Variable displacement pump (VDP) systems with dual dry out pumps

Patent metadata

Field	Value
Publication number	US-12366206-B2
Application number	US-202318244390-A
Country	US
Kind code	B2
Filing date	Sep 11, 2023
Priority date	Sep 11, 2023
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

A fuel system includes a main fuel pump sub-system (MFP) with an inlet for receiving a supply of fuel from an inlet line. The MFP has a main outlet line configured to supply fuel to a main fuel throttle valve assembly (MFTV), a first cross-over outlet line, and a second cross-over outlet line. An augmentor fuel pump sub-system (ABFP) has an inlet connected in fluid communication with the first cross-over outlet line, and an outlet connected in fluid communication with a main augmentor supply line. A variable displacement pump sub-system (VDPP) has an inlet connected in fluid communication with the second cross-over outlet line, a first outlet line configured to connect to supply fuel to the MFTV, and a second outlet line configured to connect to supply fuel to an actuation system.

First claim

What is claimed is:

1. A fuel system comprising:
a main fuel pump sub-system (MFP) with an inlet for receiving a supply of fuel from an inlet line, wherein the MFP has a main outlet line configured to supply fuel to a main fuel throttle valve assembly (MFTV), a first cross-over outlet line, and a second cross-over outlet line;
an augmentor fuel pump sub-system (ABFP) with an inlet connected in fluid communication with the first cross-over outlet line, and an outlet connected in fluid communication with a main augmentor supply line; and
a variable displacement pump sub-system (VDPP) with an inlet connected in fluid communication with the second cross-over outlet line, a first outlet line configured to connect to supply fuel to the MFTV, and a second outlet line configured to connect to supply fuel to an actuation system;
wherein the MFTV includes an MFTV check valve (MFTVCV) connected in fluid communication between the main outlet line and the first outlet line of the VDPP, configured to prevent flow from the main outlet line to the first outlet line of the VDPP, and to allow flow from the first outlet line of the VDPP to the main outlet line; and
wherein the MFTV includes a selector valve (MFTVSV) connected in fluid communication with the first outlet line of the VDPP, with a branch of the main outlet line upstream of the MFTVCV, and with an engine line, wherein the MFTVSV is configured to select between the main outlet line and the first outlet line of the VDPP to supply fuel from the MFTV to the engine line.

2. The system as recited in claim 1 , further comprising the actuation system connected in fluid communication with the second outlet line for hydraulic actuation.

3. The system as recited in claim 1 , further comprising a boost pump configured to pressurize fuel from a source and connected in fluid communication with the inlet of the MFP.

4. The system as recited in claim 1 , wherein the MFP includes a filter in a centrifugal pump feed line, wherein the filter is connected in fluid communication with the inlet of the MFP.

5. The system as recited in claim 4 , wherein the MFP includes an inlet shut off valve (ISOV) in the centrifugal pump feed line downstream of the filter, wherein the ISOV is configured to switch between a first state blocking supply of fuel through the centrifugal pump feed line and a second state supplying fuel through the centrifugal pump feed line.

6. The system as recited in claim 5 , wherein the MFP includes a centrifugal pump connected in fluid communication with the centrifugal pump feed line downstream of the ISOV to be supplied with fuel from the filter with the ISOV in the second state, wherein the centrifugal pump has centrifugal pump outlet in fluid communication with the main outlet line.

7. The system as recited in claim 6 , wherein the MFP includes a stabilizing check valve (SCV) in the main outlet line configured to allow flow from the centrifugal pump through the main outlet line, and to prevent backflow from the main outlet line into the centrifugal pump.

8. The system as recited in claim 7 , wherein the MFP includes a centrifugal pump bypass line connecting in fluid communication from the filter to a point in the main outlet line downstream of the SCV, wherein the centrifugal pump bypass line includes a check valve (MFPCV) configured to prevent backflow from the main outlet line to the filter.

