US4041697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil cooling system for a gas turbine engine
Assignee: National Aeronautics and Space Administration
•
Filing: 1975-07-17
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Granted: 1977-08-16
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Expires: 1995-07-17
Abstract
Abstract A gas turbine engine fuel delivery and control system is provided with means to recirculate all fuel in excess of fuel control requirements back to the aircraft fuel tank, thereby increasing the fuel pump heat sink and decreasing the pump temperature rise without the addition of valving other than that normally employed. A fuel/oil heat exchanger and associated circuitry is provided to maintain the hot engine oil in heat exchange relationship with the cool engine fuel. Where anti-icing of the fuel filter is required, means are provided to maintain the fuel temperature entering the filter at or above a minimum level to prevent freezing thereof. In one embodiment, a divider valve is provided to take all excess fuel from either upstream or downstream of the fuel filter and route it back to the tanks, the ratio of upstream to downstream extraction being a function of fuel pump discharge pressure. In addition, fluid circuitry is provided to route hot engine oil through a plurality of heat exchangers disposed within the system to provide for selective cooling of the oil.
Inventors
- 👤 George A. Coffinberry
- 👤 Howard B. Kast
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:03
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/12; F02C7/14; F02C7/22; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2514; Y10T137/2521; Y10T137/2524
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
144 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow to the engine; a first heat exchanger for receiving all of the metered fuel and further communicating with the gas turbine engine for receipt of hot engine oil therefrom, wherein the hot engine oil is maintained in heat exchange relation with the fuel and then returned to the engine at a cooler temperature; and means for reducing the fuel temperature to the inlet of the first heat exchanger by returning all fuel in excess of engine requirements back to the fuel reservoir.
Claim 2
Dependent Claim
144 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow to the engine; a first heat exchanger for receiving all of the metered fuel and further communicating with the gas turbine engine for receipt of hot engine oil therefrom, wherein the hot engine oil is maintained in heat exchange relation with the fuel and then returned to the engine at a cooler temperature; and means for reducing the fuel temperature to the inlet of the first heat exchanger by returning all fuel in excess of engine requirements back to the fuel reservoir.
Claim 3
Dependent Claim
44 words
The fuel delivery and control system of claim 1 wherein the fuel temperature reducing means includes a bypass valve for returning the excess pressurized fuel to the fuel reservoir whenever the flow upstream of the metering means exceeds the flow required by the engine.
Claim 4
Dependent Claim
22 words
The fuel delivery and control system of claim 2 further comprising combustor means downstream of the fuel control and first heat exchanger.
Claim 5
Dependent Claim
49 words
The fuel delivery and control system of claim 2 further comprising a second heat exchanger downstream of the pump means such that all of the fuel discharged from the pump means passes through the second heat exchanger and all of the metered fuel passes through the first heat exchanger.
Claim 6
Dependent Claim
30 words
The fuel delivery and control system of claim 4 wherein the hot engine oil is adapted to pass serially through the second heat exchanger and then the first heat exchanger.
Claim 7
Dependent Claim
26 words
The fuel delivery and control system of claim 2 further comprising a second heat exchanger for receiving the pressurized fuel in excess of the metered fuel.
Claim 8
Dependent Claim
30 words
The fuel delivery and control system of claim 6 where the hot engine oil is adapted to pass serially through the second heat exchanger and then the first heat exchanger.
Claim 9
Dependent Claim
23 words
The fuel delivery and control means of claim 2 further comprising filter means for filtering matter from the fuel entering the metering means.
Claim 10
Dependent Claim
28 words
The fuel delivery and control system of claim 4 further comprising fuel filter means disposed in serial flow communication between the second heat exchanger and the metering means.
