Extreme environment heat exchanger

Patent metadata

Field	Value
Publication number	US-9897398-B2
Application number	US-201414248614-A
Country	US
Kind code	B2
Filing date	Apr 9, 2014
Priority date	May 7, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The heat exchanger ( 10 ) includes a ceramic matrix composite ( 12 ) (stable at temperatures up to 1,650° C.) surrounding and defining a hot fluid conduit ( 14 ). A hardenable material ( 18 ) having a high thermal conductivity is formed into a heat transfer layer ( 16 ) surrounding the ceramic matrix composite ( 12 ). A metal pipe ( 20 ) is coextensive with the heat transfer layer ( 16 ) and defines at least a portion ( 22 ) of at least one cool fluid passage ( 24, 34, 54 ) defined adjacent to and in heat exchange relationship with the heat transfer layer ( 16 ) so that a fluid passing through the cool fluid passage ( 24, 34, 54 ) absorbs heat passing through the heat transfer layer ( 16 ) from the hot fluid passing through the hot fluid conduit ( 14 ).

First claim

What is claimed is:

1. An extreme environment heat exchanger for transferring heat from a hot fluid conduit to a cool fluid passage; the extreme environment heat exchanger comprising:
a. a ceramic matrix composite surrounding and defining the hot fluid conduit and configured so that a hot fluid passing along the conduit cannot pass out of the conduit through the ceramic matrix composite, the ceramic matrix composite also being configured to have mechanical stability at temperatures up to about 1,650 degrees Celsius;
b. a heat transfer layer surrounding and secured to the ceramic matrix composite, the heat transfer layer being made of a hardenable material; and,
c. a metal pipe coextensive with the heat transfer layer, the metal pipe also defining at least a portion of at least one cool fluid passage defined adjacent to and in heat exchange relationship with the heat transfer layer so that a fluid passing through the cool fluid passage absorbs heat passing through the heat transfer layer from the hot fluid passing through the hot fluid conduit, and further comprising the surrounding, coextensive metal pipe being circumferentially displaced from the heat transfer layer so that the cool fluid passage is a surrounding cool fluid passage defined between an interior surface of the displaced metal pipe and the exterior surface of the heat transfer layer, and a metal coil seal secured between the outer surface of the heat transfer layer and the interior surface of the circumferentially displaced metal pipe, wherein the coil seal overlaps itself thereby enabling differential thermal growth of the coil between the heat transfer layer and the metal pipe.

2. The extreme environment heat exchanger of claim 1 , wherein the hardenable material has thermal conductivity of at least 20 Btu/(hr. ft 2 ° F.).

3. The extreme environment heat exchanger of claim 1 , wherein the hardenable material is selected from the group consisting of metals including silicon, silver, copper, aluminum, nickel, and nickel alloys, and ceramics including boron nitride, tungsten carbide, and silicon carbide, and wherein the hardenable material is reinforced with at least one of chopped fibers, hard ceramic particles, soft ceramic particles, carbides, graphite, carbon, glass, silicone carbide, silicon nitride or boron nitride, and combinations thereof.

4. The extreme environment heat exchanger of claim 1 , wherein an exterior surface of the heat transfer layer defines a second portion of the at least one cool fluid passage so that the cool fluid passage is defined between the heat transfer layer and the surrounding metal pipe, and wherein the cool fluid passage is coextensive with the hot fluid conduit.

5. The extreme environment heat exchanger of claim 4 , further comprising a plurality of second portions of cool fluid passages defined within the exterior surface of the heat transfer layer so that a plurality of cool fluid passages are defined between the heat transfer layer and the surrounding metal pipe, and wherein the plurality of cool fluid passages are coextensive with the hot fluid conduit.

6. An extreme environment heat exchanger for transferring heat from a hot fluid conduit to a cool fluid passage; the extreme environment heat exchanger comprising:
a. a ceramic matrix composite surrounding and defining the hot fluid conduit and configured so that a hot fluid passing along the conduit cannot pass out of the conduit through the ceramic matrix composite, the ceramic matrix composite also being configured to have mechanical stability at temperatures up to about 1,650 degrees Celsius;
b. a heat transfer layer surrounding and secured to the ceramic matrix composite, the heat transfer layer being made of a hardenable material; and
c. a metal pipe coextensive with the heat transfer layer, the metal pipe also defining at least a portion of at least one cool fluid passage defined adjacent to and in heat exchange relationship with the heat transfer layer so that a fluid passing through the cool fluid passage absorbs heat passing through the heat transfer layer from the hot fluid passing through the hot fluid conduit, and further comprising the surrounding, coextensive metal pipe being circumferentially displaced from the heat transfer layer so that the cool fluid passage is a surrounding cool fluid passage defined between an interior surface of the displaced metal pipe and the exterior surface of the heat transfer layer, further comprising a plurality of portions of cool fluid passages defined within the exterior surface of the heat transfer layer, thereby increasing a surface area of the heat transfer layer exposed to a cooling fluid passing through the surrounding cool fluid, passage defined between the metal pipe and the heat transfer surface, and further comprising a metal coil seal secured between the outer surface of the heat transfer layer and the interior surface of the circumferentially displaced metal pipe, wherein the coil seal overlaps itself, and wherein the coil seal overlies the plurality of portions of cool fluid passages defined within the exterior surface of the heat transfer layer to form a plurality of cool fluid passages between the coil and the portions of cool fluid passages defined within the exterior surface of the heat transfer layer.

7. The extreme environment heat exchanger of claim 1 , further comprising a plurality of metal pipes, wherein each metal pipe defines a complete cool fluid passage within the pipe, and each metal pipe being also secured adjacent to and coextensive with the heat transfer layer.

8. The extreme environment heat exchanger of claim 7 , wherein the exterior surface of the beat transfer layer defines a plurality of channels configured so that one of the plurality of metal pipes is secured within each of the plurality of channels to increase a rate of heat transfer between the heat transfer layer and the cool fluid passages defined by the metal pipes.

9. The extreme environment heat exchanger of claim 1 , wherein exterior surface of the heat transfer layer is machined to surface finish tolerances of about 0.005″ (0.127 mm).

10. The extreme environment heat exchanger of claim 1 , wherein the heat transfer layer has a thickness that is between about one-half and about ten times a wall thickness of the ceramic matrix composite tube surrounded by the heat transfer layer.

11. The extreme environment heat exchanger of claim 1 , wherein the heat transfer layer has a thickness that is between about 1.27 millimeters and about 6.35 millimeters.

Assignees

• United Technologies Corp

Inventors

• Jarmon David C

Classifications

• F28F1/003

  Multiple wall conduits, e.g. for leak detection (leak-detection in metal cooled nuclear reactor steam generators F22B1/066) · CPC title

• Y10T29/49377

  Tube with heat transfer means · CPC title

• Y10T29/49361

  Tube inside tube · CPC title

• F28F21/04 Primary

  of ceramic; of concrete; of natural stone · CPC title

• F28F2265/26

  for allowing differential expansion between elements · CPC title