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Cited by 6Heat Transfer and OptimizationRefrigeration and Air Conditioning TechnologiesHeat Transfer and Boiling Studies

Performance Improvement of Microchannel Heat Exchangers with Modified Louver Fins under Frosting Conditions

Open access
Xiong, Tong, Liu, Guoqiang, Yan, Gang·2023·Applied Sciences
DOI 10.3390/app13116378
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Abstract

Microchannel heat exchangers (MCHX) are increasingly being used in refrigeration and heat pumps due to their superior thermal-hydraulic properties. However, when the MCHX surface temperature drops below the freezing point, frost will accumulate on the fin surface, which significantly affects the heat transfer performance. In this study, a modified MCHX with extended windward fins was developed to improve the frosting performance. The thermal-hydraulic performance of the modified MCHX and conventional MCHX were compared and evaluated under frosting conditions. Results show that the extended fins on the windward side capture a large amount of frost and delay the rapid blockage of air flow passage by frost. The modified MCHX structure makes the frost more evenly distributed. During the 60 min frosting cycle, the total heat transfer capacity and the mass of the accumulated frost of the modified MCHX are 9.6–49.7% and 10.3–46.9% higher than the conventional MCHX, respectively. Furthermore, the modified MCHX has greater potential to improve the thermal-hydraulic performance under the condition of more uneven frost layer distribution. The purpose of this work is to provide useful guidance for the optimal design of MCHX under frosting conditions.

AI snapshot

Written from the paper’s full text.

TL;DR

A modified microchannel heat exchanger (MCHX-A) with windward fins extended 4 mm beyond the flat tube was experimentally compared with a conventional MCHX (MCHX-B) under frosting conditions. MCHX-A delayed frost blockage, distributed frost more evenly, and achieved higher heat transfer capacity and frost accumulation over a 60 min frosting cycle.

Key findings

  • During the 60 min frosting cycle, MCHX-A’s total heat transfer capacity and accumulated frost mass were 9.6–49.7% and 10.3–46.9% higher than MCHX-B, respectively.
  • The maximum heat transfer capacity improvement was 49.7% at inlet coolant temperature −10 °C, RH 90%, and air velocity 0.6 m/s; the minimum was 9.6% at −7 °C, RH 80%, and 1.5 m/s.
  • MCHX-B generally had higher air-side pressure drop than MCHX-A, with a maximum difference of 8 Pa greater than MCHX-A under all frosting conditions.
  • Higher RH and lower inlet coolant temperature promoted faster frost growth and earlier heat transfer decline; higher air velocity increased frost mass and pressure drop but improved frost uniformity.

Methods

  • Experimental setup: environmental chamber, air duct, thermostatic water tank, test sample, data acquisition, CCD camera, straighteners, heater for defrosting; T-type thermocouples, hot-wire anemometer, differential pressure sensor, and humidity transmitter.
  • Two MCHX samples: MCHX-A had windward fins extended 4 mm beyond the flat tube; MCHX-B had windward fins flush with the flat tube and leeward fins extended. Flat tubes were vertical, with serpentine louver fins.
  • Test conditions: inlet air temperature fixed at 2 °C; RH 80% and 90%; inlet coolant temperature −7 °C and −10 °C; frontal air velocity 0.6, 1.0, and 1.5 m/s. Each test included 60 min frosting followed by 10 min defrosting. Data reduction covered frost mass, air-side and coolant-side heat transfer, and pressure drop; relative uncertainties were ±0.4–1.3% for pressure drops, ±6.6–9.8% for frost formation rate, and ±5.2–6.9% for heat transfer rate.

Limitations

  • The paper does not state a limitations section.
  • Evident from the text: only two fin configurations and one windward extension length (4 mm) were tested, so the optimal extension length or other geometries were not explored.
  • Evident from the text: results are limited to a single 60 min frosting cycle followed by 10 min defrosting, with no repeated frosting/defrosting cycles or long-term performance assessment; tests were conducted under controlled laboratory conditions with fixed inlet air temperature and limited ranges of RH, coolant temperature, and air velocity.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/app13116378

Cites

33 of 33 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

6 of 19 cited sources checked · 3 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    Louver fins have many edges and corners that can serve as frost nucleation points during frosting.

