A heat exchange tube welding preheating device

Abstract

The application relates to a heat exchange pipe welding preheating device and relates to the technical field of heat exchange pipe processing.The device comprises a fixing ring and a plurality of heaters, the heaters are detachably installed on the fixing ring through supports, the plurality of heaters are uniformly distributed along the inner periphery of the fixing ring, the heaters are correspondingly arranged with pipe heads of the heat exchange pipes, and the fixing ring is arranged on the inner side of a pipe plate of the heat exchange pipes. The application uniformly distributes the heaters on the inner periphery of the fixing ring, ensures that the heaters can uniformly heat the pipe head parts of the heat exchange pipes, the uniform heating helps to reduce thermal stress, avoids cracks or other welding defects caused by excessive temperature difference in the welding process, and improves the quality and reliability of the welding joint. Moreover, the detachable installation of the heaters through the supports enables the heaters to be easily removed after preheating, avoids the interference of the heaters on the pipe heads in the welding process, and ensures that the welding operation is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of heat exchange pipe processing technology, in particular to a heat exchange pipe welding preheating device. BACKGROUND

[0002] As a key heat exchange equipment, heat exchangers are widely used in petroleum refining, chemical industry, pharmaceutical industry and other industrial fields. Its main function is to effectively transfer heat, improve energy efficiency and save energy. In these industries, heat exchangers often need to withstand very complex working conditions, such as high temperature, high pressure, corrosion and other environments, so the structure, material and process of the equipment are required to be higher, especially in the welding process of heat exchanger.

[0003] In the manufacturing process of heat exchanger, welding technology is the key link to ensure the structural strength and durability of the equipment. Especially in some special applications, the welding quality of the heat exchange pipe head is crucial to the safety and service life of the equipment. In the welding process, in order to ensure the welding quality and avoid equipment failure caused by welding defects, preheating treatment is usually needed for the welding part. Through preheating treatment, cold cracks, hot cracks and other defects that may occur in the welding process can be reduced, and the toughness, strength and durability of the welded joint can be improved.

[0004] However, with the increasing demand for welding quality, especially in the manufacturing process of large heat exchangers such as waste heat boilers, the preheating temperature before welding gradually increases, which puts higher requirements on the welding heating device. At present, the existing preheating devices mostly rely on traditional heating methods, such as electric blanket, heating furnace or flame heating, etc., but these methods often have the problems of uneven heating, low thermal efficiency, complex operation, etc. In addition, with the increase of welding temperature, how to ensure the efficiency and accuracy of the preheating process without affecting the normal welding operation is still a technical problem to be solved in the industry.

[0005] Therefore, it is urgent to develop a new preheating device that can provide uniform and stable heating effect under high temperature preheating conditions and does not affect the later welding work, in order to meet the growing demand for high temperature preheating, and thus ensure the welding quality and long-term stable operation of heat exchanger. INVENTION CONTENTS

[0006] In order to provide uniform and stable heating effect under high temperature preheating conditions and not affect the later welding work, the present application provides a heat exchange pipe welding preheating device.

[0007] The heat exchange pipe welding preheating device provided by the present application adopts the following technical scheme:

[0008] The application discloses a heat exchange pipe welding preheating device which comprises a fixing ring and a plurality of heaters.

[0009] By adopting the technical scheme, the heaters are evenly distributed on the inner periphery of the fixing ring, so that the heaters can uniformly heat the pipe head part of the heat exchange pipe, the uniform heating helps to reduce thermal stress and avoid cracks or other welding defects caused by excessive temperature difference in the welding process, and the quality and reliability of the welded joint are improved; and the design that the heaters are detachably installed on the support makes the heaters easy to be removed after preheating, avoids interference of the heaters on the pipe head in the welding process, ensures that the welding operation is not affected, and the heaters are easy to maintain or replace, and the service life of the equipment is prolonged.

[0010] In a specific implementable scheme, a temperature control unit is further included, and the temperature control unit is used for controlling the temperature of the heaters.

[0011] By adopting the technical scheme, after the temperature control unit is introduced, the temperature of the heaters can be adjusted and controlled, the temperature control unit monitors the working state of the heaters in real time, and automatically adjusts the heating power according to the data of the temperature sensor, so that the heaters are maintained in the required preheating temperature range, cracks or other welding defects caused by excessive temperature fluctuation are avoided, and the operation convenience and welding quality are improved.

