Foam silicon carbide enhanced heat exchange tube type radiant tube burner heat exchanger

Abstract

The utility model relates to the technical field of heat exchange devices, and discloses a foam silicon carbide enhanced heat exchange tube type radiant tube burner heat exchanger which comprises a radiant tube heat exchanger body, foam silicon carbide heat exchange tubes, a heat exchanger tube plate, a smoke outer shell and a smoke inner shell. The device is composed of a foam silicon carbide heat exchange tube, a smoke cover, an air outer shell, a smoke inlet tube, a smoke outlet tube, a preheated air outlet tube and a cold air inlet tube, the foam silicon carbide heat exchange tube comprises a heat exchange base tube, foam silicon carbide is fixedly connected to the outer side of the heat exchange base tube, and heat exchanger tube plates are arranged on the upper side and the lower side of the heat exchange base tube. The foam silicon carbide enhanced heat exchange tube type radiant tube burner heat exchanger has the advantages that the smoke heat exchange effect can be improved by optimizing the structure of the heat exchange base tube, the air preheating temperature is further increased, the smoke exhaust temperature is reduced, the heat efficiency is improved, meanwhile, the production line transformation scheme is simplified by optimizing and adjusting the structure of the heat exchanger, and the equipment investment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange devices, in particular to a method for using an enhanced heat exchange radiant tube burner heat exchanger used in conjunction with a radiant tube burner. Background Art

[0002] In recent years, with the rapid development of the heat treatment field and the continuous advancement of technology, as well as the continuous improvement of the quality and performance requirements of metal products, more and more occasions require the use of radiant tube heating technology. Current research on radiant tube heating technology mainly focuses on thermal efficiency, pollutant emissions, flame control, and combustion control accuracy. Recovery of flue gas waste heat in the radiant tube is the key to improving thermal efficiency. The radiant tube burners currently used in China are all equipped with waste heat recovery heat exchangers. The heat exchanger types include metal double fin type, silicon carbide concave and convex spherical type, tubular heat exchange type, and jet heat exchange type. At the same time, in order to enhance the waste heat recovery effect, the stroke of the heat exchanger has also been gradually lengthened, from a single-stroke heat exchanger installed in the radiant tube to a two-stroke heat exchanger with heat exchange outside the tube, to further increase the air preheating temperature and reduce the exhaust gas temperature.

[0003] Due to the volume limitations of the equipment inside and outside the radiant tube, even if an external double-stroke heat exchanger is used for waste heat recovery, the increased heat exchange area is still limited. Under normal furnace temperature operating conditions, the exhaust gas temperature at the heat exchanger outlet is usually between 500-650°C. In the design of existing heat exchangers, the built-in first-stage heat exchanger mostly adopts finned tube or concave-convex spherical form, while the external second-stage heat exchanger mostly adopts light tube type. The heat exchange on the flue gas side of the second-stage heat exchanger still has a lot of room for improvement. Moreover, there are still a large number of production lines in China that are only equipped with the first-stage heat exchanger structure inside the radiant tube, and the exhaust gas temperature even exceeds 700°C. When a second-stage heat exchanger needs to be added during the energy-saving transformation of the production line, the burner, heat exchanger and intermediate connecting pipelines need to be replaced as a whole, which greatly increases the investment cost of equipment transformation.

[0004] For the existing radiant tube burner heat exchanger structure, it is entirely possible to increase the flue gas heat exchange effect by optimizing the heat exchange base tube structure, further increase the air preheating temperature, reduce the exhaust temperature, and improve thermal efficiency. At the same time, by optimizing and adjusting the heat exchanger structure, the production line transformation plan can be simplified and equipment investment can be reduced. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In response to the shortcomings of the existing technology, the utility model provides a foam silicon carbide reinforced heat exchange tube type radiant tube burner heat exchanger, which has the ability to increase the flue gas heat exchange effect by optimizing the heat exchange base tube structure, further increase the air preheating temperature, reduce the exhaust temperature, and improve thermal efficiency. At the same time, through the optimization and adjustment of the heat exchanger structure, it simplifies the production line transformation plan and reduces equipment investment. It solves the problem that when a secondary heat exchanger needs to be added during the energy-saving transformation of the production line, the burner, heat exchanger and intermediate connecting pipelines need to be replaced as a whole, and the investment cost of equipment transformation increases significantly.

