Tubular air preheater

Abstract

The invention discloses a tubular air preheater which comprises a steam inlet tube box, a condensed water outlet tube box, a tube bundle assembly, a shell pass barrel, a shell pass air inlet and a shell pass air outlet. The inlet tube box is connected with the shell pass cylinder through a flange, and the shell pass cylinder is connected with the outlet tube box through a flange; the tube bundle assembly is arranged in the shell pass cylinder; and a shell pass air inlet and a shell pass air outlet are respectively formed in the shell pass barrel. A tube pass medium is high-temperature steam, a shell pass medium is air, normal-temperature air is preheated to a certain temperature through the high-temperature steam through heat exchange of the heat exchange tubes, and the defects that an existing tubular preheater is inconvenient to disassemble, not easy to clean and the like are overcome.

Description

Technical Field

[0001] The present invention relates to the field of air preheating, and particularly to a tubular air preheater. Background Art

[0002] An air preheater is a type of heat exchanger and a key device in the waste heat recovery system in the petrochemical field. Its function is to preheat air to a certain temperature using boiler flue gas or high-temperature steam.

[0003] Preheating air with high-temperature steam generated through waste heat recovery reduces heat loss and increases the heat recovery and utilization efficiency. A shell-and-tube air preheater includes a shell and a heat exchanger tube bundle. The heat exchanger tube bundle is used to convey steam, and the channel between the tube bundle and the shell is used to convey air. Since there are inevitably some impurities in the air and the outer periphery of the heat exchange tubes is not completely smooth, after using for a period of time, it is necessary to clean the outer periphery of the heat exchange tube bundle. Since the tube bundle is usually fixed inside the shell, the previous cleaning of the outer periphery of the tube bundle mainly adopted the method of backwashing or laid a coating with a relatively high surface finish on the outer peripheral surface of the heat exchange tube bundle. The method of backwashing requires isolating the equipment separately and supporting a backwashing pipeline system, which is inconvenient to use; laying a coating with a relatively high surface finish will reduce the heat exchange efficiency of the heat exchange tube bundle, thereby reducing the heating effect of the air. At the same time, this method is only applicable to the structural type where the outer wall of the heat exchange tube is a smooth tube.

[0004] Chinese Patent CN219328115U discloses a tubular air preheater. A coating is provided on the outer periphery of the heat exchange tube, and a heat conducting member is provided outside the heat exchange pipeline with the coating. While preventing the adhesion of flue gas dust, the heat transfer efficiency is increased through the heat conducting member. However, the additional heat conducting member in this patent affects the circulation of the medium outside the tube bundle and increases the manufacturing difficulty. The coating on the outer periphery of the heat exchange tube bundle only prolongs the time of dust adhesion and cannot completely avoid dust adhesion. Summary of the Invention

[0005] The purpose of the present invention is to provide a tubular air preheater, where the tube-side medium is high-temperature steam and the shell-side medium is air. Through the heat exchange of the heat exchange tubes, the normal-temperature air is preheated to a certain temperature by the high-temperature steam, and at the same time, it is convenient to disassemble, so as to solve the deficiencies of the existing tubular preheater such as inconvenient disassembly and difficult cleaning.

[0006] The technical solution of the present invention is as follows: A tubular air preheater includes a steam inlet header, a condensate outlet header, a tube bundle assembly, a shell-side cylinder, a shell-side air inlet, and a shell-side air outlet; the inlet header is connected to the shell-side cylinder through a flange, and the shell-side cylinder is connected to the outlet header through a flange; the tube bundle assembly is arranged inside the shell-side cylinder; the shell-side air inlet and the shell-side air outlet are respectively opened on the shell-side cylinder.

[0007] Preferably, the steam inlet header includes a steam inlet flange, an inlet header head, an inlet header cylinder, an inlet header flange, and an impact baffle. The steam inlet flange, the inlet header head, the inlet header cylinder, and the inlet header flange are sequentially connected by welding, and the impact baffle is welded inside the inlet header head.

[0008] Preferably, the condensate outlet header includes a condensate outlet flange, an outlet header head, an outlet header cylinder, and an outlet header flange. The condensate outlet flange, the outlet header head, the outlet header cylinder, and the outlet header flange are sequentially connected by welding.

[0009] Preferably, the tube bundle assembly includes a fixed tube sheet, a floating tube sheet, a tube bundle, fins, and a wind baffle. The fins are arranged on the outside of the tube bundle, and the fixed tube sheet and the floating tube sheet are respectively arranged at both ends of the tube bundle; the wind baffle is arranged on the outside of the tube bundle and the fins, and the wind baffle is welded to the fixed tube sheet to prevent air from escaping from the tube bundle range through the gaps between the heat exchange tubes when air enters, thus improving the heat exchange efficiency.

