Air velocity distribution analysis in the air duct of a display cabinet by PIV technique

Abstract This work is aimed at presenting an analysis, by stereoscopic Particle Image Velocimetry (PIV) technique, of the air speed distribution inside the cooling duct of a display cabinet and its effect on the heat exchange efficiency. Two configurations of the duct, in which the air is forced through the evaporator by one and two fans, respectively, are tested. 3D flow fields, upstream and downstream the evaporator, are determined by PIV performed on three planes containing the mainstream velocity vectors and placed at different heights. Measurements are carried out at the maximum fan rotation rate. The analysis of the air flow distribution at the inlet and outlet of the evaporator shows the capabilities of the PIV technique to highlight insufficiently loaded sections of the evaporator and to estimate the energy transfer efficiency. These results are compared with those of an ideal configuration, in which the air flow rate is uniformly distributed at the evaporator entrance.

[1]  Markus Raffel,et al.  Particle Image Velocimetry: A Practical Guide , 2002 .

[2]  David J. Timoney,et al.  Some effects of air flow maldistribution on performance of a compact evaporator with R134a , 1994 .

[3]  Cláudio Melo,et al.  Measurements of the air flow field in the freezer compartment of a top-mount no-frost refrigerator: the effect of temperature , 2005 .

[4]  Jianying Gong,et al.  Effects of air flow maldistribution on refrigeration system dynamics of air source heat pump chiller under frosting conditions , 2008 .

[5]  Piotr A. Domanski,et al.  Effects of Non-Uniform Refrigerant and Air Flow Distributions on Finned- Tube Evaporator Performance , 2003 .

[6]  Brandon S. Field,et al.  Entrainment of refrigerated air curtains down a wall , 2006 .

[7]  A. Bowman,et al.  Applied smoothing techniques for data analysis : the kernel approach with S-plus illustrations , 1999 .

[8]  David A. Yashar,et al.  Measurement of Air-Velocity Profiles for Finned-Tube Heat Exchangers Using Particle Image Velocimetry , 2008 .

[9]  Denis Flick,et al.  PIV measurement of the flow field in a domestic refrigerator model: Comparison with 3D simulations , 2008 .

[10]  P. Domanski,et al.  Evaporator Optimization for Non-Uniform Air Distribution | NIST , 2010 .

[11]  Brenda S. Henderson,et al.  Jet entrainment rate in air curtain of open refrigerated display cases , 2005 .

[12]  M. Chwalowski,et al.  Verification of evaporator computer models and analysis of performance of an evaporator coil , 1989 .

[13]  J.E.R. Coney,et al.  Airflow maldistribution and the performance of a packaged air conditioning unit evaporator , 2000 .