    “This is because the louver fins have many edges and corners, which can serve as frost nucleation points in the frosting process [11,12].”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [11] Yang, 2021, Condensation frosting and passive anti-frosting, Cell Rep. Phys. Sci. source

      In “Mitigation of frost accumulation” (page not provided), the review says convex tips can be preferred condensation and frosting sites. “Inhibition of ice nucleation” (page not provided) also describes how convex and concave geometries differ in their effect on ice nucleation. The passages do not identify louver fins or establish that their particular edges and corners serve as nucleation points. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [12] Sheng, 2020, Condensate drainage on slit or louvered fins in microchannel heat exchangers for anti-frosting, Energy Build. source
  • Premisecitation

    For the design of a microchannel heat exchanger, to pursue a compact structure, the windward-side fin area is often smaller.

    “However, for the design of the MCHX, to pursue a compact structure, the windward side fin area is often smaller [31].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [31] Qasem, 2018, Compact and microchannel heat exchangers: A comprehensive review of air-side friction factor and heat transfer correlations, Energy Convers. Manag. source

      The Introduction (p. 4) supports the compactness premise, describing microchannel heat exchangers as requiring less space than conventional compact heat exchangers. But neither that passage nor the air-side design discussion (Introduction, p. 5) says that the windward-side fin area is often smaller to achieve compactness. (LLM, conf=0.78)

      Experimental — accuracy not yet measured
  • Findingown data

    The frost blockage of MCHX-A was not as severe as that of MCHX-B.

    “By comparing these pictures, we can see that the frost blockage of the MCHX-A was not as severe as that of the MCHX-B.”
    Quote in the paperSubstantial claim
  • Findingreasoning

    In the early stages of frosting, frost usually forms where the fin and the flat tube are in contact because the temperature is lower there.

    “In the early stages of frosting, frost usually forms where the fin and the flat tube are in contact because the temperature is lower there.”
    Quote in the paperNot a substantial claim
  • Findingown data

    At 30 min, the frost-blocking situation of MCHX-B was much more severe than that of MCHX-A.

    “At 30 min, the frost-blocking situation of the MCHX-B was much more severe than that of the MCHX-A.”
    Quote in the paperSubstantial claim
  • May combine two claims. 37
  • Classified as probably not a substantial claim. 6

  • May combine two claims.

    Premisecitation

    When a microchannel heat exchanger works in winter, frost forms and accumulates faster on the fin surface, leading to decreased airflow rate, increased thermal resistance, and reduced heating capacity of heat pump units.

    “However, when the MCHX works in the winter, the frost will form and accumulate faster on the fin surface [6,7], which will lead to a decrease in airflow rate and an increase in the thermal resistance, thus reducing the heating capacities of the heat pump units [8][9][10].”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [6] Padhmanabhan, 2012, Comparison of Frost and Defrost Performance between Microchannel Coil and Fin-and-Tube Coil for Heat Pump Systems, Int. J. Air-Cond. Refrig. source
    • cites [7] Shao, 2010, Comparison of heat pump performance using fin-and-tube and microchannel heat exchangers under frost conditions, Appl. Energy source
    • cites [8][9][10]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Compared with conventional fin-and-tube heat exchangers, microchannel heat exchangers have higher heat transfer efficiency, less refrigerant charging, and lower cost.

    “Compared with the conventional fin-and-tube heat exchanger (FTHX), the MCHX has the advantages of higher heat transfer efficiency [1,2], less refrigerant charging [3], and lower cost [4,5].”
    Quote in the paperNot a substantial claim2 of 5 sources checked
    • cites [1] Khan, 2011, A review on microchannel heat exchangers and potential applications, Int. J. Energy Res. source
    • cites [2] Dash, 2021, The role of microchannel geometry selection on heat transfer enhancement in heat sinks: A review, Heat Transf. source
    • cites [3] Wang, 2021, Experimental and techno-economic analysis of transcritical CO2 heat pump water heater with fin-and-tube and microchannel heat exchanger, Appl. Therm. Eng. source
    • cites [4] Shen, 2020, Development of high efficiency window air conditioner using propane under limited charge, Appl. Therm. Eng. source
    • cites [5] 2017, Experimental assessment of the replacement of a conventional fin-and-tube condenser by a minichannel heat exchanger in an air/water chiller for residential air conditioning, Energy Build. source

  • Classified as probably not a substantial claim.

    Premisecitation

    Poor drainage performance of a microchannel heat exchanger causes more residual water on the fin surface, resulting in rapid decline of heat exchange performance during re-frosting.

    “In addition, some studies have shown that the poor drainage performance of the MCHX causes more residual water on the fin surface, resulting in the rapid decline of the heat exchange performance during re-frosting [16].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [16] Xia, 2006, Frost, defrost, and refrost and its impact on the air-side thermal-hydraulic performance of louvered-fin, flat-tube heat exchangers, Int. J. Refrig. source

      The Conclusions (p. 12) say that fin corners hinder drainage, leaving droplets that freeze during refrosting and significantly affect heat transfer. But the claim overstates a simple link between more residual water and a rapid performance decline: §3.2.1 (p. 10) reports that the specimen retaining less water showed much greater performance degradation than the one retaining more. (LLM, conf=0.87)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    Over time, the fin tips became colder and frost gradually spread from the base of the fin to the tip; at 15 min, the windward-lengthened fins were covered with frost.

