Sampling apparatus and sampling method

A sampling method for taking a sample of hydrogen gas to a cylinder from a storage container of fuel hydrogen gas to be supplied to a hydrogen vehicle by using a sampling apparatus including a pressure-reducing safety unit and a cylinder unit,

• wherein the pressure-reducing safety unit includes a device accommodation chamber that accommodates devices and a cylinder connection chamber in which a flexible hose for sampling is connectable to the cylinder,
• wherein the device accommodation chamber accommodates a supply pipe that introduces high-pressure hydrogen gas from the storage container, a safety pipe that discharges hydrogen gas in the supply pipe when a pressure of the hydrogen gas exceeds a set pressure, and a discharge pipe that discharges gas in a pipe extending from the supply pipe to the cylinder,
• wherein a hydrogen inlet from the storage container is disposed at one end of the supply pipe, a hydrogen outlet to the cylinder is disposed at the other end of the supply pipe, and the hydrogen outlet is located near a boundary between the device accommodation chamber and the cylinder connection chamber,
• wherein a pressure-reducing valve that reduces a pressure of the high-pressure hydrogen gas introduced from the hydrogen inlet and a flow control valve that adjusts a flow rate of the hydrogen gas whose pressure has been reduced by the pressure-reducing valve are disposed in the supply pipe,
• wherein the safety pipe and the discharge pipe, in which a discharge on-off valve is disposed, branch from a branching portion of the supply pipe between the pressure-reducing valve and the flow control valve,
• wherein a main valve, a rupture disk that opens the safety pipe at a first set pressure or higher, and a safety valve that opens at a second set pressure lower than the first set pressure and closes at a third set pressure lower than the second set pressure are disposed in the safety pipe in order from the branching portion of the supply pipe,
• wherein the cylinder connection chamber includes an open surface portion that opens toward the outside, and
• wherein the cylinder unit removably accommodates the cylinder, excluding an exposed portion where a front end portion of the cylinder, a mouthpiece, and a cylinder on-off valve are exposed, in an openable/closable casing,
• the sampling method comprising:
• inserting the exposed portion of the cylinder into the cylinder connection chamber from the open surface portion of the cylinder connection chamber, connecting the mouthpiece of the cylinder and the hydrogen outlet by using the flexible hose, and connecting the hydrogen inlet to a filling hole of the storage container;
• filling an inside of the supply pipe and an inside of the flexible hose with residual hydrogen gas in the cylinder by opening the cylinder on-off valve and the flow control valve, subsequently stopping the filling by closing the cylinder on-off valve, and discharging gas by opening a discharge on-off valve;
• and
• starting filling an inside of the cylinder from the storage container by closing the discharge on-off valve and opening the cylinder on-off valve to take the sample of hydrogen gas into the cylinder.