Shell-and-tube heat exchange equipment and using method thereof

Abstract

The invention relates to the field of petrochemical engineering devices and equipment, and discloses shell-and-tube heat exchange equipment and a using method thereof.The shell-and-tube heat exchange equipment comprises a shell and a tube plate, the tube plate divides the shell into a shell pass barrel and a tube box barrel, and a first fluid inlet is formed in the side, away from the tube plate, of the shell pass barrel; a shell pass internal part is arranged in the shell pass cylinder along the wall with a gap, one end, close to the tube plate, of the shell pass internal part is suspended, and the other end of the shell pass internal part circumferentially and radially extends to the inner wall of the shell pass cylinder; a pressure-bearing shell subjected to heat insulation treatment is arranged in the shell pass barrel, the adjusting assembly communicates with the space in the pressure-bearing shell and is provided with an adjusting part, the adjusting assembly further communicates with the annular space flow channel, and an outlet of the adjusting assembly extends out of the shell pass barrel to form a first fluid outlet; the tube box cylinder is provided with a second fluid inlet, a heat exchange tube assembly and a collecting tube assembly are inserted into the tube plate, one side of the collecting tube assembly is communicated with the heat exchange tube assembly, the other side of the collecting tube assembly extends out of the shell to form a second fluid outlet, and the side, close to the tube box cylinder, of the heat exchange tube assembly is communicated with the tube box cylinder.

Description

Technical Field

[0001] This invention relates to the field of petrochemical plant equipment, specifically to a shell-and-tube heat exchanger and its usage method. Background Technology

[0002] In petrochemical plants, heat exchange equipment is frequently used. Common heat exchange equipment includes shell-and-tube heat exchangers, wound-tube heat exchangers, and plate heat exchangers, with shell-and-tube heat exchangers being the most commonly used. Steam is an important utility medium in chemical plants. Steam can be divided into saturated steam and superheated steam. Almost all chemical plants have steam requirements, with high-pressure superheated steam being particularly valuable. High-pressure superheated steam in typical chemical plants ranges from 6.0 MPaG to 14.0 MPaG and has a temperature between 450℃ and 540℃. This level of superheated steam can be directly used to drive steam turbines for power generation and is a crucial power source for chemical plants. Normally, high-pressure superheated steam in chemical plants is provided by power boilers. However, in some special cases, such as waste heat boilers in methanation furnaces, ethylene cracking furnaces, and conversion furnaces, saturated steam with a pressure of 10 MPaG to 12 MPaG (temperature 311℃ to 325℃) may be produced as a byproduct. How to superheat these saturated steams to 500℃~525℃ has always been a difficult problem.

[0003] Existing solutions often aim to superheat the saturated steam to the required temperature in the heat exchanger. However, under harsh high-temperature and high-pressure application conditions, steam heat exchangers face problems such as the inability to select suitable materials for the tube sheet structure and the easy leakage of heat exchange tube joints.

[0004] On the other hand, in chemical processes, the input of high-temperature gas is not a stable process and is often adjusted with load fluctuations. Current methods typically involve adding a bypass to the tube side of the heat exchanger and installing valves on the bypass to consume or compensate for the impact of high-temperature gas flow fluctuations on the heat exchange of saturated steam. However, under high-temperature and high-pressure application conditions, the requirements for bypass valves, pipe materials, and pipe stress are extremely high, making this impractical in actual engineering.

[0005] Taking actual operating conditions as an example, the structure of the fixed tube sheet heat exchanger 1 in the existing design is as follows: Figure 13As shown, the first medium flows through the tube side, and the second medium flows through the shell side. In the tube side of the fixed tube sheet heat exchanger 1, the first medium enters the front tube box 113 through the first gas inlet 101, flows through the heat exchange capillary tubes 12 to the rear tube box 114, and exits from the first gas outlet 102. In the shell side of the fixed tube sheet heat exchanger 1, the second medium enters the shell-side structure 11 through the second gas inlet 103, exchanges heat with the first medium through the first baffle 13 within the shell-side structure 11, and exits through the second gas outlet 104. The heat exchange capillary tubes 12 are connected to the front tube sheet 111 and the rear tube sheet 112 respectively. The first gas flow direction 14 and the second gas flow direction 15 are as follows: Figure 13 As shown.

[0006] When the first medium is a relatively high-temperature, high-pressure gas and the second medium is a relatively low-temperature, high-pressure gas, the left side of the front-end tube sheet 113 and the front-end tube plate 111 are both in a high-temperature, high-pressure environment, while the right side of the front-end tube plate 111 is also in the environment of the second medium after heat exchange, which is still a high-temperature, high-pressure environment. Under the dual high-temperature, high-pressure conditions of the two media, the front-end tube plate 111 has a large diameter, generally ≥600mm. Under such design conditions, it is impossible to select a suitable material. Furthermore, under the high-temperature, high-pressure environment of the front-end tube plate 111, the tube joints of the heat exchange capillary tubes 12 are extremely prone to leakage, potentially causing an accident. For the shell-side structure 11, subjected to the high-temperature, high-pressure environment before heat exchange of the first medium, a suitable material cannot be selected in the design either.

[0007] On the other hand, fixed tubesheet heat exchanger 1 has another problem. The input materials in chemical processes are not a stable process and often change with load fluctuations. For example... Figure 13 In the design shown, assuming the flow rate of the second gas is constant, if the flow rate of the first gas entering the first gas inlet 101 increases, the temperature of the second gas exiting the second gas outlet 104 will rise accordingly; conversely, if the flow rate of the first gas entering the first gas inlet 101 decreases, the temperature of the second gas exiting the second gas outlet 104 will decrease accordingly. Taking high-temperature synthesis gas as the first gas and saturated steam as the second gas as an example, the temperature of the high-temperature superheated steam needs to be within a certain range; if it exceeds this range, the system will not be able to withstand it. When the input flow rate of the high-temperature synthesis gas changes, the outlet temperature of the superheated steam will also change accordingly. In conventional heat exchangers, this problem is solved by adding a bypass. For example... Figure 14 As shown, a bypass 16 is installed in the pipe side, and a bypass valve 161 is installed on the bypass 16. A thermometer is installed on the temperature pipeline of the second gas outlet 104, as shown. Figure 14As shown, the opening and closing degree of the bypass valve 161 is adjusted by setting the temperature of the thermometer, ultimately achieving a reasonable value for the superheated steam temperature. However, in this heat exchanger, the high-temperature synthesis gas has a high temperature (T≥600℃) and high pressure (P≈5MPaG), placing extremely high demands on the bypass valve 161, pipe materials, and pipe stress, which cannot be achieved in engineering practice. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of how to raise superheated steam to higher temperatures and the impact of unstable high-temperature fluid input on heat exchange efficiency in existing technologies. This invention provides a shell-and-tube heat exchanger that, through a rational flow channel structure, allows for the introduction of high-temperature and high-pressure media into both the tube side and shell side. Furthermore, the tube sheet structure and regulating components are not simultaneously subjected to high-temperature and high-pressure environments, enabling material selection. Moreover, in cases of unstable fluid input, the regulating components can adjust the flow rate of the fluid as needed.

[0009] To achieve the above objectives, the present invention provides a shell-and-tube heat exchanger, including a shell and a tube sheet disposed inside the shell. The tube sheet divides the shell into a shell-side cylinder and a tube box cylinder, and a first fluid inlet is provided on the side of the shell-side cylinder away from the tube sheet.

[0010] The shell-side cylinder has a gap along the inner wall of the shell-side cylinder. The shell-side cylinder is hollow and open at both ends. One end of the shell-side cylinder near the tube sheet is suspended, and the other end extends radially to the inner wall of the shell-side cylinder and is sealed to the inner wall of the shell-side cylinder to form an annular flow channel.

[0011] The part of the shell-side cylinder away from the shell-side internals is a pressure-bearing shell that has been heat-insulated. The regulating component is located inside the pressure-bearing shell. The regulating component is connected to the pressure-bearing shell through the regulating parts to control the fluid flow rate. The regulating component is also connected to the annular gap flow channel. The outlet of the regulating component extends out of the shell-side cylinder to form the first fluid outlet.

[0012] The tube box body is provided with a second fluid inlet. The tube sheet is fitted with heat exchange tube assemblies and collection tube assemblies, both of which extend into the shell-side internals. The collection tube assembly is located on one side of the shell-side internals and communicates with the heat exchange tube assembly. The other side extends out of the shell to form a second fluid outlet. The side of the heat exchange tube assembly closest to the tube box body is connected to the tube box body.

