- Author
-
Kim, M. S.
|
Didion, D. A.
- Title
- Simulation of Leak/Recharge Process of Refrigerant Mixtures.
- Coporate
- Seoul National Univ., Korea
National Institute of Standards and Technology, Gaithersburg, MD
- Journal
-
HVAC&R Research,
Vol. 1,
No. 3,
242-254,
July 1995
- Keywords
-
refrigerants
|
leak process
|
mass fraction
|
recharge
|
refrigerant mixtures
|
zeotrope
|
flammable refrigerant
- Abstract
- As alternatives to ozone-depleting refrigerants, zeotropic and near-azeotropic mixtures of nonflammable and flammable hydrofluorocarbon (HFC) refrigerants are being evaluated for use in most refrigeration/air conditioning machines that do not have flooded evaporators. Refrigerant leakage from these systems is very important because a mixture composition may shift to a flammable range. After a recharging process, the mixture composition changes, as does the performance of the system. A model simulating isothermal and adiabatic leaks was presented by the authors in the first issue of this journal. This paper presents an isothermal or adiabatic leak simulation with a recharge process which is capable of simulating up to five cycles. Case studies of an isothermal leak of vapor and liquid phases, with a liquid or vapor recharge process were conducted for binary and ternary refrigerant mixtures at the specified overall composition of R-32/134a (30/70% by mass) and R-32/125/134a (23/25/52% by mass). Mass fraction changes in both vapor and liquid phases are presented. A theoretical machinery system performance change after each recharge was evaluated using another NIST simulation model. Changes in capacity and COP are presented.