CN111811313A

CN111811313A - Tube plate assembly and heat exchanger with same

Info

Publication number: CN111811313A
Application number: CN202010803178.5A
Authority: CN
Inventors: 许倍强; 李�雨; 卢恩明; 张慧芳
Original assignee: Himile Mechanical Manufacturing Co Ltd
Current assignee: Himile Mechanical Manufacturing Co Ltd
Priority date: 2020-08-11
Filing date: 2020-08-11
Publication date: 2020-10-23

Abstract

A tube plate assembly includes an anti-corrosion tube plate made of an anti-corrosion material and having at least one first tube hole formed therein. The tube sheet assembly also includes a base plate having at least one second tube aperture formed therein that aligns with a corresponding first tube aperture when the corrosion protection tube sheet is installed with the base plate. Wherein a first groove is provided in the outer circumference of at least one of the first pipe holes, the first groove extending along at least a portion of the outer circumference of the first pipe hole. The tube plate assembly of the structure can reduce or eliminate the stress applied to the heat exchange tubes supported by the tube plate, and prolong the service life of the tube plate assembly. A heat exchanger having the tube sheet assembly is also disclosed.

Description

Tube plate assembly and heat exchanger with same

Technical Field

The present invention relates to the field of heat exchange equipment, and more particularly, to a tube sheet assembly and a heat exchanger including the same.

Background

Heat exchangers are widely used in industrial plants such as chemical plants. One common type of heat exchanger is a shell and tube heat exchanger which includes a shell and a plurality of heat exchange tubes contained within the shell. The shell-and-tube heat exchanger is also provided with a tube plate, and two ends of the heat exchange tube are supported on the tube plate.

In applications where the medium used to perform the heat exchange is corrosive, heat exchange tubes made of a corrosion resistant material such as silicon carbide are typically used, and the tube sheets are made of Polytetrafluoroethylene (PTFE) material.

However, in use, such silicon carbide heat exchangers present problems that affect the efficient operation of the heat exchanger. Specifically, the metal tube plate and the silicon carbide heat exchange tube have a small coefficient of thermal expansion, and the position of the silicon carbide heat exchange tube in the housing has also been fixed by a member such as a baffle plate. While the PTFE used to form the tubesheets has a relatively high coefficient of thermal expansion. For example, for a tubesheet having a diameter of 500mm at ambient temperature, the diameter would increase by 8mm at a temperature of 140 ℃, which in turn would cause a substantially radial displacement of the tubesheet holes in the tubesheet.

Therefore, the difference in thermal expansion coefficient between the metal tube plate, the silicon carbide heat exchange tube and the PTFE tube plate causes the heat exchange tube to be subjected to a shearing force due to expansion and contraction of the tube plate. The shearing force applied to the heat exchange tube can cause the unilateral stress of the sealing ring at the connecting part between the heat exchange tube and the tube plate, damage to the sealing ring is caused, the leakage of materials in the heat exchanger is caused, and the heat exchange tube can be broken even under the action of the shearing force in serious conditions. Therefore, the service life of the existing heat exchangers of the above type at high temperatures is difficult to guarantee.

Therefore, in the field of heat exchangers, there is a need for further improvement of the structure of the heat exchanger to reduce stress applied to the heat exchange tubes of the heat exchanger, thereby improving the lifespan of the heat exchanger.

Disclosure of Invention

The present invention has been made to solve at least one of the problems occurring in the prior art as described above. The object of the present invention is to provide a heat exchanger of improved construction which is capable of reducing or even eliminating the stresses exerted on the heat exchange tubes by the tube sheet and thereby extending the useful life of the heat exchanger.

A tube sheet assembly of the present invention comprises:

the anti-corrosion pipe plate is made of anti-corrosion materials, and at least one first pipe hole is formed in the anti-corrosion pipe plate; and

the base plate is provided with at least one second pipe hole, and when the anti-corrosion pipe plate and the base plate are installed together, the second pipe hole is aligned with the corresponding first pipe hole;

wherein a first groove is provided in the outer circumference of at least one of the first pipe holes, the first groove extending along at least a portion of the outer circumference of the first pipe hole.

The corrosion resistant tube sheet may be made of a corrosion resistant material such as PTFE and the base plate may be made of a stronger material such as a metal such as stainless steel.

