• 제목/요약/키워드: Heat of reaction

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산업용 회분식 반응기에서의 반응열 추정 (Reaction heat estimation of industrial batch reactors)

  • 방성호;이대욱;이광순;이석호;손종상;윤상철
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.595-600
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    • 1993
  • The heat of reaction has been estimated from heat balance relationships around the reactor. The heat balance equations were formulated with the assumptions that the reactor temperature is uniformly distributed and the jacket temperatures are axially distributed. We have obtained the temperature distribution of jacket contents by FDM. And then, we have rearranged the heat balance equations so that the heat of reaction can be estimated from the finite number of temperature measurements, i.e., temperatures of the reactor contents, at the jacket inlet and outlet, respectively. The proposed method for reaction heat estimation on were applied to industrial batch reactors ; one is ABS polymerization reactor and the other is SAN polymerization reactor. We have also examined the variation of overall heat transfer coefficients for the reactors during reaction.

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$Ca(OH)_2/CaO$ 계의 가역 열화학 반응열을 이용한 축열식 열교환기의 축열 및 방열특성에 관한 연구 (A Study on the Heat-Storage/-Release Characteristics of a Regenerative Heat Exchanger Utilizing the Reversible Thermochemical Reaction of $Ca(OH)_2/CaO$)

  • 이수각;김홍제;이진국
    • 태양에너지
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    • 제9권2호
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    • pp.22-30
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    • 1989
  • Since the energy storage method by means of the thermochemical reaction has no heat loss by separating the reactants under the storage period, it is remarked as one of promising means particularly for long-term heat storage. In this study, the heat-storage/-release characteristics of the reversible chemical reaction cycle, $Ca(OH)_2/CaO$, is numerically analysed by a mathematical modelling. As a result, the effectiveness of the heat exchanger by the chemical heat storage method is considerably higher than that by the sensible heat storage method. It is found that the major parameters, which determines the effectiveness of the heat exchanger, are the mass flow rate and inlet temperature of fluid, the residence time, etc.. The heat-storage/-release period can be controlled by changing the operation conditions. It is expected that the results obtained here will supply useful informations in designing a regenerative heat exchanger utilizing the thermochemical reaction.

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소성조건에 따른 폐 벤토나이트의 포졸란 반응성에 관한 실험적 연구 - 주수냉각을 중심으로 - (An Experimental Study on the Pozzolan Reaction of discarded Bentonite by Heat Treatment Condition - Focused on discarded Bentonite by cooling using of Water -)

  • 장진봉;정민수;김효열;강병희
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2002년도 학술논문발표회
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    • pp.85-90
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    • 2002
  • This study aims to propose a fundamental report for pozzolan reaction of discarded Bentonite by heat-treatment as concrete mineral admixture. As discarded bentonite is clay mineral to contain a great quantity a lot of $SiO_2$ and $Al_{2}O_{3}$, it is anticipated to reveal pozzolan reaction ability by heat-treatment. To find out pozzolan reaction ability of discarded Bentonite slurry by heat-treatment, the experiment is excuted Phenolphtalein test, setting test, pH test and the analysis by X-ray diffractor. As a result of this study, discarded Bentonite slurry can be utilized as concrete mineral admixture by heat-treatment and especially, pozzolan reaction ability of discarded Bentonite slurry is superior to the situation of 50$0^{\circ}C$~$700^{\circ}C$, 60min.

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촉매 연소를 열원으로 한 수증기-메탄개질반응 전산유체해석 (Numerical Analysis of Steam-methane Reforming Reaction for Hydrogen Generation using Catalytic Combustion)

  • 이정섭;이강훈;유상석;안국영;강상규
    • 한국수소및신에너지학회논문집
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    • 제24권2호
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    • pp.113-120
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    • 2013
  • A steam reformer is a chemical reactor to produce high purity hydrogen from fossil fuel. In the steam reformer, since endothermic steam reforming is heated by exothermic combustion of fossil fuel, the heat transfer between two reaction zones dominates conversion of fossil fuel to hydrogen. Steam Reforming is complex chemical reaction, mass and heat transfer due to the exothermic methane/air combustion reaction and the endothermic steam reforming reaction. Typically, a steam reformer employs burner to supply appropriate heat for endothermic steam reforming reaction which reduces system efficiency. In this study, the heat of steam reforming reaction is provided by anode-off gas combustion of stationary fuel cell. This paper presents a optimization of heat transfer effect and average temperature of cross-section using two-dimensional models of a coaxial cylindrical reactor, and analysis three-dimensional models of a coaxial cylindrical steam reformer with chemical reaction. Numerical analysis needs to dominant chemical reaction that are assumed as a Steam Reforming (SR) reaction, a Water-Gas Shift (WGS) reaction, and a Direct Steam Reforming(DSR) reaction. The major parameters of analysis are temperature, fuel conversion and heat flux in the coaxial reactor.

회분식 반응열 분석 시스템의 개발과 응용 (Development and application of a batch reaction calorimeter)

  • 이기형;이대욱;정상태;이광순
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.947-952
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    • 1992
  • A batch reaction calorimeter is the device for estimating reaction heat along time. Reaction heat formation data are very imoprtant for batch reactor behavior analysis and operatoin. So, many types of reaction calorimeter have been introduced and used. In this study, we analyze the dynamic charateristics of the batch reaction calorimeter that is designed in our laboratory. And we introducde suitable temperature control system. As a result, we analyze reatin heat formation data obtained by simulation and introduce its application examples.

