Propane fuel system thermal management systems and methods

Patent metadata

Field	Value
Publication number	US-12510044-B2
Application number	US-202217815988-A
Country	US
Kind code	B2
Filing date	Jul 29, 2022
Priority date	Jul 29, 2022
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

Systems and methods for thermal management of a propane fuel system are disclosed that include controlling a pressure of a fuel tank so that a fuel supply is available for starting of the engine even during cold ambient conditions.

First claim

What is claimed is:

1 . A method, comprising:
determining a pressure associated with a fuel tank, the fuel tank including a fuel for operating an internal combustion engine, wherein the internal combustion engine is shut down during the determining the pressure; automatically restarting the shut down internal combustion engine in response to the pressure associated with the fuel tank falling to or below a first pressure threshold indicating a restart condition while the internal combustion engine is shut down, the first pressure threshold being above a saturated vapor pressure of the fuel in the fuel tank in which the pressure in the fuel tank is insufficient to supply fuel to the plurality of cylinders, wherein the restart condition maintains a pressure condition of the fuel tank to be able to output a supply of fuel capable of automatically restarting the internal combustion engine; increasing a temperature of the fuel tank with heat generated from operating the automatically restarted internal combustion engine to maintain an engine start capability of the fuel; and automatically shutting down the automatically restarted internal combustion engine in response to the pressure associated with the fuel tank increasing to or above a second pressure threshold that is greater than the first pressure threshold.

2 . The method of claim 1 , wherein increasing the temperature includes circulating a fluid that is heated by operation of the internal combustion engine to heat the fuel tank.

3 . The method of claim 2 , wherein the fluid is a liquid coolant.

4 . The method of claim 3 , wherein the liquid coolant is circulated from the internal combustion engine to the fuel tank and back to the internal combustion engine until the pressure associated with the fuel tank reaches the second pressure threshold.

5 . The method of claim 1 , wherein increasing the temperature of the fuel tank includes circulating the fuel from the fuel tank to the internal combustion engine to be heated by operation of the internal combustion engine.

6 . The method of claim 1 , wherein the first pressure threshold is increased as ambient temperature increases and is decreased as ambient temperature decreases.

7 . The method of claim 1 , further comprising, after automatically shutting down the automatically restarted internal combustion engine, allowing the pressure associated with the fuel tank to decrease from the second pressure threshold to the first pressure threshold while the internal combustion engine is shut down before again automatically restarting the shut down internal combustion engine.

8 . The method of claim 1 , wherein the first pressure threshold is based on an ambient temperature associated with the internal combustion engine.

9 . The method of claim 1 , wherein the first pressure threshold is based on a weather report.

10 . The method of claim 1 , wherein the first pressure threshold is varied based on an operator input.

11 . The method of claim 1 , further comprising shutting down the restarted internal combustion engine and increasing or maintaining the temperature of the fuel tank with heat generated from operation of the shut down internal combustion engine to maintain the engine start capability of the fuel by:
circulating warm coolant from the engine to the fuel tank and back to the internal combustion engine while the internal combustion engine is shut down until a temperature of the coolant drops below a temperature threshold, after which the internal combustion engine is automatically restarted to maintain the pressure condition at or above the first pressure threshold; or circulating fuel from the fuel tank to the internal combustion engine and back to the fuel tank while the internal combustion engine is shut down until a temperature associated with the internal combustion engine drops below a temperature threshold after which the internal combustion engine is automatically restarted to maintain the pressure condition at or above the first pressure threshold.

12 . A system, comprising:
an internal combustion engine including a plurality of cylinders that receive a fuel from a fuel tank, wherein the fuel tank is thermally connected to the internal combustion engine; and a controller configured to receive one or more inputs associated with a pressure of the fuel tank and to automatically start and stop the internal combustion engine, wherein the controller is configured to:
determine the pressure of the fuel tank has fallen at or below a restart pressure threshold indicating a restart condition, the restart pressure threshold being above a saturated vapor pressure of the fuel in the fuel tank in which the pressure in the fuel tank is insufficient to supply fuel to the plurality of cylinders while the internal combustion engine is shut down;
automatically start the shut down internal combustion engine in response to determining the pressure of the fuel tank has fallen at or below the restart pressure threshold while the internal combustion engine is shut down in order to thermally manage the fuel in the fuel tank to maintain an engine start capability of the fuel, wherein the restart pressure threshold maintains a pressure condition of the fuel tank to be able to output a supply of fuel capable of automatically starting the internal combustion engine; and
automatically shut down the automatically started internal combustion engine in response to the pressure associated with the fuel tank increasing to or above a second pressure threshold that is greater than the restart pressure threshold.

13 . The system of claim 12 , wherein, after automatically shutting down the automatically restarted internal combustion engine, the controller is configured to allow the pressure associated with the fuel tank to decrease from the second pressure threshold to the restart pressure threshold whole the internal combustion engine is shut down before automatically starting the shut down internal combustion engine.

14 . The system of claim 12 , wherein the restart pressure threshold varies based on an ambient temperature around the internal combustion engine or a weather input into the controller.

15 . The system of claim 12 , wherein the restart pressure threshold is modifiable by an operator selected input.

16 . The system of claim 12 , further comprising:
a cooling system including a coolant for receiving heat from the operation of the internal combustion engine, wherein the controller is configured to operate an electric pump to circulate coolant to the fuel tank to thermally manage the fuel in the fuel tank after the internal combustion engine is restarted, wherein the controller is further configured to operate the electric pump to continue circulate coolant to the fuel tank to thermally manage the fuel tank at or above the restart pressure threshold after the internal combustion engine is shut down until a temperature of the coolant drops below a temperature threshold, after which the controller is configured to automatically restart the internal combustion engine to maintain the pressure condition at or above the restart pressure threshold.

17 . The system of claim 16 , wherein the controller is configured to stop circulation of coolant to the fuel in the fuel tank while the pressure of the fuel tank is at or above the second pressure threshold.

18 . The system of claim 12 , further comprising:
a fuel circulation loop configured to circulate fuel from the fuel tank to the internal combustion engine to receive heat from the operation of the in

Assignees

• Cummins Inc

Inventors

• Perfetto Anthony Kyle
• Geckler Samuel C

Classifications

• F02M31/183

  Control · CPC title

• F02M21/0227

  Means to treat or clean gaseous fuels or fuel systems, e.g. removal of tar, cracking, reforming or enriching · CPC title

• F02M21/0215

  Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas · CPC title

• F02M21/06

  Apparatus for de-liquefying, e.g. by heating · CPC title

• F02M31/14 Primary

  by using heat from working cylinders or cylinder heads · CPC title