In the tube plate assembly with the structure, the first groove arranged around the first tube hole absorbs the displacement of the first tube hole caused by the volume change of the tube plate when the tube plate assembly expands with heat and contracts with cold due to the temperature rise and fall, so that the heat exchange tube is supported on the tube plate in a floating manner. Therefore, the shearing stress born by the heat exchange tube can be reduced and eliminated, and the service life of the heat exchanger is prolonged.

Further, it is preferable that at least one second groove is further formed on a portion of the corrosion prevention tube plate, which is free from the first tube hole.

The provision of the second groove further counteracts the effects of temperature changes on the tube plate volume changes, thereby helping to relieve stresses imposed on the heat exchange tubes and extending the life of the heat exchanger.

In addition, it is preferable that fixing grooves are formed on a side of the base plate facing away from the anticorrosive tube plate, fixing holes are provided in the fixing grooves, and the fixing holes are aligned with corresponding ones of the first tube holes; and a fixing part is formed on one surface of the anti-corrosion tube plate facing the substrate, extends into the fixing hole and covers the inner wall of the fixing hole, so that a second tube hole is formed.

More preferably, the fixing part further extends into the fixing groove and fills at least a portion of the fixing groove except for the fixing hole.

Through the arrangement of the fixing part, particularly through enabling the fixing part not to extend and wrap at least one part of the base plate made of metal, the rigidity of the anti-corrosion tube plate can be enhanced, the shearing stress generated on the heat exchange tube by the change of the volume of the anti-corrosion tube plate can be resisted, the risk of fracture of the heat exchange tube is further reduced, and the deformation caused on the anti-corrosion tube plate made of PTFE can be reduced under the negative pressure vacuum state.

Preferably, the first tube hole has a stepped portion formed therein, a bottom of the first groove being in a range defined by a first boundary line and a second boundary line as described below, wherein the first boundary line is at a position spaced apart from the stepped portion by 10mm in a direction away from the base plate, and the second boundary line is at a position of a surface of the anticorrosive tube plate facing the base plate, and the first groove does not penetrate through the anticorrosive tube plate. This depth setting of the first groove can reduce, or even eliminate, compression of components such as the seal ring when the corrosion protection tube sheet expands.

Preferably, the bottom of the first groove is flush with or passes over the step.

Further preferably, the radial distance from the inner side wall of the first groove to the step is less than 10mm, preferably 1-3 mm. This ensures the connection stability of the screw insert.

Wherein, the width of the first groove is more than or equal to 0.5mm, and is preferably in the range of 0.5-5 mm.

In addition, the thickness from the groove bottom of the first groove to the bottom of the corrosion-resistant tube plate is more than or equal to 1.5mm, and preferably ranges from 2 mm to 3 mm.

The first slot is sized to help better relieve shear stresses imposed on the heating tube by the tubesheet.

Preferably, the depth of the second groove is less than or equal to the depth of the first groove.

For the anchoring portion, the thickness of the portion of the anchoring portion in the anchoring hole is less than 10mm, preferably in the range 1-3 mm; and/or the thickness of the part of the fixation part filling in the fixation groove is less than 10mm, preferably in the range of 1-3 mm.

With regard to the structure for supporting the heat exchange tube on the tube plate, in a preferred structure, a first seal ring is provided on the step portion, a threaded sleeve is inserted into the first tube hole, one end of the heat exchange tube is fitted into the threaded sleeve, and the first seal ring is compressed between the threaded sleeve and the step portion.

Preferably, a connecting structure for assisting in fastening the corrosion-resistant tube plate and the base plate together is further arranged. Specifically, in a preferred structure, at least one first fastening hole is formed in the corrosion prevention pipe plate, and at least one second fastening hole is formed in the base plate and is aligned with the first fastening hole, wherein the pipe plate assembly further comprises a fastening bolt assembly, and the fastening bolt assembly penetrates through the first fastening hole and the second fastening hole, so that the corrosion prevention pipe plate and the base plate are fixed together.

In the above tube sheet assembly, the base plate may be made of a metal material, and the corrosion-resistant tube sheet is made of a teflon material.

Also disclosed is a heat exchanger comprising a tube sheet assembly as described above.

Further, the heat exchanger includes a shell and a tube box, and the tube plate assembly is disposed between the shell and the tube box.

Drawings

There is shown in the drawings, which are incorporated herein by reference, non-limiting preferred embodiments of the present invention, the features and advantages of which will be apparent. Wherein:

FIG. 1 shows a perspective view of a tube sheet assembly of the present invention.

Fig. 2a shows a perspective view of the base plate of the tube sheet assembly of fig. 1, wherein the side of the base plate facing the corrosion protection tube sheet is shown.

