U-tube heat exchanger suitable for large temperature difference

Abstract

The application provides a U-shaped tube heat exchanger suitable for large temperature difference conditions, which comprises a tube box, a shell and a tube plate, the tube box and the shell are connected through the tube plate, the tube plate is composed of a flexible thin tube plate and a thick tube plate, and the flexible thin tube plate and the thick tube plate form a cooling channel, the beneficial effects of the application are as follows: the tube plate adopts a double-layer structure composed of the flexible thin tube plate and the thick tube plate, the flexible thin tube plate can reduce the temperature difference stress by deforming itself, the tube hole on the flexible thin tube plate is connected with the inlet end of the U-shaped tube, the tube hole of the outer circular ring of the thick tube plate is connected with the outlet end of the U-shaped tube, the high-temperature area of the tube plate has better expansion freedom, and the temperature difference stress of the tube plate can be further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to heat exchanger technical field, especially to a U-tube heat exchanger suitable for large temperature difference conditions. BACKGROUND

[0002] The U-tube heat exchanger is a kind of multi-tube heat exchanger, only one tube sheet is arranged, due to the compact structure, tube bundle can be free expansion, easy to install and overhaul and other characteristics and is widely used in heat exchange device in various industries, the tube bundle inlet and outlet of U-tube heat exchanger are connected on the same tube sheet, when there is a large temperature difference between the inlet and outlet of tube medium, the tube sheet will generate a large temperature difference stress due to uneven heating. The hairpin type heat exchanger can solve the problem of large temperature difference between the inlet and outlet of tube, but it cannot meet the situation that the space of equipment is limited and the structure is compact, the flexible tube sheet can withstand higher temperature as a whole, but it is not suitable for the tube sheet of U-tube heat exchanger as a whole.

[0003] The temperature difference between the inlet and outlet of tube medium of conventional U-tube heat exchanger with upper and lower or left and right partitioned tube arrangement generally cannot exceed 80 DEG C, the U-tube heat exchanger with inner ring outer ring fountain type tube arrangement or inlet and outlet cross tube arrangement can withstand larger temperature difference between the inlet and outlet of tube medium, but from the application situation, it is generally not more than 120 DEG C. In some occasions, the temperature difference between the inlet and outlet of tube medium is required to exceed 150 DEG C, and the existing structure cannot guarantee the structural safety. SUMMARY

[0004] In order to overcome the above problems in the prior art, the present application provides a U-tube heat exchanger suitable for large temperature difference conditions.

[0005] The present application discloses a U-tube heat exchanger suitable for large temperature difference conditions, which comprises a tube box, a shell and a tube sheet, the tube box and the shell are connected through the tube sheet, the tube sheet is composed of a flexible thin tube sheet and a thick tube sheet, the flexible thin tube sheet and the thick tube sheet form a cooling channel, and the tube sheet is cooled.

[0006] On this basis, the tube box comprises an inner tube box and an outer tube box, and the inner tube box and the outer tube box adopt a split structure, the tube medium in the outer tube box can cool and protect the inner tube box, the inner tube box is composed of cylinder sections and a cone, the cone is installed between adjacent cylinder sections, expansion joints and flanges are installed on the cylinder sections, the inner tube box is filled with hot medium which just enters the heat exchanger, at this time, the temperature is high, so that the inner tube box expands greatly, the outer tube box is filled with hot medium which is cooled by heat exchange, and the temperature is relatively low, so that the outer tube box expands little, thereby forming a displacement difference, the displacement difference is absorbed by the elongation or compression of the expansion joints, and the outer tube box comprises a head and a cylinder body, the cylinder body is provided with a tube inlet connecting pipe, a tube outlet connecting pipe, a tube sheet cooling pipe and a manhole, and the tube inlet connecting pipe is connected with the inner tube box.

[0007] On this basis, the tube plate cooling pipe extends to the outside of the cylinder and to the inside of the channel, and the tube plate cooling medium is introduced through the tube plate cooling pipe.

