Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers

This report presents both experimental findings to validate the efficacy of heat transfer enhancement techniques of a novel air-cooled heat exchanger, as well as simulation findings to evaluate the heat transfer performance of a novel micro-channel design. On the experimental front, experiments wer...

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Main Author: Goh, Chok Khai
Other Authors: Leong Kai Choong
Format: Final Year Project
Language:English
Published: Nanyang Technological University 2024
Subjects:
Online Access:https://hdl.handle.net/10356/177673
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spelling sg-ntu-dr.10356-1776732024-06-08T16:50:19Z Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers Goh, Chok Khai Leong Kai Choong Wong Teck Neng School of Mechanical and Aerospace Engineering MKCLEONG@ntu.edu.sg, MTNWONG@ntu.edu.sg Engineering This report presents both experimental findings to validate the efficacy of heat transfer enhancement techniques of a novel air-cooled heat exchanger, as well as simulation findings to evaluate the heat transfer performance of a novel micro-channel design. On the experimental front, experiments were conducted on a novel air-cooled heat exchanger which was manufactured using selective laser melting (SLM). It consisted of porous P-cell lattice structures on the air-side, and triangular multiport channels on the refrigerant-side. The two-phase performance of the refrigerant-side multiport channels was characterised. Two mass fluxes, 45 kg/m2 ⋅ s and 80 kg/m2 ⋅ s were conducted to investigate the heat transfer coefficient and pressure drop values against the average vapour quality of the micro-channel. For the heat transfer coefficient, while the overall range of values obtained were in line with literature, the trend of an increasing heat transfer coefficient with an increase in average vapour quality was not observed. For the pressure drop of the refrigerant, the higher mass flux of 80 kg/m2 ⋅ s showed a higher pressure drop than that of the lower mass flux of 45 kg/m2 ⋅ s. On the numerical front, a new micro-channel was designed, consisting of a cross-finned and twisted tube setup. These enhancement methods were predicted to improve heat transfer performance through inducing turbulence as well as increased surface area-to-volume ratio. Three-dimensional two-phase simulations were conducted, using ANSYS Fluent, on this design, as well as a simple circular tube to validate the simulation setup. The simulation results were largely not in agreement with those found in the literatures, rendering the results to be highly unreliable. Bachelor's degree 2024-06-03T00:36:14Z 2024-06-03T00:36:14Z 2024 Final Year Project (FYP) Goh, C. K. (2024). Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/177673 https://hdl.handle.net/10356/177673 en application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering
spellingShingle Engineering
Goh, Chok Khai
Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
description This report presents both experimental findings to validate the efficacy of heat transfer enhancement techniques of a novel air-cooled heat exchanger, as well as simulation findings to evaluate the heat transfer performance of a novel micro-channel design. On the experimental front, experiments were conducted on a novel air-cooled heat exchanger which was manufactured using selective laser melting (SLM). It consisted of porous P-cell lattice structures on the air-side, and triangular multiport channels on the refrigerant-side. The two-phase performance of the refrigerant-side multiport channels was characterised. Two mass fluxes, 45 kg/m2 ⋅ s and 80 kg/m2 ⋅ s were conducted to investigate the heat transfer coefficient and pressure drop values against the average vapour quality of the micro-channel. For the heat transfer coefficient, while the overall range of values obtained were in line with literature, the trend of an increasing heat transfer coefficient with an increase in average vapour quality was not observed. For the pressure drop of the refrigerant, the higher mass flux of 80 kg/m2 ⋅ s showed a higher pressure drop than that of the lower mass flux of 45 kg/m2 ⋅ s. On the numerical front, a new micro-channel was designed, consisting of a cross-finned and twisted tube setup. These enhancement methods were predicted to improve heat transfer performance through inducing turbulence as well as increased surface area-to-volume ratio. Three-dimensional two-phase simulations were conducted, using ANSYS Fluent, on this design, as well as a simple circular tube to validate the simulation setup. The simulation results were largely not in agreement with those found in the literatures, rendering the results to be highly unreliable.
author2 Leong Kai Choong
author_facet Leong Kai Choong
Goh, Chok Khai
format Final Year Project
author Goh, Chok Khai
author_sort Goh, Chok Khai
title Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
title_short Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
title_full Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
title_fullStr Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
title_full_unstemmed Enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
title_sort enhancement of refrigerant-side condensation heat transfer performance of additively-manufactured air-cooled heat exchangers
publisher Nanyang Technological University
publishDate 2024
url https://hdl.handle.net/10356/177673
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