• Title/Summary/Keyword: Heat Load Analysis

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Thermal Analysis of a Cryochamber for an Infrared Detector Considering a Radiation Shield (적외선 검출기용 극저온 챔버에서 복사 차폐막을 고려한 열해석)

  • Kim Young-Min;Kang Byung-Ha
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.8
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    • pp.672-677
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    • 2006
  • The steady cooling characteristics of a cryochamber for infrared (IR) detector have been investigated analytically, considering radiation shields. The thermal modeling considers the conduction heat transfer through cold finger, the gaseous conduction due to out-gassing, and the radiation heat transfer. The cooling load of the cryochamber is obtained by using a fin equation. The results obtained indicate that the gaseous conduction plays an important role in determining the steady cooling load. The steady cooling load is increased as the gas pressure is increased. It is also found that the cooling load is substantially decreased with a radiation shield. The most thermal load of a cryochamber occurs through the cold finger.

An Experimental Study on Heat Transfer and Flow in Compression Molding of SMC (SMC 압축성형의 열 및 유동에 관한 실험적 연구)

  • 김기택;정진호;임용택
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.9
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    • pp.2386-2395
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    • 1994
  • An experimental study on heat transfer and flow in compression molding of clss-B and A SMC(Sheet Molding Compounds) in a flat plate and a cross-sectional T-shape was carried out. The temperature was measured with thermocouples at two locations in the 4 layered SMC charge and pressure was measured at the center of the top mold during compression molding. Three different mold speeds, 15, 45, 50 mm/min and two different mold temperature, $130^{\circ}C{\;}and{\;}150^{\circ}C$ were used for compression molding experiments. Experiments with different colored SMC layers were used to study flow patterns at various compression stages. In oder to predict the pressure and load in SMC compression molding, slab method was used. The predicted values of pressure and load from the slab analysis were compared well with the measured data.

Study on the Operation of the Solar Heating System with Ground Source Heat Pump as a Back-up Device (지열히트펌프 보조열원식 태양열 난방급탕 시스템 작동에 관한 연구)

  • Kim, Hwidong;Baek, Namchoon;Lee, Jinkook;Shin, Uchul
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.197.2-197.2
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    • 2010
  • The study on the operation characteristics of solar space and water heating system with ground source heat pump (GSHP) as a back-up device was carried out. This system, called solar thermal and geothermal hybrid system (ST/G), was installed at Zero Energy Solar House II (KIER ZeSH-II) in Korea Institute of Energy Research. This ST/G hybrid system was developed to supply all thermal load in a house by renewable energy. The purpose of this study is to find out that this system is optimized and operated normally for the heating load of ZeSH-II. Experiment was continued for seven months, from October to April. The analysis was conducted as followings ; - the contribution of solar thermal system. - the appropriateness of GSHP as a back-up device. - the performance of solar thermal and ground source heat pump system respectively. - the adaptation of thermal peak load - the operation characteristics of hybrid system under different weather conditions. Finally the complementary measures for the system simplification was referred for the commercialization of this hybrid system.

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Analysis of Design and Part Load Performance of Micro Gas Turbine/Organic Rankine Cycle Combined Systems

  • Lee, Joon-Hee;Kim, Tong-Seop
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1502-1513
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    • 2006
  • This study analyzes the design and part load performance of a power generation system combining a micro gas turbine (MGT) and an organic Rankine cycle (ORC). Design performances of cycles adopting several different organic fluids are analyzed and compared with performance of the steam based cycle. All of the organic fluids recover greater MGT exhaust heat than the steam cycle (much lower stack temperature), but their bottoming cycle efficiencies are lower. R123 provides higher combined cycle efficiency than steam does. The efficiencies of the combined cycle with organic fluids are maximized when the turbine exhaust heat of the MGT is fully recovered at the MGT recuperator, whereas the efficiency of the combined cycle with steam shows an almost reverse trend. Since organic fluids have much higher density than steam, they allow more compact systems. The efficiency of the combined cycle, based on a MGT with 30 percent efficiency, can reach almost 40 percent. hlso, the part load operation of the combined system is analyzed. Two representative power control methods are considered and their performances are compared. The variable speed control of the MGT exhibits far better combined cycle part load efficiency than the fuel only control despite slightly lower bottoming cycle performance.

Estimation of Adequate Capacity of Ground Source Heat Pump in Energy-saving Pig Farms Using Building Energy Simulation (BES를 사용한 에너지 절감형 양돈장의 지열히트펌프 적정 용량 산정)

  • Lee, Seong-Won;Oh, Byung-Wook;Park, Kwang-Woo;Seo, Il-Hwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.1
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    • pp.1-13
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    • 2022
  • In Korea, attention is being paid to the use of renewable energy in the livestock industry, and Ground Source Heat Pump (GSHP), which is advantageous for temperature control, is considered as one of the ways to reduce the use of fossil fuels. But GSHP is expensive to install, which proper capacity calculation is required. GSHP capacity is related to its maximum energy load. Energy loads are affected by climate characteristics and time, so dynamic analysis is required. In this study, the optimal capacity of GSHP was calculated by calculating the heating and cooling load of pig farms using BES (Building Energy Simulation) and economic analysis was performed. After designing the inside of the pig house using TRNSYS, one of the commercial programs of the BES technique, the energy load was calculated based on meteorological data. Through the calculated energy load, three heating devices and GSHP used in pig farms were analyzed for economic feasibility. As a result, GSHP's total cost of ownership was the cheapest, but the installation cost was the highest. In order to reduce the initial cost of GSHP, the capacity of GSHP was divided, and a scenario was created in which some of it was used as an auxiliary heating device, and economic analysis was conducted. In this study, a method to calculate the proper capacity of GSHP through dynamic energy analysis was proposed, and it can be used as data necessary to expand the spread of GSHP.