[0013] The first fluid is delivered into the shell-side cylinder through the first fluid inlet, flows through the pressure-bearing shell, and then enters the shell-side internals. After exchanging heat with the second fluid in the heat exchange tube assembly, it flows through the annular channel into the regulating assembly. There, it mixes with any unexchanged first fluid that may have entered the regulating assembly from the pressure-bearing shell, and then exits from the first fluid outlet through the regulating assembly. The second fluid enters the tube box cylinder through the second fluid inlet and then enters the heat exchange tube assembly on the tube sheet. It exchanges heat with the first fluid in the shell-side internals within the shell-side cylinder, and then exits the shell through the collection tube assembly. A thermometer is installed at the second fluid outlet to monitor the temperature of the second fluid after heat exchange. When the flow rate of the first fluid is unstable, the temperature of the second fluid after heat exchange may not match the preset value. In this case, it is necessary to adjust the regulating component of the regulating assembly to adjust the flow rate of the first fluid entering the regulating assembly, thereby adjusting the heat exchange efficiency and ultimately adjusting the fluid temperature at the second fluid outlet.

[0014] When the first fluid medium is a relatively high-temperature fluid and the second fluid medium is a relatively low-temperature fluid, the tube sheet on the side closer to the shell is in contact with the first fluid after heat exchange and cooling, while the side closer to the tube box is in contact with the second fluid, which is newly introduced and has not yet undergone heat exchange. Neither side of the tube sheet structure is in direct contact with the relatively high-temperature fluid, thus providing better protection for the tube sheet structure and allowing for selection of the tube sheet material.

[0015] The fluid flowing through the regulating component is mainly the first fluid that has been cooled by heat exchange and flows in through the annular channel, and a small amount of the first fluid that has not been cooled is introduced through the pressure-bearing shell. When the small amount of the first fluid that has not been cooled and the large amount of the first fluid that has been cooled by heat exchange are mixed, the overall temperature of the first fluid in the regulating component is close to the temperature of the cooled first fluid. Moreover, there is no pressure difference between the inside and outside of the regulating component. Therefore, the regulating component does not need to bear the relatively high temperature and high pressure fluid at the same time, which makes the material of the regulating component selective.

[0016] The setting of the regulating component makes the flow rate of the first fluid entering the regulating component in the pressure-bearing shell controllable, thereby stabilizing the flow rate of the first fluid that exchanges heat with the second fluid. This allows the second fluid to exchange heat in the heat exchange environment of the first fluid with a stable flow rate, thereby ensuring the stable temperature of the second fluid after heat exchange.

[0017] Preferably, the regulating component includes two sets of inlets and one set of outlets. The liner connecting pipes converge into the manifold to form the first set of inlets, the internal space of the pressure-bearing shell is connected to the manifold to form the second set of inlets, and the manifold is connected to the outside of the shell to form a set of outlets; wherein, the flow rate of fluid flowing in through the second set of inlets is adjustable.

[0018] The regulating component has two sets of inlets, which can respectively introduce the first fluid that has been cooled by heat exchange and flows through the annular gap channel, and the first high-temperature fluid that has not undergone heat exchange and flows in from inside the pressure-bearing shell. The two fluids are mixed in the manifold, and one set of outlets discharges the mixed fluid from the manifold to the outside of the shell. The manifold collects the fluids before discharging them, providing a space for the collection and discharge of the fluids.

[0019] Preferably, the manifold is an annular pipe, and the connecting pipe is connected to the manifold to form a second set of inlets. The regulating components include a valve, a valve stem, and an actuator. The valve is located at the inlet of the connecting pipe, and the valve stem connected to the valve extends out of the housing and is connected to the actuator.

[0020] A preferred embodiment of the manifold is a ring-shaped pipe structure. Multiple sets of liner-connecting pipes can be evenly distributed circumferentially within the manifold, facilitating fluid flow from the annular gap into the manifold. The connection between the pressure-bearing housing and the manifold is achieved through a connecting pipe, forming a second set of inlets. A regulating component, consisting of a valve, valve stem, and actuator, can regulate the fluid flow rate entering the manifold through the second set of inlets. Placing the valve at the inlet of the connecting pipe allows for flow rate control of the fluid flowing into the manifold through the connecting pipe. By connecting the valve stem to the valve, the actuator controlling the valve can be located outside the housing for easy manual operation.

[0021] Preferably, one end of the liner connecting pipe is connected to the annular gap flow channel, and the other end is connected to the manifold.

[0022] The annular flow channel is annular, and the manifold is also annular. Multiple sets of bushing connecting pipes are set to introduce the fluid from the annular flow channel into the manifold. The bushing connecting pipes can be evenly distributed along the circumference of the manifold so that the fluid from the annular flow channel can flow quickly into the manifold and be discharged from the shell through the manifold.

[0023] Preferably, the shell-side internals include a liner and a liner diameter-reducing section. The liner maintains a gap with the shell-side cylinder. One end of the liner diameter-reducing section is connected to the liner, and the other end extends radially to the shell-side cylinder. The side of the liner closest to the tube sheet maintains a distance from the tube sheet so that the first fluid flows through the gap to the annular flow channel.

[0024] The liner and the liner reducer section are sealed and fixedly connected; they can be integrally molded or fixed by welding. The liner maintains a gap with the shell-side body, and the suspended end of the liner has a gap with the tube sheet to allow fluid to flow through this gap to the annular flow channel. The end of the liner reducer section extends into the shell-side body and is sealed to the inner wall of the shell-side body, providing space for connection and installation of the liner connecting pipe and the annular flow channel.

[0025] Preferably, the heat exchanger tube assembly includes heat exchanger tubes and air guide tubes connected to the heat exchanger tubes, and multiple sets of air guide tubes are connected to the collection tube assembly.

[0026] The heat exchange tubes are small and thin tubes. The second fluid in multiple sets of heat exchange tubes is collected and flows to the gas guide tube. The second fluid passes through multiple sets of gas guide tubes and is further collected to the collection tube assembly before being discharged from the shell.

[0027] Preferably, the heat exchange tubes are uniformly distributed in a ring shape.

[0028] The first embodiment of the heat exchange tube arrangement is that the heat exchange tubes are evenly distributed in a ring shape. This arrangement makes the small tubes of the heat exchange tubes compact and can make full use of the space of the tube sheet and the liner.

[0029] Preferably, the heat exchange tubes are evenly distributed in a dotted pattern.

[0030] The second embodiment of the heat exchange tube arrangement is that the heat exchange tubes are evenly distributed in a dotted pattern. In this arrangement, the dots are composed of multiple sets of small and thin heat exchange tubes. The spaces between the dots are relatively large, which is beneficial for equipment maintenance and provides greater operational flexibility.

[0031] Preferably, the heat exchange tubes are distributed in a combination of annular and dotted patterns.

[0032] The third embodiment of heat exchanger tube layout is a combination of ring and dot distribution. This layout combines the characteristics of ring and dot distribution, which is convenient for maintenance and can make effective use of space.

[0033] Preferably, a semi-circular pipe is provided at the end of the gas guide pipe near the heat exchange tube, and a small loop plate is provided on the semi-circular pipe, which is connected to the heat exchange tube.

[0034] The specific connection structure is illustrated using a first embodiment of the heat exchanger tube arrangement. A semi-circular tube is provided at the end of the gas guide pipe, connecting the uniformly distributed annular heat exchanger tubes together. A small annular tube sheet is also provided on the semi-circular tube to connect the heat exchanger tubes, such that one end of the heat exchanger tube is connected to the tube sheet, and the other end is connected to the small annular tube sheet. Because the small annular tube sheet has a small structure, even if it comes into contact with the uncooled initial fluid, placing it in a high-temperature environment, its material is selectable.

[0035] Preferably, the collection tube assembly includes a main collection tube and a second fluid collection inlet disposed on one side of the main collection tube, the second fluid collection inlet being connected to the air guide tube.

[0036] The second fluid collection inlet is set up to connect the main collection pipe and the air guide pipe. The inner diameter of the second fluid collection inlet matches the inner diameter of the air guide pipe.

[0037] Preferably, a filling layer is provided between the main collection pipe and the tube sheet.

