Heat exchanger with flow obstructions to reduce fluid dead zones

Patent metadata

Field	Value
Publication number	US-10295282-B2
Application number	US-201514805125-A
Country	US
Kind code	B2
Filing date	Jul 21, 2015
Priority date	Jul 21, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A heat exchanger has at least one plate pair comprising first and second plates with a fluid flow passage defined between the first plate and second plates. The inlet opening and the outlet opening in each plate pair are proximate to a first end and an elongate flow barrier separates the fluid flow passage into inlet and outlet portions, wherein a gap through and the flow barrier is provided proximate to the second end of each plate pair. A flow obstruction is located in the gap of each plate pair, the flow obstruction having first and second arcuate sides and being spaced from the terminal end of the flow barrier. The flow obstruction is substantially crescent-shaped, such that a middle portion of the flow obstruction is wider than the opposed ends.

First claim

What is claimed is:

1. A heat exchanger comprising at least one plate pair, wherein each plate pair of said at least one plate pair comprises:
(a) a first plate, a second plate, a first end and a second end;
(b) a fluid flow passage for flow of a first fluid defined between the first plate and the second plate;
(c) an inlet opening and an outlet opening, wherein the fluid flow passage extends between the inlet opening and the outlet opening, and wherein the inlet opening and the outlet opening are proximate to the first end;
(d) an elongate flow barrier separating the fluid flow passage into an inlet portion in which the inlet opening is located, and an outlet portion in which the outlet opening is located, wherein the flow barrier extends from the first end toward the second end, the flow barrier having a terminal end proximate to the second end and spaced from the second end by a gap through which fluid flow communication is provided between the inlet portion and the outlet portion of the fluid flow passage; and
(e) a flow obstruction located in the gap, the flow obstruction having a middle portion, a pair of opposed ends, a first side and an opposed second side, wherein the first and second sides are arcuate, with the first side facing the terminal end of the flow barrier and spaced therefrom, wherein a central longitudinal axis of each of the first and second plates extends through the middle portion of the flow obstruction;
wherein the flow obstruction is crescent-shaped and the first and second sides of the flow obstruction meet at the opposed ends thereof;
wherein each of the first and second sides of the flow obstruction is smoothly and continuously rounded and describes a portion of a smoothly rounded shape, wherein the portion of the smoothly rounded shape described by the second side is larger than the portion of the smoothly rounded shape described by the first side;
wherein a width of the flow obstruction, as measured radially from a point along the central longitudinal axis, increases in a gradual manner from the opposed ends of the flow obstruction to the middle portion of the flow obstruction.

2. The heat exchanger of claim 1 , wherein the first side of the flow obstruction approximates an arc of a first circle having a center which lies on the central longitudinal axis, and the second side of the flow obstruction approximates an arc of a second circle having a center which lies on the central longitudinal axis, the centers of the first and second circles being spaced apart along said axis, and the second circle having a larger radius than the first circle;
wherein said point along the central longitudinal axis is the center of the first circle or the center of the second circle.

3. The heat exchanger of claim 1 , wherein the terminal end of the flow barrier is arc-shaped, and wherein an arcuate space of constant width is defined between the terminal end of the flow barrier and the first side of the flow obstruction, wherein the constant width is measured radially from a center of a semi-circle defining a curvature of the terminal end of the flow barrier.

4. The heat exchanger of claim 3 , wherein a curvature of the first side of the flow obstruction deviates away from a circular arc proximate to the opposed ends, such that a width of the arcuate space proximate to the opposed ends is larger than a width of the arcuate space at the middle portion of the flow obstruction.

5. The heat exchanger of claim 4 , wherein the flow barrier is straight and parallel to the central longitudinal axis extending between the first and second ends; and
wherein the flow obstruction is symmetrical about the central longitudinal axis.

6. The heat exchanger of claim 5 , wherein the flow obstruction has a transverse length between the opposed ends along a line which is perpendicular to the central longitudinal axis, and wherein a ratio of the transverse length to a maximum width of the flow barrier is at least 2:1.