[0010] Preferably, the shell side cylinder includes an upper flange, a cylinder body, and a lower flange; the shell side air inlet includes an inlet flange, an inlet nozzle, and an inlet cone section; the shell side air outlet includes an outlet flange, an outlet nozzle, and an outlet cone section.

[0011] Preferably, the present invention further includes an ear component, which is fixedly connected to the outside of the shell side cylinder, and the ear component includes two lug supports arranged symmetrically.

[0012] Preferably, the fixed tube sheet in the tube bundle assembly is a clamping type tube sheet, which is clamped by the inlet header flange and the upper flange, and the sealing surface is sealed with a flat gasket.

[0013] Preferably, sealing packing is filled between the floating tube sheet in the tube bundle assembly and the lower flange and the outlet header flange. It can expand freely while ensuring the sealing performance. During operation, the upper tube sheet is fixed and the lower tube sheet can expand and contract freely, so no thermal stress will be generated.

[0014] When the outer periphery of the tube bundle needs to be cleaned, first remove the condensate outlet header, take out the packing between the lower tube sheet and the lower flange, then remove the steam inlet header, and draw out the tube bundle assembly from above. Clean the tube bundle assembly at a suitable place. The cleaning method can be a physical method or a chemical method. After the tube bundle is cleaned and installed in place, it can be put into use.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. Through the heat exchange between air and steam, the steam is used to preheat the air, improving the utilization efficiency of waste heat.

[0017] 2. By adding fins outside the heat exchange tubes, the heat exchange area is increased and space is saved.

[0018] 3. The detachable tube bundle can achieve regular tube bundle cleaning, improving the service life of the air preheater. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the front view of the structure of a tubular air preheater according to the present invention;

[0020] Figure 2 It is the top view of the structure of a tubular air preheater according to the present invention;

[0021] Figure 3 It is the schematic diagram of the tube bundle of a tubular air preheater according to the present invention;

[0022] Figure 4 It is the detailed drawing of the steam inlet header of a tubular air preheater according to the present invention;

[0023] Figure 5 It is the detailed drawing of the condensate outlet header of a tubular air preheater according to the present invention;

[0024] Figure 6 It is the detailed drawing of the shell, nozzles and lugs of a tubular air preheater according to the present invention;

[0025] In the figure: 1. Steam inlet header; 2. Condensate outlet header; 3. Tube bundle assembly; 4. Shell side cylinder; 5. Shell side air inlet; 6. Shell side air outlet; 7. Lug assembly; 8. Sealing packing; 101. Steam inlet flange; 102. Inlet header head; 103. Inlet header cylinder; 104. Inlet header flange; 105. Impingement baffle; 201. Condensate outlet flange; 202. Outlet header head; 203. Outlet header cylinder; 204. Outlet header flange; 301. Fixed tube sheet; 302. Floating tube sheet; 303. Tube bundle; 304. Fins; 305. Wind baffle; 401. Upper flange; 402. Cylinder; 403. Lower flange; 501. Inlet flange; 502. Inlet nozzle; 503. Inlet cone section; 601. Outlet flange; 602. Outlet nozzle; 603. Outlet cone section. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions of the present invention will be described below with reference to the accompanying drawings.

[0027] As Figure 1 shown, a tubular air preheater includes a steam inlet header 1, a condensate outlet header 2, a tube bundle assembly 3, a shell side cylinder 4, a shell side air inlet 5, a shell side air outlet 6, and a lug assembly 7.

[0028] As Figure 4The shown steam inlet header 1 is welded by an inlet header head 102, an inlet header cylinder 103, and an inlet header flange 104. A steam inlet flange 101 is provided in the middle of the inlet header head 102, and an impact baffle 105 is arranged directly below it, which can prevent the steam from directly scouring the heat exchange tubes.

[0029] As Figure 5 shown, the condensate outlet header 2 is welded by an outlet header head 202, an outlet header cylinder 203, and an outlet header flange 204. A condensate outlet flange 201 is provided in the middle of the outlet header head 202, and the condensate can be collected and discharged.

