There has been no design calculating methods for driving force of natural cycle for evaporators. As a most important influencing factor for the calculating model, the temperature difference (power) is grasped from so many factors whose interrelationship is complex. After the effect of disequilibrium evaporation process in evaporating chamber is analyzed thoroughly, the correction model is proposed which includes the effect coefficient K(1) of evaporating temperature of disequilibrium process and effect coefficient K(2) of evaporating depth ...