A self-cleaning shell and tube heat exchanger

Abstract

The present invention relates to the technical field of heat exchange equipment, and specifically to a self-cleaning shell and tube heat exchanger, which aims to solve the problem of reduced heat transfer efficiency in traditional heat exchangers due to dirt deposition. The heat exchanger includes a shell, a spiral tube group and a self-cleaning device. A spiral spoiler is provided inside the spiral tube group. The spoiler is elastic and maintains a consistent angle with the spiral tube group during normal operation, thereby enhancing the turbulence of the fluid and improving the heat transfer efficiency. When it is detected that dirt accumulation affects the heat exchange efficiency, the power device adjusts the spoiler angle to generate stronger shear force and local turbulence, thereby achieving online cleaning. The present invention not only effectively prevents dirt deposition, but also greatly reduces the need for downtime maintenance, improves heat exchange efficiency, and improves the continuity and stability of equipment operation.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange equipment, and in particular to a self-cleaning shell and tube heat exchanger. Background Art

[0002] The information disclosed in the background of the invention is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Shell-and-tube heat exchangers, core equipment in the industrial heat transfer field, have long faced the problem of heat transfer efficiency degradation caused by fouling in their static structure consisting of the shell and tube bundle. In traditional designs, the fixed tubesheet layout easily leads to fouling accumulation between the tubes, creating a vicious cycle of fouling, increased thermal resistance, and reduced flow rate. Experimental studies have shown that when the fouling thermal resistance increases by 30%, the heat transfer efficiency decreases by 15-20%.

[0004] To solve the above problems, existing technologies use split shells to achieve manual cleaning of the tube bundle, but this requires downtime and disassembly (taking more than 8 hours per operation), and frequent disassembly increases the risk of seal failure. Therefore, existing technologies use the following technical means to solve the problem:

[0005] First, online physical cleaning is adopted: such as built-in rotating brush or rubber ball circulation system. Although it can partially realize online operation, it has problems such as severe mechanical wear (brush life is less than 6 months), greatly increased flow resistance (pressure loss increases by about 30%) and blind spots in shell-side cleaning.

[0006] Second, chemical cleaning technology is used: acid / alkaline solution circulation is used to dissolve dirt, but the corrosiveness of the chemicals causes the annual pipe wall loss to be greater than 0.1mm, and the waste liquid treatment cost accounts for more than 40% of the total maintenance cost, making the maintenance cost too high.

[0007] Third, adopt passive anti-fouling design: such as surface coating or optimizing tube bundle arrangement. This method can only slow down the fouling rate but cannot eliminate the deposition problem.

[0008] In summary, traditional solutions are no longer able to meet the demands of continuous production due to the high frequency of downtime for cleaning and the surge in maintenance costs. Therefore, there is an urgent need for a dynamic self-cleaning shell-and-tube heat exchanger that can remove dirt online without disassembly, thereby continuously optimizing heat transfer efficiency. Summary of the Invention

[0009] In view of the problems existing in the prior art, the purpose of the present invention is to provide a self-cleaning shell and tube heat exchanger, aiming to solve the problem of reduced heat transfer efficiency due to dirt deposition in traditional heat exchangers.

[0010] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0011] A self-cleaning shell and tube heat exchanger comprises a shell, the shell comprising an upper shell and a lower shell, the lower shell being provided with a plurality of guide plates constituting a heat exchange flow channel, a heat exchange tube assembly being installed in the heat exchange flow channel, a water inlet and a water outlet being provided at both ends of the heat exchange flow channel, and the heat exchange tube assembly being provided with a liquid inlet and a liquid outlet; and characterized in that:

[0012] The heat exchange tube assembly includes a spiral tube group and a self-cleaning device;

[0013] The spiral tube group includes one or more spiral heat exchange tubes with inner and outer layers, and the two ends of the spiral heat exchange tubes are respectively connected to the liquid inlet and the liquid outlet;

