Shell and tube condenser and the heat exchange tube of a shell and tube condenser (variants)

Abstract

A heat exchange apparatus, and more particularly a condenser device, is provided. The condenser includes a housing with tubes that have grooves on the outer surface thereof, baffles, and inlet and outlet manifolds for tube-side and shell-side heat transfer fluids. An outside of each of the tubes is coated with a material having a low wetting coefficient. The baffles of the condenser are formed so, and the that the distance between the baffles decreases from the shell-side heat transfer fluid inlet manifold to the shell-side heat transfer fluid outlet manifold. The inner surfaces of the tubes have protuberances thereon and are coated with a material having a high adhesion resistance coefficient.

Claims

1. A shell-and-tube condenser, comprising: a shell, which houses a bundle of heat exchange tubes having grooves on their outer surfaces and fastened in place with tube plates, spacers, and inlets and outlets for tube space and shell space heat carriers; wherein the outer surfaces of the heat exchange tubes include a coating of a hydrophobic material, a distance between the spacers decreases from the inlet of the shell space heat carrier to its outlet and, a length of each of the spacers increases from the inlet of the shell space heat carrier to its outlet; the heat exchange tubes include ribs on inner surfaces thereof and a coating on the inner surfaces of a material with a high adhesion resistance coefficient.

2. The shell-and-tube condenser according to claim 1, wherein the distance between the spacers decreases so as to maintain constant average velocity of steam during every pass of the shell space heat carrier.

3. The shell-and-tube condenser according to claim 1, wherein the distance between the spacers decreases so as to maintain a constant ratio between an average volumetric flow rate of steam for every pass of the shell space heat carrier and a sectional area of an appropriate pass of the shell space heat carrier.

4. The shell-and-tube condenser according to claim 1, wherein the hydrophobic material is selected from the group consisting of nylon, polytetrafluorethylene and combinations thereof.

5. The shell-and-tube condenser according to claim 1, wherein the hydrophobic material which coats the outer surfaces of the heat exchange tubes has an interfacial angle in a range of 90°-150°.

6. The shell-and-tube condenser according to claim 1, wherein the grooves have a rounding with a radius of 0.04-0.1 of an outer diameter of the heat exchange tubes.

7. The shell-and-tube condenser according to claim 1, wherein a radius of a rounding of a sloping area on a surface between the grooves measures 0.3-2 of the outer diameter of the heat exchange tubes.

8. The shell-and-tube condenser according to claim 1, wherein the material with high the adhesion resistance coefficient comprises fluorine-containing material or sprayed metal.

9. The shell-and-tube condenser according to claim 1, wherein the ribs formed on the inner surfaces of the heat exchange tubes correspond to the grooves on the outer surface of the heat exchange tubes.

10. The shell-and-tube condenser according to claim 9, wherein the ribs and grooves are circular in shape.

11. The shell-and-tube condenser according to claim 9, wherein the ribs and groves are located at 0.1-10 times an outer diameter of the heat exchange tubes from one another.

12. The shell-and-tube condenser according to claim 9, wherein a height of the ribs is in a range of 0.5-10 mm.

Description

(1) This group of inventions is illustrated with the following diagrams.

(2) FIG. 1. The shell-and-tube condenser with a one-way feed of a heat carrier into the shell, and a condensate cooler. Overall view. Longitudinal section.

(3) FIG. 2. The shell-and-tube condenser with a one-way flow of a heat carrier in the shell space without a condensate cooler. Overall view. Longitudinal section.

(4) FIG. 3. The shell-and-tube condenser with a two-way feed of a heat carrier in the shell without a condensate cooler. Overall view. Longitudinal section.

(5) FIG. 4. A heat exchange tube of the shell-and-tube condenser with circular grooves on the outer surface. Overall view.

(6) FIG. 5. A heat exchange tube of the shell-and-tube condenser with helical grooves on the outer surface. Overall view.

(7) FIG. 6. A heat exchange tube of the shell-and-tube condenser with circular grooves on the outer surface and corresponding circular ribs on the inner surface. Longitudinal section.

(8) FIG. 7. A heat exchange tube of the shell-and-tube condenser with circular grooves on the outer surface and diamond-shape ribs on the inner surface. Longitudinal section.

(9) FIG. 8. A heat exchange tube of the shell-and-tube condenser with a helical groove on the outer surface and a corresponding diamond-shape ribs on the inner surface. Longitudinal section.

(10) FIG. 9. A heat exchange tube of the shell-and-tube condenser with circular grooves on the outer surface and inserts in the shape of perforated rings. Longitudinal section.

(11) The shell-and-tube condenser includes shell 1, distribution chamber 2 and turn chamber 3. Shell 1 houses a bundle of heat exchange tubes 4, fastened in place with tube plates 5, guiding spacers 6, shell side heat carrier inlet 7, outlet 8, tube-inside heat carrier inlet 9, outlet 10. The distance Sn between the spacers 6 decreases from inlet 7 to outlet 8, so that Sn>Sn+1. Heat exchange tubes 4 are coated with a hydrophobic material and carry grooves 11, due to which arcuate convex sections 12 form on the outer surface 4 of the tubes.

(12) Shell-and-tube condenser operates as follows.

(13) A coolant at a temperature below the steam saturation temperature is fed into the tubes at the temperature below the steam saturation temperature in the shell space 1 via inlet 9. The coolant circulates from inlet 9 to the distribution chamber 2, then, via heat exchange tubes 4 and the turn chamber 3 back to the distribution chamber 2 and outlet 10. The heat carrier in the shell space, that is to be cooled down, enters the shell space 1 via inlet 7. Coming into contact with the outer surface of tubes 4, it begins to partly condensate, flowing towards outlet 8. Droplets 13 of condensate form on the outer surface of the heat exchange tubes, most of which roll off arcuate segments 12 down into grooves 11. Residual condensate 14 is carried away by the flow of uncondensed shell space heat carrier, velocity of which is maintained by gradually decreasing the distance between the consecutive spacers 6 from inlet 7 of the shell space heat carrier to its outlet 8.

(14) According the second version, tubes 4 of the shell-and-tube condenser carry—in addition to the first version—ribs 15; also the inner surface of the tubes is coated with a high adhesion resistance material.

(15) This shell-and-tube condenser operates in a manner similar to the first version. Only a small quantity of salt particles 16 present in the coolant precipitates on the inner surface of tubes 4 thanks to the coat of a high adhesion resistance material on these surfaces, forming only the thin layer 17 of salt deposit. The coolant, interacting with ribs 15, generates eddies, which also impede deposition of salt 16 on the inner surface of the heat exchange tubes and breaks the previously formed layer 17 of salt by abrasion caused by the flow of the coolant and particles of salt 16 present in the coolant.

(16) Thanks to the above arrangements, the film of condensate that forms on the outer surface of heat exchange tubes is thin and, on the other hand, fewer salt deposits form on the inner surface of the tubes. This achieves the desired technological result: cutting down the risk of increased thermal resistance between the heat carriers inside and outside the tubes, while increasing the overall heat exchange coefficient between the heat carriers in the tubes and in the shell space. Due to the decreased contact surface required, tube bank can be made smaller and of lighter weight, rendering the entire shell-and-tube condenser smaller and of lighter weight.