[0038] The medium flowing inside the main collection pipe is the second fluid that has been heated by heat exchange. The area where the outer wall of the main collection pipe contacts the tube sheet is filled with a filling layer to isolate the heat of the outer wall of the main collection pipe from the tube sheet, thereby better protecting the tube sheet.

[0039] Preferably, the main collection pipe and the tube sheet are located at the connection point inside the tube box. A first expansion joint is provided on the outside of the main collection pipe. One side of the first expansion joint is fixedly connected to the tube sheet, and the other side is fixedly connected to the outer wall of the main collection pipe.

[0040] The first expansion joint is installed outside the main collection pipe, with one side fixedly connected to the tube sheet and the other side fixedly connected to the outer wall of the main collection pipe, thus achieving a sealing between the tube sheet and the main collection pipe and preventing the first fluid and the second fluid from mixing. At the same time, when the main collection pipe expands and elongates due to the influence of the second fluid after heat exchange and heating, the first expansion joint can elongate along with the deformation and elongation of that section of the main collection pipe. After the equipment is shut down, when the main collection pipe recovers its deformation due to the absence of high temperature, the first expansion joint can shorten along with the recovery of the deformation of that section of the main collection pipe.

[0041] Preferably, a tube box end cap is provided at the end of the tube box body away from the tube sheet, the main collection tube extends out of the shell through the tube box end cap, and a second expansion joint is provided on a section of the main collection tube inside the tube box end cap.

[0042] In order to further absorb the deformation caused by the second fluid after the heat exchange and heating, a second expansion joint is provided in a section of the main collection pipe inside the tube box head to reduce the deformation of the main collection pipe itself and protect it.

[0043] The second aspect of this invention provides a method of using a shell-and-tube heat exchanger. In this shell-and-tube heat exchanger, the first fluid flows through the shell side, and the second fluid flows through the tube side. The specific operating steps are as follows:

[0044] S01. When the equipment needs to be started, steam is introduced from the tube side to preheat the equipment.

[0045] S02. The second fluid medium is introduced into the pipe side and the medium delivery is stabilized.

[0046] S03. Slowly introduce the first fluid medium into the shell side;

[0047] S04. When the outlet temperature of the tube-side medium does not reach the predetermined value, adjust the regulating component of the shell side to control the flow rate of the first fluid until the outlet temperature of the tube-side medium reaches the predetermined value.

[0048] S04. When the equipment needs to be stopped, slowly stop the delivery of the medium to the shell side until the delivery of the shell side medium stops completely.

[0049] S05. Slowly stop supplying the medium to the pipe side until the medium supply to the pipe side completely stops.

[0050] It is important to note that the shell-side medium cannot be introduced alone. Since the shell-side medium is at a relatively high temperature, direct introduction would place the entire equipment in a high-temperature, high-pressure environment, which would easily damage the equipment. The tube side must be preheated with steam first. After preheating, the tube-side medium should be introduced first, and only after the tube-side medium has stabilized can the shell-side medium be introduced. Preheating the tube side with steam is necessary to avoid damage caused by a strong temperature difference when directly introducing the tube-side medium.

[0051] The beneficial effects of the shell-and-tube heat exchanger of the present invention, achieved through the above technical solution, are as follows:

[0052] First, by setting a reasonable flow channel structure, it can be preferentially applied to situations where both the tube and shell sides are at high temperature and high pressure, and can also be applied to medium-pressure and low-pressure steam superheating situations.

[0053] Secondly, both the tube side and shell side contain high-temperature and high-pressure media, but both sides of the tube sheet are in a non-high-temperature environment. The tube sheet design temperature can be set at a lower design temperature, which allows for the selection of tube sheet materials. At the same time, it reduces the weight of the equipment and saves costs.

[0054] Third, although both the tube side and shell side contain high-temperature and high-pressure media, the shell-side cylinder and end caps, as well as the tube box cylinder and end caps, are located in non-high-temperature environments. Therefore, the design temperature of the shell-side cylinder and end caps, and the tube box cylinder and end caps can be set at a lower design temperature, allowing for selection of materials for these components. This also reduces equipment weight and saves costs.

[0055] Fourth, the tube sheet of the heat exchanger is in a non-high-temperature environment, which can greatly reduce the thermal stress of the tube sheet and the thermal stress of the tube joints, reduce the risk of tube joint leakage, and enable the equipment to operate safely and stably for a long time.

[0056] Fifth, the tube sheet on the left side of the heat exchanger is composed of several small ring tube sheets. The small ring tube sheet structure is relatively small, and the design of the small ring tube sheet greatly reduces the calculated diameter of the tube sheet. The thickness of the small ring tube sheet can be greatly reduced, allowing for the selection of suitable materials and saving costs.

[0057] Sixth, the heat exchanger is equipped with a collection pipe assembly. The main collection pipe is connected to the tube sheet through an expansion joint. The main collection pipe can expand freely in the axial direction, which effectively reduces the thermal stress of the main collection pipe and improves the safety of equipment operation.

[0058] Seventh, by setting an adjustment component inside the shell, the drawback of the equipment not being adjustable is solved, making the equipment safer to operate and its application range wider and more stable. Attached Figure Description

[0059] Figure 1This is a schematic diagram of the overall structure of a shell-and-tube heat exchanger.

[0060] Figure 2 This is a schematic diagram of the liner and outer shell structure of a shell-and-tube heat exchanger.

[0061] Figure 3 This is a schematic diagram of the AA cross-section structure of the first embodiment of the heat exchange tube layout of a shell-and-tube heat exchanger;

[0062] Figure 4 This is a schematic diagram of the AA section structure of the second embodiment of the heat exchange tube layout of the shell-and-tube heat exchanger;

[0063] Figure 5 This is a schematic diagram of the AA section structure of the third embodiment of the heat exchange tube layout of the shell-and-tube heat exchanger;

[0064] Figure 6 This is a schematic diagram of the BB cross-section structure of the connecting pipe between the regulating component and the liner;

[0065] Figure 7 This is a partial structural diagram of the first two sets of heat exchange tube assemblies;

[0066] Figure 8 This is a schematic diagram of the first two sets of heat exchange tube assemblies from a C-direction perspective.

[0067] Figure 9 This is a partial structural diagram of the second two-group heat exchanger tube assembly;

[0068] Figure 10 This is a schematic diagram of the second two-group heat exchange tube assembly from the D-direction perspective.

[0069] Figure 11 This is an enlarged partial structural diagram of the collecting tube assembly;

[0070] Figure 12 This is a magnified partial structural diagram of the adjustment component;

[0071] Figure 13 This is a structural schematic diagram of an existing fixed tubesheet heat exchanger design;

[0072] Figure 14 This is a schematic diagram of an existing fixed tube sheet heat exchanger with an added bypass.

[0073] Explanation of reference numerals in the attached figures

[0074] 1. Fixed tube sheet heat exchanger; 101. First gas inlet; 102. First gas outlet; 103. Second gas inlet; 104. Second gas outlet; 11. Shell-side structure; 111. Front tube sheet; 112. Rear tube sheet; 113. Front tube box; 114. Rear tube box; 12. Heat exchange tubes; 13. First baffle; 14. First gas flow direction; 15. Second gas flow direction; 16. Bypass; 161. Bypass valve; 2. Shell-and-tube heat exchanger; 201. First fluid inlet; 202. First fluid outlet; 203. Second fluid inlet; 204. Second fluid outlet; 21. Shell; 211. Shell-side shell; 2111. Pressure-bearing shell; 2112. Insulation layer; 212. Tube box shell; 22. Heat exchange tube assembly; 221. Gas guide tube. ; 222, Semi-annular tube; 223, Small annular tube sheet; 224, Heat exchange tube; 23, Annular flow channel; 24, Tube sheet; 25, Tube box end cap; 26, Regulating assembly; 261, Liner connecting pipe; 262, Manifold; 263, Connecting pipe; 264, Valve; 265, Valve stem; 266, Actuator; 27, Shell-side internals; 271, Liner; 272, Liner reducing section; 28, Collecting pipe assembly; 281, Tube cap; 282, Second fluid collection inlet; 283, Main collecting pipe; 284, First expansion joint; 285, Second expansion joint; 29, Packing layer; 210, Second baffle; 3, First fluid flow direction; 4, Second fluid flow direction; N1, High-temperature synthesis gas; N2, Low-temperature synthesis gas; N3, Low-temperature saturated steam; N4, High-temperature superheated steam. Detailed Implementation

[0075] The specific embodiments of the invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the invention.

