US3577731A

US3577731A - Engine ignition system

Info

Publication number: US3577731A
Application number: US846833A
Authority: US
Inventors: Raymond J Bruchez Jr
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1969-08-01
Filing date: 1969-08-01
Publication date: 1971-05-04
Anticipated expiration: 1988-05-04

Abstract

An ignition device for a turbine engine wherein said device has means for compressing air to a specified temperature and then directing said air into a combustion chamber. A predetermined metered amount of fuel in injected into the hot air so that auto ignition temperature is reached within the passageways of a catalytic restrictor-emitter. The flame started by the restrictor-emitter is held on its surface as a flame holder while the flame front projects into the combustion chamber to ignite a fuel/air mixture.

Description

United States Patent [72] Inventor Raymond J. Bruchez, Jr.

Lake Park, Fla. [21 Appl. No. 846,833 [22] Filed Aug. 1, 1969 [45] Patented May 4, l 71 [73] Assignee United A rcraft Corporation East Hartford, Conn.

[54] ENGINE IGNITION SYSTEM 11 Claims, 2 Drawing Figs. [52] US. Cl 60/39.82, 123/144, 431/268 [51] Int. Cl F021: 7/26 [50] Field of Search 60/3982, 39.82(P), 39.06, 39.82(C); 123/144; 431/268(Inquired) [56] References Cited UNITED STATES PATENTS 799,856 9/1905 Lemale 60/3982 2,760,340 8/1956 Seglem 60/3982 2,920,445 1/1960 Bailey 60/3982 2,929,211 3/1960 Meyer 60/3982 3,355,885 12/1967 Toone 60/3982 FOREIGN PATENTS 612,060 11/1948 GreatBritain 60/3982 Primary Examiner-Douglas Hart Att0rneyJack N. McCarthy rlNSULATlON I, -f5:'.- 241 a 57 /z 2/ i Z L5 I L5 44 5/; 57 42 54 Ei{8 VR id E a w 54 t 6 M M L-- START 4 TSFIQGLET f PATENTED MAY 4 |97| COM PR EssoR comausnom SECTION EXHAUST SECTION SECTION INSULATION INVENTOR. RAYMOND J. BRUCHEZJr ENGINE IGNITION SYSTEM BACKGROUND OF THE INVENTION In the ignition art for turbine engines two types appear to be the most closely related to the subject device. One is the type of system that uses a pyrophoric fuel "and the second is a system in which a fuel is injected around a glow plug. However, subject ignition device differs basically therefrom. A pyrophoric ignition system is shown in U.S. Pat. No. 2,959,007 and an ignition system using a glow plug is shown in U.S. Pat. No. 3,403,511.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide an igniter utilizing jet engine fuel and hydraulic pressure to produce positive sustained directional emission. In accordance with this invention, a hydraulic actuator is connected to a double-acting pump whereby air is raised to a temperature adequate to accomplish auto ignition with a catalyst. This invention also includes a restrictor-emitter which includes stacked screen-type layers of platinum-type material which acts as a catalyst with the heated air and predetermined metered fuel which passes therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a gas turbine engine showing the location of an igniter as disclosed in this application with respect to a combustion chamber.

FIG. 2 is an enlarged sectional view showing the igniter in detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a gas turbine power plant is shown indicated generally by I; the power plant having a compressor section 2, a combustion section 4, a turbine section 6, and an exhaust section 8. The combustion section 4 is comprised having annular combustion chamber, or burner, positioned between the downstream end of the compressor section and the entrance to the turbine section. A power plant such as shown in FIG. 1 is disclosed more in detail in U.S. Pat. No. 3,980,176.

Air is directed to the burners 10 directly from the compressor section and fuel is injected into the chamber by fuel nozzles, not shown. Conventional gas turbine controls are used to obtain the desired fuel-air mixture. To ignite the fuel-air mixture, an ignition device 12 is provided. This ignition device 12 includes (1) a main igniter 14, (2) a control means 16, and (3) an injector 18.

The main igniter 14 includes two axially aligned

cylinders

20 and 22. These cylinders are connected at their adjacent ends by a rigid interconnecting member 24. Each cylinder, 20 and 22, has a piston member, 26 and 28, slideably mounted therein, respectively, for axial movement. A rod 30 is connected to the face of each of the piston members facing each other and extends through the member 24. This connection coordinates the movement of the two piston members. Seal means 32 extends around the 'rod 30 adjacent cylinder 20 and seal means 34 extends around the rod 30 adjacent cylinder 22.