[0008] On this basis, the shell is used for containing the cooling medium and the tube bundle, the U-shaped tube and the baffle plate are installed in the shell, the U-shaped tube penetrates through the baffle plate and is connected with the tube plate at both ends, and the shell is provided with a shell inlet connecting pipe and a shell outlet connecting pipe, which are used for the inflow and outflow of the cooling medium.

[0009] On this basis, the first pipe hole is formed in the circular flat plate of the flexible thin tube plate, the second pipe hole is formed in the inner ring and the outer ring of the thick tube plate respectively, and the circular arc plate is arranged on the peripheral ring of the flexible thin tube plate and is used for absorbing thermal expansion.

[0010] On this basis, the second pipe hole of the inner ring corresponds to the first pipe hole one by one, and the inlet end of the U-shaped tube provides a pipe-penetrating channel.

[0011] On this basis, the first pipe hole is connected with the inlet end of the U-shaped tube, the second pipe hole of the outer ring of the thick tube plate is connected with the outlet end of the U-shaped tube, the second pipe hole of the inner ring of the thick tube plate provides a pipe-penetrating channel for the inlet end of the U-shaped tube, and the outer ring uniformly limits the expansion of the inner ring, so that the capacity of the tube plate to withstand temperature difference is improved.

[0012] On this basis, the U-shaped tube is arranged in a fountain type, and is not limited to the existing regular arrangement mode, and can be arranged according to requirements.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] (1) The U-shaped tube heat exchanger suitable for large temperature difference conditions comprises a flexible thin tube plate and a thick tube plate, the flexible thin tube plate can reduce the temperature difference stress by deforming itself, the first pipe hole of the flexible thin tube plate is connected with the inlet end of the U-shaped tube, the pipe hole of the outer ring of the thick tube plate is connected with the outlet end of the U-shaped tube, the high-temperature area of the tube plate has better expansion freedom, the temperature difference stress of the tube plate can be further reduced, the pipe hole of the inner ring of the thick tube plate provides a pipe-penetrating channel for the inlet end of the U-shaped tube, the outer ring uniformly limits the expansion of the inner ring, the whole tube plate is relatively uniformly heated, the temperature difference stress is small, and the capacity of the tube plate to withstand temperature difference is improved.

[0015] (2) The U-tube heat exchanger suitable for large temperature difference conditions of the present application, the inner tube box and the outer tube box are separated, the tube side outlet medium in the outer tube box can cool and protect the inner tube box, the cavity formed between the flexible thin tube plate and the thick tube plate is used to pass the tube plate cooling tube into the tube plate cooling medium, the cooling medium enters the shell through the gap between the heat exchange tube and the inner ring tube hole of the thick tube plate, and flows out together with the cooling medium in the shell, and the structure is still safe when the temperature difference between the inlet and outlet of the tube side medium exceeds 150 DEG C, and the structure is relatively simple and compact, the manufacturing cost and the occupied space can be saved, and the maintenance is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the schematic diagram of the cross-sectional structure of the U-tube heat exchanger of the present application;

[0017] Figure 2 is the schematic diagram of the cross-sectional structure of the outer tube box of the U-tube heat exchanger of the present application;

[0018] Figure 3 is the schematic diagram of the cross-sectional structure of the inner tube box of the U-tube heat exchanger of the present application;

[0019] Figure 4 is the schematic diagram of the tube plate structure of the U-tube heat exchanger of the present application;

[0020] Figure 5 is the schematic diagram of the cross-sectional structure of the tube plate of the U-tube heat exchanger of the present application;

[0021] In the figure: 1, tube inlet connection pipe, 2, inner tube box, 2-1, expansion joint, 2-2, flange, 2-3, cylinder joint, 2-4, cone, 3, tube plate, 3-1, flexible thin tube plate, 3-2, thick tube plate, 3-3, first tube hole, 3-4, second tube hole, 3-5, circular arc plate, 4, U-tube, 5, baffle, 6, outer tube box, 6-1, head, 6-2, cylinder, 6-3, manhole, 7, tube outlet connection pipe, 8, tube plate cooling tube, 9, shell, 10, shell inlet connection pipe, 11, shell outlet connection pipe. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application.

