• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.135-142
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• 2011

Architectural market in the world is trying to develop Zero Carbon Buildng that doesn"t use fossil fuel. Residential building that thermal load such as heating and domestic hot water is over 70% in energy consumption is easy to make Zero Carbon Building compared with office building that is mainly electric load. So, As a preliminary for analyzing the effect of Solar thermal system in the building, an annual energy consumption of residential building and total heat loads are calculated. Based on this result, three alternatives of solar thermal system for hot water and heating are applied in the building while installation area is increasing. Solar thermal system is applied on balcony and roof of apartment building as the way to reduce thermal load. In the first case that solar thermal system for hot water is applied on the balcony, optimum installation area is $56m^2$. And you could install $40m^2$ of this system in the roof that angle is $30^{\circ}$. In the second case of solar thermal system for heating and hot water, you can install $40m^2$ on the roof. As a result of economic evaluation, the most economical application method is to install $40m^2$ of solar thermal system for only hot water on the roof of the building. At that time, you can payback the initial investing cost within 10 years. And carbon emission of this method can be reduced until about 4 ton per year.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.19-27
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• 2012

This paper describes an experimental study on efficiency of solar collector in solar water heating system connected to hourly water heating load. In general, the functional form of solar efficiency is expressed as a function of fluid temperature entering solar collector, ambient temperature, and solar irradiance. When energy saving from solar heating of water heating system is analyzed on along-term basis such as one year with given solar irradiance data, simplified analysis is more convenient han detailed system simulation for quick assessment. However, the functional form of the efficiency is not convenient for approximately simplified energy analysis because the inlet temperature can be obtained through a detailed system simulation. In the study, solar collector efficiency is obtained with various daily water heating load sand daily solar irradiance using experimental tests. The study also considers large residential buildings such as apartment buildings for application of solar water heating systems. From test results, it is found that daily solar collector efficiency is proportional to daily water heating loads and daily solar irradiance. The data obtained from the study can be utilized to find a functional relation between daily solar irradiance and daily heating load in stead of collector inlet temperature for application of solar collector efficiency to long-term approximated energy analysis of solar heating system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.3
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• pp.241-248
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• 1983

In the present work a time-dependent reliability model for a typical solar domestic hot water and heating system is developed using the method of Fault Tree Analysis and existing mathematical techniques. The reference system used in this analysis is a typical solar heating system. The system reliability structure has been identified with the aid of Fault Tree methods. In addition, a simulation of the solar system reliability has been performed employing the Monte Carlo method. In the computer simulation, failure rate data such as WASH-1400, MIL-HDBK-217B, and Green and Bourne are used as input data. These results show that the developed reliability model is capable of expressing the primary failure phenomena of the solar heating and domestic hot water system.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.768-773
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• 2009

A numerical study has been performed to investigate the thermal Performance of Solar heating system with baffle type of storage tank by using the commercial code TRNSYS. As a result, the solar fraction depends strongly on the efficiency and heat loss coefficient of solar collector as well as the heating capacity of house and the water temperature supplied to the shower. In addition, the solar fraction has been basically ranked to higher level in baffle type of storage tank than typical type of single storage tank for the range of operation condition.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.3
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• pp.108-113
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• 2007

The performance of a solar water heater incorporating evacuated tubes was evaluated using a transient simulation program, TRNSYS. Simulations were performed for $60^{\circ}C$ of hot water load temperature and for 280 liter of daily hot water volumes and three 400 liter of storage tank volumes. Three patterns of daily hot water consumption profile were used in the present study (morning, lunch and evening). The results show that the increase in solar fraction depends on the load profile, as well as the collector efficiency coefficient. Hot water draw profile has a large effect on the performance of the SDHWS, the morning load profile has the highest solar fraction. The annual solar fraction of the system, at the weather conditions of Jinju is approximately 84% at lunch load pattern, the 280 kg of load volume, 400 kg of tank volume and the $60^{\circ}C$ of load temperature.

