CN112728986B

CN112728986B - Shell-and-tube multipass heat exchanger

Info

Publication number: CN112728986B
Application number: CN202011610461.2A
Authority: CN
Inventors: 马志刚; 韩嘉兴
Original assignee: Suzhou Bmc Sealing Technology Co ltd
Current assignee: Suzhou Bmc Sealing Technology Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-06-24
Anticipated expiration: 2040-12-30
Also published as: CN112728986A

Abstract

The invention discloses a shell-and-tube multi-pass heat exchanger, which comprises a first flange, a second flange with a medium cavity and a sealing assembly for axially and hermetically connecting the first flange and the second flange, wherein the sealing assembly comprises an inner supporting ring, an outer supporting ring and a sealing ring with a hollow inner cavity, the sealing ring is arranged between the inner supporting ring and the outer supporting ring, the inner supporting ring is provided with a medium introducing hole, the medium introducing hole penetrates through the inner side wall and the outer side wall of the inner supporting ring, the inner side periphery of the sealing ring is provided with a medium access hole communicated with the hollow inner cavity, and a tube box is communicated with the medium access hole through the medium introducing hole. According to the shell-and-tube multi-pass heat exchanger disclosed by the invention, the temperature of each part in the circumferential direction of the sealing ring is consistent, the stress is uniform, so that the sealing assembly can be always in close contact with the first flange and the second flange, and the sealing effect is good.

Description

Shell-and-tube multipass heat exchanger

Technical Field

The invention relates to the field of sealing, in particular to a shell-and-tube multi-pass heat exchanger.

Background

The heat exchanger is a device for realizing heat exchange of cold and hot fluids, in order to improve the heat exchange efficiency of the heat exchanger and improve the heat transfer performance, a mode of increasing the flow of the fluids in the tubes is generally adopted in the industry, and a plurality of partition plates are arranged in a cylinder at intervals to form a shell-and-tube multi-pass heat exchanger, such as a 2-tube pass, a 4-tube pass, a 6-tube pass, an 8-tube pass and the like. The shell-and-tube multi-pass heat exchanger is widely applied to the fields of nuclear power, petrochemical industry and the like.

The quality of the sealing performance has an important influence on the working efficiency of the heat exchanger. In a traditional sealing device, a flange is adopted to compress a sealing gasket between parts needing sealing, and the sealing gasket comprises a wound gasket, a coated gasket and the like. In actual operation, the shell-and-tube multi-pass heat exchanger has objective temperature difference between passes, and the temperatures of the flange parts corresponding to the multiple passes from the inlet to the outlet are inconsistent, so that the internal thermal stress of the flange is formed, the axial deformation of each node in the circumferential direction of the flange is inconsistent, the local loss of the circumferential sealing working stress of different nodes in the circumferential direction of the sealing gasket is caused, the sealing leakage is caused, and the leakage is easy to occur when the number of tube passes is more.

Disclosure of Invention

The invention aims to solve the problem that a sealing device of a shell-and-tube multi-pass heat exchanger in the prior art is easy to lose efficacy, and provides a shell-and-tube multi-pass heat exchanger with good sealing performance.

In order to achieve the purpose, the invention adopts the technical scheme that:

a shell-and-tube multipass heat exchanger comprises a first flange, a second flange with a medium cavity, and a sealing assembly used for axial sealing connection between the first flange and the second flange, wherein the second flange is also provided with a medium inlet and a medium outlet communicated with the medium cavity, the medium cavity comprises a plurality of tube boxes which are arranged on the second flange and are mutually separated, a plurality of heat exchange pipelines communicated with two adjacent tube boxes are arranged on the first flange, the sealing assembly comprises an inner supporting ring, an outer supporting ring and a sealing ring with a hollow inner cavity, the sealing ring is arranged between the inner supporting ring and the outer supporting ring, a medium introducing hole is arranged on the inner supporting ring and penetrates through the inner side wall and the outer side wall of the inner supporting ring, and the inner supporting ring is provided with a plurality of cavities which are not communicated with each other, the number and the positions of all the tube boxes correspond to those of all the hole cavities one by one, medium access holes communicated with the hollow inner cavity are formed in the peripheral part of the inner side of the sealing ring, one or more medium access holes are formed in the medium access holes, and all the medium access holes are communicated with the same tube box and communicated with the hollow inner cavity through the medium access holes.

Preferably, the inner support ring comprises a ring body with an inner hole, and at least one rib fixedly arranged on the ring body, and the inner hole of the ring body is divided into a plurality of cavities which are not communicated with each other by all the ribs.

Furthermore, a plurality of partition plates are arranged in the medium cavity, all the partition plates divide the medium cavity into a plurality of pipe boxes, and the ribs are connected between the partition plates and the first flange in a sealing mode.

