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US-12618410-B2 - Fuel system with electric generator integrated boost stage

US12618410B2US 12618410 B2US12618410 B2US 12618410B2US-12618410-B2

Abstract

An aircraft fuel system includes a first integrated boost stage having a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line, at least one generator collocated with and operatively connected to the boost pump for driving the boost pump, and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator. The fuel system further includes a gearbox operatively connected to the at least one generator, and a main stage downstream of the boost stage and operatively connected to the gearbox. The main stage includes a main pump configured to receive the fuel flow from the boost pump along a main supply line, and a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow.

Inventors

  • Naison E. Mastrocola
  • Ryan P. Susca

Assignees

  • HAMILTON SUNDSTRAND CORPORATION

Dates

Publication Date
20260505
Application Date
20240322

Claims (20)

  1. 1 . An aircraft fuel system comprising: a first integrated boost stage comprising: a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line; at least one generator collocated with and operatively connected to the boost pump for driving the boost pump; and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator; a gearbox operatively connected to the at least one generator; and a main stage downstream of the boost stage and operatively connected to the gearbox, the main stage comprising a main pump configured to receive the fuel flow from the boost pump along a main supply line.
  2. 2 . The fuel system of claim 1 and further comprising: a second integrated boost stage comprising: a boost pump configured to receive a fuel flow from a fuel tank via the boost supply line; at least one generator collocated with and operatively connected to the boost pump for driving the boost pump; and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator.
  3. 3 . The fuel system of claim 2 , wherein the boost pump of each of the first and second integrated boost stages is a centrifugal pump.
  4. 4 . The fuel system of claim 2 , wherein the at least one generator of each of the first and second integrated boost stages is a direct drive generator.
  5. 5 . The fuel system of claim 2 , wherein the main pump is a positive displacement pump.
  6. 6 . The fuel system of claim 2 and further comprising: a boost outlet line fluidly coupling each boost pump of the first and second integrated boost stages to the main supply line; and a check valve disposed along the boost outlet line.
  7. 7 . The fuel system of claim 2 and further comprising: a generator outlet line fluidly coupling the at least one generator of each of the first and second integrated boost stages to the boost supply line to return a circulated amount of the fuel flow through the at least one generator to the boost supply line.
  8. 8 . The fuel system of claim 2 and further comprising: an orifice disposed along the tap of each of the first and second integrated boost stages.
  9. 9 . The fuel system of claim 2 and further comprising: a heat exchanger upstream of the main stage.
  10. 10 . The fuel system of claim 2 , wherein the main stage further comprises: a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow.
  11. 11 . The fuel system of claim 2 , wherein the main stage further comprises: a metering valve downstream of the main pump.
  12. 12 . An aircraft fuel system comprising: an integrated boost stage comprising: a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line; at least one permanent magnet machine collocated with and operatively connected to the boost pump for driving the boost pump; and a tap fluidly connecting the boost pump and the at least one permanent magnet machine for selectively delivering an amount of the fuel flow to the at least one permanent magnet machine; a gearbox operatively connected to the at least one permanent magnet machine; and a main stage downstream of the boost stage and operatively connected to the gearbox, the main stage comprising a main pump configured to receive the fuel flow from the boost pump along a main supply line.
  13. 13 . The fuel system of claim 12 , wherein the at least one permanent magnet machine comprises two permanent magnet machines.
  14. 14 . The fuel system of claim 13 , wherein each of the permanent magnet machines is one of a permanent magnet alternator and a permanent magnet generator.
  15. 15 . The fuel system of claim 13 and further comprising: a boost outlet line fluidly coupling the boost pump to the main supply line.
  16. 16 . The fuel system of claim 13 and further comprising: a permanent magnet machine outlet line fluidly coupling each permanent magnet machine to the boost supply line to return a circulated amount of the fuel flow through each permanent magnet machine to the boost supply line.
  17. 17 . The fuel system of claim 13 and further comprising: an orifice disposed along the tap.
  18. 18 . The fuel system of claim 13 and further comprising: a heat exchanger upstream of the main stage.
  19. 19 . The fuel system of claim 13 , wherein the main stage further comprises: a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow.
  20. 20 . The fuel system of claim 13 , wherein the main stage further comprises: a metering valve downstream of the main pump.

Description

BACKGROUND The present disclosure relates generally to a fuel system, and more particularly to an aircraft fuel system. Aircraft fuel systems can include multiple pumps, including one or more primary or main/motive pumps and one or more boost pumps for increasing the pressure of fuel delivered to the primary pumps. The boost stage of such fuel systems can benefit from a second accessory drive pad to run the boost pumps at a different speed from the main pumps, as the ideal operating speeds of each type of pump can vary by several thousand RPMs in some examples. However, the cost and weight of an additional gear centerline and housing detracts from the benefits. As such, alternative means for operating boost pumps and main pumps at their optimal respective speeds are desirable. SUMMARY An aircraft fuel system includes a first integrated boost stage having a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line, at least one generator collocated with and operatively connected to the boost pump for driving the boost pump, and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator. The fuel system further includes a gearbox operatively connected to the at least one generator, and a main stage downstream of the boost stage and operatively connected to the gearbox. The main stage includes a main pump configured to receive the fuel flow from the boost pump along a main supply line, and a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow. An aircraft fuel system includes at least one integrated boost stage having a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line, at least one permanent magnet machine collocated with and operatively connected to the boost pump for driving the boost pump, and a tap fluidly connecting the boost pump and the at least one permanent magnet machine for selectively delivering an amount of the fuel flow to the at least one permanent magnet machine. The fuel system further includes a gearbox operatively connected to the at least one permanent magnet machine, and a main stage downstream of the boost stage and operatively connected to the gearbox. The main stage includes a main pump configured to receive the fuel flow from the boost pump along a main supply line, and a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of an aircraft fuel system with integrated boost stages according to a first embodiment. FIG. 2 is a schematic illustration of an aircraft fuel system with an integrated boost stage according to a second embodiment. While the above-identified figures set forth embodiments of the present invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features, steps and/or components not specifically shown in the drawings. DETAILED DESCRIPTION This disclosure presents fuel systems with integrated boost stages. More specifically, one or more boost pumps can be collocated with the engine generators to operate independently of the main fuel pump and further to provide a cooling/lubricating fuel flow to the generators. FIG. 1 is a schematic illustration of a portion of fuel system 10 for an aircraft. As shown in FIG. 1, fuel system 10 can include at least one fuel tank 12 which can be located within a fuselage or wing of aircraft 14, and integrated boost stages 16, each including a boost pump 18 and generator 20. Boost pumps 18 can be centrifugal pumps, and generators 20 can be integrated direct drive generators in an exemplary embodiment. System 10 can further include gearbox 22, heat exchanger 24, and main stage 26 including main pump 28 and fuel filter 30 for providing filtered fuel to, component(s) 32 of engine 34 which can be, in one example, combustor nozzles. Main pump 28 can be a positive displacement pump, such as a gear pump, in an exemplary embodiment, while heat exchanger 24 can be a fuel engine oil cooler. As schematically represented in FIG. 1, integrated boost stages 16, gearbox 22, heat exchanger 24, and main stage 26 can be physically and mechanically coupled to engine 34. In operation of fuel system 10, fuel can be urged/drawn from fuel tank 12 by boost pumps 18 along boost supply line 36 which can be branched to provide fuel to n number of boost pumps 18 of m number of boost stages 16, although two are depicted in FIG. 1. Each boo