[0076] In this invention, unless otherwise stated, directional terms such as "up, down, left, right, inside, outside, far, near, front" are generally used to refer to the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and therefore should not be construed as limiting this invention.

[0077] To address the problems encountered in the prior art, this application provides a shell-and-tube heat exchanger, such as... Figure 1 and Figure 2 As shown, it includes a housing 21 and a tube sheet 24 disposed inside the housing 21. The tube sheet 24 divides the housing 21 into a shell-side cylinder 211 and a tube box cylinder 212. A first fluid inlet 201 is provided on the side of the shell-side cylinder 211 away from the tube sheet 24.

[0078] The shell-side cylinder 211 has a gap along its inner wall and is provided with a shell-side inner member 27. The shell-side inner member 27 is hollow and open at both ends. One end of the shell-side inner member 27 near the tube sheet 24 is suspended, and the other end extends radially to the inner wall of the shell-side cylinder 211 and is sealed to the inner wall of the shell-side cylinder 211 to form an annular flow channel 23.

[0079] The portion of the shell-side cylindrical body 211 away from the shell-side internals 27 is a heat-insulated pressure-bearing shell 2111. The regulating component 26 is disposed inside the pressure-bearing shell 2111. The regulating component 26 is connected to the pressure-bearing shell 2111 through the regulating parts to control the fluid flow rate. The regulating component 26 is also connected to the annular flow channel 23. The outlet of the regulating component 26 extends out of the shell-side cylindrical body 211 to form a first fluid outlet 202.

[0080] The tube box body 212 is provided with a second fluid inlet 203. The tube sheet 24 is fitted with a heat exchange tube assembly 22 and a collection tube assembly 28, both of which extend into the shell-side inner part 27. The collection tube assembly 28 is located on one side of the shell-side inner part 27 and communicates with the heat exchange tube assembly 22. The other side extends out of the shell 21 to form a second fluid outlet. The side of the heat exchange tube assembly 22 near the tube box body 212 communicates with the tube box body 212.

[0081] Specifically, such as Figure 2 As shown, the shell 21 of the shell-and-tube heat exchanger 2 includes a shell-side cylindrical body 211 and a tube box cylindrical body 212. The two spaces are isolated by a tube sheet 24, and related structural arrangements allow the shell-and-tube heat exchanger 2 to have both shell-side and tube-side flow path structures. The first fluid flows through the shell side, and the second fluid flows through the tube side.

[0082] The specific settings of the above-mentioned related structures are as follows: Figure 2 As shown, the side of the shell-side cylinder 211 away from the tube sheet 24, i.e. Figure 2 The shell-side cylindrical body 211 shown has a first fluid inlet 201 on its leftmost side for introducing a first fluid medium. The shell-side cylindrical body 211 includes a pressure-bearing shell section 2111 and a normal shell section.

[0083] The pressure-bearing shell 2111 is located immediately adjacent to the first fluid inlet 201, such as... Figure 2 As shown, the heat insulation of the pressure shell 2111 can be provided by setting a heat insulation layer 2112 on the inner wall of the pressure shell 2111. The heat insulation layer 2112 can be a cast heat insulation material, preferably a refractory material. The heat insulation layer 2112 can better protect the pressure shell 2111, so that the pressure shell 2111 section inside the shell side cylinder 211 can withstand high temperature and high pressure working conditions.

[0084] Shell-side internals 27 are provided within the ordinary shell section of the shell-side cylindrical body 211, such as... Figure 2 As shown, the shell-side internal component 27 has an internal cavity structure with open ends. The open cavity of the shell-side internal component 27 is arranged along the inner wall of the shell-side cylinder 211, and there is a certain gap between the shell-side internal component 27 and the inner wall of the shell-side cylinder 211, which is the annular flow channel 23. One end of the shell-side internal component 27 is connected to the inner wall of the shell-side cylinder 211, and the other end is suspended from the inner wall of the shell-side cylinder 211. The end of the shell-side internal component 27 near the tube sheet 24 is suspended, and the cavity of the shell-side internal component 27 extends radially circumferentially to the inner wall of the shell-side cylinder 211 at the end near the pressure-bearing shell 2111, and is sealed to the inner wall of the shell-side cylinder 211, thereby forming the annular flow channel 23 between the shell-side cylinder 211 and the shell-side internal component 27. The side of the shell-side internal component 27 near the tube sheet 24 maintains a certain distance from the tube sheet 24, which is sufficient to allow smooth fluid flow.

[0085] like Figure 1 and Figure 12 As shown, an adjustment assembly 26 is provided inside the pressure-bearing shell 2111. The adjustment assembly 26 is connected to both the pressure-bearing shell 2111 section and the annular flow channel 23. The flow rate of the first fluid medium delivered from the pressure-bearing shell 2111 to the adjustment assembly 26 can be controlled by the adjustment assembly. The adjustment assembly 26 also has an outlet, with one end extending out of the shell-side cylinder 211 to form a first fluid outlet 202.

[0086] The first fluid medium enters through the first fluid inlet 201, passes through the internal space of the pressure-bearing shell 2111, and then enters from the end of the shell-side inner member 27 near the pressure-bearing shell 2111. Within the shell-side inner member 27, it exchanges heat with the second fluid medium in the tube side and then exits from the end of the shell-side inner member 27 near the tube sheet 24, being transported to the annular flow channel 23. The first fluid medium in the annular flow channel 23 then flows into the regulating assembly 26, where it mixes with the unheated first fluid medium flowing into the regulating assembly 26 from the pressure-bearing shell 2111. Finally, it exits from the first fluid outlet 202. This forms the shell side through which the first fluid medium flows.

[0087] like Figure 1 and Figure 2 As shown, a heat exchange tube assembly 22 and a collection tube assembly 28 are inserted into the tube sheet 24. Both the heat exchange tube assembly 22 and the collection tube assembly 28 extend into the cavity of the shell-side inner part 27, as shown. Figure 1As shown, the heat exchange tube assembly 22 and the collecting tube assembly 28 extend away from the tube sheet 24 and into the cavity of the shell-side internals 27. At the ends of the heat exchange tube assembly 22 and the collecting tube assembly 28 away from the tube sheet 24, one side of the heat exchange tube assembly 22 communicates with the collecting tube assembly 28, while the other side of the collecting tube assembly 28 extends out of the shell 21. It should be noted that one end of the heat exchange tube assembly 22 communicates with the internal space of the tube box 212, and the other end communicates with the collecting tube assembly 28. The end of the collecting tube assembly 28 away from the heat exchange tube assembly 22 extends all the way to the outside of the shell 21. A second fluid inlet 203 is also provided on the tube box 212. This allows the second fluid to enter the tube box 212 from the outside through the second fluid inlet 203, flow through the heat exchange tube assembly 22, collect in the collecting tube assembly 28, and be discharged outside the shell 21 through the collecting tube assembly 28, thus forming the tube side of the second fluid medium flow path.

[0088] like Figure 1 and Figure 2 The diagram shows the first fluid flow direction 3 and the second fluid flow direction 4. The first fluid enters the pressure-bearing shell section 2111 of the shell-side cylinder 211 through the first fluid inlet 201, and then flows into the cavity of the shell-side inner member 27. After heat exchange with the second fluid in the heat exchange tube assembly 22 inside the cavity of the shell-side inner member 27, the first fluid flows into the annular flow channel 23 formed between the shell-side inner member 27 and the shell-side cylinder 211, and is then transported from the annular flow channel 23 to the regulating assembly 26. In the regulating assembly 26, the fluid flows through the pressure-bearing shell section 2111. After the first fluid medium that has not undergone heat exchange is mixed with the regulating component 26, it is discharged from the first fluid outlet 202 extending from the regulating component 26 into the shell-side cylinder 211; the second fluid medium is introduced into the tube box cylinder 212 through the second fluid inlet 203 on the tube box cylinder 212, flows into the heat exchange tube assembly 22 on the tube sheet 24, and exchanges heat with the first fluid medium in the cavity area of ​​the shell-side inner part 27. The heat-exchanged second fluid is collected in the collection tube assembly 28 and discharged to the outside of the shell 21 through the collection tube assembly 28.

