Staged graphite foam heat exchangers

Patent metadata

Field	Value
Publication number	US-9951997-B2
Application number	US-201213365460-A
Country	US
Kind code	B2
Filing date	Feb 3, 2012
Priority date	Feb 4, 2011
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Shell-and-tube heat exchangers that utilize one or more foam heat transfer units engaged with the tubes to enhance the heat transfer between first and second fluids. The foam of the heat transfer units can be any thermally conductive foam material that enhances heat transfer. In an embodiment, a liquid distribution unit is employed that sprays a fluid to maximize the energy transfer through the use of large surface/volume ratio of the sprayed fluid. The spraying can be used in combination with or separately from the foam heat transfer units. Also, the tubes can be helically twisted around the liquid distribution unit so that the sprayed fluid impinges on the tubes. The shell-and-tube heat exchangers described herein are highly efficient, inexpensive to build, and corrosion resistant. The heat exchangers can be configured as an evaporator, a condenser, or for single phase cooling or heating thermal transfer applications.

First claim

The invention claimed is:

1. A heat exchange evaporator, comprising:
a shell having a longitudinal axis;
a tube bundle disposed within the shell, the tube bundle comprising:
a plurality of first tubes configured to convey a first fluid;
a first tube sheet; and
a second tube sheet, wherein the plurality of first tubes are arranged parallel to the longitudinal axis, each of the plurality of first tubes comprising:
an outer surface;
a first end joined to the first tube sheet in a manner to prevent fluid leakage between the first end and the first tube sheet; and
a second end joined to the second tube sheet in a manner to prevent fluid leakage between the second end and the second tube sheet;

a heat transfer member connected to and in thermal contact with the outer surfaces of the plurality of first tubes, the heat transfer member configured to provide a downward cross-flow, the heat transfer member comprising graphite foam;
and
a liquid distribution tube disposed within the shell parallel to the longitudinal axis, the liquid distribution tube is configured to spray a second liquid within the shell and cascade over the heat transfer member in a downward cross-flow pattern.

2. The heat exchange evaporator according to claim 1 , wherein the first end and the second end of each first tube of the plurality of first tubes are joined to the first tube sheet and the second tube sheet respectively by friction-stir welded joints.

3. The heat exchange evaporator according to claim 1 , wherein the shell, the first tube sheet, and the second tube sheet collectively define a chamber that contains the plurality of first tubes, the heat transfer member and the liquid distribution tube.

4. The heat exchange evaporator according to claim 1 , wherein the heat transfer member consists of graphite foam.

5. The heat exchange evaporator according to claim 1 , wherein the heat transfer member comprises a plurality of heat transfer members axially spaced from one another along the longitudinal axis of the shell.

6. The heat exchange evaporator according to claim 1 , wherein the heat transfer member is bonded to the outer surfaces of the plurality of first tubes with a thermally conductive adhesive.

7. The heat exchange evaporator according to claim 6 , comprising conductive ligaments disposed within the thermally conductive adhesive, the conductive ligaments being in intimate contact with the outer surfaces.

8. The heat exchange evaporator according to claim 1 , wherein the liquid distribution tube comprises a plurality of liquid distribution tubes.

9. The heat exchange evaporator according to claim 8 , wherein each of the plurality of liquid distribution tubes extends through a respective opening in the heat transfer member.

10. The heat exchange evaporator according to claim 8 , wherein at least one of the plurality of liquid distribution tubes is disposed above the tube bundle, and at least one of the plurality of liquid distribution tubes is disposed within the tube bundle.

11. The heat exchange evaporator according to claim 8 , wherein the plurality of liquid distribution tubes are disposed within the tube bundle.

12. The heat exchange evaporator according to claim 5 , wherein each of the heat transfer members has a substantially wedge-shaped body, and the plurality of the heat transfer members are configured to form a baffle assembly around the plurality of first tubes.

13. The heat exchange evaporator according to claim 12 , further comprising a metal plate joined to at least one of the heat transfer members.

14. The heat exchange evaporator according to claim 12 , wherein the baffle assembly forms a substantially helix-shape.

15. The heat exchange evaporator according to claim 1 , wherein the tubes of the plurality of first tubes are disposed so as to surround the liquid distribution tube, the liquid distribution tube configured to spray the second fluid therefrom in multiple directions so as to impinge on the outer surfaces of the tubes of the plurality of first tubes.

16. The heat exchange evaporator according to claim 1 , wherein the longitudinal axis of the shell and the plurality of first tubes are oriented horizontally or vertically.

17. The heat exchange evaporator according to claim 1 , wherein the plurality of first tubes and the liquid distribution tube are made of metal.

18. The heat exchange evaporator according to claim 1 , wherein the liquid distribution tube has an end that penetrates and is directly attached to the first tube sheet and an opposite end that penetrates and is directly attached to the second tube sheet.

19. The heat exchange evaporator according to claim 8 , wherein the plurality of liquid distribution tubes are cylindrical.

20. The heat exchanger evaporator of claim 1 , wherein the heat transfer member comprises a perimeter edge coupled to an interior surface of the shell around an entire interior perimeter of the shell.

21. A heat exchange evaporator, comprising:
a shell having a longitudinal axis;
a tube bundle disposed within the shell, the tube bundle comprising:
a plurality of first tubes configured to convey a first fluid;
a first tube sheet; and
a second tube sheet, wherein the plurality of first tubes are arranged parallel to the longitudinal axis, each of the plurality of first tubes comprising:
an outer surface;
a first end joined to the first tube sheet in a manner to prevent fluid leakage between the first end and the first tube sheet; and
a second end joined to the second tube sheet in a manner to prevent fluid leakage between the second end and the second tube sheet;

a plurality of circular heat transfer members, each circular heat transfer member connected to and in thermal contact with the outer surfaces of the plurality of first tubes, each of the circular heat transfer members comprising graphite foam, wherein the circular heat transfer members are axially spaced from one another along the tube bundle; and
a liquid distribution tube disposed within the shell parallel to the longitudinal axis, the liquid distribution tube is configured to spray a second liquid within the shell, the liquid distribution tube having a first diameter,
wherein each of the circular heat transfer members includes a plurality of tube openings therethrough, each of the plurality of first tubes extending through and in contact with a respective one of the plurality of tube openings,
wherein each of the circular heat transfer members further includes at least one fluid conducting opening therethrough to permit fluid communication between opposite sides of the circular heat transfer member, the liquid distribution tube extending through the fluid conducting opening,
wherein each fluid conducting opening has a second diameter larger than the first diameter of the liquid distribution tube, thereby forming a gap between the liquid distribution tube and the fluid conducting opening for fluid communication through the gap.

22. The heat exchange evaporator according to claim 21 , wherein each of the circular heat transfer members includes a funnel-shaped, concave portion surrounding the fluid conducting opening.

23. A heat exchanger tube bundle, comprising:
a first tube sheet and a second tube sheet spaced from the first tube sheet;
a fluid distribution tube configured to spray a fluid in multiple directions therefrom, the fluid distribution tube having an end that penetrates and is directly attached to the first tube sheet and an opp

Assignees

• Maurer Scott M
• Klett James W
• Lockheed Corp

Inventors

• Maurer Scott M
• Klett James W

Classifications

• F28D3/04

  Distributing arrangements · CPC title

• F28F2275/062

  by impact pressure or friction welding · CPC title

• F28F2009/226

  Transversal partitions · CPC title

• F28F9/22

  Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates · CPC title

• F28D3/02 Primary

  with tubular conduits · CPC title