[0007] (2) Technical solution

[0008] The utility model solves the above technical problems with the following technical solutions: A foamed silicon carbide reinforced heat exchange tube type radiant tube burner heat exchanger, comprising a foamed silicon carbide heat exchange tube, a heat exchanger tube sheet, a flue gas outer shell, a flue gas inner shell, a flue gas hood, an air outer shell, a flue gas inlet pipe, a flue gas outlet pipe, a preheated air outlet pipe and a cold air inlet pipe. The foamed silicon carbide heat exchange tube comprises a heat exchange base tube, the outer side of the heat exchange base tube is fixedly connected to foamed silicon carbide, the upper and lower sides of the heat exchange base tube are both provided with heat exchanger tube sheets, the heat exchanger tube sheet is fixedly connected to the heat exchange base tube, and the outer side of the heat exchange base tube is provided with A flue gas outer shell is fixedly connected to the upper and lower heat exchanger tube sheets, a flue gas inner shell is provided inside the heat exchange base tube, a flue gas hood is provided inside the flue gas outer shell, a flue gas outlet pipe is provided at the flue gas hood outlet, an air outer shell is provided outside the heat exchanger tube sheet, the air outer shell is an integral sealed welded structure, a cold air inlet pipe and a preheated air outlet pipe are provided at the lower part of the air outer shell, the flue gas inlet pipe is fixedly connected to the lower heat exchanger tube sheet, and the passing flue gas inlet pipe and the flue gas outlet pipe are continuously sealed and welded.

[0009] The beneficial effects of the utility model are:

[0010] 1. The foamed silicon carbide reinforced heat exchange tube structure design greatly increases the heat exchange area on the flue gas side, effectively improves the heat exchange effect, and the exhaust gas temperature is significantly lower than that of conventional heat exchangers.

[0011] 2. The external flue gas hood structure + adjustable porosity foam silicon carbide structure design can achieve uniform flow of flue gas between the heat exchange tubes, thereby optimizing and improving the heat exchange efficiency on the flue gas side.

[0012] 3. The modular structure design enables the transformation to be completed without replacing the original radiant tube combustion equipment, which greatly reduces the equipment investment cost.

[0013] On the basis of the above technical solution, the present invention can also be improved as follows.

[0014] Furthermore, the foamed silicon carbide heat exchange tube includes a heat exchange base tube and a foamed silicon carbide outer tube structure, wherein the heat exchange base tube adopts a stainless steel precision steel tube with a diameter of 8-10 mm and a wall thickness of 1-1.5 mm. The outside of the heat exchange base tube adopts a columnar foamed silicon carbide structure. According to the length and diameter of the base tube, the foamed silicon carbide is divided into multiple sections, which are respectively inserted into the outer wall of the heat exchange base tube. The foamed silicon carbide can be set to different porosities according to the flue gas volume and flue gas flow rate.

[0015] Furthermore, the heat exchanger tube sheet is divided into an upper tube sheet and a lower tube sheet, which are formed by stainless steel and processed into several circular through holes according to the diameter and distribution of the heat exchange tubes. The upper and lower tube sheets also have processing grooves and bevels for welding with the inner and outer shells.

[0016] Furthermore, the flue gas shell adopts a stainless steel plate welding structure and is fixed to the upper and lower heat exchanger tube sheets by continuous sealing welding.

