• Title/Summary/Keyword: Temperature profile

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Experimental study on TDLAS temperature profile measurement using temperature binning method (TDLAS에서 temperature binning 방법을 이용한 온도 측정에 대한 실험적 연구)

  • Yoon, Sungwoon;Kim, Sewon;Shin, Myungchul;Lee, Changyeop
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.27-28
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    • 2012
  • Tunable diode laser absorption spectroscopy(TDLAS) measurement techniques for several gases densities and temperatures have been applied in industrial combustion systems. Accurate measurement of temperature profile is very important, especially in power plants and heating furnaces. So profile fitting and temperature binning methods are new issue for accurate measurement of temperature in laser gas sensing. Temperature binning method is applied in this study for the measurement of temperature profile using tube furnace with three temperature zones. In this study the temperature profiles of tube furnace is accurately measured within 5% error, and this technique is proved to be very promising in the field of temperature profile measurement.

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A Study on the Stack Temperature Profile of a Standing Wave Thermoacoustic Cooler (정재파 열음향 냉각기의 스택 온도구배에 대한 연구)

  • Paek, In-Su
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.1
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    • pp.19-24
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    • 2009
  • Investigations of the relation between the stack temperature profile of a standing wave thermoacoustic cooler and the cooling efficiency were performed. Based on the mathematical derivations using the Rott Equation, it was found that the temperature profile along the stack becomes nonlinear as the enthalpy flux passing through the stack increases. It was also found that such nonlinear temperature profiles lower the cooling efficiency. Simulations using a thermoacoustic simulation program called DELTAE showed that the nonlinear temperature profile occurs with a long stack and large cooling load.

Effect of Process Condition on Tensile Properties of Carbon Fiber

  • Lee, Sung-Ho;Kim, Ji-Hoon;Ku, Bon-Cheol;Kim, Jun-Kyong;Chung, Yong-Sik
    • Carbon letters
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    • v.12 no.1
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    • pp.26-30
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    • 2011
  • For polyacrylonitrile (PAN) based carbon fiber (CF) process, we developed a lab scale wet spinning line and a continuous tailor-made stabilization system with ten columns for controlling temperature profile. PAN precursor was spun with a different spinning rate. PAN spun fibers were stabilized with a total duration of 45 to 110 min at a given temperature profile. Furthermore, a stabilization temperature profile was varied with the last column temperature from 230 to $275^{\circ}C$. Stabilized fibers were carbonized in nitrogen atmosphere at $1200^{\circ}C$ in a furnace. Morphologies of spun and CFs were observed using optical and scanning electron microscopy, respectively. Tensile properties of resulting CFs were measured. The results revealed that process conditions such as spinning rate, stabilization time, and temperature profile affect microstructure and tensile properties of CFs significantly.

Calculation of fuel temperature profile for heavy water moderated natural uranium oxide fuel using two gas mixture conductance model for noble gas Helium and Xenon

  • Jha, Alok;Gupta, Anurag;Das, Rajarshi;Paraswar, Shantanu D.
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2760-2770
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    • 2020
  • A model for calculation of fuel temperature profile using binary gas mixture of Helium and Xenon for gap gas conductance is proposed here. In this model, the temperature profile of a fuel pencil from fuel centreline to fuel surface has been calculated by taking into account the dilution of Helium gas filled during fuel manufacturing due to accumulation of fission gas Xenon. In this model an explicit calculation of gap gas conductance of binary gas mixture of Helium and Xenon has been carried out. A computer code Fuel Characteristics Calculator (FCCAL) is developed for the model. The phenomena modelled by FCCAL takes into account heat conduction through the fuel pellet, heat transfer from pellet surface to the cladding through the gap gas and heat transfer from cladding to coolant. The binary noble gas mixture model used in FCCAL is an improvement over the parametric model of Lassmann and Pazdera. The results obtained from the code FCCAL is used for fuel temperature calculation in 3-D neutron diffusion solver for the coolant outlet temperature of the core at steady operation at full power. It is found that there is an improvement in calculation time without compromising accuracy with FCCAL.

Dynamic Characteristics of Thermal Stratification Build-up by Unsteady Natural Convection (비정상 자연대류에 의한 온도성층화의 동특성에 관한 연구)

  • Kang, B.S.;Lee, J.S.;Lee, T.S.;Ro, S.T.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.17 no.4
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    • pp.382-394
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    • 1988
  • Dynamic characteristics of thermally-forced stratification process in a square enclosure with a linear temperature profile at the side walls have been investigated through flow visualization experiment and numerical analysis. The experiment was performed on air with the Rayleigh numbers of order $10^5$. A particle tracer method is used for the flow visualization and to obtain a sudden linear temperature profile at the side walls copper blocks which already have a linear temperature profile are come into contact with the thin copper plates of the test section. Immediately a meridional circulation is developed and heat transfer takes place from the wall to the interior region by circulation of fluid and finally a thermal stratification is achieved. In the numerical study, QUICK scheme for convective terms, SIMPLE algorithm for pressure correction, and the implicit method for the time marching are adopted for the integration of conservation equations. Comparison of flow visualization and numerical results shows that the developing flow patterns are very similar in dynamic nature even though there is a time lag due to the inevitable time delay in setting up a linear temperature profile. For high Rayleigh numbers, the oscillatory motion is likely to take place and stratified region is extended. However, initial temperature adjustment process is much slower than that for low Rayleigh numbers.

