Non-condensable gases have an important influence on steam condensation by increasing the thermal resistance during condensation and decreasing the heat transfer coefficient. A heat and mass analogy model based on the Nusselt's theory is developed for steam condensation in a vertical pipe with forced convection. The predicted effects of the non-condensable gases on the condensation are with agreement with experimental data. The heat transfer coefficient in the inlet varies from 4.8 kW/(m2·K) to 1.2 kW/(m2·K) for inlet air mass fractions from 8.73% to 22.45%. The heat transfer coefficient then decreases along the pipe. Increasing the inlet temperature from 100 ℃ to 140 ℃ reduces the inlet heat transfer coefficient. The research shows that the inlet temperature and the kind and the mass fraction of non-condensable gas are the important factors governing steam condensation rate.
MA Xizhen
,
JIA Haijun
,
LIU Yang
. Effect of non-condensable gases on steam condensation in a vertical pipe with forced convection[J]. Journal of Tsinghua University(Science and Technology), 2017
, 57(5)
: 530
-536
.
DOI: 10.16511/j.cnki.qhdxxb.2017.22.033
"[1] Othmer D F. The condensation of steam [J]. Industrial & Engineering Chemistry, 1929, 21(6): 576-583. [2] Al-Diwany H K, Rose J W. Free convection film condensation of steam in the presence of non-condensing gases [J]. International Journal of Heat and Mass Transfer, 1973, 16(7): 1359-1369. [3] Rose J W. Condensation of a vapour in the presence of a non-condensing gas [J]. International Journal of Heat and Mass Transfer, 1969, 12(2): 233-237. [4] Minkowycz W J, Sparrow E M. Condensation heat transfer in the presence of noncondensables, interfacial resistance, superheating, variable properties, and diffusion [J]. International Journal of Heat and Mass Transfer, 1966, 9(10): 1125-1144. [5] Huhtiniemi I K, Corradini M L. Condensation in the presence of noncondensable gases [J]. Nuclear Engineering and Design, 1993, 141(3): 429-446. [6] Oh S, Revankar S T. Experimental and theoretical investigation of film condensation with noncondensable gas [J]. International Journal of Heat and Mass Transfer, 2006, 49(15): 2523-2534. [7] Dehbi A A. The Effects of Noncondensable Gases on Steam Condensation under Turbulent Natural Convection Conditions [D]. Cambridge, MA, USA: Massachusetts Institute of Technology, 1991. [8] Lee K Y, Kim M H. Effect of an interfacial shear stress on steam condensation in the presence of a noncondensable gas in a vertical tube [J]. International Journal of Heat and Mass Transfer, 2008, 51(21): 5333-5343. [9] Maheshwari N K, Saha D, Sinha R K. Investigation on condensation in presence of a noncondensable gas for a wide range of Reynolds number [J]. Nuclear Engineering and Design, 2004, 227(2): 219-238. [10] MacAdams W H. Heat Transmission [M]. New York: McGraw-Hill, 1954. [11] Siddique M. The Effects of Noncondensable Gases on Steam Condensation under Forced Convection Conditions [D]. Cambridge, MA, USA: Massachusetts Institute of Technology, 1992. [12] Bird R B. Transport phenomena [J]. Applied Mechanics Reviews, 2002, 55(1): R1-R4. [13] Nithianandan C K, Morgan C D, Shah N H, et al. RELAP5/MOD2 model for surface condensation in the presence of noncondensable gases [C]//Proc 8th Int Heat Transfer Conf. Washington DC, USA: Hemisphere Publishing, 1986, 4: 1627-1633. [14] Kays W M, Moffat R J. The Behavior of Transpired Turbulent Boundary Layers [R]. NASA STI/Recon Technical Report N, 1975, 75, 32383. [15] Uchida H, Oyama A, Togo Y. Evaluation of Post-Incident Cooling Systems of Light Water Power Reactors: No.A/CONF.28/P/436 [R]. Tokyo: Tokyo University, 1964. [16] Akaki H, Kataoka Y, Murase M. Measurement of condensation heat transfer coefficient inside a vertical tube in the presence of noncondensable gas [J]. Journal of Nuclear Science and Technology, 1995, 32(6): 517-526."
