Waste heat utilization energy-saving heat exchanger
By introducing a flow equalization structure and a multi-stage flow rate regulation structure into the heat exchanger, the problem of thermal stratification caused by differences in fluid temperature and flow rate is solved, achieving fluid temperature uniformity and flow rate stability, thereby improving heat exchange efficiency and equipment lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-04-07
AI Technical Summary
Existing shell-and-tube heat exchangers suffer from thermal stratification due to differences in fluid temperature and flow rate when waste heat is recycled. This leads to reduced heat exchange efficiency and shortened equipment lifespan. Furthermore, the fluid control is coarse, making it difficult to achieve precise and stable flow rate regulation.
An energy-saving heat exchanger for waste heat utilization was designed. It adopts a flow equalization structure, a multi-stage flow rate regulation structure and a PLC controller. The flow rate is regulated by a flow equalization hemispherical mixing fluid, a flap structure and a conical valve structure, and combined with a buffer drive component to achieve fluid temperature uniformity and flow rate stability.
It improves the heat exchange efficiency and service life of the heat exchanger, achieves uniform fluid temperature and stable flow rate, and avoids thermal stress damage to the equipment and energy waste.
Smart Images
Figure CN121804233A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of heat exchanger technology, and in particular to an energy-saving heat exchanger that utilizes waste heat. Background Technology
[0002] In petrochemical, power metallurgy, and industrial manufacturing, shell-and-tube heat exchangers are widely used as efficient heat exchange devices for heating, cooling, and waste heat recovery of various fluids. With the advancement of the dual carbon target, the recovery of waste heat from high-temperature condensate or process fluids generated in industrial production, and its return to the heat exchanger inlet to mix with the new fluid for reuse, has become an important technical means to achieve energy conservation and emission reduction.
[0003] However, existing shell-and-tube heat exchangers face the following main technical bottlenecks when implementing waste heat recirculation: First, existing waste heat recovery systems typically introduce high-temperature return fluid directly into the shell-side fluid inlet pipe using a simple three-way conduit. Because the return fluid and the newly introduced shell-side fluid often differ significantly in temperature, density, and velocity, they struggle to merge quickly within the inlet pipe in the absence of an effective flow equalization structure, easily leading to laminar flow or thermal stratification. This not only results in uneven temperature distribution of the fluid entering the heat exchanger tube bundle, reducing overall heat exchange efficiency, but also generates alternating thermal stress at the connection between the heat exchanger tube sheet and tube bundle due to long-term localized temperature differences, shortening the equipment's lifespan.
[0004] Secondly, traditional fluid reflux control relies on ball valves or butterfly valves installed on external pipelines. When a large amount of reflux fluid needs to be introduced quickly, the valve needs to be opened at a large angle, resulting in coarse flow rate control. When a constant temperature needs to be maintained for fine adjustment, the valve is in a small opening state, resulting in extremely fast fluid flow rate, which can easily cause cavitation or turbulence, making it difficult to achieve precise and stable control of the cross-sectional area of the fluid inside the inlet pipe. Summary of the Invention
[0005] To address the aforementioned issues, this application provides a waste heat utilization energy-saving heat exchanger that achieves uniform temperature and precise, stable flow rate control of the inlet fluid.
[0006] To achieve the above objectives, the waste heat utilization energy-saving heat exchanger designed in this application includes a shell-and-tube heat exchanger, wherein a shell-side fluid inlet pipe is fixedly installed at the top of one side of the shell-and-tube heat exchanger, and a shell-side fluid outlet pipe is fixedly installed at the bottom of the other side, and further includes: The waste heat return piping system includes a bent waste heat return pipe, a return pump, and a temperature sensor, wherein the waste heat return pipe is connected between the shell-side fluid inlet pipe and the shell-side fluid outlet pipe. A flow equalization structure is installed inside the shell-side fluid inlet pipe at the connection point with the waste heat return pipe, for mixing the waste heat fluid and the shell-side fluid; A primary flow rate regulation structure is disposed inside the shell-side fluid inlet pipe and located downstream of the flow equalization structure along the fluid flow direction, for changing the cross-sectional area of the shell-side fluid inlet pipe at that location. A secondary flow rate regulation structure is disposed inside the shell-side fluid inlet pipe and downstream of the primary flow rate regulation structure along the fluid flow direction. It is used to form a narrowed fluid channel inside the shell-side fluid inlet pipe and to regulate the flow cross-sectional area of the fluid channel. The flow equalization structure, the first-stage flow rate regulation structure, and the second-stage flow rate regulation structure are distributed sequentially from top to bottom along the axial direction of the shell-side fluid inlet pipe.