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Measurement System of the Transverse Temperature Profile of Hot Rolled Strip (열간압연공정에서의 스트립 폭방향온도 모니터링시스템 개발)

  • Lee, Sung-Jin
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.197-201
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    • 2001
  • Output and cost efficiency in the production of hot-rolled strip depend to a large content on the uniformity of geometric and mechanical properties over the length and width of the rolled end product. To ensure the homogeneous temperatures required for this during the rolling process a system to measure and evaluate the transverse temperature profile was developed and implemented in production. The systems used consist of temperature scanners and computers for measurement and data evaluation. The systems have been installed in Kwangyang hot strip mills, in the cases at the exit of the finishing train and at the entry of the coiler. They are used in production to determine the effect of the finishing train and the cooling zone on the technological properties of the hot rolled strip.

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Study on Coherent Anti-Stokes Raman Spectroscopy for Measuring Temperature Profile in a Flame (CARS를 이용한 화염내부 온도분포 측정연구)

  • 한재원;박승암;이은성;이충희;강경태;정석호
    • Korean Journal of Optics and Photonics
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    • v.3 no.4
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    • pp.266-272
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    • 1992
  • A coherent anti-Stokes Raman spectroscopy (CARS) technique is applied to measure temperature profile in a flame. The CARS signal is obtained with BOXCARS phase matching to get better spatial resolution. A program routine for calculating temperature of the flame from the measured CARS spectra is studied. The routine includes the line broadening mechnism of the molecules described with a modified energy gap (MEG) law by using the perturbation theory. We have found that the temperature profile obtained with the MEG law is properly fit with the results measured with a thermocoulpe and calculated with the adiabatic theory.

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A Calculation Model for Fuel Constituent Redistribution and Temperature Distribution on Metallic U-10Zr Fuel Slug of Liquid Metal Reactors

  • Nam, Cheol;Hwang, Woan
    • Nuclear Engineering and Technology
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    • v.30 no.6
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    • pp.507-517
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    • 1998
  • Unlike conventional fuel types, fuel constituent redistribution and sodium intrusion into the fuel slug are the unique phenomena of the irradiated metallic fuel. A thermal calculation model on metallic U-10 wt.%Zr fuel rod for LMRs is developed with considerations given to these phenomena. The amount of constituent redistribution is estimated based on the thermotransport process. The temperature profile of fuel slug is predicted by taking into account of Zr redistribution, porosity formation and sodium logging effects. A sample calculation is performed and compared to experimental data in literature. As a result, the predicted redistribution and temperature profile are well agreed with experimental data, assuming that 15 times increment of ex-reactor diffusivity, $Q_{r}$ $^{*}$ is -50 kJ/mole and sodium is infiltrated only outside of the fuel slug. Furthermore, the redistribution effects on fuel integrity and fuel temperature profile are discussed.d.

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Inverse Problem of Determining Unknown Inlet Temperature Profile in Two Phase Laminar Flow in a Parallel Plate Duct by Using Regularization Method (조정법을 이용한 덕트 내의 이상 층류 유동에 대한 입구 온도분포 역해석)

  • Hong, Yun-Ky;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.9
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    • pp.1124-1132
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    • 2004
  • The inverse problem of determining unknown inlet temperature in thermally developing, hydrodynamically developed two phase laminar flow in a parallel plate duct is considered. The inlet temperature profile is determined by measuring temperature in the flow field. No prior information is needed for the functional form of the inlet temperature profile. The inverse convection problem is solved by minimizing the objective function with regularization method. The conjugate gradient method as iterative method and the Tikhonov regularization method are employed. The effects of the functional form of inlet temperature, the number of measurement points and the measurement errors are investigated. The accuracy and efficiency of these two methods are compared and discussed.

A study on the temperature distribution measurement of the high pressure mercury lamp (고압 수은등의 온도분포 측정에 대한 연구)

  • 손승현;김상용;김창섭;지철근
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1990.10a
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    • pp.35-40
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    • 1990
  • Temperature distribution of high pressure mercury lamp has been mesured as a function of time using spectroscopic method. Sampling signal which is synchronized by lamp voltage was used to mesure temporal line intensity at each radius. To obtain radial temprature distribution, the mesured intensity was transformed into radial line intensity by Abel's formula. Absolute temperature profile was calculater from relative intensities of spectral lines as a function of line and tube radius. The temperature profile is very similar to the electrical tube current profile.

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