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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• pp.61-69
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• 2007

The final energy consumption in the building sector in Korea represents almost 20% of the total energy consumption. Besides, Space heating and hot water generation in Korea are based on fossil fuels, with a serious environmental impact. Despite the popularity of simple solar domestic hot water systems, active solar space heating remains, for various reasons, marginal. And thus, the aim of this paper is to demonstrate potentialities of solar assisted space heating systems, both technically and economically. From this study found that the solar heating system with CPC solar collectors integrated the roof of a single-story residential building shares $50{\sim}55%$ of the annual heating load.

• Solar Energy
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• v.4 no.2
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• pp.37-42
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• 1984

A computer code for an optimum design of solar space and domestic hot water heating system has been developed. The f-chart method developed by S.A. Klein et al. has been incorporated in the present computer code. The main conclusions obtained from the present work may be summarized as follows: (1) In Seoul area, about 46% of the total heating load can be obtained from the solar collectors whose total surface area is about one-third of the total heating floor area. (2) In Pusan area, total area of solar collectors should be about half of the total heating floor area in order to obtain an equivalent solar fraction of Seoul. (3) In cheju area, on the other hand, only about 42% of the total heating floor area of solar collectors is needed to get the same solar fraction as in Seoul and Pusan. (4) In order to get the first 50% solar fraction, only about 10-14 collectors ($4'{\times}8'$ collectors) are required, whereas about 48 collectors are needed to obtain the solar fraction of 100%. That is, roughly 3.5-4.5 times greater number of collectors are required to increase the solar fraction from 50% to 100%. Therefore, it can be concluded that it is relatively inefficient and less economical to build a solar system whose solar fraction exceeds more than 50%.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.53-59
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• 2012

This study was carried out to evaluate thermal performance of the renewable hybrid heat supply system with solar thermal system and wood pellet boiler for Zero Carbon Green home of apartment houses. The hybrid heat supply system was set up at Korea Institute Energy Research in 2011. The system was comprised of the wood pellet boiler unit with heat capacity designed as 20,000kcal/hr, a $0.15m^3$ hot water storage tank for space heating, a evacuated tubular solar collector $3.74m^2$ of aperture area at the $20^{\circ}$ install angle, a $0.3m^3$ hot water storage tank. Thermal performance tests for one-house of apartment house were carried out by hot water load and heating load in winter season through the hybrid heat supply system. As a result, hot water energy supplied by the hybrid heat supply system was 11kWh in a day. Solar thermal energy portion was 2.99kWh which is 27% of the total hot water energy supply. wood pellet boiler supply portion was 8.017kWh which is 73% of the total hot water energy supply.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.82-88
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• 2013

There are the stirring test and drain test in the daily performance test to determine the thermal performance of a domestic solar hot water system. The drain test is a test that measures the discharge heating rate while drain the hot water from the top of the storage tank and supply the city water to the bottom of the tank. From the perspective of the user, this drain test is more effective than the stirring test. In this study, the thermal performance were compared through the drain test for a passive type and an active type domestic solar hot water systems consisting of the same storage tank and collectors. At this point, a passive type was used the horizontal storage tanks, and an active type was used vertical storage tank. In the drain test, when the hot water drained up to the reference hot water temperature, an active type which have vertical storage tank represents excellent daily performance than a passive type which have horizontal storage tank regardless of weather conditions. The reason for this is because the vertical storage tank is advantageous to thermal stratification in the tank. After the drain test, the residual heat for the horizontal storage tank was much more than the vertical storage tank, but in the next day the amount of discharged heat were less than the those of vertical storage tank neither. Thus, the solar water heating system which have horizontal storage tank should be adopted preheating control method rather than separate using control method when connected with auxiliary heat source device.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.1-8
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• 2006

The objective of this research is to study on the analysis of long-term performance characteristics of various solar thermal system for heating protected horticulture system for reducing heating cost, increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Long term field test for the demonstration was carried out in horticulture complex in Jeju Island. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Optimum operating condition and its characteristics were closely investigated by changing the control condition based on the temperature difference which is the most important operating parameter. However, it is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.