A seal for easily installing a heat exchange tube and an air preheater with the seal

Abstract

The utility model discloses a seal, and particularly relates to a seal that is easy to install a heat exchange tube and an air preheater with the seal, comprising: a proximal end, an arc segment and a tail end, wherein the proximal end and the tail end are connected by the arc segment, the proximal end comprises a proximal boss, a proximal outer lip and a proximal inner lip, and the tail end comprises a tail boss, a tail outer lip and a tail inner lip. The seal is used to install the heat exchange tube on the tube sheet in a plug-in manner, without welding the tube sheet and the heat exchange tube, which greatly reduces the difficulty of installing the heat exchange tube; stainless steel composite heat-conducting tubes, rare earth alloy tubes or segmented anti-corrosion heat exchange tubes are used, with a flat and smooth surface, which is easy to maintain a seal with the seal; at the same time, these heat exchange tubes have a small expansion coefficient and expand moderately in the working state, which will not over-extend the seal while enhancing the sealing effect between the seal and the seal, which is beneficial to protecting the seal and extending its service life.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange equipment, in particular to a sealing component which is easy to install a heat exchange tube and an air preheater with the sealing component. Background Art

[0002] Air preheater, as the core heat exchange equipment of boilers widely used in the power, chemical, metallurgical and other industries, plays a vital role in improving the thermal efficiency of boilers. However, the installation of its heat exchange tubes is labor-intensive and time-consuming, and requires high standards from operators; and during the welding process, due to the different thermal expansion coefficients of the base tube and the surface coating of the heat exchange tube when heated, the coating is prone to cracks, resulting in a decrease in the anti-corrosion performance of the heat exchange tube. At the same time, since the heat exchange tubes are generally long, they need to pass through the installation holes reserved on the tube sheet during installation, and the installation holes reserved on the tube sheet are generally small. When the heat exchange tubes pass through the installation holes, the heat exchange tubes are prone to scratches, damaging the anti-corrosion coating, which increases the difficulty of installation. In addition, when replacing the heat exchange tubes, the old heat exchange tubes need to be cut and the welds need to be polished smooth, making replacement very difficult.

[0003] The price of heat exchange tubes made of corrosion-resistant stainless steel is relatively high; if stainless steel composite tubes are used, there is an interface contact thermal resistance between the inner and outer layers, and the heat needs to be transferred through air conduction, radiation, or convection in the contact gap, which cannot achieve efficient heat transfer.

[0004] In the prior art, an anti-corrosion coating is applied on the surface of the base tube, but the coating has poor wear resistance and is fragile and easily prone to collision. It is easy to crack or peel off and is easily damaged by the scouring of fly ash in the flue gas, which seriously affects the anti-corrosion effect and shortens the service life of the heat exchange tube.

[0005] Therefore, developing an air preheater with easy installation of heat exchange tubes, reducing the difficulty of installation of heat exchange tubes, protecting the anti-corrosion coating of the heat exchange tubes, extending the service life of the heat exchange while reducing costs, thereby extending the service life of the air preheater, is a technical problem that needs to be solved urgently. Utility Model Content

[0006] In order to solve the problems existing in the prior art, the utility model provides a seal which is easy to install on a heat exchange tube, so as to solve the current technical problems.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] The utility model provides a seal for easily installing a heat exchange tube, comprising: a proximal end, an arc segment and a tail end, wherein the proximal end and the tail end are connected by the arc segment, the proximal end comprises a proximal end boss, a proximal end outer lip and a proximal end inner lip, and the tail end comprises a tail end boss, a tail end outer lip and a tail end inner lip.

[0009] An air preheater with easy installation of heat exchange tubes includes a seal, a first tube sheet and a second tube sheet. The first tube sheet and the second tube sheet are provided with reserved installation holes in pairs. The seal is arranged in the reserved installation holes and is sleeved on the heat exchange tubes.

