A nickel-based alloy heat exchanger based on weld overlay tube sheet

Abstract

This utility model discloses a nickel-based alloy heat exchanger based on a weld overlay tube sheet, including a heat exchanger shell. A detachable nickel-based alloy heat exchanger body is installed inside the heat exchanger shell. A heat exchanger fixing assembly for fixing the nickel-based alloy heat exchanger body is installed at the top of the heat exchanger shell, corresponding to the position of the nickel-based alloy heat exchanger body. A heat exchanger defrosting assembly for heating and defrosting the nickel-based alloy heat exchanger body is installed at the bottom of the heat exchanger shell, corresponding to the position of the nickel-based alloy heat exchanger body. Mounting tracks for placing the nickel-based alloy heat exchanger body are provided on both sides of the heat exchanger shell. This utility model allows for easy disassembly and assembly, facilitating maintenance and repair, by sliding the nickel-based alloy heat exchanger body onto the mounting tracks of the heat exchanger shell and securing it with a fixing cover. The bottom heating element enables rapid heating and defrosting, and a reversible motor drives a circulating fan to move back and forth, enhancing hot air flow and improving the defrosting effect.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a nickel-based alloy heat exchanger based on a weld overlay tube sheet. Background Technology

[0002] In the field of heat exchangers, heat exchangers of different materials and structures are widely used in various industrial and civil applications to meet diverse heat exchange requirements. For example, Chinese Patent CN220380324U discloses a titanium alloy heat exchanger, which includes a heat exchanger body, a titanium alloy support, an electrolytic cell, a power supply, and inert electrodes. By placing the titanium alloy support in an electrolytic cell containing electrolyte, connecting the heat exchanger body to the negative terminal of the power supply, and immersing the inert electrodes in the electrolyte and connecting them to the positive terminal of the power supply, the technical problem of current heat exchangers being corroded by liquid media is solved using the electrolysis principle. This effectively extends the service life of the heat exchanger and has significant advantages in corrosion prevention.

[0003] However, in practical applications, heat exchangers not only face corrosion problems but are also prone to frosting when operating in low-temperature environments. Frosting severely affects the heat exchanger's efficiency, increases energy consumption, and may even cause the heat exchanger to malfunction. While the aforementioned titanium alloy heat exchanger technology solves the corrosion problem, it lacks a convenient and effective defrosting function. Many existing heat exchangers suffer from numerous inconveniences in defrosting, such as limited defrosting methods, poor effectiveness, or complex and cumbersome defrosting devices, failing to meet the demands of efficient and convenient defrosting in actual production and daily life. Utility Model Content

[0004] The purpose of this invention is to provide a nickel-based alloy heat exchanger based on a weld overlay tube sheet. The main body of the nickel-based alloy heat exchanger is slidably installed on the installation slide of the heat exchanger shell and fixed with a fixing cover, which makes disassembly and assembly convenient and easy to maintain and repair. The bottom heating element can quickly heat and defrost, and the forward and reverse motor drives the circulating fan to move back and forth, which enhances the flow of hot air and improves the defrosting effect.

[0005] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0006] A nickel-based alloy heat exchanger based on weld overlay tube sheet, comprising:

[0007] The heat exchanger shell contains a detachable nickel-based alloy heat exchanger body. A heat exchanger fixing assembly for securing the nickel-based alloy heat exchanger body is installed at the top of the heat exchanger shell, corresponding to the position of the nickel-based alloy heat exchanger body. A heat exchanger defrosting assembly for heating and defrosting the nickel-based alloy heat exchanger body is installed at the bottom of the heat exchanger shell, corresponding to the position of the nickel-based alloy heat exchanger body. The nickel-based alloy heat exchanger body includes a weld overlay tube sheet. The base material of the weld overlay tube sheet is low-carbon steel or low-alloy steel. A 3-5 mm thick nickel-based alloy layer is welded over the connection surface between the tube sheet and the heat exchange tubes and the medium contact area. The nickel-based alloy layer material is selected from Inconel 625 or Hastelloy C276.

[0008] The aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet has mounting tracks on both sides of the heat exchanger shell for placing the main body of the nickel-based alloy heat exchanger.

[0009] In the aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet, a support spring is fixedly connected to the bottom of the inner wall of the mounting slide, and an elastic support block is fixedly connected to the top of the support spring.

