System and method for delivering a fluid stored in liquefied form to an end user in gaseous form

Patent metadata

Field	Value
Publication number	US-2016265478-A1
Application number	US-201415032587-A
Country	US
Kind code	A1
Filing date	Oct 23, 2014
Priority date	Oct 31, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

A system and method is disclosed for storing a fluid in a storage vessel in liquefied form and delivering it in gaseous form to an end user through a supply line. The system comprises a pressure relief circuit for returning the fluid from the supply line to the vessel when predetermined conditions are met. The pressure relief circuit comprises a return line connected to the supply line and the storage vessel, a diversion line to divert the fluid elsewhere and a switching device operable to direct the fluid to either one of the lines, as a function of predetermined conditions.

First claim

1 . A system for delivering a fluid stored in liquefied form to an end user in a gaseous form, the system comprising:
a storage vessel; a supply line in fluid communication with said storage vessel and said end user; and a pressure relief circuit comprising
(i) a return line in fluid communication with said supply line and said storage vessel for returning said fluid in gaseous form from said supply line to said storage vessel;
(ii) a diversion line in fluid communication with said supply line; and
(iii) a switching device operable to direct said fluid in gaseous form from said supply line to said return line when pressure within said supply line is greater than a predetermined threshold pressure and when predetermined conditions are met, and to said diversion line when said pressure within said supply line is lower than said predetermined threshold pressure or said predetermined conditions are not met.

2 .- 11 . (canceled)

12 . A system for delivering a fluid stored in liquefied form to an end user in a gaseous form, the system comprising:
a storage vessel; a supply line in fluid communication with said storage vessel and said end user; a pressure relief circuit comprising a switching device operated by a controller to direct said fluid from said supply line and; return said fluid in said gaseous form to said storage vessel through a return line when a parameter of said fluid meets a predetermined condition; or divert said fluid to a diversion line when said parameter of said fluid does not meet said predetermined condition.

13 . The system of claim 12 wherein said controller is programmed to operate said switching device such that it diverts said fluid in said gaseous form to said diversion line which fluidly connects to at least one of a treatment device before venting to at least one of atmosphere, a secondary user, and a re-liquefication device.

14 . The system of claim 12 further comprising a sensor disposed in a relief line between said supply line and said switching device to measure said parameter of said fluid.

15 . The system according to claim 12 further comprising a filter disposed in said return line.

16 . The system of claim 13 further comprising a gas separator disposed in said diversion line whereby gases are separated from liquid and solid contaminants so that only gases are vented through said diversion line.

17 . The system of claim 12 wherein said controller is programmed to control said switching device such that said fluid in gaseous form is diverted through a diversion line when the pressure of said fluid in said gaseous form is lower than the pressure in said storage vessel.

18 . The system of claim 12 wherein said controller is programmed to operate said switching device such that said fluid in gaseous form is returned to said storage vessel through said return line if by returning said fluid in gaseous form to said storage vessel the pressure of said storage vessel remains below the threshold safety pressure of said vessel.

19 . The system of claim 12 wherein said controller is programmed to control said switching device such that said fluid in gaseous form is returned to said storage vessel through said return line if diagnostics from said controller indicate that said fluid in said gaseous form is free of contaminants.

20 . The system of claim 12 herein said fluid is a fuel that is in gaseous form at standard pressure and temperature and said end user is an internal combustion engine.

21 . The system of claim 20 wherein said fuel is delivered through said supply line to a fuel injection valve for injecting said fuel directly into an engine combustion chamber.

22 . The system of claim 20 wherein said controller is programmed to control said switching device to return said fluid in gaseous form to said storage vessel after a predetermined time has elapsed since said engine has stopped running in a liquid-only fueled mode.

23 . The system of claim 20 further comprising a gas separator disposed in said pressure relief circuit and a liquid outlet from said gas separator directs liquid separated from said gas to a liquid fuel return line in fluid communication with a liquid fuel tank.

24 . A method comprising:
storing a fluid in a vessel in liquefied form; delivering said fluid in gaseous form through a supply line to an end user; reducing fluid pressure in said supply line upon meeting predetermined conditions, by returning fluid in gaseous form from said supply line to said vessel; and diverting said fluid elsewhere upon not meeting said predetermined conditions.

25 . The method of claim 24 further comprising determining fluid pressure in said supply line and diverting said fluid elsewhere when said fluid pressure is determined to be higher than a predetermined high pressure threshold.

26 . The method of claim 24 further comprising determining fluid pressure in said supply line and diverting said fluid elsewhere when said fluid pressure is determined to be lower than a predetermined low pressure threshold.

27 . The method of claim 24 wherein at least one of said predetermined conditions correlates to keeping the pressure inside said storage vessel below a threshold safety pressure of said vessel.

28 . The method of claim 24 wherein at least one of said predetermined conditions correlates to the pressure inside said storage vessel being less than a preset storage vessel relief pressure by a predetermined margin.

29 . The method of claim 24 further comprising diagnosing whether said fluid contains contaminants and diverting said fluid elsewhere when contaminants are detected.

30 . The method of claim 24 wherein said end user is an internal combustion engine and said method further comprises delaying to return said fluid to said storage vessel until a predetermined time has elapsed since said engine has stopped running in a liquid-only fueled mode.

31 . The system of claim 12 wherein said supply line delivers said fluid to a second storage vessel.

32 . The system of claim 12 further comprising a gas separator disposed between said supply line and said switching device for separating gases from liquid and solid contaminants whereby a gas outlet from said gas separator is fluidly connected to said switching device.

33 . The system of claim 12 further comprising a gas separator having a liquid outlet through which said liquid contaminants flow to a liquid fuel tank through a liquid fuel return line.

Assignees

• Westport Power Inc

Inventors

• Oversby Kevin K

Classifications

• F17C2221/033

  Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG · CPC title

• F17C2205/0326

  electrically actuated · CPC title

• F17C2205/0347

  Active charcoal type · CPC title

• F17C2260/035

  of fluid · CPC title

• F17C2223/046

  in the liquid · CPC title