[0010] Preferably, a curved lip is also provided on the inner lip at the tail end.

[0011] Preferably, a receiving groove is provided on the inner side of the arc segment.

[0012] Preferably, the heat exchange tube is a stainless steel composite heat-conducting tube, which comprises a bottom base tube, a flexible heat-conducting layer is applied on the base tube, and a stainless steel tube is wrapped around the outer side of the flexible heat-conducting layer.

[0013] Preferably, the heat exchange tube is a rare earth alloy tube, and the rare earth alloy tube comprises a bottom base tube, and the outer side of the base tube is wrapped with a rare earth alloy coating.

[0014] Preferably, the heat exchange tube is a segmented anti-corrosion heat exchange tube, the outer side of the segmented anti-corrosion heat exchange tube is wrapped with a middle layer reinforcement layer, the outer side of one end of the middle layer reinforcement layer is wrapped with a cold end layer, and the outer side of the other end of the middle layer reinforcement layer is wrapped with a heat conductive layer.

[0015] Preferably, the tail end boss and the proximal end boss clamp the first tube sheet or the second tube sheet, and the proximal end outer lip and the tail end outer lip abut against the hole wall of the reserved installation hole.

[0016] Preferably, the tail end boss is provided with a chamfer.

[0017] The beneficial effects of the utility model are: the heat exchange tube is installed on the tube sheet in the form of plugging and unplugging through the sealing member, without welding the tube sheet and the heat exchange tube, which greatly reduces the difficulty of installing the heat exchange tube;

[0018] Use stainless steel composite heat transfer tubes, rare earth alloy tubes or segmented anti-corrosion heat exchange tubes, which have a flat and smooth surface and are easy to maintain a seal with the seals; at the same time, these heat exchange tubes have a small expansion coefficient and expand moderately in the working state. While enhancing the sealing effect between the seals, it will not over-extrude the seals, which is beneficial to protect the seals and extend their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 It is a structural schematic diagram of an air preheater with a seal for easy installation of a heat exchange tube according to an embodiment of the utility model;

[0021] Figure 2This is a schematic diagram of the main structure of a seal that is easy to install on a heat exchange tube according to an embodiment of the utility model;

[0022] Figure 3 It is a schematic cross-sectional structure diagram of a seal member for easily installing a heat exchange tube according to an embodiment of the utility model;

[0023] Figure 4 It is a partial structural schematic diagram of a seal for easily installing a heat exchange tube according to an embodiment of the utility model;

[0024] Figure 5 This is a schematic structural diagram of a segmented anti-corrosion heat exchange tube according to an embodiment of the utility model;

[0025] Figure 6 This is a schematic structural diagram of a rare earth alloy tube according to an embodiment of the utility model;

[0026] Figure 7 This is a schematic structural diagram of another rare earth alloy tube according to an embodiment of the utility model;

[0027] Figure 8 It is a structural schematic diagram of a stainless steel composite heat conducting pipe according to an embodiment of the utility model.

[0028] Description of Reference Numerals

[0029] exist Figure 1-Figure 8 In the figure, the proximal end 1; the arc section 2; the tail end 3; the accommodating groove 4; the proximal end boss 5; the proximal end outer lip 6; the proximal end inner lip 7; the tail end outer lip 8; the tail end boss 9; the tail end inner lip 10; the bent lip 11; the first tube sheet 12; the second tube sheet 13; the sealing element 14; the heat exchange tube 15; the base tube 16; the rare earth alloy coating 17; the sealing layer 18; the flexible heat conductive layer 19; the stainless steel tube 20; the middle layer strengthening layer 21; the cold end layer 22; the heat conductive layer 23. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] A seal for easily installing a heat exchange tube and an air preheater with the seal, comprising a first tube sheet 12 and a second tube sheet 13, wherein the first tube sheet 12 and the second tube sheet 13 are provided with reserved installation holes for installing the heat exchange tube 15 in pairs; and further comprising:

[0032] The seal 14 is structured in three parts, including a proximal end 1, an arc segment 2, and a tail end 3. The proximal end 1 includes a proximal end boss 5, a proximal end outer lip 6, and a proximal end inner lip 7. The tail end 3 includes a tail end boss 9, a tail end outer lip 8, a tail end inner lip 10, and a curved lip 11. The seal 14 is relatively soft and elastic, and can be made of a high temperature resistant and elastic material such as fluororubber.

