• Title/Summary/Keyword: external heat method

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A Study on Thermal Characteristics of Hybrid Solar Receiver for Dish Concentrating System (고온용 태양열 복합 흡수기의 열특성 분석 연구)

  • Kang, Myeong-Cheol;Kim, Jin-Soo;Kang, Yong-Heack;Kim, Nack-Joo;Yoo, Seong-Yeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.571-575
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    • 2006
  • To improve economic of solar power generation, stirling engine is required continuous operation and the receiver has to be provided with an additional combustion system. The hybrid receiver with a specially adapted combustion system is possible to 24 hr/day operation by solar and gas-fired. The inner cavity and external wall serve as absorber surfaces using collected irradiation and heat transfer surfaces for the gas heat flow, respectively. The hybrid receiver was designed and fabricated for the dish/stirling system. The analytical method for pridicting natural convective heat loss from receiver is used. The Koenig and Marvin model is used to estimate convection heat loss and heat transfer coefficiency.

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An Investigation of Thermal Margin for External Reactor Vessel Cooling(ERVC) in Large Advanced Light Water Reactors(ALWR)

  • Park, Jong-Woon;Jerng, Dong-Wook
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05a
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    • pp.473-478
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    • 1997
  • A severe accident management strategy, in-vessel retention corium through external reactor vessel cooling(ERVC) is being studied worldwide as a means to prevent reactor vessel failure following a core melt accident. An evaluation of feasibility of this ERVC for a large Advanced Light Water Reactor (ALWR) is presented. To account for the coolability of corium and metal in the reactor vessel, a thermal analysis is performed using an existing method. Results show that the peak heat flux along the inner surface of the reactor vessel lower head has a relatively smaller margin than a small capacity reactor such as AP600 in regards with the critical heat flux attainable at the outer surface of the reactor vessel lower head.

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Deflection Characteristics of Permanent Formwork Using Multi-layer Insulation (다층형 단열재를 사용한 영구거푸집의 처짐 특성)

  • Ryu, Hwa-Sung;Shin, Sang-Heon;Song, Sung-Yong;Kim, Deuck Mo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.130-131
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    • 2019
  • As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. In addition, the conventional styrofoam insulating material has a problem that the thickness of the heat insulating material to achieve a standard heat permeability is rapidly increased. Due to the thick insulation, there is a high risk of spreading vulnerable structures such as fire due to lack of space between buildings. On the other hand, the method of using the insulation as a formwork is known to be excellent cost saving effect through the reduction of the formwork usage and the simplification of the external insulation work. In order to solve this problem, this study aims to fabricate a multi-layered insulator that combines high-performance phenolic foam insulation and styrofoam insulation and evaluate the deflection characteristics for use as formwork.

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Literatural study on the cause of the Infantile Vomiting (소아구토(小兒嘔吐)의 병인병리(病因病理)에 관한 동서의학적(東西醫學的) 문헌적(文獻的) 고찰(考察))

  • Han, Jae Kyung;Yoo, Dong Yeol
    • Journal of Haehwa Medicine
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    • v.9 no.1
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    • pp.337-352
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    • 2000
  • According to the literatual study on the Infantile Vomiting since the publication of ${\ll}Hwangjenaekung{\gg}$, the results were as follows. 1. The causes of vomiting are classified into the following kind: external cause are the cold and heat, not external and internal are disorder of food and mood, internal are the dysfuntion of spleen, stomach, liver, kidney. 2. The Oriental Medical cause of Infantile Vomiting is disorder of food, intusion of outside evil, heat accumulation in the stomach, deficiency of stomach liquid, reverse flowing of Qi resulted from fear and being frightened. There are so many causes of Infantile Vomiting, but they are all related to the stomach. 3. The Western Medical cause of Infantile Vomiting are classified with the situation of stimulation, age, accompanied symptom. The main cause related with the age is inhalation of amniotic fluid, maternal blood, infectious disease, wrong lactation method, functional and organic abnormality. 4. The Infantile Vomiting is similar with the adults, but the spleen and stomach of infants is so feeble that the vomiting happens very easily. The reverse flowing of Qi resulted from fear and being frightened and disorder of food are the main cause in infants. 5. The cause of Infantile Vomiting between Oriental Medicine and Western's is so similar and both emphasized the function of spleen and stomach. But the comment on the external cause(cold, heat) and not internal & external cause(mood disorder) is a creative view of Oriental Medicine.

