Effects of Non-Uniform Refrigerant and Air Flow Distributions on Finned-Tube Evaporator Performance.
Effects of Non-Uniform Refrigerant and Air Flow
Distributions on Finned-Tube Evaporator Performance.
Choi, J. M.; Payne, W. V.; Domanski, P. A.
Refrigeration International Congress, 21st IIR.
(IRC2003). 10th Technical Session "Energy-Efficient
Heating and Cooling Systems for Buildings. Proceedings.
August 17-22, 2003, Washington, DC, 2004.
refrigerants; refrigeration; degradation; air flow
An experimental investigation was implemented to
determine the capacity degradation due to non-uniform
refrigerant and air flow distributions, and to assess
the potential to recover the lost capacity via
controlling refrigerant distribution between individual
refrigerant circuits. The tests were performed on a
three-circuit, three-depth-row, finned-tube evaporator.
Refrigerant inlet quality, exit saturation temperature,
and exit superheats for the individual circuit were
controlled. The study showed that capacity degradation
due to refrigerant maldistribution can be as much as
30%, even when the overall evaporator superheat is kept
at the target 5.6DGC. Experimental data indicate that
part of this capacity degradation was caused by the
internal heat transfer within the evaporator assembly.
For the coil and air maldistributions studied, he
maximum capacity degradation was found to be 8.7%. A
4.0% capacity recovery was obtained by controlling
refrigerant distribution to obtain the target
5.6DGC at each circuit exit.