• Title/Summary/Keyword: Direct solar radiation

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Performance Prediction of a Solar Power System with Stirling Engine (Matching Collector/Receiver with Engine/Generator Systems) (스털링엔진 태양열 발전시스템의 성능예측(집열기.수열기 및 엔진.발전기 시스템의 조화))

  • Bae, Myung-Whan;Chang, Hyung-Sung
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.794-799
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    • 2001
  • The simulation analyses of a solar power system with monolithic concentrator by using a stirling engine are carried out to predict the system performance in four test sites. The site has different intensities and distributions of direct solar radiation respectively. Seoul, Pusan and Cheju in Korea, and Naha in Japan are selected as test sites. To accomplish the same demand of a 25 kW output that the power level of a system has, it needs to take the matching of collector/receiver with engine/generator systems. In such a case, also, the size of the collector is sometimes adjusted. In this study, the diameter of the collector is decided by using the solar radiation of design point, which is defined as the sum of average and standard deviation $\sigma$ of maximum direct solar radiation distribution for a day during a year in the respective test site. It is found that the average power output during the system operating time in the case of slope error ${\sigma}_s=2.5$ is within the range of 9 to 13 kW.

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Revaluation of Solar Radiation Energy Resources in Korea (국내 태양복사에너지 자원의 재평가)

  • Jo, Dok-Ki;Kang, Young-Heack
    • Journal of the Korean Solar Energy Society
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    • v.29 no.4
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    • pp.15-21
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    • 2009
  • Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.60 kWh/$m^2$/day and the yearly mean 2.62 kWh/$m^2$/day of the direct normal insolation was evaluated for all days.

The Effect of the Materials of an Outer Wall and the Paved Street on Human Thermal Comfort in a Housing Complex in Pohang City (포항시의 집합 주거공간에 있어서 외장재 및 도로 구성재료가 인체 온열 쾌적성에 미치는 영향)

  • Jeong, Chang-Won;Kim, Kyung-Dae;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.3
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    • pp.319-327
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    • 2001
  • The objective of this study is to clarify the effect of thermal radiation environments on human thermal comfort, depending on different canyon types and surface materials on the human thermal comfort in a housing complex in Pohang city, Korea. For this purpose, the operative temperature and new effective temperature were calculated based on the modified mean radiant temperature of canyon models variated by the existence of direct radiation existence, surface materials, and the width and length of the street spaces in a housing complex. These indices for the canyon have been calculated from the meteorological data of Pohang city, which include air temperature, relative humidity, air velocity, global solar radiation and cloud. And the monthly averages of these climate factors measured at noon have been used. The results are as follows: (1) It is revealed that the short-wave radiosity reached the human body is affected by direct solar radiation and surface materials, and the long-wave radiosity by canyon types. (2) The existence of direct solar radiation, the kinds of surface materials and canyon types affect operative temperature($OT_n$) and new effective temperature($ET^*{_n}$). (3) The analysis of the human heat balance in the canyon indicates that the influence of radiation on human body is marc likely to be affected by the existence of direct solar radiation on human model.

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The study of the solar radiation emitted per hour in Incheon applied in load calculation programs (부하계산 프로그램에서 적용되는 인천지역의 시간당 일사량에 관한 연구)

  • Yoo, Ho-Chun;Lee, Seon-Dong
    • Journal of the Korean Solar Energy Society
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    • v.30 no.6
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    • pp.108-117
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    • 2010
  • Although many researches of simulation programs to predict climate under the current climate change have been performed but more detailed studies of weather date which might influence the load of buildings seem insufficient. In this study, in Incheon are analyzed IES (Integrated Environmental Solutions)6.0, Ecotect 2010, EnergyPlus v4.0's IWEC file and ISO-TRY, the Korean standard weather data provided by the Korean Solar Energy Society for direct normal radiation which is used in load calculation programs. The results show that the radiation of the programs is the same as that of direct normal radiation per month but has a mere difference, compared with the radiation per hour and IWEC has also 77.12% when compared with ISO-TRY, meaning that it could affect load values of buildings when applied to them. And in case of ISO-TRY, it could be judged that the application of test reference year applied by the data measured has higher reliability than IWEC file.