[0017] Furthermore, the flue gas inner shell is a cylindrical structure, the upper part is continuously sealed and welded with a blind flange, and the lower part is provided with a ball head sealing welding structure, which is integrally sealed and welded with the upper end plate.

[0018] Furthermore, the flue gas hood is arranged on the upper part of the heat exchange tube and is integrally welded with a stainless steel plate. The upper part is sealed and welded to the heat exchanger tube sheet, and the lower part is sealed and welded to the flue gas outer shell. A flue gas outlet hole connected to the flue gas outlet pipe is opened on it.

[0019] Furthermore, the air shell is welded as a whole, and the lower part is continuously sealed and welded with the heat exchanger tube sheet on the lower side to form a preheated air outlet cavity. Four openings are provided on the shell, which are respectively connected to the preheated air outlet pipe, the cold air inlet pipe, the flue gas inlet pipe and the flue gas outlet pipe.

[0020] Furthermore, the flue gas inlet pipe is formed from a stainless steel seamless pipe, penetrates the heat exchanger tube sheet from the air shell and the lower side of the heat exchanger, and is continuously sealed and welded.

[0021] Furthermore, the preheated air outlet pipe and the cold air inlet pipe are formed from stainless steel seamless pipes and are sealed and welded to the air shell. The smoke outlet pipe is formed from seamless steel pipes, penetrates from the air shell and the smoke hood, and is continuously sealed and welded. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the heat exchanger of the utility model;

[0023] Figure 2 Schematic diagram of the planar arrangement of heat exchange tubes and tube sheets;

[0024] Figure 3 Schematic diagram of the structure of foam silicon carbide heat exchange tube;

[0025] Figure 4 This is a schematic diagram of the method for modifying and using the original radiation tube burner.

[0026] In the figure: 1. Heat exchange base tube; 2. Foamed silicon carbide; 3. Heat exchanger tube sheet; 4. Flue gas outer shell; 5. Flue gas inner shell; 6. Flue gas hood; 7. Air outer shell; 8. Flue gas inlet pipe; 9. Preheated air outlet pipe; 10. Cold air inlet pipe; 11. Flue gas outlet pipe; 12. Radiant tube burner with heat exchanger; 13. Radiant tube; 14. Preheated air connecting pipe; 15. Flue gas connecting pipe; 16. Foamed silicon carbide heat exchange tube; 17. Radiant tube heat exchanger. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] The heat exchanger adopts enhanced foam silicon carbide heat exchange tube 16, the heat exchange base tube 1 is made of stainless material, the outer side of the heat exchange base tube 1 adopts foam silicon carbide 2 reinforcement structure to enhance heat exchange, and the heat exchanger tube sheet 3 and the heat exchange base tube 1 are continuously sealed and welded.

[0029] The heat exchange base tube 1 is made of stainless steel precision steel tube with a diameter of 8-10mm and a wall thickness of 1-1.5mm. The exterior of the heat exchange base tube 1 adopts a columnar foam silicon carbide structure. According to the length and diameter of the base tube, the foam silicon carbide 2 is divided into multiple sections with a thickness of 5-10mm, which are respectively inserted into the outer wall of the heat exchange base tube 1. The foam silicon carbide 2 can be set with different porosities according to the flue gas volume and flue gas flow rate to ensure a suitable flow rate on the flue gas side.

