• Title/Summary/Keyword: Evacuated tube solar energy collector

Search Result 33, Processing Time 0.025 seconds

A Study on the Collector Characteristics of Evacuated Double Glass Tube by Artificial Sun (인공태양에 의한 이중 진공 유리관의 집열특성에 관한 연구)

  • Nam, Yong-Han;Shin, Jae-Ho;Mo, Joung-Gun;Chung, Han-Shik;Jeong, Hyo-Min;Suh, Jeong-Se
    • Proceedings of the KSME Conference
    • /
    • 2003.04a
    • /
    • pp.1542-1547
    • /
    • 2003
  • This paper represents the solar collector performance with type of an evacuate double glass, and a copper tube was installed in center of collector to get a solar thermal energy. The one module of solar collector and artificial sun were used in this experiment The distance between artificial sun and solar collector was fixed at 0.5m, and this experimental condition was focused on winter season. The experiments were carried out. three times for getting a accurate data and the heat amount of one module evacuate d solar collector was estimated at out. 48 kcal/hr.

  • PDF

A Study on Application of a Heat Pipe to an Evacuated Glass Tube Solar Collector (진공 유리관 태양열 집열기에 열파이프의 적용을 위한 기초 연구)

  • Kim, Chul-Joo
    • Solar Energy
    • /
    • v.12 no.2
    • /
    • pp.9-17
    • /
    • 1992
  • This is an experimental work concerning about an application of a heat pipe to an evacuated-glass-tube solar collector system. A methanol heat pipe with length of 0.7 m and diameter of 8 mm was manufactured and tested to compare its performance with that of freon thermosyphon which was originally used in a solar collector system fabricated at Thermomax Co.. Then this methanol heat pipe was utilized to be one component, i.e. heat transfer element, of the present experimental model of a solar collector. This model was performed the operation test as its absorber plate was irradiated by infrared lamps. The following results were obtained. (1) The methanol heat pipe was showed a stable operation when the variation of axial heat transport was $0{\sim}40$ watts and that of inclination angle was $30{\sim}90^{\circ}$. (2) The heat transport capability of the heat pipe was proved to be higher than that of the thermosyphon, because the heat transport limitation of the latter was occured at about 30 watt. (3) The heat pipe in a solar collector was also showed good performance as it transmitted absorbed energy.

  • PDF

Modeling and validation of a parabolic solar collector with a heat pipe absorber

  • Ismail, Kamal A.R.;Zanardi, Mauricio A.;Lino, Fatima A.M.
    • Advances in Energy Research
    • /
    • v.4 no.4
    • /
    • pp.299-323
    • /
    • 2016
  • Cylindrical parabolic solar concentrators of small concentration ratio are attractive options for working temperatures around $120^{\circ}C$. The heat gained can be utilized in many applications such as air conditioning, space heating, heating water and many others. These collectors can be easily manufactured and do not need to track the sun continuously. Using a heat pipe as a solar absorber makes the system more compact and easy to install. This study is devoted to modeling a system of cylindrical parabolic solar concentrators of small concentration ratio (around 5) fitted with a heat pipe absorber with a porous wick. The heat pipe is surrounded by evacuated glass tube to reduce thermal losses from the heat pipe. The liquid and vapor flow equations, energy equation, the internal and external boundary conditions were taken into consideration. The system of equations was solved and the numerical results were validated against available experimental and numerical results. The validated heat pipe model was inserted in an evacuated transparent glass tube as the absorber of the cylindrical parabolic collector. A calculation procedure was developed for the system, a computer program was developed and tested and numerical simulations were realized for the whole system. An experimental solar collector of small concentration, fitted with evacuated tube heat pipe absorber was constructed and instrumented. Experiments were realized with the concentrator axis along the E-W direction. Results of the instantaneous efficiency and heat gain were compared with numerical simulations realized under the same conditions and reasonably good agreement was found.

A Study on the Performance Improvement of All-Glass type Solar Vacuum Collectors (완전유리식 진공관형 집열기의 성능 개선에 대한 연구)

  • Kang, Sang-Hoon;Chun, Won-Gee
    • Journal of the Korean Solar Energy Society
    • /
    • v.22 no.1
    • /
    • pp.43-53
    • /
    • 2002
  • This study has been carried out to study the thermal performance of an all-glass type solar collector tube when a heat transfer medium is used with a heat storage unit capable of preventing pressure build-up within the tube. The heat storage unit is devised such that it performs the dual function of relieving excessive pressure and storing solar thermal energy. Different types of heat storage medium are tested under heat-up phase of a collector tube. It is found that the proposed unit could be used quite effectively if one wishes to capitalize more aggressively in harnessing the solar energy.

Analysis of Operating Characteristics of Large-scale Solar Thermal System Using Two Types of Collectors (두 종류 태양열 집열기를 이용하는 대규모 태양열 시스템의 동작특성 분석)

  • Lee, Dong-Won;Heo, Jae-Heok;Kim, Min-Hwi
    • Journal of the Korean Solar Energy Society
    • /
    • v.37 no.2
    • /
    • pp.67-75
    • /
    • 2017
  • We have investigated the operating characteristics of $1,600m^2$ large-scale solar thermal system installed in an eco-friendly energy town in Chungbuk Innovation City. The operation criteria of the collecting pump and storage pump were different from the existing standard, and it was confirmed that each pump works well according to the changed criteria. Based on the data of the representative day, the daily collecting heat (efficiency) and the production (storing) heat (efficiency) were estimated. It was confirmed that the daily collecting heat (efficiency) of the flat plate type was higher than that of the evacuated tube type, but the useful heat production was more in evacuated tube type collector.

