Pool Boiling Heat Transfer in Saturated R407C Using Reentrant Cavity Surfaces

Abstract

The nucleate pool boiling phenomenon has immense heat transfer applications due to the ability to remove significant quantities of heat from the heating surface with limited temperature differences. Enhancing the pool boiling heat transfer coefficient (HTC) has gained the important consideration in contemporary research for the conservation and efficient utilization of material and energy in the design of boilers. Many types of modification have been tested for enhancing the HTC. One such method is the application of reentrant cavity. An experiment investigation has been carried out to study the nucleate boiling heat transfer from reentrant cavity tubes to a pool of saturated refrigerant R407C at the saturation temperature of 7 °C and 10 °C. An analysis of experimental data shows the reentrant cavities with the mouth size of 0.21, 0.25, 0.31, 0.41, and 0.51 mm can be advantageous for enhancing the HTC of plain tubes. The mouth size of 0.21 mm for boiling R407C has shown maximum enhancement compared to other sizes. A correlation for reentrant cavity surfaces has also been developed and validated with the experimental results.

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No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Umakant N. Shete

Umakant N. Shete is a Research Scholar in the Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee, India. He received his undergraduate degree from Government College of Engineering, Aurangabad (M.S.) and post graduate degree from Visvesvaraya Technological University, Belgaum, Karnataka. He is currently working in the area of boiling heat transfer of pure and quasi-azeotropic refrigerants.

Ravi Kumar

Ravi Kumar is a Professor in the Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee, India. He has 19 years of teaching experience. His areas of specialization are refrigeration and air-conditioning; two-phase flow and heat transfer; and instrumentation and measurements. Currently he is working in the area of boiling and condensation of refrigerants, and transfer process in capillaries tubes.

Ramesh Chandra

Ramesh Chandra is a Professor at the Institute Instrumentation Centre, Indian Institute of Technology Roorkee, India. He has 27 years of teaching experience. His areas of specialization are superconductivity, nano structural thin film technology dealing with application of supercapacitors, gas sensors, photo-voltaic, wear and corrosion resistant coatings on nano-structural materials.