• Title/Summary/Keyword: 열변형 해석

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Effect of Process Gas and Burner Gas Temperature on Reaction and Thermal Deformation Characteristics in a Steam Reformer (증기 개질기의 반응 및 열변형 특성에 미치는 공정가스와 버너가스 온도의 영향)

  • Han, Jun Hee;Kim, Ji Yoon;Lee, Jung Hee;Lee, Seong Hyuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.126-132
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    • 2016
  • This study numerically investigates the characteristics of chemical reactions and thermal deformation in a steam reformer. These phenomena are significantly affected by the high-temperature burner gas and the process gas conditions. Because the high temperature of the burner gas ranges from 800 to 1000 K, the reformer tubes undergo substantial thermal deformation, eventually resulting in structural failure. Thus, it is necessary to understand the characteristics of the reaction and thermal deformation under the operating conditions to evaluate the reformer tubes for sustainable, stable operation. Extensive numerical simulations were carried out using commercial CFD code (ANSYS FLUENT/MECHANICA Ver. 13.0) while considering three-dimensional turbulent flows and combined heat transfer including conduction, convection, and radiation. Structural analysis considering conjugated heat transfer between solid tubes and fluid flows was conducted using the Fluid-Solid Interaction (FSI) method. The results show that when the injection temperature of the process gas and burner gas decreased, the hydrogen production rate decreased significantly, and thermal deformation decreased by at least 15 to 20%.

Thermal Analysis of Vacuum Cleaner Suction Nozzle Cover under Variable Conditions (다양한 조건하에서의 진공청소기 흡입구 커버의 열변형 해석)

  • Kang, Hyung-Seon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.973-978
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    • 2007
  • In this paper, we make a study of a thermal deformation by FEM and test to define the deformation mode of the Vacuum-Cleaner's Nozzle-Cover. In FEM analysis, 3 different conditions were considered separately, such as (1) Compressive force by Belt tension, (2) Friction heat between Belt and Shaft and (3) Compressive force combined with heat. Throughout FEM analysis it was found that the deformation was caused by heat and it was proved through a simulation test with a real product.

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A Study on Structural-Thermal-Optical Performance through Laser Heat Source Profile Modeling Using Beer-Lambert's Law and Thermal Deformation Analysis of the Mirror for Laser Weapon System (Beer-Lambert 법칙을 적용한 레이저 열원 프로파일 모델링 및 레이저무기용 반사경의 열변형 해석을 통한 구조-열-광학 성능 연구)

  • Hong Dae Gi
    • Journal of Aerospace System Engineering
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    • v.17 no.4
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    • pp.18-27
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    • 2023
  • In this paper, the structural-thermal-optical performance analysis of the mirror was performed by setting the laser heat source as the boundary condition of the thermal analysis. For the laser heat source model, the Beer-Lambert model considering semi-transparent optical material based on Gaussian beam was selected as the boundary condition, and the mechanical part was not considered, to analyze the performance of only the mirror. As a result of the thermal analysis, thermal stress and thermal deformation data due to temperature change on the surface of the mirror were obtained. The displacement data of the surface due to thermal deformation was fitted to a Zernike polynomial to calculate the optical performance, through which the performance of the mirror when a high-energy laser was incident on the mirror could be predicted.

Study on the prediction about thermal deformation of thin film solar cell according to metal substrates (금속기판재에 따른 박막형 태양전지의 열변형량 예측에 관한 연구)

  • Koo, Seung-Hyun;Lee, Heun-Yeol;Yim, Tai-Hong
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.285-288
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    • 2007
  • 박막형 태양전지 및 플렉서블 태양전지 기판으로 사용되는 금속기판의 우수성은 잘 알려져 있다. 그러나 상용 금속기판이 직면하고 있는 문제점을 보완하기 위해서 전주법으로 제조된 2원합금 금속포일을 개발하였으며, 박막형 및 플렉서블 태양전지의 기판재로 적용가능성을 확인하였다. 일반적으로 태양전지를 제조할 때 열 공정이 수행되며, 이때 기판재와 cell을 구성하는 반도체의 열팽창 계수 차이에 의한 열변형으로 결함이 발생될 수 있고, 태양전지 효율 및 수명을 저하시키는 원인이 될 수 있다. 이러한 원인이 될 수 있는 구성 재료간의 열팽창계수 차이에 의한 cell 의 변형량을 추정하기 위해 유한요소해석 방법을 사용하였다. 유한요소해석을 수행하기 위해 ALGOR 라는 해석 tool 을 사용하였다. 유한요소해석 수행에 사용된 상용 금속인 Mo, Ti, Al, SUS 포일과 전주법으로 제조된 2원합금 금속포일의 열팽창 계수는 실험을 통한 측정치이며, cell을 구성하는 반도체의 열팽창 계수와 열특성은 참고 문헌에 있는 자료들이다. 이 값들을 기반으로 cell 의 구성을 단순화시킨 가상의 태양전지가 제조 공정 온도에서 상온으로 냉각될 때의 열변형량을 계산하였다.