[0007] Preferably, the flow equalization structure includes a flow equalization hemisphere, which is a hollow hemisphere with its top opening fixedly connected to the inner wall of the shell-side fluid inlet pipe; the spherical surface of the flow equalization hemisphere protrudes downward, and multiple spaced fluid through holes are opened through the spherical surface of the flow equalization hemisphere.
[0008] Preferably, the primary flow rate adjustment structure includes a first flapper and a second flapper symmetrically arranged on the left and right sides, and a drive assembly for driving the first flapper and the second flapper to rotate synchronously; both the first flapper and the second flapper are semi-circular plates, and the straight sides of the first flapper and the second flapper are rotatably mounted in the shell-side fluid inlet pipe through a rotating fitting, and the arcuate sides of the first flapper and the second flapper are in contact with the inner wall of the shell-side fluid inlet pipe; wherein, the tilt angle of the first flapper and the second flapper is configured to be rotatably adjustable to change the flow gap between the first flapper and the second flapper.
[0009] Preferably, the drive assembly includes a horizontal rotating shaft, a rotating cylinder, a fixed sleeve, a first electric push rod, and a transmission lifting block; the first flap is fixedly sleeved on the fixed sleeve, and the horizontal rotating shaft is fixedly inserted inside the fixed sleeve; the second flap is fixedly connected to the rotating cylinder, and the rotating cylinder is rotatably sleeved outside the horizontal rotating shaft; the ends of the horizontal rotating shaft and the rotating cylinder extend to the outside of the shell-side fluid inlet pipe, and are respectively connected to a first transmission rod and a second transmission rod; the transmission lifting block is driven to move vertically up and down by the first electric push rod, and a horizontal transmission groove is provided on the transmission lifting block for the first transmission rod and the second transmission rod to slide into each other.
[0010] Preferably, the secondary flow rate regulating structure includes a hollow valve seat and two conical valve cores; the hollow valve seat is fixed inside the shell-side fluid inlet pipe, and two coaxially arranged valve holes are opened on the side wall of the hollow valve seat; the outer wall of the hollow valve seat and the inner wall of the shell-side fluid inlet pipe are spaced apart to form the fluid channel; the two conical valve cores are slidably inserted into the two valve holes respectively, and the conical valve cores have inwardly converging frustoconical protrusions; wherein, the conical valve cores are configured to adjust the insertion depth into the valve holes to change the flow cross-sectional area of the fluid channel.
[0011] Preferably, the top of the hollow valve seat is integrally formed with a sealing guide plate, which is in the shape of an inverted cone or inclined shape with the top extending outward, and the periphery of the top of the sealing guide plate is sealed to the inner wall of the shell-side fluid inlet pipe.
[0012] Preferably, the secondary flow rate regulating structure further includes a buffer drive assembly, which includes a second electric push rod, a connecting crossbar, a limiting crossbar, and a spring; two conical valve cores are symmetrically arranged in valve holes on both sides and connected by the connecting crossbar; the second electric push rod is installed outside the pipe and drives one of the conical valve cores; the other conical valve core is connected to the limiting crossbar, which extends into an outer sleeve installed on the outside of the pipe wall, and the spring is sleeved on the limiting crossbar with its two ends abutting against the end of the limiting crossbar and the limiting ring seat inside the outer sleeve, respectively.
[0013] Preferably, the waste heat return pipeline system further includes a diversion valve assembly, the diversion valve assembly comprising: The first electric valve is located at the end of the waste heat return pipe near the shell-side fluid outlet pipe; The second electric valve is installed on the shell-side fluid outlet pipe and is located downstream of the waste heat return pipe connection. The third electric valve is located at the end of the waste heat return pipe near the shell-side fluid inlet pipe.
[0014] Preferably, the system also includes a PLC controller, which is electrically connected to the reflux pump, temperature sensor, first electric valve, second electric valve, third electric valve, first-stage flow rate regulation structure, and second-stage flow rate regulation structure, respectively, and is used to control the opening and closing of valves and the flow rate regulation based on the temperature data collected by the temperature sensor.