Furthermore, the height of the ribs is consistent with that of the ring body, and two end faces in the height direction are respectively flush.

Preferably, the pipe box at least comprises a liquid inlet pipe box, a liquid outlet pipe box and at least one middle pipe box, the medium sequentially passes through the liquid inlet pipe box, the middle pipe box and the liquid outlet pipe box along the input direction, and the medium introducing hole is communicated with the liquid inlet pipe box.

Further, the medium inlet is communicated with the liquid inlet pipe box, and the medium outlet is communicated with the liquid outlet pipe box.

Preferably, the medium access hole has a plurality of holes arranged at intervals in a circumferential direction of the seal ring.

Preferably, the inner diameter of the seal ring is larger than the outer diameter of the inner support ring, a gap is provided between the inner circumferential portion of the seal ring and the outer side wall of the inner support ring along the radial direction, and the medium introducing hole communicate with each other through the gap.

Preferably, the outer peripheral portion of the seal ring is a clearance fit with the inner peripheral portion of the outer support ring.

Preferably, the first flange is formed with a mounting protrusion, the second flange is formed with a mounting groove, the sealing member is disposed in the mounting groove, the mounting protrusion is fittingly inserted into the mounting groove and pressed against the sealing member, and sealing layers are disposed on both axial end surfaces of the inner support ring, so that the inner support ring is sealingly connected between the mounting groove and the mounting protrusion.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: according to the shell-and-tube multi-pass heat exchanger, the tube pass medium in one tube box enters the sealing ring through the medium introducing hole and the medium introducing hole to form self-tightening stress of the sealing ring, and the circumferential parts of the sealing ring are uniform in temperature and stress, so that self-tightening sealing is realized, the sealing assembly can be always in close contact with the first flange and the second flange, and the sealing effect is good.

Drawings

FIG. 1 is a schematic diagram of a particular embodiment of a shell-and-tube multipass heat exchanger of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is an enlarged view of FIG. 2 at B;

FIG. 4 is an enlarged view at C of FIG. 2;

FIG. 5 is a schematic view of a seal assembly of the present embodiment;

FIG. 6 is a cross-sectional view taken along line D-D of FIG. 5;

FIG. 7 is a cross-sectional view E-E of FIG. 5;

wherein: 1. a first flange; 11. a heat exchange conduit; 12. mounting a boss;

2. a second flange; 211. a pipe box; 2111. a liquid inlet pipe box; 2112 (2112 a, 2112b, 2112 c), an intermediate header; 2113. a liquid outlet pipe box; 212. a partition plate; 22. a media inlet; 23. a media outlet; 24. mounting grooves;

3. a seal assembly; 31. an inner support ring; 311. a ring body; 312. ribs; 31a, a sealing layer; 310. a medium introduction hole; 32. an outer support ring; 33. a seal ring; 330. a medium access hole;

4. a shell side shell.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the specific embodiments.

Referring to fig. 1 and 2, a shell-and-tube multipass heat exchanger includes a first flange 1, a second flange 2 having a medium cavity, and a sealing assembly 3 for axially sealing connection between the first flange 1 and the second flange 2, wherein the second flange 2 is embodied as an autoclave having a flange connection portion, and is referred to as the second flange 2 for convenience.

The medium cavity comprises a plurality of pipe boxes 211 which are arranged on the second flange 2 and are mutually separated, and a plurality of heat exchange pipes 11 which are communicated with two adjacent pipe boxes 211 are arranged on the first flange 1. The heat exchanger further comprises a shell side shell 4 hermetically connected with the first flange 1, the shell side shell 4 and the first flange 1 form a multi-cavity cooler, and all heat exchange pipelines 11 extend into the shell side shell 4, so that heat exchange can be realized between a high-temperature high-pressure tube side medium and a low-temperature shell side medium in the shell side shell 4.

The medium chamber is provided with a plurality of partition plates 212 to divide the medium chamber into a plurality of header boxes 211, and the header boxes 211 at least include a liquid inlet header box 2111 and a liquid outlet header box 2113. In this example, an 8-pass heat exchanger is exemplified: in this embodiment, the tube box 211 further includes three intermediate tube boxes 2112, which are an intermediate tube box 2112a, an intermediate tube box 2112b, and an intermediate tube box 2112c, and the tube pass medium sequentially passes through the liquid inlet tube box 2111, the intermediate tube box 2112a, the intermediate tube box 2112b, the intermediate tube box 2112c, and the liquid outlet tube box 2113 along the input direction; the second flange 2 is further provided with a medium inlet 22 communicated with the liquid inlet pipe box 2111 and a medium outlet 23 communicated with the liquid outlet pipe box 2113. Tube pass media sequentially flow through each tube box 211 and the heat exchange pipeline 11 in the direction indicated by an arrow in fig. 1, and are subjected to multi-tube pass gradual heat exchange and cooling, the temperature of the tube pass media in the liquid inlet tube box 2111 is highest, and the temperature of the tube pass media in the liquid outlet tube box 2113 is lowest, so that the problems of uneven circumferential heating of the second flange 2, local tilting of a sealing gasket between the first flange 1 and the second flange 2 and the like are easily caused, and the sealing is ineffective.

