A transverse cyclone heat exchanger for high vacuum heat pump rectification system

Abstract

This invention belongs to the field of chemical equipment technology and discloses a transverse swirl heat exchanger for a high-vacuum heat pump distillation system. The heat exchanger body includes a heat exchange shell, which comprises a cylindrical shell, an upper tube box, and a lower tube box. Swirl heat exchange tubes are installed inside the cylindrical shell, and each tube inlet has swirl vanes. An inclined guide plate is installed on the upper tube box, allowing the material entering through the material inlet to be more evenly distributed into the swirl heat exchange tubes under the action of the guide plate. In this invention, the material flowing through the swirl vanes rotates to quickly achieve turbulence, increasing the material velocity and turbulence level, effectively improving the heat transfer coefficient and enhancing the heat transfer effect. The inclined guide plate allows the material to be evenly distributed into each swirl heat exchange tube, avoiding localized overheating and dry wall problems caused by uneven liquid distribution, and reducing the risk of scaling and crystallization. This transverse swirl heat exchanger can be used in the reboiler of a high-vacuum heat pump distillation system.

Description

Technical Field

[0001] This invention relates to a transverse swirl heat exchanger for a high-vacuum heat pump distillation system, belonging to the field of chemical equipment technology. Background Technology

[0002] A heat exchanger is a key energy-saving device for heat exchange. Its main structure includes a fluid heat transfer structure and a fluid distribution structure, and it is widely used in industries such as petroleum, chemical, and pharmaceutical.

[0003] Heat pump distillation is a distillation technology that achieves energy saving through energy recycling. Its core principle is to transfer the condensation heat of the vapor at the top of the distillation column to the material in the bottom of the column as a reboiling heat source, which can significantly reduce the system's energy consumption. Its core energy-consuming equipment is the compressor.

[0004] In high-vacuum heat pump distillation systems, the reboiler operates at a low pressure, and the materials processed are often heat-sensitive substances. If a conventional vertical shell-and-tube heat exchanger is used in the reboiler, the static liquid column formed by the material in the tubes will cause the pressure at the bottom of the liquid column to rise, thus making the bubble point temperature of the material at that point higher than the reboiler operating temperature. This may not only trigger side reactions such as decomposition and polymerization of heat-sensitive materials, but more importantly, in order to overcome the static head and provide a sufficient heat transfer temperature difference, the heat pump system must provide heat source steam with a higher temperature and pressure. This leads to a sharp increase in the compressor compression ratio and power consumption, severely reducing the energy-saving benefits of heat pump distillation.

[0005] To address the aforementioned issues, existing technologies for reboilers in towers often employ vertical falling film evaporators. However, falling film evaporators rely on gravity-based film distribution, requiring the material to form a uniform liquid film on the inner wall of the heat exchange tubes. This presents the following drawbacks: 1. Low material flow rate and generally low heat transfer coefficient; 2. High requirements for the design and operational stability of the liquid distributor. Uneven distribution can easily lead to localized overheating or dry wall phenomena, resulting in scaling and crystallization of the material; 3. Falling film evaporators have a relatively high vaporization rate. To ensure effective film distribution, large-diameter heat exchange tubes are typically used, generally not less than φ38mm, further limiting the heat transfer effect. Additionally, for heat exchangers with the same heat exchange area, larger diameter heat exchangers have a larger equipment volume and require a larger footprint. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a transverse vortex heat exchanger for high-vacuum heat pump distillation systems.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A transverse swirl heat exchanger for a high vacuum heat pump distillation system includes a heat exchanger body, the heat exchanger body includes a heat exchange shell, the heat exchange shell is provided with a material inlet, a material outlet, a gas phase inlet and a condensate outlet, the heat exchanger body is horizontally arranged, the heat exchange shell includes a cylinder, an upper tube box provided at one end of the cylinder and a lower tube box provided at the other end of the cylinder, the cylinder is provided with a plurality of parallel swirl heat exchange tubes, the diameter of the swirl heat exchange tubes is less than or equal to 25mm, and the material inlet is provided on the upper tube box; The swirl heat exchanger tube is provided with swirl vanes at the tube inlet; The upper tube box is equipped with a guide plate, which is inclined so that the material entering through the material inlet can be more evenly distributed into the vortex heat exchange tube under the guiding effect of the guide plate.

