A heat shock flash evaporation loop lift heat exchanger

Abstract

The present application relates to a kind of hot exciting flash evaporation loop lift heat exchanger, including upper head, lower head, cylinder, several heat exchange tubes, the upper end surface of cylinder and the upper head form cavity I between, the lower end surface of cylinder and the lower head form cavity II between, cavity I, cavity II and the inner cavity of cylinder are not communicated with each other between, heat exchange tube is fixed in the inside of cylinder by tube sheet, the upper end of heat exchange tube is placed in cavity I and is communicated with cavity I, lower end and cavity II are communicated, cylinder includes lift section cylinder and hot exciting section cylinder, heat exchange tube includes lift section heat exchange tube and hot exciting section heat exchange tube, lift section heat exchange tube and hot exciting section heat exchange tube are communicated by throttling component between, the inner diameter of throttling component is less than the inner diameter of hot exciting section heat exchange tube.The heat exchanger of the present application is provided with a kind of hot exciting flash evaporation loop lift, will hot exciting pressurization energy storage, throttling flash evaporation kinetic energy release, loop lift heat exchange and vapor-liquid separation function integration in same equipment, solve the problem of traditional lift section heat exchanger dependence big temperature difference.

Description

Technical Field

[0001] This invention relates to the field of rising film heat exchange equipment technology, and in particular to a thermally stimulated flash evaporation circulating rising film heat exchanger. Background Technology

[0002] Rising film heat exchange is a highly efficient in-tube phase change heat transfer technology. Its principle involves using high-speed steam generated by material evaporation to drive the liquid along the inner wall of the heat exchange tube, forming a uniform, ultra-thin liquid film that rises upwards. By reducing the thickness of the liquid film, the thermal resistance is lowered, thereby enhancing heat transfer. Rising film heat exchange is widely used in the processing of low-viscosity, heat-sensitive, and easily foaming materials due to its short material residence time, high heat transfer efficiency, and compact equipment structure. A conventional rising film heat exchange process sequentially goes through five stages: single-phase liquid flow, bubbly flow, slug flow, annular flow, and mist flow. The annular flow stage is the core stage for achieving high-efficiency heat transfer; in this stage, the vapor phase is a continuous phase, and the liquid phase is an ultra-thin liquid film rising along the wall, reaching peak heat transfer efficiency.

[0003] To achieve sufficient driving force for rising film heat exchangers, conventional rising film heat exchangers require high heat flux density input under a large heat transfer temperature difference. This forces the liquid in the inlet section of the heat exchanger to vaporize rapidly, gradually increasing the vapor velocity inside the tubes and driving the flow pattern from single-phase liquid flow, bubbly flow, and slug flow to annular flow. The heat transfer temperature difference requirement for conventional rising film heat exchangers is generally not lower than 20°C. However, in energy-saving processes such as MVR and heat pumps, the heat transfer temperature difference provided by the energy-saving system is generally not higher than 10°C due to the increased boiling point of the liquid and the limitation of the compressor's ultimate pressure ratio. When the heat exchanger operates under this narrow temperature difference condition, problems such as excessively long preheating section, insufficient vaporization rate, difficulty in liquid film formation, and the flow pattern inside the tubes remaining in bubbly or slug flow, making it difficult to generate annular flow, will occur, and the heat exchanger will be unable to achieve effective rising film heat exchange operation. Summary of the Invention

[0004] The present invention aims to provide a thermally stimulated flash evaporation circulating rising film heat exchanger to overcome the shortcomings of the prior art. The technical problem to be solved by the present invention is achieved through the following technical solution.

[0005] A thermally activated flash circulating rising film heat exchanger includes an upper head, a lower head, a cylindrical body, and a plurality of heat exchange tubes. The upper head and the lower head are located at the upper and lower ends of the cylindrical body, respectively. A cavity I is formed between the upper end face of the cylindrical body and the upper head, and a cavity II is formed between the lower end face of the cylindrical body and the lower head. Cavities I and II are not interconnected with the inner cavity of the cylindrical body. The heat exchange tubes are fixed inside the cylindrical body by a tube sheet, and the upper end of each heat exchange tube is placed inside cavity I and connected to the inner cavity of the cylindrical body. The lower port is connected to the cavity II. The cylinder includes a rising film section cylinder and a heat-quenching section cylinder arranged adjacent to each other at the top and bottom. The heat exchange tube includes a rising film section heat exchange tube and a heat-quenching section heat exchange tube that are matched with each other. The length of the rising film section heat exchange tube is matched with the rising film section cylinder, and the length of the heat-quenching section heat exchange tube is matched with the heat-quenching section cylinder. The rising film section heat exchange tube and the heat-quenching section heat exchange tube are connected by a throttling device. The inner diameter of the throttling device is smaller than the inner diameter of the heat-quenching section heat exchange tube.

