Heat Transfer Characteristics of the Steam Reformer in the HTTR Hydrogen Production System

12th International Conference on Nuclear Engineering, Volume 2 ◽

10.1115/icone12-49415 ◽

2004 ◽

Author(s):

Tetsuaki Takeda

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Hydrogen Production ◽

Production System ◽

Heat Transfer Performance ◽

Technology Development ◽

High Porosity ◽

Transfer Performance ◽

Metallic Wire ◽

Steam Reformer

A technology development of a hydrogen production system by nuclear heat is being performed as a heat application system of a high-temperature gas-cooled reactor in the Japan Atomic Energy Research Institute. The objectives of this study are to clarify the heat transfer performance of the steam reformer in the HTTR hydrogen production system and to obtain characteristics of heat transfer and pressure drop in a channel having metallic wire inserts with high porosity. A heat transfer experiment has been performed using a horizontal circular tube. It was found that the heat transfer performance of the method using the metallic wire inserts could be further improved under the high temperature conditions.

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Experimental Study on Application of Heat Transfer Enhancement Method Using Porous Material With High Porosity

Volume 3: Thermal Hydraulics; Current Advanced Reactors: Plant Design, Construction, Workforce and Public Acceptance ◽

10.1115/icone17-75060 ◽

2009 ◽

Author(s):

Tetsuaki Takeda ◽

Koichi Ichimiya

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Hydrogen Production ◽

Heat Transfer Enhancement ◽

Production System ◽

High Porosity ◽

Transfer Enhancement ◽

Steam Reformer ◽

Nuclear Heat ◽

Helium Gas

A technology development of a hydrogen production system by nuclear heat is being performed as a heat application system of the Very High Temperature Reactor (VHTR) in worldwide. As for the development of the coupling technology between the VHTR and the hydrogen production system, Japan Atomic Energy Agency had carried out a coupling technology test using a steam reforming process by natural gas. In the hydrogen production system by nuclear heat, the catalyst tube of the steam reformer is heated by the high temperature helium gas from the intermediate heat exchanger (IHX). There are several methods for heat transfer enhancement. For example, there are attaching various fins on the heat transfer surface, processing the surface roughly, and so on. Disk type fins are attached on the outside surface of the catalyst tube. The catalyst tube is inserted into the guide tube to increase an amount of heat transferred from the high temperature helium gas. However, it has to take into consideration the deterioration of the structure strength by attaching the fins on the tube surface with the design of the steam reformer. The objective of this study is to clarify performances of a method for heat transfer enhancement using porous material with high porosity by an experiment. The experiment has been performed using an apparatus which simulated the passage structure of the steam reformer to obtain characteristics of heat transfer.

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Convective heat transfer performance of thermal oil-based nanofluids in a high-temperature thermohydraulic loop

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2021.107243 ◽

2022 ◽

Vol 171 ◽

pp. 107243

Author(s):

Javier Gil-Font ◽

Nuria Navarrete ◽

Estefanía Cervantes ◽

Rosa Mondragón ◽

Salvador F. Torró ◽

...

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Convective Heat Transfer ◽

Convective Heat ◽

Heat Transfer Performance ◽

Transfer Performance ◽

Thermal Oil

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Thermo-Fluid Dynamic Design Exploration of a Double Pipe Heat Exchanger

Volume 2: Computational Fluid Dynamics ◽

10.1115/ajkfluids2019-4998 ◽

2019 ◽

Author(s):

Tomohiro Hirano ◽

Mitsuo Yoshimura ◽

Koji Shimoyama ◽

Atsuki Komiya

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Heat Transfer Performance ◽

Transfer Performance ◽

Nsga Ii ◽

Cross Sectional ◽

Average Temperature ◽

Double Pipe ◽

Sectional Shape ◽

Pipe Heat

Abstract Toward a practical application of the additive manufacturing (AM), this study proposes a shape optimization approach for the cross-sectional shape of the inner pipe of a counter-flow double pipe heat exchanger. The cross-sectional shape of the inner pipe is expressed by an algebraic expression with a small number of parameters, and their heat transfer performance is evaluated by a commercial Computational Fluid Dynamics (CFD) solver. The optimization is conducted by the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) assisted by the Kriging surrogate model, and the NSGA-II finds the optimal cross-sectional shape with many protrusions around the perimeter of the inner channel to improve the heat transfer performance. In this study, heat transfer performance is evaluated from the temperature drop at the outlet of the high-temperature fluid. Through the comparison of two cross-sectional shapes with the same heat transfer surface area — average temperature at the outlet of the optimal high-temperature channel is 324.58 K while average temperature at the outlet of a circular high-temperature channel with the same area as the optimal channel is 331.93 K, it is revealed that the number of protrusions plays important roles which contribute not only to increase heat transfer area but also to improve heat transfer performance.