Fig. 2b shows another perspective view of the base plate shown in fig. 2a, wherein the side of the base plate facing away from the corrosion protection tube sheet is shown.

FIG. 3 illustrates a cut-away perspective view of the tube sheet assembly of FIG. 1 for use in a heat exchanger, wherein the tube sheet assembly is shown installed with a tube box of the heat exchanger.

Fig. 4 shows an enlarged view of portion a of fig. 3, showing a preferred embodiment of the support structure for supporting the heat exchange tubes on the tube sheet.

Fig. 5 shows an enlarged view of part B of fig. 3, showing a preferred embodiment of the connection means between the anti-corrosion tube sheet and the base plate of the tube sheet assembly.

FIG. 6 shows a cross-sectional view of a heat exchanger of the present invention showing the tube sheet assembly sandwiched between the shell and the tube box.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It is to be understood that the preferred embodiments of the present invention are shown in the drawings only, and are not to be considered limiting of the scope of the invention. Various obvious modifications, changes and equivalents of the embodiments of the invention shown in the drawings can be made by those skilled in the art, and all of them are within the scope of the invention.

FIG. 1 illustrates a perspective view of a tube sheet assembly 100 of the present invention. As shown in the drawings, the tube sheet assembly 100 basically includes two parts, i.e., a corrosion prevention tube sheet 110 and a base plate 120, and the corrosion prevention tube sheet 110 and the base plate 120 are stacked together. The corrosion-resistant tube plate 110 is made of a material that can resist acid and alkali corrosion, such as PTFE, and the base plate 120 is made of a material having higher strength, such as a metal material like stainless steel.

As can be seen more clearly in fig. 1, at least one, and usually a plurality of first tube holes 111 are formed in the corrosion prevention tube plate 110, and the first tube holes 111 are through holes formed through the thickness of the corrosion prevention tube plate 110. The first tube aperture 111 is preferably threaded to mate with a threaded insert 131 as described later in connection with fig. 4. The radial distance t from the inner side wall of the first groove 113 to the step portion is less than 10mm, preferably 1-3mm, so that the first groove 113 can not only ensure that the shearing action of the anti-corrosion tube plate 110 on the heat exchange tube 10 can be weakened, but also ensure the connection firmness of the thread insert 131. Also, the first tube aperture 111 is further preferably in the form of a stepped bore, including a step 115, as can be seen later in fig. 3 and 4. The stepped portion 115 divides the first tube hole 111 into a large diameter portion and a small diameter portion.

A first groove 113 is formed in the corrosion prevention tube plate 110 around the circumference of at least one first tube hole 111. Preferably, as shown in fig. 1, a corresponding first groove 113 of each first pipe hole 111 is formed around the circumference of the first pipe hole 111. The first groove 113 is shown as extending continuously around substantially the entire circumference of the first tube aperture 111, thereby forming a ring groove. However, the first groove 113 may extend only partially circumferentially around the first tube aperture 111, or the first groove 113 may be a plurality of discontinuous slots around the circumference of the first tube aperture 111.

The depth of the first groove 113 may be set according to the needs of the actual application. In a preferred arrangement, the groove bottom of the first groove 113 is located in a range L as shown in fig. 4, wherein one boundary line of the range L is a position spaced apart from the step portion 115 by 10mm in a direction away from the base plate 120, the other boundary line of the range L is a position of the surface of the anticorrosive tube plate 110 facing the base plate 120, and the first groove 113 does not penetrate the anticorrosive tube plate 110. In a preferred embodiment, the first groove 113 is formed to have a depth such that the bottom thereof is substantially flush with or exceeds the position of the step 115, or is closer to the substrate 120 than the step 115. In this way, the anti-corrosion tube plate 110 is prevented from expanding and deforming to press the first sealing ring 132, so that the shearing force applied to the heat exchange tube 10 can be further reduced and eliminated. Further, the depth of the first groove 113 is set so that the thickness of the anticorrosive tube sheet 110 at the portion where the first groove 113 is provided (i.e., the distance from the groove bottom of the first groove 113 to the bottom surface of the anticorrosive tube sheet 110) is 1.5mm or more, preferably in the range of 2 to 3 mm.

The width of the first groove 113 is preferably 0.5mm or more, more preferably in the range of 0.5 to 5 mm.

