% of less calories to reduce cooling energy usage.