Economizer and waste heat recovery device

Abstract

The utility model discloses an economizer and a waste heat recovery device, and belongs to the technical field of heat exchange. The economizer comprises a shell and a plurality of heat exchange elements. The heat exchange elements are arranged in the shell and comprise a plurality of heat exchange tube bundles. The at least two heat exchange elements are arranged in the first direction and connected in series. The multiple heat exchange tube bundles of the heat exchange elements are arranged in the third direction at intervals, the at least two heat exchange elements are arranged in the second direction, the multiple heat exchange tube bundles of the at least two heat exchange elements arranged in the second direction are arranged in a crossed mode in the third direction, and the first direction, the second direction and the third direction intersect with one another. When the economizer breaks down, one set of heat exchange elements connected in parallel or in series can be stopped and overhauled, and therefore equipment can be overhauled in the running period of the equipment. By means of the arrangement, the shutdown time can be prevented from being increased, long-period safe operation of the economizer is guaranteed, and meanwhile safety and reliability of the device are guaranteed.

Description

Technical Field

[0001] The present application belongs to the field of heat exchange technology, and specifically relates to an economizer and a waste heat recovery device. Background Art

[0002] In the waste heat recovery device, the economizer is an indispensable device. It is located in the low-temperature area of ​​the flue gas. When the flue gas temperature is low, low-temperature acid dew point corrosion is prone to occur. Therefore, the economizer equipment needs to be frequently inspected, but the current economizer cannot be inspected under normal operation. Utility Model Content

[0003] Purpose of the invention: An embodiment of the present application provides an economizer, aiming to solve the problem that the economizer cannot be repaired under normal operation; another purpose of an embodiment of the present application is to provide a waste heat recovery device.

[0004] Technical solution: The embodiment of the present application provides an economizer, comprising:

[0005] case;

[0006] A plurality of heat exchange elements are arranged in the shell, the heat exchange elements comprising a plurality of heat exchange tube bundles; at least two heat exchange elements are arranged along a first direction and connected in series with each other; the plurality of heat exchange tube bundles of the heat exchange elements are arranged at intervals in a third direction, at least two heat exchange elements are arranged along a second direction, and the plurality of heat exchange tube bundles of at least two heat exchange elements arranged along the second direction are cross-arranged in the third direction, and the first direction, the second direction and the third direction intersect with each other.

[0007] In some embodiments, the economizer includes a tube sheet assembly disposed in a shell, the tube sheet assembly includes multiple tube sheet bodies, and the multiple tube sheet bodies are spaced apart along the second direction; the tube sheet body is provided with a first tube hole, and the heat exchange tube bundle is passed through the first tube holes of the multiple tube sheet bodies.

[0008] In some embodiments, the heat exchange element includes multiple sleeves, the heat exchange tube bundle is inserted into at least one heat exchange tube bundle of the multiple sleeves, the multiple sleeves are correspondingly inserted into multiple first tube holes, the outer wall of the sleeve is connected to the tube sheet assembly, and the inner wall of the sleeve is connected to the heat exchange tube bundle.

[0009] In some embodiments, the tube sheet assembly includes a partition beam, the tube sheet body includes a first tube sheet and a second tube sheet, the partition beam is arranged between the first tube sheet and the second tube sheet, the first tube sheet and the second tube sheet are arranged along a first direction, at least one heat exchange element is arranged on the first tube sheet, at least one heat exchange element is arranged on the second tube sheet, and the heat exchange element arranged on the first tube sheet and the heat exchange element arranged on the second tube sheet in the first direction are connected in series.

[0010] In some embodiments, the economizer includes a first expansion joint, and the tube sheet assembly is connected to the shell through the first expansion joint;

[0011] The economizer includes a second expansion joint, the first tube sheet is connected to the partition beam via the second expansion joint, and the second tube sheet is connected to the partition beam via the second expansion joint.

[0012] In some embodiments, the heat exchange element comprises an inlet and an outlet, and the outlet of the heat exchange tube bundle of one heat exchange element is communicated with the inlet of the heat exchange tube bundle of another heat exchange element adjacent in the first direction.

[0013] In some embodiments, the heat exchange element further includes a first header and a second header, the first header is in communication with the inlet, and the second header is in communication with the outlet.

[0014] In some embodiments, the economizer includes an elbow box, the elbow box is arranged on both sides of the shell along the second direction, the first header and the second header are arranged in the elbow box, and the heat exchange tube bundle extends into the elbow box.

