Tank gauging apparatus and method

• US 4,956,996 A
• Filed: 08/18/1989
• Issued: 09/18/1990
• Est. Priority Date: 07/11/1988
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Morris, Brian G.
• Primary Examiner(s): Raevis, Robert
• Application Number:
  US07/396,726
• Time in Patent Office: 396 Days
• Field of Search: 73/149
• US Class Current: 73/149
• CPC Class Codes: B64G 1/402 Propellant tanks; Feeding propellants
• CPC Class Codes: F17C 13/008 for use under microgravity conditions
• CPC Class Codes: F17C 2201/0157 Polygonal
• CPC Class Codes: F17C 2205/0338 Pressure regulators
• CPC Class Codes: F17C 2227/0114 with vacuum injectors, e.g. venturi
• CPC Class Codes: F17C 2250/032 using computers
• CPC Class Codes: F17C 2250/043 Pressure
• CPC Class Codes: F17C 2250/0439 Temperature
• CPC Class Codes: F17C 2250/0495 the indicated parameter is a converted measured parameter
• CPC Class Codes: F17C 2270/0194 for use under microgravity conditions, e.g. space
• CPC Class Codes: F17C 2270/0197 Rockets
• CPC Class Codes: G01F 17/00 Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies measuring linear dimensions to determine volume G01B
• CPC Class Codes: G01F 23/14 by measurement of pressure

Abstract

Apparatus for gauging the amount of liquid in a container of liquid and gas under low or zero gravity net conditions includes an accumulator and appropriate connector apparatus for communicating gas between the accumulator and the container. In one form of the invention, gas is removed from the container and compressed into the accumulator. The pressure and temperature of the fluid in the container is measured before and after removal of the gas; the pressure and temperature of gas in the accumulator is measured before and after compression of the gas into the accumulator from the container. These pressure and temperature measurements are used in determining the volume of gas in the container, whereby the volume of liquid in the container can be determined from the difference between the known volume of the container and the volume of gas in the container. Gas from the accumulator may be communicated into the container in a similar process as a verification of the gauging of the liquid volume, or as an independent process for determining the volume of liquid in the container.

Claims

1. A method of gauging the amount of liquid in a container of liquid and gas in low or zero gravity net conditions, comprising the following steps:

a. providing a closed fluid system comprising an accumulator for receiving gas removed from said container, a compressor for pumping said gas from said container into the accumulator, and means for selectively connecting the compressor and accumulator to the container;

b. determining the pressure and temperature of fluid in the container and of gas in the accumulator;

c. pumping gas from the container into the accumulator;

d. determining the pressure and temperature of fluid in the container and of gas in the accumulator; and

e. utilizing the pressure and temperature values to determine the volume of gas in the container, and determining the volume of liquid in the container from the difference between the volume of the container and the volume of the gas in the container, whereby the closed system precludes the need of an external gas source, and subsequent volume determinations are made after gas is transferred from the accumulator to the container.

2. A method as defined in claim 1 further comprising the steps of providing a radiator and, with said radiator, removing the heat of compression of gas pumped into the accumulator.

3. A method as defined in claim 1 further comprising the steps of providing control means and, with the control means, operating said compressor.

4. A method of gauging the amount of liquid in a container of liquid and gas in low or zero gravity net conditions, comprising the following steps:

a. providing a closed fluid system comprising an accumulator for receiving gas removed from said container, a compressor for pumping said gas from said container into the accumulator, and means for selectively connecting the compressor and accumulator to the container;

b. determining the pressure and temperature of fluid in the container and of gas in the accumulator;

c. pumping gas from the container into the accumulator;

d. determining the pressure and temperature of fluid in the container and of gas in the accumulator;

e. utilizing the pressure and temperature values to determine the volume of gas in the container, and determining the volume of liquid in the container from the difference between the volume of the container and the volume of the gas in the container;

f. determining the pressure and temperature of fluid in the container and of gas in the accumulator;

g. communicating gas from the accumulator to the container;

h. determining the pressure and temperature of fluid in the container and of gas in the accumulator; and

i. utilizing the pressure and temperature values to determine the volume of gas in the container, and determining the volume of liquid in the container from the difference between the volume of the container and the volume of the gas in the container.

5. A method as defined in claim 4 wherein steps f. through i. are delayed until after the amount of liquid in the container is changed.

6. A method of gauging the amount of liquid in a container of liquid and gas in low or zero gravity net conditions, comprising the following steps:

a. providing a separator at the container for providing rotation of fluid within the container to separate gas from the liquid therein and for communicating gas out of the container, an accumulator for receiving gas removed from said container, a compressor for pumping said gas from said container into the accumulator, and means for selectively connecting the compressor and accumulator to the container;

b. determining the pressure and temperature of fluid in the container and of gas in the accumulator;

c. pumping gas from the container into the accumulator;

d. determining the pressure and temperature of fluid in the container and of gas in the accumulator; and

e. utilizing the pressure and temperature values to determine the volume of gas in the container, and determining the volume of liquid in the container from the difference between the volume of the container and the volume of the gas in the container.