[0008] The beneficial effects of this invention are as follows: The horizontal arrangement eliminates the static liquid column pressure of the vertical heat exchanger, avoiding the rise in bubble point temperature of the material in the tower bottom due to increased static liquid column pressure. This prevents side reactions such as decomposition and polymerization of heat-sensitive materials, and reduces the temperature and pressure of the heat source steam required by the heat pump system, while retaining the energy-saving advantages of heat pump distillation. The swirl vanes installed at the inlet of the swirl heat exchanger tube guide the material entering the heat exchanger tube to form a swirling flow. The material rotates and generates strong shear force as it flows through the swirl vanes, quickly achieving turbulence, increasing the flow velocity and turbulence level of the material, effectively improving the heat transfer coefficient and enhancing the heat transfer effect. This heat exchanger operates under conditions of low vaporization rate and large circulation volume. The vaporization rate is controlled between 2% and 5%. The small pipe diameter combined with a large circulation volume ensures that the fluid inside the heat exchange tube maintains a high flow velocity. With the help of swirl vanes, a high heat transfer coefficient inside the tube is achieved. It also has self-cleaning capabilities. The rapid flow can also produce a good self-cleaning flushing effect on the tube wall, reducing scaling and extending the operating cycle. The inclined guide plate can make the material more evenly distributed into each swirl heat exchange tube, avoiding local overheating and dry wall problems caused by uneven liquid distribution, and reducing the risk of material scaling and crystallization. The transverse swirl heat exchanger can operate as a reboiler in the high vacuum heat pump distillation system, improving the stability and economy of the high vacuum heat pump distillation system.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, the angle between the guide plate and the axis of the heat exchanger body is 30°-60°, and the length of the guide plate is 60%-90% of the inner diameter of the upper tube box.

[0011] The beneficial effect of adopting the above-mentioned further solution is that the baffle plate can uniformly guide the feed fluid to the inlet of each swirl heat exchanger tube, thus meeting the requirement of uniform flow distribution in each swirl heat exchanger tube as much as possible. While ensuring the flow guiding effect, sufficient space is left for the fluid to complete buffer distribution, avoiding flow channel congestion due to excessively long baffle plates, and also preventing insufficient flow guiding effect due to excessively short baffle plates. This further improves the uniformity of fluid distribution in the upper tube box, ensures balanced feed flow in each heat exchanger tube, and stabilizes heat exchange efficiency.

[0012] Furthermore, the swirl vanes are provided in multiples, and the multiple swirl vanes are uniformly arranged circumferentially on the inner wall of the tube inlet of the swirl heat exchange tube.

[0013] The beneficial effect of adopting the above-mentioned further scheme is that multiple swirl vanes are uniformly arranged circumferentially. When the fluid flows through it axially, it is forced to generate relative movement to form a strong secondary flow, which greatly enhances the mass and energy exchange between the fluid core region and the near-wall region, reduces the heat transfer resistance of the laminar flow layer, and achieves heat transfer enhancement.

[0014] Furthermore, the swirl vane is positioned at a distance of 50mm-150mm from the inlet of the swirl heat exchange tube.

[0015] The beneficial effect of adopting the above-mentioned further scheme is that multiple swirling heat exchanger tubes are arranged in parallel, and each heat exchanger tube has swirling vanes on the inner wall of its inlet, which are arranged at a distance of 50mm-150mm from the tube inlet. After the fluid enters the heat exchanger tube and reaches a stable flow state, it rotates and generates strong shear force as it flows through the swirling vanes, so as to quickly achieve turbulence and enhance heat transfer. The swirling vanes are evenly distributed circumferentially, and two rings can be arranged along the axial direction at intervals of 2-4 times the tube diameter. Depending on the tube diameter, the number of swirling vanes in each ring can be 3-6.

[0016] Furthermore, the swirl heat exchange tube is a twisted tube.

