Shell and tube heat exchangers

Patent metadata

Field	Value
Publication number	US-11306972-B2
Application number	US-201816173313-A
Country	US
Kind code	B2
Filing date	Oct 29, 2018
Priority date	Nov 1, 2017
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

A heat exchanger in one aspect includes a longitudinal shell and a transverse shell oriented transversely thereto. A J-shaped tube bundle carrying a tube-side fluid extends through the longitudinal and transverse shells from a first tubesheet in the longitudinal shell to a second tubesheet in the transverse shell. The first and second tubesheets are oriented perpendicular to each other. In a related aspect a dual heat exchanger unit includes a first longitudinal shell, a second longitudinal shell, and a common transverse shell extending transversely between and fluidly coupled to the longitudinal shells. The longitudinal shells may be parallel to each other. The shells are fluidly coupled directly together to form a common shell-side space between pairs of inlet and outlet tubesheets. A pair of J-shaped tube bundles is disposed in the dual heat exchanger unit for heating two tube-side fluids.

First claim

What is claimed is:

1. A heat exchanger comprising:
an elongated longitudinal shell defining a first shell-side space and a longitudinal axis;
an elongated transverse shell defining a second shell-side space and a transverse axis; the transverse shell oriented perpendicularly transversely to the longitudinal shell;
the transverse shell fluidly coupled to a first end of the longitudinal shell such that the second shell-side space is in fluid communication with the first shell-side space;
a tube bundle extending through the first and second shell-side spaces, the tube bundle comprising a plurality of tubes each having a first end coupled to a first tubesheet in the first shell-side space of the first longitudinal shell and a second end coupled to a second tubesheet in the second shell-side space of the transverse shell;
wherein the first and second tube-sheets are oriented non-parallel to each other;
wherein the tubes each include a straight short section disposed in the transverse shell and fluidly coupled to the second tubesheet, a straight long section disposed in the longitudinal shell and fluidly coupled to the first tubesheet, and a radiused tube bend therebetween;
wherein the transverse shell includes a tubeless space defining an auxiliary shell-side flow plenum at a first end portion of the transverse shell opposite a second end portion of the transverse shell attached to the second tubesheet, and a shell-side inlet nozzle on the transverse shell is coupled to the first end portion and arranged to introduce a shell-side fluid directly into the auxiliary flow plenum such that the shell-side fluid expands and undergoes a reduction in velocity before impinging the tubes in the transverse shell;
a shell-side fluid inlet head sealably joined to the first end portion of the transverse shell and a tube-side fluid outlet head sealably joined to the second tubesheet in the transverse shell;
wherein the longitudinal shell includes a shell-side outlet nozzle oriented perpendicularly to the shell-side inlet nozzle;
wherein the shell-side inlet nozzle is configured to direct the shell-side fluid towards the radiused tube bend of each tube; and
wherein the shell-side fluid auxiliary flow plenum in the transverse shell has an axial length DV measured along the transverse axis which extends from a terminal end of the shell-side fluid inlet head to a nearest point on the transverse shell where the longitudinal shell is attached to the transverse shell, the axial length DV being at least one quarter of a total axial length of the transverse shell measured along the transverse axis between the terminal end of the shell-side fluid inlet head to a second terminal end of the tube-side fluid outlet head to provide space for expanding the inlet shell-side fluid.

2. The heat exchanger according to claim 1 , wherein the longitudinal shell is coupled to the transverse shell inwards of and between opposing ends of the transverse shell.

3. The heat exchanger according to claim 2 , wherein the longitudinal shell is oriented perpendicularly to the transverse shell forming a T-shaped heat exchanger.

4. The heat exchanger according to claim 3 , wherein the longitudinal shell includes a tube-side inlet nozzle coaxially aligned with the longitudinal axis and a radial shell-side outlet nozzle transversely oriented to the longitudinal axis.

5. The heat exchanger according to claim 4 , wherein the shell-side outlet nozzle is located proximate to the first tubesheet.

6. The heat exchanger according to claim 4 , wherein the transverse shell includes a tube-side outlet nozzle coaxially aligned with the transverse axis at a first one of the ends of the transverse shell, and the shell-side inlet nozzle coaxially aligned with the transverse axis at a second one of the ends of the transverse shell.