[0033] The seal 14 is inserted into the reserved installation hole of the tube sheet from the tail end 3, and the tail end boss 9 is provided with a chamfer for easy insertion. After the seal 14 is inserted, the tail end boss 9 and the proximal end boss 5 clamp the tube sheet, and the proximal end outer lip 6 and the tail end outer lip 8 abut against the wall of the reserved installation hole of the tube sheet. A receiving groove 4 is provided on the inner side of the arc section 2, and the receiving groove 4 can be filled with materials such as high-temperature resistant lubricating grease, which is not only convenient for installation and disassembly, but also can block external dust or impurities and improve the sealing effect. The heat exchange tube 15 is also inserted from the tail end 3, and the gap between the inner lip of the seal (including the proximal inner lip 7 and the tail end inner lip 10) and the heat exchange tube 15 is matched, and the minimum diameter of the inner lip of the seal is slightly larger than the outer diameter of the heat exchange tube 15. The minimum diameter of the bent lip 11 of the seal 14 is smaller than the outer diameter of the heat exchange tube 15. As the heat exchange tube 15 is inserted, the bent lip 11 is deformed. Due to the elasticity of the material, the bent lip 11 is tightly abutted against the outer wall of the heat exchange tube 15, thereby achieving effective sealing installation of the heat exchange tube 15. The arc segment 2 forms a buffer with the wall of the reserved installation hole on the tube sheet to adapt to the thermal expansion of the heat exchange tube 15.

[0034] In order to cooperate with the seal 14, the following heat exchange tube 15 is preferably used:

[0035] The stainless steel composite heat-conducting pipe comprises: a bottom base pipe 16, on which a flexible heat-conducting material is applied to form a flexible heat-conducting layer 19, and after the flexible heat-conducting material is applied, a stainless steel pipe 20 is composited on its outer surface, so that the flexible heat-conducting layer 19 is sandwiched between the two rigid materials of stainless steel and base pipe 16.

[0036] The material of the base pipe 16 may be carbon steel pipe, Corden steel pipe, ND steel pipe, etc., or other pipes having high structural strength, high temperature resistance, good thermal conductivity and certain corrosion resistance may be selected.

[0037] The flexible thermally conductive layer 19, the flexible thermally conductive material applied is a modified thermally conductive liquid. These modified thermally conductive liquids are in the form of ointment, which is easy to apply. The modified thermally conductive liquid can be made by adding thermally conductive particles, nanomaterials, metal powders and other materials to the basic thermally conductive liquid; for example, silicone grease or methylphenyl silicone oil is used as the basic thermally conductive liquid, and a single material or a combination of metallic potassium or graphene, graphite, silicon carbide, silver, copper powder and nanopowder is added to make it. It should be noted that in order to avoid electrochemical corrosion between stainless steel and the base tube 16, the basic thermally conductive liquid needs to be a non-conductive liquid, and the added thermally conductive particles have a conductive material that accounts for no more than 40% of the modified thermally conductive liquid.

[0038] The rare earth alloy tube has the following structural components: the bottom layer is a base tube 16, and the outer surface thereof is sprayed with a rare earth alloy material having a self-corrosion potential lower than that of the base tube 16 to form a rare earth alloy coating 17.

[0039] The base pipe 16 can be made of carbon steel pipe, Corden steel pipe, ND steel pipe, etc., or other pipes with high structural strength, high temperature resistance, good thermal conductivity and certain corrosion resistance.