[0023] The present application discloses a U-tube heat exchanger suitable for large temperature difference conditions, referring to Figure 1 , comprising a tube box, a shell 9 and a tube plate 3, the tube box and the shell 9 are connected through the tube plate 3, the tube plate 3 comprises a flexible thin tube plate 3-1 and a thick tube plate 3-2, the flexible thin tube plate 3-1 and the thick tube plate 3-2 form a cooling channel, and the tube plate 3 is cooled.

[0024] Referring toFigure 2 And Figure 3 As a preferred embodiment of the present application, in the present embodiment, the tube box comprises an inner tube box 2 and an outer tube box 6, and the inner tube box 2 and the outer tube box 6 are in a split structure, the medium in the tube passage outlet of the outer tube box 6 can play a cooling protection role on the inner tube box 2, the inner tube box 2 is composed of cylinder segments 2-3 and a cone 2-4, the cone 2-4 is installed between adjacent cylinder segments 2-3, expansion joints 2-1 and flanges 2-2 are installed on the cylinder segments 2-3, the inner tube box 2 is filled with hot medium just entering the heat exchanger, at this time, the temperature is high, which causes the inner tube box 2 to expand greatly; the outer tube box 6 is filled with hot medium which has been cooled by heat exchange, and the temperature is relatively low, so the outer tube box 6 expands little, thereby forming a displacement difference, the displacement difference is absorbed by the elongation or compression of the expansion joints 2-1, the outer tube box 6 comprises a head 6-1 and a cylinder body 6-2, the cylinder body 6-2 is provided with a tube passage inlet connecting pipe 1, a tube passage outlet connecting pipe 7, a tube plate cooling pipe 8 and a manhole 6-3, and the tube passage inlet connecting pipe 1 is connected with the inner tube box 2.

[0025] Reference Figure 1 As a preferred embodiment of the present application, in the present embodiment, one end of the tube plate cooling pipe 8 extends to the outside of the cylinder body 6-2, and the other end extends into the channel, and the tube plate cooling medium is introduced through the tube plate cooling pipe 8.

[0026] As a preferred embodiment of the present application, in the present embodiment, a shell 9 is used to accommodate the cooling medium and the tube bundle, the shell 9 is provided with U-shaped tubes 4 and baffles 5, the U-shaped tubes 4 pass through the baffles 5 and are connected with the tube plate 3 at both ends, and the shell 9 is provided with a shell passage inlet connecting pipe 10 and a shell passage outlet connecting pipe 11 for the inflow and outflow of the cooling medium.

[0027] Reference Figure 4 And Figure 5 As a preferred embodiment of the present application, in the present embodiment, the first tube hole 3-3 is formed in the circular flat plate of the flexible thin tube plate 3-1, the second tube hole 3-4 is formed in the inner ring and the outer ring of the thick tube plate 3-2 respectively, and the circular arc plate 3-5 is arranged around the flexible thin tube plate 3-1, and the circular arc plate 3-5 plays a role of absorbing thermal expansion.

[0028] As a preferred embodiment of the present application, in the present embodiment, the second tube hole 3-4 of the inner ring corresponds to the first tube hole 3-3 one by one, and provides a tube passing channel for the inlet end of the U-shaped tube 4.

[0029] As a preferred embodiment of the present application, in the embodiment, the first tube hole 3-3 is connected with the inlet end of the U-shaped tube 4, the second tube hole 3-4 of the outer ring of the thick tube plate 3-2 is connected with the outlet end of the U-shaped tube 4, and the second tube hole 3-4 of the inner ring of the thick tube plate 3-2 provides a tube passing channel for the inlet end of the U-shaped tube 4, and the outer ring uniformly limits the expansion of the inner ring, thereby improving the ability of the tube plate 3 to withstand temperature difference.

[0030] As a preferred embodiment of the present application, in the embodiment, the U-shaped tube 4 is arranged in a fountain type.