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화합물 합성반응 중 Fridel - Crafts Acylation 공정에서의 폭주반응 위험성평가 (The Risk Assessment of Runway Reaction in the Process of Fridel-Crafts Acylation for Synthesis Reaction)

  • 이광호;김원성;전진우;주영종;박교식
    • 한국안전학회지
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    • 제36권3호
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    • pp.24-30
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    • 2021
  • Heat is generated during the synthesis and mixing process of chemical compounds due to a change in activation energy during the reaction. A runaway reaction occurs when sufficient heat is not removed during the heat control process within a reactor, rapidly increasing the temperature, reaction speed, and rate of heat generation inside the reactor. A risk assessment was executed using an RC-1 (Reaction Calorimeter) during Friedel-Crafts acylation. Friedel-Crafts acylation runs the risk of rapid heat generation during Active Pharmaceutical Ingredient (API) manufacturing; it was used to confirm the risk of a runaway reaction at each synthesis stage and during the mixing process. This study used experimental data to develop a safety efficiency improvement plan to control the risks of runaway and other exothermic reactions, which was implemented at the production site of a chemical plant.

고리형 아민과 이산화탄소의 반응에서 온도와 흡수능이 반응열에 미치는 영향 (Effect on the Heat of Reaction to Temperature and Absorption Capacity in the Reaction of Cyclic Amines with Carbon Dioxide)

  • 최정호;장종탁;윤성희;조원희;정진영;윤여일
    • 한국수소및신에너지학회논문집
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    • 제29권5호
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    • pp.530-537
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    • 2018
  • The effect of temperature and absorption capacity on heat of reaction, which is one of the characteristic studies of $CO_2$ absorption, were investigated in a differential reaction calorimeter (DRC) by using piperazine (PZ) and 2-methylpiperazine (2-MPZ). For all absorbents, $CO_2$ loading capacity decreased with increasing the temperature, while the heat of reaction increased, it figured out that these had a linear correlation between $CO_2$ loading capacity and/or heat of reaction and the temperature. The heat of reaction of all absorbents increased with increasing $CO_2$ loading capacity, especially 2-MPZ rapidly increased at $70^{\circ}C$. The reason for increase in the heat of reaction was occurred the regeneration of $CO_2$, which is a reverse-reaction, simultaneously with the absorption.

Estimation of Heat and Rate Constant of Reaction by a Hight-Speed Isothermal Calorimeter

  • Jung, Heung-Joe;Ryu, Dong-Wan;Park, Chan-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.1873-1878
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    • 1991
  • An high-speed isothermal calorimeter which can trace the progress of a liquid phase reversible reaction was constructed using analog and digital computer. By means of a set point change of the calorimeter, the thermal energy capacity and the heat of reaction in reversible reaction mixture can be measured. The heat of reaction between 2-methyl furan and maleic anhydride and the heat capacities of the adduct were 61,200 J/mol and 2.38 J/ g K, respectively. Also reaction equilibrium constant and reaction rate constants can be estimated from the response curves of the calorimeter.

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MPS eutectic reaction model development for severe accident phenomenon simulation

  • Zhu, Yingzi;Xiong, Jinbiao;Yang, Yanhua
    • Nuclear Engineering and Technology
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    • 제53권3호
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    • pp.833-841
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    • 2021
  • During the postulated severe accident of nuclear reactor, eutectic reaction leads to low-temperature melting of fuel cladding and early failure of core structure. In order to model eutectic melting with the moving particle semi-implicit (MPS) method, the eutectic reaction model is developed to simulate the eutectic reaction phenomenon. The coupling of mass diffusion and phase diagram is applied to calculate the eutectic reaction with the uniform temperature. A heat transfer formula is proposed based on the phase diagram to handle the heat release or absorption during the process of eutectic reaction, and it can combine with mass diffusion and phase diagram to describe the eutectic reaction with temperature variation. The heat transfer formula is verified by the one-dimensional melting simulations and the predicted interface position agrees well with the theoretical solution. In order to verify the eutectic reaction models, the eutectic reaction of uranium and iron in two semi-infinite domains is simulated, and the profile of solid thickness decrease over time follows the parabolic law. The modified MPS method is applied to calculate Transient Reactor Test Facility (TREAT) experiment, the penetration rate in the simulations are agreeable with the experiment results. In addition, a hypothetical case based on the TREAT experiment is also conducted to validate the eutectic reaction with temperature variation, the results present continuity with the simulations of TREAT experiment. Thus the improved method is proved to be capable of simulating the eutectic reaction in the severe accident.

소성Dolomite 수화물계의 축열시스템에 관한 연구 - 소성Dolomite 탈수반응층의 전열해석 - (A Study on Heat Storage System Using Calcined Dolomite - Numerical Analysis of Heat Transfer in Calcined Dolomite Dehydration Packed Bed -)

  • 박영해;김종식
    • 한국태양에너지학회 논문집
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    • 제23권1호
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    • pp.29-38
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    • 2003
  • To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the material and heat transfer rate in the cylindrical bed reactor packed with Calcined Dolomite. Our results from the studies are as follows ; 1 The time needed to complete dehydration reaction at the wall side of the cylindrical reactor(r/rL=0.5) was shorter than that of the center(r/rL=0.0) as much as 12%. 2. Two dimensional (radial and circumferential) partial differential equations, concerning heat and mass transfer rate in the packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction in the cylindrical reactor. The solution reads rate of reaction in the packed bed reactor depends on the temperature and concentration of reactants. These results read the supplied heat transfers from the wall side of the cylinder to the center, dehydration reaction begins at the inner side of the wall of the cylindrical reactor and the dehydration reaction proceeds from the wall side to center of cylinder.