Referring to fig. 3 and 7, the seal assembly 3 of the present embodiment includes an inner support ring 31, an outer support ring 32, and a seal ring 33 having a hollow inner cavity, wherein the seal ring 33 is disposed between the inner support ring 31 and the outer support ring 32.

The inner support ring 31 includes a ring body 311 having an inner hole, and at least one rib 312 fixedly disposed on the ring body 311, in this embodiment, there are 4 ribs 312 as shown in fig. 5, all the ribs 312 divide the inner hole of the ring body 311 into a plurality of cavities that are not communicated with each other, and the number and positions of the tube boxes 211 and the cavities are in one-to-one correspondence. The rib 312 is connected between the partition 212 and the first flange 1 in a sealing manner, the height of the rib 312 is the same as the height of the ring 311, and two end surfaces in the height direction are respectively flush, so as to provide support for the ring 311 and the whole sealing assembly 3.

As shown in fig. 3 and 6, the inner support ring 31 is provided with a medium introduction hole 310, the medium introduction hole 310 penetrates through the inner side wall and the outer side wall of the inner support ring 31, and the medium introduction hole 310 extends in the radial direction of the inner support ring. The inner periphery of the sealing ring 33 is opened with a medium access hole 330 communicating with the hollow cavity, one of the pipe boxes 211 is communicated with the medium access hole 330 through the medium access hole 310, in this embodiment, the number of the medium access holes 310 may be one or more, all the medium access holes 310 are communicated with the liquid inlet pipe box 2111 and are not communicated with other pipe boxes 211, and the medium access hole 330 is provided with a plurality of holes arranged at intervals along the circumferential direction of the sealing ring 33, so that the high-temperature pipe pass medium in the liquid inlet pipe box 2111 can be injected into and fill the cavity of the sealing ring 33.

Specifically, the inner diameter of the seal ring 33 is larger than the outer diameter of the inner support ring 31, the inner peripheral portion of the seal ring 33 and the outer side wall of the inner support ring 31 are arranged with a gap therebetween in the radial direction all the time, and the medium introduction hole 310 and the medium passage hole 330 communicate with each other via a gap therebetween; the outer peripheral portion of the seal ring 33 is clearance-fitted to the inner peripheral portion of the outer support ring 32. Thus, a space for radial deformation of the sealing ring 33 is provided between the inner support ring 31 and the outer support ring 32, and both axial end faces of the sealing ring 33 always abut against the first flange 1 and the second flange 2.

In this embodiment, the first flange 1 is formed with a mounting protrusion 12, the second flange 2 is formed with a mounting groove 24, the sealing component 3 is disposed in the mounting groove 24, the mounting protrusion 12 is fittingly inserted into the mounting groove 24 and pressed against the sealing component 3, sealing layers 31a are disposed on both axial end surfaces of the inner support ring 31, so that the inner support ring 31 is sealingly connected between the mounting groove 24 and the mounting protrusion 12, and the sealing layers 31a are specifically flexible graphite layers or flexible metal layers.

It should be noted that the inner support ring 31, the outer support ring 32 and the sealing ring 33 all have certain strength, wherein the sealing ring 33 also has certain rigidity, and all of the inner support ring 31, the outer support ring 32 and the sealing ring 33 can be made of metal or nonmetal materials, preferably metal materials. The outer wall surface of the sealing ring 33 may be coated with a soft material, such as silver, aluminum, copper, or may be electroplated with silver, copper, or the like, so that the sealing ring 33 is in close contact with the adjacent end surfaces of the first flange 1 and the second flange 2.

The sealing principle of the shell-and-tube multi-pass heat exchanger in the embodiment is as follows:

the first flange 1 and the second flange 2 are pressed against the sealing assembly 3 in the axial direction through the bolt connection, and the sealing ring 33 is in contact with the first flange 1 and the second flange 2 and forms an initial sealing stress. After the heat exchanger starts to operate, the pressure medium in the liquid inlet pipe box 2111 enters the inner cavity of the sealing ring 33 through the medium introducing hole 310 and the medium access hole 330, the medium in the sealing ring 33 generates self-tightening stress Fa from inside to outside along with the increase of the working temperature and the pressure, and under the action of the self-tightening stress Fa, the contact stress Fg on the contact surfaces of the sealing ring 33 and the two flanges is gradually increased, so that self-tightening sealing is realized.

