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The combined effects of filling ratio and inclination angle on thermal performance of a closed loop pulsating heat pipe

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Abstract

In the present study, a series of experiments are conducted to investigate the thermal performance of a copper made pulsating heat pipe consisting of uniform flow passages with the cross section of 2 mm × 2 mm. Test conditions cover two orientations (0° and 90°) and six different filling ratios (10%, 25%, 40%, 55%, 70% and 85%). The working fluid used in the experiments is methanol. Heat inputs are applied by 7 W intervals up to an upper safe temperature limit (mean evaporator temperature of nearly 110 °C). In addition to temperature measurements and relevant thermal resistance values, the flow behavior is analyzed via high speed video images. It is concluded that at vertical bottom heating mode (90°), the filling ratio plays a key role in the results, and thus, obvious differences occur in thermal performance depending on the filling ratio. As a general trend, at vertical position, thermal resistance increases with increasing filling ratio for a given heat input value. As an exception, the lowest filling ratio (10%) significantly disobeys this generalization. Thus, the worst thermal performances are obtained for the lowest and topmost filling ratio values (10% and 85%). Nearly for every filling ratio, the system can operate at vertical position, while the system cannot start up and/or properly operate at horizontal position (0°). When the heat pipe is placed horizontally, the effect of filling ratio on the thermal behavior significantly diminishes. As an overall evaluation (including flow patterns and evaporator temperature), the optimum thermal performance is obtained for the filling ratio of 40% in existing conditions.

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Abbreviations

c p :

Specific heat [J kg−1 °C−1].

\( \dot{m} \) :

Cooling water mass flow rate [kg s−1].

Q i :

Heat load supplied to the evaporator region [W].

Q o :

Rejected heat from the condenser region [W].

R th :

Thermal resistance [°C W−1].

T :

Temperature [°C].

ρ :

Density [kg m−3].

e :

(Evaporator)

c :

(Condenser)

in :

Heat sink inlet (related to cooling water).

out :

Heat sink outlet (related to cooling water).

FR :

Filling ratio

FP :

Flat plate

HP :

Heat pipe

PHP :

Pulsating heat pipe

CLPHP :

Closed loop pulsating heat pipe

References

  1. Akachi H (1990) Structure of a heat pipe. US Patent 4,921,041

  2. Karthikeyan VK, Ramachandran K, Pillai BC, Brusly Solomon A (2015) Understanding thermo-fluidic characteristics of a glass tube closed loop pulsating heat pipe: flow patterns and fluid oscillations. Heat Mass Transf 51:1669–1680. https://doi.org/10.1007/s00231-015-1525-3

    Article  Google Scholar 

  3. Czajkowski C, Nowak AI, Błasiak P, Ochman A, Pietrowicz S (2020) Experimental study on a large scale pulsating heat pipe operating at high heat loads, different adiabatic lengths and various filling ratios of acetone, ethanol, and water. Appl Therm Eng 165:114534. https://doi.org/10.1016/j.applthermaleng.2019.114534

    Article  Google Scholar 

  4. Mahajan G, Thompson SM, Cho H (2017) Energy and cost savings potential of oscillating heat pipes for waste heat recovery ventilation. Energy Rep 3:46–53. https://doi.org/10.1016/j.egyr.2016.12.002

    Article  Google Scholar 

  5. Charoensawan P, Khandekar S, Groll M, Terdtoon P (2003) Closed loop pulsating heat pipes part a: parametric experimental investigations. Appl Therm Eng 23:2009–2020. https://doi.org/10.1016/S1359-4311(03)00159-5

    Article  Google Scholar 

  6. Rittidech S, Terdtoon P, Murakami M, Kamonpet P, Jompakdee W (2003) Correlation to predict heat transfer characteristics of a closed-end oscillating heat pipe at normal operating condition. Appl Therm Eng 23:497–510. https://doi.org/10.1016/S1359-4311(02)00215-6

    Article  Google Scholar 

  7. Xu JL, Zhang XM (2005) Start-up and steady thermal oscillation of a pulsating heat pipe. Heat Mass Transf 41:685–694. https://doi.org/10.1007/s00231-004-0535-3

    Article  Google Scholar 

  8. Khandekar S, Gautam AP, Sharma PK (2009) Multiple quasi-steady states in a closed loop pulsating heat pipe. Int J Therm Sci 48:535–546. https://doi.org/10.1016/j.ijthermalsci.2008.04.004

    Article  Google Scholar 

  9. Narasimha KR, Sridhara SN, Rajagopal MS, Seetharamu KN (2012) Influence of heat input, working fluid and evacuation level on the performance of pulsating heat pipe. J Appl Fluid Mech 5:33–42

    Google Scholar 

  10. Chien KH, Lin YT, Chen YR, Yang KS, Wang CC (2010) A novel design of pulsating heat pipe with fewer turns applicable to all orientations. Int J Heat Mass Transf 55:5722–5728. https://doi.org/10.1016/j.ijheatmasstransfer.2012.05.068

    Article  Google Scholar 

  11. Qu J, Wang Q (2013) Experimental study on the thermal performance of vertical closed-loop oscillating heat pipes and correlation modeling. Appl Energ 112:1154–1160. https://doi.org/10.1016/j.apenergy.2013.02.030