[0014] The self-cleaning device includes a spiral spoiler arranged on the inner side of the innermost spiral heat exchange tube and along the spiral center line thereof;

[0015] The spiral spoiler is elastic and has the same spiral angle as the spiral tube group in the initial state, and is used to cooperate with the spiral tube group to form a spiral flow state for the liquid in the heat exchange flow channel;

[0016] The spiral spoiler is sleeved on the central guide rod, and the central guide rod is installed and fixed in the heat exchange flow channel;

[0017] The power device includes a pull rod, and the spiral spoiler is connected to the cross slide plate by the pull rod on both sides near the middle. The cross slide plate is slidably installed along the heat exchange flow channel. Under the action of the power assembly, the corresponding spiral spoiler is driven by the corresponding pull rod to slide toward the middle along the central guide rod, so that the spiral angle of the corresponding spiral spoiler near the middle position increases, and the spiral angle near the turning point formed by the spiral spoiler at the turning point of the heat exchange flow channel increases.

[0018] After the self-cleaning mode is turned on, the spiral spoiler is deformed under the action of the power device, so that it forms an angle with the spiral tube group, generating stronger shear force and local turbulence, thereby achieving online cleaning.

[0019] Preferably, the spiral heat exchange tubes include a heat exchange tube body and a spiral heat conduction wing plate arranged on the outer wall of the heat exchange tube body along its spiral line. The spiral heat conduction wing plate is used for heat conduction and is also used to assist the spiral tube group to make the liquid in the heat exchange channel form a spiral flow state.

[0020] Preferably, the spiral spoiler has a built-in shape memory alloy wire, which is connected to a temperature control circuit to achieve dynamic adjustment of the spiral angle.

[0021] Preferably, the surface of the spiral spoiler is integrated with a piezoelectric ceramic sheet, which removes dirt through high-frequency vibration and fluid flushing.

[0022] Preferably, the power assembly includes a transmission rod whose lower end is clamped or riveted to the corresponding transverse slide, the transmission rod is mounted on the lead screw body through the corresponding lead screw nut, and the lead screw body is mounted on the mounting seat of the upper shell;

[0023] The screw lever body is driven by a driven wheel installed on the screw lever body to rotate through a driving wheel installed on the output end of the driving motor.

[0024] Preferably, the upper shell is provided with a mounting box for the power assembly.

[0025] Preferably, the central guide rod is tubular and communicates with the liquid inlet and the liquid outlet;

[0026] The spiral spoiler is mounted on the central guide rod via a sliding sleeve, and the spiral spoiler and the corresponding sliding sleeve are connected and fixed via three or more supporting rods.

[0027] The present invention has at least the following beneficial effects:

[0028] Improve heat transfer efficiency: The present invention introduces spiral spoilers, spiral heat exchange tubes and spiral heat conduction wing plates to form a spiral flow pattern in the heat exchange channel. This design enhances the turbulence of the fluid and improves the heat transfer coefficient.

[0029] Dynamic Self-Cleaning: This system utilizes a self-cleaning mechanism that uses a power unit to adjust the angle of the spiral spoiler to alter the fluid flow pattern, generating stronger shear forces and localized turbulence, effectively stripping away dirt particles adhering to the pipe walls. This significantly reduces the need for downtime and disassembly required by traditional cleaning methods, improving the continuity and stability of equipment operation.

[0030] Reduced maintenance costs: Compared with traditional physical or chemical cleaning methods, this self-cleaning design reduces the risk of seal failure caused by frequent disassembly and reinstallation, while avoiding the corrosion problems caused by the use of acid / alkali solution circulation to dissolve dirt and the high waste liquid disposal costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 Schematic diagram of the structure of the spiral heat exchange tube;

[0033] Figure 3 Schematic diagram of the installation structure of the spiral spoiler;

[0034] Figure 4 Schematic diagram of the coordinated installation structure of the spiral heat exchange tube and the spiral spoiler.

