Water electrolysis system

Abstract

A water electrolysis system includes a high-pressure water electrolysis apparatus, a water circulation apparatus and a vapor-liquid separation apparatus. The high-pressure water electrolysis apparatus generates oxygen and hydrogen The hydrogen has a pressure higher than a pressure of the oxygen. The water circulation apparatus circulates water to the high-pressure water electrolysis apparatus. The vapor-liquid separation apparatus separates a gas component discharged from an anode side of the high-pressure water electrolysis apparatus from the water in the water circulation apparatus. The vapor-liquid separation apparatus includes a reservoir, a blower and a movable wall. The movable wall is disposed in the reservoir. The movable wall is vertically movable in accordance with a water level in the reservoir and allows the gas component to pass therethrough.

What is claimed is: 
     
         1 . A water electrolysis system comprising:
 a high-pressure water electrolysis apparatus to generate oxygen on an anode side and generate hydrogen on a cathode side by electrolyzing water, the high-pressure water electrolysis apparatus including an electrolyte membrane and power feeders sandwiching the electrolyte membrane therebetween, the hydrogen having a pressure higher than a pressure of the oxygen;   a water circulation apparatus to circulate the water to the high-pressure water electrolysis apparatus; and   a vapor-liquid separation apparatus to separate a gas component discharged from the anode side of the high-pressure water electrolysis apparatus from the water in the water circulation apparatus, the vapor-liquid separation apparatus comprising:
 a reservoir having an inlet port in a lower part thereof through which the gas component from the high-pressure water electrolysis apparatus and the water are introduced; 
 a blower to supply dilution air to the reservoir from an upper part of the reservoir; and 
 a movable wall disposed in the reservoir, the movable wall being vertically movable in accordance with a water level in the reservoir and allowing the gas component to pass therethrough. 
   
     
     
         2 . The water electrolysis system according to  claim 1 ,
 wherein the movable wall includes a porous sheet for setting a gas pressure of the gas component, the gas component being discharged from the high-pressure water electrolysis apparatus and passing through the movable wall from a water surface side to a space side, at a pressure higher than a gas pressure on the space side of the reservoir to which the air is supplied from the blower.   
     
     
         3 . The water electrolysis system according to  claim 1 ,
 wherein the movable wall includes a float that floats on the water and supports the porous sheet.   
     
     
         4 . The water electrolysis system according to  claim 2 ,
 wherein the porous sheet has a porosity to set the gas pressure of the gas component higher than the gas pressure on the space side of the reservoir.