[0089] When the first fluid medium is a relatively high-temperature and high-pressure fluid, and the second fluid medium is a relatively low-temperature and high-pressure fluid, the tube sheet 24, on the side closer to the shell-side cylinder 211, contacts the relatively low-temperature and high-pressure first fluid medium after heat exchange and cooling, while the side closer to the tube box cylinder 212 contacts the relatively low-temperature and high-pressure second fluid medium that has just been introduced and has not yet undergone heat exchange. Since neither side of the tube sheet 24 structure comes into contact with the high-temperature and high-pressure fluid, it provides better protection for the tube sheet 24 structure. This allows for greater choice in manufacturing materials even for larger-sized tube sheet 24 structures due to the reduced environmental conditions. Furthermore, the shell-and-tube heat exchanger 2 of this application only requires one set of large-sized tube sheets 24, reducing the overall weight of the equipment and lowering costs.

[0090] On the other hand, a thermometer is installed on the pipeline at the second fluid outlet 204 to measure the outlet temperature of the second fluid. If the input of the first fluid experiences load regulation or fluid fluctuations, causing the outlet temperature of the second fluid to change and fall outside the preset threshold, the regulating component of the regulating assembly 26 located inside the shell-side cylinder 211 can be operated to allow a portion of the first fluid medium to bypass the shell side and be directly delivered to the regulating assembly 26, ultimately mixing with the first fluid after heat exchange from the annular flow channel 23 before flowing out of the equipment. It should be noted that by increasing or decreasing the flow rate of the first fluid flowing through the cavity inside the shell-side internals 27 and outside the heat exchange tube assembly 22, the outlet temperature of the second fluid can be raised or lowered, thereby achieving an adjustable function for the temperature of the discharged second fluid. At the same time, the fluid inside the regulating assembly 26 consists of a mixture of the first fluid after heat exchange and a small amount of the first fluid that has not undergone heat exchange. The overall temperature value of the fluid inside the regulating assembly 26 tends to be closer to the temperature value of the first fluid after heat exchange, thus allowing the regulating assembly 26 to avoid being subjected to a relatively high-temperature and high-pressure fluid environment, and making the material of the regulating assembly 26 more selective.

[0091] Furthermore, the regulating component 26 includes two sets of inlets and one set of outlets. Multiple sets of liner connecting pipes 261 can be provided. Multiple sets of liner connecting pipes 261 converge into a manifold 262 to form a first set of inlets. The internal space of the pressure-bearing housing 2111 is connected to the manifold 262 to form a second set of inlets. The manifold 262 is connected to the outside of the housing 21 to form a set of outlets. The flow rate of fluid flowing in through the second set of inlets is adjustable.

[0092] like Figure 12As shown, the regulating component 26, as a connecting structure, has the function of collecting fluid and then discharging the collected fluid. The regulating component 26 is provided with two sets of inlets and one set of outlets. The liner connecting pipe 261 is preferably provided in multiple sets. Specifically, the regulating component 26 includes a manifold 262, a liner connecting pipe 261, and a connecting pipe 263. Among them, multiple sets of liner connecting pipes 261 can be provided, and multiple sets of liner connecting pipes 261 are connected to the manifold 262 to form the first set of inlets. The connecting pipe 263 is connected to the internal space of the pressure-bearing shell 2111, and the connecting pipe 263 is connected to the manifold 262 to form the second set of inlets. An regulating component is provided at the inlet of the connecting pipe 263, and the flow rate of the fluid flowing from the connecting pipe 263 to the manifold 262 can be controlled by the regulating component. The manifold 262 is provided with an outlet pipe that extends out of the shell 21 and is connected to the external space of the shell 21 to form a set of outlets.

[0093] The two inlets of the regulating component 26 can respectively introduce the first fluid, which has been cooled by heat exchange and flows through the annular channel 23, and the first high-temperature fluid that has not undergone heat exchange, which flows from the pressure shell 2111. The two fluids are mixed in the manifold 262, and one outlet can discharge the mixed fluid in the manifold 262 to the outside of the shell 21. The manifold 262 collects and discharges the fluid, providing a space for the collection and discharge of the fluid.

[0094] Furthermore, the manifold 262 is an annular pipe, and the connecting pipe 263 is connected to the manifold 262 to form a second set of inlets. The regulating components include a valve 264, a valve stem 265, and an actuator 26. The valve 264 is located at the inlet of the connecting pipe 263, and the valve stem 265 connected to the valve 264 extends out of the housing 21 and is connected to the actuator 266.

[0095] like Figure 6 As shown, the manifold 262, as a collecting pipe, can be of various structures, preferably a ring pipe structure. The specific method by which the manifold 262 connects to the pressure-bearing shell 2111 is as follows... Figure 12As shown, a connecting pipe 263 is also provided on the manifold 262, and the connection between the pressure-bearing housing 2111 and the manifold 262 is achieved through the connecting pipe 263 to form a second set of inlets. A regulating component consisting of a valve 264, a valve stem 265, and an actuator 266 can regulate the flow rate of fluid entering the manifold 262 through the second set of inlets. Specifically, placing the valve 264 at the inlet of the connecting pipe 263 allows for flow control of the fluid flowing into the manifold 262 through the connecting pipe 263. The valve stem 265 is connected to the valve 264 and extends outside the housing 21 to connect with the actuator 266. Through the connection between the valve stem 265 and the valve 264, the actuator 266 controlling the valve 264 can be located outside the housing 21, facilitating manual operation to control the flow rate of fluid entering the connecting pipe 263 from within the pressure-bearing housing 2111. The valve 264 is preferably a high-temperature regulating valve. Since the actuator 266 of the valve 264 is existing technology, it will not be described in detail here.

[0096] Furthermore, one end of the liner connecting pipe 261 is connected to the annular flow channel 23, and the other end is connected to the manifold pipe 262.

[0097] like Figure 1 and Figure 6 As shown, both ends of the bushing connecting pipe 261 are connected to the annular flow channel 23 and the manifold 262, respectively. Specifically, one end of multiple sets of bushing connecting pipes 261 can be circumferentially and evenly distributed in the manifold 262 and connected to it. The connection method between the bushing connecting pipes 261 and the manifold 262 facilitates the flow of fluid from the annular flow channel 23 into the manifold 262. The other end of the bushing connecting pipe 261 is connected to the annular flow channel 23, so that the fluid in the annular flow channel 23 flows out into the manifold 262.

[0098] The annular flow channel 23 is annular, and the manifold 262 is also annular. Multiple sets of bushing connecting pipes 261 are provided to introduce the fluid from the annular flow channel 23 into the manifold 262. The bushing connecting pipes 261 can be evenly distributed around the manifold 262 so that the fluid in the annular flow channel 23 can flow quickly into the manifold 262 and be discharged from the shell through the manifold 262.

[0099] Furthermore, the shell-side internals 27 include a liner 271 and a liner diameter-changing section 272. The liner 271 maintains a gap with the shell-side cylinder 211. One end of the liner diameter-changing section 272 is connected to the liner 271, and the other end extends circumferentially and radially to the shell-side cylinder 211. The side of the liner 271 near the tube sheet 24 maintains a distance from the tube sheet 24 so that the first fluid flows through the gap to the annular flow channel 23.

[0100] like Figure 2As shown, the cavity of the shell-side internal component 27 includes a liner 271 and a liner reducing section 272. One end of the liner reducing section 272 is connected to the liner 271, and the other end is connected to the shell-side cylindrical body 211. The liner 271 and the liner reducing section 272 can be fixedly connected; they can be integrally formed or sealed and fixed by welding. A gap is maintained between the liner 271 and the inner wall of the shell-side cylindrical body 211 to form an annular flow channel 23, and the suspended end of the liner 271 is spaced from the tube sheet 24 to allow fluid to flow through the gap into the annular flow channel 23. The end of the liner reducing section 272 away from the liner 271 extends to the inner wall of the shell-side cylindrical body 211 and is sealed to the inner wall of the shell-side cylindrical body 211, so that the liner connecting pipe 261 and the annular flow channel 23 have connection and installation space. Meanwhile, the connection between the liner variable diameter section 272 and the shell side cylinder 211 is preferably in contact with the pressure-bearing shell 2111, so that the ordinary cylinder section of the shell side cylinder 211 does not come into contact with the first fluid before heat exchange and cooling, thereby better protecting the shell side cylinder 211 and extending the service life of the shell 21.

[0101] Furthermore, the heat exchange tube assembly 22 includes a heat exchange tube 224 and a gas guide tube 221 connected to the heat exchange tube 224, and multiple gas guide tubes 221 are connected to the collection tube assembly 28.