[0015] In some embodiments, the economizer includes a third expansion joint, and the first header is connected to the elbow box through the third expansion joint;

[0016] The economizer includes a fourth expansion joint, and the second header is connected to the elbow box through the fourth expansion joint.

[0017] In some embodiments, the economizer includes a third expansion joint, and the first header is connected to the elbow box through the third expansion joint;

[0018] The economizer comprises a header cover, and the second header is connected to the elbow box through the header cover.

[0019] In some embodiments, the economizer includes a manhole pipe and a manhole cover. The manhole pipe is arranged on a side of the elbow box away from the heat exchange tube bundle, and the manhole cover is movably covered on the manhole pipe.

[0020] In some embodiments, the economizer includes a hanging device, which includes a hanging beam and a pipe clamp. The end of the hanging beam close to the shell is connected to the shell, and the end of the hanging beam away from the shell is connected to the pipe clamp. The pipe clamp is provided with multiple second tube holes, and the heat exchange tube bundle is passed through the multiple second tube holes.

[0021] Accordingly, an embodiment of the present application provides a waste heat recovery device, including an economizer as described in any of the above embodiments.

[0022] Beneficial effect: The economizer of the embodiment of the present application includes a shell and a plurality of heat exchange elements. The plurality of heat exchange elements are arranged in the shell, and the heat exchange elements include a plurality of heat exchange tube bundles. At least two heat exchange elements are arranged along a first direction and connected in series with each other. The plurality of heat exchange tube bundles of the heat exchange elements are arranged at intervals in a third direction, at least two heat exchange elements are arranged along a second direction, and the plurality of heat exchange tube bundles of at least two heat exchange elements arranged along the second direction are cross-arranged in the third direction, and the first direction, the second direction, and the third direction intersect with each other. When a fault occurs in the economizer, one group of the series heat exchange elements or one group of the parallel heat exchange elements is stopped and repaired, thereby realizing the maintenance of the equipment during the operation of the equipment. With such a configuration, the increase of downtime can be avoided, the long-term safe operation of the economizer can be ensured, and the safety and reliability of the device can be ensured.

[0023] The waste heat recovery device of the embodiment of the present application includes the above-mentioned economizer, so the waste heat recovery device can have all the technical features and beneficial effects of the above-mentioned economizer, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 is a cross-sectional view of an economizer according to an embodiment of the present application;

[0026] Figure 2 is a structural schematic diagram of an economizer according to an embodiment of the present application;

[0027] Figure 3 is a structural schematic diagram of an economizer according to another embodiment of the present application;

[0028] Figure 4 is a structural schematic diagram of a tube sheet assembly according to an embodiment of the present application;

[0029] Figure 5 It is a structural schematic diagram of a tube sheet assembly and a heat exchange element in an embodiment of the present application;

[0030] Figure 6 It is a schematic diagram of the structure of the hanging device of an embodiment of the present application.

[0031] Figure numerals: 1, shell; 2, heat exchange element; 3, first heat exchange element; 4, second heat exchange element; 5, third heat exchange element; 6, fourth heat exchange element; 7, tube sheet assembly; 8, first expansion joint; 9, second expansion joint; 10, elbow box; 11, third expansion joint; 12, header cover; 13, manhole pipe; 14, manhole cover; 15, hanging device; 16, header positioning plate; 20, heat exchange tube bundle; 21, sleeve; 22, inlet; 23, outlet; 24, first header; 25, second header; 70, tube sheet body; 71, first pipe hole; 72, partition beam; 150, hanging beam; 151, pipe clamp; 152, second pipe hole; 700, first tube sheet; 701, second tube sheet. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0033] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined. In the description of this application, "vertical" means completely vertical at 90° or almost completely vertical, for example, an angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel, for example, an angle within 10° of completely parallel is considered parallel.

[0034] Economizer is an indispensable device in the waste heat recovery device. It is located in the low-temperature area of ​​the flue gas. When the flue gas temperature is low, low-temperature acid dew point corrosion is prone to occur. Economizer equipment needs to be frequently inspected. The current economizer cannot be inspected and repaired under normal operation.