[0017] The beneficial effects of adopting the above-mentioned further scheme are that the swirl heat exchange tube adopts a micro-twisted tube. On the one hand, the pressure drop is small when the fluid flows through it, which is suitable for application conditions with low vaporization rate and large circulation volume. On the other hand, a spiral twisted flow channel can be formed inside the tube, so that the fluid flow direction near the tube wall can change periodically, further enhancing the disturbance and mixing of laminar fluid and improving heat transfer performance.

[0018] Furthermore, the swirl heat exchanger tube includes a straight section located at the tube inlet and the tube outlet, and a twisted section located between the tube inlet and the tube outlet. The twisted section is located between the two straight sections, and the cross-section of the twisted section of the swirl heat exchanger tube is an elliptical structure with the ratio of the major axis to the minor axis of the elliptical structure being 1.2-1.3.

[0019] The beneficial effect of adopting the above-mentioned further scheme is that while highlighting the increase in the degree of fluid turbulence in the swirl heat exchanger tube, the flow resistance will not increase significantly. It enhances the heat exchange effect while controlling the fluid pressure drop, and is suitable for the heat exchange requirements of high vacuum heat pump distillation system.

[0020] Furthermore, the heat exchanger body is arranged horizontally, and the axis of the heat exchanger body is parallel to the horizontal plane.

[0021] The beneficial effect of adopting the above-mentioned further scheme is that when the material inside the heat exchange tube is conventional, a horizontally arranged heat exchanger can be selected. The horizontally arranged heat exchanger can eliminate the static liquid column formed by the vertical swirl heat exchange tube. The material pressure at various points inside the swirl heat exchange tube is basically equal to the pressure of the column bottom in the high vacuum heat pump distillation system, and the material temperature is consistent with the boiling point temperature of the column bottom.

[0022] Furthermore, the heat exchanger body is inclined downward along the material flow direction inside the swirl heat exchange tube, and the downward inclination angle of the heat exchanger body is 1°-5°.

[0023] The beneficial effects of adopting the above-mentioned further scheme are that when the material in the heat exchange tube is prone to crystallization, the inclined heat exchanger is preferred; the slightly downward inclined heat exchanger can eliminate the static liquid column and facilitate the return of the gas-liquid two-phase flow to the tower bottom by gravity after leaving the heat exchanger; the inclined heat exchange tube body not only helps the material to return to the tower bottom quickly, but also helps the material in the heat exchange tube to be discharged quickly when the machine is stopped.

[0024] Furthermore, the diameter of the straight section of the swirl heat exchanger tube is 15mm, 19mm, or 25mm.

[0025] The beneficial effect of adopting the above-mentioned further scheme is that the swirl heat exchanger tube uses a small diameter tube. The diameter of the straight section of the swirl heat exchanger tube can be selected as φ15, φ19 or φ25mm. The small diameter swirl heat exchanger tube can better highlight the strengthening effect of the swirl vanes and the micro-twisted structure, and achieve more complete radial mixing between the turbulent enhanced laminar fluid and the turbulent body in the center of the tube, thereby achieving a better heat transfer enhancement effect.

[0026] Furthermore, the material inlet is located at the bottom of the upper tube box, and the upper end of the guide plate is connected to the upper side of the inner wall of the upper tube box.

[0027] The beneficial effect of adopting the above-mentioned further solution is that the material entering the upper tube box can be more evenly distributed into each swirl heat exchange tube under the guiding action of the guide plate, ensuring that all swirl heat exchange tubes in the heat exchanger can fully participate in heat exchange. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the swirl heat exchanger tube of the present invention; Figure 3 for Figure 2 A schematic diagram of the right-side view structure; Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention; In the diagram, 1 is the material inlet; 2 is the material outlet; 3 is the gas inlet; 4 is the condensate outlet; 5 is the upper tube box; 6 is the heat exchange shell; 7 is the lower tube box; 8 is the guide plate; 9 is the swirl heat exchange tube; 10 is the baffle plate; and 11 is the swirl vane. Detailed Implementation