[0010] The aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet, wherein the heat exchanger fixing assembly includes a fixing cover that matches the heat exchanger shell, and the fixing cover is fixedly connected to the top of the heat exchanger shell by the mounting bolts.

[0011] In the aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet, the bottom of the fixed cover is also fixedly connected to an abutment spring, the bottom of the abutment spring is fixedly connected to an abutment plate, and the bottom of the abutment plate abuts against the top of the nickel-based alloy heat exchanger body.

[0012] The aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet includes a heat exchanger defrosting assembly comprising heating elements installed at the bottom of the heat exchanger housing, and a reversible motor fixedly connected to the bottom side of the heat exchanger housing. A threaded shaft is fixedly connected to the output shaft of the reversible motor, and a threaded sleeve is threadedly connected to the threaded shaft. A circulation fan is installed on the top of the threaded sleeve.

[0013] In the aforementioned nickel-based alloy heat exchanger based on weld overlay tube sheet, a limiting slide rod is fixedly connected to the inner wall of the heat exchanger shell, a limiting sleeve is slidably connected to the limiting slide rod, and the top of the limiting sleeve is fixedly connected to the bottom of the threaded sleeve.

[0014] This utility model has at least the following beneficial effects:

[0015] 1. This utility model realizes a nickel-based alloy heat exchanger based on a weld overlay tube sheet. The main body of the nickel-based alloy heat exchanger is slidably installed on the installation slide of the heat exchanger shell and fixed with a fixing cover, which is convenient for disassembly and assembly and easy for maintenance and repair. The bottom heating plate can quickly heat and defrost. The forward and reverse motor drives the circulating fan to move back and forth, which enhances the flow of hot air and improves the defrosting effect. The support spring and elastic support block in the installation slide, and the abutment spring and abutment plate at the bottom of the fixing cover provide stable support and fixation for the main body of the heat exchanger. The limiting slide rod and limiting slide sleeve on the inner wall accurately limit the movement of the threaded sleeve, ensuring the smooth operation of the circulating fan, improving the reliability and service life of the equipment, effectively solving the problem of inconvenient defrosting of existing heat exchangers, with high practical value and broad prospects for promotion.

[0016] 2. Convenient Assembly and Disassembly: This invention slides the nickel-based alloy heat exchanger body onto the mounting track on the heat exchanger shell and secures it with a fixing cover. This design makes the installation and disassembly of the nickel-based alloy heat exchanger body extremely simple. Operators can quickly complete the assembly and disassembly of the heat exchanger body without complicated tools or cumbersome steps. This not only greatly improves work efficiency but also facilitates regular maintenance, inspection, and replacement of the heat exchanger body, reducing equipment maintenance costs and ease of use.

[0017] 3. High-efficiency defrosting: Heating fins are installed at the bottom of the heat exchanger shell. When frost forms on the heat exchanger, the heating fins quickly generate heat to defrost the nickel-based alloy heat exchanger body installed inside the shell. This direct heating method can quickly melt the frost layer, effectively solving the problem of frost formation on the heat exchanger and restoring its normal heat exchange performance.

[0018] 4. Enhanced Hot Air Flow: A reversible motor drives the threaded shaft to rotate, which, under the action of the threaded sleeve, causes the circulating fan on the sleeve to move back and forth continuously. The reciprocating motion of the circulating fan increases the flow of hot air inside the heat exchanger shell, allowing the heat generated by the heating elements to be more evenly distributed inside the heat exchanger. This further improves the defrosting effect on the nickel-based alloy heat exchanger body, ensuring a more thorough and efficient defrosting process.

[0019] 5. Reasonable and Stable Structure: The support springs and elastic blocks installed at the bottom of the inner wall of the mounting slide provide stable support and cushioning for the main body of the nickel-based alloy heat exchanger, reducing vibration and shaking during operation and improving the stability and reliability of the equipment. Simultaneously, the abutment springs and abutment plates at the bottom of the fixing cover further enhance the fixing effect on the main body of the nickel-based alloy heat exchanger, ensuring stable operation under various working conditions.

[0020] 6. Limit Protection: The limit sliding rod fixed on the inner wall of the heat exchanger shell and the limit sliding sleeve that are slidably connected play a precise limiting role in the movement of the threaded sleeve, preventing the threaded sleeve from deviating or jamming during the movement, ensuring that the circulating fan can move back and forth smoothly along the predetermined trajectory, thereby ensuring the normal operation of the entire defrosting system and improving the reliability and service life of the equipment. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of the nickel-based alloy heat exchanger based on the weld overlay tube sheet of this utility model;

[0023] Figure 2 This is a schematic cross-sectional view of the nickel-based alloy heat exchanger based on weld overlay tube sheet according to this utility model.

