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

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.

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00/02839 Two-phase flow characteristics of refrigerant flows in a microchannel heat exchanger

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(00)96752-3 ◽

2000 ◽

Vol 41 (5) ◽

pp. 314

Keyword(s):

Heat Exchanger ◽

Two Phase Flow ◽

Flow Characteristics ◽

Phase Flow ◽

Two Phase ◽

Microchannel Heat Exchanger

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Numerical Modeling of Two-Phase Flow Distribution Inside Evaporator Headers

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2012-72367 ◽

2012 ◽

Cited By ~ 1

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.

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Two-Phase Flow Distribution in a Compact Heat Exchanger Header

1st International Conference on Microchannels and Minichannels ◽

10.1115/icmm2003-1063 ◽

2003 ◽

Cited By ~ 2

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.

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