9. The system as recited in claim 8 , further comprising an ejector having a drain inlet connected to in fluid communication with a second branch of the main outlet line that is upstream of the SCV, an ejection inlet connected in fluid communication with a return line from the MFTV, and an outlet connected in fluid communication with a return line configured to be connected to an inlet of a boost pump, wherein the ejector is configured to drain the centrifugal pump using flow from the VDPP through the MFTV.

10. The system as recited in claim 1 , wherein the VDPP includes a variable positive displacement pump, with a pump inlet connected in fluid communication with the second cross-over outlet line, and an outlet connected in fluid communication with a main VDPP pump outlet line connected in fluid communication with the second outlet line.

11. The system as recited in claim 10 , wherein the VDPP includes a check valve (VDPPCV) in the main VDPP pump outlet line, configured to prevent backflow through the main VDPP outlet line into the variable positive displacement pump.

12. The system as recited in claim 11 , wherein the VDPP includes an actuator selector valve (ASV) in the main VDPP pump outlet line downstream of the VDPPCV.

13. The system as recited in claim 12 , wherein the VDPP includes a selector valve (VDPPSV) connected in fluid communication with a branch of the main VDPP pump outlet line that is downstream of the ASV, and in fluid communication with the first outlet line, wherein the VDPPSV is configured to prevent flow from the VDPP to the MFTV in normal operation so the VDPP supplies an actuation system, and to allow flow from the VDPP to the MFTV with the MFP shut off in a low power mode.

14. The system as recited in claim 1 , further comprising the MFTV connected in fluid communication to receive fuel supplied from the VDPP and to output fuel to a gas generator (GG) during engine start-up, and to receive fuel supplied from the MFP and to output fuel to the GG after start-up.

15. The system as recited in claim 14 , further comprising an augmentor fuel control (AFC) connected in fluid communication with a line from the outlet of the ABFP, and with a branch of the second outlet line for providing fuel to an augmentor from the VDPP or MFP as needed.

16. The system as recited in claim 1 , wherein the MFTV includes a regulator connected between the first outlet line of the VDPP an augmentor fuel control line such that the regulator is configured to receive flow from the first outlet line of the VDPP and to output an augmentor fuel control flow.

17. The system as recited in claim 16 , wherein the MFTV includes a thermal recirculation line outlet in fluid communication with the main outlet line configured for supplying a thermal recirculation system.

18. The system as recited in claim 1 , wherein the ABFP includes:
an inlet shut off valve (ISOV) in a centrifugal pump feed line that is in fluid communication with the inlet of the ABFP and the first cross-over outlet line, wherein the ISOV is configured to switch between a first state blocking supply of fuel through the centrifugal pump feed line and a second state supplying fuel through the centrifugal pump feed line;
a centrifugal pump connected in fluid communication with the centrifugal pump feed line downstream of the ISOV to be supplied with fuel from the ISOV in the second state, wherein the centrifugal pump has centrifugal pump outlet in fluid communication with the main augmentor supply line;
a stabilizing check valve (SCV) in the main augmentor supply line configured to allow flow from the centrifugal pump through the main augmentor supply line, and to prevent backflow from the main augmentor supply line into the centrifugal pump;
an ejector having a drain inlet connected in fluid communication with a branch of the main augmentor supply line that is upstream of the SCV, an ejection inlet connected in fluid communication with a return line from the MFTV, and an outlet connected in fluid communication with a return line configured to be connected to an inlet of a boost pump, wherein the ejector is configured to drain the centrifugal pump using flow from the VDPP through the M

Assignees

• Hamilton Sundstrand Corp

Inventors

• Shook Ryan
• Susca Ryan Prescott

Classifications

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title

• F04B23/14

  at least one pump being of the non-positive-displacement type · CPC title

• F02K3/10

  by after-burners (F02K3/105 takes precedence) · CPC title

• F02C7/236 Primary

  Fuel delivery systems comprising two or more pumps · CPC title