HFC134a(CH2 FCF3) is primarily developed as an alt.ernat.ive t.o t.he ozone depleting refrigerant. CFC12(CC12F2). In t.he case of t.he subst.it.ut.ion of refrigerants for home refrigerators, a t.est., which is aimed at. t.he evaluation of t.he influences on t.he material in t.he refrigerant. in cycle, is necessary as well as thermodynamic charact.erist.ic t.est.. The t.est.ing required includes...

Evaporation of HFC134a inside smooth, horizontal tubes is studied. Te,;ts are made with pure refngerant and with oil-refrigerant mixtures. Heat flux has varied from 2 kW/n? to 10 kW/m . The inner diameter of the tubes are 12 mm. T1.1o evaporators are used, 4 and 10 m long. Oil content is varied from 0 to 2.5 mass percentage (synthetic oil, EXP-0275). Oil free HFC134a is found to have higher hea...

In the present paper the heat exchange performance of a counter flow double-tube condenser for a ternary refrigerant mixture R407C, composed ofHFC32/HFC125/HFC134a, is calculated using a prediction method developed by the present authors. The axial distributions of vapor and liquid bulk mass fraction, temperature, heat flux, mass flux, etc., are obtained for both a smooth tube and a microfin tu...

Experimental measurements of local heat tra nsfer coefficients and pressure drop are made for forced conv ection boiling and condensation for R134a-oil mixtures inside a horizontal tube. The results are compared with the experime ntal data of pure Rl34a. Average convection boiling and cond ensation heat transfer coefficients decreased about 20% at a 10\ o il mass fraction, and boiling and conde...

The conclusions of an experimental program involving altered tensile strength and microstructure of stainless compressor valve steel are described. The paper presents the results of measurements of ductility, corrosion resistance, bending fatigue strength and damping. Encouraging indications have been achieved concerning the possibilities to further improve the characteristics of current materi...