    “Over time, the fin tips became colder, and the frost gradually spread from the base of the fin to the tip; at 15 min, the windward-lengthened fins were covered with frost.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The impact of air velocity on pressure drop was obvious, and the pressure drop increased with an increase in air velocity.

    “The impact of air velocity on pressure drop was also obvious, and the pressure drop increased with the increase in air velocity.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    At lower inlet coolant temperature, the heat transfer rate of the heat exchanger declines earlier, and the decline trend is more obvious.

    “By comparing Figure 5a and Figure 5c, Figure 5b and Figure 5d, it can be concluded that at lower inlet coolant temperature, the heat transfer rate of the heat exchanger declines earlier, and the decline trend is more obvious.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    When the inlet coolant temperature was -10°C, at RH = 90%, the heat transfer rate dropped rapidly after 10 min, while at RH = 80%, the heat transfer rate dropped slowly after 20 min.

    “The comparison between Figure 5a and Figure 5b shows that when the inlet coolant temperature was -10 • C, at RH = 90%, the heat transfer rate dropped rapidly after 10 min, while at RH = 80%, the heat transfer rate dropped slowly after 20 min.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At ua = 1.5 m/s, the mass of frost increased by 74.8-94.2% compared with ua = 0.6 m/s and by 17.9-46.7% compared with ua = 1.5 m/s, respectively, as stated.

    “Similarly, at u a = 1.5 m/s, an increase in mass of frost of 74.8-94.2% and 17.9-46.7%was observed as compared to u a = 0.6 m/s and u a = 1.5 m/s, respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    When the inlet coolant temperature was -7°C, at RH = 90%, the heat transfer rate dropped rapidly after 15 min, while at RH = 80%, the heat transfer rate dropped slowly after 25 min.

    “In addition, the comparison between Figure 5c and Figure 5d shows that when the inlet coolant temperature was -7 • C, at RH = 90%, the heat transfer rate dropped rapidly after 15 min, while at RH = 80%, the heat transfer rate dropped slowly after 25 min.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At ua = 1.5 m/s, pressure drops increased by 60.6-195.4% compared with ua = 0.6 m/s and by 27.3-71.3% compared with ua = 1 m/s.

    “Similarly, at ua = 1.5 m/s, an increase in pressure drops of 60.6-195.4% and 27.3-71.3%was observed as compared to ua = 0.6 m/s and ua = 1 m/s, respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Frost is mainly deposited on the windward side, causing the airflow passage to be blocked by frost quickly.

    “Additionally, in practical applications, some studies have found that frost is mainly deposited on the windward side, causing the airflow passage to be blocked by frost quickly [26].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] Zhang, 2018, An experimental study of frost distribution and growth on finned tube heat exchangers used in air source heat pump units, Appl. Therm. Eng. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The relative uncertainties were ±0.4%-±1.3% for pressure drops, ±6.6%-±9.8% for frost formation rate, and ±5.2%-±6.9% for heat transfer rate.

    “Pressure drops ±0.4%-±1.3%Frost formation rate ±6.6%-±9.8%Heat transfer rate ±5.2%-±6.9%”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    A smaller windward-side fin area causes frost to quickly block the spaces between the louvers on the front side, and the louver fins on the rear side no longer effectively work.

    “This will cause frost to quickly block the spaces between the louvers on the front side, and the louver fins on the rear side will not effectively work anymore.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    During the late stage of frosting, extended fins capture large amounts of frost to a degree that makes the frost distribution more even, thus inhibiting rapid blocking on the front side.

    “During the late stage of frosting, extended fins capture large amounts of frost to a degree that makes the frost distribution more even, thus inhibiting rapid blocking on the front side.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductnone given

    The air-side heat transfer and the coolant-side heat transfer were verified, and their deviation was within ±5%.

    “The air-side heat transfer and the coolant-side heat transfer were verified and their deviation was within ±5%.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    As frosting progresses, thermal resistance develops where the fin and flat tube contact, heat begins to transfer more to the fin away from the flat tube, and therefore the extended portion of the windward-side fins begins to capture frost.