[0102] like Figure 1 , Figure 7 and Figure 9 As shown, the heat exchange tube assembly 22 includes heat exchange tubes 224 and a gas guide pipe 221. The heat exchange tubes 224 are thin tubes, and a second fluid medium introduced from the tube box body 212 flows through their inner walls. The gas guide pipe 221 is connected to the heat exchange tubes 224, and the second fluid medium from multiple sets of heat exchange tubes 224 converges and flows into the gas guide pipe 221. The collecting pipe assembly 28 is connected to the gas guide pipe 221, and the second fluid medium from multiple sets of gas guide pipes 221 further converges into the collecting pipe assembly 28, and is discharged to the outside of the shell 21 through the collecting pipe assembly 28.

[0103] Furthermore, the heat exchange tubes 224 are uniformly distributed in a ring shape.

[0104] The heat exchange tubes 224 are evenly distributed in a ring shape, which is the first embodiment of the heat exchange tube 224 arrangement. Figure 3 As shown, the heat exchange tubes 224 are evenly distributed in a ring shape on the tube sheet 24, and multiple sets of rings are evenly arranged. This tube arrangement makes the arrangement of the small tubes of the heat exchange tubes 224 compact, which can make full use of the space of the tube sheet 24 and the liner 271 that houses the heat exchange tube assembly 22.

[0105] Furthermore, the heat exchange tubes 224 are evenly distributed in a dotted pattern.

[0106] The second embodiment of the heat exchange tube arrangement is that the heat exchange tubes 224 are evenly distributed in a dotted pattern. Figure 4 As shown, the heat exchange tubes 224 are evenly distributed on the tube sheet 24 in a point-like pattern, consisting of multiple sets of small tubes 224. This tube arrangement allows for greater space between the point-like areas, enabling the tubes 224 to be blocked at these point-like locations when problems occur. The blocked area has a smaller impact area, providing more operational space for equipment maintenance and offering greater flexibility in operation.

[0107] Furthermore, the heat exchange tubes 224 are distributed in a combination of annular and dotted patterns.

[0108] The heat exchange tubes 224 are distributed in a combination of ring and regional point patterns, which is the third embodiment of the heat exchange tube 224 arrangement. Figure 5 As shown, this tube arrangement combines the features of a ring-shaped arrangement and a regional point-shaped distribution, which is convenient for maintenance, has a small impact area on the sealing when the heat exchange tube 224 has a problem, and can also effectively utilize the space of the tube sheet 24 and the liner 271.

[0109] Furthermore, a semi-circular pipe 222 is provided at the end of the air guide pipe 221 near the heat exchange pipe 224, and a small loop plate 223 is provided on the semi-circular pipe 222, which is connected to the heat exchange pipe 224.

[0110] Specifically, the specific connection structure of the heat exchanger tube assembly 22 will be described using a first embodiment of the heat exchanger tube 224 arrangement. For example... Figure 7 and Figure 9 As shown, a semi-circular tube 222 is provided at the end of the air guide tube 221 to connect the uniformly distributed annular heat exchange tubes 224 together. A small annular tube plate 223 is also provided on the semi-circular tube 222 to connect the heat exchange tubes 224, so that one end of the heat exchange tube 224 is connected to the tube plate 24 and the other end is connected to the small annular tube plate 223.

[0111] It should be noted that although the small loop tube sheet 223 needs to be in contact with the first fluid medium before heat exchange, the small loop tube sheet 223 has a small inner diameter and thickness, which makes the material of the small loop tube sheet 223 still selective when facing a relatively high temperature fluid medium.

[0112] Furthermore, the collection tube assembly 28 includes a main collection tube 283 and a second fluid collection inlet 282 disposed on one side of the main collection tube 283, the second fluid collection inlet 282 being connected to the air guide tube 221.

[0113] Specifically, such as Figure 1 and 11As shown, the collection pipe assembly 28 includes a main collection pipe 283 and a second fluid collection inlet 282. The end of the main collection pipe 283 within the liner 271 requires a cap 281 to seal one side of the main collection pipe 283. The second fluid collection inlet 282 can be circumferentially and evenly distributed on the main collection pipe 283, and is fixedly and sealingly connected to the main collection pipe 283. This fixed connection can be integrally formed or welded. It is important to note that the inner diameter of the second fluid collection inlet 282 matches the inner diameter of the air guide pipe 221, allowing for better and more stable communication between the main collection pipe 283 and the air guide pipe 221.

[0114] Furthermore, a filling layer 29 is provided between the main collection pipe 283 and the pipe plate 24.

[0115] like Figure 11 As shown, a filler layer 29 is filled between the main collection pipe 283 and the tube sheet 24. The filler layer 29 is preferably made of ceramic fiber. The medium flowing in the main collection pipe 283 is a second fluid that has been heated by heat exchange. The filler layer 29 fills the area where the outer wall of the main collection pipe 283 contacts the tube sheet 24, which can prevent the temperature of the outer wall of the main collection pipe 283 from being transferred to the tube sheet 24, thereby better protecting the tube sheet 24 and extending its service life.

[0116] Furthermore, the main collection pipe 283 and the pipe plate 24 are located at the connection point inside the pipe box cylinder 212. A first expansion joint 284 is provided on the outside of the main collection pipe 283. One side of the first expansion joint 284 is fixedly connected to the pipe plate 24, and the other side is fixedly connected to the outer wall of the main collection pipe 283.

[0117] Specifically, such as Figure 1 and Figure 11 As shown, a first expansion joint 284 is provided at the connection between the main collection pipe 283 and the tube sheet 24. This first expansion joint 284 is located at the connection between the main collection pipe 283 and the tube sheet 24 within the tube housing 212. Specifically, the first expansion joint 284 is positioned outside the main collection pipe 283. One side of the first expansion joint 284 is fixedly and sealed to the tube sheet 24, and the other side is fixedly and sealed to the outer wall of the main collection pipe 283. This achieves a sealed connection between the tube sheet 24 and the main collection pipe 283, preventing the first and second fluids from mixing through the gaps in the filling layer. Simultaneously, when the main collection pipe 283 expands and elongates due to the influence of the second fluid after heat exchange and temperature rise, the first expansion joint 284 can elongate along with the deformation of that section of the main collection pipe 283. After the equipment is shut down, when the main collection pipe 283 recovers its deformation without being affected by high temperatures, the first expansion joint 284 can shorten along with the recovery of that section of the main collection pipe 283.

[0118] Furthermore, a tube box end cap 25 is provided at the end of the tube box body 212 away from the tube sheet 24, and the main collection tube 283 extends out of the shell 21 through the tube box end cap 25. A second expansion joint 285 is provided on a section of the main collection tube 283 inside the tube box end cap 25.

[0119] like Figure 1 , Figure 2 and Figure 11 As shown, a tube box end cap 25 is provided at the end of the tube box body 212 away from the tube sheet 24, and a second fluid outlet 204 is also provided on the tube box end cap 25. After passing through the tube sheet 24, the main collection pipe 283 passes through the tube box body 212 and the tube box end cap 25, and finally extends out of the shell 21 through the second fluid outlet 204. The medium flowing in the main collection pipe 283 is the second fluid after heat exchange and heating, therefore, the main collection pipe 283 is very prone to expansion and deformation. In order to further absorb the deformation of the main collection pipe 283 caused by the second fluid after heat exchange and heating, a second expansion joint 285 is provided at one section of the main collection pipe 283 inside the tube box end cap 25. The second expansion joint 285 can reduce the deformation of the main collection pipe 283 itself and protect the main collection pipe 283.

[0120] It should be noted that the second expansion joint 285 is completely different from the first expansion joint 284. The second expansion joint 285 replaces a section of the main collection pipe 283; that is, this section is a single-layer pipe section, which only has the second expansion joint 285 and does not have the main collection pipe 283. Specifically, both ends of the second expansion joint 285 are fixedly connected to the main collection pipe 283, and the fixed connection can be welded.

[0121] It should be noted that the heat exchanger tube assemblies 22 are provided with evenly distributed and staggered second baffles 210, such as... Figure 1 In the embodiment of the four-group annularly distributed heat exchange tube assembly 22 shown, the first fluid flow direction 3 is as indicated by the hollow arrow. The setting of the second baffle 210 allows the first fluid medium to exchange heat more thoroughly with the second fluid medium in the area of ​​the liner 271, thereby improving the heat exchange efficiency of the two media.

