Leak detection for coaxial heat exchange system

• US 4,228,848 A
• Filed: 01/23/1979
• Issued: 10/21/1980
• Est. Priority Date: 01/23/1979
• Status: Expired due to Term

• Current Assignee: Grumman Allied Industries, Inc.
• Original Assignee: Grumman Energy Systems Incorporated
• Inventors: Wadkinson, George W. Jr.
• Primary Examiner(s): Richter, Sheldon
• Application Number:
  US06/005,804
• Time in Patent Office: 637 Days
• Field of Search: 165/11, 165/70, 165/134, 165/140, 165/141, 165/154, 165/156
• US Class Current: 165/134.1
• CPC Class Codes: F28D 7/106 consisting of two coaxial conduits or modules of two coaxial conduits
• CPC Class Codes: F28F 1/003 Multiple wall conduits, e.g. for leak detection leak-detection in metal cooled nuclear reactor steam generators F22B1/066

Abstract

A system having a tube-in-tube heat exchanger comprising three coaxial tubular members fitted one within the other with manifolding at each longitudinal end of the exchanger for the circulation of fluid through the outside tubular member in a counterflow direction to fluid passing through the inside tubular member such that heat is exchanged therebetween. A fluid is provided in the intermediate tubular member such that a leak in either the outer or inner tubular members can be detected. Each of the tubular members has integral radially inwardly projecting fins in its bore, the fins of the outer member being in good thermal contact with the intermediate member whose fins, in turn, are in good thermal contact with the inner member such that an effective heat flow path therebetween is provided.

Claims

1. In a heat exchange system:

a heat exchanger comprising at least outer, intermediate, and inner tubular members inserted one into the other and being in physical contact with one another, said outer and intermediate members having substantially longitudinally extending relieved areas in their bores that form outer and intermediate fluid passages therein, with the bore of said inner member forming a third fluid passage, the end portions of said outer tubular member having an expanded diameter with respect to the portion of said outer member intermediate said expanded end portions;

first coaxial end walls fixed at each end of said intermediate tubular member and extending transversely outwardly therefrom into a sealed relationship with the inside surface of said expanded diameter portions of said outer tubular member, second coaxial end walls spaced longitudinally outwardly of said first coaxial walls, said second walls being fixed to the outer surface of said inner tubular member and extending transversely outwardly therefrom into a sealed relationship with the inside surface of said expanded diameter portions of said outer tubular member, said end walls closing off said outer and intermediate longitudinal passages such that said fluid passages are isolated from one another and from said inner passage;

heat conducting means integrally formed in each of said tubular members, said means consisting of substantially longitudinally extending fins projecting radially inwardly, the fins of said outer member contacting the outer wall of said intermediate member, the fins of said intermediate member contacting the outer wall of said inner member such that there is a metal-to-metal heat exchange relationship between said members, each fin of said members being spaced from its adjacent fins to thus form in said outer and intermediate members said longitudinal fluid passages;

inlet and outlet ports opening on said passages in said members to permit the circulation of fluid therethrough;

detector means coupled to fluid in said intermediate passages to sense a condition of said intermediate fluid that signifies a leak in one of said tubular members; and

means for circulating fluid through said longitudinal passages of said outer member and through the bore of said inner member whereby heat is exchanged between the fluids.

2. The heat exchange system of claim 1 wherein said tubular members have a concentric relationship with one another.