Impact of air flow, temperature distribution, and heat transmission in a refrigerator compartment with and without shelves: A numerical approach

Abstract

This study explores the impact of shelf configurations on airflow, temperature distribution, and heat transfer within a refrigerator’s compartment, aiming to optimize natural convection for enhanced energy efficiency and preservation. This analysis assumes a steady-state and laminar air flow to maintain a constant heat transfer rate, where the flow is to be stable with a consistent two-dimensional pattern. Computational fluid dynamics simulations are conducted with AN-SYS Workbench 2020 R1 to model airflow patterns, temperature gradients, and heat transfer mechanisms under various shelf configurations. The effect of shelves on airflow and temperature distribution inside the refrigerant compartment are investigated and compared the results of temperature and air-flow distribution by altering the number of glass plates. The analysis reveals significant temperature stratification: colder air tends to settle at the bottom, while warmer air accumulates at the top. Glass shelves are found to disrupt the primary airflow along the walls, but they also enhance heat transfer by improving airflow near the walls. This results in higher temperatures in the upper sections of the refrigerator compared to the average, which presents challenges for storing temperature-sensitive items regardless of the shelf configuration. The lowest temperature in the compartment is 272.55 K at 0~10 cm from the bottom wall, and the highest is 279.75 K at 95~100 cm, due to the upward rise of hot air and downward sink of cold air. The pressure ranges are from -7.11 × 10-3 to 2.88 × 10-1 Pa for without shelves and -7.95 × 10-3 to 3.07 × 10-1 Pa with four shelves, respectively. Maximum air velocities are 1.87 × 10-2 m/s for without shelves and 1.61 × 10-2 m/s for with shelves. By measuring temperatures, pressure, and air velocities at various points within the compartment maintained at the optimal temperature, the study highlights the impact of air density changes on airflow and temperature distribution. The findings underscore the importance scope of shelf design and placement in minimizing temperature differentials and improving cooling efficiency. The originality of this work lies in advancing beyond conventional forced convection models by exploring temperature stratification and natural convection effects to optimize shelf layout and improve energy efficiency. This study integrates detailed air flow analysis with practical implications for refrigerator design, advancing beyond conventional forced convection systems. Future research could explore alternative shelf materials, optimal configurations, and consumer behavior to further refine refrigeration Technologies for sustainable household use.

Keywords

• Air Flow
• ANSYS Workbench 2020 R1
• Heat Transmission
• Refrigerator Compartment (with and without shelves)
• Temperature Distribution

References

1. [1] IIF-IIR. Report on refrigeration sector achievements and challenges. World Summit Sustain Dev 2002;33:1–78.
2. [2] Laguerre O, Ben Amara S, Moureh J, Flick D. Numerical simulation of air flow and heat transfer in domestic refrigerators. J Food Engineer 2007;81:144–156. [CrossRef]
3. [3] Laguerre O, Flick D. Heat transfer by natural convection in domestic refrigerators. J Food Engineer 2004;62:79–88. [CrossRef]
4. [4] Billiard F. Refrigerating equipment, energy efficiency and refrigerants. Bull Int Inst Refrig 2005;85:1–7.
5. [5] Laguerre O, Ben Amara S, Flick D. Experimental study of heat transfer by natural convection in a closed cavity: application in a domestic refrigerator. J Food Engineer 2005;70:523–537. [CrossRef]
6. [6] Karayiannis TG, Ciofalo M, Barbaro G. On natural convection in a single and two zone rectangular enclosure. Int J Heat Mass Transf 1992;35:1645–1657. [CrossRef]
7. [7] Betts PL, Bokhari IH. Experiments on turbulent natural convection in an enclosed tall cavity. Int J Heat Fluid Flow 2000;21:675–683. [CrossRef]
8. [8] Bansal PK, Wich T, Browne MW. Optimisation of egg-crate type evaporators in domestic refrigerators. Appl Therm Engineer 2001;21:751–770. [CrossRef]