[0029] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0030] Example 1 like Figures 1-3 As shown, a transverse swirl heat exchanger for a high-vacuum heat pump distillation system includes a heat exchanger body, which includes a heat exchange shell 6. The heat exchange shell 6 is provided with a material inlet 1, a material outlet 2, a gas phase inlet 3, and a condensate outlet 4. The heat exchanger body is horizontally arranged. The heat exchange shell 6 includes a cylinder, an upper tube box 5 located at one end of the cylinder, and a lower tube box 7 located at the other end of the cylinder. The cylinder is provided with a plurality of parallel swirl heat exchange tubes 9. The diameter of the swirl heat exchange tubes 9 is less than or equal to 25 mm. The material inlet 1 is located on the upper tube box 5. The swirl heat exchange tube 9 is provided with a swirl vane 11 at the tube inlet; The upper tube box 5 is provided with a guide plate 8, which is inclined so that the material entering through the material inlet 1 can be more evenly distributed into the swirl heat exchange tube 9 under the guiding action of the guide plate 8.

[0031] The angle between the guide plate 8 and the axis of the heat exchanger body is 30°-60°, and the length of the guide plate 8 is 60%-90% of the inner diameter of the upper tube box 5. The guide plate 8 is designed to uniformly guide the feed fluid to the inlet of each swirl heat exchange tube 9, thus meeting the requirement of uniform flow distribution in each swirl heat exchange tube 9 as much as possible. While ensuring the guiding effect, sufficient space is left for the fluid to complete buffer distribution, avoiding flow channel congestion due to excessive length of the guide plate 8, and also preventing insufficient guiding effect due to excessive length. This further improves the uniformity of fluid distribution in the upper tube box 5, ensures balanced feed flow in each heat exchange tube, and stabilizes heat exchange efficiency.

[0032] Multiple swirl vanes 11 are provided, and the multiple swirl vanes 11 are uniformly arranged circumferentially on the inner wall of the inlet of the swirl heat exchange tube 9. When the fluid flows axially through the multiple swirl vanes 11, they are forced to move relative to each other, forming a strong secondary flow, which greatly enhances the mass and energy exchange between the fluid core region and the near-wall region, reduces the heat transfer resistance of the laminar layer, and achieves heat transfer enhancement.

[0033] The swirl vanes 11 are positioned 50mm-150mm from the inlet of the swirl heat exchange tube 9. Multiple swirl heat exchange tubes 9 are arranged in parallel, and each tube 9 has swirl vanes 11 on its inner wall at the inlet. After the fluid enters the heat exchange tube and reaches a stable flow state, it rotates and generates strong shear force as it flows past the swirl vanes 11, thus rapidly achieving turbulence and enhancing heat transfer.

[0034] The swirl vanes 11 are uniformly distributed circumferentially, and can be arranged in two rings at 2-4 times the pipe diameter along the axial direction. Depending on the pipe diameter of the swirl heat exchanger tube 9, the number of swirl vanes 11 in each ring can be 3-6. The inner wall of the inlet of each swirl heat exchanger tube 9 is provided with circumferentially uniformly distributed swirl vanes 11. When the fluid flows through the swirl vanes 11, it rotates and generates strong shear force, which disrupts the laminar layer and enhances the degree of turbulence.

[0035] like Figure 2 As shown, the swirl heat exchanger tube 9 is a twisted tube. The twisted tube is a micro-twisted tube, which has the following advantages: on the one hand, the pressure drop is small when the fluid flows through it, making it suitable for applications with low vaporization rate and large circulation volume; on the other hand, a spiral twisted flow channel can be formed inside the tube, so that the fluid flow direction near the tube wall can change periodically, further enhancing the disturbance and mixing of the laminar layer and improving the heat transfer performance.

[0036] The swirl heat exchanger tube 9 includes straight sections located at the tube inlet and outlet, and a twisted section located between the tube inlet and outlet. The twisted section is situated between the two straight sections, and its cross-section is elliptical, with the ratio of its major axis to its minor axis being 1.2-1.3. This design enhances the turbulence within the swirl heat exchanger tube 9 without significantly increasing flow resistance, thereby improving heat exchange efficiency while controlling fluid pressure drop and meeting the heat exchange requirements of high-vacuum heat pump distillation systems.

