Gas filling method

1. A gas filling method for connecting a tank that stores gas and a supply source that supplies gas by a piping, and filling gas in the tank, the method comprising:

acquiring a pre-start upstream pressure that is a pressure in the supply source side of the piping before the start of the supply of gas;

starting the supply of gas from the supply source after the pre-start upstream pressure is acquired;

acquiring a post-start upstream pressure that is a pressure in the supply source side of the piping after the start of the supply of gas;

acquiring a post-start flowrate that is a flowrate of gas in the same period as a period in which the post-start upstream pressure is acquired;

estimating the pressure loss generated in the piping at the time of the supply of gas by using the pre-start upstream pressure, the post-start upstream pressure, and the post-start flowrate; and

stopping the supply of gas so that a tank pressure that is the pressure in the tank becomes a predetermined target pressure by using the pressure loss,

wherein the post-start upstream pressure is acquired in two or more different acquisition periods defined between a time when the flowrate of gas is 0 and a time when the flowrate of the gas reaches a predetermined target flowrate, and

the post-start flowrate is acquired in the same period as each of the acquisition periods, and the pressure loss generated in the piping at the time of the supply of gas in the piping is estimated by using the pre-start upstream pressure, and the post-start upstream pressure and the post-start flowrate acquired in each of the acquisition periods.

2. The gas filling method according to claim 1 , further comprising:

estimating a tank pressure that is a pressure in the tank during the supply of gas by using the pressure loss; and

estimating a volume of the tank after the supply of the gas is stopped.

3. The gas filling method according to claim 2 , wherein stopping the supply of gas is performed after the gas has been continuously supplied for a predetermined time while the upstream pressure is maintained to be the target pressure.

4. The gas filling method according to claim 2 , wherein stopping the supply of gas is performed so that the estimated tank pressure reaches the target pressure.

5. The gas filling method according to claim 4 , further comprising:

a pre-stop upstream pressure acquisition step for acquiring a pre-stop upstream pressure that is a pressure in the supply source side of the piping before the supply of gas is stopped;

a post-stop upstream pressure acquisition step for acquiring a post-stop upstream pressure that is a pressure in the supply source side of the piping after the supply of gas is stopped;

a pre-stop flowrate acquisition step for acquiring a pre-stop flowrate that is a flowrate of gas at the same period as the acquisition period of the pre-stop upstream pressure; and

a stop-time pressure loss estimation step for estimating the pressure loss generated in the piping at the time of the supply of gas by using the pre-stop upstream pressure, the post-stop upstream pressure, and the pre-stop flowrate.

6. The gas filling method according to claim 2 , further comprising:

receiving volume information of the tank from a vehicle equipped with the tank,

wherein the flowrate of gas is controlled by using the volume information received from the vehicle between starting of the supply of gas and temporarily stopping the supply of gas, and

wherein the flowrate of gas is controlled by using the estimated volume information after the supply of gas is started again after the supply of gas is temporarily stopped. estimated by using the pre-start upstream pressure, and the post-start upstream pressure and the post-start flowrate acquired in each of the acquisition periods.

7. A gas filling method for connecting a tank that stores gas and a supply source that supplies gas by a piping, and filling gas in the tank, the method comprising:

starting the supply of gas from the supply source;

acquiring a pre-stop upstream pressure that is a pressure in the supply source side of the piping before the stop of the supply of gas;

acquiring a pre-stop flowrate that is a flowrate of gas in the same period as a period in which the pre-stop upstream pressure is acquired;

temporarily stopping the supply of gas from the supply source after the pre-stop upstream pressure is acquired;

acquiring a post-stop upstream pressure that is a pressure in the supply source side of the piping after the supply of gas is temporarily stopped;

estimating the pressure loss generated in the piping at the time of the supply of gas by using the pre-stop upstream pressure, the post-stop upstream pressure, and the pre-stop flowrate; and

stopping the supply of gas so that a tank pressure that is a pressure in the tank becomes a predetermined target pressure by using the pressure loss,

wherein the post-start upstream pressure is acquired in two or more different acquisition periods defined between a time when the flowrate of gas is 0 and a time when the flowrate of the gas reaches a predetermined target flowrate, and

the post-start flowrate is acquired in the same period as each of the acquisition periods, and the pressure loss generated in the piping at the time of the supply of gas in the piping is estimated by using the pre-start upstream pressure, and the post-start upstream pressure and the post-start flowrate acquired in each of the acquisition periods.