[0035] The reference numerals are as follows:

[0036] 100, lower shell; 110, water inlet; 120, water outlet; 130, liquid inlet; 140, liquid outlet; 200, spiral heat exchange tube; 210, heat exchange tube body; 220, spiral heat conduction wing plate; 300, spiral spoiler; 310, sliding sleeve; 320, support rod; 400, center guide rod; 500, upper shell; 501, installation box; 600, power assembly; 610, cross slide; 620, transmission rod; 630, lead screw body; 640, mounting seat; 650, lead screw sleeve; 660, driven wheel; 670, drive motor; 680, driving wheel; 690, pull rod. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0038] Figures 1 to 4 A self-cleaning shell-and-tube heat exchanger is shown, comprising a housing, the housing comprising an upper housing 500 and a lower housing 100. A plurality of guide plates forming a heat exchange channel are disposed within the lower housing 100. A heat exchange tube assembly is installed within the heat exchange channel. A water inlet 110 and a water outlet 120 are disposed at both ends of the heat exchange channel. The heat exchange tube assembly is provided with a liquid inlet 130 and a liquid outlet 140. The invention is characterized in that:

[0039] The heat exchange tube assembly includes a spiral tube group and a self-cleaning device;

[0040] The spiral tube group includes one or more spiral heat exchange tubes 200 (one is used as an example in this embodiment) with inner and outer layers. The two ends of the spiral heat exchange tube 200 are respectively connected to the liquid inlet 130 and the liquid outlet 140;

[0041] The self-cleaning device includes a spiral spoiler 300 arranged on the inner side of the innermost spiral heat exchange tube 200 and arranged along the spiral center line thereof;

[0042] The spiral spoiler 300 is elastic and has the same spiral angle as the spiral tube group in the initial state, and is used to cooperate with the spiral tube group to form a spiral flow state of the liquid in the heat exchange flow channel;

[0043] After the self-cleaning mode is turned on, the spiral spoiler 300 is deformed under the action of the power device, so that it forms an angle with the spiral tube group, generating stronger shear force and local turbulence, thereby achieving online cleaning.

[0044] This design optimizes the fluid flow pattern by changing the relative angle between the spoiler and the spiral heat exchange tube 200, thereby preventing dirt deposition.

[0045] Normal Operation: When the equipment is operating normally, the spiral baffles 300 maintain a consistent angle with the spiral heat exchange tubes 200, ensuring smooth fluid flow along the spiral path while maximizing heat transfer efficiency. The baffles not only enhance fluid turbulence and improve heat transfer coefficients, but also reduce direct impact of the fluid on the tube walls, slowing wear and corrosion.

[0046] Self-cleaning mode: Once the system detects that dirt accumulation is affecting heat exchange efficiency, it initiates a self-cleaning process. A power device (such as a motor or hydraulic device) adjusts the angle of the spiral baffle 300 to create a specific angle relative to the spiral heat exchange tube 200. This change significantly alters the fluid flow pattern, generating stronger shear forces and localized turbulence. These forces effectively remove dirt particles adhering to the tube walls, achieving online cleaning and reducing their adverse effects on heat exchange.

[0047] In order to improve the heat exchange efficiency, the spiral heat exchange tube 200 includes a heat exchange tube body 210 and a spiral heat conduction wing plate 220 arranged on the outer wall of the heat exchange tube body 210 along its spiral line. The spiral heat conduction wing plate 220 is used for heat conduction and is also used to assist the spiral tube group to form a spiral flow state of the liquid in the heat exchange channel.

[0048] The spiral spoiler 300 is installed as follows: it is sleeved on the central guide rod 400, and the central guide rod 400 is installed and fixed in the heat exchange flow channel.

[0049] The structure of the power device may be as follows: it includes a pull rod, and the spiral spoiler 300 is connected to the transverse slide 610 on both sides near the middle through the pull rod. The transverse slide 610 is slidably installed along the heat exchange flow channel. Under the action of the power component 600, the corresponding spiral spoiler 300 is driven by the corresponding pull rod to slide toward the middle along the central guide rod 400, so that the spiral angle of the corresponding spiral spoiler 300 near the middle position is reduced, and the spiral angle near the turning point formed by the spiral spoiler 300 at the turning point of the heat exchange flow channel is increased.