[0037] like Figure 3 As shown, three swirl vanes 11 are provided, evenly distributed circumferentially on the inner wall of the straight section at the pipe inlet. The major axis of the tortuous section is 2a, and its minor axis is 2b. Figure 3 As shown, the ratio of the major axis to the minor axis of the elliptical structure is 1.25.

[0038] The heat exchanger body is inclined downwards along the material flow direction inside the swirl heat exchange tube 9, with an inclination angle of 1°-5°. When the material inside the heat exchange tube is prone to crystallization, an inclined heat exchanger is preferred; a slightly downward-inclined heat exchanger can eliminate the static liquid column and facilitate the return of the gas-liquid two-phase flow to the tower bottom by gravity after leaving the heat exchanger; the inclined heat exchange tube body not only helps the material return to the tower bottom quickly, but also helps the material inside the heat exchange tube to be quickly drained when the machine is shut down.

[0039] The diameter of the straight section of the swirl heat exchanger tube 9 is 15mm, 19mm, or 25mm. Using a small-diameter tube, the swirl heat exchanger tube 9 can be selected with a straight section diameter of φ15, φ19, or φ25mm. The smaller diameter swirl heat exchanger tube 9 better highlights the strengthening effect of the swirl vanes 11 and the micro-twisted structure, achieving more thorough radial mixing between the enhanced laminar flow and the turbulent main body at the tube center, thus achieving a better heat transfer enhancement effect.

[0040] The material inlet 1 is located at the bottom of the upper tube box 5, and the upper end of the guide plate 8 is connected to the upper inner wall of the upper tube box 5. Under the guiding action of the guide plate 8, the material entering the upper tube box 5 is more evenly distributed into each swirl heat exchange tube 9, ensuring that all swirl heat exchange tubes 9 can fully participate in heat exchange.

[0041] The cylinder body is also equipped with multiple baffles 10.

[0042] The material to be heated in the reboiler enters the upper tube box 5 through material inlet 1. The material fluid is guided and evenly distributed by guide plate 8 into the swirl heat exchange tube 9. Heat source steam enters the heat exchange shell 6 through gas phase inlet 3, and under the action of baffle plate 10, it sweeps laterally across the swirl heat exchange tube 9, transferring heat to the material inside the swirl heat exchange tube 9 while condensing, and finally leaves the heat exchanger through condensate outlet 4. After being heated, the material inside the swirl heat exchange tube 9 partially vaporizes, and the gas and liquid phases flow axially along the swirl heat exchange tube 9 to the lower tube box 7, leaving the heat exchanger through material outlet 2 and entering the reboiler of the distillation column of the high-vacuum heat pump distillation system. The inner wall of the swirl heat exchange tube 9 inlet has swirl vanes 11. The swirl vanes 11 are evenly distributed circumferentially and are welded or integrally formed on the inner wall of the swirl heat exchange tube 9. When the fluid flows axially, it is forced to move relative to the surface, forming a strong secondary flow, which greatly enhances the mass and energy exchange between the fluid core region and the near-wall region, reduces the heat transfer resistance of the laminar layer, and achieves enhanced heat transfer. Figure 3 This is a cross-sectional view of the heat exchange tube. 3-6 swirl vanes 11 are evenly distributed. The micro-twisted structure of the swirl heat exchange tube 9 causes the fluid flow direction inside the tube to change periodically without significantly increasing the pressure drop of the fluid.

[0043] Example 2 like Figure 4As shown, when the material inside the swirl heat exchange tube 9 of the transverse swirl heat exchanger is a conventional material, i.e., a material that is not easily crystallized, a transversely arranged heat exchanger can also be selected. The heat exchanger body is arranged transversely, and the axis of the heat exchanger body is parallel to the horizontal plane. The transversely arranged heat exchanger can eliminate the static liquid column formed by the vertical swirl heat exchange tube 9. The material pressure at all points inside the swirl heat exchange tube 9 is basically equal to the pressure in the reboiler of the high vacuum heat pump distillation system, and the material temperature is consistent with the boiling point temperature of the reboiler.