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A literature study on the nasal stuffiness (鼻塞의 病因.病機.治療에 對한 文獻的 考察)

  • Yun, Chan-ho;Roh, Sek-seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.295-312
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    • 1999
  • A literature study on the nasal stuffiness, the results are as follows. 1. The pathogenic factors nasal stuffiness are wind-cold, cold, fire-heat, heart & lung disease, deficiency of lung-energy and spleen & stomach disease caused by internal damage. 2. The method on the external treatment of nasal stuffiness are obstructive method, blowing method and pouring method, obstructive method used many. 3. The method on the internal treatment of nasal stuffiness are diaphoretic therapy, clearing away heat & toxic materials and warming the lung & invigorating the spleen. 4. You-taek-tong-gue-tang is used in nasal stuffness. 5. Herba Asari, Radix Angelicae Dahuricae, Flos Magnaliae, Fructus Xanthii, Rhizama Acori Graminei, Herba Menthae, Zanthoxyli Fructus and Spina Gleditsiae are used in nasal stuffness.

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Literatural Study on the cause of a disease and prescription in migraine (편두통(偏頭痛)의 원인(原因)과 처방(處方)에 대한 문헌적(文獻的) 고찰(考察))

  • Kim, Jong-In;Hwang, Chi-Won
    • Journal of Haehwa Medicine
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    • v.8 no.2
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    • pp.171-189
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    • 2000
  • By Literatural studying on migraine, The results were obtained as fallow : 1. A different name on migraine were called hemicrania(頭偏痛, 邊頭痛, 偏頭風). 2. In the cause of a disease in migraine, the cases were clasified into the fallowing kind : internal cause were a decline in energy and blood(氣血具虛), external cause were outside evil(外邪) in wind cold heat wetness(風寒暑濕), non internal, external cause were exhaustion. The right side migraine were concerned phlegm heat, the right side migraine were concerned wind decline in blood. 3. Migraine is appeared on the side, For the reason, liver function in excess of normal limits(肝陽上亢), a sudden of liver fire(肝火) is becomeed of invasion upon soyangkuong(少陽經) in internal external cause 4. Usage method of medicines is appeared that order underclothes theraphy(內服法), to pump out in nose theraphy, to join head theraphy(頭點法), heating smoke theraphy(熏煙法) 5. CNIDII RHIZOMA(川芎) is in mostly general use for migraine, in that order LEDEBOURIELLAE RADIX(防風) ANGELICAE DAHURICAE RADIX(白芷) ASARI HERBA CUM RADICE(細辛) NOTOPTERYGII RHIZOMA(羌活) GLYCYRRHIZAE RADIX(甘草) CHRYSANTHEMI FLOS(菊花) BUPLEURI RADIX(柴胡) SCUTELLARIAE RADIX(黃芩) ANGELICAE GIGANTIS RADIX(當歸) GYPSUM FIBROSUM(石膏) MENTHAE HERBA(薄荷) GLYCYRRHIZAE RADIX(炙甘草) VITICIS FRUCTUS(蔓荊子), nature is in mostly general hot warm(辛溫), bitter cold(苦寒), guikuong(歸經) is in mostly general liver gall kuong(肝膽經), efficacy is in mostly general to remove wind pain (祛風止痛) and to down fire(瀉火).

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A Numerical Study on the Laminar convective Heat Transfer around a Circular Cylinder in a Uniform Cross Flow of Liquid (액체중의 원형 실린더 주위에서의 강제대류 층류 열전달에 관한 수치해석적 연구)

  • 강신형;홍기혁
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.8 no.1
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    • pp.26-36
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    • 1996
  • Many researches were carried out to estimate heat transfer rate on a circular cylinder in a uniform flow. Various empirical correlations were suggested in the past through experimental studies, however there are considerable discrepancies in the estimated values of heat transfer coefficient. The effect of fluid physical properties on the forced convective heat transfer between a circular cylinder and the external flow was numerically investigated in the present study, The flow and temperature fields were solved using a Finite Volume Method over a wider range of Prandtl number(0.7-40,000) than existing correlations. The cold as well as the hot cylinders in the uniform liquid flow of constant temperature were investigated. A unified correlation was obtainde for both cases.

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Development of the Temperature Prediction Program for the Bus Bar of a Gas-insulated Switchgear (가스차단기 모선부의 온도상승 예측 프로그램 개발)

  • Ham, Jin-Ki;Kim, Young-Ki;Lee, Hee-Won;Kim, Jin-Soo;Song, Seok-Hyun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.169-174
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    • 2003
  • The thermal design of the bus bar of a Gas-Insulated Switchgear(GIS) becomes important since the current-carrying capacity of the GIS is limited by maximum operating temperature. In order to predict temperature rise of the bus bar, a program has been developed. Various heat sources possibly generated in the bus bar are calculated in the program. To estimate temperature rises at the bus bar caused by the heat balance between the heat generation and heat transfer, the finite volume method as well as the $4^{th}$ order Runge-Kutta method has been employed. In the experiments, temperature rises at conductor, contact part and external tank are measured for full-scale gas-insulated bus bars. The comparisons of the predicted values of the heat balance calculation to those of the experiments are made. From the comparisons, it is concluded that the developed program can predict the temperature rise of the bus bar quite well.

