n Without oil filling Data position of the Arti B3-SV-14-D Bevel-helical speed reducers B3

Flender/Flender Gear Units/Bevel-helical speed reducers B3

ogramme, the test system is to be further developed as regards its measurement range and accuracy In particular, the sensors must be adapted to the respective requirements The envisaged measurements include the technically relevant gas and liquid states and encompass temperatures of -2 " 2 8 2 9 " and pres- sures of 0 1 5 < 5 bar 3. Results ~~ ~~ ~___ The heat transfer during nucleate boiling on wire ( = 0 1 mm) was investigated using mix- tures ofthealternativerefrigerant R1a andthreedifferent refrigeratoroils (poly0 esters)The heat transfer coefficient was measured as function of the heat flux density at temperatures between- 6"Cand 3 "Cand oil massfractions betweenO%and 1% Aconsiderabledropin the heat transfer coefficient to rox 6 to 7% of that of pure R1a already occurred with very low oil mass fractions (0 5/orpor all three R1a/oil mixtures Comparative measurements on tube ( = 2 mm) resulted in only slight influence of the oil on heat transfer with low oil mass fractions (< 2%), the heat transfer was reduced to approx. 8 to 9% of that of pure R1a.Similar results wereobtained withthetubeand thewireatoil massfractionsabove2Yo The influence of the oil on the heat transfer always increased with increasing temperature and measured and correlated over broad pressure and temperature range using the transient hot-wire method ~ ~ ~ ~ ~~ ~~ ___~____~___ heat flux density. In addition, the thermal conductivity of R1a, R1a, R3 and R1 was ~ ~ ~ 2 Duration: 0.0.8 - 3.0.9 0ZH8K1 Subject: Collaborative project: Reduction of CFC emissions in air-conditioning/ refrigeration. Sub-project: Ozone-safe refrigerants: Determining the thermodynamic properties of the R1a/R1a mixture Research centre: lnstitut fur Thermodynamik der Universitat Hannover Callinstrasse 3, 3 6 Hannover Government sponsorship: DM 1,9.0 Sponsorship ratio: 5 Yo 1. Purpose of the project Two ozone-safe substances, 1,-difluoroethane (RI 5a) and 1,1,1,2-tetrafluoroethane (RI