CN219978172U - Enhanced boiling heat transfer experimental device based on capillary force - Google Patents
Enhanced boiling heat transfer experimental device based on capillary force Download PDFInfo
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- CN219978172U CN219978172U CN202321095319.8U CN202321095319U CN219978172U CN 219978172 U CN219978172 U CN 219978172U CN 202321095319 U CN202321095319 U CN 202321095319U CN 219978172 U CN219978172 U CN 219978172U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The utility model belongs to the technical field of thin liquid film boiling phase transition heat transfer, and in particular relates to an intensified boiling heat transfer experimental device based on capillary force. Comprises a snake-shaped condensing tube, a digital display pressure gauge, an auxiliary heating rod, a condensing cover plate, an evaporation cavity, an evaporation base cover plate, a separable heating block and a rotary bracket. The device can be used for testing boiling heat transfer of different porous structures under vertical and different angles, can also be used for testing boiling heat transfer under different vacuum degrees, can also be used for testing boiling heat transfer of different working media, and the like. The device is ingenious in design, has high tightness, can be used for vacuumizing and pressure maintaining tests, and can be used for vertical and multi-angle experiments, multi-task tests and the like.
Description
Technical Field
The utility model relates to the technical field of thin liquid film boiling phase change heat transfer, in particular to a capillary force-based enhanced boiling heat transfer experimental device.
Background
From the mobile phone to the computer to the server, the heat flux density varies from a few watts per square centimeter to hundreds of watts or even up to kilowatts. As the current mainstream blade server single-chip CPU peak heat flow density is as high as 80-200W/cm 2 While the maximum heat dissipation capacity of air is about 37w/cm 2 For such electronic devices with high integration, high heat flux density and high performance, the problem of heat concentration is still to be solved. Electronic devices with high heat flux density are generally equipped with corresponding heat dissipation modules, which include heat pipes or temperature plates (VC), fins, interface materials, fans, etc. The heat pipe and the temperature equalizing plate are used as high heat conducting elements, and the performance quality of the heat pipe and the temperature equalizing plate is important to the influence of the heat radiation capacity of the heat radiation module. The heat pipe is generally composed of a pipe shell, a liquid suction core and a working medium. The liquid suction core is usually copper powder or copper mesh sintered porous structure, and the working medium comprises water, ethanol and the like. The working principle of the heat pipe is phase change heat transfer, and the heat pipe has the characteristics of high equivalent heat conductivity, excellent isothermal property, strong environmental adaptability and the like and is widely applied. The temperature equalizing plate is equivalent to a plurality of heat pipes which are connected side by side, two-dimensional heat conduction can be realized, and the heat transmission can be obviously improved. However, the heat transfer capability of the heat pipe and vapor chamber is also limited by various factors, and there is a heat transfer limit. According to the Cotter heat pipe theory, the heat pipe has capillary limit, boiling limit, carrying limit and the like. Where capillary limitation is the primary limiting factor in the maximum heat transfer capacity of a heat pipe. The capillary limit refers to the heat transfer limit of the heat pipe caused by the limitation of the capillary pressure provided by the wick structure for the circulation of the working medium, and is simply that the liquid amount carried back by the capillary force of the wick is smaller than the liquid evaporation amount at the heat source position.
The maximum heat transfer power of the heat pipe is obtained through a test, the test comprises a horizontal test and a reverse gravity test, the reverse gravity test is that a heat source is on the upper side and condensed on the lower side, and the test method can more truly obtain the heat transfer capacity of the heat pipe. When the heat pipe works against gravity, the working medium is changed into steam at the heat source position to take away heat, the steam flows to the condensation section due to internal pressure difference and condenses in the condensation section to release heat to be liquid, and then the liquid returns to the evaporation section above under the capillary action of the liquid suction core. To improve the heat pipe performance, increasing the critical heat flux density of the heat pipe or vapor chamber by improving the capillary driven boiling performance within the porous medium has received extensive attention from researchers. The thermal performance of a wick can be characterized by Critical Heat Flux (CHF), nucleate boiling Onset (ONB), and Heat Transfer Coefficient (HTC). In CHF testing, capillary forces play a major role, with capillary forces being inversely proportional to the effective capillary radius. However, a decrease in pore size results in a decrease in permeability and an increase in liquid flow resistance, while decreasing CHF or HTC. The contradictory problem between the higher capillary force and the greater permeability of the porous wick structure is a major factor limiting the heat transfer limit of the heat pipe.