Cylinder 20 has an opening 42 at its end adjacent to cylinder 22 and an opening 44 at is opposite end. Valve mechanism 46 cooperates with opening 42 to act as a check valve to only allow the fluid, air as shown, to flow from the cylinder 20. Valve mechanism 48 cooperates with opening 44 to act as a check valve to only allow the fluid to flow from the cylinder 20. A pressure reservoir 50 is positioned adjacent said cylinder and is connected to the

openings

42 and 44. An air admission valve 52 is located on the cylinder 20 at the center thereof. This valve is a one-way valve and only permits air to enter the cylinder 20. Conduit means 54 extends from the reservoir 50 and passes through the casing of the engine 1 and through the wall of the combustion chamber 10 to the interior thereof. A valve seat 56 is formed in conduit 54 and a valve member 58 is moveable into and out of cooperation with the valve seat 56 to start or stop the flow from the reservoir 50 through the conduit means 54.

A catalytic restrictor-emitter 60, part of the injector I8, is positioned at the exit of said conduit means as it enters the combustion chamber. Valve member 58 is controlled by an actuating rod 62 which extends into the control means 16. An ignition fuel injector 64, part of the injector 18, is located in said conduit means 54 to direct a fuel into the restrictoremitter 60. A tube 66 interconnects the injector 64 with the control means 16. The control means 16 opens valve member 58 when desired and sends a predetermined metered amount of an ignition fuel through tube 66 to the injector 64 at the same time to have proper ignition. This action occurs when the desired temperature or pressure in the reservoir 50 is sensed by sensing device 57 and a signal is sent to the control 16. The volume, V of the conduit means 54 between the valve 58 and restrictor-emitter 60 is minimized in relation to the volume, V of the reservoir 50, where, for example V could be one-tenth of V Control means 16 includes a source of fluid at actuating pressure and a reservoir of fluid at low pressure. A control lever 40 is mechanically connected to the control means 16 so that in its start position, as shown by solid lines in FIG. 2, with valve member 58 in the closed position the control means 16 will direct fluid from the high-pressure source to a first side of said piston member 28 while connecting the other side to the reservoir at low pressure. When the piston member 28 reaches the end of cylinder 22 the control means 16 redirects the high pressure from the source to the other side of the piston member 28 and connects the first side to the reservoir thereby reversing direction. This action is repeated until the temperature of the air in the pressure reservoir 50 is enough to start ignition.

This type of control is not new where a valve alternately connects a high-pressure source from one end of a cylinder to its other, while connecting the opposite end to a drain or a reservoir. Means for detecting when the piston member 28 has reached either end of the cylinder can be a mechanical device actuated by the member such as shown at 37 and 39. Conduits 36 and 38 interconnect the control means 16 to the opposite ends of the cylinder 22 for the flow of fluid just referred to.

In operation when the control lever 40 is moved to the start position the control means 16 supplies fluid to the cylinder 22 to move the piston 28 therein from one end to the other until the piston 26 and cylinder 20 increases temperature in a reservoir 50 to a value which is adequate to accomplish auto ignition of a fuel in the restrictor-emitter 60. The piston 26 draws air in through the valve 52 and, since the valve 58 is being held in its closed position, forces the air through one check valve mechanism 46 and then the other check valve mechanism 48 to increase the pressure and temperature in the reservoir 50.

When the desired temperature is reached in the reservoir 50, the temperature sensor 57 sends a signal to the control means 16 which then opens valve 58 and discharges a predetermined metered fuel charge into the hot air as it enters the catalytic restrictor-emitter. The restrictor-emitter is positioned between the reservoir and the combustion chamber such that auto ignition temperature is reached within the passageways of the restrictor-emitter and the surface of the emitter facing the combustion chamber acts as a holder for the flame front which emits into the combustion chamber to ignite the fuel-air mixture therein.

When ignition occurs, valve 58 has closed and the predetermined metered fuel charge has been used. The control means 16 is reset to be reoperated for another ignition attempt, if necessary.