[0122] The present invention also provides a method for operating a shell-and-tube heat exchanger 2. Using the aforementioned shell-and-tube heat exchanger 2, the first fluid flows through the shell side, and the second fluid flows through the tube side. The specific operating steps are as follows:

[0123] S01. When the equipment needs to be started, steam is introduced from the tube side to preheat the equipment.

[0124] S02. The second fluid medium is introduced into the pipe side and the medium delivery is stabilized.

[0125] S03. Slowly introduce the first fluid medium into the shell side;

[0126] S04. When the outlet temperature of the tube-side medium does not reach the predetermined value, adjust the regulating component of the shell side to control the flow rate of the first fluid until the outlet temperature of the tube-side medium reaches the predetermined value.

[0127] S04. When the equipment needs to be stopped, slowly stop the delivery of the medium to the shell side until the delivery of the shell side medium stops completely.

[0128] S05. Slowly stop supplying the medium to the pipe side until the medium supply to the pipe side completely stops.

[0129] It is important to note that the shell-side medium should not be introduced first. Since the shell-side medium is at a relatively high temperature, directly introducing it would place the entire equipment in a high-temperature, high-pressure environment, which could easily damage the equipment. The tube side must be preheated with steam first. After preheating, the tube-side medium should be introduced first, and only after the tube-side medium has stabilized should the shell-side medium be introduced. Preheating the tube side with steam is crucial to avoid damage caused by a significant temperature difference when directly introducing the tube-side medium.

[0130] Example 1:

[0131] In a certain chemical plant, the high-temperature syngas generated after the reactor reaction has a temperature of 5.0 MPaG@650℃ ("@" and "and" have the same meaning, the same below). Simultaneously, the waste heat boiler in the plant produces saturated steam at 11.0 MPaG@318℃, and the superheated steam temperature in the plant's utilities is T=525℃. Therefore, a heat exchanger is needed to reduce the saturated steam from the waste heat boiler (11.0 MPaG@318℃) to 525℃, while simultaneously lowering the high-temperature syngas to approximately 400℃ for use by downstream units.

[0132] For example, using a conventionally designed fixed tubesheet heat exchanger 1 Figure 13 As shown, the design of adding bypass 16 is as follows, in cases where the high-temperature syngas feed is unstable. Figure 14As shown, the front tube sheet 111, located on the shell-side structure 11, needs to withstand superheated steam at 11.0 MPaG@525℃, while the front tube sheet 111, located on the front tube box 113, needs to withstand syngas at 5.0 MPaG@650℃. This means the front tube sheet 111 must simultaneously withstand both superheated steam at 11.0 MPaG@525℃ and syngas at 5.0 MPaG@650℃. Since suitable materials cannot be found, the traditionally designed fixed tube sheet heat exchanger 1 is no longer suitable for this process environment. Furthermore, in the fixed tube sheet heat exchanger 1 with the added bypass 16, the bypass 16 structure also needs to fully withstand the high-temperature syngas at 5.0 MPaG@650℃. Since suitable materials cannot be found for the bypass 16 structure, a bypass design is not feasible. This makes it impossible to control the temperature of the second gas discharged from the second gas outlet 104 in the fixed tube sheet heat exchanger 1.

[0133] To address the problems associated with traditional designs, a shell-and-tube heat exchanger 2 is provided, such as... Figure 1 and Figure 2 As shown, the first fluid medium is high-temperature synthesis gas at 5.0 MPaG@650℃, and the second fluid medium is saturated steam at 11.0 MPaG@318℃. The flow direction of the first fluid is as shown in Figure 3. Figure 1 As shown by the hollow arrow, the second fluid flow direction is as follows: Figure 1 As indicated by the solid arrow in the middle.

[0134] like Figure 1 and Figure 2 As shown, high-temperature synthesis gas N1 at 5.0 MPaG@650℃ is introduced from the first fluid inlet 201, enters the pressure shell section 2111 within the shell-side cylinder 211, then enters the interior of the shell-side internals 27, passes through the liner reducer section 272, enters the interior of the liner 271, and the exterior of the heat exchange tube 224. After heat exchange through the second baffle 210, low-temperature synthesis gas N2, with its temperature reduced to 400℃, flows out of the liner 271, then flows through the gap between the liner 271 and the tube sheet 24 to the annular flow channel 23, and is transported to the manifold 262 through the liner connecting pipe 261. Inside the manifold 262, it mixes with a portion of the unheated 5.0 MPaG@650℃ high-temperature synthesis gas N1 that enters through the connecting pipe 263 via valve 264, and finally exits the shell 21 through the first fluid outlet 202, where the fluid temperature approaches that of the low-temperature synthesis gas N2. Figure 6 and Figure 12 As shown.

[0135] With this design, except for the first fluid inlet 201 and the pressure-bearing shell section 2111 of the shell-side cylinder 211, the synthesis gas in contact with the ordinary section of the shell-side cylinder 211 is low-temperature synthesis gas N2 (≈400℃) after heat exchange and cooling. Therefore, a heat insulation layer 2112 is installed on the inner wall of the pressure-bearing shell section 2111 of the shell-side cylinder 211. The design temperature of the shell 21 of the ordinary section of the shell-side cylinder 211 can be taken as 415℃ (with a 15℃ margin), and conventional chromium molybdenum steel can be selected as the material. The design temperature of the shell 21 of the pressure-bearing shell section 2111 protected by the heat insulation layer 2112 is even lower than 400℃. Since the inner and outer sides of the liner 271 are the same medium with the same pressure, it only bears the temperature of the high-temperature synthesis gas N1 and does not bear pressure load. Therefore, conventional stainless steel can be selected.

[0136] like Figure 1 and Figure 2 As shown, low-temperature saturated steam N3 at 11.0 MPaG@318℃ is fed into the tube box shell 212 through the second fluid inlet 203, flows through the tube sheet 24 and through the interior of the heat exchange tube assembly 22, and after exchanging heat with the high-temperature synthesis gas, high-temperature superheated steam N4 with a temperature increased to 525℃ is formed at the tail of the heat exchange tube assembly 22. This example uses four sets of heat exchange tube assemblies 22; for specific configuration, refer to [reference needed]. Figures 7-10 ,in Figure 7 , Figure 8 View from direction C, Figure 9 , Figure 10 This is a view from direction D. Each heat exchanger tube assembly 22 consists of multiple sets of small, thin heat exchanger tubes 224 and a gas guide tube 221. The tail ends of the multiple sets of heat exchanger tubes 224 are equipped with small ring tube plates 223 and semi-ring tubes 222 to collect superheated steam. The multiple sets of heat exchanger tubes 224 are mounted on a set of small ring tube plates 223, which are connected to a set of semi-ring tubes 222. Each set of semi-ring tubes 222 transports high-temperature superheated steam N4 to the collecting tube assembly 28 through four gas guide tubes 221. The collecting tube assembly 28 then delivers the 11.0 MPaG@525℃ high-temperature superheated steam N4 out of the shell 21. Figure 1 and Figure 11 As shown, a gap is provided between the main collection pipe 283 and the tube sheet 24, and the gap is filled with ceramic fiber products, preferably ceramic fiber rope as the filling layer 9, to prevent the heat of the high-temperature superheated steam N4 from being directly transferred to the tube sheet 24. The main collection pipe 283 is connected to the tube sheet 24 through a first expansion joint 284, and a second expansion joint 285 is also provided on the main collection pipe 283 to ensure that the main collection pipe 283 absorbs its own expansion in the axial direction.

[0137] Through the above design, the tube sheet 24, on the syngas side, contacts low-temperature syngas N2 at approximately 400°C after heat exchange, and on the steam side, contacts low-temperature saturated steam N3 at approximately 318°C. Therefore, the design temperature of the tube sheet 24 can be taken as 415°C (with a 15°C margin), and conventional chromium-molybdenum steel can be selected as the material. The shell-side cylinder 211 contacts the medium of low-temperature syngas N2 at 400°C after heat exchange, and the design temperature can be taken as 415°C (with a 15°C margin). Conventional chromium-molybdenum steel can be selected as the material. The inner wall of the pressure shell section 2111 of the shell-side cylinder 211 is separately equipped with refractory material as a heat insulation layer 2112. The medium contacted by the tube box cylinder 212 and the tube box end cap 25 is low-temperature saturated steam N3 at 318°C, and conventional carbon steel can be selected as the material. The media contacted on both sides of the small ring tube sheet 223, semi-ring tube 222, and gas guide tube 221 are high-temperature and high-pressure synthesis gas and superheated steam. However, the diameters of the small ring tube sheet 223 and semi-ring tube 222 are very small, approximately 150 mm, which can be met by conventional stainless steel or nickel-based stainless steel. Meanwhile, the diameter of the main collecting pipe 283 is generally ≤ DN300 mm (DN refers to the nominal diameter of the pipe), which can also be met by conventional stainless steel or nickel-based stainless steel.