[0006] Preferably, the tube sheet includes an upper tube sheet and a lower tube sheet, the upper end cap is sealed to the upper end of the cylinder through the upper tube sheet, and the lower end of the cylinder is sealed to the lower end cap through the lower tube sheet; the heat exchange tube is fixed to the cylinder through the upper tube sheet and the lower tube sheet.

[0007] Preferably, the tube sheet further includes a middle tube sheet, and the lower part of the rising film section heat exchange tube is fixed to the rising film section cylinder through the middle tube sheet.

[0008] Preferably, the upper end of the upper head is provided with a secondary steam outlet and the lower side wall is provided with a discharge port, and the bottom end of the lower head is provided with a feed port.

[0009] Preferably, an anti-impact plate is provided below the secondary steam outlet.

[0010] Preferably, a demister mesh is installed inside the pipe of the secondary steam outlet.

[0011] Preferably, the upper sidewall of the rising film section cylinder is provided with a low-pressure steam inlet and the lower sidewall is provided with a low-pressure condensate outlet.

[0012] Preferably, the upper side wall of the heat-induced section cylinder is provided with a high-pressure steam inlet, and the lower side wall is provided with a high-pressure condensate outlet.

[0013] Preferably, the cylinder is provided with baffles.

[0014] Preferably, the throttling component is a reducer, an orifice plate, or a reducer internal component.

[0015] The present invention provides a thermally stimulated flash evaporation circulating rising film heat exchanger, which has the following beneficial effects: 1) This invention directly provides rising film kinetic energy through in-tube throttling flash evaporation, eliminating the need for a large temperature difference heat source above 20°C and enabling stable operation within a narrow temperature difference range of 5-10°C. The in-tube flow pattern directly skips inefficient stages such as bubbly and slug flows, rapidly forming a highly efficient annular flow, improving heat transfer efficiency by more than 30% compared to traditional rising film heat exchangers. This effectively solves the industry problem of ineffective rising film heat exchange in narrow temperature difference energy-saving processes such as MVR and heat pumps.

[0016] 2) The throttling component of the present invention is located between the heat exchange tube of the heat-quenching section and the heat exchange tube of the rising film section. The liquid is throttled and flashed inside the heat exchange tube, thereby avoiding the problem of uneven vapor distribution in the heat exchange tube caused by the external placement of the throttling component. This ensures that a uniform and stable annular liquid film can be formed in each heat exchange tube, greatly improving the stability and reliability of the equipment operation.

[0017] 3) This invention integrates four major functions—heat blasting, throttling flash evaporation, rising film heat exchange, and vapor-liquid separation—into a single heat exchanger, simplifying the structure of the heat blasting, flash evaporation, and rising film systems and reducing the installation and maintenance costs of external components. The rising film heat exchange process can utilize low-grade industrial waste heat, making it more suitable for energy-saving process systems such as MVR and heat pumps. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of one embodiment of the heat exchange tube in this invention; Figure 3 This is a schematic diagram of the structure of one embodiment of the throttling component in this invention; Figure 4 This is a schematic diagram of the annular rising film flow pattern inside the heat exchange tube in one embodiment of the present invention; Figure 5 This is a schematic diagram of another embodiment of the heat exchange tube in this invention; Figure 6 This is a schematic diagram of another embodiment of the heat exchange tube in this invention; The reference numerals in the attached figures are as follows: 1. Upper head, 2. Discharge port, 3. Upper tube sheet, 4. Rising film section cylinder, 5. Heat exchange tube, 51. Rising film section heat exchange tube, 52. Throttling component, 53. Heat exchange tube of the heat quench section, 6. Baffle plate, 7. Low-pressure condensate outlet, 8. Middle tube sheet, 9. High-pressure condensate outlet, 10. Lower head, 11. Feed port, 12. Lower tube sheet, 13. Heat quench section cylinder, 14. High-pressure steam inlet, 15. Low-pressure steam inlet, 16. Anti-impact plate, 17. Defogging mesh, 18. Secondary steam outlet. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Example 1: Reference Figures 1 to 6 As shown, a thermally stimulated flash evaporation circulating rising film heat exchanger is improved in that it includes an upper end cap 1, a lower end cap 10, a cylinder, and several heat exchange tubes 5. The upper end cap 1 and the lower end cap 10 are located at the upper and lower ends of the cylinder, respectively. A cavity I is formed between the upper end face of the cylinder and the upper end cap 1, and a cavity II is formed between the lower end face of the cylinder and the lower end cap 10. Cavities I and II are not interconnected with the inner cavity of the cylinder. The heat exchange tubes 5 are fixed inside the cylinder by a tube sheet, and the upper end of the heat exchange tubes 5 is placed inside cavity I and connected to the inner cavity. The upper port is connected to the lower port and the lower port is connected to the cavity II. The cylinder includes a rising film section cylinder 4 and a heat-quenching section cylinder 13 arranged adjacent to each other. The heat exchange tube 5 includes a rising film section heat exchange tube 51 and a heat-quenching section heat exchange tube 53 that are matched with each other. The length of the rising film section heat exchange tube 51 is matched with the rising film section cylinder 4, and the length of the heat-quenching section heat exchange tube 53 is matched with the heat-quenching section cylinder 13. The rising film section heat exchange tube 51 and the heat-quenching section heat exchange tube 53 are connected by a throttling component 52. The inner diameter of the throttling component 52 is smaller than the inner diameter of the heat-quenching section heat exchange tube 53.

