PRESSURE DROP CHARACTERISTICS OF R410A-OIL MIXTURE FLOW BOILING IN SMALL SMOOTH TUBES

2010 ◽  
Vol 18 (02) ◽  
pp. 109-116 ◽  
Author(s):  
YIFENG GAO ◽  
BIN DENG ◽  
GUOLIANG DING ◽  
HAITAO HU ◽  
XIANGCHAO HUANG
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Two Phase ◽  
Experimental Conditions ◽  
Mixture Flow ◽  
Frictional Pressure Drop ◽  
New Correlation ◽  
Smooth Tubes ◽  
Local Properties

This study presents experimental frictional pressure drop for R410A/oil mixture flow boiling in small horizontal smooth tubes with inside diameters of 4.18 mm and 2.0 mm. Experimental conditions cover nominal oil concentrations from 0 to 5%. The test results show that the presence of oil enhances two-phase frictional pressure drop about 0–120% and 0–90% at present test conditions for 4.18 mm I.D. smooth tube and 2.0 mm I.D. smooth tube, respectively, and the enhanced effect is more evident at higher vapor qualities where the local oil concentrations are higher. A new correlation to predict the local frictional pressure drop of R410A/oil mixture flow boiling inside conventional size and small smooth tubes is developed based on local properties of refrigerant–oil mixture, and the experimental data of 4.18 mm I.D. and 2.0 mm I.D. smooth tubes and that of 6.34 mm I.D. smooth tube (Hu et al., 2008) are well-correlated with the new correlation.

Two-Phase Frictional Pressure Drop Characteristics of R410A-Oil Mixture Flow Condensation inside 4.18 mm and 1.6 mm I.D. Horizontal Smooth Tubes

2010 ◽  
Vol 16 (4) ◽  
pp. 453-470 ◽  
Author(s):  
Xiangchao Huang ◽  
Guoliang Ding ◽  
Haitao Hu ◽  
Yu Zhu ◽  
Yifeng Gao ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase ◽  
Mixture Flow ◽  
Frictional Pressure Drop ◽  
Smooth Tubes ◽  
Flow Condensation

Experimental Investigation of Flow Boiling Pressure Drop of R134A in a Microscale Horizontal Smooth Tube

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Cristiano Bigonha Tibiriçá ◽  
Jaqueline Diniz da Silva ◽  
Gherhardt Ribatski
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Working Fluid ◽  
Prediction Methods ◽  
Internal Diameter ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop

This paper presents new experimental flow boiling pressure drop results in a microscale tube. The experimental data were obtained under diabatic conditions in a horizontal smooth tube with an internal diameter of 2.32 mm. Experiments were performed with R134a as working fluid, mass velocities ranging from 100 kg/m2 s to 600 kg/m2 s, heat flux ranging from 10 kW/m2 to 55 kW/m2, saturation temperatures of 31°C, and exit vapor qualities from 0.20 to 0.99. Flow pattern characterization was also performed from images obtained by high-speed filming. Pressure drop gradients up to 48 kPa/m were measured. These data were carefully analyzed and compared against 13 two-phase frictional pressure drop prediction methods, including both macro- and microscale methods. Comparisons against these methods based on the data segregated according to flow patterns were also performed. Overall, the method by Cioncolini et al. (2009, “Unified Macro-to-Microscale Method to Predict Two-Phase Frictional Pressure Drops of Annular Flows,” Int. J. Multiphase Flow, 35, pp. 1138–1148) provided quite accurate predictions of the present database.

