• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.266-269
• /
• 2009

The Purpose of this study was thermal performance of solar hot water and space heating thermal storage tank. The combi storage tank was designed Tank in Tank type. The tank volume for space heating was 700 $\ell $ and tank volume for hot water was 150 $\ell $. Tank in Tank type storage tank was to replace heat exchange to hot water tank. The result showed that the Heating value was 67.25MJ and domestic hot water value was 51.93MJ. Supply to the hot water volume was 521 $\ell $ more than about 3 times as that of the hot water tank volume.

• Journal of the Korean Solar Energy Society
• /
• v.26 no.4
• /
• pp.127-134
• /
• 2006

In this paper, an experiment was carried out to investigate the thermal behavior and performance on a solar space heating & hot water system in an apartment. Measurement was continued for 6 months between January 1st 2004 and June 31th 2004. The results show that there is no problem in control and operation in case of connection this system with conventional space heating and hot water system, and that the thermal performance of this system and indoor thermal environment is good.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.203-208
• /
• 2009

This paper presents demonstration study results derived through field testing of a solar assisted cooling and heating system for the library of a cultural center building located in Gwangju, Korea. The area of demanded cooling and heating for building was about 350m2. Solar hot water was delivered by means of a 200m2 array of evacuated tubular solar collector (ETSC) to drive a single-effect (LiBr/H2O) absorption chiller of 10RT nominal cooling capacity. From March in 2008 to February in 2009, demonstration test were performed for solar cooling and heating system. After experiments and analysis, this study found that solar thermal system was 84% for the solar hot water supply and 12% for space heating and 4% for space cooling.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.2_2
• /
• pp.271-278
• /
• 2022

The solar energy has been widely used to reduce the fossil fuel and prevent the environmental pollution. The renewable energy including solar heat tends to spread due to carbon neutrality for main country of the world. Targets of solar collector are usually acquisitions of hot water or hot air. Especially, air-heating collector using solar heat is known as the technology for obtaining hot air. This study aims to investigate of characteristics of thermal flow when the hot air by air-heating collector using solar heat flows inside of indoor space. The thermal flow of heating indoor space was simulated using ANSYS-CFX program and thus the behaviors of hot air in indoor space were evaluated with standard k-𝜀 turbulence model. As the results, as the inlet velocity was increased, the behaviors of hot air became simple, and temperature range of 25~75℃ had almost no effect on behavior of flow. As the inlet temperature was increased, the temperature curve of indoor space from bottom to top was changed from linear to quadratic. Furthermore, it was confirmed that inlet velocity as well as inlet temperature also should be considered to heat indoor space equally by air-heating collector using solar heat.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.2
• /
• pp.183-189
• /
• 2012

Most of the domestic residential buildings have used the traditional radiant heating system, circulating hot water through the cross-linked polyethylene(PE-X) pipe buried in the floor panel of the heating space. New type of the heating panel was recently developed using heat pipes with double wicks. Some experiments were carried out in this study to verify the thermal characteristics of this heating system at the unit heating space which surrounded by outer space whose temperature of air be maintained scheduled value with time. Through the various experiments with several parameters, such as flow rate, inlet and outlet temperatures of hot water and the heating duration and so on, we found that the floor heating system with heat pipes was able to reduce the pumping power for hot water circulation by 4~31% compared with the conventional panel heating system using PE-X pipe. These results could be used for optimal design and efficient operation of the heating system as well as improvement of thermal comfort.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.588-592
• /
• 2006

PV Thermal combined system produces the electricity and thermal energy which are needed for buildings. The system removes heat from PV module through air or liquid, so that its efficiency will be improved. The heat as the forms of hot air or hot water can be utilized for building use, like space heating and hot water. This paper describes the concept of PV Thermal combined system and its research and development trend at local and international levels. This materials can be used as a fundamental study source about PV Thermal combined system to apply fur building space heating.

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

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 1991.09a
• /
• pp.41-47
• /
• 1991

This study reports the results of the transient temperature response of a floor heating panel according to variation of the hot water supply temperature and the pipe embedding depth. Also, this experiment compares the temperature responses of floor heating panels under the continuous and intermittent heating system. Furtthermore, this study presents some details of the thermal response of Ondol-heated buildings to varying loads and patterns of heat input. The analysis of the thermal performance fo Ondol heating system have been presented.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.5
• /
• pp.59-67
• /
• 2012

In this study,the compact type solar thermal and ground coupled heat pump hybrid system for space heating/cooling and hot water supply has been developed. This hybrid system was installed in Zero Energy Solar House(ZeSH) in KIER for the demonstration. The thermal performance and operational characteristics of this hybrid system were analysed especially. The results are as follows. (1) This hybrid system was designed in order to address the existing disadvantages of solar thermal/ground coupled heat pump system. For this design, all parts except solar collector and ground coupled heat pump were integrated into a single product in a factory. The compact type unit includes two buffer tanks, an expansion tank, pumps, valves, a controller, etc. This system has an advantage of easy installation with simple plumbing work even in narrow space. (2) The thermal charging and discharging time of the buffer tanks and its characteristics by ground coupled heat pump, and heat pump COP according to geo-source temperature and buffer storage temperature have been studied. This system was found to meet well to the heat load without any other auxiliary heating equipment. (3) The operating hours of the ground coupled heat pump as a backup device of solar thermal can be reduced significantly by using solar heat. It was also found that the minimum heating water supply setting temperature and maximum cooling water supply setting temperature make an influence on the heat pump COP. The lower heating water and the higher cooling water temperature, the higher COP. In this respect, the hybrid system's performance can be improved in ZeSH than conventional house.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.9 no.2
• /
• pp.180-188
• /
• 1997

The theoretical analysis and experiment with simulator were performed to obtain the temperature distributions in radiant heating panel and heat supply from hot water to heating space for the purpose of the development of comfortable living space from a point of view of the improvement of air quality and the enhancement of system efficiency. The relations of various parameters, such as pipe pitch, room temperature as well as flow rate and temperature of hot water and so on, with the rate of heat supplied, mean temperature and maximum temperature difference at panel surface were discussed. The effects of these parameters were also verified on the thermal performance of heating panel using the relations which could be used for the optimal design and operation of the radiant heating panel.