Claim 11
Dependent Claim
217 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means for drawing fuel from the reservoir and pressurizing means; a first heat exchanger in downstream fuel flow communication with said pump means for receiving at least a portion of the pressurized fuel therefrom and further communicating with a source of hot fluid which is maintained in heat exchange relationship with the fuel; a fuel control in downstream fuel flow communication with said first heat exchanger for receiving at least a portion of the pressurized fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow of the engine; means for filtering particulate matter from that portion of the pressurized fuel passing through said first heat exchanger; by pass valve means responsive to the engine fuel requirements for returning pressurized fuel in excess of engine requirements back to the fuel reservoir whenever the fuel flow upstream of the metering means exceeds the engine requirements; and divider valve means for receiving the excess pressurized fuel from two locations, one location being upstream of said first heat exchanger and filter means, and the other being downstream of said first heat exchanger and filter means, and for discharging the fuel through the bypass valve means.
Claim 12
Dependent Claim
217 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means for drawing fuel from the reservoir and pressurizing means; a first heat exchanger in downstream fuel flow communication with said pump means for receiving at least a portion of the pressurized fuel therefrom and further communicating with a source of hot fluid which is maintained in heat exchange relationship with the fuel; a fuel control in downstream fuel flow communication with said first heat exchanger for receiving at least a portion of the pressurized fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow of the engine; means for filtering particulate matter from that portion of the pressurized fuel passing through said first heat exchanger; by pass valve means responsive to the engine fuel requirements for returning pressurized fuel in excess of engine requirements back to the fuel reservoir whenever the fuel flow upstream of the metering means exceeds the engine requirements; and divider valve means for receiving the excess pressurized fuel from two locations, one location being upstream of said first heat exchanger and filter means, and the other being downstream of said first heat exchanger and filter means, and for discharging the fuel through the bypass valve means.
Claim 13
Dependent Claim
88 words
The fuel delivery and control system of claim 10 wherein th bypass valve means is so constructed that the ratio of fuel received from the one upstream location to that passing through the bypass valve means is scheduled such that the amount of heat transferred to the fuel reservoir is less than or equal to the amount of heat that can be dissipated by the fuel reservoir and the temperature of the fuel entering the filter means is maintained above a minimum temperature to eliminate ice formation therein.
Claim 14
Dependent Claim
55 words
The fuel delivery and control system of claim 11 wherein the bypass valve means is further characterized in its construction such that the fuel flow from the other downstream location is scheduled to be substantially zero at the engine take-off and ground idle power settings and to be a positive value at power settings therebetween.
Claim 15
Dependent Claim
144 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom and including metering means for scheduling the rate of fuel flow to the engine; heat exchange means for receiving at least a portion of the pressurized fuel and further communicating with the gas turbine engine for receipt of hot engine oil therefrom, wherein the hot engine oil is maintained in heat exchange relation with the fuel and then returned to the engine at a cooler temperature; means for filtering particulate matter from the fuel entering the metering means; and means for maintaining the temperature of the fuel entering the filter means above a minimum level.
Claim 16
Dependent Claim
144 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom and including metering means for scheduling the rate of fuel flow to the engine; heat exchange means for receiving at least a portion of the pressurized fuel and further communicating with the gas turbine engine for receipt of hot engine oil therefrom, wherein the hot engine oil is maintained in heat exchange relation with the fuel and then returned to the engine at a cooler temperature; means for filtering particulate matter from the fuel entering the metering means; and means for maintaining the temperature of the fuel entering the filter means above a minimum level.
Claim 17
Dependent Claim
105 words
The fuel delivery and control system of claim 13 wherein the fuel temperature maintaining means includes a bypass valve for returning all fuel in excess of engine requirements from the filter discharge to a thermal control means whenever the fuel flow upstream of the metering means exceeds the requirements of the engine; and wherein the discharge of the thermal control means is in fuel flow communication with the fuel reservoir and the pump means inlet, the thermal control means scheduling a decreasing rate of fuel to the fuel reservoir as a function of decreasing fuel temperature, the remainder being routed to the pump means inlet.
Claim 18
Dependent Claim
63 words
The fuel deivery and control system of claim 14 wherein the heat exchange means includes a first heat exchanger downstream of the pump means and a second heat exchanger downstream of the fuel control such that all of the fuel discharged from the pump means passes through the first heat exchanger and all of the metered fuel passes through the second heat exchanger.
