Self-cleaning shell-and-tube heat exchanger

Abstract

The invention relates to the technical field of heat exchange equipment, in particular to a self-cleaning shell-and-tube heat exchanger, and aims to solve the problem that the heat transfer efficiency of a traditional heat exchanger is reduced due to dirt deposition. The heat exchanger comprises a shell, a spiral pipe set and a self-cleaning device. A spiral spoiler is arranged in the spiral pipe set, the spoiler has elasticity, the spoiler and the spiral pipe set are kept at the same angle during normal work, the fluid turbulence degree is enhanced, and the heat transfer efficiency is improved. When it is detected that dirt accumulation influences the heat exchange efficiency, the power device adjusts the angle of the spoiler, stronger shearing force and local turbulence are generated, and online cleaning is achieved. Dirt deposition is effectively prevented, the shutdown maintenance requirement is greatly reduced, the heat exchange efficiency is improved, and the continuity and stability of equipment operation are improved.

Description

Technical Field

[0001] The 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 the understanding of the overall background of the invention and should not be necessarily regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] As the core equipment in the field of industrial heat transfer, the shell and tube heat exchanger has long faced the problem of heat transfer efficiency attenuation caused by dirt deposition in its static structure composed of shell and tube bundle. In traditional designs, the fixed tube sheet layout easily leads to dirt accumulation between tubes, forming a vicious cycle of "fouling-increased thermal resistance-reduced flow rate". Experiments show that when the dirt thermal resistance increases by 30%, the heat transfer efficiency decreases by 15-20%.

[0004] To solve the above problems, the existing technology uses a split shell to achieve manual cleaning of the tube bundle, but it needs to be shut down for disassembly (taking more than 8 hours for each time), and frequent disassembly leads to an increased risk of seal failure. Therefore, the existing technology uses 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 partially realizes online operation, there are 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 cleaning.

[0006] Second, chemical cleaning technology is used: the dirt is dissolved through acid / alkaline solution circulation, but the corrosiveness of the chemicals causes the annual loss of the pipe wall to be greater than 0.1mm, and the cost of waste liquid treatment 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, the traditional solution can no longer meet the needs of continuous production due to the high frequency of shutdown 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, comprising a shell, the shell comprising an upper shell and a lower shell, a plurality of guide plates constituting a heat exchange flow channel are arranged in the lower shell, a heat exchange tube assembly is installed in the heat exchange flow channel, a water inlet and a water outlet are arranged at both ends of the heat exchange flow channel, and the heat exchange tube assembly is provided with a liquid inlet and a liquid outlet; 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 comprises a spiral spoiler arranged on the inner side of the innermost spiral heat exchange tube and arranged 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 make the liquid in the heat exchange flow channel form a spiral flow state;

[0016] 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.

[0017] 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.

[0018] Preferably, the spiral spoiler is sleeved on a central guide rod, and the central guide rod is installed and fixed in the heat exchange flow channel.

[0019] 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.

[0020] Preferably, a piezoelectric ceramic sheet is integrated on the surface of the spoiler to remove dirt through high-frequency vibration and fluid flushing.

[0021] Preferably, the power device includes a pull rod, and the spiral spoiler is connected to the cross slide on both sides near the middle through the pull rod. The cross slide 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 center 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 decreases.

[0022] Preferably, the power assembly comprises a transmission rod whose lower end is clamped or riveted to the corresponding transverse sliding plate, 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 drives 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 connected to the liquid inlet and the liquid outlet;

[0026] The spiral spoiler is installed on the central guide rod through a sliding sleeve, and the spiral spoiler and the corresponding sliding sleeve are connected and fixed by more than three supporting rods.

[0027] Preferably, the cross section of the spoiler is streamlined;

[0028] The heat exchange flow channel as a whole and along the corresponding flow section are arranged with the inlet end higher than the outlet end.

[0029] The present invention has at least the following beneficial effects:

[0030] Improve heat transfer efficiency: The present invention introduces a spiral spoiler, a spiral heat exchange tube and a spiral heat conduction wing plate to form a spiral flow pattern in the heat exchange flow channel. This design enhances the turbulence of the fluid and improves the heat transfer coefficient.