[0012] In a specific implementable scheme, the heaters are respectively independently configured with the temperature control unit or at most two heaters share one temperature control unit.

[0013] By adopting the technical scheme, the independent temperature control provided by the independent configuration of the temperature control unit is more accurate and suitable for occasions requiring strict temperature control; and the shared temperature control unit is suitable for a plurality of heaters with similar temperature requirements, reduces the hardware cost, can reduce the complexity of the control system, and improves the working efficiency.

[0014] In a specific implementable scheme, the support comprises an inclined part and two parallel flat parts, the inclined part is connected between the two flat parts, one of the flat parts is detachably connected with the heater, and the other flat part is detachably connected with the fixing ring.

[0015] By adopting the technical scheme, the support design has good flexibility and practicability, the stable installation and adjustment of the heater are ensured through the inclined part and the detachable connection, the installation, maintenance and replacement of the heater are more convenient, and the long-term operation efficiency and economy of the device are improved.

[0016] In a specific implementation, the inclined part is arranged at an obtuse angle with the straight part.

[0017] By adopting the technical scheme, the support can support the heater at a more effective angle, a more suitable contact surface and connection mode are provided, the stability of the device in actual use is enhanced, and flexible installation angle and adjustment space are provided.

[0018] In a specific implementation, the fixing ring is composed of a plurality of arc-shaped plates, and adjacent two arc-shaped plates are fixed through a tension screw.

[0019] By adopting the technical scheme, the fixing ring composed of a plurality of arc-shaped plates is fixed through a tension screw, compared with a single ring structure, the number or shape of the arc-shaped plates can be adjusted to adapt to different diameters or size requirements, so that the fixing ring can meet the use requirements of various specifications or environments; and the arc-shaped plates of the design can be installed and detached separately, and the segmented design is convenient for operation and maintenance, and the fixing ring can be adjusted or replaced during installation or maintenance.

[0020] In a specific implementation, adjacent two heaters are detachably connected through a connecting block.

[0021] By adopting the technical scheme, the adjacent heaters are connected together through the connecting block, the connection between the heaters is firm and detachable, the whole device is more stable and reliable, and higher efficiency is provided during installation, maintenance and replacement of the heater.

[0022] In a specific implementation, an outer wall of the heater is provided with a heat preservation layer, and the heat preservation layer is arranged along a circumferential direction of the heater.

[0023] By adopting the technical scheme, the design of the heat preservation layer can reduce heat loss, ensure that the heat provided by the heater can be effectively transmitted to the heat exchange pipe to be heated, and help the uniformity of the overall temperature of the heater, prevent local overheating or excessive temperature difference, and improve the overall performance of the heat exchange pipe welding preheating device.

[0024] In a specific implementation, an outer wall of the fixing ring is formed in a flared connection with an inner wall of the tube plate.

[0025] By adopting the above technical scheme, through the expansion joint design, the fixing ring can be firmly installed on the inner wall of the tube sheet to form a close and stable connection, thereby ensuring the stability of the entire preheating device; at the same time, the expansion joint also simplifies the assembly process and improves the reliability and operation convenience of the system.

[0026] To sum up, the beneficial technical effects of the present application are as follows: the heat exchange pipe welding preheating device disclosed in the present application can provide efficient and uniform heating through the innovative design of the fixing ring and the heater, significantly reduce thermal stress and temperature difference in the welding process, thereby effectively avoiding cracks and deformation, improving the quality and reliability of the welded joint; the heater is detachably installed through the support, which facilitates removal after preheating, avoids interference with subsequent welding operations, and can be flexibly adjusted according to heat exchange pipes of different specifications, having strong universality and adaptability; in addition, the temperature control unit accurately controls the temperature of the heater to ensure temperature stability in preheating mode and hydrogen elimination mode, meets different welding requirements, and further enhances the controllability and stability of the welding process. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural schematic view of the preheating device of the embodiment of the present application installed on the heat exchange pipe.

[0028] Figure 2 is a structural schematic view for showing the fixing ring.

[0029] Figure 3 is a structural schematic view for showing the fixing ring and the heater.

[0030] Figure 4 is a structural schematic view for showing the support.

[0031] Legend: 1, fixing ring; 11, arc plate; 2, heater; 3, support; 31, inclined part; 32, flat part; 33, bolt; 4, tension screw; 5, connecting block; 51, screw; 6, heat exchange pipe; 61, tube sheet; 62, pipe head. DETAILED DESCRIPTION

[0032] The following will be described in detail in combination with the accompanying Figures 1-4 The present application will be further described in detail.