Therefore, the boiling heat transfer mechanism of different porous structures under vertical and different angles and different working mediums is explored, and the method has important significance for enhancing the boiling heat transfer of porous media and improving the heat transfer performance of the liquid absorption core and solving the high-efficiency heat management problem of a high-power electronic system. However, this research is lacking in the field of heat exchange.
Disclosure of Invention
The technical problems to be solved are as follows: aiming at the lack of an experimental device for researching boiling heat transfer mechanisms of different porous structures under vertical and different angles and different working media in the prior art, the utility model provides a capillary force-based enhanced boiling heat transfer experimental device which can supplement the boiling enhanced heat transfer research of different wick structures under vertical and different angles, different vacuum degrees and different working media.
The technical scheme is as follows: an enhanced boiling heat transfer experimental device based on capillary force comprises a serpentine condenser tube, a digital display pressure gauge, an auxiliary heating rod, a condensing cover plate, an evaporation cavity, an evaporation base cover plate, a separable heating block and a rotary bracket,
the evaporation cavity comprises a front observation window, a right observation window, a left observation window and a cavity body, wherein the cavity body is a cube with an opening at the top end, a periphery and a closed bottom end, the right observation window and the left observation window are oppositely arranged on two side surfaces of the cavity body, the front observation window is arranged on the remaining one side surface of the cavity body, an evaporation base mounting square opening, an auxiliary heating rod mounting hole and a drainage threaded hole are formed in the remaining other side surface of the cavity body, the evaporation base mounting square opening is formed in the upper part of the remaining other side surface of the cavity body, the auxiliary heating rod mounting hole and the drainage threaded hole are sequentially formed in the bottom of the evaporation base mounting square opening, and the auxiliary heating rod mounting hole is used for connecting an auxiliary heating rod and movably and hermetically connected with the drainage threaded hole for drainage;
The condensing cover plate is arranged above the evaporating cavity and is movably and hermetically connected with the evaporating cavity, and comprises a cover plate body, a reducing branch pipe, an adding liquid opening and a digital display pressure gauge mounting threaded hole, wherein the reducing branch pipe, the adding liquid opening and the digital display pressure gauge mounting threaded hole are arranged on the upper surface of the cover plate body and penetrate through the cover plate body;
the rotary support is used for supporting the evaporation cavity and comprises a support panel and a rotary structure arranged at the bottom of the support panel, and the evaporation cavity is arranged at the top end of the support panel when the experimental device is used;
the evaporation base apron is connected with the evaporation cavity through evaporation base, and evaporation base is inside to correspond boss hollow boss piece, including protruding part and boss main part, protruding part installs square trompil and evaporation cavity scarf joint through evaporation base, and the boss main part is close to the one side and the evaporation cavity external surface contact of protruding portion, and evaporation base apron locates the boss main part and keeps away from the one side of protruding portion, and detachable heating piece locates the inside hollow of evaporation base, and detachable heating piece one end stretches into the evaporation cavity for heating the sample, and the other end is connected with the heating source.
Preferably, the separable heating block comprises a separable heating block upper part and a separable heating block lower part, wherein the evaporation base is provided with a separable heating block upper part mounting hole and a separable heating block lower part mounting hole, the separable heating block upper part mounting hole is annularly arranged at the inner part of the convex part and corresponds to the boss-shaped hollow front end and is used for installing the separable heating block upper part, the separable heating block lower part mounting hole is a boss-shaped hollow corresponding to the boss-shaped hollow inside the boss main body and is used for installing the separable heating block lower part, the separable heating block upper part comprises a square block, a cylinder arranged at the bottom center of the square block, a sample sintering surface and a bottom threaded hole, the sample sintering surface is arranged at the top of the square block and is used for testing samples, and the bottom threaded hole is arranged at the bottom of the cylinder;
the lower part of the separated heating block comprises a square main body, a nested hole and a through hole, the nested hole is arranged in the center of the square main body and does not penetrate through the square main body, the through hole is arranged in the center of the nested hole and penetrates through the square main body, the nested hole is used for nesting the bottom of the cylinder on the separated heating block, the square main body is connected with a heating source, and the lower part of the separated heating block and the upper part of the separated heating block are fixedly connected through bolts penetrating through the through hole and the bottom threaded hole in a matched manner.