[0030] The heat exchanger tube sheet 3 is divided into an upper tube sheet and a lower tube sheet, which are made of stainless steel and are processed into a number of circular through holes according to the diameter and distribution of the heat exchange base tube 1. The upper and lower tube sheets are also provided with processing grooves and grooves for welding with the flue gas inner shell 5 and the flue gas outer shell 4. The foamed silicon carbide heat exchange tubes 16 are arranged in a ring-shaped uniform distribution. The specific arrangement is as follows: Figure 2As shown, there is a suitable spacing between the heat exchange tubes to enhance the heat exchange effect while reducing the flue gas circulation speed. The flue gas outer shell 4 adopts a stainless steel plate welding structure, and is continuously sealed and welded to the upper and lower parts of the heat exchanger tube sheet 3. The flue gas inner shell 5 is a cylindrical structure. The upper part adopts a blind plate flange for continuous sealing welding, and the lower part is provided with a ball head sealing welding structure, and is integrally sealed and welded to the upper part of the heat exchanger tube sheet 3. A flue gas hood 6 is provided on the upper part of the heat exchanger, which is integrally welded with a stainless steel plate. The upper part is sealed and welded to the heat exchanger tube sheet 3, and the lower part is sealed and welded to the flue gas outer shell 4. Sealed welding is performed, and an outlet hole connected to the flue gas outlet pipe 11 is opened on it. The flue gas hood is arranged through an annular structure to ensure that the flue gas flows out evenly from the annular seam at the end of the heat exchanger. The air shell 7 is welded as a whole, and the lower part is continuously sealed and welded with the lower part of the heat exchanger tube plate 3 to form a preheating air outlet cavity. Four openings are set on the shell, which are respectively connected to the preheating air outlet pipe 9, the cold air inlet pipe 10, the flue gas inlet pipe 8 and the flue gas outlet pipe 11. The cooling effect of the external cold air cavity on the flue gas shell 4 further reduces the shell problem and improves the heat exchange efficiency.

[0031] The flue gas inlet pipe 8 is formed by processing a stainless steel seamless steel pipe, penetrates from the air shell 7 and the heat exchanger tube sheet 3, and is continuously sealed and welded. The preheated air outlet pipe 9 and the cold air inlet pipe 10 are formed by processing a stainless steel seamless steel pipe, and are sealed and welded to the air shell 7. The flue gas outlet pipe 11 is formed by processing a seamless steel pipe, penetrates from the air shell 7 and the flue gas hood 6, and is continuously sealed and welded.

[0032] Figure 4 An implementation method for using the radiant tube heat exchanger in conjunction with the radiant tube burner (including the heat exchanger) 12 and the radiant tube 13 is provided.

[0033] Working principle:

[0034] First, the flue gas generated by the combustion of the radiant tube burner (including the heat exchanger) 12 passes through the radiant tube 13, then recovers the waste heat through the primary heat exchanger of the radiant tube burner itself, and is then discharged from the outlet of the radiant tube burner (including the heat exchanger). After the radiant tube heat exchanger is added, the exhaust outlet of the original radiant tube burner (heat exchanger) 12 is connected to the flue gas inlet pipe 8 through the flue gas connecting pipe 15. The flue gas enters the radiant tube heat exchanger through the flue gas inlet pipe 8 for secondary waste heat recovery. The flue gas that has undergone secondary waste heat recovery is discharged into the original exhaust pipe through the flue gas outlet pipe 11.

[0035] Then: the cold air inlet of the original radiant tube burner (including heat exchanger) 12 is connected to the preheated air outlet pipe 9 through the preheated air connecting pipe 14, and the cold air inlet is changed to be connected by the cold air inlet pipe 10 arranged on the radiant tube heat exchanger. The cold air is first preheated through the radiant tube heat exchanger and then sent to the original radiant tube burner (including heat exchanger) 12 for secondary preheating. After the radiant tube heat exchanger is added to the original system, the pressure of the supplied air needs to be increased accordingly, and the exhaust fan suction force needs to be increased to ensure the improvement of the overall heat exchange efficiency.