Further, a second groove 114 is also provided on the corrosion prevention tube plate 110. As shown in fig. 1, the second groove 114 may include at least one of a linear slot extending in a radial direction of the corrosion prevention tube plate 110 and a circumferential groove extending in a circumferential direction of the corrosion prevention tube plate 110. Wherein all first pipe apertures 111 are arranged in the area enclosed by the circumferential groove, as shown in fig. 1. The number and extent of the second slots 114 can be set as desired for the application. For example, in the example shown in fig. 1, two linear second grooves 114 are provided on the corrosion prevention tube plate 110, which extend from one side to the other side of the second grooves 114 in the form of circumferential grooves in the radial direction of the corrosion prevention tube plate 110. Also, the shape of the second slot 114 need not be linear or circular as shown, but may be designed as desired for a particular application. Further, it is preferable that the second groove 114 is provided on a portion of the corrosion prevention tube plate 110 where the first tube hole 111 is not provided. Further, the depth of the second groove 114 is preferably not greater than the depth of the first groove 113.

The corrosion prevention tube plate 110 and the base plate 120 may be attached to each other in various different ways, such as by screwing, bonding, and the like. In the configuration shown in the drawings, fastening holes 112 are formed in the corrosion prevention tube plate 110, the fastening holes 112 being aligned with corresponding fastening holes 124 (see fig. 2a and 2b) in the base plate 120, and the corrosion prevention tube plate 110 and the base plate 120 are fixed together by fastening means such as fastening screws. The fastening means will be described in detail in connection with fig. 4 below.

Fig. 2a and 2b show the structure of the base plate 120, wherein the corrosion protection tube plate 110, which is stacked with the base plate 120, is removed for better illustration. In a preferred structure, the substrate 120 is formed with a substantially circular fixing groove 123. In the area of the fixing groove 123, at least one, preferably a plurality of fixing holes 121 are formed, the fixing holes 121 preferably being in the form of through holes penetrating the thickness of the substrate 120. The number and position of the fixing holes 121 correspond to the first tube holes 111 on the corrosion prevention tube plate 110. Specifically, the fixing holes 121 may be the same in number as the first tube holes 111, and the fixing holes 121 are aligned with the corresponding first tube holes 111 after the anticorrosive tube plate 110 and the base plate 120 are mounted together. Fastening holes 124 are also formed in the base plate 120 to align with the corresponding fastening holes 112 in the first tube holes 111.

Turning to fig. 3, a cross-sectional view of the corrosion protection tube sheet 110 and base plate 120 assembled together is shown. In the preferred construction shown in this figure, the first tube holes 111 in the corrosion prevention tube plate 110 and the corresponding fastening holes 121 in the base plate 120 are aligned with each other, and the fastening holes 112 in the corrosion prevention tube plate 110 and the corresponding fastening holes 124 in the base plate 120 are also aligned.

As shown in fig. 3, a fixing portion 116 is disposed on a side of the corrosion prevention tube plate 110 facing the base plate 120, and the fixing portion 116 extends from a surface of the base plate 120 facing the corrosion prevention tube plate 110 to a surface of the base plate 120 facing away from the corrosion prevention tube plate 110. The fixing grooves 123 are formed on a surface of the base plate 120 facing away from the corrosion prevention tube plate 110, and the fixing holes 121 in the fixing grooves 123 are located at positions aligned with the corresponding first tube holes 111 in the corrosion prevention tube plate 110. The fixing portion 116 extends from a side of the corrosion prevention tube plate 110 facing the base plate 120 into the fixing hole 121 and covers an inner surface of the fixing hole 121, thereby forming a second tube hole 122. The heat exchange tube 10 of the heat exchanger may pass through a through-hole consisting of the first tube hole 111 and the second tube hole 122 which are aligned.

It is further preferable that the fixing portion 116 continues to extend toward the substrate 120 and at least partially fills a portion of the fixing groove 123 of the substrate 120 where the fixing hole 121 is not disposed. More preferably, the fixing portion 116 of the corrosion prevention tube plate 110 completely fills a portion of the fixing groove 123 of the base plate 120 where the fixing hole 121 is not provided.

Preferably, the thickness of the portion of the fixing portion 116 located in the fixing hole 121 is generally less than 10mm, preferably in the range of 1-3mm, and the thickness of the portion of the fixing portion 116 filled in the fixing groove 123 is generally less than 10mm, preferably in the range of 1-3 mm. The depth of the fixing groove 123 and the thickness of the fixing portion 116 may be the same or different, for example, the thickness of the fixing portion 116 may be smaller than the depth of the fixing groove 123.

