Method for operating water electrolysis system capable of stably maintaining quality of hydrogen

Abstract

A method of operating a water electrolysis system including a water electrolysis stack discharging moisture-containing hydrogen gas, a plurality of dehumidification devices including a regenerative adsorbent removing moisture from the moisture-containing hydrogen gas discharged from the water electrolysis stack, temperature and pressure sensors detecting an internal temperature and pressure of each of the plurality of dehumidification devices, and a heating device heating the plurality of dehumidification devices, and in which the plurality of dehumidification devices are connected in parallel to a hydrogen gas supply pipe connecting the water electrolysis stack and the plurality of dehumidification devices and a hydrogen gas discharge pipe discharging moisture-reduced hydrogen gas from the plurality of dehumidification devices and are alternately used to remove moisture from the moisture-containing hydrogen gas, and the hydrogen gas supply pipe and the hydrogen gas discharge pipe are provided with a plurality of inlet valves and outlet valves.