Study of Pressure Drop of Refrigerant Mixtures Inside Enhanced Surface Tubing

2001 ◽  
Author(s):  
S. M. Sami ◽  
J. Grell
Keyword(s):  
Pressure Drop ◽  
Reynolds Numbers ◽  
The Other ◽  
Phase Flow ◽  
Specific Pressure ◽  
Two Phase ◽  
Transfer Rates ◽  
Refrigerant Mixtures ◽  
Flow Pressure ◽  
Enhanced Surface

Abstract Two phase flow pressure drop characteristics observed during condensation and boiling of azeotropic refrigerant mixtures R-404A (R125/R134a/R143a:44/4/52), R-407B (R32/R125/ R134a:10/70/20), R407C (R32/R125/R134a:23/25/52) and R408A (R22/R125/R143a:46/7/47) are presented in this paper. Experiments showed that for liquid Reynolds numbers higher than 3.00 E06, R-408A appears to have greater heat transfer rates than the other blends under investigation. Furthermore, it is quite evident from this data that R-407C has the highest specific pressure drop among the refrigerants under investigation.

Study of Liquid Injection on Pressure Drop of Refrigerant Mixtures Inside Enhanced Surface Tubing

2005 ◽  
Author(s):  
S. M. Sami ◽  
J. Comeau
Keyword(s):  
Pressure Drop ◽  
Positive Impact ◽  
Reynolds Numbers ◽  
Two Phase ◽  
Flow Rates ◽  
Refrigerant Mixtures ◽  
Liquid Injection ◽  
Mass Flow Rates ◽  
Flow Pressure ◽  
Enhanced Surface

Two phase flow pressure drop characteristics observed under liquid injection during boiling of refrigerant mixtures R-404A, R407C and R507 as well as R-410A are presented in this paper. Experiments showed that liquid injection tends to decrease the pressure drop during boiling which will have positive impact in increasing the boiling heat transfer rate, heat flux and system efficiency. However, condensation data demonstrated that liquid injection increases the pressure drop. In addition, the data also reveals that the refrigerant under investigation exhibit the same behaviour at higher Reynolds numbers or mass flow rates.

Study of Pressure Drop of Refrigerant Mixtures During Boiling Inside Enhanced Surface Tubing Under Magnetic Field

2005 ◽  
Author(s):  
S. M. Sami ◽  
J. Comeau
Keyword(s):  
Magnetic Field ◽  
Pressure Drop ◽  
Mean Deviation ◽  
Phase Flow ◽  
Two Phase ◽  
Insignificant Effect ◽  
Refrigerant Mixtures ◽  
Flow Pressure ◽  
Enhanced Surface ◽  
The Magnetic Field

Two phase flow pressure drop characteristics observed under magnetic field during boiling of refrigerant mixtures R-404A, and R407C as well as R-507 are presented in this paper. Experiments showed that magnetic field has insignificant effect on the pressure drop. It was evident from the boiling data that the magnetic field has insignificant impact on the pressure drop. Boiling data showed was found to be correlated with a mean deviation between of ±20%.

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.

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