Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
권호 표지

Experimental Study on Effects of PAG Oil for $CO_2$ Evaporation Heat Transfer

PAG 오일이 $CO_2$ 증발열전달에 미치는 영향에 관한 실험적 연구

  • Published : 2008.05.10
Download PDF
⟨ Previous Next ⟩

Abstract

In order to investigate $CO_2$ heat transfer coefficient and pressure drop by PAG oil concentration during $CO_2$ evaporation, the experiment on evaporation heat transfer characteristics in a horizontal micro-fin tube was performed. The experimental apparatus consisted of a test section, a DC power supply, a heater, a chiller, a mass flow meter, a pump and a measurement system. Experiment was conducted for various mass fluxes($400{\sim}1200\;kg/m^2s$), heat fluxes($10{\sim}30\;kW/m^2$) and saturation temperatures ($-5{\sim}5^{\circ}C$), and PAG oil concentration($0{\sim}5\;wt%$). The variation of the heat transfer coefficient was different in accordance with the oil concentration. With the increase of the oil concentration, the evaporation heat transfer coefficient decreased and the delay of dryout by oil addition was found. Pressure drop increased with the increase of the oil concentration and heat flux, and the decrease of saturation temperature.

Keywords

References

  1. Lorentzen, G. and Pettersen, J., 1992, A new efficient and environmentally benign system for car air-conditioning, International Journal Refrigeration, Vol. 16, No. 1, pp. 4-12
  2. Cho, K. N. and Tae, S. J., 1999, Effect of refrigeration lubricants on the heat transfer performance in the micro-fin tube evaporator, SAREX, Vol. 11, No. 1, pp. 61-72
  3. Bae, S. C., Kang, T. W., Kim, J. H., Jung, C. Y. and Kim J. S., 1997, Influence of refrigeration oil on evaporation heat transfer of R-134a in a horizontal micro-fin tube, Journal of Air-Conditioning and Refrigeration Vol. 5, No. 1, pp. 45-56
  4. Lim, D. S., Kang, B. H. and Park, K. K., 2005, An experimental study on pressure drop and heat transfer of CO2/oil mixtures in a circular tube, Proceeding of SAREK, pp. 380-385
  5. Seeton, C., Fahl, J. and Henderson, D., 2000, Solubility, viscosity boundary lubrication and miscibility of CO2 and synthetic lubricants, Proceedings of the 4th IIR-Gustav Lorentzen Conference on Natural Working Fluids, Purdue, USA, pp. 417-424
  6. Kim, C. W., 2003, Development of CO2 refrigerant with high efficiency compressor, Report of Samsung Electronics Co. LTD
  7. Choi, J. Y., Kedzierski, M. A. and Domanski, P. A., 1999, A generalized pressure drop correlation for evaporation and condensation of alternative refrigerants in smooth and microfin tubes, NISTIR 6333