I claim:

1. In combination, an engine, said engine having a combustion chamber therein and an igniter, said igniter having means for compressing air to an elevated temperature, container means for holding said compressed air, first conduit means connecting said container means for holding said compressed air to said combustion chamber, valved means for controlling the flow of compressed air from said container means to said first conduit means, a catalytic'element in said first conduit means downstream of said valved means, a fuel supply, a second conduit means connecting said fuel supply to said first conduit means for injecting fuel into said first conduit means upstream of said catalytic element, control means for releasing compressed air from said container means into said first conduit means through said valved means and for releasing fuel from said fuel supply into said first conduit means through said second conduit means.

2. A combination as set forth in claim 1 wherein said means for releasing fuel from said supply releases a metered charge of fuel.

3. A combination as set forth in claim 1 wherein said means for compressing air comprises two cylinder and piston units, one cylinder and piston unit pumping said air into said container holding means for said compressed air, the second cylinder and piston unit being actuated by fluid pressure directly on one side of piston and then on the other after it has moved a predetermined distance.

4. A combination as set forth in claim 1 wherein a sensing device is positioned to sense a parameter of compressed air, said sensing device being connected to said control means so that a signal is sent to said control means when said predetermined parameter has been reached and said control means then actuates said valved means releasing said compressed air to flow into said first conduit means and pass through said catalytic element.

5. A combination as set forth in claim 3 wherein said one cylinder and piston unit has an opening in each end which is connected to said container holding means for said compressed air, a check valve is connected with each opening so that air is pumped from said cylinder and piston unit into said container means for holding said compressed air and held there.

6. A combination as set forth in claim 1 wherein said means for compressing air comprises two cylinder and piston units, one cylinder and piston unit pumping said air into said container means for holding said compressed air, the second cylinder and piston unit being actuated by fluid pressure directly on one side of piston and then on the other after it has vmoved a predetermined distance, the one cylinder and piston unit has an opening in each end which is connected to said container means for holding said compressed air, a check valve is connected with each opening so that air is pumped from said cylinder and piston unit into said container means for holding said compressed air and held there.

7. A combination as set forth in claim 1 wherein said control means is responsive to a sensing device which releasesthe compressed air when it has reached a predetermined temperature.

8. A combination as set forth in claim 1 wherein said first conduit means is connected to said container means while its other end projects into said combustion chamber, said valved means being located where said first conduit means is connected to said container means.

9. A combination as set forth in claim 1 wherein an injector is located in said first conduit means and connected to the second conduit means, said fuel being released through said injector.

10. A combination as set forth in claim 1 wherein said first conduit means forms a specific volume V between said valved means and said catalytic element, and said container means forms a specific volume V these volumes having a relationship of V,,=l/l0 V

Claims

1. In combination, an engine, said engine having a combustion chamber therein and an igniter, said igniter having means for compressing air to an elevated temperature, container means for holding said compressed air, first conduit means connecting said container means for holding said compressed air to said combustion chamber, valved means for controlling the flow of compressed air from said container means to said first conduit means, a catalytic element in said first conduit means downstream of said valved means, a fuel supply, a second conduit means connecting said fuel supply to said first conduit means for injecting fuel into said first conduit means upstream of said catalytic element, control means for releasing compressed air from said container means into said first conduit means through said valved means and for releasing fuel from said fuel supply into said first conduit means through said second conduit means.

6. A combination as set forth in claim 1 wherein said means for compressing air comprises two cylinder and piston units, one cylinder and piston unit pumping said air into said container means for holding said compressed air, the second cylinder and piston unit being actuated by fluid pressure directly on one side of piston and then on the other after it has moved a predetermined distance, the one cylinder and piston unit has an opening in each end which is connected to said container means for holding said compressed air, a check valve is connected with each opening so that air is pumped from said cylinder and piston unit into said container means for holding said compressed air and held there.

7. A combination as set forth in claim 1 wherein said control means is responsive to a sensing device which releases the compressed air when it has reached a predetermined temperature.

10. A combination as set forth in claim 1 wherein said first conduit means forms a specific volume VE between said valved means and said catalytic element, and said container means forms a specific volume VR, these volumes having a relationship of VE 1/10 VR.

11. A combination as set forth in claim 1 wherein said catalytic element is a restrictor-emitter which will accomplish auto ignition of a fuel therein with a flow of air passing therethrough which is at an elevated temperature.