Fuel cooled injector tip

Patent metadata

Field	Value
Publication number	US-9897053-B2
Application number	US-201615235189-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Aug 12, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A fuel injector is provided comprising an outer housing, a nozzle housing disposed within the outer housing, a flow path between the outer housing and the nozzle housing, the flow path being coupled to a low pressure fuel source, and a circumferential gap in flow communication with the flow path and extending about a tip of the fuel injector between an outer surface of the nozzle housing and an inner surface of a combustion shield adjacent the injector tip. The circumferential gap is in flow communication with a drain gap between the outer housing and a bore for receiving the fuel injector, the drain gap routing the low pressure fuel away from the injector tip.

First claim

We claim:

1. A fuel injector, comprising:
an outer housing;
a nozzle housing disposed within the outer housing;
a flow path between the outer housing and the nozzle housing, the flow path being coupled to a low pressure fuel source; and
a circumferential gap in flow communication with the flow path and extending about a tip of the fuel injector between an outer surface of the nozzle housing and an inner surface of a combustion shield adjacent the injector tip;
wherein the circumferential gap is in flow communication with a drain gap between the outer housing and a bore for receiving the fuel injector, the drain gap routing the low pressure fuel away from the injector tip.

2. The fuel injector of claim 1 , wherein the outer surface of the nozzle housing includes a first shoulder that contacts the combustion shield to define one end of the circumferential gap, and a second shoulder that contacts the combustion shield to define another end of the circumferential gap, the other end of the circumferential gap having an opening in flow communication with the flow path.

3. The fuel injector of claim 2 , wherein the drain gap is in flow communication with the circumferential gap at a location between the ends of the circumferential gap.

4. The fuel injector of claim 1 , wherein the nozzle housing comprises at least one injector orifice positioned at a distal end of the nozzle housing, the injector orifice being in flow communication with a high pressure fuel source to controllably inject fuel into a cylinder of an engine.

5. The fuel injector of claim 1 , further comprising an O-ring disposed between the outer housing and the bore, the drain gap being disposed between the injector tip and the O-ring.

6. A method for cooling a fuel injector in a dual fuel engine application, comprising:
providing low pressure diesel fuel to a double walled segment coupled to a plurality of fuel injectors;
routing the low pressure diesel fuel from the double walled segment through a flow path between an injector nozzle housing and an injector outer housing;
routing the low pressure diesel fuel from the flow path through a circumferential gap extending about a tip of the fuel injector between an outer surface of the injector nozzle housing and an inner surface of a combustion shield adjacent the injector tip; and
draining the low pressure diesel fuel from the circumferential gap through a drain line coupled to a fuel tank.

7. The method of claim 6 , wherein routing the low pressure diesel fuel from the flow path through a circumferential gap comprises routing the low pressure fuel through an opening defined at one end of the circumferential gap by a shoulder of the outer surface of the nozzle housing and an inner surface of the combustion shield.

8. The method of claim 6 , wherein the drain line is in flow communication with the circumferential gap at a location between ends of the circumferential gap.

9. A fuel injector, comprising:
an outer housing;
a nozzle housing disposed within the outer housing;
a flow path between the outer housing and the nozzle housing, the flow path being coupled to a low pressure fuel source;
a circumferential gap in flow communication with the flow path and extending along an upper surface of a combustion shield adjacent the injector tip; and
an opening extending through the outer housing having one end in flow communication with the circumferential gap and another end in flow communication with a drain gap formed between the outer housing and a bore for receiving the fuel injector, the drain gap routing the low pressure fuel away from the injector tip.

10. The fuel injector of claim 9 , wherein the nozzle housing comprises at least one injector orifice positioned at a distal end of the nozzle housing, the injector orifice being in flow communication with a high pressure fuel source to controllably inject fuel into a cylinder of an engine.

11. The fuel injector of claim 9 , further comprising an O-ring disposed between the outer housing and the bore, the drain gap being disposed between the injector tip and the O-ring.

12. A method for cooling a fuel injector in a dual fuel engine application, comprising:
providing low pressure diesel fuel to a double walled segment coupled to a plurality of fuel injectors;
routing the low pressure diesel fuel from the double walled segment through a flow path between an injector nozzle housing and an injector outer housing;
routing the low pressure diesel fuel from the flow path through a circumferential gap extending along an upper surface of a combustion shield adjacent an injector tip; and
draining the low pressure diesel fuel from the circumferential gap through a drain line coupled to a fuel tank.

13. The method of claim 12 , wherein providing low pressure diesel fuel to a double walled segment comprises providing the low pressure fuel to an outer line of the double walled segment surrounding an inner line of the double walled segment.

14. The method of claim 13 , further comprising providing high pressure fuel to the inner line of the double walled segment.

15. The method of claim 12 , wherein routing the low pressure diesel fuel from the double walled segment through a flow path comprises routing the low pressure fuel from the double walled segment through a T-fitting coupled to one of the plurality of fuel injectors.

16. The method of claim 12 , further comprising using a control module to control operation of the plurality of fuel injectors.

17. The method of claim 16 , wherein using a control module to control operation of the plurality of fuel injectors comprises responding to an engine shut down when a fuel injector operating temperature is above a predetermined high temperature threshold by causing the flow of low pressure diesel fuel to the plurality of fuel injectors to discontinue.

18. The method of claim 16 , wherein using a control module to control operation of the plurality of fuel injectors comprises responding to an engine shut down when a fuel injector operating temperature is above a predetermined high temperature threshold by activating a pumping device coupled to the circumferential gap to pump low pressure diesel fuel from the circumferential gap.

19. The method of claim 16 , wherein using a control module to control operation of the plurality of fuel injectors comprises responding to an engine shut down when a fuel injector operating temperature is above a predetermined high temperature threshold by activating a pump for a period of time following engine shut down to pump low pressure diesel fuel through the circumferential gap to cool the injector tip.

20. The method of claim 16 , wherein using a control module to control operation of the plurality of fuel injectors comprises responding to an engine shut down when a fuel injector operating temperature is above a predetermined high temperature threshold by causing the engine to idle for a period of time prior to actually shutting down the engine to permit the plurality of fuel injectors to cool before shut down.

21. The method of claim 20 , wherein the period of time is one of a predetermined period of time or a period of time that depends upon a difference between the fuel injector operating temperature and the predetermined high temperature threshold.

22. A method for cooling a fuel injector, comprising:
using a control module to respond to an engine shut down when an operating temperature of a fuel injector of an engine is above a high temperature t

Assignees

• Cummins Inc

Inventors

• Kolhouse Steven J
• Primus Raymond V
• Peters Lester L
• Buchanan David L

Classifications

• F02D41/3854

  with elements in the low pressure part, e.g. low pressure pump · CPC title

• F02D2200/0606

  Fuel temperature · CPC title

• F02M37/0052

  Details on the fuel return circuit; Arrangement of pressure regulators · CPC title

• F02D41/08

  for idling (F02D41/06, F02D41/16 take precedence) · CPC title

• F02D41/042

  for stopping the engine · CPC title