Abstract: Each unit cell of a water electrolysis apparatus includes a pair of an anode separator and a cathode separator and a membrane electrode assembly interposed between the pair of separators. The anode separator has a first flow field to which water is supplied, and the cathode separator has a second flow field for producing high-pressure hydrogen through electrolysis of the water. A second seal groove for receiving a second seal member is disposed annularly around the second flow field. A pressure-releasing chamber is disposed outwardly of the second seal groove, is capable of communicating with the second seal groove and communicates with the outside through a depressurizing channel.

Abstract: A water electrolysis apparatus includes an anode separator having a water flow field held in fluid communication with a water supply passage and a discharge passage. The water flow field includes a plurality of water channels, an arcuate inlet buffer, and an arcuate outlet buffer. The water channels have respective ends connected to the arcuate inlet buffer through respective inlet joint channels. The inlet joint channels are oriented at an angle of 90 degrees or greater with respect to respective tangential lines at the ends of the inlet joint channels which are connected to the arcuate inlet buffer.

Abstract: A high-pressure hydrogen producing apparatus includes a cell device and a piston member. The piston member is to apply a pressing force to the cell device from an end of the piston member in a stacking direction in which unit cells are stacked. The piston member is provided with a first hydrogen passage, at least one second hydrogen passage, and a hydrogen lead-out passage. The first hydrogen passage and the second hydrogen passage are spaced at substantially equal angular intervals on a virtual circle centered on a center of an end face of the piston member.

Abstract: A water electrolysis system includes a high-pressure water electrolysis apparatus and a gas-liquid separation device. The gas-liquid separation device includes a block member which includes a gas-liquid separation opening and a water-level detection opening. The gas-liquid separation opening and the water-level detection opening extend substantially vertically and includes respective bottom portions which integrally communicate with a discharge pipe. The discharge pipe is disposed at a lower side portion of the block member. The water-level detection opening includes a top portion and a top water-level detection section. The block member further includes an inlet hole in which the hydrogen is introduced from the high-pressure water electrolysis device. The inlet hole is disposed at an upper side portion of the block member. The inlet hole is positioned above the top water-level detection section of the water-level detection opening.

Abstract: A water electrolysis system includes a high-pressure hydrogen production unit for electrolyzing water to generate oxygen and high-pressure hydrogen (the pressure of the high-pressure hydrogen being higher than that of the oxygen), and a gas-liquid separation unit for removing water contained in the high-pressure hydrogen. The gas-liquid separation unit is placed on a hydrogen pipe for discharging the high-pressure hydrogen from the high-pressure hydrogen production unit. In addition, the water electrolysis system includes a high-pressure hydrogen supply pipe for transferring dewatered high-pressure hydrogen from the gas-liquid separation unit, a cooling unit, which is placed on the high-pressure hydrogen supply pipe and is capable of variably controlling the temperature of the high-pressure hydrogen to adjust the humidity of the high-pressure hydrogen, and a control unit.

Abstract: A hydrogen generating system is equipped with a water electrolysis unit for producing hydrogen by performing electrolysis on pure water supplied from a pure water supply apparatus, with a back-pressure valve mechanism disposed in a hydrogen outlet port of the water electrolysis unit. The back-pressure valve mechanism is equipped with a first back-pressure valve, which sets a first back pressure, for discharging hydrogen to the outside of a hydrogen supply passage, and a second back-pressure valve, which sets a second back pressure at a higher pressure than the first back pressure, for extracting high-pressure hydrogen into the hydrogen supply passage.

Abstract: A water electrolysis system includes a water electrolysis apparatus for producing high-pressure hydrogen by electrolyzing pure water and a casing. The casing defines therein an accommodating chamber accommodating the water electrolysis apparatus etc. therein, first electric component compartments separate from the accommodating chamber and housing a controller and an electrolysis power supply therein, the first electric component compartments having first fans for introducing external air, and a second electric component compartment separate from the accommodating chamber and housing a relay, the second electric component compartment being connected to the first electric component compartments by a pipe.

