Numerical investigation on thermal non-equilibrium of condensation in the presence of non-condensable gas

作者：Yang, Luopeng^*; Yang, Yan; Li, Hongyou; Gu, Chengyong; Shen, Shengqiang

来源：Desalination and Water Treatment, 2017, 61: 298-305.

DOI：10.5004/dwt.2016.11079

• Thermal non-equilibrium
• Non-condensable gas
• Condensation
• Stagnant film model

Condensation in the presence of non condensable gas (NCG), involving phase change and simultaneous heat and mass transfer progress, is common in many industries applications including nuclear, refrigeration, petrochemical, desalination and power industries. As there exists complex hydrodynamic interaction, heat and mass transfer between the vapor-NCG mixture and condensate for vapor condensation in present of NCG, a simulation model, based on the stagnant film model and gas-liquid two-phase conservation equations coupled with flow regime-dependent correlations, is developed to represent the heat, mass and momentum transfer at the gas-liquid inter-phase. A good agreement between the predictions and the available experimental data validates the accuracy of the two-phase numerical model. The effects of NCG concentration and vapor flow rate on the profiles of local void fractions, temperatures, pressures, heat and mass transfer coefficients are explored. The results show that compared with other parameters, NCG concentration is the key factor affecting the thermal interfacial non-equilibrium and condensation rate due to the fact that a small increase in NCG concentration drastically increase resistances of mass transfer at the gas side and heat transfer at both sides of gas and liquid. The heat transfer is controlled by both phases of condensate and gas through the quantitative analysis on the profiles of heat and mass transfer coefficients and temperatures at the gas-liquid interphase. Increasing the inlet gas mass flow rate contributes to reducing the adverse effect of NCG.

• 出版日期2017-1
• 单位大连理工大学