| Author(s): |
Mark A. Kedzierski; D H. Han; |
| Title: |
Influence of Concentration and Additives on R123/Paraffinic Material Oil Boiling Heat Transfer Performance (NISTIR 7336) |
| Published: |
September 01, 2006 |
| Abstract: |
This paper investigates the effect that oil concentration had on the boiling performance of an R123/paraffinic mineral oil mixture on a roughened, horizontal flat surface. For all compositions, the lubricant caused a heat transfer degradation relative to the heat transfer of pure R123 of between 2 % and 70 % for the range of measured heat fluxes. The heat transfer degradation was shown to increase with lubricant mass fraction. The minimum heat transfer degradation for each mixture ranged between 2 % and 12 % and occurred at approximately 20 kW/m2. For a given composition, the heat transfer degradation increased as the heat flux increases from roughly 20 kW/m2 to 90 kW/m2. In addition, the effect of two trial additives on the pool boiling heat transfer of an R123/paraffinic mineral oil mixture were examined in order to test the validity of a theory for choosing oil additives to enhance boiling performance. The verification tests were inconclusive. More research with lubricants and additives with greater differences in surface tensions is required to develop a more rigorous and quantifiable theory for designing additives that improve boiling heat transfer. |
| Citation: |
NIST Interagency/Internal Report (NISTIR) - 7336 |
| Keywords: |
additives;boiling;enhanced heat transfer;paraffinic mineral oil;refrigerant/lubricant mixtures;refrigerants |
| Research Areas: |
Building and Fire Research |
| PDF version: |
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