Abstract: In a unit cell that forms a water electrolysis device, which is an electrochemical device, an electrolyte membrane/electrode structure is sandwiched between an anode-side separator and a cathode-side separator. A load-applying mechanism is disposed between a cathode-side feeder and the cathode-side separator, while an anode-side feeder is set with a smaller contact area range than the aforementioned cathode-side feeder. The anode-side feeder and the cathode-side feeder are set with a larger contact area range than an anode electrode catalyst layer and a cathode electrode catalyst layer, and a contact surface that touches a solid polymer electrolyte membrane on the aforementioned anode-side feeder is disposed projecting farther to the side of the aforementioned solid polymer electrolyte membrane than a contact surface on the anode-side separator and a contact surface on a frame member.

Abstract: A hydrogen electrolysis apparatus includes a stack of unit cells each having a membrane electrode assembly sandwiched between an anode separator and a cathode separator. The anode separator has a first flow field which is supplied with water, and the cathode separator has a second flow field which produces high-pressure hydrogen through an electrolysis of the water. The cathode separator also has a first seal groove defined therein which extends around the second flow field and a first seal member inserted in the first seal groove. The first seal groove and the second flow field are held in fluid communication with each other through passageways. The passageways keep the first seal groove and the second flow field in direct fluid communication with each other in bypassing relation to the boundary between the cathode separator and a solid polymer electrolyte membrane.

Abstract: A water electrolysis system includes a water electrolysis apparatus for electrolyzing pure water supplied from a pure water supply apparatus to produce high-pressure hydrogen. A pressure releasing device is connected between a pipe of the water electrolysis apparatus and a check valve connected to the inlet port of a gas-liquid separator, for releasing the pressure of the high-pressure hydrogen from the water electrolysis apparatus independently from the gas-liquid separator. The pressure releasing device has a bleeder passage including a pressure reducing valve and a solenoid-operated valve.

Abstract: A water electrolysis system includes a water electrolysis apparatus for electrically decomposing water to generate oxygen and high-pressure hydrogen having a pressure higher than the oxygen, a gas-liquid separator connected to a hydrogen pipe which discharges the high-pressure hydrogen from the water electrolysis apparatus, for separating water contained in the high-pressure hydrogen, a high-pressure hydrogen outlet pipe for delivering the high-pressure hydrogen separated from water from the gas-liquid separator, a water drainage line for discharging the water from the gas-liquid separator, and a gas depressurizing line connected to the gas-liquid separator, for degassing the gas-liquid separator before the water is discharged from the water drainage line into the water drainage line.

Abstract: A high-pressure hydrogen producing apparatus includes a cell device and a piston member. The piston member is to apply a pressing force to the cell device from an end of the piston member in a stacking direction in which unit cells are stacked. The piston member is provided with a first hydrogen passage, at least one second hydrogen passage, and a hydrogen lead-out passage. The first hydrogen passage and the second hydrogen passage are spaced at substantially equal angular intervals on a virtual circle centered on a center of an end face of the piston member.

Abstract: A water electrolysis system includes a high-pressure water electrolysis apparatus and a gas-liquid separation device. The gas-liquid separation device includes a block member which includes a gas-liquid separation opening and a water-level detection opening. The gas-liquid separation opening and the water-level detection opening extend substantially vertically and includes respective bottom portions which integrally communicate with a discharge pipe. The discharge pipe is disposed at a lower side portion of the block member. The water-level detection opening includes a top portion and a top water-level detection section. The block member further includes an inlet hole in which the hydrogen is introduced from the high-pressure water electrolysis device. The inlet hole is disposed at an upper side portion of the block member. The inlet hole is positioned above the top water-level detection section of the water-level detection opening.

Abstract: A water electrolysis system includes a water electrolysis apparatus, a low-pressure gas-liquid separator, a high-pressure gas-liquid separator, water pipe, and a decompression water supply device. The high-pressure gas-liquid separator separates the hydrogen received from a cathode of the water electrolysis apparatus and permeation water that has permeated from the anode. The water pipe connects the high-pressure gas-liquid separator and the low-pressure gas-liquid separator and is used for returning the water from the high-pressure gas-liquid separator to the low-pressure gas-liquid separator. The decompression water supply device is arranged at the water pipe and is to decompress the water discharged from the high-pressure gas-liquid separator.

