Reduction of interior temperature of massive concrete using an enhanced heat transfer pipe array with spiral fins

2021 ◽  
pp. 136943322098862
Author(s):  
Lemu Zhou ◽  
Fangyuan Zhou ◽  
Zheng Peng ◽  
Hanbin Ge ◽  
Feng Shan
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Transfer Performance ◽  
Cooling Water ◽  
Element Model ◽  
Enhanced Heat Transfer ◽  
Massive Concrete ◽  
Concrete Blocks ◽  
Theoretical Results ◽  
The Finite Element Model

The interior temperature of the massive concrete should be controlled to avoid cracks caused by the trapped hydration heat. In this paper, an enhanced heat transfer pipe array with spiral fins (PSF) is proposed to reduce the interior temperature of concrete blocks. Numerical simulations of massive concrete blocks embedded with traditional cooling water pipe (TCWP) and newly proposed PSF were conducted to investigate the interior temperature distribution of massive concrete. Meanwhile, validity of the finite element model was verified by both theoretical results and available experimental data. Based on the calculated temperature distribution of the points located in the interior area of the massive concrete, it is shown that when the TCWP was replaced by the PSF, the interior temperature can be significantly reduced. Therefore, compared to the TCWP, the proposed PSF has excellent heat transfer performance for cooling the interior temperature of massive concrete.

scholarly journals Experimental study of heat transfer through cooling water circuit in a reactor vault by using Al2O3 nano fluid

2018 ◽  
Vol 22 (2) ◽  
pp. 1149-1161 ◽  
Author(s):  
Maria Anish ◽  
Balakrishnan Kanimozh
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Base Fluid ◽  
Nuclear Reactor ◽  
Characteristic Curve ◽  
Reactor Core ◽  
Cooling Water ◽  
Heat Transfer Process ◽  
Nano Fluid ◽  
Al2o3 Nanoparticle

The heat produced in the nuclear reactor due to fission reaction must be kept in control or else it will damage the components in the reactor core. Nuclear plants are using water for the operation dissipation of heat. Instead, some chemical substances which have higher heat transfer coefficient and high thermal conductivity. This experiment aims to find out how efficiently a nanofluid can dissipate heat from the reactor vault. The most commonly used nanofluid is Al2O3 nanoparticle with water or ethylene as base fluid. The Al2O3 has good thermal property and it is easily available. In addition, it can be stabilized in various PH levels. The nanofluid is fed into the reactor?s coolant circuit. The various temperature distribution leads to different characteristic curve that occurs on various valve condition leading to a detailed study on how temperature distribution carries throughout the cooling circuit. As a combination of Al2O3 as a nanoparticle and therminol 55 as base fluid are used for the heat transfer process. The Al2O3 nanoparticle is mixed in therminol 55 at 0.05 vol.% concentration. Numerical analysis on the reactor vault model was carried out by using ABAQUS and the experimental results were compared with numerical results.

Numerical study of heat transfer characteristics in positional wire and arc additive manufacturing

2020 ◽  
Vol 26 (9) ◽  
pp. 1627-1635
Author(s):  
Dongqing Yang ◽  
Jun Xiong ◽  
Rong Li
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Finite Element Model ◽  
Heat Dissipation ◽  
Element Model ◽  
Heat Transfer Characteristics ◽  
Content Type ◽  
Thin Walled

Purpose This paper aims to fabricate inclined thin-walled components using positional wire and arc additive manufacturing (WAAM) and investigate the heat transfer characteristics of inclined thin-walled parts via finite element analysis method. Design/methodology/approach An inclined thin-walled part is fabricated in gas metal arc (GMA)-based additive manufacturing using a positional deposition approach in which the torch is set to be inclined with respect to the substrate surface. A three-dimensional finite element model is established to simulate the thermal process of the inclined component based on a general Goldak double ellipsoidal heat source and a combined heat dissipation model. Verification tests are performed based on thermal cycles of locations on the substrate and the molten pool size. Findings The simulated results are in agreement with experimental tests. It is shown that the dwell time between two adjacent layers greatly influences the number of the re-melting layers. The temperature distribution on both sides of the substrate is asymmetric, and the temperature peaks and temperature gradients of points in the same distance from the first deposition layer are different. Along the deposition path, the temperature distribution of the previous layer has a significant influence on the heat dissipation condition of the next layer. Originality/value The established finite element model is helpful to simulate and understand the heat transfer process of geometrical thin-walled components in WAAM.