[0015] Preferably, the bottom end of the hollow valve seat is closed, and the bottom end of the valve hole is flush with the inner bottom wall of the hollow valve seat; the maximum diameter of the conical valve core is greater than the diameter of the valve hole.
[0016] The waste heat recovery energy-saving heat exchanger designed in this application utilizes a porous flow-equalizing hemispherical structure inside the inlet pipe to disperse and mix hot and cold fluids to eliminate thermal stratification. Combined with a downstream first-stage flapper structure that alters the flow cross-sectional area for coarse flow adjustment, and a second-stage conical valve structure that finely adjusts the cross-sectional area of the narrowed channel, it achieves graded flow velocity control. Simultaneously, the spring buffer assembly in the second-stage structure absorbs fluid impact energy and prevents valve core vibration, thereby ensuring the temperature uniformity and flow velocity stability of the fluid entering the heat exchanger tube bundle, improving the equipment's heat exchange efficiency and service life. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the waste heat utilization energy-saving heat exchanger provided in the embodiments of this application.
[0018] Figure 2 This is a cross-sectional schematic diagram of the shell-side fluid inlet provided in an embodiment of this application.
[0019] Figure 3 This is a schematic diagram of the first-stage flow rate regulation structure provided in the embodiments of this application.
[0020] Figure 4 This is a schematic diagram of the transmission connection between the first and second flip-plate components and the transmission lifting block provided in the embodiments of this application.
[0021] Figure 5 This is an exploded view of the first and second flap components provided in the embodiments of this application.
[0022] Figure 6 This is a schematic diagram of the two-stage flow rate regulation structure provided in the embodiments of this application.
[0023] Figure 7 for Figure 2 A magnified view of part A in the diagram.
[0024] The components include: 1. Shell-and-tube heat exchanger; 2. Shell-side fluid inlet pipe; 3. Shell-side fluid outlet pipe; 4. Waste heat return pipe; 5. Return pump; 6. First electric valve; 7. Second electric valve; 8. Temperature sensor; 9. Third electric valve; 10. Flow equalization hemisphere; 11. First flapper; 12. Second flapper; 13. Horizontal rotating shaft; 14. Rotating cylinder; 15. Fixed sleeve ring; 16. First transmission rod; 17. Second transmission rod; 18. Transmission lifting block; 19. Transmission transverse groove; 20. First electric push rod; 21. Hollow valve seat; 22. Sealing guide plate; 23. Valve hole; 24. Conical valve core; 25. Connecting crossbar; 26. Second electric push rod; 27. Outer sleeve; 28. Limiting transverse slide bar; 29. Limiting ring seat; 30. Spring component. Detailed Implementation
[0025] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.
[0026] Please see Figures 1 to 7 This application provides a waste heat utilization energy-saving heat exchanger, which mainly includes a shell-and-tube heat exchanger 1, a waste heat return pipeline system, a flow equalization structure, a primary flow rate regulation structure, and a secondary flow rate regulation structure.
[0027] Specifically, the shell-and-tube heat exchanger 1 serves as the heat exchange body, with a vertically upward-facing shell-side fluid inlet pipe 2 fixedly installed at the top of one side and a shell-side fluid outlet pipe 3 fixedly installed at the bottom of the other side. In actual operation, high-temperature fluid or mixed fluid is introduced through the shell-side fluid inlet pipe 2, undergoes heat exchange through the tube bundle inside the heat exchanger (not shown in the figure), and is then discharged through the shell-side fluid outlet pipe 3.
[0028] To achieve efficient recovery and recycling of waste heat from fluids, the waste heat return pipeline system includes a bent waste heat return pipe 4, a return pump 5, and a temperature sensor 8. Among them: The two ends of the waste heat return pipe 4 are respectively connected between the shell-side fluid inlet pipe 2 and the shell-side fluid outlet pipe 3, thereby forming a bypass circulation channel outside the heat exchanger.
[0029] The temperature sensor 8 is fixedly installed above the connection between the shell-side fluid outlet pipe 3 and the waste heat return pipe 4, with its probe extending into the pipe. Preferably, the temperature sensor 8 is a PT100 platinum resistance temperature sensor with fast response and high accuracy, used to monitor the temperature data of the discharged fluid in real time, so as to provide feedback signals for subsequent control.