[0030] As Figure 2 and Figure 3 shown, the tube bundle assembly 3 is composed of a fixed tube sheet 301, a floating tube sheet 302, a tube bundle 303, fins 304, and a wind baffle 305; the tube bundle 303 is a heat exchange tube with a smooth outer wall, and fins 304 are arranged on the outer periphery to increase the heat transfer area and improve the heat transfer efficiency; the tube bundle 303 is connected to the fixed tube sheet 301 and the floating tube sheet 302 by a combined connection method of welding and strength expansion, and wind baffles 305 are arranged on both sides of the tube bundle, and the wind baffles 305 are welded to the fixed tube sheet 301.

[0031] As Figure 6 shown, the shell-side cylinder 4 is composed of an upper flange 401, a cylinder 402, and a lower flange 403. A shell-side air inlet 5 and a shell-side air outlet 6 are provided on the cylinder 402. The shell-side air inlet 5 is welded in sequence by an inlet flange 501, an inlet nozzle 502, and an inlet cone section 503. The shell-side air outlet 6 is welded in sequence by an outlet flange 601, an outlet nozzle 602, and an outlet cone section 603. A support ear assembly 7 composed of two support ears is symmetrically provided on the cylinder 402.

[0032] The shell-side cylinder 4 is supported above the framework by the support ear assembly 7. The tube bundle assembly 3 is inserted into the shell-side cylinder 4 from above. The fixed tube sheet 301 is supported above the upper flange 401. The steam inlet header 1 is supported above the fixed tube sheet 301 through the inlet header flange 104. The inlet header flange 104 and the upper flange 401 are connected by bolts and nuts. The lower flange 403 and the outlet header flange 204 are connected together by bolts and nuts. A sealing filler 8 is placed between the floating tube sheet 302 and the lower flange 403 and the outlet header flange 204. During normal operation, the sealing between the tube and the shell and the sealing between the tube-shell side and the outside are achieved by compressing the sealing filler 8.

[0033] The above are only typical examples of the present invention and do not impose any formal restrictions on the present invention. Any person skilled in the relevant art, without departing from the technical solution of the present invention, any changes or modifications made using the above technical content should be regarded as equivalent examples of equivalent changes. All content that does not depart from the technical solution of the present invention, any equivalent changes made to the above examples based on the technical essence of the present invention, fall within the scope of the technical solution of the present invention.

Claims

1. A tubular air preheater, characterized in that: It includes a steam inlet header, a condensate outlet header, a tube bundle assembly, a shell side cylinder, a shell side air inlet, and a shell side air outlet; the inlet header is connected to the shell side cylinder through a flange, and the shell side cylinder is connected to the outlet header through a flange; the tube bundle assembly is arranged inside the shell side cylinder; the shell side air inlet and the shell side air outlet are respectively opened on the shell side cylinder.

2. The tubular air preheater according to claim 1, wherein: It further includes an ear component, the ear component is fixedly connected to the outside of the shell side cylinder, and the ear component includes two lug supports arranged symmetrically.

3. A tubular air preheater according to claim 1, characterized in that: The steam inlet header includes a steam inlet flange, an inlet header head, an inlet header cylinder, an inlet header flange, and an impact baffle. The steam inlet flange, the inlet header head, the inlet header cylinder, and the inlet header flange are sequentially connected by welding, and the impact baffle is welded inside the inlet header head.

4. A tubular air preheater according to claim 1, characterized in that: The condensate outlet header includes a condensate outlet flange, an outlet header head, an outlet header cylinder, and an outlet header flange. The condensate outlet flange, the outlet header head, the outlet header cylinder, and the outlet header flange are sequentially connected by welding.

5. A tubular air preheater according to claim 1, wherein: The tube bundle assembly includes a fixed tube sheet, a floating tube sheet, a tube bundle, fins, and a wind baffle. The fins are arranged on the outside of the tube bundle, and the fixed tube sheet and the floating tube sheet are respectively arranged at both ends of the tube bundle; the wind baffle is arranged on the outside of the tube bundle and the fins, and the wind baffle is welded to the fixed tube sheet.

6. The tubular air preheater according to claim 1, characterized in that: The shell side cylinder includes an upper flange, a cylinder body, and a lower flange; the shell side air inlet includes an inlet flange, an inlet nozzle, and an inlet cone section; the shell side air outlet includes an outlet flange, an outlet nozzle, and an outlet cone section.

7. The tubular air preheater according to claim 5, characterized in that: The fixed tube sheet is a clamping type tube sheet, which is clamped by the inlet header flange and the upper flange, and the sealing surface is sealed with a flat gasket.

8. A tubular air preheater according to claim 5, characterized in that: Sealing packing is filled between the floating tube sheet, the lower flange, and the outlet header flange.

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