Measurement and Correlation of Frictional Pressure Drop of R-410A/Oil Mixture Flow Boiling in a 7 mm Straight Smooth Tube

2008 ◽  
Vol 14 (5) ◽  
pp. 763-781 ◽  
Author(s):  
Haitao Hu ◽  
Guoliang Ding ◽  
Wenjian Wei ◽  
Zhence Wang ◽  
Kaijian Wang
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Mixture Flow ◽  
Frictional Pressure Drop

Experimental Investigation of Flow Boiling Pressure Drop of R134a in a Micro-Scale Horizontal Smooth Tube

2010 ◽  
Author(s):  
Cristiano Bigonha Tibiric¸a´ ◽  
Gherhardt Ribatski
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Working Fluid ◽  
Internal Diameter ◽  
Two Phase ◽  
Pressure Drops ◽  
Micro Scale ◽  
Frictional Pressure Drop

This paper presents new experimental flow boiling pressure drop results in a microscale tube. The experimental data were obtained under diabatic conditions in a horizontal smooth tube with internal diameter of 2.3 mm. Experiments were performed with R134a as working fluid, mass velocities ranging from 100 to 600 kg/m2s, heat flux ranging from 10 to 55 kW/m2, saturation temperatures of 31 °C, and exit vapor qualities from 0.20 to 0.99. Flow pattern characterization was also performed from images obtained by high-speed filming. Pressure drops up to 48 kPa/m were measured. These data were carefully analyzed and compared against 13 two-phase frictional pressure drop prediction methods, including both macro- and micro-scale methods. Comparisons against these methods based on the data segregated according to flow patterns were also performed. Overall, the method by Cioncolini et al. [1] provided quite accurate predictions of the present database.

Two-phase pressure drop due to friction in micro-channel

2013 ◽  
Vol 228 (5) ◽  
pp. 921-931 ◽  
Author(s):  
Tae-Woo Lim ◽  
Sam-Sang You ◽  
Jong-Su Kim ◽  
Serng-Bae Moon ◽  
Dong-Hoan Seo
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Homogeneous Model ◽  
Absolute Error ◽  
Heat Fluxes ◽  
Micro Channel ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
New Correlation

This paper deals with an experimental investigation to measure the frictional pressure drops for two-phase flow boiling in a micro-channel with a hydraulic diameter of 500 µm. First, the experimental study is performed under the test conditions: heat fluxes ranging from 100 to 400 kW/m2, vapor qualities from 0 to 0.2, and mass fluxes of 200, 400 and 600 kg/m2s. Then, the frictional pressure drop during flow boiling is estimated using two models: the homogeneous model and the separated flow model. The experimental results show that the two-phase multiplier decreases with the increase of mass flux. In addition, the measured pressure drops are compared with those from a few correlation models available for macro-scales and mini/micro-scales. Finally, the present paper proposes a new correlation for two-phase frictional pressure drops in mini/micro-scales. This correlation model is developed based on the Chisholm constant C as a function of two-phase Reynolds and Weber numbers. It is found that the new correlation satisfactorily predicts the experimental data within mean absolute error (MAE) of 3.9%.

Evaluation Analysis of Prediction Methods for Two-Phase Flow Pressure Drop in Mini-Channels

2008 ◽  
Author(s):  
Licheng Sun ◽  
Kaichiro Mishima
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Turbulent Region ◽  
Frictional Pressure Drop ◽  
New Correlation ◽  
Mini Channels ◽  
Flow Pressure ◽  
Better Than

2092 data of two-phase flow pressure drop were collected from 18 published papers of which the working fluids include R123, R134a, R22, R236ea, R245fa, R404a, R407C, R410a, R507, CO2, water and air. The hydraulic diameter ranges from 0.506 to 12mm; Relo from 10 to 37000, and Rego from 3 to 4×105. 11 correlations and models for calculating the two-phase frictional pressure drop were evaluated based upon these data. The results show that the accuracy of the Lockhart-Martinelli method, Mishima and Hibiki correlation, Zhang and Mishima correlation and Lee and Mudawar correalion in the laminar region is very close to each other, while the Muller-Steinhagen and Heck correlation is the best among the evaluated correlations in the turbulent region. A modified Chisholm correlation was proposed, which is better than all of the evaluated correlations in the turbulent region and its mean relative error is about 29%. For refrigerants only, the new correlation and Muller-Steinhagen and Heck correlation are very close to each other and give better agreement than the other evaluated correlations.

Sign in / Sign up

Export Citation Format

Share Document