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对膜换湿过程中吸附热对传热过程的影响进行了理论研究,建立了考虑吸附热的传热过程的数学物理模型.通过分析得到了一个控制吸附热对膜过程中传热影响的无量纲数Ψ=JLλ/δ(T10-T20),并分析了Ψ对换热过程的影响.结果表明:温度梯度与传质方向相同时,有效热流方向会在Ψ=1时发生变化.Ψ<1时,热量将由高温侧向低温侧传递,此时传质通量越大或两侧温差越小,总热阻就越大;而Ψ>1时,热质传递的综合效果是有效热流由低温侧向高温侧传递,此时传质通量越大或两侧温差越小,总热阻就越小.而传热方向与传质方向相反时,吸附热的存在会强化热量由高温侧向低温侧的传递,使得总热阻减小.传质通量J越大或温差越小,总热阻也就越小.
The influence of adsorption heat on the heat transfer process during the membrane wetting process was theoretically studied, and a mathematic model was established to consider the heat transfer process of adsorption heat. (Ψ = JLλ / δ (T10-T20)) and analyzed the effect of Ψ on the heat transfer.The results show that when the temperature gradient is the same as the mass transfer direction, the effective heat flow direction changes when ψ = 1.Ψ < 1, the heat will be transferred from the high temperature side to the low temperature side. At this time, the larger the mass flux or the smaller the temperature difference between the two sides, the greater the total thermal resistance. When Ψ> 1, the combined effect of heat and mass transfer is effective heat flow Low temperature side of the high temperature side of the transfer, then the larger the mass transfer flux or both sides of the temperature difference is smaller, the total thermal resistance is smaller and the heat transfer direction and mass transfer direction opposite, the existence of adsorption heat will strengthen the heat from the high temperature side To the low temperature side of the transfer, making the total thermal resistance decreases mass transfer flux J, the greater the temperature difference or smaller, the total thermal resistance will be smaller.