Bouyancy-Induced Convective Heat Transfer in Cylindrical Transformers Filled With Mineral Oil With Nano-Suspensions

2005 ◽  
Author(s):  
D. G. Walker ◽  
J. L. Davidson ◽  
P. G. Taylor ◽  
K. L. Soh ◽  
Bruce Rogers
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Mineral Oil ◽  
Transformer Oil ◽  
Experimental Measurements ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Enhanced Heat Transfer ◽  
Convective Flows ◽  
Good Agreement

The heat transfer characteristics of a transformer using both standard mineral oil and nanodiamond oil was investigated numerically and compared to experimental measurements. The results of the model agree well with the standard oil measurements and with theoretical convective flows from the literature. However, the simulations could not predict the magnitude of the temperature variation in the nanodiamond oil, although the appropriate trend was observed. Because properties of the nanodiamond transformer oil are not well known, good agreement is not expected. Nevertheless, nanodiamond in transformer oil shows enhanced heat transfer performance over standard transformer oil.

Research Progress of Three Kinds of Enhanced Heat Transfer Structures

2013 ◽  
Vol 711 ◽  
pp. 219-222
Author(s):  
Zhan Shu He ◽  
Xiao Long Liu ◽  
Xue Fei Yang
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Performance ◽  
Metal Foam ◽  
Porous Metal ◽  
Research Direction ◽  
Research Progress ◽  
Future Research ◽  
Transfer Performance ◽  
Enhanced Heat Transfer

In order to transfer heat as much as possible through a unit area in unit time, this paper introduces three enhanced heat transfer structures, namely microchannel, open-celled metal foam and open-celled sintered porous metal. From two aspects of the heat transfer performance and the flow resistance, this paper reviews their research progress. Among three kinds of enhanced heat transfer structures, open-celled sintered porous metal has the best heat transfer performance, followed by open-celled metal foam and micro-channel. While, the sequence of the pressure drop of three kinds of enhanced heat transfer structures is in the reverse order. Thus, Enhanced heat transfer Structures with good heat transfer performance and small pressure drop are the future research direction.

Comparison of Heat Transfer Performance Between Smooth and Enhanced Heat Transfer Tubes

2019 ◽  
Author(s):  
David J. Kukulka ◽  
Wei Li ◽  
Rick Smith
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
High Performance ◽  
Heat Transfer Performance ◽  
Industrial Applications ◽  
Material Surface ◽  
Transfer Performance ◽  
Enhanced Heat Transfer ◽  
Enhanced Tubes ◽  
Smooth Tubes

Abstract Heat transfer enhancement is an important factor in obtaining energy efficiency improvements in all heat transfer applications. A numeric study was performed that compares the performance of heat exchangers using the Vipertex enhanced heat transfer tubes (model 1EHT) to the performance of heat exchangers that use smooth surface tubes and other enhanced tubes. Surface enhancement of the 1EHT tube is accomplished through the use of the primary dimple enhancement and a secondary background pattern made up of petal arrays. Utilization of enhanced heat transfer tubes is an effective method that is utilized in the development of high performance thermal systems. Vipertex™ tubes, have been designed and produced through material surface modifications that produce flow optimized heat transfer tubes that increase heat transfer performance. Current energy demands and the desire to increase efficiencies of systems have prompted the development of optimized enhanced heat transfer surfaces. Enhanced heat transfer tubes are widely used in many areas (refrigeration, air-conditioning, process, petrochemical, chemical, etc.) in order to reduce cost, create a smaller application footprint or increase production. A new type of enhanced heat transfer tube has been created; therefore it is important to investigate relevant heat exchanger designs using the Vipertex enhanced surface tube in industrial applications and compare that performance to smooth tubes and other enhanced tubes. Results include design characteristics and performance predictions using the design simulations produced using HTRI Exchanger Suite (2016). Performance for all cases considered using the Vipertex tube predicted over design when compared to a smooth tube design. Vipertex 1EHT tubes produced enhanced heat transfer and cost efficient designs. In some of the case studies the 1EHT tubes produce an overdesign that is more than 35%, while smooth tubes produce an underdesign and other low fin tubes produce overdesign but not as large as the 1EHT tubes.

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