Abstract: Disclosed are a system and method for purifying hydrogen, and a system for producing hydrogen by water electrolysis. The system for purifying hydrogen includes three dryers, and the three dryers share one regeneration cycle module. This significantly reduces a quantity of regeneration cycle modules, and therefore, manufacturing cost of the system is relatively low. In addition, a first gas-gas heat exchanger (4) is arranged in a regeneration cycle system, so that heat exchange can be performed between low-temperature regeneration hydrogen before regeneration and high-temperature regeneration tail gas after regeneration. In this way, residual heat of the high-temperature regeneration tail gas can be fully utilized, and power consumption of a subsequent heater and regeneration cooler can be significantly reduced. Therefore, energy consumption of the system is relatively low.

Abstract: Disclosed are a system and method for purifying hydrogen, and a system for producing hydrogen by water electrolysis. The system for purifying hydrogen includes three dryers, and the three dryers share one regeneration cycle module. This significantly reduces a quantity of regeneration cycle modules, and therefore, manufacturing cost of the system is relatively low. In addition, a first gas-gas heat exchanger (4) is arranged in a regeneration cycle system, so that heat exchange can be performed between low-temperature regeneration hydrogen before regeneration and high-temperature regeneration tail gas after regeneration. In this way, residual heat of the high-temperature regeneration tail gas can be fully utilized, and power consumption of a subsequent heater and regeneration cooler can be significantly reduced. Therefore, energy consumption of the system is relatively low.