[0030] The reflux pump 5 is fixedly installed on one side of the shell-side fluid outlet pipe 3, or installed on the waste heat reflux pipe 4, to provide the power head required for fluid reflux and pump the fluid at the outlet back to the inlet.
[0031] like Figure 2 , Figure 3 As shown, the flow equalization structure, the first-stage flow rate regulation structure, and the second-stage flow rate regulation structure are distributed sequentially from top to bottom along the axial direction of the shell-side fluid inlet pipe 2.
[0032] Flow equalization structure: This structure is located inside the shell-side fluid inlet pipe 2, corresponding to the connection point with the waste heat return pipe 4. Situated at the very front of the fluid confluence, this structure receives and mixes the waste heat fluid introduced by the waste heat return pipe 4 with the fresh shell-side fluid introduced upstream of the inlet pipe, eliminating temperature stratification between the two fluid streams through physical dispersion.
[0033] The first-stage flow rate regulation structure is located within the shell-side fluid inlet pipe 2 and downstream of the flow equalization structure along the fluid flow direction. This structure serves as a coarse adjustment unit, used to change the cross-sectional area of the shell-side fluid inlet pipe 2 at this location. That is, by adjusting the flow area over a wide range, it adapts to the total flow rate requirements under different operating conditions and performs preliminary rectification of the mixed fluid after flow equalization.
[0034] The secondary velocity regulation structure is located within the shell-side fluid inlet pipe 2 and downstream of the primary velocity regulation structure along the fluid flow direction, i.e., near the inlet of the shell-and-tube heat exchanger 1. This structure serves as a fine-tuning and flow stabilization unit. Its design creates a narrowed fluid channel within the shell-side fluid inlet pipe 2 and allows adjustment of the cross-sectional area of this channel. Specifically, the secondary velocity regulation structure forces fluid convergence by constructing a narrowed channel, and combined with fine-tuning of the cross-sectional area, eliminates fluid pulsation, ensuring that the fluid ultimately entering the shell-and-tube heat exchanger 1 has a uniform and stable velocity.
[0035] The above structural layout enables a fluid processing flow of mixing, coarse adjustment, and fine adjustment, which effectively improves waste heat utilization efficiency and the operational stability of the heat exchanger.
[0036] In some embodiments, such as Figure 1 As shown, the waste heat return pipeline system also includes a diversion valve assembly, which includes: The first electric valve 6 is located at one end of the waste heat return pipe 4 near the shell-side fluid outlet pipe 3; its function is to control whether the high-temperature fluid enters the return pipe.
[0037] The second electric valve 7 is installed on the shell-side fluid outlet pipe 3, and is located downstream of the connection between the waste heat return pipe 4 and the shell-side fluid outlet pipe 3. Its function is to control whether the fluid is directly discharged to the outside.
[0038] The third electric valve 9 is located at one end of the waste heat return pipe 4 near the shell-side fluid inlet pipe 2, i.e., the end of the return pipe. Its function is to control whether the return fluid is injected into the inlet pipe and to prevent the fluid in the shell-side inlet pipe from flowing back.
[0039] The valves mentioned above are preferably electric shut-off valves or electric ball valves, which have the characteristics of fast response and good sealing performance. Furthermore, through the opening and closing of the valves, the heat exchanger can be flexibly switched between normal direct discharge mode and waste heat recovery mode.
[0040] In some embodiments, a PLC controller is also included. The PLC controller can be electrically connected to the reflux pump 5, the temperature sensor 8, the first electric valve 6, the second electric valve 7, the third electric valve 9, the primary flow rate regulation structure, and the secondary flow rate regulation structure via signal lines, respectively, for controlling the opening and closing of valves and regulating flow rate according to the temperature data collected by the temperature sensor.