Claim 19
Dependent Claim
35 words
The fuel delivery and control system of claim 14 wherein the heat exchange means includes a first heat exchanger for receiving the excess pressurized fuel and a second heat exchanger for receiving the metered fuel.
Claim 20
Dependent Claim
32 words
The fuel delivery and control system of claim 10 further comprising a second heat exchanger wherein the excess pressurized fuel and a liquid to be cooled are maintained in heat exchange relationship.
Claim 21
Dependent Claim
88 words
A fuel delivery system comprising: a first fuel-oil heat exchanger; a second fuel-oil heat exchanger in downstream fuel flow communication with said first heat exchanger; a first oil cooling circuit comprising, in sequential oil flow communication, an oil supply, a first oil-lubricated system, said second heat exchanger, and means for returning the oil to said oil supply; and a second oil cooling circuit comprising, in sequential oil flow communication, said oil supply, said first heat exchanger, a second oil-lubricated system, said second heat exchanger and said return means.
Claim 22
Dependent Claim
88 words
A fuel delivery system comprising: a first fuel-oil heat exchanger; a second fuel-oil heat exchanger in downstream fuel flow communication with said first heat exchanger; a first oil cooling circuit comprising, in sequential oil flow communication, an oil supply, a first oil-lubricated system, said second heat exchanger, and means for returning the oil to said oil supply; and a second oil cooling circuit comprising, in sequential oil flow communication, said oil supply, said first heat exchanger, a second oil-lubricated system, said second heat exchanger and said return means.
Claim 23
Dependent Claim
84 words
A fuel delivery system comprising: a first fuel-oil heat exchanger; a second fuel-oil heat exchanger in downstream fuel flow communication with said first heat exchanger; a first oil cooling circuit comprising, in sequential oil flow communication, an oil supply, said first heat exchanger, said first oil-lubricated system and means for returning the oil to said oil supply; and a second oil cooling circuit comprising, in sequential oil flow communication, said oil supply, a second oil-lubricated system, said second heat exchanger and said return means.
Claim 24
Dependent Claim
84 words
A fuel delivery system comprising: a first fuel-oil heat exchanger; a second fuel-oil heat exchanger in downstream fuel flow communication with said first heat exchanger; a first oil cooling circuit comprising, in sequential oil flow communication, an oil supply, said first heat exchanger, said first oil-lubricated system and means for returning the oil to said oil supply; and a second oil cooling circuit comprising, in sequential oil flow communication, said oil supply, a second oil-lubricated system, said second heat exchanger and said return means.
Claim 25
Dependent Claim
91 words
The fuel delivery and control system of claim 2 further comprising a second heat exchanger in serial fuel flow relationship with said first heat exchanger and two oil cooling circuits, the first circuit comprising, in serial oil flow relationship, an oil supply, said first heat exchanger, a first lubricated system, and means for returning oil to said oil supply, and said second circuit comprising, in serial oil flow relationship, said oil supply, said second heat exchanger, a second oil lubricated system and said means for returning oil to said oil supply.
Claim 26
Dependent Claim
110 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow to the engine; a heat exchanger for receiving all of the metered fuel and further communicating with a source of hot fluid which is maintained in heat exchange relation with the fuel; and means for returning all fuel in excess of engine requirements back to the fuel reservoir.
Claim 27
Dependent Claim
110 words
A fuel delivery and control system for use with a gas turbine engine and a fuel reservoir, said system comprising: pump means communicating with the fuel reservoir for drawing fuel therefrom and pressurizing same; a fuel control in downstream flow communication with the pump means for receiving fuel therefrom, said fuel control including metering means for scheduling the rate of fuel flow to the engine; a heat exchanger for receiving all of the metered fuel and further communicating with a source of hot fluid which is maintained in heat exchange relation with the fuel; and means for returning all fuel in excess of engine requirements back to the fuel reservoir.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |