Device and method for recovering by-product oxygen of hydrogen production from electrolyzed water by low-temperature method

A device for recovering by-product oxygen from water-electrolysis hydrogen production using a low-temperature method, wherein the device for recovering by-product oxygen from water-electrolysis hydrogen production comprises an oxygen clarifying system, a pressurizing and heat exchanging system, and a circulating gas compression and expansion refrigeration system;

• the oxygen clarifying system comprises an oxygen self-superheater, an oxygen heater, an oxygen purifier, a water chilling unit, an oxygen clarifier, a valve and a straight pipe section through which various devices are all connected to obtain pure oxygen, wherein the oxygen input end of the oxygen self-superheater is connected to the oxygen output end of a water-electrolysis hydrogen production system, the oxygen output end of the oxygen self-superheater is connected to the oxygen input end of an oxygen heater, the oxygen output end of the oxygen heater is connected to the oxygen input end of the oxygen purifier, the purified oxygen output end of the oxygen purifier is connected to the oxygen input end of the water chilling unit, the oxygen output end of the water chilling unit is connected to the oxygen input end of the oxygen clarifier, and the clarified oxygen at the output end of the oxygen clarifier is sent to the pressurizing and heat exchanging system through a pipeline.