[0031] Dynamic self-cleaning function: The present invention adopts a self-cleaning mechanism, which changes the fluid flow pattern by adjusting the angle of the spiral spoiler through a power device, generating stronger shear force and local turbulence, thereby effectively stripping off the dirt particles attached to the pipe wall. This greatly reduces the need for shutdown and disassembly in traditional cleaning methods, and improves the continuity and stability of equipment operation.

[0032] 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 liquid cycles to dissolve dirt and the high cost of waste liquid disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the spiral heat exchange tube;

[0035] Figure 3 Schematic diagram of the installation structure of the spiral spoiler;

[0036] Figure 4 It is a schematic diagram of the coordinated installation structure of the spiral heat exchange tube and the spiral spoiler.

[0037] The reference numerals are as follows:

[0038] 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, horizontal slide plate; 620, connecting 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

[0039] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0040] Figures 1 to 4 A self-cleaning shell and tube heat exchanger is shown, comprising a shell, the shell comprising an upper shell 500 and a lower shell 100, a plurality of guide plates constituting a heat exchange flow channel are arranged in the lower shell 100, a heat exchange tube assembly is installed in the heat exchange flow channel, a water inlet 110 and a water outlet 120 are arranged at both ends of the heat exchange flow channel, and the heat exchange tube assembly is provided with a liquid inlet 130 and a liquid outlet 140; the characteristics are:

[0041] The heat exchange tube assembly includes a spiral tube group and a self-cleaning device;

[0042] 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, and both ends of the spiral heat exchange tube 200 are connected to the liquid inlet 130 and the liquid outlet 140 respectively;

[0043] The self-cleaning device includes a spiral spoiler 300 arranged inside the innermost spiral heat exchange tube 200 and arranged along the spiral center line thereof;

[0044] 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 make the liquid in the heat exchange flow channel form a spiral flow state;

[0045] 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.

[0046] This design optimizes the fluid flow pattern by changing the relative angle between the spoiler and the spiral heat exchange tube 200, thereby achieving the purpose of preventing dirt deposition.

[0047] Normal working state: When the equipment is in normal operating conditions, the spiral spoiler 300 maintains a consistent angle with the spiral heat exchange tube 200, which ensures that the fluid flows smoothly along the spiral path while maximizing the heat exchange efficiency. At this time, the spoiler not only helps to enhance the turbulence of the fluid and improve the heat transfer coefficient, but also reduces the direct impact of the fluid on the tube wall, slowing down wear and corrosion.

[0048] Self-cleaning mode: Once it is detected that dirt accumulation affects the heat exchange efficiency, the system will start the self-cleaning program. The angle of the spiral spoiler 300 is adjusted by a power device (such as a motor or a hydraulic device) to form a certain angle with the spiral heat exchange tube 200. This change causes a significant change in the fluid flow pattern, generating stronger shear force and local turbulence, which can effectively peel off the dirt particles attached to the tube wall, achieve online cleaning, and reduce its adverse effects on heat exchange.

[0049] 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 conductive wing plate 220 arranged on the outer wall of the heat exchange tube body 210 along its spiral line. The spiral heat conductive wing plate 220 is used for heat conduction and is also used to assist the spiral tube group to form a spiral flow state for the liquid in the heat exchange channel.

[0050] 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.

[0051] 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 plate 610 on both sides near the middle through the pull rod. The transverse slide plate 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 increases, and the spiral angle near the turning point decreases.

[0052] Increase the helix angle in the middle of the flow channel to enhance the self-cleaning force, and reduce the helix angle at the turning point to reduce the resistance to the fluid and prevent dirt deposition:

[0053] In the middle part of the flow channel, the fluid flows relatively smoothly and dirt is easily deposited in this area. By increasing the angle of the spiral spoiler 300, the local turbulence intensity and shear force can be significantly enhanced. These turbulence and shear force help to peel off and carry away the dirt particles deposited on the tube wall, thereby effectively improving the self-cleaning ability and thus improving the heat exchange efficiency.

[0054] Dynamic adjustment mechanism: When self-cleaning is required, the angle of the spiral spoiler 300 is adjusted by a power device (such as a motor or a hydraulic device) to form a larger deflection angle with the spiral heat exchange tube 200. This dynamic adjustment can not only provide a powerful cleaning effect when needed, but also can be flexibly controlled according to actual operating conditions to avoid unnecessary energy consumption.