9. [9] Masjuki HH, Saidur R, Choudhury IA, Mahlia TMI, Ghani AK, Maleque MA. The applicability of ISO household refrigerator–freezer energy test specifications in Malaysia. Energy 2001;26:723–737. [CrossRef]
10. [10] Ding GL, Qiao HT, Lu ZL. Ways to improve thermal uniformity inside a refrigerator. Appl Therm Engineer 2004;24:1827–1840. [CrossRef]
11. [11] Hermes CJL, Melo C, Knabben FT, Gonçalves JM. Prediction of the energy consumption of household refrigerators and freezers via steady-state simulation. Appl Energy 2009;86:1311–1319. [CrossRef]
12. [12] Yang KS, Chang WR, Chen IY, Wang CC. An investigation of a top-mounted domestic refrigerator. Energy Conver Manage 2010;51:1422–1427. [CrossRef]
13. [13] Bayer O, Oskay R, Paksoy A, Aradag S. CFD simulations and reduced order modeling of a refrigerator compartment including radiation effects. Energy Conver Manage 2013;69:68–76. [CrossRef]
14. [14] Yan G, Chen Q, Sun Z. Numerical and experimental study on heat transfer characteristic and thermal load of the freezer gasket in frost-free refrigerators. Int J Refrig 2016;63:25–36. [CrossRef]
15. [15] Avci H, Kumlutaş D, Özer Ö, Özşen M. Optimisation of the design parameters of a domestic refrigerator using CFD and artificial neural networks. Int J Refrig 2016;67:227–238. [CrossRef]
16. [16] Gao F, Shoai Naini S, Wagner J, Miller R. An experimental and numerical study of refrigerator heat leakage at the gasket region. Int J Refrig 2017;73:99–110. [CrossRef]
17. [17] Mansouri R, Bourouis M, Bellagi A. Experimental investigations and modelling of a small capacity diffusion-absorption refrigerator in dynamic mode. Appl Therm Engineer 2017;113:653–662. [CrossRef]
18. [18] Ledesma S, Belman-Flores JM. Mathematical application to analyze the thermal behavior of a domestic refrigerator: influence of the location of the shelves. Int J Refrig 2017;74:362–370. [CrossRef]
19. [19] Söylemez E, Alpman E, Onat A, Yükselentürk Y, Hartomacıoğlu S. Numerical (CFD) and experimental analysis of hybrid household refrigerator including thermoelectric and vapour compression cooling systems. Int J Refrig 2019;99:300–315. [CrossRef]
20. [20] Gulmez M, Yilmaz D. Design and development of a refrigerator door gasket to prevent condensation. Heat Transf Res 2020;51:1061–1072. [CrossRef]
21. [21] Li Z, Ding G, Miao S, Han X. Development of novel air distributor for precise control of cooling capacity delivery in multi-compartment indirect cooling household refrigerators. Int J Refrig 2020;119:175–183. [CrossRef]
22. [22] Wie JH, Cho HW, Park YG, Kim YS, Seo YM, Ha MY. Temperature uniformity analysis of a domestic refrigerator with different multi-duct shapes. Appl Therm Engineer 2021;188:116604. [CrossRef]
23. [23] Logeshwaran S, Chandrasekaran P. CFD analysis of natural convection heat transfer in a static domestic refrigerator. IOP Conf Ser Mater Sci Engineer 2021;1130:012014. [CrossRef]
24. [24] Cui P, He L, Mo X. Flow and heat transfer analysis of a domestic refrigerator with complex wall conditions. Appl Therm Engineer 2022;209:118306. [CrossRef]
25. [25] Jalili B, Jalili P. Numerical analysis of airflow turbulence intensity effect on liquid jet trajectory and breakup in two-phase cross flow. Alexandria Engineer J 2023;68:577–585. [CrossRef]
26. [26] Jalili P, Ganji DD, Nourazar SS. Investigation of convective-conductive heat transfer in geothermal system. Results Phys 2018;10:568–587. [CrossRef]
