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

2016 ◽  
Vol 78 (8-4) ◽  
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

Pressure Drop and Void Fraction in Steam-Water Two-Phase Flow at High Pressure

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Wei Liu ◽  
Hidesada Tamai ◽  
Kazuyuki Takase
Keyword(s):  
High Pressure ◽  
Pressure Drop ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Water Pressure ◽  
Homogeneous Model ◽  
Test Fluid ◽  
Phase Flow ◽  
Two Phase ◽  
Drift Flux Model

For a steam generator (SG) in a commercialized sodium-cooled fast breeder reactor (FBR), flow instability in the water side is one of the most important items needing research. As the first step of this research, thermal-hydraulic experiments using water as the test fluid were performed under high pressure conditions at the Japan Atomic Energy Agency (JAEA) by using a circular tube. Void fraction, pressure drop, and heat transfer coefficient data were obtained under 15, 17, and 18 MPa. This paper discusses the steam-water pressure drop and void fraction. Using the obtained data, we evaluated existing correlations for void fraction and two-phase flow multipliers under high pressure. As a result, the drift flux model implemented in the TRAC-BF1 code was confirmed to suitably predict the void fraction well under the present high pressure conditions. For the two-phase flow multiplier, the Chisholm correlation and the homogeneous model were confirmed to be the best under the present high-pressure conditions.

Pressure Drop Characteristics of R134a Two-Phase Flow in a Horizontal Rectangular Microchannel

2002 ◽  
Author(s):  
X. Tu ◽  
P. Hrnjak
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Homogeneous Model ◽  
Saturation Temperature ◽  
Phase Flow ◽  
Two Phase ◽  
Rectangular Microchannel ◽  
Turbulent Flow Regime ◽  
Parameter Ranges

Adiabatic two-phase flow pressure drop of R134a have been investigated experimentally in a rectangular channel with hydraulic diameter of 0.14 mm. Single-phase flow experiments were also conducted with liquid and vapor R134a, and an empirical correlation was developed for the turbulent flow regime. The parameter ranges examined for two-phase flow are: mass flux from 158 to 785 kg m−2 s−1; vapor quality from 0.01 to 0.95; and saturation temperature at about 24 ~ 32°C. The experimental data were compared with twelve existing correlations. The homogeneous model and the Mishima and Hibiki (1996) correlation give better predictions than any other correlations.

scholarly journals Study Pressure Drop for Two-Phase Flow in a Large Diameter Tube

2019 ◽  
Vol 17 (72) ◽  
pp. 101-109
Author(s):  
Muhsen Koli Nahi
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Homogeneous Model ◽  
Large Diameter ◽  
Horizontal Tube ◽  
Phase Flow ◽  
Water Mixture ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

The aim of this study is to discover the deviation of two phase flow correlations. A comparsion was made between the expermital values of two-phase flow pressure drops data were obtained experimentally by Al-Jumaily (1999) by using air-water mixture in a horizontal tube of (132 mm) nominal diameter and a test section of (32 m) long at pressure and temperature close to atmospheric and those predicted by three correlations well-used in the literature, which show that the homogeneous model was the best

Pressure Drop of Two-Phase Flow Boiling with R-22 and R-290 in 7.6 mm Diameter Tube

2016 ◽  
Vol 818 ◽  
pp. 23-27
Author(s):  
Agus Sunjarianto Pamitran ◽  
Nasruddin ◽  
Helmi Dadang Ardiansyah ◽  
Muhammad Idrus Alhamid
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Phase Flow ◽  
Lower Mass ◽  
Two Phase ◽  
Experimental Pressure

The characteristics of two-phase flow boiling of R-290 are required for replacing R-22 that has been phased-out. The present study focuses on experimental pressure drop for R-22 and R-290. The experiment was run with heat flux of 5.09 kW/m2 to 19.03 kW/m2, mass flux of 114.91 kg/m2s to 751.74 kg/m2s and saturation temperature of 4.77°C to 18.12°C. The present result showed that pressure drop was affected by heat flux, mass flux and saturation temperature. Lower mass flux, heat flux and saturation temperature results in lower pressure drop. The pressure drop of R-290 is lower than that of R-22. Among the existing pressure drop prediction methods, Lokhart-Martinelli (1949) gives the best prediction for the present pressure drop data.

Pressure drop prediction in flow boiling of R-407C in two phase flow using twisted tape insert in horizontal tube

2021 ◽  
Author(s):  
Swati Jadhav ◽  
Manojkumar Hambarde ◽  
Ramakant Shrivastava ◽  
Gopal Nandan
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Horizontal Tube ◽  
Twisted Tape ◽  
Phase Flow ◽  
Two Phase

Pressure Drop Characteristics of Flow Boiling in Narrow Rectangular Channel

2013 ◽  
Author(s):  
Shu-ping Lv ◽  
Liang-ming Pan ◽  
De-qi Chen
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Working Fluid ◽  
Phase Flow ◽  
Two Phase ◽  
Experimental Conditions ◽  
Subcooled Flow Boiling ◽  
Flow Pressure

Pressure drop is the earliest and the most extensive issue in the research of two phase flow. Due to the influence of various factors on two phase flow pressure drop, there is no accurate and general correlation on this issue yet. In this paper, pressure drop characteristics of flow boiling were studied in a single vertical narrow rectangular channel with cross-section of 47 mm by 1.8 mm using water as working fluid. Subcooled flow boiling was experimentally investigated. The experimental conditions included inlet subcooling (2°C∼18°C), mass flow rate (222.3∼457.4 kg.m2s−1) and heat flux (113.6∼270.5 kW/m2). The influence of these parameters on the characteristics of flow boiling pressure drop has been investigated. The experimental results show that the conventional correlations failed to predict the two-phase flow pressure drop in this narrow rectangular channel. According to experiment results, a modified Chisholm correlation was proposed, and the new correlation gave more accurate predictions of the pressure drop.

scholarly journals X-ray Imaging-Based Void Fraction Measurement in Saturated Flow Boiling Experiments with Seawater Coolant

2021 ◽  
Vol 5 (4) ◽  
pp. 31
Author(s):  
Seth Eckels ◽  
Zayed Ahmed ◽  
Molly Ross ◽  
Daniel Franken ◽  
Steven Eckels ◽  
...  
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Void Fraction ◽  
Test Section ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Tap Water ◽  
Phase Flow ◽  
Two Phase ◽  
X Ray

Recent studies have shown that the presence of dissolved salts in water can exhibit peculiar flow boiling and two-phase flow regimes. Two-phase flow and convective flow boiling are typically characterized with the help of void fraction measurements. To quantitatively improve our understanding of two-phase flow and boiling phenomenon with seawater coolant, void fraction data are needed, which can not be obtained from optical imaging. In this paper, we present experimental void fraction measurements of saturated flow boiling of tap water and seawater using X-ray radiography. X-rays with a maximum energy level of 40 KeV were used for imaging the exit region of the heated test section. At lower heat flux levels, the two phase flow in seawater was bubbly and homogeneous in nature, resulting in higher void fractions as compared to tap water. With an increase in heat flux, the flow regime was similar to slug flow, and void fraction measurements approached similarity with tap water. The predicted pressure drop using the measured void faction shows good agreement with the measured total pressure drop across the test section, demonstrating the validity of the measurement process.

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