[0041] In practical implementation, the input terminal of the PLC controller is connected to the temperature sensor 8 to receive real-time fluid temperature signals; while the output terminal of the PLC controller is connected to the reflux pump 5, the first electric valve 6, the second electric valve 7, and the third electric valve 9, respectively, as well as to the first electric actuator 20 in the first-stage flow rate regulation structure and the second electric actuator 26 in the second-stage flow rate regulation structure. The specific control strategy is as follows: Operating Condition 1: Waste Heat Recovery Mode When temperature sensor 8 detects that the temperature of the fluid discharged from shell-side fluid outlet pipe 3 is higher than the preset heat recovery threshold (e.g., 80°C), the PLC controller executes the recovery procedure: The second electric valve 7 is closed to cut off the direct discharge channel; the first electric valve 6 and the third electric valve 9 are opened simultaneously to open the waste heat return pipe 4; the return pump 5 is started to pump the high-temperature fluid back into the shell-side fluid inlet pipe 2; at the same time, the PLC sends instructions to the first electric push rod 20 and the second electric push rod 26 according to the real-time temperature difference or the set flow rate to adjust the flap angle and the opening of the cone valve to ensure that the return fluid enters at a suitable flow rate.
[0042] Operating Condition 2: Direct Emission Mode When temperature sensor 8 detects that the fluid temperature is lower than the preset heat recovery threshold (indicating low waste heat value or no need for recovery), the PLC controller executes the direct discharge program: The first electric valve 6 and the third electric valve 9 are closed, and the reflux pump 5 is stopped to isolate the waste heat reflux system from the main system; the second electric valve 7 is fully opened to allow the fluid to be discharged directly through the shell-side fluid outlet pipe 3.
[0043] Through the cooperation of the above-mentioned diversion valve assembly and PLC controller, this heat exchanger can automatically determine whether to perform waste heat recovery according to the actual working conditions, which not only avoids the energy waste caused by low temperature fluid reflux, but also maximizes the utilization of high temperature waste heat.
[0044] In some embodiments, such as Figure 3 , Figure 6 As shown, the flow equalization structure includes a flow equalization hemisphere 10, which is a hollow hemisphere with its top opening fixedly connected to the inner wall of the shell-side fluid inlet pipe 2. In the specific manufacturing process, the top edge of the flow equalization hemisphere 10 can be seamlessly sealed and fixed to the inner wall of the pipe along the circumferential direction by welding or flange connection, so that the flow equalization hemisphere 10 completely covers the cross-section of the shell-side fluid inlet pipe 2, becoming the necessary channel for the fluid to flow downward.
[0045] Meanwhile, the spherical surface of the flow equalization hemisphere 10 protrudes downwards, with the concave surface facing upstream and the convex surface facing downstream, effectively dispersing fluid impact stress and reducing the risk of structural deformation. Furthermore, multiple spaced fluid through-holes are perforated on the spherical surface of the flow equalization hemisphere 10. These through-holes can be circular, elliptical, or elongated, preferably evenly distributed in an array or radial pattern across the entire spherical surface. When the main fluid, mixed with waste heat fluid, flows towards the flow equalization hemisphere 10, the fluid first converges in the inner cavity of the hemisphere. Subsequently, under the action of fluid pressure, a large stream of fluid is forced out through these tiny fluid through-holes, cutting the potentially stratified large-flow fluid into several tiny jets. These jets collide and converge below the flow equalization hemisphere 10, on the convex side, allowing the fluid to achieve uniform mixing over a short distance. This provides a uniformly temperatured and relatively symmetrical fluid input for the subsequent primary flow rate regulation structure, effectively avoiding a decrease in heat exchange efficiency or thermal stress damage to the equipment caused by localized temperature differences.
[0046] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 As shown, the primary flow rate adjustment structure includes a first flapper 11 and a second flapper 12 symmetrically arranged on the left and right, and a drive assembly for driving the first flapper 11 and the second flapper 12 to rotate synchronously; the first flapper 11 and the second flapper 12 are both semi-circular plates, and the straight sides of the first flapper 11 and the second flapper 12 are rotatably installed in the shell-side fluid inlet pipe 2 through a rotating fitting, and the arcuate sides of the first flapper 11 and the second flapper 12 are in contact with the inner wall of the shell-side fluid inlet pipe 2; wherein, the tilt angle of the first flapper 11 and the second flapper 12 is configured to be rotatably adjustable to change the flow gap between the first flapper 11 and the second flapper 12.
[0047] Specifically, the straight edge side, i.e. the diameter side, of the first flap 11 and the second flap 12 is rotatably mounted on the central axis position of the shell fluid inlet pipe 2 through a rotating fitting, while the arc side side of both is adapted to and fits the inner wall contour of the shell fluid inlet pipe 2.