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Heat Transfer Performance of Micro-Porous Copper Foams with Homogeneous and Hybrid Structures Manufactured by Lost Carbonate Sintering

MRS Proceedings ◽

10.1557/opl.2015.699 ◽

2015 ◽

Vol 1779 ◽

pp. 39-44 ◽

Cited By ~ 5

Author(s):

Jan Mary Baloyo ◽

Yuyuan Zhao

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Heat Transfer Performance ◽

Hybrid Structures ◽

High Porosity ◽

Transfer Performance ◽

Transfer Coefficients ◽

Heat Transfer Coefficients ◽

Porous Copper

ABSTRACTThe heat transfer coefficients of homogeneous and hybrid micro-porous copper foams, produced by the Lost Carbonate Sintering (LCS) process, were measured under one-dimensional forced convection conditions using water coolant. In general, increasing the water flow rate led to an increase in the heat transfer coefficients. For homogeneous samples, the optimum heat transfer performance was observed for samples with 60% porosity. Different trends in the heat transfer coefficients were found in samples with hybrid structures. Firstly, for horizontal bilayer structures, placing the high porosity layer by the heater gave a higher heat transfer coefficient than the other way round. Secondly, for integrated vertical bilayer structures, having the high porosity layer by the water inlet gave a better heat transfer performance. Lastly, for segmented vertical bilayer samples, having the low porosity layer by the water inlet offered the greatest heat transfer coefficient overall, which is five times higher than its homogeneous counterpart.

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Experimental Research of Heat Transfer Enhancement of the Tube with Disturbed Flow Components Plug-In

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.960-961.479 ◽

2014 ◽

Vol 960-961 ◽

pp. 479-484

Author(s):

Chang Fa Ji ◽

Rui Qu ◽

Guo Xin He

Keyword(s):

Heat Transfer ◽

Heat Transfer Performance ◽

Comprehensive Evaluation ◽

Orthogonal Experiment ◽

Metal Wire ◽

High Porosity ◽

Transfer Performance ◽

Enhancing Heat Transfer ◽

Flow Components ◽

The Given

Based on Field Synergy Principle and orthogonal experiment design, nine arranged metal-wire inserts(that is high porosity porous inserts) is determined to experiment. The results showed that heat transfer performance of the pipe that metal-wire inserts is rooted at the core region of pipe is better than the pipe that metal-wire inserts is rooted at the edge region of pipe., location and curve radian can impact heat exchange significantly. Under the given experimental condition, the heat transfer quantity increased by 120 - 520%, overall heat transfer coefficient increased by 126 - 610%. Through enhancing heat transfer performance evaluation criterion (PEC) comprehensive evaluation, it is concluded that when the Reynolds number Re changes in 338 ~ 6931, the PEC value of 0.89 ~ 5.97.The calculation formula of the drag coefficient is obtained by regression analysis.

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Heat Transfer Enhancement of Phase Change Materials (PCMs) in Low and High Temperature Thermal Storage by Using Porous Materials

2010 14th International Heat Transfer Conference, Volume 7 ◽

10.1115/ihtc14-22463 ◽

2010 ◽

Cited By ~ 12

Author(s):

C. Y. Zhao ◽

D. Zhou ◽

Z. G. Wu

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Phase Change ◽

Porous Materials ◽

Phase Change Materials ◽

Heat Transfer Performance ◽

Expanded Graphite ◽

Metal Foams ◽

Transfer Performance ◽

Solid Liquid

In this paper the solid/liquid phase change heat transfer in porous materials (metal foams and expanded graphite) at low and high temperatures is experimentally investigated, in an attempt to examine the feasibility of using metal foams to enhance the heat transfer capability of phase change materials for use with both the low and high temperature thermal energy storage systems. In this research, the organic commercial paraffin wax and inorganic hydrate calcium chloride hydrate salts were employed as the low-temperature materials, while the sodium nitrate is used as the high-temperature PCM in the experiment. The heat transfer characteristics of these PCMs embedded with open-cell metal foams were studied experimentally. The composites of paraffin and expanded graphite with different graphite mass ratios, namely, 3%, 6% and 9%, were also made and the heat transfer performances of these composites were tested and compared with metal foams. Overall metal foams can provide better heat transfer performance than expanded graphite due to their continuous inter-connected structures. But the porous materials can suppress the natural convection effect in liquid zone, particularly for the PCMs with low viscosities, thereby leading to the different heat transfer performance at different regimes (solid, solid/liquid and liquid regions). This implies that the porous materials don’t necessarily mean they can always enhance heat transfer in every regime.

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