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The prediction of thermal deformation of Ni alloy substrate for application of flexible solar cell (플렉서블 태양전지 기판재용 Ni 계 합금의 열변형 예측)

  • Koo, Seung-Hyun;Lee, Heung-Yeol;Yim, Tai-Hong
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.382-385
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    • 2008
  • 박막형 태양전지 분야는 저가이고 가볍다는 특징을 가지고 있으며, 휘어지는 기판재를 적용하여 플렉서블 태양전지를 제조할 수도 있다는 장점을 가지고 있다. 본 연구에서 플렉서블 태양전지에 적합한 금속기판재를 제조하는 연구를 수행하였다. 일반적으로 기판재와 cell을 구성하는 반도체 층의 열팽창 거동 차이에 의한 열변형이 태양전지의 공정안정성에 영향을 주는 것으로 알려져 있었으며, cell을 구성하는 반도체 층과 열팽창 거동이 유사한 금속기판재의 적용이 필요하다. 이러한 특성을 쉽게 제어할 수 있는 금속기판재를 얇게 제조하기에 적절한 방법은 전주법이다. 전주법을 적용하여 조성 및 두께가 다른Ni 계 합금의 열팽창 거동을 TMA 장비를 사용하여 측정하였으며, 태양전지 제조에 사용되는 고온공정시 안정성 확보를 위하여 열처리후에 금속기판재의 열팽창 거동을 측정하였다. 그리고 전산해석tool 을 활용하여 가상의 CIS 플렉서블 태양전지 제조공정을 설정하고 고온공정온도에서 상온으로 냉각시 발생되는 층간 열변형 연구를 수행하였다. 그리고 플렉서블 태양전지용 기판재로 Ni 계 합금표면에 절연체인 $SiO_2$ 증착 연구를 수행하여 Fe-52Ni 합금에서 안정적인 절연층을 얻을 수 있었다.

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The Effect of Finite Element Models in Thermal Analysis of Electronic Packages (반도체 패키지의 열변형 해석 시 유한요소 모델의 영향)

  • Choi, Nam-Jin;Joo, Jin-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.4
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    • pp.380-387
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    • 2009
  • The reliability concerns of solder interconnections in flip chip PBGA packages are produced mainly by the mismatch of coefficient of thermal expansion(CTE) between the module and PCB. Finite element analysis has been employed extensively to simulate thermal loading for solder joint reliability and deformation of packages in electronic packages. The objective of this paper is to study the thermo-mechanical behavior of FC-PBGA package assemblies subjected to temperature change, with an emphasis on the effect of the finite element model, material models and temperature conditions. Numerical results are compared with the experimental results by using $moir{\acute{e}}$ interferometry. Result shows that the bending displacements of the chip calculated by the finite element analysis with viscoplastic material model is in good agreement with those by $moir{\acute{e}}$ inteferometry.

Measurement of Thermal Deformation of a Double Ring Structure using Digital Image Correlation Technique (디지털 영상 보정 기법을 이용한 이중 링 구조물의 열변형 측정)

  • Jin, Tailie;Goo, Nam-Seo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.9
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    • pp.877-882
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    • 2011
  • In this paper, thermal deformation of a double ring structure using digital image correlation technique (DIC) was measured. The double ring structure consisted of two parts; the inner ring was aluminium which had a large thermal expansion coefficient and the outer ring was titanium which had a small thermal expansion coefficient. We heated the double ring structure from $50^{\circ}C$ to $200^{\circ}C$ in a chamber and at the same time, two cameras captured surface images of the double ring structure. Initially, there was a 21 ${\mu}m$ gap between the inner ring and outer ring. The gap was closed at around $80^{\circ}C$ and after that, two rings expanded together. In order to compare the experimental results with analysis results, a finite element analysis was performed using ANSYS. The results of DIC measurement and ANSYS analysis were compared and agreed well.

A Study on the Verifying Structural Safety of Satellite Structure by Coupled Load Analysis (열변형으로 인한 인공위성 관측장비 지향오차 연구)

  • Kim, Sun-Won;Hyun, Bum-Seok;Kim, Chang-Ho;Hwang, Do-Soon
    • Journal of Satellite, Information and Communications
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    • v.5 no.1
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    • pp.75-79
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    • 2010
  • Satellite structure is distorted by thermal load in orbit. The structural distortion induces the pointing errors of observation unit that is difference between initial pointing direction at ground integration and at in-orbit. In that case, satellite is not able to point along required direction. As observation capability becomes higher, structural distortion due to thermal load should be smaller to achieve successful mission. In this paper, the method to predict pointing error and results are described.

Thermal Deformation Measurement of Notched Structure Using Global-local Multi-DIC System (전역-국부 다중 DIC 시스템을 이용한 노치 구조물의 열변형 계측)

  • Xin, Ruihai;Doan, Nguyen Vu;Goo, Nam Seo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.8
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    • pp.617-626
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    • 2021
  • During supersonic flight of vehicles, the thermal behavior of structures under high-temperature environment is important for thermal-structural design. In this study, full-field thermal deformation and stress concentration of the notched structure was performed using global-local multi-digital image correlation (multi-DIC) systems. This techniques were developed and implemented by multi-DIC systems consists of 2D DIC system and 3D DIC system. The specimen was heated in a heating chamber to achieve the thermal expansion behavior. Then the images of structure's deformation and stress concentration at various temperature were recorded and analyzed by multi-DIC system. Afterward, full-field thermal deformation of the notched structure was determined with DIC technique and stress concentration at the notched structure was calculated by further processing. Finite element analysis of the notched structure is performed in ABAQUSTM and the results of the experiments show good agreement with those obtained from simulation. The results achieved in this study show the efficiency of the muilti-DIC method in thermal deformation as well as stress concentration of notched structure.