[0021] The working process of a thermal flash evaporation film heat exchanger provided in this embodiment is as follows: Thermal surge and pressurization energy storage stage: After being pressurized, the liquid enters the lower head 10 from the bottom inlet 11, and then enters the heat exchange tube 5. In the heat exchange tube 53 of the thermal surge section, the liquid is heated to a high-pressure subcooled or saturated state by the high-temperature live steam in the thermal surge section cylinder 13, thus completing the storage of high-temperature heat source heat energy into the internal energy of the liquid.

[0022] Throttling flash kinetic energy release stage: The high-pressure and high-temperature liquid in the heat exchange tube 53 of the heat shock section flows through the throttling component 52, and is reduced to the evaporation pressure of the rising film heat exchange, which triggers the isenthalpic flash evaporation of the liquid. The secondary steam generated by the flash evaporation causes the volume of the vapor-liquid two-phase liquid after throttling to expand rapidly, thereby forming a high-kinetic-energy vapor-liquid two-phase flow.

[0023] Kinetic energy driven rising film heat exchange stage: High kinetic energy vapor-liquid two-phase flow enters the rising film section heat exchange tube 51. Driven by the kinetic energy of throttling flash expansion, the liquid forms a uniform annular liquid film along the heat exchange tube wall. The heat source of the rising film section heat exchange tube 51 is supplied by low-pressure steam in the rising film section cylinder 4. The temperature of this low-pressure steam only needs to be 5~10℃ higher than the evaporation temperature of the liquid.

[0024] Vapor-liquid separation discharge stage: The vapor-liquid mixture continues to rise and completes vapor-liquid separation within the upper head 1. Secondary steam is discharged from the top of the upper head 1, and the concentrated liquid at the upper outlet of the heat exchange tube 5 is discharged through the discharge port 2 of the upper head 1.

[0025] In this embodiment, the longitudinal section of the upper head 1 is semi-elliptical, and a straight section is provided at the bottom of the upper head 1. The straight section serves as the space for gravity settling and vapor-liquid separation in the rising film heat exchanger; the longitudinal section of the lower head 10 is semi-elliptical or conical.

[0026] Furthermore, the tube sheet includes an upper tube sheet 3 and a lower tube sheet 12. The upper end cap 1 is sealed to the upper end of the cylinder through the upper tube sheet 3, and the lower end of the cylinder is sealed to the lower end cap through the lower tube sheet 12. The heat exchange tube 5 is fixed to the cylinder through the upper tube sheet 3 and the lower tube sheet 12.

[0027] Furthermore, the tube sheet also includes a middle tube sheet 8, and the lower part of the rising film section heat exchange tube 51 is fixed to the rising film section cylinder 4 through the middle tube sheet 8.

[0028] Furthermore, the upper end of the upper head 1 is provided with a secondary steam outlet 18 and the lower end side wall is provided with a discharge port 2, and the bottom end of the lower head 10 is provided with a feed port 11.