[0031] The working principle of the present application is as follows: in actual use, the tube passage inlet connecting pipe 1 is used to introduce hot medium, the tube passage inlet connecting pipe 1 is arranged on the outer tube box 6, the hot medium enters the inner tube box 2 from the tube passage inlet connecting pipe 1, the inner tube box 2 is installed in the outer tube box 6, and a separated structure of the inner tube box and the outer tube box 6 is adopted, a space for collecting tube passage outlet medium is formed between the outer tube box 6 and the inner tube box 2, and the outer tube box 6 plays a cooling role on the inner tube box 2, the outer tube box 6 comprises a head 6-1 and a cylinder body 6-2, the cylinder body 6-2 is provided with the tube passage inlet connecting pipe 1, the tube passage outlet connecting pipe 7, the tube plate cooling pipe 8 and the manhole 6-3, the manhole 6-3 is used for entering and exiting during internal maintenance, the tube passage outlet connecting pipe 7 is used to lead out the hot medium, the inner tube box 2 is composed of cylinder segments 2-3 and a cone body 2-4, the cone body 2-4 is installed between two adjacent cylinder segments 2-3, the cylinder segment 2-3 is provided with the expansion joint 2-1 and the flange 2-2, the flange 2-2 is used for disassembly and assembly during internal maintenance, and the expansion joint 2-1 is used to absorb the expansion displacement difference of the inner tube box 2 and the outer tube box 6 due to different temperatures, the inner tube box 2 is the hot medium just entering the heat exchanger, at this time, the temperature is high, which causes the expansion of the inner tube box 2 to be large; the outer tube box 6 is the hot medium after heat exchange and temperature reduction, the temperature is relatively low, and thus the expansion of the outer tube box 6 is small, thereby forming the displacement difference, and the expansion joint 2-1 is elongated or compressed to absorb the displacement difference.

[0032] The inner tube box 2 is connected with the tube passage inlet connecting pipe 1 and the tube plate 3, and separates the inlet and outlet channels of the hot medium, the shell 9 is used to contain the cold medium and the tube bundle, the shell 9 is provided with the shell passage inlet connecting pipe 10 and the shell passage outlet connecting pipe 11, a shell passage medium flow space is formed between the shell 8 and the U-shaped tube 4, the shell passage inlet connecting pipe 10 is used to introduce the cold medium, the shell passage outlet connecting pipe 11 is used to lead out the cold medium, the U-shaped tube 4 and the baffle 5 are installed in the shell 9, the U-shaped tube 4 is used to realize heat exchange between the cold and hot media, and the baffle 5 is used to deflect the shell passage medium and support the U-shaped tube 4, the U-shaped tube 4 passes through the baffle 5 and is connected with the tube plate 3 at both ends, the tube box is connected with the shell 9 through the tube plate 3, the hot medium enters the inner tube box 2 from the tube passage inlet connecting pipe 1, and then is uniformly distributed into the U-shaped tube 4, the cold medium enters the shell 9 from the shell passage inlet connecting pipe 10 and is deflected through the baffle 5, the hot medium transfers heat to the cold medium through the U-shaped tube 4, and then is collected in the outer tube box 6 and flows out from the tube passage outlet connecting pipe 7, and the cold medium flows out from the shell passage outlet connecting pipe 11.

[0033] Because the temperature distribution of the existing U-tube heat exchanger tube plate is uneven, the temperature difference borne is small, the tube plate 3 comprises a flexible thin tube plate 3-1 and a thick tube plate 3-2, the flexible thin tube plate 3-1 is provided with a circular arc plate 3-5, the circular arc plate 3-5 plays a role of absorbing thermal expansion, the tube hole of the flexible thin tube plate 3-1 is connected with the inlet end of the U-tube 4, the outer circular ring tube hole of the thick tube plate 3-2 is connected with the outlet end of the U-tube 4, the tube hole on the outer circular ring of the thick tube plate 3-2 corresponds to the tube hole on the flexible thin tube plate 3-1, the tube hole of the inner circle of the thick tube plate 3-2 provides a tube passing channel for the inlet end of the U-tube 4, the U-tube 4 is arranged in a fountain type, the high-temperature end of the inlet is uniformly distributed on the inner circle of the flexible thin tube plate 3-1, the low-temperature end of the outlet is uniformly distributed on the outer circular ring of the thick tube plate 3-2, the outer circle uniformly limits the expansion of the inner circle, so that the capacity of the tube plate 3 to bear the temperature difference is improved. The circular flat plate of the flexible thin tube plate 3-1 is internally provided with a first tube hole 3-3, the inner circle and the outer circular ring of the thick tube plate 3-2 are respectively provided with a second tube hole 3-4, the tube plate cooling pipe 8 is connected with the tube plate cooling medium, the tube plate cooling medium is cooled in the gap between the flexible thin tube plate 3-1 and the thick tube plate 3-2, and then flows into the inside of the shell 9, so that the tube plate cooling medium is connected with the flexible thin tube plate 3-1 and the thick tube plate 3-2 to form a separate cavity and is connected with the tube plate cooling medium. The tube plate cooling medium enters the shell 9 through the gap between the U-tube 4 and the second tube hole 3-4 of the inner circle, is discharged together with the cooling medium of the shell side through the shell side outlet connection pipe 11, is further cooled and protected, the structure can meet the condition that the inlet and outlet temperature difference of the tube side medium exceeds 150 DEG C.