Preferably, the condensation cover plate is movably and hermetically connected with the evaporation cavity through a bolt a, wherein the top end of the evaporation cavity is provided with a plurality of evaporation cavities and condensation cover plate connecting through holes with internal threads matched with the outer surface of the bolt a, the bottom of the condensation cover plate is provided with a plurality of groups of evaporation cavity connecting through holes with internal threads matched with the outer surface of the thread a, corresponding to the evaporation cavities and the condensation cover plate connecting through holes, and the bolt a is used for connecting the evaporation cavities with the condensation cover plate connecting through holes and the evaporation cavity connecting through holes;
the evaporation base cover plate is connected with the evaporation cavity through the evaporation base through the bolt b, a plurality of groups of internal threads and bolt b external surface matched connecting holes are formed in the periphery of the evaporation base cover plate, a plurality of groups of internal threads and bolt b external surface matched evaporation base fixing holes are formed in the positions corresponding to the evaporation base, the evaporation cavity comprises a plurality of groups of internal threads and bolt b external surface matched evaporation base fixing threaded holes, the internal threads and the bolt b external surface matched evaporation base fixing threaded holes are uniformly distributed in the periphery of the outer side of the square opening of the evaporation base installation and correspond to the evaporation base fixing holes, and the bolt b is used for connecting the connecting holes, the evaporation base fixing holes and the evaporation base fixing threaded holes.
Preferably, the rotating structure comprises a supporting seat, a locking bolt and a rotating part, wherein the rotating part is rotationally connected with the supporting seat through the locking bolt, and the supporting panel is arranged on the upper surface of the rotating part.
Preferably, the contact surface of the condensation cover plate and the evaporation cavity, the contact surface of the evaporation base and the evaporation cavity and the contact surface of the separation type heating block with the evaporation base are provided with sealing elements, the contact surface of the condensation cover plate and the evaporation cavity and the sealing elements at the contact surface of the separation type heating block with the evaporation base are sealing gaskets, the edge of the opening at the top end of the evaporation cavity is provided with a sealing groove, the sealing groove is used for embedding the sealing gaskets, and the sealing gaskets are made of silicon rubber, fluorosilicone rubber, nylon, polyurethane or engineering plastics.
Preferably, the heating source under the separated heating block is a ceramic heating plate, the ceramic heating plate is attached to the periphery of the outer edge of the square main body and is connected with an external power supply through a lead wire, the separated heating block further comprises a heat preservation material, the heat preservation material is wrapped on the outer side of the ceramic heating plate, and the heat preservation material is heat preservation cotton or aerogel felt.
Preferably, the capillary force-based enhanced boiling heat transfer experimental device further comprises a high-speed camera, wherein the high-speed camera is fixed right in front of the front observation window and used for shooting evaporation and boiling phenomena of the surface of the porous structure in the cavity, the front observation window, the right observation window and the left observation window are made of transparent toughened glass, a transparent heating film is adhered to the outer side of the transparent toughened glass and used for preventing atomization of the observation window, and light sources are arranged on the two sides of the right observation window and the left observation window and used for illuminating from the left side or the right side observation window respectively.