7. The heat exchanger according to claim 1 , wherein the tubes are J-shaped collectively giving the tube bundle the same configuration.

8. The heat exchanger according to claim 1 , wherein the shell-side fluid flows into the auxiliary flow plenum from the shell-side inlet nozzle in an axial direction parallel to transverse axis of the transverse shell, and the shell-side fluid turns 90 degrees in the auxiliary plenum to enter the longitudinal shell.

9. The heat exchanger according to claim 1 , wherein the first tubesheet includes a first end portion having a first diameter, a second end portion having a second diameter, and an annular angled transition portion between the first and second end portions.

10. The heat exchanger according to claim 1 , further comprising a planar flow blocker plate oriented parallel to and spaced apart from an inboard face of the second tubesheet, the flow blocker plate sealably welded to the transverse shell forming a dead flow space between the second tubesheet and the flow blocker plate.

11. The heat exchanger according to claim 1 , further comprising a tube-side fluid inlet head sealably joined to the first tubesheet at a second end of the longitudinal shell to form a tube-side inlet flow plenum.

12. The heat exchanger according to claim 11 , further comprising a radially extending first shell-side outlet nozzle on the longitudinal shell which is oriented perpendicularly to the longitudinal axis of the longitudinal shell, and a radially-extending second shell-side outlet nozzle on the longitudinal shell opposite the first shell-side outlet nozzle, the first and second shell-side outlet nozzles being configured to discharge the shell-side fluid in opposite directions.

13. The heat exchanger according to claim 12 , wherein a tube-side fluid flows through the longitudinal shell in a first axial direction, and the tube-side fluid flows through the transverse shell in a second axial direction perpendicular to the first axial direction.

14. The heat exchanger according to claim 13 , wherein the tube-side fluid flows in a countercurrent arrangement to a shell-side fluid flowing through the longitudinal and transverse shells.

15. The heat exchanger according to claim 1 , wherein the shell-side inlet and outlet nozzles have respective diameters larger than the tubes of the tube bundle.

16. A method for reducing tube-side erosion in the heat exchanger according to claim 1 , the method comprising introducing the shell-side fluid through the shell-side inlet nozzle directly into the auxiliary flow plenum, expanding the shell-side fluid, and reducing the velocity of the shell-side fluid before impinging the tubes in the second transverse shell.

17. A heat exchanger comprising:
an inlet tubesheet and an outlet tubesheet;
an elongated longitudinal shell assembly defining a first shell-side space and a longitudinal axis;
the longitudinal shell assembly comprising opposing first and second ends, a circumferential sidewall extending between the first and second ends, a tube-side fluid inlet nozzle fluidly coupled to the inlet tubesheet, and a shell-side fluid outlet nozzle fluidly coupled to the circumferential sidewall;
an elongated transverse shell assembly fluidly coupled to the first end of the longitudinal shell, the transverse shell assembly defining a second shell-side space and a transverse axis oriented perpendicularly to the longitudinal axis of the longitudinal shell, the second shell-side space being in direct fluid communication with the first shell-side space;
the transverse shell assembly comprising opposing first and second ends, a circumferential sidewall extending between the first and second ends, a tube-side fluid outlet nozzle fluidly coupled to the outlet tubesheet, and a shell-side

Assignees

• Holtec International

Inventors

• Singh Krishna P

Classifications

• F28F9/26 Primary

  Arrangements for connecting different sections of heat-exchange elements, e.g. of radiators (connecting different sections in water heaters F24H9/14 {, connecting headers with inlet or outlet fittings F28F9/0246}) · CPC title

• F28D7/0075

  with particular circuits for the same heat exchange medium, e.g. with the same heat exchange medium flowing through sections having different heat exchange capacities or for heating or cooling the same heat exchange medium at different temperatures · CPC title

• F28D7/08

  the conduits being otherwise bent, e.g. in a serpentine or zig-zag (F28D7/10 takes precedence){(F28D7/0016 and F28D7/0033 take precedence)} · CPC title

• F28F2275/06

  by welding · CPC title

• F28F21/082

  from steel or ferrous alloys · CPC title