JOURNAL BROWSE
Search
Advanced SearchSearch Tips
Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant
Jo, Geum-Nam; Kim, Byeong-Gi;
  PDF(new window)
 Abstract
The present work experimentally investigated the effects of mass flux, heat flux, inlet quality on the heat transfer performance inside the U-bend of smooth and microfin tube using R-22 and R-407C refrigerants. The parameters were 200 and 400 kg/m s for mass flux, 6 and 12 kw/m for heat flux, 0.1 and 0.2 for inlet quality under the pressure of 0.65 MPa. The apparatus consisted of the test section of four straight sections and three U-bends, preheater, condenser, refrigerant pump, mass flow meter etc. The average heat transfer coefficient at the downstream straight section after U-bend was affected by U-bend due to the centrifugal force and mixing of two-phase flow in the U-bend. The average heat transfer coefficient at the U-bend was 4 ~ 33 % higher than that at the straight section. The average heat transfer coefficients were affected in the order of mass flux, heat flux and inlet quality. The average heat transfer coefficients in the microfin tube were lager by 19 ~ 49% and 33 ~ 69% than that in the smooth tube at the straight section and at the U-bend separately. The average heat transfer coefficients for R-407C were larger by 33 ~ 41% and 17 ~ 29% than that for R-22 in the smooth tube and the microfin tube separately.
 Keywords
Microfin Tube;R-407C;U-Bend;Heat Transfer Coefficient;
 Language
Korean
 Cited by
1.
마이크로핀관 곡관부내 대체 냉매의 응축 열전달에 미치는 냉동기유의 영향,태상진;조금남;

설비공학논문집, 2000. vol.12. 6, pp.541-549
 References
1.
Participants' Handbook:R-22 Alternative Refrigerants Evaluation Program(AREP), 1992.

2.
International Journal of Refrigeration, 1989. vol.12. pp.6-14

3.
Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, 1993. pp.1215-1220

4.
ASHRAE Trans., 1995. vol.95. pp.1055-1061

5.
International Journal of Heat and Mass Transfer, 1996. vol.39. 12, pp.2259-2269

6.
Transactions of the ASME;Journal of Heat Transfer, 1996. vol.118. pp.497-499

7.
대한기계학회논문집, 1996. vol.20. 5, pp.1725-1734

8.
ASHRAE Transactions, 1996. vol.96. pp.830-838

9.
서울대학교 박사학위논문, 1996.

10.
대한기계학회논문집 B, 1996. pp.737-742

11.
ASHRAE Trans., 1995. vol.95. pp.1020-1027

12.
Transactions of the ASME;Journal of Heat Transfer, 1993. vol.115. pp.680-688

13.
ASHRAE Trans., 1993. vol.99. pp.90-96

14.
Int. J. Heat Mass Transfer, 1987. vol.32. 9, pp.979-992

15.
Journal of Heat Transfer, 1990. vol.112. pp.219-228

16.
ASHRAE Trans., 1982. vol.4. 1, pp.24-31

17.
ASHRAE Trans., 1996. pp.90-103

18.
Two-Phase Flow and Heat Transfer. China-US Progress, 0000. pp.273-279

19.
International Journal of Refrigeration, 1994. vol.17. 4, pp.250-256

20.
ASHRAE Handbook : Fundamentals, 1993. pp.17.12-17.13

21.
Dupont, 1995. pp.1-20

22.
Journal of Fluid Engineering, 1985. vol.107. pp.173-182

23.
AIAA 26th Aerospace Sciences Meeting, 1988. pp.1-9

24.
Refrigeration, 1994. vol.69. 795, pp.100-111