Abstract: A high-pressure water electrolysis apparatus includes a plurality of unit cells each having an anode separator, a cathode separator, and a membrane electrode assembly which is sandwiched between the anode separator and the cathode separator. The membrane electrode assembly includes a solid polymer electrolyte membrane, and an anode current collector and a cathode current collector which are disposed respectively on opposite sides of the solid polymer electrolyte membrane. An electrically-conductive member is interposed between the cathode separator and disc springs and between a plate member and the cathode current collector so as to integrally extend from a region between the cathode separator and the disc springs to a region between the plate member and the cathode current collector. The electrically-conductive member includes an electrically-conductive path which electrically connects the cathode separator with the cathode current collector.

Abstract: A hydrogen filling system to fill a hydrogen fuel tank with hydrogen includes a high-pressure water electrolysis device capable of electrolyzing water to produce oxygen and the hydrogen. A hydrogen pipe connects the high-pressure water electrolysis device and a filling mechanism to fill the hydrogen fuel tank with the hydrogen. At least one hydrogen storage tank is provided to the hydrogen pipe to store the hydrogen produced by the high-pressure water electrolysis device at substantially a same pressure as a maximum filling pressure of the hydrogen fuel tank. A first valve mechanism is arranged downstream of the at least one hydrogen storage tank. A bypass pipe is provided to the hydrogen pipe and connects the high-pressure water electrolysis device and the filling mechanism to bypass the at least one hydrogen storage tank and the first valve mechanism. A second valve mechanism is arranged on the bypass pipe.

Abstract: A water electrolysis system includes a water electrolysis apparatus for producing high-pressure hydrogen by electrolyzing pure water and a casing. The casing defines therein an accommodating chamber accommodating the water electrolysis apparatus etc. therein, first electric component compartments separate from the accommodating chamber and housing a controller and an electrolysis power supply therein, the first electric component compartments having first fans for introducing external air, and a second electric component compartment separate from the accommodating chamber and housing a relay, the second electric component compartment being connected to the first electric component compartments by a pipe.

Abstract: A water electrolysis system includes a water electrolysis apparatus including an electrolyte membrane. The electrolyte membrane is provided between an anode and a cathode. The water electrolysis apparatus is configured to generate oxygen on a side of the anode and hydrogen on a side of the cathode at a pressure higher than a pressure of the oxygen through electrolysis of water. A gas-liquid separation apparatus separates unreacted water and produced gas discharged from a water outlet of the water electrolysis apparatus. A water circulation apparatus circulates the water between the water electrolysis apparatus and the gas-liquid separation apparatus. The water circulation apparatus includes a return pipe having an on-off valve and connecting the water outlet and the gas-liquid separation apparatus. A hydrogen exhaust pipe is connected to the return pipe between the water outlet and the on-off value and extends upward from the water electrolysis apparatus.

Abstract: Each unit cell of a water electrolysis apparatus includes a pair of an anode separator and a cathode separator and a membrane electrode assembly interposed between the pair of separators. The anode separator has a first flow field to which water is supplied, and the cathode separator has a second flow field for producing high-pressure hydrogen through electrolysis of the water. A second seal groove for receiving a second seal member is disposed annularly around the second flow field. A pressure-releasing chamber is disposed outwardly of the second seal groove, is capable of communicating with the second seal groove and communicates with the outside through a depressurizing channel.

Abstract: Each unit cell of a water electrolysis apparatus includes a pair of an anode separator and a cathode separator and a membrane electrode assembly interposed between the pair of separators. The anode separator has a first seal groove extending annularly around an anode current collector, a first seal member being disposed in the first seal groove. The cathode separator has a second seal groove extending annularly around a cathode current collector, a second seal member being disposed in the second seal groove. The first seal groove and the second seal groove are located across the solid polymer electrolyte membrane from each other respectively at different positions with respect to a stacking direction of the separators.