[0044] Application of the transverse swirl heat exchanger in a high-vacuum heat pump distillation system. A pharmaceutical company recovers methanol solvent from waste liquid using a distillation column, employing a closed-loop heat pump distillation system with R134a as the working fluid. The column top pressure is 13 kPaA, and the top temperature is 20.17℃. The working fluid absorbs heat in the top condenser evaporator, producing saturated vapor at 14℃. The column bottom pressure is 15 kPaA, the bottom temperature is 54.4℃, and the bottom heat load is 1520 kW. The electricity price for this project is 0.7 yuan / kW·h.

[0045] Comparing the economics of conventional vertical shell-and-tube heat exchangers and the transverse swirl heat exchanger of this invention, the following results are obtained: Table 1 Economic Comparison

[0046] By using the transverse swirl heat exchanger of the present invention, the condensing temperature is reduced by 6.0℃, the heat pump power consumption is reduced by 74kW per hour, and the annual electricity cost is reduced by RMB 414,400, which accounts for approximately 18.5% of the electricity cost.

[0047] Specifically, the reboiler in the high-vacuum heat pump distillation system uses a conventional vertical shell-and-tube heat exchanger. A 50 cm column of static liquid exists in the tube side, with an actual pressure of approximately 19 kPaA in the middle section, corresponding to a bubble point temperature of 60.4℃. To ensure heat transfer, 71℃ working fluid steam with a pressure of approximately 2165 kPaA is selected for heating.

[0048] The reboiler of the tower uses the transverse swirl heat exchanger of this invention, which can eliminate the static liquid column in the tube side. The material temperature in the heat exchanger is the same as the material temperature in the tower bottom. Considering the same heat exchange temperature difference, saturated steam at 65°C and a pressure of about 1890 kPaA is selected, which has lower requirements for the compressor parameters of the heat pump system and lower power consumption.

[0049] Further comparisons were made between the micro-twisted swirl heat exchanger tube 9 and the vertical smooth tube used in this invention in terms of heat transfer performance. Specifically, a shell-and-tube heat exchanger was selected, and the heat transfer performance of the swirl heat exchanger tube 9 and the vertical smooth tube in the reboiler was compared. The inner tube of the shell-and-tube heat exchanger A was selected as... Figure 2The φ25 swirl heat exchanger tube 9 shown has 4 swirl vanes 11. The inner tube of the shell-and-tube heat exchanger B is a standard φ38 vertical bare tube. A falling film distributor is installed at the top of the inner tube to ensure tangential liquid flow towards the vertical bare tube and uniform film distribution. 60℃ hot water is introduced into the inner tube inlet of the shell-and-tube heat exchanger, and the inner tube outlet is connected to a receiving tank. A condenser is connected to the gas phase port at the top of the receiving tank to condense the gas phase. A vacuum pump is connected to the condenser's gas phase port to maintain a vacuum environment in the system. The outer tube of the shell-and-tube heat exchanger can be a DN80 fitting, and 85℃ hot water is introduced. The hot water outlet temperature is maintained at 80℃ by adjusting the opening of the hot water pipeline valve. After one hour of stable operation, the water flow rate into the inner tube, the water flow rate into the receiving tank, the condensate flow rate in the condenser, and the temperature at various locations are measured to compare the heat transfer effects of the two systems. The following results are obtained: Table 2 Comparison of heat transfer effects

[0050] Experimental data show that the swirl heat exchanger tube 9 operates at a low vaporization rate of 3.8%, while the vertical bare tube achieves a vaporization rate of 29.3%, which aligns with their different design philosophies and operating conditions. Furthermore, the circulation rate of the swirl heat exchanger tube 9 (135 kg / h) is 4.5 times that of the vertical bare tube (30 kg / h), realizing the "large circulation rate, high flow rate" operating mode emphasized in this invention.

[0051] Based on the above results, it can be concluded that under this operating condition, the overall heat transfer coefficient of the swirl heat exchanger tube 9 is increased by approximately 18.46% compared to the vertical smooth tube. Since the shell-side heat transfer coefficient is relatively high, the tube-side heat transfer resistance is often dominant. Therefore, the increase in the overall heat transfer coefficient can be regarded as an approximately proportional increase in the tube-side heat transfer coefficient. This increase verifies the effectiveness of the intensification mechanism of the swirl vanes 11 and the swirl heat exchanger tube 9 in disrupting the laminar layer and enhancing turbulence, and also confirms the superiority of the "small diameter, high flow velocity" design.

