Horizontal Flow Boiling of Alternative Refrigerants Within a Fluid Heated Micro-Fin Tube.
Horizontal Flow Boiling of Alternative Refrigerants
Within a Fluid Heated Micro-Fin Tube.
Kaul, M. P.; Kedzierski, M. A.; Didion, D. A.
Process, Enhanced, and Multiphase Heat Transfer. "A
Symposium in Honor of Professor Arthur E. Bergles."
Proceedings. Georgia Institute of Technology. November
16, 1996, Begell House, Inc., New York, NY, Manglik, R.
M.; Kraus, A. D., Editor(s)(s), 167-173 pp, 1996.
refrigerants; enhanced heat transfer; fluid heating;
microfin; refrigerant mixtures
This paper presents local, fluid-heated, flow boiling
measurements for three refrigerant mixtures:  R410B
(R32/125, 45/55 % mass),  R32R134a (28/72 % mass)
and  R407C (R32/125/134a, 25/23/52 % mass). Flow
boiling heat transfer coefficients for the mixtures pure
components and R22 were also measured to establish a
baseline for the heat transfer degradation calculations.
The heat transfer degradation was shown to be a
relatively strong function of heat flux and
thermodynamic mass quality. The heat transfer
degradation associated with the R32/125 mixture was
believed to be mostly due to nonlinear property effects.
The R410B appears to be a good alternative refrigerant
for R22 having approximately a 20% larger heat transfer
coefficient. The degradation of the R407C was shown to
increase with heat flux for all qualities except for
0.6. The dependency of the R32/134a degradation was not
consistent with heat flux. The influence of nonlinear
property effects was apparently responsible for the
inconsistency. Correlations of the two-phase Nusselt
number were derived for each fluid.