This report presents the information generated under ASHRAE research project 751-RP. The project objectives as defined in the research proposal by the Principal Investigator and refined by the Project Monitoring Subcommittee are as follows:
1- Experimental determination of pure refrigerant heat transfer coefficients in a bundle of 26 fins/in (1024 fins/meter) integral fin copper tubes with refrigerants R-123, R-134a, and R-22.
2- Experimental determination of the effect of presence of various amounts of mineral oil , up to 10% by weight in the bundle, on the heat transfer coefficient of R-123 flowing in a bundle of 26 FPI tubes.
3- Experimental determination of the effect of presence of various amounts of polyol esther oil (POE), up to 10% by weight in the bundle, on the heat transfer coefficient of R-l 34a in a bundle of 26 FPI tubes.
4- Experimental determination of pure refrigerant heat transfer coefficients in a bundle of Turbo-B2 (LP) copper tubes with refrigerant R-123.
5- Experimental determination of the effect of presence of various amounts of mineral oil , up to 10% by weight in the bundle, on the heat transfer coefficient of R-123 flowing in a bundle of Turbo-B2 (LP) tubes.
6- Experimental determination of pure refrigerant heat transfer coefficients in a bundle of Turbo-B2 (HP) copper tubes with refrigerant R-l34a.
7- Experimental determination of the effect of presence of various amounts of POE oil , up to 10% by weight in the bundle, on the heat transfer coefficient of R-l 34a flowing in a bundle of Turbo-B2 (HP) tubes.
All of the above tests have been completed with an inlet quality of 15% in the heat flux range 2600 Btu/hr-ft2 (8200 W/m2) to 10800 Btu/hr-ft2(34070 W/m2). The heat flux is based on the 3/4 in. (19.05 mm) nominal diameter of the tubes. Mass flowrates of the refrigerant in various tests were set at values which would produce a quality near unity at the top of the bundle. The nominal saturation temperature for all tests is 40 F. The report presents complete heat transfer coefficients for each of the above cases, distribution of the oil in the bundle for each run, as well as the overall effect of the oil in enhancing or reducing the heat transfer coefficient in comparison to the pure refrigerant case. Overall, the presence of oil in concentrations exceeding 1% by weight, causes enhancement of the heat transfer coefficient in 26 FPI integral fin tube bundles while it causes a significant reduction of the coefficient in Turbo-B2 tube bundles. The exact amount of reduction or enhancement depends on the oil concentration and the heat flux as described in this report.
Product Details
- Published:
- 1999
- Number of Pages:
- 66
- File Size:
- 1 file , 1.8 MB
- Product Code(s):
- D-RP-751