[0050] The helix angle is reduced in the middle part of the flow channel to enhance the self-cleaning effect, and the helix angle is increased at the turning point to reduce the resistance to the fluid and prevent dirt deposition:

[0051] In the middle of the flow channel, fluid flow is relatively smooth, and dirt is easily deposited in this area. By reducing the angle of the spiral spoiler 300, the local turbulence intensity and shear force can be significantly enhanced. These turbulence and shear forces help to peel off and remove dirt particles deposited on the tube wall, effectively improving the self-cleaning ability and thus the heat exchange efficiency.

[0052] Dynamic Adjustment Mechanism: When self-cleaning is required, a power device (such as a motor or hydraulic device) adjusts the angle of the spiral spoiler 300 to form a larger angle with the spiral heat exchange tube 200. This dynamic adjustment not only provides a powerful cleaning effect when needed, but also allows for flexible control based on actual operating conditions, avoiding unnecessary energy consumption.

[0053] The structure of the power assembly 600 is as follows: it includes a transmission rod 620 whose lower end is clamped or riveted to the corresponding cross slide 610. The transmission rod 620 is mounted on a lead screw body 630 through a corresponding lead screw nut. The lead screw body 630 is mounted on a mounting seat 640 of the upper housing 500.

[0054] The screw lever body 630 is driven by a driven wheel 660 mounted on the screw lever body 630 to rotate via a driving wheel 680 mounted on the output end of a driving motor 670 .

[0055] To facilitate maintenance and installation, the upper housing 500 is provided with an installation box 501 for the power assembly 600 .

[0056] In addition to the above methods, the simplest way to drive the horizontal slide plate 610 to slide is to drive it through a telescopic device. However, the telescopic device (such as a linear motor) will have a greater blocking effect on the fluid, thereby increasing the fluid resistance and pressure, affecting the cleaning effect. Although cleaning can be achieved, the cleaning effect is not optimal. In order to solve the above problem, the single spiral spoiler 300 is divided into multiple sections (3-5 sections), each section is independently connected to a micro linear motor (to reduce liquid resistance), and the compression amount of each section is synchronously adjusted by the controller to ensure that the spiral angle changes evenly. This method optimizes the fluid resistance and pressure loss, and has a better cleaning effect than the former, thereby ensuring heat exchange efficiency.

[0057] To further enhance performance, the spiral spoiler 300 incorporates a shape memory alloy wire, which is connected to a temperature control circuit (using existing technology) to dynamically adjust the spiral angle. A piezoelectric ceramic sheet is integrated onto the surface of the spoiler, which uses high-frequency vibrations to coordinate with fluid flushing to remove dirt. The above design significantly enhances the intelligence and cleaning efficiency of the device. The memory alloy can be a nickel-titanium alloy, which can not only withstand the various chemicals that may be present inside the heat exchanger, but also ensure stability and reliability under long-term operation. Furthermore, the high fatigue life of nickel-titanium alloy means it can withstand multiple shape changes without damage, which is particularly important for devices that frequently perform self-cleaning operations.

[0058] The central guide rod 400 is tubular and communicates with the liquid inlet 130 and the liquid outlet 140 . This design allows the central guide rod 400 to not only play a guiding and supporting role but also be used to improve heat exchange efficiency.

[0059] The spiral spoiler 300 is mounted on the central guide rod 400 via a sleeve 310 . The spiral spoiler 300 and the corresponding sleeve 310 are connected and fixed via three or more support rods 320 , thereby maximizing the fluid passage area and reducing resistance to the liquid, thereby improving heat exchange efficiency.

