Heating of the right adsorption bed, cooling the left adsorption bed (as shown in Fig. 1a): In this process, the right adsorption bed is heated, and water is desorbed from the right adsorption bed. The desorbed water vapour is then condensed in the right condenser and is stored in the right condensed water tank. Meanwhile, the temperature of the right condensed water tank is higher than that of the evaporating side; Thus, the two-phase thermo-syphon heat transfer cannot be formed by the evaporator and the right condensed water tank. The left adsorption bed is cooled, and water is adsorbed by the left adsorption bed. Much water is evaporated in the left condensed water tank, wherein the temperature declines quickly, and when it is lower than that of the evaporator, the two-phase thermo-syphon heat transfer can be formed by the evaporator and the left condensed water tank. The water evaporates in the evaporator and is condensed in the left heat transfer pipe and then returns back to the evaporator. The cooling capacity can be outputted by the chilled water heat exchanger.