[0036] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0037] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger, comprising a foamed silicon carbide heat exchange tube (16), a heat exchanger tube sheet (3), a flue gas outer shell (4), a flue gas inner shell (5), a flue gas hood (6), an air outer shell (7), a flue gas inlet pipe (8), a flue gas outlet pipe (11), a preheated air outlet pipe (9), and a cold air inlet pipe (10), characterized in that: The foamed silicon carbide heat exchange tube (16) comprises a heat exchange base tube (1), the outer side of the heat exchange base tube (1) is fixedly connected to the foamed silicon carbide (2), the upper and lower sides of the heat exchange base tube (1) are both provided with heat exchanger tube sheets (3), the heat exchanger tube sheets (3) are fixedly connected to the heat exchange base tube (1), the outer side of the heat exchange base tube (1) is provided with a flue gas outer shell (4) fixedly connected to the upper and lower heat exchanger tube sheets (3), the inner side of the heat exchange base tube (1) is provided with a flue gas inner shell (5) fixedly connected to the upper side heat exchanger tube sheet (3), the flue gas A fume hood (6) is provided inside the outer shell (4), and a fume outlet pipe (11) is provided at the outlet of the fume hood (6). An air shell (7) is provided outside the heat exchanger tube sheet (3). The air shell (7) is an integral sealed welded structure. A cold air inlet pipe (10) and a preheated air outlet pipe (9) are provided at the lower part of the air shell (7). The fume inlet pipe (8) is fixedly connected to the lower side of the heat exchanger tube sheet (3), and continuous sealing welding is performed on the passing fume inlet pipe (8) and the fume outlet pipe (11).

2. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The foamed silicon carbide heat exchange tube (16) comprises a heat exchange base tube (1) and a foamed silicon carbide (2) outer tube structure, wherein the heat exchange base tube (1) is made of a stainless steel precision steel tube with a diameter of 8-10 mm and a wall thickness of 1-1.5 mm. The exterior of the heat exchange base tube (1) is made of a columnar foamed silicon carbide structure. According to the length and diameter of the base tube, the foamed silicon carbide (2) is divided into multiple sections, which are respectively inserted into the outer wall of the heat exchange base tube (1). The foamed silicon carbide (2) can be set to different porosities according to the flue gas volume and flue gas flow rate.

3. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The heat exchanger tube sheet (3) is divided into an upper tube sheet and a lower tube sheet, which are formed by processing stainless steel and processed into a plurality of circular through holes according to the diameter and distribution of the heat exchange tubes. The upper and lower tube sheets are also provided with processing grooves and grooves for welding with the inner and outer shells.

4. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The flue gas outer shell (4) adopts a stainless steel plate welding structure and is fixed to the upper and lower heat exchanger tube sheets (3) through continuous sealing welding.

5. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The flue gas inner shell (5) is a cylindrical structure, the upper part of which is continuously sealed and welded using a blind flange, and the lower part is provided with a ball head sealing welding structure, which is integrally sealed and welded with the upper end plate.

6. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The fume hood (6) is arranged on the upper part of the heat exchange tube and is integrally welded with a stainless steel plate. The upper part is sealed and welded to the heat exchanger tube plate (3), and the lower part is sealed and welded to the fume outer shell (4). A fume outlet hole connected to the fume outlet pipe (11) is opened on the fume hood.

7. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The air shell (7) is integrally welded, and the lower portion is continuously sealed and welded with the lower heat exchanger tube sheet (3) to form a preheating air outlet cavity. Four openings are provided on the shell, which are respectively connected to the preheating air outlet pipe (9), the cold air inlet pipe (10), the smoke inlet pipe (8) and the smoke outlet pipe (11).

8. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The flue gas inlet pipe (8) is formed by processing a stainless steel seamless steel pipe, penetrates the heat exchanger tube plate (3) on the lower side of the air shell and the heat exchanger, and is continuously sealed and welded.

9. The foamed silicon carbide reinforced heat exchange tubular radiant tube burner heat exchanger according to claim 1, characterized in that: The preheated air outlet pipe (9) and the cold air inlet pipe (10) are formed by processing stainless steel seamless steel pipes and are sealed and welded to the air shell (7). The smoke outlet pipe (11) is formed by processing seamless steel pipes and penetrates from the air shell (7) and the smoke hood (6) and is continuously sealed and welded.

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