[0029] In this embodiment, the diameters of the rising film section cylinder 4 and the heat-quench section cylinder 13 are equal, and the height ratio of the rising film section cylinder 4 to the heat-quench section cylinder 13 is 2:1 to 15:1. The upper end of the rising film section cylinder 4 is welded to the upper tube sheet 3, and the lower end is welded to the middle tube sheet 8. The upper end of the heat-quench section cylinder 13 is welded to the middle tube sheet 8, and the lower end is welded to the lower tube sheet 12. The upper end cap 1 is sealed to the upper tube sheet 3 through a flange, and the lower end cap 10 is sealed to the lower tube sheet 12 through a flange.

[0030] Furthermore, the upper side wall of the rising film section cylinder 4 is provided with a low-pressure steam inlet 15, and the lower side wall is provided with a low-pressure condensate outlet 7. A low-grade heat source with a temperature only 5~10℃ higher than the evaporation temperature of the feed liquid is introduced into the rising film section cylinder 4 to maintain the heat of phase change in the rising film.

[0031] Furthermore, the upper side wall of the heat-stimulated section cylinder 13 is provided with a high-pressure steam inlet 14, and the lower side wall is provided with a high-pressure condensate outlet 9. High-temperature live steam is introduced into the heat-stimulated section cylinder 13 to perform thermal surge pressure storage on the feed liquid entering the heat exchange tube 53.

[0032] In this embodiment, the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53 have the same diameter specifications. The length-to-diameter ratio of the rising film section heat exchange tube 51 is 100~150, and the length-to-diameter ratio of the heat quench section heat exchange tube 53 is 10~50. The heat exchange tubes 5 are installed vertically, with an overall verticality tolerance within 5mm / m. The upper part of the rising film section heat exchange tube 51 is fixedly connected to the upper tube sheet 3 and extends out of the upper tube sheet 3. The upper end of the rising film section heat exchange tube 51 is 100~200mm higher than the upper tube sheet 3, thereby enabling the upper tube sheet 3 to collect and discharge the concentrated liquid at the outlet of the heat exchange tube 5, preventing unevaporated liquid from flowing back into the heat exchange tube 5 and affecting the rising film morphology inside the heat exchange tube 5. The lower end of the rising film section heat exchange tube 51 is fixedly connected to the middle tube sheet 8, and the lower end of the heat quench section heat exchange tube 53 is fixedly connected to the lower tube sheet 12.

[0033] Furthermore, an anti-impact plate 16 is provided below the secondary steam outlet 18.

[0034] Furthermore, a demister mesh 17 is installed inside the pipe of the secondary steam outlet 18.

[0035] Furthermore, a baffle plate 6 is provided inside the cylinder, which is an arc-shaped baffle plate or a spiral baffle plate.

[0036] Furthermore, the throttling component 52 is a variable diameter pipe, orifice plate, or reduced diameter pipe internal component. The throttling component 52 is embedded between the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53, or built into the outlet section of the heat quench section heat exchange tube 53; its function is to throttle and reduce the pressure of the high-pressure saturated liquid after heat quench heating, forcing the heat quenched liquid to undergo throttling isenthalpic flash evaporation, converting the high-temperature internal energy stored in the heat quench heating section into the expansion kinetic energy of the vapor-liquid two-phase after throttling, and the flash steam directly pushes the liquid in the rising film heat exchange tube 51 to quickly form a circulating flow state.

[0037] Example 2: Based on Example 1, this example provides a heat exchanger suitable for the concentration process of glucose solution in the food industry, with a feed rate of 5t / h, an initial concentration of 20% and a target concentration of 60%.

[0038] Reference Figure 1As shown, this embodiment of a thermal flash evaporation circulating rising film heat exchanger has an overall vertical double-shell tube structure. The end caps include an upper end cap 1 and a lower end cap 10. The diameter of both the upper and lower end caps is 1000mm. The upper end cap adopts an elliptical end cap structure, and a straight cylindrical section with a height of 300mm is provided at the bottom of the upper end cap, which serves as a gravity settling vapor-liquid separation space for the rising film heat exchanger. The top of the upper end cap 1 is provided with a secondary steam outlet 18, and the bottom side wall is provided with a discharge port 2. An anti-impact plate 16 is provided below the secondary steam outlet position inside the upper end cap, and a demister mesh 17 is built into the secondary steam outlet pipe. The lower end cap adopts an elliptical end cap, and the bottom of the lower end cap is provided with a feed inlet 11.