    “As the frosting progresses, thermal resistance develops where the fin and the flat tube are in contact, and heat begins to transfer more to the fin away from the flat tube.Therefore, the extended portion of the windward side fins begins to capture frost.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Frost growth is mainly on the front side, and reducing fin density and increasing louver pitch could effectively improve frosting uniformity.

    “Kim et al. [30] also found that frost growth is mainly on the front side; reducing fin density and increasing louver pitch could effectively improve the frosting uniformity.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Kim, 2014, Thermal performance of microchannel heat exchangers according to the design parameters under the frosting conditions, Int. J. Heat Mass Transf. source

  • May combine two claims.

    Interpretationown data

    For MCHX-B, the frost layer quickly forms on the front side and blocks the airflow passage, resulting in deterioration of the heat transfer rate.

    “However, for the MCHX-B, the frost layer quickly forms on the front side and blocks the airflow passage, resulting in the deterioration of the heat transfer rate.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Poor drainage performance of a microchannel heat exchanger prolongs defrosting time, making its defrosting efficiency 22.5% lower than that of a fin-and-tube heat exchanger.

    “Moreover, the poor drainage performance of the MCHX will prolong the defrosting time, making its defrosting efficiency 22.5% lower than that of the FTHX [17].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [17] Xiong, 2021, Comparison of energy supplies and consumptions in heat pump systems using finned tube and microchannel heat exchangers during defrosting, Int. J. Refrig. source

  • Classified as probably not a substantial claim.

    Premisecitation

    Optimizing the fin shape on the windward side plays a key role in improving the thermal performance of a microchannel heat exchanger.

    “Furthermore, Park et al. [28] claimed that optimizing the fin shape on the windward side plays a key role in improving the thermal performance of the MCHX.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [28] Park, 2015, Local frost behaviors of a scaled-up louvered fin heat exchanger, Int. J. Heat Mass Transf. source

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    For a microchannel heat exchanger, the blocking rate of the windward side was 100% and the leeward side was only 68% when frosting for 200 min.

    “Results reveal that the blocking rate of the windward side was 100%, and the leeward side was only 68% when frosting for 200 min.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [28] Park, 2015, Local frost behaviors of a scaled-up louvered fin heat exchanger, Int. J. Heat Mass Transf. source

  • May combine two claims.

    Interpretationreasoning

    A higher relative humidity carries more moisture, increasing the mass transfer coefficient and promoting frost accumulation.

    “This is because a higher RH will carry more moisture, increasing the mass transfer coefficient and promoting the accumulation of frost.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    When inlet coolant temperature and relative humidity changed to promote frost growth, frost growth on the front side became more active, resulting in a larger decrease in air humidity passing through the rear side, and the driving force of frost growth on the rear side was reduced.

    “Moreover, when the inlet coolant temperature and RH changed to promote frost growth, the growth of the frost on the front side would be more active, resulting in a larger decrease in air humidity passing through the rear side; the driving force of the frost growth on the rear side was reduced.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    An increase in air velocity can make the frost density larger, thus increasing the mass of frost.

    “On the other hand, the increase of u a can make the frost density larger, thus increasing the mass of the frost.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Extending the length of windward fins can effectively capture a large amount of frost and make the frost distribution more uniform, thus inhibiting rapid frost blocking on the front side.

    “Extending the length of windward fins can effectively capture a large amount of frost and make the frost distribution more uniform, thus inhibiting rapid frost blocking on the front side.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The increased frost on MCHX-A was more evenly distributed on the fin, so its frosting performance was better.

    “In general, due to the higher heat transfer capacity of MCHX-A, the accumulation of frost on MCHX-A was bound to be greater, but the increased frost was more evenly distributed on the fin, so its frosting performance was better.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The extended fins delay frost blocking and maintain a better heat transfer rate throughout the frost cycle.

    “As discussed in Section 3.1, the extended fins delay frost blocking and maintain a better heat transfer rate throughout the frost cycle.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The MCHX with extended fins on the windward side can effectively delay the frost-blocking rate and reduce the pressure drop.

    “In summary, it is shown that the MCHX with extended fins on the windward side can effectively delay the frost-blocking rate and reduce the pressure drop.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    With an increase in air velocity, frost uniformity increased, so the extended fins on the windward side promoted frost uniformity potential to be relatively reduced.

    “This is because, with the increase of u a , the frost uniformity increased, so the extended fins on the windward side promoted the frost uniformity potential to be relatively reduced.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    An increase in air velocity can make the frost distribution more uniform, so more frost can attach to the fin surface.

    “As discussed earlier, the increase in air velocity can make the frost distribution more uniform, so more frost can be attached to the fin surface.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    A larger early frost rate causes the airflow passage to be blocked faster and the frost accumulation rate to enter slow growth earlier.