[0033] Reference Figures 1-3The embodiment of the present application discloses a heat exchange pipe welding preheating device, in the embodiment, the heat exchange pipe 6 includes a tube sheet 61 and a tube head 62; the heat exchange pipe welding preheating device includes a fixing ring 1 and a plurality of heaters 2, the fixing ring 1 provides a stable platform to facilitate accurate positioning of the heater 2, the fixing ring 1 is composed of a plurality of arc-shaped plates 11, two adjacent arc-shaped plates 11 are connected and fixed through a tension screw 4, forming a ring structure with adjustable size, in the embodiment, the fixing ring 1 is composed of four arc-shaped plates 11 to form a four-equal-part ring structure; the design enables the fixing ring 1 to adapt to heat exchange pipes 6 with different diameters and sizes, thereby having strong versatility and flexibility, by adjusting the number or shape of the arc-shaped plates 11, the heat exchange pipes 6 with different specifications can be conveniently installed and disassembled;

[0034] In actual application, the material of the fixing ring 1 is designed as a channel steel, the fixing ring 1 is installed on the inner side of the tube sheet 61 of the heat exchange pipe 6, and the outer wall of the fixing ring 1 is connected with the inner wall of the tube sheet 61 of the heat exchange pipe 6 in a expansion joint mode, which ensures that the fixing ring 1 is firmly installed and can provide stronger stability in actual use, so that the heater 2 can stably work at the predetermined position;

[0035] The heater 2 is correspondingly arranged with the tube head 62 of the heat exchange pipe 6, and the tube head 62 of the heat exchange pipe 6 is heated, in the embodiment, the heating power of the heater 2 is 200kw; a plurality of heaters 2 are uniformly distributed along the inner periphery of the fixing ring 1, in the embodiment, the heater 2 includes but is not limited to transverse arrangement or longitudinal arrangement, the position of the heater 2 is ensured to correspond to the part to be welded of the tube head 62, so as to uniformly heat; the heater 2 is detachably installed on the fixing ring 1 through a support 3, the position of the heater 2 can be fixed through the support 3 during use, and the heater 2 can be conveniently disassembled after preheating is completed, so as to avoid interference of the heater 2 on the tube head 62 during welding, in the embodiment, the heater 2 can be disassembled in sections after preheating is completed, and welding work is repeatedly and alternately completed, so as to ensure that welding is performed in sections and independent insulation is ensured;

[0036] The present application uniformly distributes the heater 2 on the inner periphery of the fixing ring 1, so as to ensure that the heater 2 can uniformly heat the part of the tube head 62 of the heat exchange pipe 6, and uniform heating helps to reduce thermal stress and avoid cracks or other welding defects caused by excessive temperature difference during welding, thereby improving the quality and reliability of the welded joint; and the detachable installation of the heater 2 through the support 3 enables the heater 2 to be easily disassembled after preheating is completed, avoids interference of the heater 2 on the tube head 62 during welding, ensures that welding work is not affected, and the heater 2 is also easy to maintain or replace, thereby prolonging the service life of the equipment.

[0037] Reference Figure 4In the embodiment, the support 3 is made of channel steel, and includes an inclined portion 31 and two parallel flat portions 32. The inclined portion 31 is connected between the two flat portions 32. One of the flat portions 32 is detachably connected with the heater 2, and the other flat portion 32 is detachably connected with the fixing ring 1. In the embodiment, the two flat portions 32 are respectively connected with the heater 2 and the fixing ring 1 by bolts 33.

[0038] The inclined portion 31 is arranged at an obtuse angle with the flat portion 32. Thus, the support 3 can support the heater 2 at a more effective angle, provide a more suitable contact surface and connection mode, and enhance the stability of the device in actual use, while providing a flexible installation angle and adjustment space.

[0039] The support 3 has good flexibility and practicability. Through the inclined portion 31, the flat portion 32 and the detachable connection mode, the stable installation and adjustment of the heater 2 are ensured, and the installation, maintenance and replacement of the heater 2 are more convenient, and the long-term operation efficiency and economy of the device are improved. The design of the support 3 enables the heater 2 to be evenly distributed along the inner periphery of the fixing ring 1, and ensures that the position of the heater 2 is accurately connected with the pipe head 62 of the heat exchange pipe 6 to be welded.