[0039] The tube sheet includes an upper tube sheet 3, a middle tube sheet 8, and a lower tube sheet 12, and all tube sheets have heat exchange tube openings with the same layout.

[0040] The cylinder consists of two sections: an upper rising film section 4 and a lower heat-quenching section 13. Both the rising film section 4 and the heat-quenching section 13 have a diameter of 1000mm, a height of 3000mm for the rising film section 4, and a height of 500mm for the heat-quenching section 13. The upper end of the rising film section 4 is welded to the upper tube sheet 3, and the lower end is welded to the middle tube sheet 8. The upper end of the heat-quenching section 13 is welded to the middle tube sheet 8, and the lower end is welded to the lower tube sheet 12. The upper end cap 10 is flanged to the upper tube sheet 3, and the lower end cap 10 is flanged to the lower tube sheet 12. The upper side wall of the rising film section 4 has a low-pressure steam inlet 15, and the lower side wall has a low-pressure condensate outlet 7. The upper side wall of the heat-quenching section 13 has a high-pressure steam inlet 14, and the lower side wall has a high-pressure condensate outlet 9.

[0041] Reference Figure 2 As shown, the heat exchange tube 5 includes an upper rising film section heat exchange tube 51 and a lower heat quench section heat exchange tube 53, with a throttling device 52 between the two sections. Both the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53 are made of 316L steel with a diameter of 25mm and a wall thickness of 1mm. The rising film section heat exchange tube 51 is 3200mm long, and the heat quench section heat exchange tube 53 is 400mm long. The upper end of the rising film section heat exchange tube 51 extends through the upper tube sheet 3. The upper end face of the tube opening is 200mm higher than the upper end face of the upper tube sheet 3, thereby enabling the upper tube sheet 3 to collect and discharge the concentrated liquid at the outlet of the heat exchange tube 5, and preventing the unevaporated liquid from flowing back into the heat exchange tube and affecting the liquid film morphology inside the heat exchange tube; the lower end of the rising film section heat exchange tube 51 is connected and fixed to the middle tube sheet 8; the lower section of the heat quench section heat exchange tube 53 is welded and fixed to the lower tube sheet; both the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53 are equipped with baffles 6, and the baffles are bow-shaped baffles.

[0042] The working process of this embodiment is as follows: The glucose solution enters the heat exchange tube 5 through the bottom inlet 11 of the heat exchanger. Inside the heating tube 53 of the heat quench section, it is heated to 100°C by the 120°C high-temperature live steam inside the heat quench section cylinder 13, with a solution pressure of 100 kPa(a), thus completing the storage of high-temperature thermal energy into the internal energy of the liquid. Afterwards, the 100°C liquid flows through the throttling device 52, reducing its pressure to approximately 47 kPa(a). The high-temperature liquid undergoes isenthalpic flash evaporation, and the volume expansion of the flash steam results in a higher kinetic energy in the vapor-liquid mixture after throttling. (Refer to...) Figure 4 As shown, a high-kinetic-energy vapor-liquid two-phase flow enters the rising film heat exchanger tube 51. Driven by the kinetic energy of vapor phase expansion, the liquid is dragged by flash steam and rapidly forms an annular liquid film along the tube wall. The evaporation temperature of the liquid inside the rising film heat exchanger tube 51 is 85℃. Low-pressure steam at 90℃ is introduced into the rising film section cylinder 4 as the heating source for the rising film heat exchanger tube 51. The vapor-liquid mixture at the outlet of the rising film section heat exchanger tube 51 undergoes preliminary gravity sedimentation separation at the upper end cap 1, and then is defoamed by the demister screen 17 before being discharged through the secondary steam outlet 18. The concentrated liquid at the outlet of the heat exchanger tube 5 is collected and discharged through the discharge port 2.

[0043] Example 3: Based on Example 2, referring to Figure 3 As shown, the throttling component 52 in this embodiment adopts a reducing pipe with a total length of 100mm. The two ends are reducing joints, and the middle part is a thin pipe with a diameter of 10mm and a length of 60mm. The reducing joints at both ends are 25mm / 10mm. The throttling component 52 is welded to the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53 respectively.

[0044] Example 4: Based on Embodiment 2, the throttling component 52 in this embodiment adopts an orifice plate. (Refer to...) Figure 5 As shown, the orifice plate has an outer diameter of 25mm, a thickness of 10mm, and an inner diameter of 5mm. The orifice plate is welded to the rising film section heat exchange tube 51 and the heat quench section heat exchange tube 53, respectively.