[0138] like Figure 1 As shown, when the temperature reading of the thermometer T on the high-temperature pipeline at the second fluid outlet 204 is found to be mismatched with the preset threshold due to equipment load adjustment or fluctuation, the valve 264 can be adjusted by the actuator 266 to change the flow rate of the high-temperature synthesis gas N1 entering the connecting pipe 263 from the pressure-bearing housing 2111. At this time, the flow rate of the high-temperature synthesis gas N1 through the connecting pipe 263 will increase or decrease accordingly, that is, the amount of high-temperature synthesis gas entering the outer liner 271 of the heat exchange tube 224 will decrease or increase accordingly. At this time, the temperature of the superheated steam will decrease or increase accordingly, so that the saturated steam at the second fluid outlet 204 reaches the preset conditions.

[0139] As described above, the tube sheet 24, shell-side cylinder 211, tube box cylinder 212, and tube box end cap 25 are all located in a non-high-temperature environment, allowing for the selection of suitable materials. Simultaneously, the tube sheet 24 as a whole is in a non-high-temperature environment, effectively reducing thermal stress, preventing leaks at pipe joints, and ensuring safe, long-term, and stable operation of the equipment. Furthermore, the tube-side outlet temperature of this shell-and-tube heat exchanger 2 can be adjusted using internal regulating components, increasing the equipment's safety and application options.

[0140] It should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0141] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A shell-and-tube heat exchanger, characterized by The shell (21) and the tube plate (24) arranged inside the shell (21), the tube plate (24) divides the shell (21) into the shell side cylinder (211) and the tube side cylinder (212), the first fluid inlet (201) is arranged on the side of the shell side cylinder (211) away from the tube plate (24); The shell side cylinder (211) is provided with a shell side inner part (27) with a gap along the wall, the shell side inner part (27) is a cavity with both ends open, the end of the shell side inner part (27) close to the tube plate (24) is suspended, and the other end extends to the inner wall of the shell side cylinder (211) in the radial direction and is sealingly connected with the inner wall of the shell side cylinder (211) to form an annular gap flow channel (23); The part of the shell side cylinder (211) away from the shell side inner part (27) is a pressure-bearing shell (2111) subjected to heat insulation treatment, an adjusting assembly (26) is arranged in the pressure-bearing shell (2111), the adjusting assembly (26) is in communication with the pressure-bearing shell (2111) through an adjusting component to control the flow rate of the fluid, the adjusting assembly (26) is also in communication with the annular gap flow channel (23), and the outlet of the adjusting assembly (26) extends out of the shell side cylinder (211) to form a first fluid outlet (202); The tube side cylinder (212) is provided with a second fluid inlet (203), the tube plate (6) is provided with a heat exchange pipe assembly (22) and a collecting pipe assembly (28) and both extend into the shell side inner part (27), the collecting pipe assembly (28) is in communication with the heat exchange pipe assembly (22) on one side of the shell side inner part (27) and extends out of the shell (21) on the other side to form a second fluid outlet, and the heat exchange pipe assembly (22) is in communication with the tube side cylinder (212) on the side close to the tube side cylinder (212).

2. The shell and tube heat exchange apparatus according to claim 1, wherein, The adjusting assembly (26) includes two groups of inlets and one group of outlets, a plurality of lining tube connecting pipes (261) can be arranged, the lining tube connecting pipes (261) converge to a collecting pipe (262) to form a first group of inlets, the internal space of the pressure-bearing shell (2111) is in communication with the collecting pipe (262) to form a second group of inlets, and the collecting pipe (262) is in communication with the outside of the shell (21) to form a group of outlets; wherein the flow rate of the fluid flowing in through the second group of inlets can be adjusted.

3. The shell and tube heat exchange apparatus of claim 2, wherein, The collecting pipe (262) is an annular pipe, a connecting pipe (263) is in communication with the collecting pipe (262) to form the second group of inlets, the adjusting component includes a valve (264), a valve rod (265) and an actuator (266), the valve (264) is arranged at the inlet of the connecting pipe (263), the valve rod (265) connected with the valve (264) extends out of the shell (21) and is connected with the actuator (266).

4. The shell and tube heat exchange apparatus according to claim 3, wherein One end of the lining tube connecting pipe (261) is in communication with the annular gap flow channel (23), and the other end is in communication with the collecting pipe (262).

5. The shell and tube heat exchange apparatus of claim 1, wherein, The shell side inner part (27) comprises a liner (271) and a liner variable diameter section (272), the liner (271) is kept apart from the shell side cylinder (211), one end of the liner variable diameter section (272) is connected with the liner (271), and the other end extends to the shell side cylinder (211) in the radial direction, and the liner (271) is kept apart from the tube sheet (24) on one side close to the tube sheet (24) to make the first fluid flow through the gap to the annular gap flow channel (23).

6. The shell and tube heat exchange apparatus of claim 1, wherein, The heat exchange tube assembly (22) comprises heat exchange tubes (224) and gas guide tubes (221) connected with the heat exchange tubes (224), and a plurality of groups of the gas guide tubes (221) are connected with the collection tube assembly (28).

7. The shell and tube heat exchange apparatus of claim 6, wherein, The heat exchange tubes (224) are uniformly distributed in a ring shape.

8. The shell and tube heat exchange apparatus of claim 6, wherein, The heat exchange tubes (224) are uniformly distributed in a point shape.

9. The shell and tube heat exchange apparatus of claim 6, wherein, The heat exchange tubes (224) are combinedly distributed in a ring shape and a point shape.

10. The shell and tube heat exchange apparatus of claim 6, wherein, The end of the gas guide tube (221) close to the heat exchange tube (224) is provided with a half ring tube (222), the half ring tube (222) is provided with a small ring tube sheet (223), and the small ring tube sheet (223) is connected with the heat exchange tube (224).

11. The shell and tube heat exchange apparatus of claim 6, wherein, The collection tube assembly (28) comprises a collection tube main pipe (283) and a second fluid collection inlet (282) arranged on one side of the collection tube main pipe (283), and the second fluid collection inlet (282) is connected with the gas guide tube (221).

12. The shell and tube heat exchange apparatus of claim 11, wherein, A filling layer (29) is arranged between the collection tube main pipe (283) and the tube sheet (24).

13. The shell and tube heat exchange apparatus of claim 12, wherein, The connection between the collection tube main pipe (283) and the tube sheet (24) in the tube box cylinder (212) is provided with a first expansion joint (284) arranged outside the collection tube main pipe (283), one side of the first expansion joint (284) is fixedly connected with the tube sheet (24), and the other side is fixedly connected with the outer wall of the collection tube main pipe (283).

14. The shell and tube heat exchange apparatus of claim 13, wherein, The end of the tube box cylinder (212) away from the tube sheet (24) is provided with a tube box head (25), the collection tube main pipe (283) extends out of the shell (21) through the tube box head (25), and a section of the collection tube main pipe (283) in the tube box head (25) is provided with a second expansion joint (55).

15. A method of using a shell and tube heat exchange apparatus, characterized in that, The shell and tube heat exchange equipment (2) of any one of claims 1-14 is used, the flow process of the first fluid is shell side, and the flow process of the second fluid is tube side, and the specific operation steps are as follows: S01, when the equipment needs to be started, steam is input into the tube side to preheat the equipment; S02, the second fluid medium is input into the tube side, and the medium is stably conveyed; S03, the first fluid medium is slowly input into the shell side; S04, when the outlet temperature of the tube side medium does not reach a predetermined value, the adjusting part of the shell side is adjusted to control the flow of the first fluid, until the outlet temperature of the tube side medium reaches the predetermined value; S04, when the equipment needs to be stopped, the medium is slowly stopped from being conveyed to the shell side until the medium is completely stopped from being conveyed to the shell side; S05, the medium is slowly stopped from being conveyed to the tube side until the medium is completely stopped from being conveyed to the tube side.

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