[0055] The structure of the power assembly 600 is as follows: it includes a transmission rod whose lower end is clamped or riveted with the corresponding horizontal slide plate 610, the transmission rod is installed on the lead screw body 630 through the corresponding lead screw nut, and the lead screw body 630 is installed on the mounting seat 640 of the upper housing 500;

[0056] The screw lever body 630 drives the driven wheel 660 installed on the screw lever body 630 to rotate through the driving wheel 680 installed on the output end of the driving motor 670.

[0057] In order to facilitate maintenance and installation, the upper housing 500 is provided with an installation box 501 of the power assembly 600 .

[0058] In addition to the above methods, the simplest way to drive the horizontal sliding 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 problems, a 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 the heat exchange efficiency.

[0059] In order to further improve, the spiral spoiler 300 has a built-in shape memory alloy wire, which is connected to the temperature control circuit (using existing technology) to realize dynamic adjustment of the spiral angle; the surface of the spoiler is integrated with piezoelectric ceramic sheets, which remove dirt through high-frequency vibration and fluid flushing. The above design greatly improves the intelligence level and cleaning efficiency of the equipment. The memory alloy can be a nickel-titanium alloy, which can not only withstand various chemical substances that may be present inside the heat exchanger, but also ensure stability and reliability under long-term operation. In addition, the high fatigue life of nickel-titanium alloy means that it can withstand multiple shape changes without damage, which is particularly important for devices that frequently perform self-cleaning operations.

[0060] The central guide rod 400 is tubular and is connected to the liquid inlet 130 and the liquid outlet 140. This design allows the central guide rod 400 to play a guiding and supporting role while also being used to improve heat exchange efficiency.

[0061] The spiral spoiler 300 is installed on the central guide rod 400 through the sliding sleeve 310. The spiral spoiler 300 and the corresponding sliding sleeve 310 are connected and fixed by more than three supporting rods 320 to maximize the fluid passing area and reduce the resistance to the liquid, thereby improving the heat exchange efficiency.

[0062] In order to reduce the resistance of the fluid passing through, the cross section of the spoiler is streamlined, and the inlet end of the heat exchange flow channel as a whole and along the corresponding flow section is arranged higher than the outlet end.

[0063] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0064] The terms "upper", "lower", "outer side", "inner side", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish the relative relationship in position if they exist, and do not need to be qualitative. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0065] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather 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 shell, the shell comprising an upper shell and a lower shell, a plurality of guide plates constituting a heat exchange flow channel are arranged in the lower shell, a heat exchange tube assembly is installed in the heat exchange flow channel, a water inlet and a water outlet are arranged at both ends of the heat exchange flow channel, and the heat exchange tube assembly is 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 comprises a spiral spoiler arranged on the inner side of the innermost spiral heat exchange tube and arranged 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 make the liquid in the heat exchange flow channel form a spiral flow state; 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 all 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 also for assisting the spiral tube group to make the liquid in the heat exchange channel form a spiral flow state.

3. The self-cleaning shell and tube heat exchanger according to claim 1, characterized in that: 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.

4. The self-cleaning shell and tube heat exchanger according to claim 3, characterized in that: 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.

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

6. The self-cleaning shell and tube heat exchanger according to claim 3, characterized in that: The power device includes a pull rod, and the spiral spoiler is connected to the cross slide plate through 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 increases, and the spiral angle near the turning point decreases.

7. The self-cleaning shell and tube heat exchanger according to claim 6, characterized in that: The power assembly includes a transmission rod whose lower end is clamped or riveted to the corresponding transverse sliding plate, 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; The screw lever body drives a driven wheel installed on the screw lever body to rotate through a driving wheel installed on the output end of the driving motor.

8. The self-cleaning shell and tube heat exchanger according to claim 7, characterized in that: The upper shell is provided with a mounting box of the power assembly.

9. The self-cleaning shell and tube heat exchanger according to claim 3, characterized in that: The central guide rod is tubular and connected to the liquid inlet and the liquid outlet; The spiral spoiler is installed on the central guide rod through a sliding sleeve, and the spiral spoiler and the corresponding sliding sleeve are connected and fixed by more than three supporting rods.

10. The self-cleaning shell and tube heat exchanger according to any one of claims 1 to 9, characterized in that: The cross section of the spoiler is streamlined; The heat exchange flow channel as a whole and along the corresponding flow section are arranged with the inlet end higher than the outlet end.

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