[0024] Figure 3 This utility model Figure 2 A magnified schematic diagram of the partial structure at point A in the middle;

[0025] Figure 4 This is a schematic diagram of the heat exchanger fixing assembly in the nickel-based alloy heat exchanger based on weld overlay tube sheet of this utility model.

[0026] Explanation of icon numbers:

[0027] 1. Heat exchanger shell; 2. Nickel-based alloy heat exchanger body; 3. Heat exchanger fixing assembly; 4. Heat exchanger defrosting assembly;

[0028] 201. Install the slide rail;

[0029] 202. Elastic support block; 2021. Support spring;

[0030] 301. Fixing cover; 3011. Mounting bolts;

[0031] 302, Abutment Spring; 3021, Abutment Plate;

[0032] 401. Reverse-rotating motor; 4011. Threaded shaft; 4012. Threaded sleeve; 4013. Circulating fan;

[0033] 402, Limiting slide bar; 4021, Limiting slide sleeve; 41, Heating element. Detailed Implementation

[0034] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0035] Please refer to Figures 1 to 4 As shown, an embodiment of this utility model provides a nickel-based alloy heat exchanger based on a weld overlay tube sheet, comprising: a heat exchanger shell 1, a detachable nickel-based alloy heat exchanger body 2 installed inside the heat exchanger shell 1, a heat exchanger fixing assembly 3 for fixing the nickel-based alloy heat exchanger body 2 installed at the top of the heat exchanger shell 1 and corresponding to the position of the nickel-based alloy heat exchanger body 2, and a heat exchanger defrosting assembly 4 for heating and defrosting the nickel-based alloy heat exchanger body 2 installed at the bottom of the heat exchanger shell 1 and corresponding to the position of the nickel-based alloy heat exchanger body 2; the nickel-based alloy heat exchanger body 2 includes a weld overlay tube sheet, the base material of the weld overlay tube sheet is low carbon steel or low alloy steel, and a 3-5 mm thick nickel-based alloy layer is welded over the connection surface between the tube sheet and the heat exchange tube and the medium contact area, the nickel-based alloy layer material being Inconel 625 or Hastelloy C276.

[0036] By adopting the above technical solutions, the heat exchanger body can be disassembled, is easy to fix, and has a high-efficiency defrosting function, which improves the ease of use and performance of the heat exchanger.

[0037] The tube sheet substrate is made of low-carbon steel or low-alloy steel, which reduces costs while ensuring basic strength. A 3-5mm thick Inconel 625 or Hastelloy C276 nickel-based alloy layer is welded to the tube sheet and the heat exchange tube connection surface and the medium contact area. This layer can withstand acid, alkali, high temperature and high pressure media corrosion, solving the problem of easy corrosion and leakage of traditional tube sheets. The tube sheet is formed by tungsten inert gas welding (TIG). It is preheated at 200-300℃ before welding and stress-relief annealed at 600-650℃ after welding (holding for 2-3 hours). The weld layer is tested by PT or UT and the bonding strength is ≥200MPa. This avoids defects such as pores and cracks in the weld layer, further enhancing the structural stability and service life of the tube sheet. At the same time, it matches the material of the nickel-based alloy heat exchanger body 2, improving the overall corrosion resistance consistency.

[0038] To facilitate the installation and positioning of the nickel-based alloy heat exchanger body 2, in this embodiment, mounting slides 201 for placing the nickel-based alloy heat exchanger body 2 are provided on both sides of the heat exchanger shell 1. The mounting slides 201 provide a precise installation position for the nickel-based alloy heat exchanger body 2, making the installation process simpler and faster. The heat exchanger body can be quickly placed in the designated position, improving installation efficiency, and also ensuring the stable placement of the heat exchanger body inside the heat exchanger shell 1.

