• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.360-363
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• 2012

A solar air heating has low efficiency compared with the solar water heating because the heat capacity of the air is small. The heat received by solar collector plate is not fully transferred to the air and then a part of them became the losses to the environment through conduction and convection process. This research is focusing on a design of better combined multi-purposed system suggested by us and aims to secure the more efficient solar energy utilization by combining the hot water and air heating system. The result in this paper has shown that the proposed design has better thermal performance than that of the common design. Furthermore, it was found that the performance of the combined air - water heating system increases the efficiency from 30% to 35%-40%.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.87-94
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• 2011

To develop the solar air heater, prototype of solar heater with test room set up on the roof of test chamber and operation characteristics were examined with solar radiation. Air induced from outside was supplied by a blower and also heated air was supplied to the test chamber(size of 1,000mm(inwidth)*2,000mm(in length)*2,000mm(in depth)) established already for performance. It was clear that almost 30% of solar radiation was converted into effective heating energy at maximum and the highest air temperature was $46^{\circ}C$, and thus solar air heater in winter could be used as an possible alternative heating system in building. Furthermore, heat energy obtained from solar air heater can be applied to regenerate absorber in the solar desiccant cooling system.

• 대한설비공학회지:설비저널
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• 제16권4호
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• pp.392-405
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• 1987

A study of appling solar assisted heat pump heating system to Korean climatic charac-teritics has been undertaken through computer simulation using TRNSYS (A Transient System Simulation Program). It is insufficient for heating system composed of each of solar and heat pump system to supply heat met with heating load. So SAHP (Solar Assisted Heat Pump) heating systems which combined solar system with heat pump system are analized using the standard weather data of Korea. And SAHP heating systems are categorized into the series system in which the solar storage is used as the source for the heat pump, the parallel system in which ambient air is used as the source for the heat pump, and the dual source system in which the storage or ambient is used as the source depending on which source yields the lowest work input. These combined system are better than each of solar and heat pump heating system in view of thermal performance, and parallel system is most effective among these combined systems.

• Journal of Biosystems Engineering
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• 제19권3호
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• pp.211-221
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• 1994

In this study, to maximize the solar energy utilization for greenhouse heating during the winter season, solar energy-underground latent heat storage system was constructed, and the thermal performance of the system has been analyzed to obtain the basic data for realization of greenhouse solar heating system. The results are summarized as follows. 1. $Na_2SO_4{\cdot}10H_20$ was selected as a latent heat storage material, its physical properties were stabilized and the phase change temperature was controlled at $13{\sim}15^{\circ}C$. 2. Solar radiation of winter season was the lowest value in December, and Jinju area was the highest and the lowest value was shown in Jeju area. 3. The minimum inner air temperature of greenhouse with latent heat storage system(LHSS) was $7.0{\sim}7.5^{\circ}C$ higher than that of greenhouse without LHSS and was $7.0{\sim}11.2^{\circ}C$ higher than the minimum ambient air temperature. 4. Greenhouse heating effect of latent heat storage system was getting higher according to the increase of solar radiation and was not concerned with the variation of minimum ambient air temperature. 5. The relative humidity of greenhouse with latent heat storage system was varied from 50 to 85%, but that of greenhouse without LHSS was varied from 30 to 93%. 6. The heating cost of greenhouse with solar energy-latent heat storage system was about 24% of that with the kerosene heating system.

• 대한설비공학회지:설비저널
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• 제8권4호
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• pp.221-236
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• 1979

The three years Performance of a liquid type solar heating system has been determined for a system which has been determined for a system which has been operating continuously since 1976 in Seoul with no serious maintenance. A flat plate collector is used to transform incident solar radiation into thermal energy. This energy is stored if the form of sensible energy and used as needed to supply the space heating loads. An electric auxiliary heaters are provided to supply energy for space heating load when the energy in the storage tank is depleted. The ratio of useful collected solar heat divided by the total solar radiation on the collector was obtained about 84 per cent. It is also obtained the relation between ratio of solar collector area to the heating area and the ratio of useful collected solar energy to the heating load for the useful design data. A comparison between the measured and simulated results with the solar space heating system is described. Hour by hour simulation is made on unsteady state basis using the system parameters and meteorological data at the experiment site. The result of comparison turned out satisfactory for the solar heating system, though the simulation was formed somewhat higher than by experimental.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.232-237
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• 2008

The integration of PV modules into building facades or roof could raise their temperature that results in the reduction of PV system's electrical power generation. Hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The extraction of hot air from the space will enhance the performance of BIPV systems. The solar collector utilizing these two aspects is called PV/T(photovoltaic/thermal) solar collector. This research is about the development of solar roof system with PV/T collector to apply into buildings. A test cell experiment was performed with the PVT roof installed: It found that the hot air supply from the PVT air collector contributed to increase the heating efficiency by 2 times and the electrical efficiency by about 8%.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.37-44
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• 2005

