Heat exchanger

Patent metadata

Field	Value
Publication number	US-11412642-B2
Application number	US-202016831886-A
Country	US
Kind code	B2
Filing date	Mar 27, 2020
Priority date	Mar 27, 2019
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

A two-start helical heat exchanger comprises a helical baffle extending along a length of the heat exchanger and having first and second surfaces, wherein: the first surface of the baffle is arranged to provide a first helical fluid flow path for a first fluid; and the second surface of the baffle is arranged to provide a second helical fluid flow path for a second fluid, wherein the second fluid flow path is arranged in counter-flow with the first fluid flow path and a casing within which the baffle is mounted. The baffle is arranged such that first and second fluid flow paths are in thermal contact with each other through the baffle, and in thermal contact with the casing. The heat exchanger may be incorporated into a power converter, for example to cool the power converter. The heat exchanger may be used on an aircraft.

First claim

The invention claimed is:

1. A two-start helical heat exchanger comprising:
a helical baffle extending along a length of the heat exchanger and having first and second surfaces,
a cylindrical core encircled by the helical baffle, and
a casing within which the baffle is mounted;
wherein the helical baffle is a hollow thread;
wherein the first surface of the baffle is an interior surface of the baffle and is arranged to provide a first helical fluid flow path within the baffle for a first fluid;
wherein the second surface of the baffle is an exterior surface of the baffle and is arranged to provide a second helical fluid flow path around the baffle for a second fluid, the second surface having a flat portion in direct thermal contact with an interior surface of the casing;
wherein the cylindrical core is hollow at a first end to form a fluid inlet for the first fluid flow path, hollow at a second end to form a fluid outlet for the first fluid flow path, and solid between the two hollow ends; and

wherein the baffle is arranged such that the first and second fluid flow paths are in thermal contact with each other through the baffle, the second fluid flow path is in direct thermal contact with the casing, and the first fluid flow path is in thermal contact with the casing through the baffle.

2. The heat exchanger of claim 1 , wherein the first fluid is a flammable fluid and the second fluid is a non-flammable fluid, and optionally wherein the first fluid is aviation fuel or oil and the second fluid is water.

3. The heat exchanger of claim 1 , wherein a space between the helical baffle and the casing provides the second fluid flow path.

4. The heat exchanger of claim 3 , wherein the casing has a channel therethrough, and wherein the helical baffle is received within the channel such that the channel and the baffle together define the second fluid flow path.

5. The heat exchanger of claim 1 , wherein the helical baffle comprises a single helical thread.

6. The heat exchanger of claim 1 , wherein the casing is a heat spreader.

7. The heat exchanger of claim 1 , wherein the heat exchanger is a heat sink arranged to cool a component outside of the casing, such as a power converter.

8. The heat exchanger claim 1 , wherein the heat exchanger comprises one or more pumps, the one or more pumps being arranged to pump the first fluid through the first helical flow path in a first direction, and the second fluid through the second helical flow path in a second direction, wherein the second direction is opposed to the first direction.

9. A power converter comprising a heat exchanger according to claim 1 , wherein the heat exchanger is arranged to serve as a heat sink to cool the power converter.

10. A gas turbine engine for an aircraft comprising:
an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
a fan located upstream of the engine core, the fan comprising a plurality of fan blades;
a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft;
so a power converter; and
a heat exchanger according to claim 1 , wherein the heat exchanger is arranged to serve as a heat sink to cool the power converter.

Assignees

• Rolls Royce Plc

Inventors

• Gajanayake Chandana J
• Muthu Vivek
• Chatterjee Pradip
• Gupta Amit K

Classifications

• B64D33/08

  of power plant cooling systems · CPC title

• F28D7/022

  the conduits of two or more media in heat-exchange relationship being helically coiled, the coils having a cylindrical configuration · CPC title

• F28D2021/0087

  Fuel coolers · CPC title

• F28D7/0033 Primary

  the conduits for one medium or the conduits for both media being bent · CPC title

• F28D2021/0026

  for combustion engines, e.g. for gas turbines or for Stirling engines · CPC title