Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers

The spiral tube heat exchanger has the advantages of stable structure, high space utilization rate, and strong heat transfer ability. Supercritical carbon dioxide (s-CO<sub>2</sub>) has the advantages of high thermal conductivity, high specific heat capacity, and low viscosity. When the...

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Main Authors: Jian Cheng, Wendong Wang, Jianyang Yu, Huadong Jiang, Jianmin Gao, Dan Xu
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/17/23/5960
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author Jian Cheng
Wendong Wang
Jianyang Yu
Huadong Jiang
Jianmin Gao
Dan Xu
author_facet Jian Cheng
Wendong Wang
Jianyang Yu
Huadong Jiang
Jianmin Gao
Dan Xu
author_sort Jian Cheng
collection DOAJ
description The spiral tube heat exchanger has the advantages of stable structure, high space utilization rate, and strong heat transfer ability. Supercritical carbon dioxide (s-CO<sub>2</sub>) has the advantages of high thermal conductivity, high specific heat capacity, and low viscosity. When the spiral tube heat exchanger uses supercritical carbon dioxide as the heat transfer medium, the two complement each other’s advantages and can further improve the heat transfer efficiency and optimize the space utilization rate. However, under the coupling influence of factors such as centrifugal force and buoyancy force, the heat transfer process of s-CO<sub>2</sub> in the spiral tube is extremely complex. At present, there is no design criterion or empirical correlation with strong universality in the industrial field. Based on this, this paper mainly uses ANSYS FLUENT, a numerical simulation software suitable for numerical simulation, to study the influence of internal vortex field and secondary flow intensity on the thickness of thermal boundary layers through a combination of numerical simulation and theoretical analysis. At the same time, by changing various operating and structural parameters, the heat transfer characteristics of supercritical s-CO<sub>2</sub> in the spiral tube heat exchanger are analyzed and summarized. In addition, we also established a new buoyancy factor, <i>Fu</i>, and tested that when Fu < 1.6 × 10<sup>−5</sup>, the effect of the buoyancy lift in the pipeline disappeared. At the same time, a correlation formula for predicting the heat transfer performance of spiral tube heat exchangers with a Nu number error less than 20% is established in this paper, which can provide solid theoretical guidance for industrial application.
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spelling doaj-art-0e7b58eef0fe46c2b8e86bfec1ea59542025-08-20T02:38:36ZengMDPI AGEnergies1996-10732024-11-011723596010.3390/en17235960Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat ExchangersJian Cheng0Wendong Wang1Jianyang Yu2Huadong Jiang3Jianmin Gao4Dan Xu5School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150006, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150006, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150006, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150006, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150006, ChinaStrategic Assessments and Consultation Institute of AMS, Beijing 100000, ChinaThe spiral tube heat exchanger has the advantages of stable structure, high space utilization rate, and strong heat transfer ability. Supercritical carbon dioxide (s-CO<sub>2</sub>) has the advantages of high thermal conductivity, high specific heat capacity, and low viscosity. When the spiral tube heat exchanger uses supercritical carbon dioxide as the heat transfer medium, the two complement each other’s advantages and can further improve the heat transfer efficiency and optimize the space utilization rate. However, under the coupling influence of factors such as centrifugal force and buoyancy force, the heat transfer process of s-CO<sub>2</sub> in the spiral tube is extremely complex. At present, there is no design criterion or empirical correlation with strong universality in the industrial field. Based on this, this paper mainly uses ANSYS FLUENT, a numerical simulation software suitable for numerical simulation, to study the influence of internal vortex field and secondary flow intensity on the thickness of thermal boundary layers through a combination of numerical simulation and theoretical analysis. At the same time, by changing various operating and structural parameters, the heat transfer characteristics of supercritical s-CO<sub>2</sub> in the spiral tube heat exchanger are analyzed and summarized. In addition, we also established a new buoyancy factor, <i>Fu</i>, and tested that when Fu < 1.6 × 10<sup>−5</sup>, the effect of the buoyancy lift in the pipeline disappeared. At the same time, a correlation formula for predicting the heat transfer performance of spiral tube heat exchangers with a Nu number error less than 20% is established in this paper, which can provide solid theoretical guidance for industrial application.https://www.mdpi.com/1996-1073/17/23/5960spiral tube heat exchangersupercritical carbon dioxidebuoyancy criterionheat transfer correlation
spellingShingle Jian Cheng
Wendong Wang
Jianyang Yu
Huadong Jiang
Jianmin Gao
Dan Xu
Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
Energies
spiral tube heat exchanger
supercritical carbon dioxide
buoyancy criterion
heat transfer correlation
title Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
title_full Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
title_fullStr Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
title_full_unstemmed Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
title_short Research of Heat Transfer Characteristics of Supercritical CO<sub>2</sub> in Spiral Tube Heat Exchangers
title_sort research of heat transfer characteristics of supercritical co sub 2 sub in spiral tube heat exchangers
topic spiral tube heat exchanger
supercritical carbon dioxide
buoyancy criterion
heat transfer correlation
url https://www.mdpi.com/1996-1073/17/23/5960
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AT jianyangyu researchofheattransfercharacteristicsofsupercriticalcosub2subinspiraltubeheatexchangers
AT huadongjiang researchofheattransfercharacteristicsofsupercriticalcosub2subinspiraltubeheatexchangers
AT jianmingao researchofheattransfercharacteristicsofsupercriticalcosub2subinspiraltubeheatexchangers
AT danxu researchofheattransfercharacteristicsofsupercriticalcosub2subinspiraltubeheatexchangers