    Article  Google Scholar 

  12. Mameli M, Manno V, Filippeschi S, Marengo M (2014) Thermal instability of a closed loop pulsating heat pipe: combined effect of orientation and filling ratio. Exp Thermal Fluid Sci 59:222–229. https://doi.org/10.1016/j.expthermflusci.2014.04.009

    Article  Google Scholar 

  13. Spinato G, Borhani N, Thome JR (2016) Operational regimes in a closed loop pulsating heat pipe. Int J Therm Sci 102:78–88. https://doi.org/10.1016/j.ijthermalsci.2015.11.006

    Article  Google Scholar 

  14. Sedighi E, Amarloo A, Shafii MB (2018) Experimental investigation of the thermal characteristics of single-turn pulsating heat pipes with an extra branch. Int J Therm Sci 134:258–268. https://doi.org/10.1016/j.ijthermalsci.2018.08.024

    Article  Google Scholar 

  15. Sun Q, Qu J, Yuan J, Wang H (2018) Start-up characteristics of MEMS-based micro oscillating heat pipe with and without bubble nucleation. Int J heat mass Transf 122:515–528. https://doi.org/10.1016/j.ijheatmasstransfer.2018.02.003

    Article  Google Scholar 

  16. Srikrishna P, Siddharth N, Reddy SUM, Narasimham GSVL (2019) Experimental investigation of flat plate closed loop pulsating heat pipe. Heat Mass Transf 55:2637–2649. https://doi.org/10.1007/s00231-019-02607-z

    Article  Google Scholar 

  17. Betancur L, Flórez-Mera J, Mantelli M (2020) Experimental study of channel roughness effect in diffusion bonded pulsating heat pipes. Appl Therm Eng 166:114734. https://doi.org/10.1016/j.applthermaleng.2019.114734

    Article  Google Scholar 

  18. Bastakoti D, Zhang H, Li D, Cai W, Li F (2018) An overview on the developing trend of pulsating heat pipe and its performance. Appl Therm Eng 141:305–332. https://doi.org/10.1016/j.applthermaleng.2018.05.121

    Article  Google Scholar 

  19. Liu X, Xu L, Wang C, Han X (2019) Experimental study on thermo-hydrodynamic characteristics in a micro oscillating heat pipe. Exp Therm fluid Sci 109:109871. https://doi.org/10.1016/j.expthermflusci.2019.109871

    Article  Google Scholar 

  20. Yang KS, Cheng YC, Liu MC, Shyu JC (2015) Micro pulsating heat pipes with alternate microchannel widths. Appl Therm Eng 83:131–138. https://doi.org/10.1016/j.applthermaleng.2015.03.020

    Article  Google Scholar 

  21. Kline SJ, McClintock FA (1953) Describing uncertainties in single-sample experiments. Mech Eng 75:3–8

    Google Scholar 

  22. Wan Z, Wang X, Feng C (2020) Heat transfer performances of the capillary loop pulsating heat pipes with spring-loaded check valve. Appl Therm Eng 167:114803. https://doi.org/10.1016/j.applthermaleng.2019.114803

    Article  Google Scholar 

  23. Liu X, Han X, Wang Z, Hao G, Zhang Z, Chen Y (2020) Application of an anti-gravity oscillating heat pipe on enhancement of waste heat recovery. Energy Convers Manag 205:112404. https://doi.org/10.1016/j.enconman.2019.112404

    Article  Google Scholar 

  24. Tseng CY, Yang KS, Chien KH, Jeng MS, Wang CC (2014) Investigation of the performance of pulsating heat pipe subject to uniform/alternating tube diameters. Exp Therm fluid Sci 54:85–92. https://doi.org/10.1016/j.expthermflusci.2014.01.019

    Article  Google Scholar 

  25. Yang H, Khandekar S, Groll M (2009) Performance characteristics of pulsating heat pipes as integral thermal spreaders. Int J Therm Sci 48:815–824. https://doi.org/10.1016/j.ijthermalsci.2008.05.017

    Article  Google Scholar 

  26. Han H, Cui X, Zhu Y, Sun S (2014) A comparative study of the behavior of working fluids and their properties on the performance of pulsating heat pipes (PHP). Int J Therm Sci 82:138–147. https://doi.org/10.1016/j.ijthermalsci.2014.04.003

    Article  Google Scholar 

  27. Fonseca LD, Miller F, Pfotenhauer J (2018) Experimental heat transfer analysis of a cryogenic nitrogen pulsating heat pipe at various liquid fill ratios. Appl Therm Eng 130:343–353. https://doi.org/10.1016/j.applthermaleng.2017.11.029

    Article  Google Scholar 

  28. Khandekar S, Dollinger N, Groll M (2003) Understanding operational regimes of closed loop pulsating heat pipes: an experimental study. Appl Therm Eng 23:707–719. https://doi.org/10.1016/S1359-4311(02)00237-5

    Article  Google Scholar 

Download references

Acknowledgments

This study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK) with the project number of 217 M341.

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Authors and Affiliations

  1. Department of Mechanical Engineering, Recep Tayyip Erdogan University, 53100, Rize, Turkey

    Burak Markal

  2. Department of Energy Systems Engineering, Recep Tayyip Erdogan University, 53100, Rize, Turkey

    Kubra Aksoy

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Correspondence to Burak Markal.

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Markal, B., Aksoy, K. The combined effects of filling ratio and inclination angle on thermal performance of a closed loop pulsating heat pipe. Heat Mass Transfer 57, 751–763 (2021). https://doi.org/10.1007/s00231-020-02988-6

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