Method and system for delivering a gaseous fuel into the air intake system of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9897055-B2
Application number	US-201415037622-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Nov 21, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A method and system is disclosed for delivering a cryogenically stored fuel in a gaseous state into the air intake system of a gaseous fuelled internal combustion engine. The method comprises determining the flow rate capacity in the engine system's fuel delivery line, comparing the determined flow rate capacity to a required flow rate demand and supplying fuel in gaseous state directly from the vapor space of the cryogenic storage vessel to the fuel delivery line that supplies fuel to the engine, when the flow rate capacity is equal to or higher than the required flow rate demand. The method further comprises activating a cryogenic pump to deliver fuel to the internal combustion engine from the liquid space of the cryogenic storage vessel when the determined flow rate capacity is lower than the required flow rate demand.

First claim

We claim:

1. A method for delivering a fuel in a gaseous state into an air intake system of a gaseous fuelled internal combustion engine, said method comprising:
determining a required fuel flow rate demand according to an operating condition of said internal combustion engine;
determining a flow rate capacity in a fuel supply system of said internal combustion engine;
comparing said flow rate capacity to said required flow rate demand; and
supplying said fuel in said gaseous state from said vapor space in said storage vessel when said flow capacity is equal to or higher than said required flow rate demand; or
activating a fuel pump and delivering fuel from a liquid space in said storage vessel when said flow rate capacity is lower than said required flow rate demand.

2. The method of claim 1 wherein determining said required flow rate demand is determined as a function of engine operating conditions.

3. The method of claim 2 wherein said required flow rate demand is determined based on an engine speed and torque.

4. The method of claim 1 wherein the step of activating said fuel pump comprises supplying hydraulic fluid from a hydraulic pump to a hydraulic drive unit that drives said fuel pump.

5. The method of claim 4 wherein said hydraulic pump is a first one of at least two hydraulic pumps, the method further comprising electrically activating at least one additional hydraulic pump to deliver hydraulic fluid to said hydraulic drive unit when a commanded hydraulic fluid flow rate is higher than that which can be supplied by said first one of at least two hydraulic pumps.

6. The method of claim 1 further comprising increasing the temperature of said fuel by flowing it through a heat exchanger.

7. The method of claim 1 wherein said storage vessel is a first one of a plurality of storage vessels each having a respective vapor space and a liquid space, said method further comprising:
supplying said fuel from said vapor space of any one of said plurality of storage vessels when said flow rate capacity is higher than said flow rate demand; or
activating said fuel pump and supplying said fuel from one of said plurality of storage vessels when said flow rate capacity is lower than said flow rate demand.

8. The method of claim 7 , said method further comprising measuring the amount of fuel in each of said plurality of storage vessels and, when activating said fuel pump, supplying said fuel from one of said plurality of storage vessels that has the most of said fuel.

9. The method of claim 1 wherein said storage vessel is a first one of a plurality of storage vessels each having a respective vapor space and liquid space, and each having a respective fuel pump, said method further comprising:
supplying said fuel from said vapor space of any one of said plurality of storage vessels when said flow rate capacity is higher than said flow rate demand; or
selecting and activating one of said fuel pumps and supplying said fuel from an associated one of said plurality of storage vessels when said flow rate capacity is lower than said flow rate demand.

10. The method of claim 9 wherein selecting one of said fuel pumps that is to be activated is determined by operating each one of said fuel pumps in sequential order.

11. The method of claim 9 wherein selecting one of said fuel pumps that is to be activated is determined by measuring the amount of fuel in each one of said plurality of storage vessels and selecting the one of said plurality of fuel pumps that is associated with the storage vessel that has the most of said fuel.

12. The method of claim 9 further comprising increasing the temperature of said fuel by flowing it through a heat exchanger associated with a respective storage vessel from which fuel is supplied to said internal combustion engine.

13. A method of claim 1 further comprising:
measuring a pressure in said fuel supply system;
comparing said measured pressure in said fuel supply system with a required supply pressure at start-up; and
activating said fuel pump when said pressure in said fuel supply system is lower than said required supply pressure at start-up.

14. A system for delivering a fuel in a gaseous state into an air intake system of a gaseous fuelled internal combustion engine, said system comprising:
a. a storage vessel for holding said fuel;
b. a fuel pump fluidly connected to receive fuel from a liquid space of said storage vessel;
c. a liquid supply line in fluid communication with a discharge outlet of said fuel pump for delivering fuel from said discharge outlet of said fuel pump to a delivery line which delivers fuel to said internal combustion engine;
d. a vapor supply line in fluid communication with a vapor space of said storage vessel for delivering fuel in a gaseous state from said vapor space to said delivery line;
e. a pressure sensor for measuring pressure in said delivery line; and
f. a controller which receives pressure measurements from said pressure sensor, determines a fuel flow capacity in said delivery line, determines a required fuel flow rate demand according to an operating condition of said internal combustion engine and compares said flow capacity in said delivery line to said required flow rate demand, wherein said controller commands said fuel pump to operate when said flow rate capacity is lower than said required flow rate demand.

15. The system of claim 14 further comprising a heat exchanger placed in said delivery line for increasing the temperature of said fuel being supplied to said internal combustion engine.

16. The system of claim 14 further comprising a hydraulic pump which supplies hydraulic fluid to a hydraulic drive unit that drives said fuel pump.

17. The system of claim 16 wherein said hydraulic pump is a first one of at least two hydraulic pumps which can be electrically activated to deliver hydraulic fluid to said hydraulic drive unit that drives said fuel pump.

18. The system of claim 14 wherein said fuel pump is disposed within a cryogenic space of said storage vessel.

19. The system of claim 14 wherein said storage vessel is a first one of a plurality of storage vessels each having a respective vapor space and a liquid space, and being fluidly connected to said fuel pump, and wherein said controller is programmed to activate said fuel pump to supply fuel from said liquid space of one of said plurality of storage vessels when said flow rate capacity is lower than said flow rate demand.

20. The system of claim 14 wherein said storage vessel is a first one of a plurality of storage vessels each having a respective vapor space and a liquid space, and each being fluidly connected to a respective fuel pump, and wherein said controller is programmed to select and activate one of said fuel pumps and supply fuel from one of said plurality of storage vessels which is associated with said activated fuel pump when said flow rate capacity is lower than said flow rate demand.

Assignees

• Westport Power Inc

Inventors

• Batenburg Gregory A
• Bengali Anuja S
• Garner Gage

Classifications

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F17C2227/0178

  in the vessel · CPC title

• F17C2250/0443

  Flow or movement of content · CPC title

• F17C2250/0626

  Pressure · CPC title

• F17C2250/03

  Control means · CPC title