[0035] In view of this, an embodiment of the present application provides an economizer and a waste heat recovery device, which aims to solve the problem that the economizer cannot be repaired under normal operation. The economizer of the embodiment of the present application includes a shell and a plurality of heat exchange elements. The plurality of heat exchange elements are arranged in the shell, and the heat exchange elements include a plurality of heat exchange tube bundles. At least two heat exchange elements are arranged along the first direction and connected in series with each other. The plurality of heat exchange tube bundles of the heat exchange elements are arranged at intervals in the third direction, at least two heat exchange elements are arranged along the second direction, and the plurality of heat exchange tube bundles of at least two heat exchange elements arranged along the second direction are cross-arranged in the third direction, and the first direction, the second direction, and the third direction intersect with each other. When a fault occurs in the economizer, one group of the parallel heat exchange elements can be stopped and repaired, so as to realize the maintenance of the equipment during the operation of the equipment. With such a configuration, the increase of downtime can be avoided, the long-term safe operation of the economizer can be ensured, and the safety and reliability of the device can be ensured.

[0036] The economizer and waste heat recovery device of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0037] refer to Figures 1 to 6 , an embodiment of the present application provides an economizer, comprising a shell 1 and a plurality of heat exchange elements 2. The plurality of heat exchange elements 2 are arranged in the shell 1, and the heat exchange elements 2 include a plurality of heat exchange tube bundles 20. At least two heat exchange elements 2 are arranged along a first direction X1 and are connected in series with each other. The plurality of heat exchange tube bundles 20 of the heat exchange elements 2 are arranged at intervals in a third direction X3, at least two heat exchange elements 2 are arranged along a second direction X2, and the plurality of heat exchange tube bundles 20 of at least two heat exchange elements 2 arranged along the second direction X2 are cross-arranged in the third direction X3, and the first direction X1, the second direction X2, and the third direction X3 intersect with each other. In an embodiment of the present application, the first direction X1 and the second direction X2 are perpendicular, such as Figure 1 The third direction X3 is perpendicular to the first direction X1 and the second direction X2, as shown in FIG. Figure 2 As shown. The economizer is used to recover the heat energy in the high-temperature flue gas generated during the combustion process to heat the water or other media to be preheated. Thereby improving the energy utilization efficiency. The series-connected heat exchange elements 2 allow heat to be transferred and exchanged between the flue gas and the water for multiple times, thereby improving the heat exchange efficiency. When a failure occurs in the economizer, one group of the series-connected heat exchange elements 2 or one group of the parallel-connected heat exchange elements 2 is stopped and repaired, thereby realizing the maintenance of the equipment during the operation of the equipment. Such a setting can avoid the increase of downtime, ensure the long-term safe operation of the economizer, and at the same time ensure the safety and reliability of the device.

[0038] In an embodiment of the present application, the economizer includes a first heat exchange element 3, a second heat exchange element 4, a third heat exchange element 5 and a fourth heat exchange element 6, the first heat exchange element 3 and the second heat exchange element 4 are arranged along a first direction X1, and the first heat exchange element 3 and the second heat exchange element 4 are connected in series, the third heat exchange element 5 and the fourth heat exchange element 6 are arranged along the first direction X1, and the third heat exchange element 5 and the fourth heat exchange element 6 are connected in series, as shown in FIG. Figure 3 As shown. The series-connected heat exchange elements 2 allow the flue gas and water to transfer and exchange heat multiple times, thereby improving the heat exchange efficiency. The first heat exchange element 3 and the third heat exchange element 5 are arranged side by side in the second direction X2, and the heat exchange tube bundle 20 of the first heat exchange element 3 and the heat exchange tube bundle 20 of the third heat exchange element 5 are arranged crosswise in the third direction X3, as shown. Figure 2 The second heat exchange element 4 and the fourth heat exchange element 6 are arranged side by side in the second direction X2, and the heat exchange tube bundle 20 of the second heat exchange element 4 and the heat exchange tube bundle 20 of the fourth heat exchange element 6 are arranged crosswise in the third direction X3, as shown in FIG. Figure 2 As shown. When a failure occurs in the economizer, one group of the series heat exchange elements 2 or one group of the parallel heat exchange elements 2 is stopped and repaired, so that the equipment can be repaired during operation. Such an arrangement can avoid the increase of downtime, ensure the long-term safe operation of the economizer, and at the same time ensure the safety and reliability of the device.

