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从理论上分析了膜换湿过程中传质过程和传热过程之间的耦合关系,建立了相应的物理数学模型,发展了一种计算热质耦合的方法。分析结果表明传质过程对传热过程的影响主要体现在两方面:一是质量流携带的焓对传热过程的影响,二是吸附和脱附产生的吸附热对传热过程的影响。而传热过程对传质过程的影响主要体现在温度对膜湿阻的影响。采用数值模拟的方法对热质耦合过程进行了研究,结果表明:当热流与质量流方向相同时,热阻随湿度差的增大显著增大,而当热流与质量流方向相反时,热阻随湿度差的增大显著变小,而膜两侧湿度差对湿阻基本无影响。温度的升高会显著增大传质通量,同时降低湿阻,从而使得热流密度和热阻也受到显著的影响。
The coupling relation between mass transfer process and heat transfer process was analyzed theoretically. A corresponding physical mathematic model was established and a method to calculate thermal mass coupling was developed. The results show that the influence of mass transfer process on the heat transfer process is mainly reflected in two aspects: First, the enthalpy of mass flow entrainment on the heat transfer process; second, the adsorption heat and the desorption heat transfer process. The heat transfer process on the mass transfer process is mainly reflected in the temperature on the wet film resistance. The thermal-mass coupling process is studied by numerical simulation. The results show that when the flow direction is the same, the thermal resistance increases significantly with the increase of humidity difference, while when the flow direction is opposite to the flow direction, the thermal resistance With the increase of humidity difference was significantly smaller, while the humidity difference between the two sides of the membrane wet basically no effect. Increasing the temperature significantly increases the mass transfer flux while decreasing the wet resistance, which in turn causes a significant effect on the heat flux density and the thermal resistance.