Preferably, the evaporation cavity further comprises a steam temperature thermocouple installation hole and a working medium temperature thermocouple installation threaded hole, the steam temperature thermocouple installation hole is formed in the top of the other side face of the cavity body, the working medium temperature thermocouple installation threaded hole is formed in the bottom of the square opening of the evaporation base, the working medium temperature thermocouple installation threaded hole is used for being connected with a working medium temperature thermocouple, the steam temperature thermocouple installation hole is used for being connected with the steam temperature thermocouple, and the working medium temperature thermocouple and the steam temperature thermocouple are connected with the data acquisition module through leads;
the split type heating block further comprises three thermocouples and three equidistant thermocouple mounting holes corresponding to the thermocouples, wherein the three equidistant thermocouple mounting holes are equidistantly formed in the axial outer surface of the cylinder and are used for mounting the three thermocouples, and the three thermocouples are connected with the data acquisition module through leads;
the evaporation base cover plate also comprises a thermocouple and ceramic heating plate line opening which is arranged in the center of the evaporation base cover plate and is used for leading wires through the thermocouple and the ceramic heating plate;
a thermocouple circuit fixing groove is formed in the hollow part of the inside of the evaporation base and is used for fixing leads connected with three thermocouples;
The intensified boiling heat transfer experimental device based on capillary force also comprises a data acquisition module, wherein the input end of the data acquisition module is respectively and electrically connected with the data output ends of the three thermocouples on the measuring working medium temperature thermocouple, the measuring steam temperature thermocouple and the additional heating block.
Preferably, the sample is a wick structure comprising at least one of a multi-layered copper mesh sintering, a metal foam, a machined channel, and a chemically modified (e.g., electrochemical) surface.
The beneficial effects are that: (1) The utility model relates to an experimental device for boiling heat transfer of a thin liquid film, which is different from the traditional boiling device in that a porous structure of a heating area is not contacted with liquid, and phase change heat exchange is realized by completely relying on capillary force of a porous medium during heat exchange test of the porous structure. In addition, the utility model can test the phase change heat exchange at different angles through the adjustment of the rotary support, and the porous structure at the moment presents a certain included angle with the liquid level.
(2) Compared with the traditional experimental device, the device can study the boiling heat transfer effect under different vacuum degrees by changing the vacuum degree in the evaporation cavity.
(3) Compared with the traditional experimental device, the device adopts the vacuum visualized experimental device for boiling heat transfer, and the visual window of the device is stuck with the transparent heating film, so that the influence of water mist generated when the phase change occurs to the working medium in the evaporation cavity can be effectively prevented.
(4) Compared with the traditional experimental device, the device adopts the separated design of the heating block, and can directly sinter the test piece on the heating surface, thereby reducing the contact thermal resistance. And the lower part of the heating block is provided with a threaded hole, and the device can be self-locked by bolts, so that high tightness of the device is realized.
(5) Compared with the traditional experimental device, the device can study the boiling heat transfer effect of different working media by changing the working media.
(6) The utility model belongs to film boiling, and is different from pool boiling in that a test sample in the experimental device is not submerged by liquid and pumps the liquid into the test sample completely by virtue of capillary force, the liquid in the pool boiling device completely submerges the test sample, the liquid enters the sample and has capillary force, the pressure of the liquid exists at the same time, in addition, the liquid in the pool boiling is easy to be contacted by a heating table, so that the problems of heat leakage and the like are caused, and experimental data are generated. Therefore, the experimental device of the utility model completely solves the problem of pool boiling.
Drawings
FIG. 1 is a schematic diagram of an experimental apparatus according to an embodiment of the present utility model;
FIG. 2 is a cross-sectional view taken along the A-A plane of FIG. 1;
FIG. 3 is a schematic view of a steam chamber according to the present utility model;
FIG. 4 is a schematic view of a condensing cover plate according to the present utility model;
FIG. 5a is a schematic top view of an evaporation base according to the present utility model;
FIG. 5b is a schematic view of the bottom surface of an evaporation base according to the present utility model;
FIG. 6 is a schematic view of an upper portion of a split heating block according to the present utility model;
FIG. 7 is a schematic view of a lower portion of a split heating block according to the present utility model;
FIG. 8 is a schematic view of an evaporation cover plate according to the present utility model;
FIG. 9 is a schematic view of a rotating bracket according to the present utility model;
fig. 10 is a graph of test results of an application example, in which (a) is a relationship curve of superheat and heat flux density, and (b) is a relationship curve of heat flux density and heat exchange coefficient.