[0034] In the description of the present application, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inner", "front", "central", "both ends" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "setting", "connecting", "fixing", "screw connection", "pad setting" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances by those skilled in the art.

[0036] The foregoing description has shown and described preferred embodiments of the application, but it will be understood that the application is not limited to the particular embodiments shown and described, as such will have many modifications, permutations, additions and subtractions and changes thereof, as will be apparent to those skilled in the art. It is therefore contemplated to cover in the appended claims all such changes and modifications that come within the scope of the application.

Claims

1. A U-tube heat exchanger suitable for large temperature difference conditions comprising a tube sheet (3), a shell (9) and a tube sheet (3), characterized in that: The tube box and the shell (9) are connected through the tube plate (3), the tube plate (3) is composed of a flexible thin tube plate (3-1) and a thick tube plate (3-2), and a cooling channel is formed between the flexible thin tube plate (3-1) and the thick tube plate (3-2); The first tube hole (3-3) is arranged in the circular flat plate of the flexible thin tube plate (3-1), and the second tube hole (3-4) is arranged in the inner ring and the outer circular ring of the thick tube plate (3-2), and the circular arc plate (3-5) is arranged on the periphery of the flexible thin tube plate (3-1); The first tube hole (3-3) is connected with the inlet end of the U-shaped tube (4), the second tube hole (3-4) of the outer circular ring of the thick tube plate (3-2) is connected with the outlet end of the U-shaped tube (4), and the second tube hole (3-4) of the inner ring of the thick tube plate (3-2) provides a tube passing channel for the inlet end of the U-shaped tube (4); the U-shaped tube (4) is arranged in a fountain type.

2. The U-tube heat exchanger suitable for large temperature difference conditions as claimed in claim 1 wherein: The tube box comprises an inner tube box (2) and an outer tube box (6), the inner tube box (2) is composed of cylinder segments (2-3) and cones (2-4), the cones (2-4) are installed between adjacent cylinder segments (2-3), the cylinder segments (2-3) are provided with expansion joints (2-1) and flanges (2-2), and the outer tube box (6) comprises a head (6-1) and a cylinder body (6-2), the cylinder body (6-2) is provided with a tube-pass inlet connecting pipe (1), a tube-pass outlet connecting pipe (7), a tube plate cooling pipe (8) and a manhole (6-3), and the tube-pass inlet connecting pipe (1) is connected with the inner tube box (2).

3. The U-tube heat exchanger suitable for large temperature difference conditions as claimed in claim 2 wherein: One end of the tube plate cooling pipe (8) extends to the outside of the cylinder body (6-2), and the other end extends into the channel.

4. The U-tube heat exchanger suitable for large temperature difference conditions as claimed in claim 1 wherein: The U-shaped tube (4) and the baffle (5) are installed in the shell (9), the U-shaped tube (4) passes through the baffle (5) and is connected with the tube plate (3) at both ends, and the shell (9) is provided with a shell-pass inlet connecting pipe (10) and a shell-pass outlet connecting pipe (11).

5. The U-tube heat exchanger suitable for large temperature difference conditions according to any one of claims 1-4, characterized in that: The second tube hole (3-4) of the outer circular ring corresponds to the first tube hole (3-3) one by one.

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