[0052] This invention employs small-diameter heat exchange tubes and operates under low vaporization rate and high circulation volume conditions, with the vaporization rate controlled between 2% and 5%. Addressing the problems of high heat source requirements, low heat transfer efficiency, and easy wall dryness in existing vertical reboilers due to the stagnant liquid column, the heat exchanger is arranged horizontally or slightly downwardly to eliminate the stagnant liquid column and reduce the required heat source specifications. The swirl heat exchange tube 9 has swirl vanes 11 on its inlet inner wall and adopts a slightly twisted tube shape. Without significantly increasing the fluid pressure drop, this allows the fluid inside the tube to reach a turbulent state under low flow rate conditions, enhancing heat transfer, further improving the heat transfer coefficient, and providing self-cleaning capability. The described transverse swirl heat exchanger is suitable as a reboiler in a high-vacuum heat pump distillation system, significantly reducing compressor power consumption, improving the heat transfer coefficient, and extending the operating cycle.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A transverse swirl heat exchanger for a high-vacuum heat pump distillation system, comprising a heat exchanger body, the heat exchanger body including a heat exchange shell (6), the heat exchange shell (6) being provided with a material inlet (1), a material outlet (2), a gas phase inlet (3), and a condensate outlet (4), characterized in that, The heat exchanger body is horizontally arranged. The heat exchange shell (6) includes a cylinder, an upper tube box (5) located at one end of the cylinder, and a lower tube box (7) located at the other end of the cylinder. The cylinder is provided with a plurality of parallel swirling heat exchange tubes (9). The diameter of the swirling heat exchange tubes (9) is less than or equal to 25 mm. The material inlet (1) is located on the upper tube box (5). The swirling heat exchange tube (9) is provided with swirling vanes (11) at the tube inlet. The upper tube box (5) is provided with a guide plate (8). The guide plate (8) is inclined so that the material entering through the material inlet (1) can be more evenly distributed into the swirl heat exchange tube (9) under the guiding effect of the guide plate (8).

2. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to claim 1, characterized in that, The angle between the guide plate (8) and the axis of the heat exchanger body is 30°-60°, and the length of the guide plate (8) is 60%-90% of the inner diameter of the upper tube box (5).

3. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to claim 1, characterized in that, The swirl vanes (11) are provided in multiples, and the multiple swirl vanes (11) are uniformly arranged circumferentially on the inner wall of the tube inlet of the swirl heat exchange tube (9).

4. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to claim 3, characterized in that, The swirl vane (11) is positioned 50mm-150mm away from the inlet of the swirl heat exchange tube (9).

5. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to claim 1, characterized in that, The swirl heat exchanger tube (9) is a twisted tube.

6. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to claim 5, characterized in that, The swirling heat exchange tube (9) includes a straight section located at the tube inlet and the tube outlet, and a twisted section located between the tube inlet and the tube outlet. The twisted section is located between the two straight sections. The cross-section of the twisted section of the swirling heat exchange tube (9) is an elliptical structure, and the ratio of the length of the major axis to the length of the minor axis of the elliptical structure is 1.2-1.

3.

7. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to any one of claims 1-6, characterized in that, The heat exchanger body is arranged horizontally, and the axis of the heat exchanger body is parallel to the horizontal plane.

8. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to any one of claims 1-6, characterized in that, The heat exchanger body is inclined downward along the material flow direction inside the swirling heat exchange tube (9), and the downward inclination angle of the heat exchanger body is 1°-5°.

9. The transverse cyclone heat exchanger for a high-vacuum heat pump distillation system according to any one of claims 1-6, characterized in that, The diameter of the straight section of the swirl heat exchanger tube (9) is 15mm, 19mm or 25mm.

10. The transverse swirl heat exchanger for a high-vacuum heat pump distillation system according to any one of claims 1-6, characterized in that, The material inlet (1) is located at the bottom of the upper tube box (5), and the upper end of the guide plate (8) is connected to the upper side of the inner wall of the upper tube box (5).

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