Honda Motor Co., Ltd.

Eastman-kodak Company

Jun Takeuchi

Koji Nakazawa

Daisuke Kurashina

Hisashi Nagaoka

Masanori Okabe

Kenji Taruya

Yuji Yamakawa

Tetsuya Yoshida

Aoi Miyake

Hiroyuki Ishikawa

Jeffrey W Schrieber

Thomas V Doherty

Shuichi Kazuno

Koichi Takahashi

Takeo Fukuda

Akihiro Noda

Yukihiro Fukushima

Yuji Asano

Christopher James Chuah

Nobuyoshi Yoshida

Kazuya Aoki

Akifumi Otaka

Hitoshi Tsuru

Yukihiro Yamakoshi

A water electrolysis system includes: a water electrolyzer configured to electrolyze water to generate gas including oxygen and hydrogen; a gas-liquid separator configured to separate gas phase including hydrogen from liquid phase of the gas generated by the water electrolyzer; a water level detector configured to detect a water level in the gas-liquid separator; a pressure detector configured to detect a pressure of the gas phase in the gas-liquid separator; and a CPU and a memory coupled to the CPU. The CPU is configured to perform: calculating an error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase in the gas-liquid separator detected by the pressure detector.

Water electrolysis system and water level error calculation apparatus

A hydrogen station includes a state management apparatus that is connected to each of a plurality of systems and manages the states of the plurality of systems, and a safety control apparatus that is formed separately from the main equipment and is connected to the state management apparatus. The state management apparatus performs first watchdog control to check operations of the plurality of systems and the safety control apparatus performs second watchdog control to check an operation of the state management apparatus. The state management apparatus or the safety control apparatus cuts off the power supply from the safety control apparatus to the main equipment if an abnormality is recognized by the second watchdog control, even if the first watchdog control indicates correct operation.

Hydrogen station

A water electrolysis system is equipped with a water electrolysis device, a water supply passage, a hydrogen supply passage, a gas-liquid separator, a first water drainage passage, a first water drainage valve, a second water drainage valve, a determination unit, and a valve control unit. In a method of stopping operation of the water electrolysis system, in a water drainage step, in the case that the determination unit determines that operation of the water electrolysis device has been stopped, the first water drainage valve is controlled to be placed in a valve open state, thereby draining liquid water from the gas-liquid separator into the first water drainage passage.

Water electrolysis system and method of stopping operation thereof

In a water electrolysis system and a method of controlling the water electrolysis system, a control device places a high pressure water discharge solenoid valve, a depressurizing solenoid valve, and a low pressure water discharge solenoid valve in the closed state. Further, a pressure acquisition unit obtains the electrolysis time pressure as a pressure in the low pressure water sealing container during production of hydrogen by a water electrolyzer. Further, the control device determines the occurrence of hydrogen leakage in a depressurizing line based on at least the electrolysis time pressure.

Water electrolysis system and method of controlling the same

A water electrolysis system includes a water electrolysis apparatus, an electric component, and a casing. The electric component is to operate the water electrolysis apparatus. The casing includes a housing chamber, an electric component chamber, and a buffering chamber. The housing chamber has a first ventilation air inlet to introduce external air into the housing chamber and houses the water electrolysis apparatus. The electric component chamber has a second ventilation air inlet to introduce the external air into the electric component chamber and houses the electric component. The first ventilation air inlet and the second ventilation air inlet are separate from each other. The buffering chamber is in communication with the first ventilation air inlet and the second ventilation air inlet. An air pressure in the buffering chamber is to be maintained at atmospheric pressure.

Water electrolysis system

In a control method of a differential pressure water electrolysis system, a reference water level of a gas-liquid separator for normal operations is set to discharge a liquid water stored in the gas-liquid separator to a discharge tube. A depressurization reference water level which is a lower water level than the reference water level is set to discharge the liquid water stored in the gas-liquid separator to the discharge tube upon depressurizing. A depressurization valve is opened to reduce pressure at a cathode side after operation of a differential pressure water electrolysis device has been stopped, in a state with voltage applied. A permissible water level upper limit value at which an open/close valve is opened is switched from the reference water level to the depressurization reference water level when the depressurization valve is opened.

Control method of differential pressure water electrolysis system

A high differential pressure water electrolysis system includes a high differential pressure water electrolysis device, a water supply tank, a high pressure gas-liquid separator, a hydrogen outlet line, a drain line, a low pressure gas-liquid separator, a water return line, and a pressure maintaining mechanism. The drain line is to drain a liquid water separated by the high pressure gas-liquid separator. The low pressure gas-liquid separator is disposed in the drain line and has a discharge line via which a gas separated by the low pressure gas-liquid separator is to be discharged. The water return line connects the low pressure gas-liquid separator and the water supply tank. The pressure maintaining mechanism is disposed in the discharge line and configured to maintain a pressure in the low pressure gas-liquid separator to be higher than a pressure in the water supply tank.

High differential pressure water electrolysis system and method for starting the same

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.

Method for operating the water electrolysis system

A high pressure water electrolysis system includes a high pressure water electrolysis device, a hydrogen storage device, a high pressure hydrogen pipe, a branch pipe, a non-return valve, a pressure detector, and a controller. The controller includes a threshold storage device, a threshold determination device, and a solenoid valve opening/closing operation device. The threshold storage device is configured to store a first threshold of a pressure value detected by the pressure detector and a second threshold lower than the first threshold. The threshold determination device is configured to determine whether or not the pressure value detected by the pressure detector has reached the second threshold. The solenoid valve opening/closing operation device is configured to open and close a solenoid valve if it is determined that the pressure value detected by the pressure detector has reached the second threshold.

High pressure water electrolysis system and method for activating same

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.

Hydrogen filling system and method of operating the same

Water electrolysis system and method for operating the same

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.

Water electrolysis system and method of operating same

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.

Water electrolysis system and method for shutting down the same

A water electrolysis apparatus applies an electrolysis voltage between current collectors disposed on the respective sides of an electrolyte membrane thereby to electrolyze water to generate oxygen in an anode electrolysis chamber and hydrogen in a cathode electrolysis chamber under a pressure higher than a normal pressure. The water electrolysis apparatus is shut down by applying a voltage between the current collectors after the cathode electrolysis chamber stops supplying the hydrogen, reducing a pressure in at least the cathode electrolysis chamber while the voltage is being applied, and stopping applying the voltage when the pressure in the cathode electrolysis chamber is equal to a pressure in the anode electrolysis chamber.

Method of shutting down water electrolysis apparatus

A method for operating a water electrolysis system includes determining whether or not a water electrolysis apparatus is shut down. The water electrolysis system includes the water electrolysis apparatus, a water circulation apparatus, and a gas-liquid separation apparatus. The water electrolysis apparatus includes power feeders provided on an anode side and a cathode side of an electrolyte membrane. The water electrolysis apparatus generates oxygen on the anode side and generates hydrogen on the cathode side at a higher pressure than a pressure of the oxygen by electrolysis of water. Pressure on the cathode side is released when it is determined that the water electrolysis apparatus is shut down. The water circulation apparatus is operated until a concentration of hydrogen remaining on the anode side is a specified value or less under a condition in which a release of pressure on the cathode side is completed.

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Wako, Japan

Jun Takeuchi