Coaxial gas-liquid heat exchanger with thermal expansion connector

摘要

A co-axial gas-liquid heat exchanger such as a charge air cooler comprises at least three concentric tubes forming at least two annular flow passageways. One end of the inner tube is rigidly attached to the middle tube by a thermal expansion connector including an inner connecting portion secured to the first end of the inner tube, an outer connecting portion secured to an inner surface of the middle tube; and one or more webs connecting the inner connecting portion to the outer connecting portion. The webs extend across the annular gas flow passageway but permit the hot gas to flow therethrough. The other end of the inner tube is free to expand in the longitudinal direction, relative to the middle and outer tubes. In some embodiments, the inner connecting portion forms part of a central plug portion which blocks an end of the inner tube.

主权项

1. A concentric tube heat exchanger, comprising:
a) a radially outer tube having a first end and a second end; b) a radially inner tube concentric with the outer tube, the inner tube having a first end and a second end; c) a middle tube located between, and concentric with, the inner and outer tubes, wherein the middle tube has a first end and a second end, wherein an annular gas flow passage is formed between the inner tube and the middle tube, wherein an annular coolant flow passage is formed between the middle tube and the outer tube, and wherein the outer, inner and middle tubes extend along a longitudinal axis; d) a connector comprising:
(i) a radially inner connecting portion rigidly connected to the first end of the inner tube;(ii) a radially outer connecting portion having a radially inner surface and a radially outer surface, both of which surfaces are parallel to the longitudinal axis, with the outer surface being rigidly connected to a radially inner surface of the middle tube;(iii) one or more webs extending angularly relative to both a radial direction and the longitudinal axis, and extending between the inner connecting portion and the outer connecting portion, wherein each of the one or more webs has a radially inner end rigidly connected to the inner connecting portion and a radially outer end rigidly connected to the outer connecting portion, and wherein the one or more webs permit gas to flow into the annular gas flow passage; and(iv) a blocking portion which blocks the first end of the inner tube, wherein the inner connecting portion and the blocking portion together form a central plug portion which is rigidly connected to the first end of the inner tube, wherein the inner connecting portion and the blocking portion are integrally formed, wherein the central plug portion is in the shape of a cup with the inner connecting portion forming a cylindrical side wall of the cup and the blocking portion forming a bottom of the cup, wherein the cup has an open top facing outwardly of the first end of the inner tube, and wherein the blocking portion is recessed inwardly along the longitudinal axis from the first end of the inner tube; and e) a turbulence-enhancing insert provided in the gas flow passageway, wherein the insert is in contact with a radially outer surface of the inner tube and a radially inner surface of the middle tube, and wherein the turbulence enhancing insert in the annular gas flow passage is a corrugated fin, and wherein the fin is joined to the inner surface of the middle tube by brazing, and is not brazed or otherwise rigidly attached to the outer surface of the inner tube.