[0039] To provide cushioning support for the nickel-based alloy heat exchanger body 2 placed in the installation slide 201 and reduce the impact of vibration, in this embodiment: a support spring 2021 is fixedly connected to the bottom of the inner wall of the installation slide 201, and an elastic support block 202 is fixedly connected to the top of the support spring 2021. The combined design of the support spring 2021 and the elastic support block 202 can provide a cushioning effect during the installation of the nickel-based alloy heat exchanger body 2, avoiding damage to the heat exchanger body due to installation impact. At the same time, during the operation of the heat exchanger, it can effectively absorb vibration energy, reduce the shaking of the heat exchanger body, improve the stability and reliability of the equipment, and extend the service life of the equipment.

[0040] To ensure a secure fixation of the nickel-based alloy heat exchanger body 2 and facilitate disassembly and assembly, in this embodiment, the heat exchanger fixing assembly 3 includes a fixing cover 301 that matches the heat exchanger shell 1. The fixing cover 301 is fixedly connected to the top of the heat exchanger shell 1 by mounting bolts 3011. The cooperation between the fixing cover 301 and the mounting bolts 3011 firmly fixes the nickel-based alloy heat exchanger body 2 inside the heat exchanger shell 1, preventing displacement during operation. Moreover, this fixing method is simple to operate; simply tightening or loosening the mounting bolts 3011 completes the installation and removal of the fixing cover 301, greatly facilitating the maintenance and replacement of the heat exchanger body.

[0041] To further enhance the fixing effect on the nickel-based alloy heat exchanger body 2 and ensure its stable operation, in this embodiment: a retaining spring 302 is fixedly connected to the bottom of the fixing cover 301, and a retaining plate 3021 is fixedly connected to the bottom of the retaining spring 302. The bottom of the retaining plate 3021 abuts against the top of the nickel-based alloy heat exchanger body 2. The retaining spring 302 and the retaining plate 3021 provide upward elastic pressure to the nickel-based alloy heat exchanger body 2, which, together with the supporting effect of the mounting slide 201, forms a two-way fixing force, making the heat exchanger body more securely installed in the heat exchanger shell 1. This elastic fixing method can also adapt to a certain degree of thermal expansion and contraction, avoiding damage caused by excessive stress between the heat exchanger body and the shell due to temperature changes.

[0042] To achieve efficient heating and defrosting of the nickel-based alloy heat exchanger body 2, in this embodiment: the heat exchanger defrosting assembly 4 includes a heating element 41 installed at the bottom of the heat exchanger housing 1. The assembly also includes a reversible motor 401 fixedly connected to the bottom side of the heat exchanger housing 1. A threaded shaft 4011 is fixedly connected to the output shaft of the motor 401, and a threaded sleeve 4012 is threaded onto the threaded shaft 4011. A circulating fan 4013 is installed on the top of the threaded sleeve 4012. The heating element 41 can directly heat the inside of the heat exchanger housing 1, quickly melting the frost layer on the surface of the nickel-based alloy heat exchanger body 2, thus achieving efficient defrosting. The reversible motor 401 drives the threaded shaft 4011 to rotate, causing the threaded sleeve 4012 to reciprocate linearly along the threaded shaft 4011. The circulating fan 4013 installed on the top of the threaded sleeve 4012 moves reciprocally accordingly, accelerating the flow of hot air inside the heat exchanger housing 1, making the heating more uniform, further improving the defrosting effect, and shortening the defrosting time.

[0043] To ensure the stable reciprocating movement of the threaded sleeve 4012 along the threaded shaft 4011 and to ensure the normal operation of the circulating fan 4013, in this embodiment: a limiting slide rod 402 is fixedly connected to the inner wall of the heat exchanger housing 1, and a limiting sleeve 4021 is slidably connected to the limiting slide rod 402. The top of the limiting sleeve 4021 is fixedly connected to the bottom of the threaded sleeve 4012. The combined structure of the limiting slide rod 402 and the limiting sleeve 4021 provides precise guidance and limiting for the movement of the threaded sleeve 4012, preventing the threaded sleeve 4012 from rotating or deviating during the rotation of the threaded shaft 4011, and ensuring that the threaded sleeve 4012 can only perform linear reciprocating motion along the threaded shaft 4011. This allows the circulating fan 4013 to move smoothly along a predetermined trajectory, ensuring the normal operation of the heat exchanger defrosting assembly 4 and improving the reliability and stability of the equipment.

[0044] Specifically, in this embodiment, the weld overlay tube sheet is formed by tungsten inert gas welding (TIG). The substrate preheating temperature before welding is 200-300℃. After welding, stress relief annealing is performed at 600-650℃ and held for 2-3 hours. The weld overlay layer needs to pass penetrant testing (PT) or ultrasonic testing (UT), and the bonding strength is not less than 200MPa.