    “However, in the case of a larger early frost rate, the airflow passage will be blocked faster, and the frost accumulation rate will enter into a slow growth earlier.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    At lower inlet coolant temperature, the temperature difference between the fin surface and the air increases, leading to rapid growth of the frost layer, which deteriorates heat transfer of the heat exchanger.

    “This is because the temperature difference between the fin surface and the air increases, leading to the rapid growth of the frost layer, which deteriorates the heat transfer of the heat exchanger.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    With increasing air velocity, frost uniformity increased and the potential of MCHX-A to improve heat transfer performance decreased.

    “With the increase of u a , frost uniformity increased, and the potential of MCHX-A to improve heat transfer performance decreased.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Lower surface temperatures and higher relative humidity promote the growth of windward frosting layers and make frosting less uniform.

    “As discussed above, lower surface temperatures and higher RH promote the growth of windward frosting layers and make frosting less uniform.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    With increasing relative humidity, the moisture content of the inlet air increases, improving the mass transfer potential; with increased mass transfer potential, the frosting rate is accelerated and the heat transfer rate is rapidly reduced.

    “This is because with the increase of RH, the moisture content of the inlet air increases, thus improving the mass transfer potential.With the increase of mass transfer potential, the frosting rate is accelerated, and the heat transfer rate is rapidly reduced.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    When relative humidity increases, the growth of the frost layer is significantly promoted, thus worsening the heat transfer rate.

    “From the above analysis, it can be concluded that when RH increases, the growth of the frost layer is significantly promoted, thus worsening the heat transfer rate.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The extended fins on the windward side capture a large amount of frost, which reduces the airflow attenuation rate and increases the heat transfer rate and frost accumulation rate of the heat exchanger.

    “This is mainly because the extended fins on the windward side capture a large amount of frost, which reduces the airflow attenuation rate and increases the heat transfer rate and frost accumulation rate of the heat exchanger.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    When air velocity decreased, air momentum decreased, the frost growth rate on the rear side slowed while frost growth on the front side had an insignificant influence, resulting in a more uneven distribution of the frost layer.

    “This is because when u a decreased, the air momentum also decreased, and the frost growth rate on the rear side slowed, while the frost growth on the front side had an insignificant influence, resulting in a more uneven distribution of the frost layer [30].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [30] Kim, 2014, Thermal performance of microchannel heat exchangers according to the design parameters under the frosting conditions, Int. J. Heat Mass Transf. source

  • May combine two claims.

    Interpretationown data

    The heat exchanger with extended fins on the windward side can make the frosting more uniform, reduce blocking on the frost side, and show better thermal performance under frosting conditions.

    “In summary, the heat exchanger with extended fins on the windward side can make the frosting more uniform, reduce blocking on the frost side, and show better thermal performance under frosting conditions.”
    Quote in the paperSubstantial claim
39 of 39

  • The paper relies on this without support.

    For microchannel heat exchangers, increasing the fin area on the windward side has not been reported in the literature.

    “For MCHX, this method has not been reported in the literature.”
1 of 1

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Frost mass is reported to increase relative to the same air velocity

    Minor

    The stated 17.9-46.7% increase compares frost mass at 1.5 m/s with frost mass at 1.5 m/s. A quantity cannot increase relative to itself; the comparison velocity appears to be misstated.

1 of 1

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Related

Authors
Xiong, T., Liu, G., & Yan, G.
Affiliations
Xi'an Jiaotong University (CN)
Corresponding author
Liu, Guoqiang
ORCID
Venue
Applied Sciences
Publisher
MDPI AG
Published
2023-05-23
Volume
13
Issue
11
Pages
6378
ISSN
2076-3417 (ISSN-L)
DOI
10.3390/app13116378
OpenAlex
W4378082731
Semantic Scholar
2bee1ce15e61332c90c68adf5827b9666942a2ac
Cited by
6
References
33
Citations by year
2026: 3 · 2025: 2 · 2024: 1
FWCI
0.60
Type
journal article
Language
en
Open access
Licence
Locations
  • Applied Sciences (publishedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Physical Sciences › Engineering › Mechanical Engineering › Heat Transfer and Optimization
  • Physical Sciences › Engineering › Mechanical Engineering › Refrigeration and Air Conditioning Technologies
  • Physical Sciences › Engineering › Mechanical Engineering › Heat Transfer and Boiling Studies
Keywords
microchannel heat exchangers, frost formation, louver fins, thermal-hydraulic performance, heat transfer capacity, refrigeration, heat pumps, fin design optimization

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