Numerical Modeling of Two-Phase Flow Distribution Inside Evaporator Headers

2012 ◽  
Author(s):  
Miad Yazdani ◽  
Hailing Wu ◽  
Abbas A. Alahyari ◽  
Thomas D. Radcliff
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Phase Flow ◽  
Predictive Tool ◽  
Two Phase ◽  
Imaging Results ◽  
Discretization Schemes ◽  
Long Time

Two-phase flow distribution inside evaporator headers has been a challenging problem for a long time and having a robust predictive tool could substantially alleviate the costs associated with experimentation with different concepts and configurations. The use of a two-phase CFD model to predict flow distribution inside the header and at the discharge ports is demonstrated in this paper. The numerical domain is comprised of an inlet pipe and a distributor tube representing the header with a series of discharge ports. The flow distribution was initially verified using an air-water experiment, where the two-phase modeling approach, mesh requirements, and discretization schemes were defined. Next, the model was used to predict distribution of R134a in a typical heat exchanger distributor. The flow distribution across the discharge ports was provided to a discretized correlation-based heat exchanger model to predict the temperature and quality distribution along the length of the heat exchanger. The resultant temperature distribution is validated against IR imaging results for various operating conditions and header configurations.

Numerical Modeling of Two-Phase Flow Distribution Inside Evaporator Headers

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Miad Yazdani ◽  
Abbas A. Alahyari ◽  
Hailing Wu ◽  
Thomas D. Radcliff
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Phase Flow ◽  
Predictive Tool ◽  
Two Phase ◽  
Imaging Results ◽  
Discretization Schemes ◽  
Long Time

Two-phase flow distribution inside evaporator headers has been a challenging problem for a long time and having a robust predictive tool could substantially alleviate the costs associated with experimentation with different concepts and configurations. The use of a two-phase CFD model to predict flow distribution inside the header and at the discharge ports is demonstrated in this paper. The numerical domain is comprised of an inlet pipe and a distributor tube representing the header with a series of discharge ports. The flow distribution was initially verified using an air–water experiment, where the two-phase modeling approach, mesh requirements, and discretization schemes were defined. Next, the model was used to predict distribution of R134a in a typical heat exchanger distributor. The flow distribution across the discharge ports was provided to a discretized correlation-based heat exchanger model to predict the temperature and quality distribution along the length of the heat exchanger. The resultant temperature distribution is validated against IR imaging results for various operating conditions and header orientations.

Two-phase flow distribution of R410A within the vertical header of a microchannel heat exchanger

2017 ◽  
Vol 2017.27 (0) ◽  
pp. 427
Author(s):  
Mark Anthony REDO ◽  
Niccolo GIANNETTI ◽  
Jongsoo JEONG ◽  
Koji ENOKI ◽  
Ikuhide OTA ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Microchannel Heat Exchanger

Two-Phase Flow Distribution in a Compact Heat Exchanger Header

2003 ◽  
Author(s):  
Jong-Soo Kim ◽  
Yong-Bin Im ◽  
Jae-Hong Kim ◽  
Ki-Taek Lee
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Flow Distribution ◽  
Compact Heat Exchanger ◽  
Phase Flow ◽  
Two Phase ◽  
Insertion Depth ◽  
Different Types ◽  
Uniform Liquid

In this paper an experimental study was investigated for two-phase distribution in compact heat exchanger header. A test section was consisted of the horizontal header (circular tube: φ 5 mm × 80 mm) and 10 upward circular channels (φ 1.5 mm × 850 mm) using acrylic tube. Three different types of tube insertion depth were tested for the mass flux and inlet quality ranges of 50–200 kg/m2s and 0.1–0.3, respectively. Air and water were used as the test fluids. The distribution of vapor and liquid is obtained by measurement of the total mass flow rate and the calculation of the quality. Two-phase flow pattern was observed, and pressure drop of each channel was measured. By adjusting the insertion depth of each channel a uniform liquid flow distribution through the each channel was able to solve the mal-distribution problem.

Characterization of two-phase flow distribution in microchannel heat exchanger header for air-conditioning system

2019 ◽  
Vol 106 ◽  
pp. 183-193 ◽  
Author(s):  
Mark Anthony Redo ◽  
Jongsoo Jeong ◽  
Niccolo Giannetti ◽  
Koji Enoki ◽  
Seiichi Yamaguchi ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Air Conditioning ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Air Conditioning System ◽  
Microchannel Heat Exchanger

The Influence of Header Design on Two-Phase Flow Distribution in Plate-Fin Heat Exchangers

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Zhe Zhang ◽  
Sunil Mehendale ◽  
Shengnan Lv ◽  
Hui Yuan ◽  
JinJin Tian
Keyword(s):  
Heat Exchanger ◽  
Water Flow ◽  
Heat Exchangers ◽  
Water Distribution ◽  
Single Phase ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase

Abstract Fluid flow maldistribution causes deterioration of heat transfer as well as pressure drop penalty in heat exchangers. A test bench was set up to investigate the effect of different header designs on air-water flow distribution in plate-fin heat exchangers (PFHX). Two-phase flow distribution was examined for air Reynolds numbers (ReG) of 28293542 and inlet qualities (x) of 46.3–64.0%. Two-phase flow distribution was seen to be more uneven in the heat exchanger in comparison with single-phase flow, the water distribution being more uneven than that of the air. For a fixed inlet quality, as the air flowrate was increased, the distribution of two-phase flow became increasingly nonuniform, showing a pattern similar to single-phase flow. Furthermore, the air distribution became more even, while the water flow became more unevenly distributed as the inlet quality increased. To mitigate the maldistribution, perforated plates were incorporated in the heat exchanger header. The improved headers significantly aided in distributing the two-phase flow more evenly. At ReG = 2829 and x = 46.3%, the heat exchanger effectiveness was expressed in terms of the unevenness in quality, Sx. The effectiveness decreased as the unevenness of the flow distribution was exacerbated, emphasizing the significance of uniform phase and flow distribution as a key element of heat exchanger design.

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