Fig. 4 shows a partially enlarged view of a portion a of fig. 3, illustrating an exemplary structure for supporting one end of the heat exchange tube 10 in the tube sheet assembly 100. Here, the heat exchange tube 10 is made of a material resistant to acid and alkali corrosion, such as silicon carbide, silicon nitride, graphite, etc., and preferably a silicon carbide heat exchange tube may be selected.

As shown in fig. 4, one end of the heat exchange tube 10 is inserted into a through-hole of the tube sheet assembly 100 including a first tube hole 111 and a second tube hole 122. The heat exchange tube 10 has an outer diameter substantially equal to the inner diameter of the small diameter portion of the first tube hole 111 and the second tube hole 122, and is fitted with the inner walls thereof with a gap. And a screw boss 131 is inserted into the large-diameter portion of the first pipe hole 111, and an outer wall of the screw boss 131 is fitted to an inner wall of the large-diameter portion of the first pipe hole 111. For example, in the case where the first pipe hole 111 includes an internal thread, the nut 131 may have an external thread, and the nut 131 is fixed in the first pipe hole 111 by engagement between the internal thread and the external thread. The end of the heat exchange tube 10 is fitted in the thread insert 131.

A first packing 132 is provided on the step portion 115 of the first pipe hole 111, and the first packing 132 is compressed between the bottom of the screw sleeve 131 and the step portion 115 to perform a sealing function. In addition, the compressed first sealing ring 132 can also function to hug the end of the heat exchange tube 10. Fig. 5 is an enlarged view of portion B of fig. 3, showing a preferred connection between the corrosion protection tube sheet 110 and the base plate 120.

In the preferred coupling device shown in fig. 5, the fastening hole 112 provided in the corrosion prevention tube plate 110 is a stepped hole in which a first stepped portion 117 and a second stepped portion 118 are provided, and a plug 141 is inserted in a portion of the fastening hole 112 above the first stepped portion 117.

The fastening hole 124 is aligned with the fastening hole 112, and the fastening screw 143 is inserted into the fastening hole 124. The fastening screw 143 includes a head 144 and a shaft 145, the head 144 being supported by the second step 118, and a top surface of the head 144 being substantially flush with the first step 117 of the fastening hole 112 (and with a bottom surface of the plug 141).

A second packing 142 is provided at the step portion 117 of the fastening hole 112, and the second packing 142 is compressed by the plug 141 to perform a sealing function.

Of course, other connecting devices may be used to connect the corrosion protection tube plate 110 and the base plate 120, such as the above-mentioned bonding, and the fastening holes 112, 124 in the corrosion protection tube plate 110 and the base plate 120 may be omitted. Alternatively, in the case of screw connection, only one fastening screw may be included, the head portion of which is received in the large-diameter portion of the fastening hole 112, and the shaft portion of which protrudes into a portion below the first stepped portion 117 of the fastening hole 112, with the second seal ring 142 provided between the stepped portion 117 and the bottom of the head portion of the fastening screw.

The tube sheet assembly 100 is described above in a preferred configuration. Modifications to the tube sheet assembly 100 that would be obvious to one skilled in the art based on the above disclosure are within the scope of the invention.

For example, in the above disclosed structure, the first tube hole 111 has a larger diameter, and the second tube hole 122 in the base plate 120 has a smaller diameter. However, the first tube bore 111 and the second tube bore 122 may be the same diameter, and the threaded insert 131 may extend from the first tube bore 111 to the second tube bore 122 as known. Also, the thread inserts 131 may be interference-fitted with both the inner walls of the first and second pipe holes 111 and 122 and the outer surface of the heat exchange pipe 10 to perform a sealing function, and thus the first sealing ring 132 may be omitted.

In the above disclosed structure, the corrosion prevention tube plate 110 is preferably formed with the fixing portion 116 covering the inner wall of the fixing hole 121 of the base plate 120 and the fixing groove 123 of the base plate 120. The fixing portion 116 is also optional, and the object of the present invention can be basically achieved if the fixing portion 116 is omitted.

For another example, the fixing portion 116 of the corrosion prevention tube plate 110 is also an optional structure. In other words, the corrosion prevention tube plate 110 and the base plate 120 may be connected to each other only by fastening screws or the like. Also, the second pipe hole 122 may be directly formed in the substrate 120, instead of forming the fixing hole 121 first and then forming the second pipe hole 122 by wrapping the inner wall of the fixing hole 121 by the fixing portion 116.

