• Title/Summary/Keyword: 접시형 태양열 흡수기 시스템

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A Study on Energy Distributions Produced by Dish Solar Concentrating System (접시형 태양열 집광 시스템의 에너지 분포 특성에 관한 연구)

  • 현성택;강용혁;천원기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.11
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    • pp.907-913
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    • 2002
  • An experimental study on energy density distributions produced by dish solar concentrating system was performed to optimally design and rightly position a cavity receiver. This deemed also very useful to find and correct various errors associated with a concentrator. It is observed that the actual focal length is 2.17 m with a maximum energy density of 1.89 MW/$m^2$. By evaluating the position of flux centroid, it was found that there are errors within 2 cm from the target center. As a result of the percent power within radius, approximately 90% of the incident radiation is intercepted by about 0.06 m radius. The area concentration ratio normalized to 800 W/$m^2$ insolation and 90% mirror reflectivity was 347 suns. The total integrated power of 2467 W was measured under focal flux distributions, which corresponds to the intercept rate of 85.8%.

Thermal Performance of Air receiver with a Change of Flow direction for Dish Solar Collector (공기식 흡수기의 유동 방향에 따른 $5kW_t$급 접시형 태양열 집열기의 열성능 분석)

  • Seo, Joo-Hyun;Kang, Kyung-Moon;Lee, Ju-Han;Oh, Sang-June;Seo, Tae-Beom
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.182-185
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    • 2008
  • The thermal performance of air receiver with a change of flow direction for dish solar collector. This system is installed and operated in Incheon, Korea. The thermal capacity of the system is about 5 kW thermal. The aperture diameter of the cylindrical-shape receiver which is made of stainless steel is 100 mm, and the height is 210 mm. Experiments are being carried out to investigate the thermal performance variation of the receivers with several design parameters such as the shape of the receiver, the flow directions and the flow rate of air. First, air flows into the upper part of the receiver, which is the opposite side of the aperture. After the air flows through the inside receiver, that goes out of the receiver through 3 exits which are located near the aperture. Second, air flows into the backside of the receiver, Which is the forward side of the aperture. After the air flows through the inside receiver, that goes out of the receiver through 1 exit. The results show that the system efficiency and receiver efficiency increase as the volume flow rate increases as expected.

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Computational Heat Transfer Analysis of High Temperature Solar Receiver (수치해석기법을 이용한 고온태양열 흡수기의 열성능 분석)

  • Kim, Tae-Jun;Oh, Sang-June;Lee, Jin-Gyu;Seo, Tae-Beom
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.49-54
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    • 2009
  • This study focus on verification of the thermal efficiency of volumetric receiver with $5kW_{th}$ Dish-type solar thermal system. Spiral flow path shaped on receiver and working fluid(steam) flow along the this flow path. Porous material for radiation-thermal conversion used in former researches are substituted with the stainless steel wall installed along the spiral shaped flow path. Numerical analysis for the flow path and temperature distributions are carried out. Numerical results are compared with experimental data. Using the numerical model, the heat transfer characteristics of spiral type receiver for dish-type solar thermal systems are known and the thermal performance of the receiver can be estimated.

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Numerical investigation of natural convection heat loss in solar receiver for dish concentrating system (접시형 태양열 집광시스템용 흡수기의 자연대류 열손실 수치해석 연구)

  • Kang, Myeong-Cheol;Kang, Yong-Heack;Kim, Jong-Kyu;Kim, Jin-Soo;Yoo, Seong-Yeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.680-683
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    • 2007
  • In dish concentrating system, natural convection heat loss occurs in cavity receiver. Heat loss mechanisms of conduction, convection, and radiation can reduce the system efficiency. To obtain the high efficiency, the receiver is to absorb the maximum of solar energy and transfer to the working fluid with maximum of heat losses. The convection heat loss is an important factor to determine the system performance. Numerical analysis of the convection heat loss of receiver was carried out for varing inclinaton angle from 0$^{\cdot}$ to 70$^{\cdot}$ with temperature range from 400$^{\cdot}C$ to 600$^{\cdot}C$ using the commercial software package, Fluent 6.0. The result of numerical analysis was comparable with convection heat loss model of solar receiver.

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Performance Comparison of Dish Solar Collector With Mirror Arrays & Receiver Shapes (반사경 배치와 흡수기 형상에 따른 접시형 고온 태양열 시스템 성능비교)

  • Ma, Dae-Sung;Kim, Yong;Seo, Tae-Beom
    • Journal of the Korean Solar Energy Society
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    • v.27 no.1
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    • pp.29-38
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    • 2007
  • In order to analyze the performance comparison of dish solar collector with mirror arrays and receiver shapes, the radiative heat flux distribution inside the cavity receiver is numerically investigated. The solar irradiation reflected by dish solar collector is traced using the Monte-Carlo method. Five different dish solar collectors and three different cavity receivers are considered. A parabolic-shaped perfect mirror of which diameter is 1.5 m is considered as a reference dish solar collector and four different arrays of twelve identical parabolic-shaped mirror facets of which diameter are 0.4 m are used. Their reflecting areas, which are $1.5\;m^2$, are the same. Three different cavity receiver shapes are dome, conical, and cylindrical. In addition, the radiative properties of the concentrating surfaces can vary the thermal performance of the cavity receiver so that variation of the surface reflectivity of each mirror is considered. Based on the calculation, the design information of dish solar collector for producing the electric power can be obtained. The results show that the dome type has the best performance in receiver shapes and the 2AND4 INLINE has the best performance in mirror arrays except perfect mirror.