27. [27] Jalili P, Kazerani K, Jalili B, Ganji DD. Investigation of thermal analysis and pressure drop in non-continuous helical baffle with different helix angles and hybrid nano-particles. Case Stud Therm Engineer 2022;36:102209. [CrossRef]
28. [28] Jalili B, Aghaee N, Jalili P, Domiri Ganji D. Novel usage of the curved rectangular fin on the heat transfer of a double-pipe heat exchanger with a nanofluid. Case Stud Therm Engineer 2022;35:102086. [CrossRef]
29. [29] Salehipour D, Jalili B, Jalili P. Effect of humidification of combustion products in the boiler economizer with spiral geometry. Results Engineer 2024;21:101906. [CrossRef]
30. [30] Sun SL, Liu D, Wang YZ, Kim HB, Hassan M, Hong HJ. Heat transfer performance prediction of Taylor–Couette flow with longitudinal slits using artificial neural networks. Appl Therm Engineer 2023;221:119792. [CrossRef]
31. [31] Mondal D, Alam A, Islam MA. Experimental observation of a small capacity vapor absorption cooling system. Int J Sci Engineer Res 2024;5:456–467.
32. [32] Mondal D, Ikram MO, Rabbi MF, Moral MNA. Experimental investigation and comparison of bend tube parallel & counter flow and cross flow water to air heat exchanger. Int J Sci Engineer Res 2014;5:686–695.
33. [33] Mondal D, Islam MA. Experimental investigation on an intermittent ammonia absorption refrigeration. Mech Engineer Res J 2018;11:59–65.
34. [34] Mondal D, Hori Y, Kariya K, Miyara A, Jahangir Alam M. Measurement of viscosity of a binary mixture of R1123 + R32 refrigerant by tandem capillary tube method. Int J Thermophys 2020;41:1–20. [CrossRef]
35. [35] Mondal D, Kariya K, Tuhin AR, Amakusa N, Miyara A. Viscosity measurement for trans-1,1,1,4,4,4-hexafluoro-2-butene(R1336mzz(E)) in liquid and vapor phases. Int J Refrig 2022;133:267–275. [CrossRef]
36. [36] Mondal D, Kariya K, Tuhin AR, Miyoshi K, Miyara A. Thermal conductivity measurement and correlation at saturation condition of HFO refrigerant trans-1,1,1,4,4,4-hexafluoro-2-butene (R1336mzz(E)). Int J Refrig 2021;129:109–117. [CrossRef]
37. [37] Mondal D, Tuhin AR, Kariya K, Miyara A. Measurement of kinematic viscosity and thermal conductivity of 3,3,4,4,5,5-HFCPE in liquid and vapor phases. Int J Refrig 2022;140:150–165. [CrossRef]
38. [38] Das P, Mondal D, Islam A, Afroj M. Thermodynamic performance evaluation of a solar powered Organic Rankine cycle (ORC) and dual cascading vapor compression cycle (DCVCC): Power generation and cooling effect. Energy Conver Manage 2024;23:100662. [CrossRef]
39. [39] Yilmaz H, Erbay LB, Dogan B. Numerical investigation of the bottom cabinet of a household refrigerator. J Therm Engineer 2016;2:946–953. [CrossRef]
40. [40] Roy PC, Kundu B. Thermodynamic modeling of a pulse tube refrigeration system. J Therm Engineer 2018;4:1668–1679. [CrossRef]
41. [41] Choudhari M, Gawali B, Malwe P, Deshmukh N, Dhalait R. Second order cyclic analysis of counter flow pulse tube refrigerator. J Therm Engineer 2023;9:580–592. [CrossRef]
42. [42] Özkan DB, Ünal F. Energy consumption of defrosting process in no-frost refrigerators. J Therm Engineer 2018;4:2445–2450. [CrossRef]
43. [43] Shikalgar ND, Sapali SN. Energy and exergy analysis of a domestic refrigerator: Approaching a sustainable refrigerator. J Therm Engineer 2019;5:469–481. [CrossRef]
44. [44] Kumar V, Karimi MN, Kamboj SK. Comparative analysis of cascade refrigeration system based on energy and exergy using different refrigerant pairs. J Therm Engineer 2020;6:106–116. [CrossRef]
