• Title/Summary/Keyword: Temperature Calculation

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Intermittent Heating and Cooling Load Calculation Method -Comparing with ISO 13790

  • Lee, Sang-Hoon
    • Architectural research
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    • v.14 no.1
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    • pp.11-18
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    • 2012
  • College of Architecture, Georgia Institute of Technology, Atlanta, GA, US Abstract The intermittent heating and cooling energy need calculation of the ISO 13790 monthly method was examined. The current ISO 13790 method applies a reduction factor to the continuous heating and cooling need calculation result to derive the intermittent heating and cooling for each month. This paper proposes a method for the intermittent energy need calculation based on the internal mean temperature calculation. The internal temperature calculation procedure was introduced considering the heat-balance taking into account of heat gain, heat loss, and thermal inertia for reduced heating and cooling period. Then, the calculated internal mean temperature was used for the intermittent heating and cooling energy need calculation. The calculation results from the proposed method were compared to the current ISO 13790 method and validated with a dynamic simulation using EnergyPlus. The study indicates that the intermittent heating and cooling energy need calculation method using the proposed model improves transparency of the current ISO 13790 method and draws more rational outcomes in the monthly heating and cooling energy need calculation.

A Calculation Method for Temperature Distribution of Hot Water Pipe under Unsteady Condition (비정상조건하의 온수배관의 온도분포에 관한 수치계산법 연구)

  • Choi, C.H.;Suh, S.J.
    • Solar Energy
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    • v.19 no.3
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    • pp.13-21
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    • 1999
  • Calculation method about the water temperature variable inside hot water pipe had proposed in the past does not correspond with branch pipe system, variable of water volume, variable of entrance water temperature, using and so on. A calculation method proposed in this paper can solve above problems, and calculate the kinds variation of the water temperature inside pipe in the real use state of the hot water pipe.

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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.

Developments of a Cross-Correlation Calculation Algorithm for Gas Temperature Distributions Based on TDLAS (레이저흡수분광법(TDLAS) 기반 가스온도분포 산정을 위한 상호상관계산 알고리듬 개발)

  • CHOI, DOOWON;KIM, KWANGNAM;CHO, GYONGRAE;SHIM, JOONHWAN;KIM, DONGHYUK;DEGUCHI, YOSHIHIRO;DOH, DEOGHEE
    • Journal of Hydrogen and New Energy
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    • v.27 no.1
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    • pp.127-134
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    • 2016
  • Most of reconstruction algorithms for the calculation of temperature distributions in CT (computed tomography)-TDLAS (tunable diode laser absorption spectroscopy) are based upon two-line thermometry method. This method gives unstable calculation convergence due to signal noise, bias error, and signal mis-matches. In this study, a new reconstruction algorithm based on cross-correlation for temperature calculation is proposed. The patterns of the optical signals at all wave lengths were used to reconstruct the temperature distribution. Numerical test has been made using phantom temperature distributions. Using these phantom temperature data, absorption spectra for all wave lengths were constructed, and these spectra were regarded as the signals that would be obtained in an actual experiments. Using these virtually generated experimental signals, temperature distribution was once again reconstructed, and was compared with those of the original phantom data. Calculation errors obtained by the newly proposed algorithm were slightly large at high temperatures with small errors at low temperature.

A Study on the Safe Maneuvering Technology Based on the Thermal Calculation of Membrane Type LNG Carrier (멤브레인형 LNGC의 열계산에 기초한 안전운항기술에 관한 연구)

  • Jin, Chang-Fu;Kim, Kyung-Kuen;Oh, Cheol
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.8
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    • pp.1192-1200
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    • 2008
  • This paper is concerned with the thermal design of the $138,000m^3$ class membrane type LNGC. To predict the temperature distribution, BOG and BOR, 3-dimensional numerical calculation was carried-out for the quarter of No.3 LNG tank. These sequence analyses were performed under the standard conditions of IMO ship design condition, USCG ship design condition and the Korean flag LNGC's route condition according to the 6-voyage modes. As the results, temperature behavior, heat flux, total penetrating heat, BOG and BOR were obtained, and those were compared with the maneuvering results considering the real temperature variation of air and sea water temperature at noon time. For securing the safety of LNGC during the ballast voyage, optimum control patterns of pressure and temperature in LNG tank is suggested in this paper.

Improvement of the Conductor Temperature Calculation Algorithm for Calculating the Allowable Current in the Underground Channel (지중관로에서의 실제 허용전류 산출을 위한 도체온도 계산 알고리즘 개선에 관한 연구)

  • Lee, Hyang-Beom;Lee, Byung-Chul;Kim, Jung-Hoon;Nam, Yong-Hyun;Kang, Ji-Won
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.3
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    • pp.352-357
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    • 2018
  • In this paper, the improvement of the conductor temperature calculation algorithm is studied. The allowable current of the underground transmission line is determined by the conductor temperature limit. Usually to calculate the allowable current limit, the conductor temperature is assumed in the most worst environment condition. It is possible to increase the transmission capacity if the actual burial environment is considered. Therefore, in this paper an algorithm is proposed to calculate the conductor temperature by distinguishing two area of a underground transmission line condition - the manhole where the temperature sensor can be installed and the underground transmission line in which the temperature sensor can not be installed easily. When calculating the conductor temperature by the underground line in the pipeline, the existing standard describes each environment as a single soil heat resistance and one ambient temperature. In order to compensate this situation, thermal resistance model that can take into consideration the ground surface temperature and under ground temperature is proposed. It is shown that the accuracy of the proposed model is increased compared with the existing standard calculation result.

A Evaluation of Calculation Method for Temperature Distribution of Hot Water Pipe with Changing Flow Rate (유량변화를 고려한 온수배관의 온도분포 계산법평가에 관한 연구)

  • Suh, S.J.;Choi, C.H.
    • Solar Energy
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    • v.19 no.3
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    • pp.53-61
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    • 1999
  • We already presented new calculation method about the temperature distribution in hot water pipe flow of the unsteady condition. In this paper, we introduce consequence of the case study to confirm appropriation of the calculation method, and case study performs to establish actual hot water use supposed two model that is; the CWV(constant water volume) and VWV(variable water volume).

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Hydrogen Supplying System using Metal Hydride (금속 수소화물을 이용한 수소공급시스템)

  • Bae, Sang-Chul;Katsuta, Masafumi
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.13-19
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    • 2007
  • To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1 MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristics, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results are compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

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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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Insights into fuel behaviour during relatively fast thermal transients based on calculations for two tests of the Halden IFA-507 experiment

  • Grigori Khvostov
    • Nuclear Engineering and Technology
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    • v.55 no.10
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    • pp.3801-3807
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    • 2023
  • Outcomes of the project "Comprehensive Verification of the FALCON Code for Calculation of Nuclear Fuel Temperature" relating to calculation of fuel temperature during relatively fast thermal transients are presented. Good prediction capabilities of the FALCON MOD01 code coupled with the GRSW-A code are shown as applied to the data of the TF3 and TF5 tests from the Transient Temperature Experiment IFA-507. The IFA-507 related dataset of the OECD/NEA International Fuel Performance Experiments (IFPE) Database is extended by the reconstructed dynamics of the axial power distribution in the rods during the transient phase of the experiment. Based on the code calculation, the time constant of the thermal fuel response to a power transient is estimated.