Thermal Performance Variations of Glass Evacuated Tube Solar Collectors Depending on the Absorber Shape and the Incidence Angle of Solar Ray (흡수관 형상과 일사 각도에 따른 진공관형 태양열 집열기의 성능 변화)

  • Kim Yong;Seo Tae-Beom;Kang Yong-Heack
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.17 no.7
    • /
    • pp.659-668
    • /
    • 2005
  • The thermal performances of glass evacuated tube solar collectors are numerically investigated. Four different shapes of solar collectors are considered and the performances of these solar collectors are numerically investigated. Dealing with only collecting tube, the effects of not only the shape of the absorber tube but also the incidence angle of solar irradiation on the thermal performance of the collector are studied because the energy obtained by the absorber can be varied according to the incidence angle of solar radiation. However, the solar irradiation consists of the beam radiation as well as the diffuse radiation. Also, in actual system, the interference of solar irradiation and heat transfer interaction between the tubes should be considered. Therefore, this study considered these effects is carried out experimentally and numerically. The accuracy of the numerical model is verified by experiments. The result shows that the thermal performance of the absorber used a plate fin and U-tube is about $25\%$ better than those of the other models.

Technique of Direct Copper to Glass Seal in an Evacuated Tube Solar Collector (진공관형 태양열 집열기의 구리-유리 직접 접합 기술)

  • Kim, Cheol-Young;Lim, Hyong-Bong;Cho, Nam-Kwon;Kwak, Hee-Youl
    • Journal of the Korean Ceramic Society
    • /
    • v.43 no.9 s.292
    • /
    • pp.544-551
    • /
    • 2006
  • The sealing technique between a glass tube and a copper heat pipe in an evacuated tube solar collector is studied. In this study two different sealing techniques, such as flame method and furnace firing, are examined. After the sealing of a copper to a glass, the oxidation state of the copper and its bonding morphology were examined by SEM and XRD. Its oxidation was retarded by coating of borate solution on the copper, and $Cu_2O(cuprite)$ turned into CuO(tenorite) with increase in a firing temperature and firing time. Porous structure was found in the oxide layer when CuO formed. The best sealing morphology was observed when the thickness of the oxidation layer was less than $20{\mu}m$. The sealing technique performed in a furnace was promising and the satisfactory result was obtained when the sample was fired at $950^{\circ}C$ for 5 min under $N_2$ atmosphere. Annealing procedure is recommended to remove the stress left at the bonding zone.

A study on the thermal performance of all glass evacuated tube collector and refrigerator using solar energy (태양열을 이용한 이중진공관형 집열기와 냉동기의 열성능에 관한 연구)

  • Yoon, Jun-Kyu
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.37 no.4
    • /
    • pp.324-331
    • /
    • 2013
  • All evacuated tube collector is being constantly studied since it can reduce the conductive heat loss in absorber by using vacuum technology and has advantage of heat transport capacity and quick thermal response in comparatively small temperature difference. This study investigated the dynamic thermal performance of the solar collector with the control condition of solar irradiance and fluid temperature by using performance experimental apparatus which is combined with solar collector and refrigerator, examined the thermal characteristics in definite temperature range of fluid in constant temperature tank by simultaneously measuring refrigerating performance. As a result of it, I deducted the related equation of collector efficiency and found that mean collector efficiency has increased through quick heat transfer characteristics according to increase of outdoor temperature and irradiance in case of outlet temperature of constant temperature tank $22^{\circ}C$ when set outlet temperature of solar collector $25^{\circ}C$ with outlet temperature of constant temperature tank $18^{\circ}C$ & $22^{\circ}C$. Also COP of refrigerator was acquired value of 6.2~7.1 at outlet temperature of constant temperature tank $18^{\circ}C$.

Analysis of Thermal Performance of a Solar Heating & Cooling System (태양열 냉.난방시스템의 열성능 분석)

  • Kwak, Hee-Youl;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
    • /
    • v.28 no.4
    • /
    • pp.43-49
    • /
    • 2008
  • The purpose of this study is to present the simulation results and an overview of the performance assessment of a solar heating & cooling system by means of the $200m^2$ evacuated tube solar collector. The simulation was carried out using the thermal simulation code TRNSYS with new model of a single-effect LiBr/$H_{2}O$ absorption chiller developed by this study. The calculation was performed for yearly long-term thermal performance and for two design factors: the solar hot water storage tank and the cold water storage tank. As a result, it was anticipated that the yearly mean system efficiency is 46.7% and the solar fraction for the heating, cooling and hot water supply are about 84.4 %, 41.7% and 72.4%, respectively.

Experimental Study on the Operating Characteristics of a Solar Hybrid Heat Pump System according to Indoor Setting Temperature (실내설정온도에 따른 태양열 하이브리드 열펌프 시스템 운전특성에 대한 실험적 연구)

  • Kim, Won-Seok;Cho, Hong-Hyun
    • Journal of the Korean Solar Energy Society
    • /
    • v.30 no.6
    • /
    • pp.50-58
    • /
    • 2010
  • Experimental study on the operating characteristics of a solar hybrid heat pump system according to indoor setting temperature were carried out during spring and winter season. The system was consisted of a concentric evacuated tube solar collector, heat medium tank, heat storage tank, and heat pump. As a result, the heating load was increased by 21.1% when the indoor setting temperature rose by 2oC for the same ambient temperature. Besides, the spring season had good outdoor conditions compared to the winter season, therefore the heating load was reduced and heat gain by collector increased, relatively. In case of the winter season, the solar fraction was shown less than 10% because the heat losses of system and space increased considerably. The solar fraction decreased significantly as the indoor setting temperature increased.