Tube assembly

Patent metadata

Field	Value
Publication number	US-10480868-B2
Application number	US-201815905120-A
Country	US
Kind code	B2
Filing date	Feb 26, 2018
Priority date	Jul 3, 2014
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A tube assembly that may be for a fuel nozzle of a fuel system of a gas turbine engine may have a first tube defining a first flowpath along a centerline, a second tube generally spaced radially outward from the first tube with a first void located between and defined by the first and second tubes, and a support structure located in the first void and extending between the first and second tubes. The support structure is constructed and arranged to minimize or eliminate thermal conduction between the tubes. The entire assembly may be additive manufactured as one unitary piece. One example of a method of operation may include designed-for breakage of the structural support due to thermal stresses thereby further minimizing thermal conduction between tubes.

First claim

What is claimed is:

1. A method of operating a fuel system of a gas turbine engine comprising the steps of:
flowing a first fluid through a first flowpath defined by a first tube;
exposing a second tube surrounding and spaced radially outward from the first tube to a first thermal gradient; and
breaking a first sacrificial support structure located between the first and second tubes via thermal stress induced by the first thermal gradient.

2. The method set forth in claim 1 comprising the further steps of:
flowing a second fluid through an annular second flowpath defined between the second tube and a third tube that is spaced from the second tube;
exposing the third tube to a second thermal gradient; and
breaking a second sacrificial support structure located between the second and third tubes via thermal stress induced by the second thermal gradient.

3. The method set forth in claim 1 , wherein the second tube is spaced radially outward from the first tube by a radial distance, and wherein the first sacrificial support structure has a length greater than the radial distance.

4. The method set forth in claim 3 , wherein the first flowpath is defined along a centerline, and wherein the first support structure lies in a plane that is normal to the centerline.

5. The method set forth in claim 1 , wherein the first flowpath is defined along a centerline, and wherein the first support structure lies in a plane that is normal to the centerline.

6. The method set forth in claim 1 , wherein the first sacrificial support structure has a thickness within a range of 0.004 to 0.008 inches.

7. The method set forth in claim 1 , wherein the first tube and the second tube define a void between the first tube and the second tube, and wherein the void is under a negative atmospheric pressure.

8. The method set forth in claim 1 , wherein the first support structure is one of a plurality of first support structures spaced circumferentially from one-another.

Assignees

• United Technologies Corp

Inventors

• Ott Joe
• Rup Jr John J
• Funk Stanley J
• Moura Dennis M
• Kironn Lexia
• Coffey Roger O

Classifications

• F23D2211/00

  Thermal dilatation prevention or compensation · CPC title

• F28F1/00 Primary

  Tubular elements; Assemblies of tubular elements (specially adapted for movement F28F5/00) · CPC title

• F16L59/14

  Arrangements for the insulation of pipes or pipe systems (F16L59/02 - F16L59/12 take precedence) · CPC title

• F16L9/18

  Double-walled pipes; Multi-channel pipes or pipe assemblies · CPC title

• F23R3/283 Primary

  Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances · CPC title