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Numerical Simulation of Boiling 2-Phase Flow in a Helically-Coiled Tube (나선형코일 튜브 비등2상 유동 수치해석)

  • Jo J. C.;Kim W. S.;Kim H. J.;Lee Y. K.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.49-55
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    • 2004
  • This paper addresses a numerical simulation of the flow and heat transfer in a simplified model of helically coiled tube steam generator using a general purpose computational fluid dynamic analysis computer code. The steam generator model is comprised of a cylindrical shell and helically coiled tubes. A cold feed water entered the tubes is heated up, evaporates. and finally become a superheated steam with a large amount of heat transferred continuously from the hot compressed water at higher pressure flowing counter-currently through the shell side. For the calculation of tube side two-phase flow field formed by boiling, inhomogeneous two-fluid model is used. Both the internal and external turbulent flows are simulated using the standard k-e model. The conjugate heat transfer analysis method is employed to calculate the conduction in the tube wall with finite thickness and the convections in the internal and external fluids simultaneously so as to match the fluid-wall-fluid interface conditions properly. The numerical calculations are peformed for helically coiled tubes of steam generator at an integral type pressurized water reactor under normal operation. The effects of tube-side inlet flow velocity are discussed in details. The results of present numerical simulation are considered to be physically plausible based on the data and knowledge from previous experimental and numerical studies where available.

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The Oriental and Occidental bibliographic Study of Psoriasis (乾癬에 對한 東.西醫 文獻的 硏究)

  • Kim, Nam-Kwen;Hwang, Chung-yeon;Lim, Gye-sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.154-178
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    • 1999
  • Psoriasis is the recurrent disease of skin and till now its mechanism, pathogenesis and treatment are not clearly discovered. So, like these papers, we must investigate more safety and effective treatment of psoriasis. And I obtained the following condusions from the Oriental and Occidental bibliographic investigation. 1. In Oriental medicine. Baikbi, Pungsun, Eunselbyong, Songpisun, Baikselpung were the other names of Psoriasis. 2. In Occidental medicine, genetic factors, aggravation and inducible factors, biochemical factors, immunologic factors, disorder of epidermal kinetics, vascular malformation of dermis were cosidered to the pathogenic factors of psoriasis. 3. In Oriental medicine, the pathogenic factors of psoriasis were divided two parts. One is exogenous pathogenic factors which including the blood-heat, blood dryness, blood stasis, deficiency of liver and kidney, inharmony of impulsive and appointed pulsation, deficiency of blood. The other is exogenous pathogenic factors which including the wind-evil, wind-wetness, wind-heat, wind-cold, wetness-heat, cold-wetness, heat-evil. 4. In Occidental medicine, external applicative medicine, internal medicine, ultraviolet therapy, ultraviolet - external applicative medicine compound therapy and etc. were used the therapy of psoriasis. 5. In Oriental medicine, clean away heat and cooling blood, aliment the blood and moisturize, activating blood and expelling blood stasis, harmonize and invigorate the liver and kidney, invigorate the kidney, aliment the blood and moisturize the skin, aliment the blood and expelling the wind, expelling the wind and wetness, clean away heat and expelling wind, expelling the wind and scatter the cold, clean away heat and expelling the wetness, heat up the meridian and scatter the cold, clean away heat and remove the toxin and etc. were used the method of internal therapy of psoriasis. 6. Until Qing dynasty, wind expelling effective prescriptions like Bangpungtongsungsan, Sopungsan. Supungsunkisan and etc. were used and recently Yanghyelgeupungtang, Hwalhyelgeupungtang, Samultanggagam and etc. were used the internal therapy of psoriasis. 7. In the external therapy of psoriasis, Yuhonggo, Pungyugo, Sekryupiyeongo were used the plaster therapy and Folium Rerillae, Camphora, Fructus, Xanthii, Herba Spirodelae compound prescription were used the cleansing therapy, Okgisan, Chiunsan, Galmyogo, Hobunsan, Muisan, Madugo, Jeyugohengin were used the rubbing skin therapy. Rangdok Radix Aconiti, Bijeonilchoalkwang were used the attaching therapy, the extract of Rhizoma Et Radix Veratri was used the spreading pouder therapy. 8. In the acupuncture therapy of psoriasis, the Jelgol, chok Samni(S36), Kansa(P5), Haegye(S41), Wijung(B40) and etc. were used the acupuncture point, and the angle of helix incision threapy that disinfect and cut the angle of helix and plaster the Semen Glycine and Squama Manitis were used.

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