[0048] Closed state: When the first flap 11 and the second flap 12 are rotated to the horizontal position, the arc edge is in contact with the pipe wall and the straight edge is close to each other, almost completely blocking the fluid passage.
[0049] Adjustment state: The tilt angle of the first flap 11 and the second flap 12 is rotatably adjustable. By changing the opening angle of the first flap 11 and the second flap 12, the size of the V-shaped or inverted V-shaped flow gap formed between the first flap 11 and the second flap 12 can be changed, thereby changing the flow cross-sectional area at that position and realizing the adjustment of the flow rate.
[0050] In this embodiment, as Figure 3 , Figure 4 , Figure 5 As shown, the drive assembly includes a horizontal rotating shaft 13, a rotating cylinder 14, a fixed sleeve ring 15, a first electric push rod 20, and a transmission lifting block 18.
[0051] The first flapper 11 is fixedly sleeved on the fixed sleeve 15, and a horizontal rotating shaft 13 is fixedly inserted inside the fixed sleeve 15, that is, the first flapper 11 rotates with the horizontal rotating shaft 13; correspondingly, the second flapper 12 is fixedly connected to a rotating cylinder 14, which is a hollow tube and is rotatably sleeved on the outside of the horizontal rotating shaft 13; wherein, the fixed sleeve 15 and the rotating cylinder 14 are arranged alternately along the axial direction without interfering with each other, and the horizontal rotating shaft 13 serves as a spindle, which is both the drive shaft of the first flapper 11 and the support shaft of the second flapper 12, so as to effectively save the flow space in the pipeline.
[0052] The ends of the horizontal rotating shaft 13 and the rotating cylinder 14 extend to the outside of the shell-side fluid inlet pipe 2 and are respectively connected to the first transmission rod 16 and the second transmission rod 17; the transmission lifting block 18 is driven to rise and fall vertically by the first electric push rod 20, and the transmission lifting block 18 is provided with a horizontal transmission groove 19 for the first transmission rod 16 and the second transmission rod 17 to slide and insert into each other, so as to convert a single power source into two rotational actions in opposite directions.
[0053] When the PLC controller issues an adjustment command to drive the first electric push rod 20 to extend or retract, it drives the transmission lifting block 18 to rise and fall vertically. Since the first transmission rod 16 and the second transmission rod 17 are confined within the transmission transverse groove 19, the vertical movement of the transmission lifting block 18 forces these two transmission rods to displace in the vertical direction. At the same time, the rotation of the transmission rods around the axis will generate a horizontal displacement component, which is eliminated by the free sliding of the rod ends within the transmission transverse groove 19. Finally, the vertical movement is converted into the rotation of the first transmission rod 16 and the second transmission rod 17 around the axis. Due to the symmetrical arrangement of the two rods and the axis, the horizontal rotating shaft 13 (i.e., the first flap 11) and the rotating cylinder 14 (i.e., the second flap 12) will rotate synchronously in opposite directions, thereby realizing the symmetrical opening or closing of the flaps. This mechanism only requires one motor to control two flaps, and has a compact structure and good synchronization.
[0054] In some embodiments, such as Figure 6 , Figure 7 As shown, the secondary flow rate regulation structure includes a hollow valve seat 21 and two conical valve cores 24; the bottom end of the hollow valve seat 21 is closed, and the bottom end of the valve hole 23 is flush with the inner bottom wall of the hollow valve seat 21; the maximum diameter of the conical valve core 24 is larger than the diameter of the valve hole 23.
[0055] The hollow valve seat 21 is fixed inside the shell-side fluid inlet pipe 2, and two coaxially arranged valve holes 23 are opened on the side wall of the hollow valve seat 21; an annular gap is maintained between the outer wall of the hollow valve seat 21 and the inner wall of the shell-side fluid inlet pipe 2, thereby forming the fluid channel; the two conical valve cores 24 are slidably inserted into the two valve holes 23 respectively, so that the fluid in the outer annular channel can enter the internal cavity of the hollow valve seat 21 through the two valve holes; and the conical valve core 24 has an inwardly converging frustum-shaped protrusion; wherein, the conical valve core 24 is configured to adjust the insertion depth into the valve hole 23 to change the flow cross-sectional area of the fluid channel, that is, the deeper the valve core is inserted inward, the larger the area occupied by the frustum-shaped protrusion in the valve hole 23, and the smaller the effective flow cross-sectional area; conversely, the deeper the valve core is inserted inward, the larger the area occupied by the frustum-shaped protrusion in the valve hole 23, and the smaller the effective flow cross-sectional area; and vice versa.
