Heat Transfer Enhancement against Void Fraction in Flow Boiling of R407C using Twisted Tapes
M. D. Hambarde1, Ramakant Shrivastava2
1M. D. Hambarde, Department of Mechanical Engineering, Government College of Engineering, Station Road, Osmanpura, Aurangabad –431005(Maharashtra), India.
2Ramakant Shrivastava, Department of Mechanical Engineering, Government Engineering College, Vidhyanagar, KARAD -415124 (Maharashtra), India.

Manuscript received on 12 April 2019 | Revised Manuscript received on 17 May 2019 | Manuscript published on 30 May 2019 | PP: 1858-1866 | Volume-8 Issue-1, May 2019 | Retrieval Number: A1113058119/19©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Heat transfer enhancement with respect to void fraction (i.e. vapor quality) is investigated in a flow boiling of R407C using twisted tapes in a tubular evaporator of 13.40 mm inner diameter and 2m length. Following operating conditions are considered for investigations: (i) heat flux – 1.5 to 9.5 kWm-2; (ii) mass flux – 150 to 300 kg s-1 m-2; (iii) evaporating temperature ranging from -150C to +150C; (iv) average void fraction( vapor quality) -0.05 to 0.90. Heat Transfer enhancement due to twisted tapes is found to be varied with respect to void fraction (vapor quality) and operating conditions. 10 to 40% void fraction is found to be most suitable range for heat transfer enhancement for all operating conditions. Twisted tapes of twist ratio 12, 10 & 8 are compared for their heat transfer performance. Twisted tape of twist ratio 12 has shown maximum heat transfer enhancement.
Index Terms: Flow Boiling, Heat Transfer Enhancement, refrigerants, R407C, Twisted Tape, Turbulent Promoters.

Scope of the Article:
Heat Transfer