[0040] The material of the rare earth alloy coating 17 can be selected from materials with low self-corrosion potential, such as rare earth aluminum-magnesium alloy, rare earth zinc-aluminum alloy, etc., and is evenly sprayed onto the surface of the base tube 16 by arc spraying. The rare earth alloy wire is melted by an arc, and the molten metal liquid is atomized under the action of high-speed airflow, and is quickly sprayed on the surface of the base tube 16 to form the rare earth alloy coating 17. The metal wire is melted by arc technology, and the droplet temperature of the material reaches more than 6000°C. Under the action of high-pressure airflow, the thermal energy and kinetic energy of the metal particles in the spraying process are relatively high, which is conducive to obtaining better bonding performance and spray layer strength.

[0041] Preferably, according to the above scheme, a sealing layer 18 can be added to the surface of the rare earth alloy coating 17. Since the alloy wire metal liquid after arc melting is still in a granular state after being atomized and sprayed on the surface of the workpiece. The existence of certain pores between them has a certain impact on the use effect and service life of the coating, reducing the corrosion resistance of the coating. The greater the porosity, the worse the corrosion resistance. Therefore, a sealing layer 18 can be sprayed on the surface of the pipe to achieve a better anti-corrosion effect. The sealing layer 18 can be coated with a high-temperature resistant and anti-corrosion coating such as a high-temperature resistant silicone sealing agent or an epoxy glass flake coating.

[0042] The segmented anti-corrosion heat exchange tube includes: the bottom layer is a base tube 16, the outer surface of which is coated with a middle layer strengthening layer 21, one end of the outer surface of the middle layer strengthening layer 21 is sleeved with a cold end layer 22 (for example, a length of 1000-2000mm), and the part other than the cold end layer 22 is coated with a heat conductive layer 23.

[0043] The base pipe 16 can be made of carbon steel pipe, Corden steel pipe, ND steel pipe, etc., or other pipes with high structural strength, high temperature resistance, good thermal conductivity and certain corrosion resistance.

[0044] The middle strengthening layer 21 is used to strengthen the composite material properties, and can be a material that strengthens thermal conductivity or corrosion resistance, and the material selection satisfies at least one of the properties, such as the flexible thermal conductive layer 19 or the rare earth alloy coating 17 in the above two solutions.

[0045] The upper cold end layer 22 is a strong anti-corrosion layer installed at the cold air end of the air preheater. Select metal materials with high corrosion resistance and good wear resistance, such as stainless steel pipes (length 1000-2000mm). Stainless steel has excellent wear resistance and corrosion resistance, which can effectively protect the cold air end of the heat exchange tube 15 and extend the service life of the equipment. At the same time, the stainless steel surface is smooth and has stronger anti-adhesion, which can effectively prevent corrosive substances in the flue gas from adhering to the pipe wall, further enhancing the anti-corrosion effect.

[0046] The upper heat-conducting layer 23 is a coating layer, and a coating with corrosion resistance is selected. For example, the sealing layer 18 uses a silicone sealing agent, which has good fluidity and can be self-leveling, ensuring a good appearance of the heat exchange tube 15. Moreover, the sealing agent generally contains silicone resin and insoluble components, and has good corrosion resistance.

[0047] Preferably, the upper cold end layer 22 and the heat conducting layer 23 have the same thickness and the pipe diameters are uniform.

[0048] The surfaces of the stainless steel composite heat-conducting tubes, rare earth alloy tubes, and segmented anti-corrosion heat exchange tubes 15 are flat and smooth, and are easy to maintain a seal with the seal 14; at the same time, these heat exchange tubes 15 have a small expansion coefficient and expand moderately in the working state. While forming a seal with the installation seal 14, they will not excessively squeeze the installation seal 14, which is beneficial to protecting the installation seal 14 and extending its service life.