[0040] Referring to Figure 3 The adjacent two heaters 2 are detachably connected by the connecting block 5. In the embodiment, the connecting block 5 includes but is not limited to being connected with the heater 2 by a screw 51. The connecting block 5 connects the adjacent heaters 2 together, so that the connection between the heaters 2 is firm and detachable. This not only makes the entire device more stable and reliable, but also provides higher efficiency in the installation, maintenance and replacement of the heater 2.

[0041] The outer wall of the heater 2 is provided with a heat preservation layer (not shown in the figure), which is arranged along the circumference of the heater 2. The design of the heat preservation layer can reduce heat loss, ensure that the heat provided by the heater 2 can be effectively transmitted to the heat exchange pipe 6 that needs to be heated, and help the uniformity of the overall temperature of the heater 2, preventing local overheating or excessive temperature difference, thereby effectively improving the overall performance of the heat exchange pipe welding preheating device.

[0042] The heat exchange pipe welding preheating device further comprises a temperature control unit (not shown in the figure), which is used to control the temperature of the heater 2. The heater 2 is respectively provided with a temperature control unit or at most two heaters 2 share one temperature control unit. Separate temperature control units can provide more accurate and independent temperature control, which is suitable for occasions that require strict temperature control. Sharing a temperature control unit is suitable for multiple heaters 2 with similar temperature requirements, which reduces the hardware cost, can reduce the complexity of the control system, and improves the work efficiency;

[0043] In the present embodiment, the temperature control unit includes, but is not limited to, a temperature sensor (such as a thermocouple) and a temperature regulator (or temperature control module); the thermocouple is installed in the heating area near the heater 2 or directly contacts the surface of the heater 2 to realize real-time monitoring of the temperature of the heater 2. In the application scenario of multiple heaters 2, each heater 2 can be configured with an independent thermocouple, or multiple heaters 2 share one thermocouple (for example, through signal averaging processing of the temperature control unit);

[0044] The temperature control module is responsible for receiving and processing the signals of the thermocouple, thereby adjusting the heating power of the heater 2. According to the received temperature data and the preset temperature target value, the temperature control module adjusts the power output of the heater 2 in real time through a feedback control algorithm (such as PID control, fuzzy control, etc.) to ensure that the temperature is stable within the set range. The temperature control module is connected with the power control system of the heater 2, which can control the heating capacity of the heater 2 by adjusting the output current or voltage of the power supply, for example, by adjusting the current size of the heater 2 to control the temperature rise or fall of the heater 2.

[0045] By introducing the temperature control unit, the temperature of the heater 2 can be adjusted and controlled. The temperature control unit monitors the working state of the heater 2 in real time and automatically adjusts the heating power according to the data of the temperature sensor, thereby ensuring that the heater 2 maintains the required preheating temperature range, avoids excessively high or low temperature, and effectively avoids cracks or other welding defects caused by excessive temperature fluctuations, while improving the simplicity of operation and welding quality.

[0046] The heat exchange tube welding preheating device has a preheating mode and a hydrogen removal mode, which can meet the needs of different materials and different welding processes, and improve the controllability and stability of the welding process. The preheating mode is mainly used to stabilize the temperature of the material before welding, reduce the influence of thermal stress, and avoid cracks or deformation during welding. In the preheating mode, the temperature control unit controls the heating temperature of the heater 2 to be ≤150℃. In the present embodiment, preferably, in the preheating mode, the temperature control unit controls the heating temperature of the heater 2 to be 120-150℃.

[0047] The hydrogen removal mode is used to remove hydrogen generated during the welding process to avoid hydrogen embrittlement and ensure the strength and toughness of the welded joint. The control temperature of the hydrogen removal mode should be higher than the preheating temperature but not exceed the maximum safe working temperature of the material. In the hydrogen removal mode, the temperature control unit controls the heating temperature of the heater 2 to be ≤350℃. In the present embodiment, preferably, in the hydrogen removal mode, the temperature control unit controls the heating temperature of the heater 2 to be 300-350℃.

