System and method for supplying natural gas to dual fuel engine

Patent metadata

Field	Value
Publication number	US-9638118-B2
Application number	US-201514681400-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Apr 8, 2015
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A natural gas system for an intake manifold of a dual fuel engine is provided. The natural gas system includes a heat exchanger configured to exchange heat with a first stream of natural gas passing therethrough. The natural gas system further includes a temperature regulating assembly positioned downstream of the heat exchanger with respect to the first stream of the natural gas. The temperature regulating assembly includes a conduit having an inlet and an outlet. The temperature regulating assembly also includes a supply line in selective fluid communication with the conduit. The temperature regulating assembly further includes a temperature sensing assembly provided within the conduit. Further, the introduction of the second stream is based on a temperature of the natural gas within the conduit.

First claim

What is claimed is:

1. A natural gas system for an intake manifold of a dual fuel engine, the natural gas system comprising:
a feed line structured to receive a flow of natural gas from a tank and to divide the flow of natural gas into a first stream of natural gas and a second stream of natural gas;
a heat exchanger configured to receive the first stream of natural gas from the feed line and to exchange heat with the first stream of natural gas passing therethrough; and
a temperature regulating assembly positioned downstream of the heat exchanger with respect to the first stream of the natural gas, the temperature regulating assembly comprising:
a conduit having an inlet configured to receive the first stream of natural gas and an outlet;
a supply line in fluid communication with the feed line upstream of the heat exchanger and in selective fluid communication with the conduit between the inlet and the outlet of the conduit, the supply line configured to receive the second stream of natural gas from the feed line and to introduce the second stream of natural gas into the conduit, wherein a temperature of the second stream is lower than a temperature of the first stream; and
a temperature sensing assembly provided within the conduit,
wherein the introduction of the second stream is based on a temperature of the natural gas within the conduit.

2. The natural gas system of claim 1 further comprising a port associated with the conduit, wherein the second stream of the natural gas is introduced into the conduit based on an opening of the port.

3. The natural gas system of claim 2 further comprising a cover element associated with the port, wherein the opening of the port is based on a movement of the cover element.

4. The natural gas system of claim 1 , wherein the temperature sensing assembly comprises a sensing element configured to any one of expand and contract based on the temperature of the natural gas within the conduit.

5. The natural gas system of claim 4 , wherein the sensing element is configured to selectively expand along a diameter of the conduit based on the temperature of the natural gas within the conduit.

6. The natural gas system of claim 4 , wherein the sensing element includes a wax pellet.

7. The natural gas system of claim 1 , wherein the supply line is connected upstream of the heat exchanger.

8. The natural gas system of claim 1 , wherein the supply line is connected downstream of a first portion of the heat exchanger and upstream of a second portion of the heat exchanger.

9. A dual fuel engine system comprising:
a tank configured to store natural gas;
a feed line structured to receive a flow of natural gas from the tank and to divide the flow of natural gas into a first stream of natural gas and a second stream of natural gas;
a heat exchanger in fluid communication with the tank by way of the feed line, the heat exchanger configured to receive the first stream of natural gas from the feed line and to exchange heat with the first stream of natural gas passing therethrough;
a temperature regulating assembly positioned downstream of the heat exchanger with respect to the first stream of natural gas, the temperature regulating assembly comprising:
a conduit having an inlet and an outlet;
a supply line in fluid communication with the feed line upstream of the heat exchanger and in selective fluid communication with the conduit via a port downstream of the heat exchanger, the supply line configured to receive the second stream of natural gas from the feed line and to introduce the second stream of natural gas into the conduit, wherein a temperature of the second stream is lower than a temperature of the first stream; and
a temperature sensing assembly provided within the conduit, the temperature sensing assembling configured to control an opening of the port based on a temperature of the natural gas within the conduit; and

an intake manifold in fluid communication with the outlet of the conduit.

10. The dual fuel engine system of claim 9 further comprising a mixing element positioned upstream of the inlet.

11. The dual fuel engine system of claim 9 further comprising a cover element associated with the port, wherein the opening of the port is based on a movement of the cover element.

12. The dual fuel engine system of claim 9 , wherein the temperature sensing assembly comprises a sensing element configured to any one of expand and contract based on the temperature of the natural gas within the conduit.

13. The dual fuel engine system of claim 9 , wherein the supply line is coupled upstream of the heat exchanger.

14. The dual fuel engine system of claim 9 , wherein the supply line is connected upstream of a first portion of the heat exchanger and downstream of a second portion of the heat exchanger.

15. A method for regulating an introduction temperature of natural gas into an intake manifold of a dual fuel engine, the method comprising:
producing a first stream of natural gas and a second stream of natural gas from a natural gas supply;
introducing the first stream of natural gas into a heat exchanger;
introducing the first stream of natural gas after having been heated to an increased temperature by way of the heat exchanger into a conduit structured to fluidly connect to an intake manifold in a dual fuel engine; and
selectively introducing the second stream of natural gas into the conduit based on a temperature of natural gas within the conduit,
wherein the second stream of natural gas flows in parallel with the first stream of natural gas between the natural gas supply and the conduit and is not heated to the increased temperature by way of the heat exchanger, such that a temperature of the second stream of natural gas upon introduction into the conduit is lower than a temperature of the first stream of natural gas upon introduction into the conduit.

16. The method of claim 15 , wherein selectively introducing the second stream of natural gas further comprises:
actuating a cover element associated with a port of a supply line based on the temperature of the natural gas within the conduit; and
opening the port of the supply line based on the actuation.

17. The method of claim 16 further comprising:
any one of expanding and contracting a sensing element provided within the conduit based on the temperature of the natural gas within the conduit.

18. The method of claim 15 further comprising:
decreasing the temperature of the natural gas within the conduit based on the introduction.

19. The method of claim 15 further comprising:
introducing the natural gas into an intake manifold of an engine.

20. The method of claim 15 further comprising:
introducing turbulence in the heated first stream of the natural gas entering the conduit.

Assignees

• Caterpillar Inc

Inventors

• Schaller David F
• Voelker James M

Classifications

• F02D19/0605

  to adjust the fuel pressure or temperature · CPC title

• F02D19/0647

  the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME] · CPC title

• F02D41/0027 Primary

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• F02D2200/0606

  Fuel temperature · CPC title

• F02D19/0673

  Valves; Pressure or flow regulators; Mixers · CPC title