Condensation of steam with high CO2 concentration on a vertical plate

Abstract

The effect of a non-condensable gas on steam condensation has been studied. From experimental and theoretical studies to date, clear evidence of significant heat transfer deterioration by the non-condensable gas can be seen. The deterioration varies with the concentration of the non-condensable gas, geometric parameters, system pressure, etc. However, these data and correlations may be unreliable due to the high concentration of CO 2 in the vapor mixture and lack of verification through experiments. In this paper, a systematic investigation has been conducted for film-wise condensation using a vapor mixture of steam and a high concentration of CO 2 . Some data were obtained on a vertical plate, with the average vapor velocity of 1.2 m/s, CO 2 mass fraction of 20%-94% and a pressure of 1 atm. The effects of CO 2 concentration and surface sub-cooling on heat transfer characteristics have been investigated. Moreover, the relevant parameters such as gas/liquid film resistance were included in the description of the condensation phenomenon. The developed correlation for steam and a high concentration of CO 2 , based on experimental results, has a standard deviation of less than ±20%.

Condensation Separation of NO2 with Dimerization Reaction in the Presence of Noncondensable Gas: Critical Assessment and Model Development

“…For h c , the main thermal resistance that deteriorates the condensation heat transfer is in the diffusion layer. 20 The higher NO 2 condensation rate with the increased surface subcooling promotes the accumulation of NCG at the gas–liquid interface, thus increasing the mass transfer resistance according to the diffusion layer theory, 15 and resulting in the decrease of h c . The sharper decreasing trend of HTC versus surface subcooling at a lower NCG mole fraction is associated with more significant inhibition of heat and mass transfer caused by a greater increase in the NCG accumulation.…”

“…Dehbi et al 19 developed a heat and mass transfer analogy (HMTA) model, showing that the increase of NCG from 5 to 10% suppressed heat transfer in water vapor condensation (inlet Nu from 500 to 425). Ge et al 20 experimentally studied the effects of NCG (CO 2 ) at a wide concentration range on water vapor condensation, showing that the increase of the CO 2 mass fraction from 23.3 to 84.0% resulted in the decrease of HTC from 5.5 to 1 kW·m –2 ·K –1 . In terms of the effect of film roughness, a degradation factor defined as the ratio of experimental HTC to theoretical HTC has been commonly employed to correct the error caused by interfacial shear stress while using the conventional models.…”

Condensation of water vapor from humid air inside vertical channels formed by flat plates

“…The condensation heat transfer reduction was confirmed also with the presence of other NCG. Ge et al. (2016) experimentally investigated convection film condensation of steam in the presence of CO 2 on a vertical plate.…”

Theoretical and experimental study of water vapour condensation with high content of non-condensable gas in a vertical tube

“…CO 2 ) is a widely studied topic and its recognition dates back to 1873 [1]. Up to now, the main focus has been on condensation of water vapour with a small fraction of air in tube condensers [2,3]. Such cases can be found in various technological processes such as refrigeration, condensers in power plants, geothermal power plants and various processes in chemical and process indus-try.…”