Thermal Stress Analysis for the Printed Circuit Board of Electronic Packages (전자장비 회로기판의 열응력해석)

  • Kwon Y. J.;Kim J. A.
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.4
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    • pp.416-424
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    • 2004
  • In this paper, the heat transfer analysis and thermal stress analysis of the PCB(Printed Circuit Board) equipped in electronic Packages are carried out for various may types of chips on the PCB. And two structural PCB models are used in the analyses. The electronic chips on the PCB usually emit heat and this heat generates the thermal stress around the chip. The thermal load due to the heat generation of chips on the PCB may cause the malfunction of the electronic packages such as a monitor. a computer etc. Hence, the PCB should be designed to withstand these thermal loads. In this paper, the heat transfer analysis and thermal stress analysis are executed for the PCB model with pins and the analysis results are compared with the results for the PCB model without pins. The analysis results show that the PCB model without pins is not good for the thermal stress analysis of PCB, even though these two models have similar heat transfer characteristics. The analysis results also show that the highest thermal stress occurs in the pin especially attached to the highest temperature chip, and the PCB constrained to the electronic package on the long side is structurally more stable than other cases. The analyses of the PCB are executed using the finite element analysis code, NISA.

An Analysis on the KSTAR neutral beam injection line (KSTAR 중성입자빔 수송라인 해석)

  • 임기학;김진춘;권경훈;조승연
    • Journal of the Korean Vacuum Society
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    • v.8 no.4B
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    • pp.556-564
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    • 1999
  • The analysis on heat fluxed on and transmission efficiencies by the collimators of neutral beam injection lines in KSTAR tokamak device has been carried out. And a mathematical model describing non-Gaussian beam distribution profile has been established. A neutral beam injection device is composed of 3 separate ion sources and corresponding beam transport lines, which deal with 7.8 MW of beam power, respectively. The divergence angles of ion beam are $1.2^{\circ}$and $0.5^{\circ}$, in vertical and horizontal directions, respectively. The maximum normal heat load on source exit scraper is 9.1 kW/$\textrm{cm}^2$ and net beam transmission efficiency is ~28%. The effect of misalignment of ion source and scrapers on the scraper heat load and beam transmission also has been analyzed.

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Heat and Flow Analysis on Cabin Room of Battle Tank (전차 포탑 승무원실의 내부 열/유동장에 관한 수치적 연구)

  • NamKoung, H.J.;Lee, K.H.;Park, B.H.;Roh, K.L.
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2 s.25
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    • pp.5-10
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    • 2006
  • The heavy thermal load to battle tanks can cause electronic components' malfunction and crew to be put out of action. The thermal load is generated from Internal heat sources such as electronic devices installed in the room as well as extremely hot weather. In this study, heat and flow analysis for the cabin room of a battle tank was performed to deal with this thermal problem. This study presented the validation of simulation results in comparison with those of test, the investigation of optimal flow design for effective cooling in cabin room and finally the evaluation of thermal comforts to crew.

A Study on the Operating Performance of Solar Assisted Hot Water System for Apartment Houses (공동주택용 태양열원 급탕시스템의 운전성능 연구)

  • 이윤규;황인주
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.11
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    • pp.928-936
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    • 2003
  • In the present study, feasibility investigation on the solar assisted hot water supply system for apartment houses was carried out by the review of service facility and heat load pattern. Also analysis and experiment of the small sized system model were performed. This hybrid system are consists of solar collector, heat storage tank, controller, and gas boiler using LPG as a secondary heat source. The analytical results showed a good agreement with experimental data. We found that this hybrid system could reduce the energy cost by 30% for hot water compared to typical boiler system in the apartment houses. Also we showed that this model could be used for the energy and economic analysis of the hybrid system.

Fire Behavior of Steel Columns Encased by Damaged Spray-applied Fire Resistive Material

  • Kwak, Yoon Keun;Pessiki, Stephen;Kwon, Kihyon
    • Architectural research
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    • v.10 no.1
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    • pp.1-11
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    • 2008
  • A Steel column with damaged spray-applied fire resistive material (SFRM) may exhibit reduced structural performance due to the effects of elevated temperature during fire events. Thus, the fire load behavior of steel columns with removed or reduced SFRM needs to be examined to predict the structural damage by fire. FEM analyses were performed for the flange thinning removal models in which the SFRM was reduced as a constant strip in thickness at the top flange of the column. The temperature results for all models obtained from the heat transfer analyses were included as an initial condition in the FEM structural analyses. In this study, the results of analysis show that even small remnants of SFRM led to an effective reduction of temperature at any given fire duration, and improved significantly the axial load capacity of a column as compared to the complete removal cases of SFRM.