Method for measuring fluid level in liquid hydrogen tank and liquid hydrogen storage system

Patent metadata

Field	Value
Publication number	US-11092290-B2
Application number	US-201916672614-A
Country	US
Kind code	B2
Filing date	Nov 4, 2019
Priority date	Dec 27, 2018
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

An amount Y of liquid hydrogen that has passed through a first valve and has been volatilized during a predetermined time after first and second valves are opened is calculated by using a pressure P0 in an internal space of a liquid hydrogen tank measured before the two valves are opened, a pressure P1 in the internal space measured after the lapse of the predetermined time since the two valves are opened, and an amount X of the gaseous hydrogen that has passed through the second valve during the predetermined time. A fluid level H of the liquid hydrogen in the liquid hydrogen tank after the lapse of the predetermined time since the two valves are opened is calculated by using a expression showing a relationship between the H and an amount Y1 of the liquid hydrogen that passes through the first valve and drops therefrom, and the Y.

First claim

What is claimed is:

1. A method for measuring a fluid level in a liquid hydrogen tank performed in a liquid hydrogen storage system,
the liquid hydrogen storage system comprising:
the liquid hydrogen tank configured so that liquid hydrogen can be injected and stored therein;
a liquid hydrogen dispensing pipe disposed vertically below the liquid hydrogen tank and configured to dispense the liquid hydrogen from the liquid hydrogen tank;
a first adjustment valve disposed at a midway point of the liquid hydrogen dispensing pipe and configured to adjust an amount of the liquid hydrogen dispensed from the liquid hydrogen tank;
a heat exchanger connected to the liquid hydrogen dispensing pipe;
a gaseous hydrogen supply pipe configured to supply gaseous hydrogen that has passed through the heat exchanger to a downstream side;
a second adjustment valve disposed at a midway point of the gaseous hydrogen supply pipe and configured to adjust an amount of the gaseous hydrogen supplied to the downstream side;
a gaseous hydrogen recirculation pipe configured to recirculate the gaseous hydrogen that has passed through the heat exchanger to an internal space of the liquid hydrogen tank;
a pressure gauge configured to measure a pressure in the internal space of the liquid hydrogen tank; and
a gas flowmeter configured to measure an amount of the gaseous hydrogen that has passed through the second adjustment valve and has been supplied to the downstream side,
the method comprising:
a volatilization amount calculation step of calculating an amount Y of the liquid hydrogen that has passed through the first adjustment valve and has been volatilized during a predetermined time after the first and second adjustment valves are opened by using a pressure P 0 in the internal space of the liquid hydrogen tank that is measured before the first and second adjustment valves are opened, a pressure P 1 in the internal space of the liquid hydrogen tank that is measured after the lapse of the predetermined time since the first and second adjustment valves are opened, and an amount X of the gaseous hydrogen that has passed through the second adjustment valve and has been supplied to the downstream side during the predetermined time; and
a fluid level calculation step of calculating a fluid level H of the liquid hydrogen in the liquid hydrogen tank after the lapse of the predetermined time since the first and second adjustment valves are opened by using a relational expression showing a relationship between the fluid level H of the liquid hydrogen in the liquid hydrogen tank and an amount Y 1 of the liquid hydrogen that passes through the first adjustment valve and drops therefrom, and the amount Y of the liquid hydrogen obtained in the volatilization amount calculation step.

2. The method for measuring the fluid level in the liquid hydrogen tank according to claim 1 , wherein the volatilization amount calculation step comprises:
calculating an amount n 0 of the gaseous hydrogen present in the internal space of the liquid hydrogen tank before the first and second adjustment valves are opened by using the pressure P 0 ;
measuring an amount n 1 of the gaseous hydrogen present in the internal space of the liquid hydrogen tank after the lapse of the predetermined time since the first and second adjustment valves are opened by using the amount P 1 ;
calculating an amount Δn of an increase in the gaseous hydrogen in the internal space of the liquid hydrogen tank during the predetermined time by subtracting the amount n 0 from the amount n 1 ; and
calculating the amount Y by adding the amount Δn to the amount X.

3. The method for measuring the fluid level in the liquid hydrogen tank according to claim 1 , wherein in the fluid level calculation step, the fluid level H after the lapse of the predetermined time since the first and second adjustment valves are opened is calculated by substituting the amount Y obtained in the volatilization amount calculation step for the amount Y 1 in the relational expression.

4. A liquid hydrogen storage system comprising:
a liquid hydrogen tank configured so that liquid hydrogen can be injected and stored therein;
a liquid hydrogen dispensing pipe disposed vertically below the liquid hydrogen tank and configured to dispense the liquid hydrogen from the liquid hydrogen tank;
a first adjustment valve disposed at a midway point of the liquid hydrogen dispensing pipe and configured to adjust an amount of the liquid hydrogen dispensed from the liquid hydrogen tank;
a heat exchanger connected to the liquid hydrogen dispensing pipe;
a gaseous hydrogen supply pipe configured to supply gaseous hydrogen that has passed through the heat exchanger to a downstream side;
a second adjustment valve disposed at a midway point of the gaseous hydrogen supply pipe and configured to adjust an amount of the gaseous hydrogen supplied to the downstream side;
a gaseous hydrogen recirculation pipe configured to recirculate the gaseous hydrogen that has passed through the heat-exchanger to an internal space of the liquid hydrogen tank;
a pressure gauge configured to measure a pressure in the internal space of the liquid hydrogen tank;
a gas flowmeter configured to measure an amount of the gaseous hydrogen that has passed through the second adjustment valve and has been supplied to the downstream side; and
a control unit,
wherein the control unit performs:
a volatilization amount calculation process of calculating an amount Y of the liquid hydrogen that has passed through the first adjustment valve and has been volatilized during a predetermined time after the first and second adjustment valves are opened by using a pressure P 0 in the internal space of the liquid hydrogen tank that is measured before the first and second adjustment valves are opened, a pressure P 1 in the internal space of the liquid hydrogen tank that is measured after the lapse of the predetermined time since the first and second adjustment valves are opened, and an amount X of the gaseous hydrogen that has passed through the second adjustment valve and has been supplied to the downstream side during the predetermined time; and
a fluid level calculation process of calculating a fluid level H of the liquid hydrogen in the liquid hydrogen tank after the lapse of the predetermined time since the first and second adjustment valves are opened by using a relational expression showing a relationship between the fluid level H of the liquid hydrogen in the liquid hydrogen tank and an amount Y 1 of the liquid hydrogen that passes through the first adjustment valve and drops therefrom, and the amount Y of the liquid hydrogen obtained in the volatilization amount calculation process.

Assignees

• Toyota Motor Co Ltd

Inventors

• Takahashi Takaaki
• Yamashita Osamu

Classifications

• G01F23/804

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• F17C2270/0184

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• F17C2250/0495

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• F17C2203/0391

  by vacuum · CPC title

• F17C7/02

  Discharging liquefied gases · CPC title