在气体通道中，流中的水蒸气冷凝形成热源，而通道中的液态水蒸发（以薄膜或

In the gas channel, the water vapor in the stream condenses to form a heat source, and the liquid water in the channel evaporates (in the form of a thin film or droplets) to form a radiator. When both of the following conditions are met, evaporation occurs: a) Liquid water is present in the gas stream; b) Gas is not saturated (if the pressure drops or the temperature increases, the saturated gas may become unsaturated). Conversely, when the gas is fully saturated or the temperature drops, condensation occurs. Moreover, when the reaction gas or other components "disappear" in the electrochemical reaction, condensation occurs, although this phenomenon does not occur in the channel rather than at the catalyst layer.

In a gas channel, the water vapor in the stream condenses to form a heat source, while the liquid water in the channel evaporates (in the form of a film or droplet) to form a radiator. Evaporation occurs when two conditions are met at the same time: a) liquid water is present in the airflow, and b) the gas is unsaturated (the saturated gas may become unsaturated if the pressure drops or the temperature rises). Conversely, condensation occurs when the gas is fully saturated or the temperature drops. Moreover, condensation occurs when the reaction gas or other components "disappear" in an electrochemical reaction, although this phenomenon does not occur in the channel rather than at the catalyst layer.

In a gas channel, the water vapor in the flow condenses to form a heat source, while the liquid water in the channel evaporates (in the form of a film or a droplet) to form a radiator. Evaporation occurs when both of the following conditions are met: a) there is liquid water in the gas stream; and b) the gas is not saturated (if the pressure drops or the temperature rises, the saturated gas may become unsaturated). On the contrary, condensation occurs when the gas is completely saturated or when the temperature drops. Moreover, when the reaction gas or other components "disappear" in the electrochemical reaction, condensation will occur, although this phenomenon will not occur in the channel rather than in the catalyst layer.<br>