The air humidifier is a device that heats and humidifies air using hot water, with an air flow rate of approximately 50 kg/s. After passing through the humidifier, the temperature and humidity of the air increase, while the temperature of the hot water decreases, thereby transferring low-temperature heat from the hot water to the air. The air humidifier is a unique and critical component of the humidified gas turbine cycle, with its primary functions being to recover low-temperature waste heat from the cycle and increase the working fluid mass flow. The internal thermodynamic process involves complex gas-liquid two-phase flow, accompanied by intense heat and mass transfer between the phases. The performance of the humidifier depends on the coupling of multiple physical fields, such as velocity, temperature, and humidity, and is constrained by geometric boundaries and operating pressure.