[0039] exist Figure 4 and Figure 5 In the illustrated embodiment, the economizer includes a tube sheet assembly 7, which is arranged in the shell 1. The tube sheet assembly 7 includes a plurality of tube sheet bodies 70, and the plurality of tube sheet bodies 70 are arranged at intervals along the second direction X2. The tube sheet body 70 is provided with a first tube hole 71, and the heat exchange tube bundle 20 is penetrated through the first tube holes 71 of the plurality of tube sheet bodies 70. The heat exchange element 2 includes a plurality of sleeves 21, and the heat exchange tube bundle 20 is penetrated through at least one heat exchange tube bundle 20 of the plurality of sleeves 21. The plurality of sleeves 21 are correspondingly penetrated through the plurality of first tube holes 71. The outer wall of the sleeve 21 is connected to the tube sheet assembly 7, and the inner wall of the sleeve 21 is connected to the heat exchange tube bundle 20. In the embodiment of the present application, the heat exchange tube bundle 20 is penetrated through the sleeve 21 and welded to the sleeve 21, and the sleeve 21 is penetrated through the first tube hole 71 and welded to the tube sheet assembly 7. Such an arrangement can reduce the risk of corrosion caused by smoke leakage at the joint between the heat exchange tube bundle 20 and the tube sheet assembly 7, and can also reduce the risk of weld cracking caused by expansion of the heat exchange tube bundle 20.

[0040] exist Figure 1In the illustrated embodiment, the tube sheet assembly 7 includes a partition beam 72, a first tube sheet 700 and a second tube sheet 701. The partition beam 72 is disposed between the first tube sheet 700 and the second tube sheet 701. The first tube sheet 700 and the second tube sheet 701 are arranged along the first direction X1. At least one heat exchange element 2 is disposed on the first tube sheet 700, and at least one heat exchange element 2 is disposed on the second tube sheet 701. The heat exchange element 2 disposed on the first tube sheet 700 and the heat exchange element 2 disposed on the second tube sheet 701 in the first direction X1 are connected in series. The tube sheet assembly 7 is divided into the first tube sheet 700 and the second tube sheet 701, so that independent thermal expansion can be achieved. Since the first tube sheet 700 and the second tube sheet 701 are respectively connected to the partition beam, when the heat exchange element 2 expands due to heat, the first tube sheet 700 and the second tube sheet 701 can independently expand thermally without interfering with each other. This helps to reduce stress concentration and deformation, and improve the reliability and durability of the economizer. Specifically, in the embodiment of the present application, the tube sheet assembly 7 is a flexible tube sheet, and the thickness of the tube sheet assembly 7 is thin, which is easy to produce a large deformation when it is heated and expanded. By providing the first tube sheet 700 and the second tube sheet 701, the stress of the entire tube sheet assembly 7 can be evenly distributed, the stress concentration can be reduced, and the deformation or rupture of the tube sheet assembly 7 due to excessive stress caused by local thermal expansion can be avoided.

[0041] exist Figure 1 In the illustrated embodiment, the economizer includes a first expansion joint 8, and the tube sheet assembly 7 is connected to the shell 1 through the first expansion joint 8. The first expansion joint 8 is used to absorb the thermal expansion of the heat exchange tube bundle 20 and the tube sheet assembly 7 and provide a certain degree of deformation space, thereby ensuring the sealing between the tube sheet assembly 7 and the shell 1 and improving the heat recovery efficiency. In other embodiments, the economizer includes a second expansion joint 9, and the first tube sheet 700 is connected to the partition beam 72 through the second expansion joint 9, and the second tube sheet 701 is connected to the partition beam 72 through the second expansion joint 9. The first expansion joint 8 is used to absorb the thermal expansion of the heat exchange tube bundle 20, the partition beam 72 and the tube sheet assembly 7 and provide a certain degree of deformation space, thereby ensuring the sealing between the tube sheet assembly 7 and the partition beam 72 and improving the heat recovery efficiency.

[0042] exist Figure 1 In the illustrated embodiment, the heat exchange element 2 includes an inlet 22 and an outlet 23, and the outlet 23 of the heat exchange tube bundle 20 of one heat exchange element 2 is connected to the inlet 22 of the heat exchange tube bundle 20 of another heat exchange element 2 adjacent in the first direction X1. The heat exchange element 2 also includes a first header 24 and a second header 25, the first header 24 is connected to the inlet 22, and the second header 25 is connected to the outlet 23. The first header 24 and the second header 25 are symmetrically arranged in the second direction X2.