45. [45] Arslan E, Kosan M, Aktas M, Erten S. Experimental assessment of comparative R290Vs. R449a refrigerants by using 3E (energy, exergy and environment) analysis: A supermarket application. J Therm Engineer 2021;7:595–607. [CrossRef]
46. [46] Gugulothu SK. Enhancement of household refrigerator energy efficiency by studying the effect of refrigerant charge and capillary tube length. J Therm Engineer 2021;7:1121–1129. [CrossRef]
47. [47] Illyas SM, Vellaisamy K, Muthumanokar A. Numerical analysis on heat transfer, flow structure and exergy loss of combined truncated and circular ribs in a square duct. J Therm Engineer 2023;9:1585–1603. [CrossRef]
48. [48] Shariar T, Mondal D, Hasib A, Islam A. Effects of gas-liquid flow and dehumidification performance of a liquid desiccant dehumidifier: A numerical approach for vertical smooth & rough, and inclined rough plates. J Therm Engineer 2024. Doi: 10.14744/thermal.0000883. [Epub Ahead of Print.]
49. [49] Hmood KS, Apostol V, Pop H, Badescu V, Pop E. Drop-in and retrofit refrigerants as replacement possibilities of R134a in domestic/commercial refrigeration and automobile air conditioner applications. J Therm Engineer 2021;7:1815–1835. [CrossRef]
50. [50] Gambhir D, Sherwani AF, Arora A, Ashwni. Parametric optimization of blowdown operated double-effect vapour absorption refrigeration system. J Therm Engineer 2022;8:78–89. [CrossRef]
51. [51] Deshmukh MS, Deshmukh DS, Chavhan SP. A critical assessment of the implementation of phase change materials in the VCC of refrigerator. J Therm Engineer 2022;8:562–572. [CrossRef]
52. [52] Hasheer SKM, Kolla S, Rao DK, Ram YN. Theoretical exploration of low GWP refrigerant mixtures as replacement to HFC-134A in a vapour compression refrigeration system. J Therm Engineer 2023;9:912–920. [CrossRef]
53. [53] Ugudur B, Direk M. Comparative evaluation of experimental ejector refrigeration system for different operating configurations. J Therm Engineer 2023;10:321–329. [CrossRef]
54. [54] Shahini N, Karami M, Behabadi MAA. Numerical investigation of direct absorption evacuated tube solar collector using alumina nanofluid. J Therm Engineer 2024;10:562–571. [CrossRef]
55. [55] Islam L, Mondal D, Islam A, Das P. Effects of heat transfer characteristics of R32 and R1234yf with Al2O3 nanoparticle through U-bend tube evaporator. J Engineer 2024:9991809. [CrossRef]
56. [56] Srivastava A, Maheshwari M. Energy, exergy and economic analysis of ammonia-water power cycle coupled with trans-critical carbon di-oxide cycle. J Therm Engineer 2024;10:599–612. [CrossRef]
57. [57] Srivastava A, Maheshwari M. Thermodynamic analysis of solar assisted binary vapour cycle using ammonia-water mixture and transcritical CO2: A review. J Therm Engineer 2024;10:790–810. [CrossRef]
58. [58] Amin MT. Performance analysis of a new combined absorption-adsorption refrigeration system to improve energy performance. J Therm Engineer 2024;10:722–736. [CrossRef]
59. [59] Inam MI. Direct numerical simulation of laminar natural convection in a square cavity at different inclination angle. J Engineer Adv 2020;01:23–27. [CrossRef]
60. [60] Davis GdV. Laminar natural convection in an enclosed rectangular cavity. Int J Heat Mass Transf 1968;11:1675–1693. [CrossRef]
61. [61] Rincón-Casado A, Sánchez de la Flor FJ, Chacón Vera E, Sánchez Ramos J. New natural convection heat transfer correlations in enclosures for building performance simulation. Engineer Appl Comp Fluid Mech 2017;11:340–356. [CrossRef]