[0045] Example 5: Based on Example 2, the throttling component 52 in this example uses a reduced-diameter pipe internal. (Refer to...) Figure 6 As shown, the reduced-diameter tube inner part is a cylindrical structure with a total length of 100mm and an outer diameter of 23mm. The middle part is a through hole with a diameter of 10mm and a length of 60mm. There are bell mouths with a length of 20mm on both sides. The bell mouth specifications are 23mm / 10mm. The reduced-diameter tube inner part is placed inside the upper outlet of the heat exchange tube 53 in the heat ignition section. The heat exchange tube 53 in the heat ignition section and the heat exchange tube 51 in the rising film section are connected by butt welding.

[0046] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0047] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments described in this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0049] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0050] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, such as rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0051] In the detailed description above, reference has been made to the accompanying drawings, which form part of this document. In the drawings, similar symbols typically identify similar parts unless the context otherwise indicates otherwise. The illustrated embodiments described in the detailed specification, drawings, and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thermally activated flash circulating rising film heat exchanger, characterized in that: The device includes an upper end cap (1), a lower end cap (10), a cylindrical body, and several heat exchange tubes (5). The upper end cap (1) and the lower end cap (10) are located at the upper and lower ends of the cylindrical body, respectively. A cavity I is formed between the upper end face of the cylindrical body and the upper end cap (1), and a cavity II is formed between the lower end face of the cylindrical body and the lower end cap (10). The cavities I and II are not connected to the inner cavity of the cylindrical body. The heat exchange tubes (5) are fixed inside the cylindrical body by a tube sheet. The upper end of the heat exchange tube (5) is placed inside the cavity I and connected to the cavity I, and the lower end is connected to the cavity II. The cylinder body includes a rising film section cylinder body (4) and a heat-quenching section cylinder body (13) arranged adjacent to each other. The heat exchange tube (5) includes a rising film section heat exchange tube (51) and a heat-quenching section heat exchange tube (53) that are matched with each other. The length of the rising film section heat exchange tube (51) is matched with the rising film section cylinder body (4), and the length of the heat-quenching section heat exchange tube (53) is matched with the heat-quenching section cylinder body (13). The rising film section heat exchange tube (51) and the heat-quenching section heat exchange tube (53) are connected by a throttling component (52). The inner diameter of the throttling component (52) is smaller than the inner diameter of the heat-quenching section heat exchange tube (53).

2. The thermal flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The tube sheet includes an upper tube sheet (3) and a lower tube sheet (12). The upper end cap (1) is sealed to the upper end of the cylinder through the upper tube sheet (3), and the lower end of the cylinder is sealed to the lower end cap through the lower tube sheet (12). The heat exchange tube (5) is fixed to the cylinder through the upper tube sheet (3) and the lower tube sheet (12).

3. A thermal flash evaporation circulating rising film heat exchanger according to claim 2, characterized in that: The tube sheet also includes a middle tube sheet (8), and the lower part of the rising film section heat exchange tube (51) is fixed to the rising film section cylinder (4) through the middle tube sheet (8).

4. A thermal flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The upper end of the upper head (1) is provided with a secondary steam outlet (18) and the lower end side wall is provided with a discharge port (2). The bottom end of the lower head (10) is provided with a feed inlet (11).

5. A thermal flash evaporation circulating rising film heat exchanger according to claim 4, characterized in that: An anti-impact plate (16) is provided below the secondary steam outlet (18).

6. A thermal flash evaporation circulating rising film heat exchanger according to claim 4, characterized in that: The secondary steam outlet (18) is equipped with a demister mesh (17) inside the pipe.

7. A thermally stimulated flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The upper side wall of the rising film section cylinder (4) is provided with a low-pressure steam inlet (15), and the lower side wall is provided with a low-pressure condensate outlet (7).

8. A thermal flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The upper side wall of the heat-induced section cylinder (13) is provided with a high-pressure steam inlet (14), and the lower side wall is provided with a high-pressure condensate outlet (9).

9. A thermal flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The cylinder is equipped with baffles (6).

10. A thermal flash evaporation circulating rising film heat exchanger according to claim 1, characterized in that: The throttling component (52) is a reducer, orifice plate, or internal component of a narrow-diameter pipe.

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