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CN-122015557-A - Boiling heat exchange device suitable for long pipeline and application method thereof

CN122015557ACN 122015557 ACN122015557 ACN 122015557ACN-122015557-A

Abstract

The invention discloses a boiling heat exchange device suitable for a long pipeline and a use method thereof, and belongs to the technical field of boiling heat exchange equipment. The invention comprises an outer sleeve and a plurality of limiting pipelines which are annularly arranged along the inner wall of the outer sleeve, wherein the inner cavity of the limiting pipeline is divided into a plurality of mutually communicated limiting spaces, a liquid storage part is arranged in the limiting spaces, the liquid storage part comprises a shell and a hollow cavity surrounded by the shell, a plurality of micropores are formed in the shell, and the liquid storage part sucks liquid through the micropores on the surface and stores the liquid in the hollow cavity. The liquid storage part moves in the limiting space under the pushing of the liquid phase or the gas phase, then liquid stored in the hollow cavity is separated from the liquid storage part through the micropores, the separated liquid part is used for wetting the pipe wall, and the separated liquid part is transferred to the next limiting space, so that the along-path sectional liquid supplementing and rewetting are realized, the heat exchange capacity attenuation of a high-dryness section is slowed down, and the heat exchange stability is improved.

Inventors

  • WANG DONGDONG
  • CAO GUOQING
  • CHU HUAQIANG
  • ZHU XIAOYA
  • DING SHILEI
  • WANG TINGHUI

Assignees

  • 安徽工业大学

Dates

Publication Date
20260512
Application Date
20260323

Claims (10)

  1. 1. The boiling heat exchange device suitable for the long pipeline comprises an outer sleeve (100) and is characterized in that a plurality of limiting pipelines (400) extending along the axial direction of the outer sleeve (100) are annularly arranged on the inner wall of the outer sleeve (100); The whole limiting pipeline (400) is of a hollow structure, and the inner cavity of the limiting pipeline (400) is divided into a plurality of mutually communicated limiting spaces (410); a liquid storage part (500) is arranged in the limit space (410), the liquid storage part (500) comprises a shell and a hollow cavity surrounded by the shell, wherein, The shell is provided with a plurality of micropores (510), and the liquid storage part (500) sucks liquid through the micropores (510) on the surface and stores the liquid in the hollow cavity; The liquid storage part (500) moves in the limiting space (410) under the pushing of liquid phase or gas phase, then liquid stored in the hollow cavity is separated from the liquid storage part (500) through the micropores (510), the separated liquid part is used for wetting the pipe wall, and part is transferred to the next limiting space (410).
  2. 2. The boiling heat exchange device suitable for long pipelines according to claim 1, wherein the limiting pipeline (400) is provided with a plurality of partition plates (420) along the axial direction thereof, the partition plates (420) divide the inner cavity of the limiting pipeline (400) into a plurality of limiting spaces (410), and the partition plates (420) are provided with through holes (421); the liquid storage part (500) moves in the limit space (410) under the pushing of the liquid phase or the gas phase and collides with the partition plate (420) so as to realize the transfer and redistribution of the liquid in the hollow cavity of the liquid storage part (500).
  3. 3. The boiling heat exchange device suitable for long pipelines as claimed in claim 2, wherein the axial dimension L2 of the limiting space (410) is 4-12 times of the axial dimension L1 of the liquid storage part (500).
  4. 4. The boiling heat exchange device suitable for long pipelines as claimed in claim 3, wherein the radial dimension D1 of the liquid storage part (500) is 0.80-0.98 times of the radial dimension D2 of the limiting space (410).
  5. 5. The boiling heat exchange device for long pipelines according to claim 1-4, wherein the pore diameter of the micropores (510) is 50-300 μm.
  6. 6. The boiling heat exchange device suitable for long pipelines according to claim 5, wherein the distance between two adjacent limit pipelines (400) is 2.3-2.6 times of the radius of the limit pipeline (400).
  7. 7. The boiling heat exchange device for long pipeline according to claim 1, wherein the inner sleeve (200) is arranged in the outer sleeve (100), wherein, The whole inner sleeve (200) is of a hollow structure, and the limit pipeline (400) is clamped in an annular channel (300) formed between the inner sleeve and the outer sleeve.
  8. 8. The boiling heat exchange device for long pipeline according to claim 7, wherein the liquid storage component (500) is of a spherical structure or a cylindrical structure.
  9. 9. The boiling heat exchange device for long pipeline according to claim 7 or 8, wherein the partition plate (420) is a sintered metal plate, and the heat conductivity of the liquid storage part (500) is not lower than 150W/(mK).
  10. 10. The method for using the boiling heat exchange device suitable for the long pipeline according to any one of the claims 1 to 9 is characterized in that the working flow is as follows, Firstly, fluid in a pipeline flows along the pipeline in a liquid single-phase form and is heated by the pipeline wall, micropores (510) and pore structures on the surface of a liquid storage component (500) can provide more nucleation sites, and the system enters a two-phase flow stage of nucleate boiling in advance; at the same time, the micropores (510) can absorb and store part of the liquid into the hollow cavity of the liquid storage component (500) under the action of capillary action; Then, when the two phases are developed until the gas phase content is increased, the liquid storage part (500) continuously rolls under the pushing of the fluid and the gas phase and collides with the bubbles, and the liquid storage part is sheared and disturbed, so that the large bubbles are crushed into smaller bubbles again, and the two-phase heat exchange capacity is maintained; Then, the fluid continuously absorbs heat along the way, the gas phase content is gradually increased, and the liquid phase content of the wall surface is gradually reduced and finally developed into continuous air film coverage; Along with the continuous forward movement of the liquid storage component (500), the liquid storage component (500) collides with the partition plate (420) and throws out the liquid in the liquid storage component (500) through the micropores (510), wherein, a part of thrown-out liquid is directly supplied to the vicinity of the wall surface to realize rapid rewetting, and the other part enters the next limit space (410) through the through holes (421) on the partition plate (420) to form sectional liquid supplying and redistribution along the way.