[0043] exist Figure 2In the illustrated embodiment, the economizer includes an elbow box 10 , which is disposed on both sides of the shell 1 along the second direction X2 , a first header 24 and a second header 25 are disposed in the elbow box 10 , and a heat exchange tube bundle 20 extends into the elbow box 10 .

[0044] exist Figure 1 In the illustrated embodiment, the economizer further includes a plurality of header positioning plates 16, one end of which is connected to the elbow box 10, and the other end of which is connected to the first header 24 or the second header 25. The header positioning plates 16 are used to fix the first header 24 and the second header 25.

[0045] In some embodiments, the economizer includes a third expansion joint 11, and the first header 24 is connected to the elbow box 10 through the third expansion joint 11. Figure 1 The economizer includes a fourth expansion joint (not shown), and the second header 25 is connected to the elbow box 10 through the fourth expansion joint. In this way, the third expansion joint 11 can absorb the thermal expansion between the first header 24 and the elbow box 10, and the fourth expansion joint can absorb the thermal expansion between the second header 25 and the elbow box 10.

[0046] In other embodiments, the economizer includes a third expansion joint 11, and the first header 24 is connected to the elbow box 10 through the third expansion joint 11. The third expansion joint 11 can absorb the thermal expansion between the first header 24 and the elbow box 10. The economizer includes a header cover 12, and the second header 25 is connected to the elbow box 10 through the header cover 12. Figure 1 In this arrangement, the header cover 12 is welded on the second header 25, that is, the end cover side, and the header cover 12 can absorb the thermal expansion between the second header 25 and the elbow box 10, which is lower in cost than setting the third expansion joint 11.

[0047] exist Figure 1 In the embodiment shown, the economizer includes a manhole pipe 13 and a manhole cover 14. The manhole pipe 13 is arranged on a side of the elbow box 10 away from the heat exchange tube bundle 20, and the manhole cover 14 is movably covered on the manhole pipe 13. Figure 1 In the illustrated embodiment, there are four manhole pipes 13, which are correspondingly arranged on the side of the four elbow boxes 10 away from the heat exchange tube bundle 20. When any one of the first heat exchange element 3, the second heat exchange element 4, the third heat exchange element 5 and the fourth heat exchange element 6 fails, online maintenance can be performed through the manhole pipe 13.

[0048] exist Figure 6In the illustrated embodiment, the economizer includes a hanging device 15, which includes a hanging beam 150 and a pipe clamp 151. The end of the hanging beam 150 close to the shell 1 is connected to the shell 1, and the end of the hanging beam 150 away from the shell 1 is connected to the pipe clamp 151. The pipe clamp 151 is provided with a plurality of second tube holes 152, and the heat exchange tube bundle 20 is penetrated through the plurality of second tube holes 152. The hanging beam 150 provides a stable support and fixation by being connected to the shell 1. The design of the hanging beam 150 and the pipe clamp 151 facilitates the installation and maintenance of the economizer. By adjusting the position of the hanging beam 150, the heat exchange tube bundle 20 can be effectively positioned and suspended. To replace or maintain the heat exchange tube bundle 20, it is only necessary to remove it from the second tube holes 152, which is simple and convenient.

[0049] The embodiment of the present application also provides a waste heat recovery device, including an economizer as described in any of the above embodiments. It is intended to solve the problem that the economizer cannot be repaired during normal operation. When a fault occurs in the economizer, one group of the parallel heat exchange elements 2 can be stopped and repaired, so that the equipment can be repaired during the operation of the equipment. Such a setting can avoid the increase of downtime, ensure the long-term safe operation of the economizer, and at the same time ensure the safety and reliability of the device.

[0050] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0051] The above is a detailed introduction to an economizer and a waste heat recovery device provided in the embodiments of the present application, and the principles and implementation methods of the present application are explained by applying specific examples. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A coal economizer, characterized in that: include: Housing (1); A plurality of heat exchange elements (2) are arranged in the shell (1), the heat exchange elements (2) comprising a plurality of heat exchange tube bundles (20); at least two of the heat exchange elements (2) are arranged along a first direction and are connected in series with each other; the plurality of heat exchange tube bundles (20) of the heat exchange elements (2) are arranged at intervals in a third direction, at least two of the heat exchange elements (2) are arranged along a second direction, and the plurality of heat exchange tube bundles (20) of at least two of the heat exchange elements (2) arranged along the second direction are arranged crosswise in the third direction, and the first direction, the second direction and the third direction intersect with each other.

