Simulation of Isothermal and Adiabatic Leak Processes of Zeotropic Refrigerant Mixtures.
Simulation of Isothermal and Adiabatic Leak Processes of
Zeotropic Refrigerant Mixtures.
Kim, M. S.; Didion, D. A.
HVAC&R Research, Vol. 1, No. 1, 3-20, January 1995.
refrigerants; predictive models; isothermal leak
process; adiabatic leak process; heat pumps; air
Nonflammable zeotropic mixtures of flammable and
nonflammable rerigerants are possible alternative
refrigerants for use in domestic heat pumps and air
conditioners. Refrigerant leakage from such a system is
of paramount concern since it is possible that a mixture
composition will shift to a flammable range. This paper
presents simulations of leak processes of zeotropic
refrigerant mixtures. Idealized cases of isothermal and
adiabatic leak processes are considered in this study as
representations of slow and fast leaks, respectively.
Results of simulations are presented for a selected
composition of binary and ternary refrigerant mixtures:
R-32/134a and R-32/125/134a. Mass fraction changes of
the mixtures are presented with respect to the
percentage leak of the original charge. In the
isothermal leak process, the fraction of the more
volatile refrigerant in both vapor and liquid phases
decreases for either a vapor or a liquid leak. The mass
fraction changes at a low initial temperature are
greater than those at a high initial temperature.
During the adiabatic leak process, the vapor mass
fraction of the more volatile component increases, while
the liquid mass fraction of that component decreases for
both vapor and liquid leak processes.