[0060] In order to reduce the resistance of the fluid passing through, the cross section of the spiral spoiler is streamlined, and the inlet end of the heat exchange channel as a whole and along the corresponding flow section are arranged to be higher than the outlet end.

[0061] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0062] The terms "upper," "lower," "outer," "inner," and the like, if used in the present description and claims, and in the accompanying drawings, are used to distinguish relative positions and are not necessarily qualitative. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions.

[0063] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-cleaning shell and tube heat exchanger, comprising a housing, the housing comprising an upper housing and a lower housing, the lower housing being provided with a plurality of guide plates forming a heat exchange flow channel, a heat exchange tube assembly being installed in the heat exchange flow channel, a water inlet and a water outlet being provided at both ends of the heat exchange flow channel, and the heat exchange tube assembly being provided with a liquid inlet and a liquid outlet; characterized in that: The heat exchange tube assembly includes a spiral tube group and a self-cleaning device; The spiral tube group includes one or more spiral heat exchange tubes with inner and outer layers, and the two ends of the spiral heat exchange tubes are respectively connected to the liquid inlet and the liquid outlet; The self-cleaning device includes a spiral spoiler arranged on the inner side of the innermost spiral heat exchange tube and along the spiral center line thereof; The spiral spoiler is elastic and has the same spiral angle as the spiral tube group in the initial state, and is used to cooperate with the spiral tube group to form a spiral flow state for the liquid in the heat exchange flow channel; The spiral spoiler is sleeved on the central guide rod, and the central guide rod is installed and fixed in the heat exchange flow channel; The power device includes a pull rod, and the spiral spoiler is connected to the cross slide plate by the pull rod on both sides near the middle. The cross slide plate is slidably installed along the heat exchange flow channel. Under the action of the power component, the corresponding spiral spoiler is driven by the corresponding pull rod to slide toward the middle along the central guide rod, so that the spiral angle of the corresponding spiral spoiler near the middle position decreases, and the spiral angle near the turning point formed by the spiral spoiler at the turning point of the heat exchange flow channel increases. After the self-cleaning mode is turned on, the spiral spoiler is deformed under the action of the power device, so that it forms an angle with the spiral tube group, generating stronger shear force and local turbulence, thereby achieving online cleaning.

2. The self-cleaning shell and tube heat exchanger according to claim 1, characterized in that: The spiral heat exchange tubes each include a heat exchange tube body and a spiral heat conduction wing plate arranged on the outer wall of the heat exchange tube body along its spiral line. The spiral heat conduction wing plate is used for heat conduction and is also used to assist the spiral tube group to form a spiral flow state of the liquid in the heat exchange flow channel.

3. The self-cleaning shell and tube heat exchanger according to claim 1, wherein: The spiral spoiler has a built-in shape memory alloy wire, which is connected to a temperature control circuit to achieve dynamic adjustment of the spiral angle.

4. The self-cleaning shell and tube heat exchanger according to claim 3, characterized in that: The surface of the spiral spoiler is integrated with a piezoelectric ceramic sheet, which removes dirt through high-frequency vibration and fluid flushing.

5. The self-cleaning shell and tube heat exchanger according to claim 1, wherein: The power assembly includes a transmission rod with a lower end engaged or riveted with a corresponding transverse slide, the transmission rod is mounted on a lead screw body through a corresponding lead screw nut, and the lead screw body is mounted on a mounting seat of the upper housing; The screw lever body is driven by a driven wheel installed on the screw lever body to rotate through a driving wheel installed on the output end of the driving motor.

6. The self-cleaning shell and tube heat exchanger according to claim 5, characterized in that: The upper shell is provided with a mounting box for the power assembly.

7. The self-cleaning shell and tube heat exchanger according to any one of claims 1 to 6, characterized in that: The central guide rod is tubular and connected to the liquid inlet and the liquid outlet; The spiral spoiler is mounted on the central guide rod via a sliding sleeve, and the spiral spoiler and the corresponding sliding sleeve are connected and fixed via three or more supporting rods.

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