[0056] In some embodiments, such as Figure 6 , Figure 7 As shown, the top of the hollow valve seat 21 is integrally formed with a sealing guide plate 22. The sealing guide plate 22 is an inverted cone or inclined shape with the top extending outward. The periphery of the top of the sealing guide plate 22 is sealed and connected to the inner wall of the shell fluid inlet pipe 2, so as to completely block the fluid in the shell fluid inlet pipe 2 above the hollow valve seat 21, forcing all the fluid to be diverted to the outer annular channel along the inverted cone inclined surface.
[0057] In some embodiments, such as Figure 7 As shown, the secondary flow rate adjustment structure also includes a buffer drive assembly, which includes a second electric push rod 26, a connecting crossbar 25, a limiting crossbar 28, and a spring 30.
[0058] Specifically, the two conical valve cores 24 are symmetrically arranged in the valve holes 23 on both sides and connected by a connecting crossbar 25 to form an integral motion unit; the second electric push rod 26 is installed outside the pipe and drives one of the conical valve cores 24; the other conical valve core 24 is connected to the limiting crossbar 28, the limiting crossbar 28 extends into the outer sleeve 27 installed on the outside of the pipe wall, and the spring 30 is sleeved on the limiting crossbar 28 and its two ends respectively abut against the end of the limiting crossbar 28 and the limiting ring seat 29 inside the outer sleeve 27.
[0059] When the second electric push rod 26 drives the valve core to move left and right for adjustment, the limiting slide bar 28 slides synchronously in the outer sleeve 27, compressing or releasing the spring 30. The spring 30 always applies a preload or restoring force to the valve core assembly. This elastic force can effectively absorb the impact energy caused by fluid pressure pulsation on the valve core, eliminate transmission gaps, ensure that the valve core maintains dynamic balance, avoid mechanical chatter, and thus ensure that the fluid velocity entering the heat exchanger is absolutely stable.
[0060] The waste heat utilization energy-saving heat exchanger provided in this application embodiment utilizes a porous flow-equalizing hemispherical structure inside the inlet pipe to disperse and mix hot and cold fluids to eliminate thermal stratification; combined with a downstream first-stage flap structure to change the flow cross-sectional area for coarse flow adjustment, and a second-stage conical valve structure to finely adjust the cross-sectional area of the narrowed channel, it achieves graded flow velocity control; at the same time, the spring buffer component in the second-stage structure absorbs fluid impact energy and prevents valve core vibration, thereby ensuring the temperature uniformity and flow velocity stability of the fluid entering the heat exchanger tube bundle, improving the heat exchange efficiency and service life of the equipment.
[0061] In the description of this application, it should be noted that the terms "vertical", "up", "down", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0062] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0063] Finally, it should be noted that the above descriptions are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A waste heat utilization energy-saving heat exchanger, comprising a shell-and-tube heat exchanger, wherein a shell-side fluid inlet pipe is fixedly installed at the top of one side of the shell-and-tube heat exchanger, and a shell-side fluid outlet pipe is fixedly installed at the bottom of the other side, characterized in that, Also includes: The waste heat return piping system includes a bent waste heat return pipe, a return pump, and a temperature sensor, wherein the waste heat return pipe is connected between the shell-side fluid inlet pipe and the shell-side fluid outlet pipe. A flow equalization structure is installed inside the shell-side fluid inlet pipe at the connection point with the waste heat return pipe, for mixing the waste heat fluid and the shell-side fluid; A primary flow rate regulation structure is disposed inside the shell-side fluid inlet pipe and located downstream of the flow equalization structure along the fluid flow direction, for changing the cross-sectional area of the shell-side fluid inlet pipe at that location. A secondary flow rate regulation structure is disposed inside the shell-side fluid inlet pipe and downstream of the primary flow rate regulation structure along the fluid flow direction. It is used to form a narrowed fluid channel inside the shell-side fluid inlet pipe and to regulate the flow cross-sectional area of the fluid channel. The flow equalization structure, the first-stage flow rate regulation structure, and the second-stage flow rate regulation structure are distributed sequentially from top to bottom along the axial direction of the shell-side fluid inlet pipe.
2. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The flow equalization structure includes a flow equalization hemisphere, which is a hollow hemisphere with its top opening fixedly connected to the inner wall of the shell-side fluid inlet pipe. The spherical surface of the flow equalization hemisphere protrudes downwards, and multiple spaced fluid through holes are opened through the spherical surface of the flow equalization hemisphere.
3. The waste heat utilization energy-saving heat exchanger according to claim 3, characterized in that, The primary flow rate adjustment structure includes a first flap and a second flap symmetrically arranged on the left and right sides, and a drive assembly for driving the first flap and the second flap to rotate synchronously; both the first flap and the second flap are semi-circular plates, and the straight sides of the first flap and the second flap are rotatably mounted in the shell-side fluid inlet pipe through a rotating fitting, and the arc sides of the first flap and the second flap are in contact with the inner wall of the shell-side fluid inlet pipe; wherein, the tilt angle of the first flap and the second flap is configured to be rotatably adjustable to change the flow gap between the first flap and the second flap.
4. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The drive assembly includes a horizontal rotating shaft, a rotating cylinder, a fixed sleeve, a first electric push rod, and a transmission lifting block; the first flap is fixedly sleeved on the fixed sleeve, and the horizontal rotating shaft is fixedly inserted inside the fixed sleeve; the second flap is fixedly connected to the rotating cylinder, and the rotating cylinder is rotatably sleeved outside the horizontal rotating shaft; the ends of the horizontal rotating shaft and the rotating cylinder extend to the outside of the shell-side fluid inlet pipe, and are respectively connected to a first transmission rod and a second transmission rod; the transmission lifting block is driven to move vertically up and down by the first electric push rod, and a horizontal transmission groove is provided on the transmission lifting block for the first transmission rod and the second transmission rod to slide into each other.
5. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The secondary flow rate regulation structure includes a hollow valve seat and two conical valve cores. The hollow valve seat is fixed inside the shell-side fluid inlet pipe, and two coaxially arranged valve holes are opened on the side wall of the hollow valve seat. The fluid channel is formed by the gap between the outer wall of the hollow valve seat and the inner wall of the shell-side fluid inlet pipe. The two conical valve cores are slidably inserted into the two valve holes, and the conical valve cores have inwardly converging frustoconical protrusions. The conical valve cores are configured to adjust the insertion depth into the valve holes to change the flow cross-sectional area of the fluid channel.
6. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The top of the hollow valve seat is integrally formed with a sealing guide plate, which is an inverted cone or inclined shape with the top extending outward, and the periphery of the top of the sealing guide plate is sealed to the inner wall of the shell-side fluid inlet pipe.
7. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The secondary flow rate regulation structure also includes a buffer drive assembly, which includes a second electric push rod, a connecting crossbar, a limiting crossbar, and a spring. The two conical valve cores are symmetrically arranged in the valve holes on both sides and connected by the connecting crossbar. The second electric push rod is installed outside the pipe and drives one of the conical valve cores. The other conical valve core is connected to the limiting crossbar, which extends into an outer sleeve installed on the outside of the pipe wall. The spring is sleeved on the limiting crossbar and its two ends abut against the end of the limiting crossbar and the limiting ring seat inside the outer sleeve, respectively.
8. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, The waste heat return piping system also includes a diversion valve assembly, which comprises: The first electric valve is located at the end of the waste heat return pipe near the shell-side fluid outlet pipe; The second electric valve is installed on the shell-side fluid outlet pipe and is located downstream of the waste heat return pipe connection. The third electric valve is located at the end of the waste heat return pipe near the shell-side fluid inlet pipe.
9. The waste heat utilization energy-saving heat exchanger according to claim 1, characterized in that, It also includes a PLC controller, which is electrically connected to the reflux pump, temperature sensor, first electric valve, second electric valve, third electric valve, first-stage flow rate regulation structure and second-stage flow rate regulation structure, respectively, and is used to control the opening and closing of valves and the flow rate regulation according to the temperature data collected by the temperature sensor.
10. The waste heat utilization energy-saving heat exchanger according to claim 10, characterized in that, The bottom end of the hollow valve seat is closed, and the bottom end of the valve hole is flush with the inner bottom wall of the hollow valve seat; the maximum diameter of the conical valve core is larger than the diameter of the valve hole.