Computational Heat Transfer Analysis of Dish Type Solar Receiver Using the Transient model (CFD를 이용한 접시형 태양열 집열기의 과도 열전달 모델 해석)

  • Oh, Sang-June;Lee, Ju-Han;Seo, Joo-Hyun;Lee, Jin-Gyu;Cho, Hyun-Seok;Seo, Tae-Beom
    • New & Renewable Energy
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    • v.4 no.4
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    • pp.72-79
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    • 2008
  • A numerical and experimental studies are carried out to investigate the transient heat transfer characteristics of 5kWth dish type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical a. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A transient heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Comparing of the experimental and the numerical results, results of both are in good agreement. Using the numerical model, the transient heat transfer characteristics of volumetric air receiver for dish type solar thermal systems are known and the transient thermal performance of the receiver can be estimated.

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Analysis of Transient Heat Transfer Characteristics of a Receiver for a Dish Type Solar Thermal System by using CFD (CFD를 이용한 접시형 태양열 집열기의 Transient 열전달 성능 해석)

  • Oh, Sang-June;Lee, Ju-Han;Seo, Joo-Hyun;Lee, Jin-Gyu;Cho, Hyun-Seok;Seo, Tae-Beom
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.167-170
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    • 2008
  • A numerical and experimental studies are carried out to investigate the transient heat transfer characteristics of 5kWth dish type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical simulation. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A transient heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Comparing the experimental and numerical results, good agreement is obtained. Using the numerical model, the transient heat transfer characteristics of volumetric air receiver for dish type solar thermal systems are known and the transient thermal performance of the receiver can be estimated.

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Design and Preliminary Performance Test for 5kWt Dish Solar Collector ($5kW_t$급 접시형 태양열 집열기의 설계 및 예비 성능실험)

  • Seo, Joo-Hyun;Ma, Dae-Sung;Kim, Yong;Seo, Tae-Beom;Han, Gui-Young
    • Journal of the Korean Solar Energy Society
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    • v.27 no.4
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    • pp.113-120
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    • 2007
  • The 5kWt dish solar collector is designed and the preliminary performance test for this is carried out. The diameter of the parabolic dish is 3.2 m, and its focal length is 2 m. It consists of 10 small reflectors which have their own curvatures, and the effective reflecting area is $5.9\;m^2$, and the rim angle of the dish is $43.85^{\circ}$. The reflectivity of reflectors is 0.95, and the thermal capacity of the system is about 5 kW thermal. The aperture diameter of the cylindrical-shape receiver which is made of stainless steel is 100 mm, and the height is 210 mm. A quartz window is installed at the receiver aperture to minimize the convective heat loss and prevent air leakage. In order to increase the heat transfer area, porous materials (nickel-alloy) are inserted into the receiver. Air flows into the upper part of the receiver which is the opposite side of the aperture. After the air flows through the inside of the receiver, that goes out of the receiver through 3 exits which are located near the aperture. The volumetric flow rates of air are varied from 600 to 1200 L/min. The results show that the system efficiency and receiver efficiency increase as the volume flow rate increases.

Characteristic of a Spiral type Receiver for a Dish type solar thermal system using a Numerical model (수치모델을 이용한 고온 태양열 집열기의 열성능 분석)

  • Kim, Tae-Jun;Kim, Jae-Ik;Lee, Jin-Kyu;Lee, Ju-Han;Seo, Tae-Beom
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.786-791
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    • 2009
  • This study focus on verification of the thermal efficiency of volumetric air receiver with $5kW_{th}$ Dish-type solar thermal system for high temperature uses by using numerical analysis compare with experimental data including shape change of absorber, direction of inlet and outlet. Porous material for radiation-thermal conversion used in former researches are substituted with the stainless steel wall installed along the spiral shaped flow path. Temperature variation and the flow change at the inside of the absorber has been analyzed by Star-ccm+ Version 3.02. Using the numerical model, the heat transfer characteristics of spiral type receiver for dish-type solar thermal systems are known and the thermal performance of the receiver can be estimated.

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Computational Heat Transfer Analysis of High Temperature Solar Receiver (수치해석기법을 이용한 고온태양열 흡수기의 열성능 분석)

  • Kim, Tae-Jun;Lee, Ju-Han;Han, Gui-Young;Kang, Yong-Heack;Seo, Tae-Beom
    • Journal of the Korean Solar Energy Society
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    • v.29 no.4
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    • pp.22-27
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    • 2009
  • This study focus on verification of the thermal efficiency of volumetric receiver with 5k Wth Dish-type solar thermal system. Spiral flow path shaped on receiver and working fluid(steam) flow along with this flow path. Porous material for radiation-thermal conversion used in former researches are substituted with the stainless steel wall installed along the spiral flow path. Numerical analysis for the flow path and temperature distributions are carried out. Numerical results are compared with experimental data. Using the numerical model, the heat transfer characteristics of spiral type receiver for dish-type solar thermal systems are known and the thermal performance of the receiver can be estimated.