An experimental study was conducted to analyze performance of a heating system with variation of control logic of the system. The system uses a solar as heat source and composed with heat pump that uses R-22 as working fluid. The difference between the developed system and the commercially available heating system is working fluid. The solar assisted heating system which was widely distributed in the market uses water as a working fluid. It could be freezing in case of the temperature drops down under freezing point. The anti-freezing fluids such as methyl-alcohol or ethylene-glycol are mixed with the water to protect the freezing phenomena. However, the system developed in this study uses a refrigerant as a working fluid. It makes the system to run under zero degree temperature conditions. Another difference of the developed system compare with commercial available one is auxiliary heating method. The developed system has removed an auxiliary electric heater that has been used in conventional solar assisted heating system. Instead of the auxiliary electric heater, an air source heat exchanger which generally used as an evaporator of a heat pump was adapted as a backup heating device of the developed system. As results, an efficiency of the developed system is higher than a solar assisted heat pump with auxiliary electric heater. The merit of the developed system is on the performance increment when the system operates at a lower solar energy climate conditions. In case of the developed system operates at a normal condition, COP of the solar collector driven heat pump is higher than the air source heat exchanger driven heat pump's.

• 한국태양에너지학회 논문집
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• 제34권6호
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• pp.49-56
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• 2014

Research about hybrid solar air-water heater that can make heated air and hot water was conducted as a part of improving efficiency of solar thermal energy. At this experiment, ability of making heating air and hot water was investigated and compared with traditional solar air heater and flat plate solar collector for hot water when air or liquid was heated respectively. Comparing hybrid solar air-water heater that used in this experiment to other solar air heater studied already, it has a lower efficiency at same mass flow rate. Air channel structure, fin's shape and arrangement in the air channel result in these difference then the ability of air heating need to be improved with changing these thing. In case of making hot water, performance was shown as similar with traditional system although the air channels were established beneath absorbing plate. But the heat loss coefficient was shown higher value by installing of air channel. Also the performance of hot water making was shown lower value at same liquid mass flow rate with traditional flat plate solar collector for hot water. So the necessity of performance improvement at lower mass flow rate of each heating medium can be confirmed.

• 한국산업융합학회 논문집
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• 제24권4_2호
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• pp.467-474
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• 2021

The renewable energy is known as eco-friendly energy to reduce the use of fossil fuel and decrease the environmental pollution due to exhaust gas. Targets of solar collector in domestic are usually acquisitions of hot water and hot air. System of air-heating collector is one of the technologies for obtaining hot air in cases of especially heating room and drying agricultural product. The purpose of this study is to investigate the characteristics of thermal flow such as relative pressure, velocity, outlet temperature and buoyancy effect in air-heating collector using solar heat. The flow field of air-heating collector was simulated using ANSYS-CFX program and the behaviour of hot air was evaluated with SST turbulence model. As the results, The streamline in air-heating collector showed several circular shapes in case of condition of buoyancy. Temperature difference in cross section of outlet of air-heating collector did not almost show in cases of buoyancy and small inlet velocity. Furthermore merit of air-heating collector was not observed in cases of inlet velocities. Even though it was useful to select condition of buoyancy for obtaining high temperature, however, it was confirmed that the trade off between high temperature of room and rapid injection of hot air to room could be needed through this numerical analysis.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.122-126
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• 2017

태양열 에너지를 이용하여 단순한 형태의 공기가열식 집열기를 이용하여 공기를 가열하고 이를 활용하여 생활공간의 난방문제를 해결하기 위한 장치를 개발하는데 목적을 두고 진행되고 있다. 현 시점에서 연구는 모델로 개발한 공기가열식 태양열에너지 집열기의 크기 변화에 따른 가용한 에너지의 량을 이론적으로 산출해 보고 이를 통해 개발 시스템의 가능성을 판단하고자 한다. 본 연구에서는 공기가열식 태양열 집열기의 공기가열성능을 판단하기 위하여, 특정 크기의 태양열 집열기에 일정한 일사량을 투하하였을 때, 모델 집열기 내부에서의 열전달 특성변화와 이를 통해 생산되는 공기의 온도($^{\circ}C$)와 생산량(kg/h)을, 유한체적법(Finite Volume Method)을 적용한 범용 열유동해석(CFD) 프로그램인 영국 CHAM사의 PHOENICS(1)를 이용하여, 분석한 결과를 구하였다. 분석한 결과에서 알 수 있듯이 집열기의 크기가 ($1.2m{\times}1.1m{\times}0.19m$)의 집열기에서 알루미늄으로 제작하는 내경 0.1m의 공기 가열관을 이용하여 가열할 수 있는 공기의 온도는 약 $40.5^{\circ}C$이며 이때 생산되는 공기의 생산량은 약 $161m^3/h$으로 산출되었다. 본 모델장치는 충분히 태양의 열에너지를 이용하여 실내공간의 온도를 인간이 활동하기에 적합한 활동의 환경을 유지하는데 활용할 수 있다고 판단된다.