An Experimental Investigation of Pressure Drop in Flow Boiling of Pure Refrigerants and Their Mixture in Horizontal Tube

This investigation deals with the pressure drop during forced convection boiling of R-12 under swirl flow inside a horizontal tube. Plain flow and swirl flow pressure drop data are reported for an electrically heated, horizontal, stainless steel, round test-section fitted with twisted tapes having twist ratios from 3.76 to 10.15. A correlation has been presented expressing the swirl flow boiling pressure drop in terms of the twist ratio and the plain flow boiling pressure drop calculated by the Martinelli-Nelson model. The proposed correlation predicts the swirl flow data to within ± 20 percent of the observed values.

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INVESTIGATION ON VOID FRACTION FOR TWO-PHASE FLOW PRESSURE DROP OF EVAPORATIVE R-290 IN HORIZONTAL TUBE

Jurnal Teknologi ◽

10.11113/jt.v78.9590 ◽

2016 ◽

Vol 78 (8-4) ◽

Cited By ~ 1

Author(s):

Agus Sunjarianto Pamitran ◽

Sentot Novianto ◽

Normah Mohd-Ghazali ◽

Nasruddin Nasruddin ◽

Raldi Koestoer

Keyword(s):

Pressure Drop ◽

Void Fraction ◽

Two Phase Flow ◽

Flow Boiling ◽

Homogeneous Model ◽

Saturation Temperature ◽

Horizontal Tube ◽

Phase Flow ◽

Two Phase ◽

Experimental Conditions

Two-phase flow boiling pressure drop experiment was conducted to observe its characteristics and to develop a new correlation of void fraction based on the separated model. Investigation is completed on the natural refrigerant R-290 (propane) in a horizontal circular tube with a 7.6 mm inner diameter under experimental conditions of 3.7 to 9.6 °C saturation temperature, 10 to 25 kW/m2 heat flux, and 185 to 445 kg/m2s mass flux. The present experimental data was used to obtain the calculated void fraction which then was compared to the predicted void fraction with 31 existing correlations. A new void fraction correlation for predicting two-phase flow boiling pressure drop, as a function of Reynolds numbers, was proposed. The measured pressure drop was compared to the predicted pressure drop with some existing pressure drop models that use the newly developed void fraction model. The homogeneous model of void fraction showed the best prediction with 2% deviation

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Experimental investigation and correlation of two-phase frictional pressure drop of R410A–oil mixture flow boiling in a 5mm microfin tube

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2008.08.009 ◽

2009 ◽

Vol 32 (1) ◽

pp. 150-161 ◽

Cited By ~ 24

Author(s):

Guoliang Ding ◽

Haitao Hu ◽

Xiangchao Huang ◽

Bin Deng ◽

Yifeng Gao

Keyword(s):

Experimental Investigation ◽

Pressure Drop ◽

Flow Boiling ◽

Two Phase ◽

Mixture Flow ◽

Frictional Pressure Drop

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Experimental Investigation on Flow Boiling Heat Transfer and Pressure Drop of a Low-GWP Refrigerant R1234ze(E) in a Horizontal Minichannel

Energies ◽

10.3390/en14185972 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5972

Author(s):

Yu Xu ◽

Zihao Yan ◽

Ling Li

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Experimental Investigation ◽

Pressure Drop ◽

Mass Flux ◽

Flow Boiling ◽

Saturation Pressure ◽

Nucleate Boiling ◽

Vapor Quality ◽

Frictional Pressure Drop

To protect the environment, a new low-GWP refrigerant R1234ze(E) was created to substitute R134a. However, its flow boiling performances have not received sufficient attention so far, which hinders its popularization to some extent. In view of this, an experimental investigation was carried out in a 1.88 mm horizontal circular minichannel. The saturation pressures were maintained at 0.6 and 0.7 MPa, accompanied by mass flux within 540–870 kg/m2 s and heat flux within 25–65 kW/m2. For nucleate boiling, a larger heat flux brings about a larger heat transfer coefficient (HTC), while for convective boiling, the mass flux and vapor quality appear to take the lead role. The threshold vapor quality of different heat transfer mechanisms is around 0.4. Additionally, larger saturation pressure results in large HTC. As for the frictional pressure drop (FPD), it is positively influenced by mass flux and vapor quality, while negatively affected by saturation pressure, and the influence of heat flux is negligible. Furthermore, with the measured data, several existing correlations are compared. The results indicate that the correlations of Saitoh et al. (2007) and Müller-Steinhagen and Heck (1986) perform best on flow boiling HTC and FPD with mean absolute deviations of 5.4% and 10.9%.

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