[0048] The implementation principle of the embodiment of the present application is as follows: before use, installation work is performed first, a fixing ring 1 of a corresponding size is made according to the size of the tube plate 61 of the heat exchange pipe 6, four arc-shaped plates 11 are spliced to form a four-equal-part annular structure, and are connected and fixed through the tensioning screws 4; then a plurality of heaters 2 are fixed on the fixing ring 1 through the supports 3 according to the design requirements, to ensure that the heaters 2 are evenly distributed along the inner periphery of the fixing ring 1, and the positions of the heaters 2 need to be ensured to correspond to the pipe heads 62 of the heat exchange pipes 6 to be welded, so as to efficiently preheat the pipe heads 62; finally, the fixing ring 1 is installed on the inner side of the tube plate 61 of the heat exchange pipe 6, and the fixing ring 1 forms a tight joint with the inner wall of the tube plate 61, to ensure that it is firm and reliable, and the installation is completed.

[0049] When preheating is needed, the preheating mode is started, the heating temperature of the heater 2 is controlled by the temperature control unit according to the material of the heat exchange pipe 6 to be within 120-150 DEG C, after the heater 2 is started, electric energy or other forms of energy is converted into heat through the heater 2, and is uniformly transmitted to the pipe head 62 part of the heat exchange pipe 6, the heater 2 heats the pipe head 62 to the required preheating temperature through heat radiation, convection and other modes; when the preheating is completed and the pipe head 62 part reaches the required temperature, the worker can easily disassemble the heater 2 through the support 3, after disassembly, the heater 2 will not interfere with the welding operation, and the worker can smoothly perform the welding work.

[0050] After welding, hydrogen removal work is needed, the heater 2 is reinstalled on the fixing ring 1 according to the foregoing installation steps, the hydrogen removal mode is started, and the heating temperature of the heater 2 is controlled by the temperature control unit to be within 300-350 DEG C, to remove the hydrogen generated in the welding process, avoid hydrogen embrittlement, and ensure the strength and toughness of the welded joint.

[0051] The heat exchange pipe welding preheating device disclosed in the present application can provide efficient and uniform heating through the innovative design of the fixing ring 1 and the heater 2, significantly reduces thermal stress and temperature difference in the welding process, thereby effectively avoiding cracks and deformation, and improving the quality and reliability of the welded joint; the heater 2 is detachably installed through the support 3, which is convenient to disassemble after preheating, avoids interference with subsequent welding operations, and can be flexibly adjusted according to heat exchange pipes 6 of different specifications, and has strong universality and adaptability; in addition, the temperature control unit accurately controls the temperature of the heater 2, ensures the temperature stability in the preheating mode and the hydrogen removal mode, meets different welding requirements, and further enhances the controllability and stability of the welding process; the design of the device improves the operation convenience, the service life of the equipment and the overall economy.

[0052] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A heat exchanger tube welding preheating device, characterized in that: It includes a fixed ring (1) and several heaters (2). The heaters (2) are detachably mounted on the fixed ring (1) via a support (3). The several heaters (2) are evenly distributed along the inner circumference of the fixed ring (1). The heaters (2) are correspondingly arranged with the tube head (62) of the heat exchange tube (6). The fixed ring (1) is installed on the inner side of the tube sheet (61) of the heat exchange tube (6).

2. The heat exchanger tube welding preheating device according to claim 1, characterized in that: It also includes a temperature control unit, which is used to control the temperature of the heater (2).

3. The heat exchanger tube welding preheating device according to claim 2, characterized in that: Each heater (2) is equipped with a separate temperature control unit or at most two heaters (2) share a single temperature control unit.

4. The heat exchanger tube welding preheating device according to claim 1, characterized in that: The support (3) includes an inclined part (31) and two parallel straight parts (32). The inclined part (31) is connected between the two straight parts (32). One of the straight parts (32) is detachably connected to the heater (2), and the other straight part (32) is detachably connected to the fixing ring (1).

5. The heat exchanger tube welding preheating device according to claim 4, characterized in that: The inclined portion (31) and the straight portion (32) are set at an obtuse angle.

6. The heat exchanger tube welding preheating device according to claim 1, characterized in that: The fixing ring (1) is composed of several arc-shaped plates (11), and two adjacent arc-shaped plates (11) are fixed together by tension screws (4).

7. The heat exchanger tube welding preheating device according to claim 1, characterized in that: The two adjacent heaters (2) are detachably connected by a connecting block (5).

8. The heat exchanger tube welding preheating device according to claim 1, characterized in that: The outer wall of the heater (2) is provided with a heat insulation layer, which is arranged along the circumference of the heater (2).

9. The heat exchanger tube welding preheating device according to claim 1, characterized in that: The outer wall of the fixing ring (1) forms an expansion joint with the inner wall of the tube sheet (61).

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