[0045] The weld overlay tube sheet has heat exchange tube holes with a wall roughness ≤ Ra1.6μm. After the heat exchange tubes are inserted into the tube holes, they are connected by an expansion welding method of "mechanical expansion joint + fillet weld welding". The welding wire is matched with the nickel-based alloy material of the weld overlay layer. The weld overlay tube sheet and the flange connection surface of the heat exchanger shell 1 have an annular sealing groove, and a metal spiral wound gasket made of nickel-based alloy strip and graphite material is embedded in the groove.

[0046] The weld overlay tube plate has sliders on both sides that match the mounting slide 201. The slider surface is chrome plated (thickness 0.05-0.1mm). The bottom of the slider and the contact area with the elastic support block 202 are arc-shaped. A PT100 temperature sensor is attached to the surface of the weld overlay tube plate, and a medium discharge port with a shut-off valve is provided at the bottom. It is also connected to the main shell of the nickel-based alloy heat exchanger by high-temperature alloy bolt flanges.

[0047] Using the above technical solution, the wall roughness of the heat exchange tube holes on the weld overlay tube sheet is ≤Ra1.6μm. After the heat exchange tubes are inserted, they are connected by a combination of mechanical expansion and fillet weld. The welding wire is matched with the nickel-based alloy material of the weld overlay layer. The double seal improves the connection sealing performance between the heat exchange tubes and the weld overlay tube sheet, preventing media leakage. At the same time, an annular sealing groove is opened on the flange connection surface between the weld overlay tube sheet and the heat exchanger shell 1, and a metal spiral wound gasket made of nickel-based alloy strip and graphite material is embedded to adapt to high temperature and high pressure conditions, further enhance the sealing performance, and avoid media leakage at the connection between the shell and the tube sheet.

[0048] The weld overlay tube plate is equipped with sliders on both sides that match the mounting slide 201. The slider surface is chrome plated (thickness 0.05-0.1mm) to reduce the friction coefficient between the slider and the mounting slide 201, which facilitates the smooth sliding of the nickel-based alloy heat exchanger body 2 (including the weld overlay tube plate) along the mounting slide 201 and improves the ease of disassembly and assembly. In addition, the contact area between the bottom of the slider and the elastic support block 202 is an arc-shaped surface, which increases the contact area and allows the buffering force of the support spring 2021 to be evenly transmitted to the weld overlay tube plate, reducing the vibration and impact of the weld overlay tube plate and the nickel-based alloy heat exchanger body 2 during installation and operation, avoiding damage to the weld overlay layer and protecting the structural integrity of the components.

[0049] A PT100 temperature sensor is attached to the surface of the weld overlay tube sheet to monitor the tube sheet temperature in real time. This sensor is linked to the heat exchanger defrosting assembly 4, automatically activating the heating element 41 (including auxiliary heating elements) when the temperature drops below 5°C and shutting off when the temperature reaches 15°C, precisely controlling the defrosting process and avoiding energy waste. The bottom of the weld overlay tube sheet has a media discharge port with a shut-off valve, allowing residual media between the tube sheet and heat exchange tubes to be drained before maintenance, preventing media leakage and contamination or safety hazards during maintenance. Furthermore, the weld overlay tube sheet is connected to the nickel-based alloy heat exchanger body using high-temperature alloy bolt flanges. The weld overlay tube sheet can be replaced individually by removing the bolts, eliminating the need to disassemble the entire nickel-based alloy heat exchanger body 2, reducing maintenance costs and shortening equipment downtime.

[0050] The working principle of this utility model is as follows:

[0051] First, the nickel-based alloy heat exchanger body 2 is slid into the designated position along the mounting tracks 201 on both sides of the heat exchanger shell 1. The support spring 2021 and elastic support block 202 at the bottom of the inner wall of the mounting track 201 provide buffer support for the heat exchanger body. Then, the fixing cover 301 is installed on the top of the heat exchanger shell 1 by mounting bolts 3011. The abutment spring 302 and abutment plate 3021 at the bottom of the fixing cover 301 apply an upward elastic pressure to the nickel-based alloy heat exchanger body 2, which, together with the support of the mounting track 201, achieves a stable fixation of the heat exchanger body, facilitating subsequent disassembly and assembly operations.

