Authors

Refrigerant R410A pressure drop in the coils of air-cooler with internal micro-fins

DOI: 10.17586/1606-4313-2018-17-3-4-13
UDC 621.565

Refrigerant R410A pressure drop in the coils of air-cooler with internal micro-fins

Koshelev S. V., Eideyus A. I., Slastikhin Yu. N.

For citation: Koshelev S.V., Eideyus A.I., Slastikhin Yu.N. Refrigerant R410A pressure drop in the coils of air-cooler with internal micro-fins. Vestnik Mezhdunarodnoi akademii kholoda. 2018. No 3. p. 4-13

Abstract
The article deals with analysis of the efficiency micro-fins tubes in the evaporators. The pressure drop in the coils of duct air cooler which uses R410A refrigerant is also estimated. During heat engineering tests of the refrigeration machine with coil air cooler the pressure drop of R410A refrigerant was measured in four sections of three coils. The measurements were carried out in steady-state regimes alternately along the sections of each coil. For each regime, the basic para-meters of the refrigerant plant were determined. The measured pressure drops were significantly higher than the calculated values obtained from the computer program for smooth-tube coils. The data obtained were compared with the calculations by the available method. The averaged pressure gradients over the sections of the testing air cooler, covering pipes 3,5,7, and 8 of 0.855 m length, were compared with the results of calculations for these methods. The calculated values are again noticeably lower than the pressure gradients averaged over the experimental data. This is partly due to the presence of bends and local resistance at the outlet, where the steam, which forms in the coils, goes into a vertical collector. The discrepancy between the calculated and experimental data shows necessity of an extended research of hydrodynamics and heat transfer of two-phase flows in tubes with micro-fins.

Keywords: refrigerant, evaporation, micro-fin tubes, pressure drop, measurement, calculation.

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