Description

Boiling heat exchange device suitable for long pipeline and application method thereof Technical Field The invention belongs to the technical field of boiling heat exchange equipment, and particularly relates to a boiling heat exchange device suitable for a long pipeline and a use method thereof. Background In key equipment such as large-scale steam pipelines, main water supply pipelines and the like of nuclear power plants and thermal power plants, hundred-meter-level ultra-long conveying pipelines are commonly arranged, and the pipelines are in long-term service under high-temperature and high-pressure working conditions. The flow state and the phase state of the working medium in the pipeline can dynamically evolve along with the conveying distance under the continuous accumulation influence of the heat absorption of the pipeline, so that the problem of gradual attenuation of the heat transfer capacity of the pipeline along the pipeline is caused. On one hand, after the liquid in the pipe enters the boiling stage, the bubble generation, growth and detachment process is unstable, the bubble aggregation is easy to occur and large bubbles are formed, meanwhile, the phenomenon that the wall surface and the liquid working medium are blocked by an air film is more easy to occur in the high-dryness pipe section, the heat transfer resistance is directly increased greatly, and the heat exchange efficiency of the pipeline is obviously reduced. On the other hand, in the long-term operation process of the pipeline, the inner wall is easy to generate adhesion and scaling of medium sediment, so that extra heat transfer resistance is formed, the integral heat exchange performance of the pipeline is further weakened, and meanwhile, the operation stability of the whole power system is also adversely affected. Therefore, how to effectively improve the along-path heat transfer capacity of the overlength conveying pipeline, ensure the heat exchange efficiency, maintain the stable operation of the system and have important production practice significance. In the patent CN119412983a, a device for enhanced boiling heat exchange of particulate fluid is disclosed. This application includes a cooling channel having a cold surface and a hot surface, particles and a cooling medium flowable within the cooling channel, the particles including a particle shell and a core located within the particle shell, there being a cavity between the particle shell and the core in communication with an external cooling medium, the cavity being subject to bubble or bubble collapse by a temperature change between the cold surface and the hot surface, thereby changing the particle density for oscillating the particles between the cold surface and the hot surface. This application utilizes temperature changes to create bubbles or bubble collapse within the cavity which can reduce particle density while increasing particle buoyancy, and bubble collapse can increase particle density to promote oscillating movement of particles between the cold and hot surfaces. Although the heat transfer efficiency can be effectively improved in the application, in a high-dryness section, if the rewetting and fluid replacement strength caused by particle oscillation is insufficient to offset the wall phase change evaporation consumption, local drying still can occur, so that the heat exchange stability and the strengthening effect are affected. For another example, in CN113776377a, a boiling enhanced evaporation heat exchange tube, and a device and method for making the same are disclosed. In the application, on one hand, the turbulence ball is impacted by the fluid to continuously move, the air bubbles are continuously scattered, the air bubbles are prevented from being gathered to form an air film, so that film boiling is generated, the thermal resistance in the pipe is reduced, meanwhile, when the fluid passes through the turbulence ball, a karman vortex street effect is formed, the turbulence level of the fluid is increased, the field coordination level of the fluid is improved, and the heat transfer is effectively enhanced. On the other hand, by gradually increasing the surface wettability from the disturbance ball to the traction wire, the surface roughness gradually decreases. The liquid drop obtains the Laplace differential pressure driving force which moves from the disturbance ball to the inner wall surface of the pipe through the traction wire, the antigravity directional transportation of the liquid drop is realized, more liquid can be provided for the wall surface, the liquid supplement of the wall surface is promoted, the wettability of the boiling surface is enhanced, the internal phase distribution of the base pipe is regulated and controlled, and therefore the boiling heat transfer coefficient is enhanced. However, in this application, the continuous fluid replacement and rewetting support of the high-dryness area at the rear section may be insufficien