[0052] When defrosting of the nickel-based alloy heat exchanger body 2 is required, the heating element 41 at the bottom of the heat exchanger shell 1 is activated, and the heating element 41 begins to heat the interior of the heat exchanger shell 1. Simultaneously, the reversible motor 401, fixedly connected to the bottom side of the heat exchanger shell 1, is activated. The reversible motor 401 drives the threaded shaft 4011 to rotate, and under the action of the thread, the threaded sleeve 4012 reciprocates linearly along the threaded shaft 4011. Since the bottom of the threaded sleeve 4012 is slidably connected to the limiting slide rod 402 fixed on the inner wall of the heat exchanger shell 1 via a limiting slide sleeve 4021, the stability of the threaded sleeve 4012's movement is ensured. The circulating fan 4013 at the top of the threaded sleeve 4012 reciprocates along with the threaded sleeve 4012, accelerating the flow of hot air inside the heat exchanger shell 1, making the heat generated by the heating element 41 more evenly distributed around the heat exchanger, thereby quickly and efficiently melting the frost layer on the surface of the nickel-based alloy heat exchanger body 2, improving the defrosting effect, and ensuring the normal operation of the heat exchanger.

[0053] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A nickel-based alloy heat exchanger based on a clad tube sheet, comprising a heat exchanger shell (1), characterized in that, A detachable nickel-based alloy heat exchanger body (2) is installed inside the heat exchanger shell (1). A heat exchanger fixing assembly (3) for fixing the nickel-based alloy heat exchanger body (2) is installed at the top of the heat exchanger shell (1) and at the position corresponding to the nickel-based alloy heat exchanger body (2). A heat exchanger defrosting assembly (4) for heating and defrosting the nickel-based alloy heat exchanger body (2) is installed at the bottom of the heat exchanger shell (1) and at the position corresponding to the nickel-based alloy heat exchanger body (2). The nickel-based alloy heat exchanger body (2) includes a weld overlay tube sheet. The base material of the weld overlay tube sheet is low carbon steel or low alloy steel. A nickel-based alloy layer with a thickness of 3-5 mm is welded on the connection surface between the tube sheet and the heat exchange tube and the medium contact area.

2. A nickel-based alloy heat exchanger based on a cladded tube sheet as claimed in claim 1, wherein: The heat exchanger shell (1) has mounting slides (201) on both sides for placing the nickel-based alloy heat exchanger body (2).

3. A nickel-based alloy heat exchanger based on a weld overlay tube sheet according to claim 2, characterized in that: A support spring (2021) is fixedly connected to the bottom of the inner wall of the mounting slide (201), and an elastic support block (202) is fixedly connected to the top of the support spring (2021).

4. A nickel-based alloy heat exchanger based on a weld overlay tube sheet according to claim 3, characterized in that: The heat exchanger fixing assembly (3) includes a fixing cover (301) that matches the heat exchanger housing (1), and the fixing cover (301) is fixedly connected to the top of the heat exchanger housing (1) by the mounting bolts (3011).

5. A nickel-based alloy heat exchanger based on a weld overlay tube sheet according to claim 4, characterized in that: The bottom of the fixed cover (301) is also fixedly connected to an abutment spring (302), and the bottom of the abutment spring (302) is fixedly connected to an abutment plate (3021), and the bottom of the abutment plate (3021) abuts against the top of the nickel-based alloy heat exchanger body (2).

6. A nickel-based alloy heat exchanger based on a weld overlay tube sheet according to claim 5, characterized in that: The heat exchanger defrosting assembly (4) includes a heating element (41) installed at the bottom of the heat exchanger housing (1). The heat exchanger defrosting assembly (4) also includes a reversible motor (401) fixedly connected to the bottom side of the heat exchanger housing (1). A threaded shaft (4011) is fixedly connected to the output shaft of the reversible motor (401). A threaded sleeve (4012) is threadedly connected to the threaded shaft (4011). A circulating fan (4013) is installed on the top of the threaded sleeve (4012).

7. A nickel-based alloy heat exchanger based on a weld overlay tube sheet according to claim 5, characterized in that: A limiting slide rod (402) is fixedly connected to the inner wall of the heat exchanger shell (1), and a limiting sleeve (4021) is slidably connected to the limiting slide rod (402), with the top of the limiting sleeve (4021) fixedly connected to the bottom of the threaded sleeve (4012).

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