Revaluation of Solar Radiation Resources in Korea (국내 태양에너지 자원의 재평가)

  • Jo, Dok-Ki;Kang, Yong-Heack
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.153-156
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    • 2006
  • The domestic solar radial ion data have been measured at 16 different sites all over the country since the beginning of 1980. It is very important that the fundamental data for the estimation and assessment of local solar radiation can be secured this project. In order to estimate available energy resource from solar radiation, it is necessary to have enough data, more than 30 years In any country. However since we have collected solar radiation(global radial ion including direct normal radiation) data only for 10 years we still need to measure insolation to secure the reliability and standardization of measured local solar radial ion data. In brief, the major activities on this R&D include rout me maintenance of the national network for insolation data measurement, evaluation of the collected data, and reliability enhancement for assessing the quality of solar radiation data as well.

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A Basic Study on Urban Radiation Heat Transfer (도시의 방사전열에 관한 기초 연구)

  • Kim, C.M.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.4
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    • pp.35-43
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    • 2002
  • This research makes that quantitative radiation property of an actual town ward is obtained in quest of the parameter with regard to a radiation heat transfer property and set up several town ward models that reproduced a solid form of a city along the attribute of the city. A regular trend possibility that is able to evaluate a radiation characteristics of a town ward quantitatively from a town ward guideline and confirmation that is produced about each parameter as a result of a numerical value simulation it obtained. This research shot a coefficient of Gebhart's emission absorption. sky radiation absorption rate direct solar radiation absorption rate the parameter with regard to a radiation heat transfer characteristics of a town ward in each town ward model and a volume rate of a town ward advances case study under regular such condition and shot the absorption rate, direct and others days and calculated an absorption rate and checked about the relation between a town ward and each radiation heat transfer property of a city.

A Characteristic Analysis of Solar Radiation Resources in Korea (국내 일사량 자원 특성분석)

  • Jo, Dok-Ki;Yun, Chang-Yeol;Kim, Kwang-Deuk;Kang, Young-Heak
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.413-416
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    • 2009
  • Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.61 kWh/$m^2$/day and the yearly mean 5.38 kWh/$m^2$/day of the direct normal insolation was evaluated for clear days.

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New mathematical approach to determine solar radiation for the southwestern coastline of Pakistan

  • Atteeq Razzak;Zaheer Uddin;M. Jawed Iqbal
    • Advances in Energy Research
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    • v.8 no.2
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    • pp.111-123
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    • 2022
  • Solar Energy is the energy of solar radiation carried by them in the form of heat and light. It can be converted into electricity. Solar potential depends on the site's atmosphere; the solar energy distribution depends on many factors, e.g., turbidity, cloud types, pollution levels, solar altitude, etc. We estimated solar radiation with the help of the Ashrae clear-sky model for three locations in Pakistan, namely Pasni, Gwadar, and Jiwani. As these locations are close to each other as compared to the distance between the sun and earth, therefore a slight change of latitude and longitude does not make any difference in the calculation of direct beam solar radiation (BSR), diffuse solar radiation (DSR), and global solar radiation (GSR). A modified formula for declination angle is also developed and presented. We also created two different models for Ashrae constants. The values of these constants are compared with the standard Ashrae Model. A good agreement is observed when we used these constants to calculate BSR, DSR, GSR, the Root mean square error (RMSE), Mean Absolute error (MABE), Mean Absolute percent error (MAPE), and chisquare (χ2) values are in acceptance range, indicating the validity of the models.

A Revaluation of Solar Energy Resources in Korea (국내 태양에너지 자원의 재평가)

  • Jo, D.K.;Chun, I.S.;Jeon, M.S.;Kang, Y.H.;Auh, C.M.
    • Journal of the Korean Solar Energy Society
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    • v.21 no.4
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    • pp.73-83
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    • 2001
  • Since the solar radiation is the main input for sizing any solar system, it will be necessary to understand and evaluate the insolation data. The horizontal global insolation data have been measured since May, 1982 and direct normal solar insolation data since December 1990 at 16 different sites all over the country and considerable effort has been made for constructing a standard value from measured data at each station. In the results, the average global total solar radiation of the nation is $3,055kcal/m^2.day(12.79MJ/m^2.day)$ and the average clear day direct normal solar beam radiation was $4,600kcal/m^2.day(19.26MJ/m^2.day)$, which indicates possible solar energy application of medium and high temperature technologies with high concentration.

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Analysis of Solar Radiation Components for the Installation of Solar Thermal System in Korea (국내 태양열시스템 설치를 위한 성분일사량 분석)

  • Jo, Dok-Ki;Kang, Young-Heack
    • Journal of the Korean Solar Energy Society
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    • v.29 no.3
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    • pp.12-18
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    • 2009
  • The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since January, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The theoretical analysis of solar radiation as a component has compared with the experimental data obtained by the KIER station. The Result of simulation analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,457cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.