Nonuniform Flow Distribution Analysis of Air-Cooled Heat Exchanger

Abstract:

The header and the multiple microchannel tubes connected to the header compose a complicated fluid network with several circuits, and the refrigerant flow into the header and is distributed to the microchannels in parallel by the refrigerant pressure driving in the inlet. So all changed details of geometry, operating conditions and thermophysical properties of the fluids lead to nonuniform refrigerant flow distribution in the microchannels. In the present work, one 6-pass 40-tube microchannel condenser as the research objective was equipped in a window type air conditioner prototype with the cooling capacity 5200W for Middle East T3 climate. A mathematical model based on fluid network theory was developed to predict flow distribution and phase separation in 9 flat tubes and their connecting headers on the second pass of the microchannel condenser. In the assumption of homogeneous flow, the mesh current analysis was employed to solve the mass flow of the loop_i+1 by that of the loop_i upon two phase pressure drop. The simulated mass flow rate distribution in 9 tubes is parabolic and approaches to uniform distribution when inlet quality comes to the median 0.45 from both directions.

• Periodical: Applied Mechanics and Materials (Volume 750)
• Pages: 345-351
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.750.345
• Online since: April 2015
• Authors: Hong Liang Lu*, Xiao Long Xue, Xiao Ying Tang, Jian Xun Ding, Xue Feng Geng, Xiao Min Liu
• Keywords: Flow Maldistribution, Microchannel Condenser, Phase Separation, Two-Phase Flow

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