7. The heat exchanger of claim 6 , wherein the second side of the flow obstruction is shaped in portions thereof immediately adjacent to the opposed ends such that an included angle between the transverse line and each of said portions immediately adjacent to the opposed ends is in the range from about 60 degrees to about 120 degrees.

8. The heat exchanger of claim 1 , wherein the opposed ends of the flow obstruction are shaped so as to extend inwardly toward one another and toward a sidewall of the flow barrier.

9. The heat exchanger of claim 8 , wherein the opposed ends of the flow obstruction have a bulbous shape, wherein each of the bulbous shapes is partly defined by an inwardly-extending surface provided on the first side of the flow obstruction, and wherein each of the bulbous shapes is further partly defined by an outwardly-extending surface provided on the second side of the flow obstruction.

10. The heat exchanger of claim 9 , wherein the opposed ends of the flow obstruction have a bulbous shape, wherein each of the bulbous shapes is partly defined by an inwardly-extending surface provided on the first side of the flow obstruction, and wherein each of the bulbous shapes is further partly defined by a smooth arcuate shape of the second side of the flow obstruction.

11. The heat exchanger of claim 1 , wherein the flow obstruction is formed by a pair of crescent-shaped protrusions extending upwardly from a base of each of the first and second plates, each of the crescent-shaped protrusions having a top surface; and
wherein each of the crescent-shaped protrusions has a height which is the same as a height of the first or second plate, and wherein the top surfaces of the crescent-shaped protrusions are sealingly joined together such that the flow obstruction is free of perforations.

12. The heat exchanger of claim 1 , wherein the flow obstruction is formed by a pair of crescent-shaped protrusions extending upwardly from a base of each of the first and second plates, each of the crescent-shaped protrusions having a top surface;
wherein each of the crescent-shaped protrusions has a height which is less than a height of the first or second plate;
wherein the crescent-shaped protrusions have top surfaces which are spaced apart so as to provide a gap between the top surfaces of the crescent-shaped protrusions; and
wherein the gap extends through the flow obstruction from the first side to the second side.

13. The heat exchanger of claim 12 , wherein the top surface of each said crescent-shaped protrusion is flat and parallel to the base of the first or second plate from which it extends, such that the gap is continuous and extends throughout an entire length and width of the flow obstruction; and
wherein the gap is of constant height.

14. The heat exchanger of claim 13 , wherein the gap has a height which is no more than about 25 percent of a height of the fluid flow passage.

15. The heat exchanger of claim 12 , wherein the top surface of each said crescent-shaped protrusion is flat and parallel to the base of the first or second plate from which it extends, such that the gap is continuous and extends throughout an entire length and width of the flow obstruction; and
wherein the top surface of each said crescent-shaped protrusion is downwardly sloped from the opposed ends of the flow obstruction toward the middle portion thereof, such that the gap has a maximum height in the middle portion of the flow obstruction.

16. The heat exchanger of claim 12 , wherein the top surface of each said crescent-shaped protrusion is flat and parallel to the base of the first or second plate from whi

Assignees

• Dana Canada Corp

Inventors

• Powell Eric W
• Bardeleben Michael
• So Allan K
• Buckrell Andrew
• Kenney Benjamin A

Classifications

• F28D21/0003

  the heat being recuperated from exhaust gases (F28D21/0014 takes precedence) · CPC title

• F28D9/005

  the plates having openings therein for both heat-exchange media · CPC title

• F28F13/06 Primary

  by affecting the pattern of flow of the heat-exchange media {(F28F13/003 takes precedence; static flow control means in header boxes F28F9/026)} · CPC title

• F28D9/0056

  with U-flow or serpentine-flow inside conduits; with centrally arranged openings on the plates · CPC title

• F28F13/02

  by influencing fluid boundary (boundary-layer control in general F15D) · CPC title