Horizontal-flow boiling heat transfer using refrigerant mixtures: Final report

Technical Report · Mon May 01 04:00:00 EDT 1989

OSTI ID:6105918

Jung, D S; Didion, D A

Mixture effects were studied on horizontal convective heat transfer for both nonazeotropic, R22/R114, and azeotropic, R12/R152a, mixtures. A test facility was designed, constructed, and operated to simulate evaporators in heat pump and refrigeration systems. More than 3000 local two-phase heat transfer coefficients were obtained under steady state condition for annular flow at a reduced pressure of 0.08. The results indicated that there were two distant heat transfer regions; partial boiling and convective evaporation. In the partial boiling region, heat transfer coefficients were strongly dependent upon heat flux; the heat flux dependence disappeared for high vapor qualities. A full suppression of nucleate boiling was observed for both pure and mixed refrigerants. For a given heat and mass flux, nucleate boiling was suppressed at lower qualities for mixtures than for pure fluids. The unique phenomenon of loss of available superheat for mixtures caused nucleate boiling to be suppressed at lower qualities. An analytical study was performed to predict the transition quality by utilizing a theory of onset of nuclear boiling and phase equilibrium data. The prediction agreed very well with the present data. 77 refs., 62 figs., 14 tabs.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (USA); National Inst. of Standards and Technology (NEL), Gaithersburg, MD (USA). Center for Building Technology
• OSTI ID: 6105918
• Report Number(s): EPRI-ER-6364
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320106 -- Energy Conservation
Consumption
& Utilization-- Building Equipment-- (1987-)
42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BINARY MIXTURES
DISPERSIONS
DOCUMENT TYPES
ENERGY TRANSFER
EVAPORATORS
FLUID FLOW
FLUIDS
HEAT FLUX
HEAT PUMPS
HEAT TRANSFER
MASS TRANSFER
MIXTURES
PROGRESS REPORT
REFRIGERANTS
WORKING FLUIDS