In the shell-and-tube multi-pass heat exchanger of this embodiment, after the tube-pass hot fluid medium is subjected to multi-pass heat exchange, the temperature is gradually reduced (in other embodiments, the temperature of the tube-pass medium is gradually increased, and the sealing principle of the sealing assembly 3 is the same), the temperatures of the different tube boxes 211 in the circumferential direction are different, specifically, the temperatures of the joints of the first flange 1 and the second flange 2 with the liquid inlet tube box 2111 are the highest, the temperature of the joints with the liquid outlet tube box 2113 is the lowest, and the temperatures of the joints with the intermediate tube box 2112a, the intermediate tube box 2112b and the intermediate tube box 2112c are gradually reduced, because the tube boxes 211 are arranged at intervals, the temperature distribution in the circumferential direction of the first flange 1 and the second flange 2 is unbalanced, so that the thermal expansion of the joint elements such as bolts and flanges is different, the generated deformation is not coordinated, the sealing stress of the sealing ring 33 is not uniform, and the non-uniform sealing stress can be compensated by the self-tightening function of the sealing ring 33, thereby ensuring that the seal is continuously effective.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a shell-and-tube multipass heat exchanger, includes first flange, has the second flange of medium chamber, and is used for first flange with the sealing assembly of axial sealing connection between the second flange, the second flange still have with medium entry and medium export of medium chamber intercommunication, the medium chamber is including setting up on the second flange and each other a plurality of pipe case of mutual separation, be provided with on the first flange and communicate adjacent two many heat transfer pipes of pipe case, its characterized in that: the sealing assembly comprises an inner support ring, an outer support ring, and a sealing ring having a hollow inner cavity, the sealing ring being disposed between the inner support ring and the outer support ring, wherein, the inner support ring is provided with a medium introducing hole which penetrates through the inner side wall and the outer side wall of the inner support ring, the inner support ring comprises a ring body with an inner hole and at least one rib fixedly arranged on the ring body, the inner hole of the ring body is divided into a plurality of cavities which are not communicated by all the ribs, all the tube boxes correspond to all the cavities in one-to-one number and positions, and the inner periphery of the sealing ring is provided with one or more medium introducing holes communicated with the hollow inner cavity, and all the medium introducing holes are communicated with the same pipe box and communicated with the hollow inner cavity through the medium introducing holes.

2. A shell-and-tube multipass heat exchanger according to claim 1, characterized in that: the medium cavity is internally provided with a plurality of clapboards, all the clapboards divide the medium cavity into a plurality of pipe boxes, and the ribs are connected between the clapboards and the first flange in a sealing manner.

3. A shell-and-tube multipass heat exchanger according to claim 1, characterized in that: the height of the ribs is consistent with that of the ring body, and two end faces in the height direction are respectively flush.

4. A shell-and-tube multipass heat exchanger according to claim 1, characterized in that: the pipe box at least comprises a liquid inlet pipe box, a liquid outlet pipe box and at least one middle pipe box, a medium sequentially passes through the liquid inlet pipe box, the middle pipe box and the liquid outlet pipe box along the input direction, and a medium introducing hole is communicated with the liquid inlet pipe box.

5. A shell-and-tube multipass heat exchanger according to claim 4, characterized in that: the medium inlet is communicated with the liquid inlet pipe box, and the medium outlet is communicated with the liquid outlet pipe box.

6. A shell-and-tube multipass heat exchanger according to claim 1, characterized in that: the medium access hole has a plurality of holes arranged at intervals in a circumferential direction of the seal ring.

7. A shell and tube multi-pass heat exchanger according to claim 1, characterized in that: the inner diameter of the sealing ring is larger than the outer diameter of the inner support ring, the inner side circumference of the sealing ring and the outer side wall of the inner support ring are arranged along the radial direction with a gap all the time, and the medium introducing hole is communicated with the medium introducing hole through the gap.

8. A shell-and-tube multipass heat exchanger according to claim 1, characterized in that: the outer side periphery of the sealing ring is in clearance fit with the inner side periphery of the outer supporting ring.

9. A shell and tube multipass heat exchanger according to any one of claims 1 to 8, characterized in that: the sealing device comprises a first flange, a second flange and a sealing component, wherein a mounting bulge is formed on the first flange, a mounting groove is formed on the second flange, the sealing component is arranged in the mounting groove, the mounting bulge is inserted in the mounting groove in a matched mode and tightly pressed on the sealing component, and sealing layers are arranged on the end faces of two sides of the inner supporting ring, so that the inner supporting ring is connected between the mounting groove and the mounting bulge in a sealing mode.