Further, as shown in FIG. 6, the tube sheet assembly 100 may be used in a shell and tube heat exchanger, such as disposed between the tube box 20 and the shell 30 of the heat exchanger. Shown in fig. 6 is a cross-sectional view of one end of the heat exchanger. It will be appreciated by those skilled in the art that the other end of the heat exchanger, not shown, also has the same construction, including the tube box 20 and the tube sheet assembly 100 sandwiched between the tube box 20 and the shell 30. In the configuration shown in the drawings, the corrosion prevention tube plate 110 is located at a side close to the tube box 20, and the base plate 120 is located at a side close to the shell 30. In this configuration, the tube side of the heat exchanger may be fed with a corrosive fluid. In addition, it is also within the scope of the present invention to place the base plate 120 on the side near the tube box 20 and the corrosion protection tube plate 110 on the side near the shell 30, depending on the actual requirements, in which case the corrosive fluid may be introduced in the shell side. In addition, the tube sheet assembly 100 may also be used in other configurations of shell and tube heat exchangers.

Claims

1. A tube sheet assembly, comprising:

a base plate having at least one second tube aperture formed thereon that aligns with a corresponding first tube aperture when the corrosion protection tube sheet is installed with the base plate;

wherein a first groove is provided in an outer circumference of at least one of the first pipe apertures, the first groove extending along at least a portion of the outer circumference of the first pipe aperture.

2. The tube sheet assembly of claim 1, wherein at least one second groove is further formed in a portion of the corrosion resistant tube sheet that is free of the first tube aperture.

3. The tube sheet assembly of claim 1, wherein a retaining groove is formed in a side of the base plate facing away from the corrosion resistant tube sheet, a retaining hole being disposed in the retaining groove, the retaining hole being aligned with a respective one of the first tube apertures;

and a fixing part is formed on one surface of the anti-corrosion tube plate facing the base plate, extends into the fixing hole and covers the inner wall of the fixing hole, so that the second tube hole is formed.

4. The tube sheet assembly of claim 3, wherein the securing portion further extends into the securing slot and fills at least a portion of the securing slot other than the securing aperture.

5. The tube sheet assembly according to claim 1, wherein the first tube hole has a stepped portion formed therein, wherein a bottom of the first groove is in a range defined by a first boundary line and a second boundary line, the first boundary line being at a position spaced apart from the stepped portion by 10mm in a direction away from the base plate, the second boundary line being at a position of a surface of the anticorrosive tube sheet facing the base plate, and wherein the first groove does not penetrate the anticorrosive tube sheet; and/or

The radial distance from the inner side wall of the first groove to the step part is less than 10mm, and preferably 1-3 mm.

6. The tube sheet assembly of claim 5, wherein a bottom of the first slot is flush with or passes over the step.

7. The tube sheet assembly of claim 1, wherein the first groove has a width of 0.5mm or greater, preferably in the range of 0.5-5 mm.

8. The tube sheet assembly of claim 1, wherein the thickness of the groove bottom of the first groove to the bottom of the corrosion resistant tube sheet is 1.5mm or greater, preferably in the range of 2-3 mm.

9. The tube sheet assembly of claim 2, wherein the depth of the second groove is less than or equal to the depth of the first groove.

10. The tube sheet assembly of claim 4, wherein the portion of the fixation portion in the fixation hole has a thickness of less than 10mm, preferably in the range of 1-3 mm; and/or

The thickness of the part of the fixing part which fills in the fixing groove is less than 10mm, preferably in the range of 1-3 mm.

11. The tube sheet assembly according to claim 5 or 6, wherein a first seal ring is provided on the stepped portion, a boss is inserted into the first tube hole, one end of the heat exchange tube is fitted into the boss, and the first seal ring is compressed between the boss and the stepped portion.

12. The tube sheet assembly of claim 1, wherein at least one first fastening hole is provided in the corrosion protection tube sheet and at least one second fastening hole is provided in the base plate in alignment with the first fastening hole, wherein the tube sheet assembly further comprises a fastening bolt assembly that passes through the first and second fastening holes to help secure the corrosion protection tube sheet and the base plate together.

13. The tube sheet assembly of claim 1, wherein the first groove is an annular groove extending around an entire periphery of the first tube aperture.

14. The tube sheet assembly of claim 1, wherein the base plate is made of a metal material and the corrosion resistant tube sheet is made of a polytetrafluoroethylene material.

15. A heat exchanger, characterized in that it comprises a tube sheet assembly according to one of claims 1 to 14.