2. The economizer according to claim 1, characterized in that: The economizer comprises a tube sheet assembly (7) arranged in the shell (1), the tube sheet assembly (7) comprising a plurality of tube sheet bodies (70), the plurality of tube sheet bodies (70) being arranged at intervals along the second direction; the tube sheet body (70) being provided with a first tube hole, the heat exchange tube bundle (20) being passed through the first tube hole of the plurality of tube sheet bodies (70).

3. The economizer according to claim 2, characterized in that: The heat exchange element (2) comprises a plurality of sleeves (21), the heat exchange tube bundle (20) is penetrated through at least one of the plurality of sleeves (21), the plurality of sleeves (21) are correspondingly penetrated through the plurality of first tube holes, the outer wall of the sleeve (21) is connected to the tube sheet assembly (7), and the inner wall of the sleeve (21) is connected to the heat exchange tube bundle (20).

4. The economizer according to claim 2, characterized in that: The tube sheet assembly (7) comprises a partition beam (72), the tube sheet body (70) comprises a first tube sheet (700) and a second tube sheet (701), the partition beam (72) is arranged between the first tube sheet (700) and the second tube sheet (701), the first tube sheet (700) and the second tube sheet (701) are arranged along a first direction, at least one of the heat exchange elements (2) is arranged on the first tube sheet (700), at least one of the heat exchange elements (2) is arranged on the second tube sheet (701), and the heat exchange elements (2) arranged on the first tube sheet (700) and the heat exchange elements (2) arranged on the second tube sheet (701) in the first direction are connected in series.

5. The economizer according to claim 4, characterized in that: The economizer comprises a first expansion joint (8), and the tube sheet assembly (7) is connected to the shell (1) via the first expansion joint (8); The economizer includes a second expansion joint (9), the first tube sheet (700) is connected to the partition beam (72) via the second expansion joint (9), and the second tube sheet (701) is connected to the partition beam (72) via the second expansion joint (9).

6. The economizer according to claim 1, characterized in that: The heat exchange element (2) comprises an inlet (22) and an outlet (23), and the outlet (23) of the heat exchange tube bundle (20) of one heat exchange element (2) is connected to the inlet (22) of the heat exchange tube bundle (20) of one heat exchange element (2) adjacent in the first direction.

7. The economizer according to claim 6, characterized in that: The heat exchange element (2) further comprises a first header (24) and a second header (25), wherein the first header (24) is in communication with the inlet (22), and the second header (25) is in communication with the outlet (23).

8. The economizer according to claim 7, characterized in that: The economizer comprises an elbow box (10), the elbow box (10) being arranged on both sides of the shell (1) along the second direction, the first header (24) and the second header (25) being arranged in the elbow box (10), and the heat exchange tube bundle (20) extending into the elbow box (10).

9. The economizer according to claim 8, characterized in that: The economizer comprises a third expansion joint (11), and the first header (24) is connected to the elbow box (10) via the third expansion joint (11); The economizer comprises a fourth expansion joint, and the second header (25) is connected to the elbow box (10) via the fourth expansion joint.

10. The economizer according to claim 8, characterized in that: The economizer comprises a third expansion joint (11), and the first header (24) is connected to the elbow box (10) via the third expansion joint (11); The economizer comprises a header cover (12), and the second header (25) is connected to the elbow box (10) through the header cover (12).

11. The economizer according to claim 8, characterized in that: The economizer comprises a manhole pipe (13) and a manhole cover (14); the manhole pipe (13) is arranged on a side of the elbow box (10) away from the heat exchange tube bundle (20); and the manhole cover (14) is movably covered on the manhole pipe (13).

12. The economizer according to claim 1, characterized in that: The economizer comprises a hanging device (15), wherein the hanging device (15) comprises a hanging beam (150) and a pipe clamp (151), wherein one end of the hanging beam (150) close to the shell (1) is connected to the shell (1), and one end of the hanging beam (150) away from the shell (1) is connected to the pipe clamp (151), and the pipe clamp (151) is provided with a plurality of second pipe holes (152), and the heat exchange tube bundle (20) is penetrated through the plurality of second pipe holes (152).

13. A waste heat recovery device, characterized in that: It comprises the economizer as described in any one of claims 1 to 12 above.

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