[0049] The installation process of the above-mentioned seal 14 and heat exchange tube 15 in the air preheater is as follows:

[0050] The first tube sheet 12 and the second tube sheet 13 on both sides of the air preheater tube box are provided with heat exchange tube installation holes according to design requirements, and the seal 14 is installed on the reserved installation hole of one side of the tube sheet. When installing, it needs to be installed from the outside to the inside of the tube box, so that the tail end 3 of the seal 14 faces inward and the proximal end 1 faces outward.

[0051] The heat exchange tube 15 extends from the reserved installation hole of the tube sheet on the side where the seal 14 is not installed, into the air preheater tube box, and penetrates from the tail end 3 of the installed seal 14, and extends the heat exchange tube 15 out of the tube sheet for a distance. (When the heat exchange tube 15 penetrates the seal 14, some lubricating grease can be applied to reduce friction.)

[0052] The seal 14 is inserted into the reserved installation hole of the tube sheet on the other side. The seal 14 needs to be installed from the outside of the tube box to the inside so that the tail end 3 of the seal 14 faces inward and the proximal end 1 faces outward.

[0053] The heat exchange tube 15 is passed back through the tail end 3 of the seal 14, and the heat exchange tube 15 is extended out of the tube sheet, and the exposed lengths of both sides of the heat exchange tube 15 are adjusted to be consistent.

[0054] After the heat exchange tube 15 is fixed on the air preheater tube box, check whether the installed heat exchange tube 15 is stable to ensure that there is no looseness in each installation position.

[0055] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A seal for easily installing a heat exchange tube, characterized in that: include: A proximal end, an arc segment and a tail end, wherein the proximal end and the tail end are connected by the arc segment, the proximal end comprises a proximal end boss, a proximal end outer lip and a proximal end inner lip, and the tail end comprises a tail end boss, a tail end outer lip and a tail end inner lip.

2. The seal for easily installing a heat exchange tube according to claim 1, characterized in that: A curved lip is also provided on the inner lip of the tail end.

3. The seal for easily installing a heat exchange tube according to claim 1, characterized in that: An accommodating groove is provided on the inner side of the arc segment.

4. An air preheater with a seal for easy installation of heat exchange tubes, characterized in that: The seal comprises the seal as claimed in any one of claims 1 to 3, and further comprises a first tube sheet and a second tube sheet, wherein the first tube sheet and the second tube sheet are provided with reserved installation holes in pairs, the seal is arranged in the reserved installation holes, and the seal is sleeved on the heat exchange tube.

5. The air preheater with a seal for easy installation of heat exchange tubes according to claim 4, characterized in that: The heat exchange tube is a stainless steel composite heat-conducting tube, which comprises a bottom base tube, a flexible heat-conducting layer is coated on the base tube, and a stainless steel tube is wrapped outside the flexible heat-conducting layer.

6. The air preheater with a seal for easy installation of heat exchange tubes according to claim 4, characterized in that: The heat exchange tube is a rare earth alloy tube, and the rare earth alloy tube comprises a base tube as a bottom layer, and the outer side of the base tube is wrapped with a rare earth alloy coating.

7. The air preheater with a seal for easy installation of heat exchange tubes according to claim 4, characterized in that: The heat exchange tube is a segmented anti-corrosion heat exchange tube, the outer side of which is wrapped with a middle strengthening layer, the outer side of one end of the middle strengthening layer is wrapped with a cold end layer, and the outer side of the other end of the middle strengthening layer is wrapped with a heat conducting layer.

8. The air preheater with a seal for easy installation of heat exchange tubes according to claim 4, characterized in that: The tail end boss and the proximal end boss clamp the first tube sheet or the second tube sheet, and the proximal end outer lip and the tail end outer lip abut against the hole wall of the reserved installation hole.

9. The air preheater with a seal for easy installation of heat exchange tubes according to claim 4, characterized in that: The tail end boss is provided with a chamfer.

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