EXPERIMENTAL ANALYSIS OFMULTI TURN CLOSED LOOP PULSATING HEAT PIPE–IMPACTOFFILL RATIO

Authors:

N. Santhi Sree,N. V. V. S.Sudheer,P. Bhramara,

DOI NO:

https://doi.org/10.26782/jmcms.2020.06.00006

Keywords:

Binary mixtures,closed loop pulsating heat pipe,fill ratio,heat input,thermal resistance,working fluids,

Abstract

The heat transfer devices involving phenomena of two phase heat transfer are proven to be the best solution for handling moderate to high heat fluxes in different applications. In this regard, an emerging and new technique is “Pulsating heat pipe cooling”, when it comes to the field of electronics thermal management. CLPHP development meets the current requirements for elimination of moving parts in a cooling system. As the demand for effective and small heat transfer devices is increasing, the present paper describes an experimental analysis of a closed loop pulsating heat pipe. Vertical bottom heat mode is considered as the position of CLPHP for the experimental work. PHP consists of a copper tube of length 262 mm, with capillary dimensions of 2 mm and 3.1 mm having internal and external diameter respectively. The tube is bent in a serpentine manner with 8 number of turns and is connected end to end. Before filling the working fluid in the tube, it is first evacuated partially. Based on the total volume, 50%, 60%, and 75 % filling ratios are considered for analysis. Different pure working fluids, viz., Ethanol, Methanol, Acetone and their mixtures, viz., Ethanol-Methanol, Ethanol-Acetone, and Methanol-Acetone are considered for experimentation. The experiments are conducted for different heat inputs varying from 20 to 100 W. The maximum heat input is dependent on the boiling point of the particular fluid. CLPHP is affected by various parameters like heat input, filling ratio, working fluid etc. Acetone shows least thermal resistance value among pure fluids whereas Ethanol-Acetone shows least thermal resistance and better heat transfer performance among mixtures. For low heat input conditions ethanol shows better performance.

Refference:

I. Akachi, H. Structure of a heat pipe. US Patent No. 5219020. (1993).
II. Barua H, Ali M, Nuruzzaman M, Islam MQ, Feroz CM, 2013. Effect of filling ratio on heat transfer characteristics and performance of a closed loop pulsating heat pipe. Procedia Eng. 56:88–95.doi: 10.1016/j.proeng.2013.03.093
III. Khandekar, S. and Groll, M., 2003.”On the definition of pulsating heat pipes: An overview”,in Proceedings of the Fifth Minsk International Seminar (Heat Pipes, Heat Pumps and Refrigerators), Minsk, Belarus.
IV. Khandek;ar, S.,2004. “Thermo-hydrodynamics of closed loop pulsating heat pipes”, Ph.D., Dissertation, University of Stuttgart, Germany.
V. N. SanthiSree, NVVS Sudheer, P. Bhramara, 2019. “Experimental Analysis of Closed Loop Pulsating Heat Pipe with Different Working Fluids at Different Inclinations(2019),Journal of Jour of Adv Research in Dynamical & Control Systems, Vol. 11, No. 8.
VI. Panigrahi, P, Khandekar, S , 2010.Local hydrodynamics of flow in a pulsating heat pipe: Proceedings Frontiers in Heat Pipes (FHP), DOI: 10.5098/fhp.v1.2.3003
VII. Pramod R. Pachghare. 2016 Experimental analysis of pulsating heat pipe for air Conditioning system, International Journal of Mechanical and Production Engineering, ISSN: 2320-2092, Volume- 4, Issue-6, Jun.
VIII. Sridhara, S., Narasimha, K.R., Rajagopal, M. and Seetharamu,K.,2012 “Influence of heat input, working fluid and evacuation level on the performance of pulsating heat pipe”, Journal of Applied Fluid Mechanics, Vol. 5, No. 2, 33-42.
IX. Vipul M. Patel, H. B. Mehta 2016,“Influence of Gravity onthe Performance of Closed Loop Pulsating Heat Pipe “.Zurich Switzerland Jan 12-13, 18 (1) Part V.
X. X.M. Zhang, J.L. Xu, Z.Q. Zhou, 2004. Experimental study of a pulsating heat pipe using FC-72, ethanol, and water as working fluids, Exp. Heat Transfer 17 47–67.
XI. Yang H, Khandekar S, Groll M, 2008. Operational limit of closed loop pulsating heat pipes. Applied Thermal Eng. 28(1):49–59.doi:10.1016/j.applthermaleng.2007.01.033
XII. Yang, H.; Khandekar, S.; and Groll, M. (2009). Performance characteristics of pulsating heat pipes as integral thermal spreaders. International Journal of Thermal Science, 48 (4), 815–824.
XIII. Zhang, J.L. Xu, Z.Q. Zhou, 2004. Experimental study of a pulsating heat pipe using FC-72, ethanol, and water as working fluids, Exp. Heat Transfer 17 47–67.
XIV. Zhang, Y. and Faghri, A., 2008 “Advances and unsolved issues in pulsating heat pipes”, Heat Transfer Engineering, Vol. 29, No.1, , 20-44

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