Saturated Flow Boiling Inside Conventional and Mini/Micro Channels: A New General Model for Frictional Pressure Drop Using Genetic Programming

Evaporators with mini and micro channels are one of the main focuses in the design and development of equipment applied to compact refrigeration systems. The objective of this work is to investigate pressure drop of natural refrigerant, isobutane (R-600a), in the single-phase flow through two small tubes, with 1.0 mm and 2.6 mm of internal diameter. Also, the pressure drop was analyzed in the boiling flow in a 2.6 mm internal diameter tube. The experimental tests included mass velocities of 188, 240, 280 and 370 kg/(m²s), heat fluxes in the range from 0 to 134 kW/m² and boiling flow the saturation temperature of 22 ºC and vapor quality up to 0.8. It was possible to observe the significant influence of the diameter and mass velocity on the total pressure drop and the frictional pressure drop, respectively. The experimental frictional pressure drop in flow boiling in 2.6 mm of internal diameter was compared with four different correlations in literature.

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AN EXPERIMENTAL STUDY ON PRESSURE DROP AND HEAT TRANSFER PERFORMANCE OF SUB-COOLED AND SATURATED FLOW BOILING IN A MICRO-TUBE

Equipment ◽

10.1615/ihtc13.p28.290 ◽

2006 ◽

Author(s):

Y. X. Hong ◽

T. D. Wei ◽

W. J. Hui

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Pressure Drop ◽

Heat Transfer Performance ◽

Flow Boiling ◽

Transfer Performance ◽

Saturated Flow

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Measurement and correlation for two-phase frictional pressure drop characteristics of flow boiling in printed circuit heat exchangers

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2021.04.023 ◽

2021 ◽

Author(s):

Haitao Hu ◽

Jianrui Li ◽

Yongdong Chen ◽

Yao Xie

Keyword(s):

Pressure Drop ◽

Heat Exchangers ◽

Flow Boiling ◽

Two Phase ◽

Printed Circuit ◽

Frictional Pressure Drop

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Experimental Studies of Adiabatic Flow Boiling in Fractal-Like Branching Micro-Channels

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C ◽

10.1115/imece2008-69240 ◽

2008 ◽

Cited By ~ 2

Author(s):

Brian J. Daniels ◽

James A. Liburdy ◽

Deborah V. Pence

Keyword(s):

Pressure Drop ◽

Void Fraction ◽

Flow Boiling ◽

Experimental Studies ◽

Channel Length ◽

Channel Height ◽

Channel Network ◽

Adiabatic Flow ◽

Numerical Predictions ◽

Micro Channels

Experimental results of adiabatic boiling of water flowing through a fractal-like branching microchannel network are presented and compared to numerical simulations for identical flow conditions. The fractal-like branching channel network had channel length and width ratios between adjacent branching levels of 0.7071, a total flow length of 18 mm, a channel height of 150 μm and a terminal channel width of 100 μm. The channels were DRIE etched into a silicon disk and pyrex was anodically bonded to the silicon to form the channel top and allowed visualization of the flow within the channels. The water flowed from the center of the disk where the inlet was laser cut through the silicon to the periphery of the disc. The flow rates ranged from 100 to 225 g/min and the inlet subcooling levels varied from 0.5 to 6 °C. Pressure drop across the channel as well as void fraction in each branching level were measured for each of the test conditions. The measured pressure drop ranged from 20 to 90 kPa, and the measured void fraction ranged from 0.3 to 0.9. The pressure drop results agree well with the numerical predictions. The measured void fraction results followed the same trends as the numerical results.

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