The numerical references in the drawings are as follows: 1. an evaporation cavity; 2. a condensing cover plate; 3. a rotating bracket; 4. an evaporation base; 5. evaporating a base cover plate; 6. on the separated heating block; 7. under the separated heating block; 8. a front viewing window; 9. a right viewing window; 10. auxiliary heating rod mounting holes; 11. a drain screw hole; 12. measuring a working medium temperature thermocouple mounting threaded hole; 13. the evaporation base is provided with a square opening; 14. the evaporation base is fixed with a threaded hole; 15. measuring a steam temperature thermocouple mounting hole; 16. a left observation window; 17. sealing the groove; 18. the evaporation cavity and the condensation cover plate are connected with the through holes; 19. a reducing branch pipe; 20. opening holes by adding liquid; 21. the through hole is connected with the evaporation cavity; 22. a digital display pressure gauge is provided with a threaded hole; 23. an evaporation base fixing hole; 24. the upper part of the separated heating block is provided with a mounting hole; 25. a thermocouple circuit fixing groove; 26. mounting holes at the lower part of the separated heating block; 27. the upper part of the heating block is provided with a sample sintering surface; 28. equidistant thermocouple mounting holes; 29. a bottom threaded hole; 30. a sleeve hole; 31. a through hole; 32. a thermocouple and a ceramic heating plate line opening; 33. a connection hole; 34. and (5) screwing the bolts.
Detailed Description
The utility model is further described below with reference to the drawings and specific embodiments.
Example 1
The utility model provides an intensive boiling heat transfer experimental apparatus based on capillary force, see fig. 1-9, includes snakelike condenser tube, digital display manometer, auxiliary heating stick, condensation apron 2, evaporation cavity 1, evaporation base 4, evaporation base apron 5, separable heating piece and runing rest 3.
The evaporation cavity 1 comprises a front observation window 8, a right observation window 9, a left observation window 16 and a cavity body, wherein the cavity body is a cube with an opening at the top end, four sides and a closed bottom end, the right observation window 9 and the left observation window 16 are oppositely arranged on two sides of the cavity body, the front observation window 8 is arranged on the remaining side of the cavity body, an evaporation base mounting square opening 13, an auxiliary heating rod mounting hole 10 and a drainage threaded hole 11 are arranged on the remaining side of the cavity body, the evaporation base mounting square opening 13 is arranged on the upper portion of the remaining side of the cavity body, the auxiliary heating rod mounting hole 10 and the drainage threaded hole 11 are sequentially arranged on the bottom of the evaporation base mounting square opening 13, the auxiliary heating rod mounting hole 10 is used for connecting an auxiliary heating rod, and the drainage threaded hole 11 is movably and hermetically connected for drainage.
The condensing cover plate 2 is arranged above the evaporating cavity 1 and is movably and hermetically connected with the evaporating cavity 1, and comprises a cover plate body, a reducing branch pipe 19, an adding liquid opening 20 and a digital display pressure gauge mounting threaded hole 22, wherein the reducing branch pipe 19, the adding liquid opening 20 and the digital display pressure gauge mounting threaded hole 22 are arranged on the upper surface of the cover plate body and penetrate through the cover plate body, the digital display pressure gauge mounting threaded hole 22 is used for connecting a digital display pressure gauge, one end of a vapor condensing part of the serpentine condenser pipe is connected with the reducing branch pipe 19 in a nested manner, the other end of the serpentine condenser pipe is used for connecting a vacuumizing system, a water inlet and outlet of the serpentine condenser pipe is connected with a low-temperature constant-temperature tank, and the adding liquid opening 20 is used for adding working liquid.
The rotary support 3 is used for supporting the evaporation cavity 1, and comprises a support panel and a rotary structure arranged at the bottom of the support panel, and the evaporation cavity 1 is arranged at the top end of the support panel when the experimental device is used.
The evaporation base apron 5 is connected with evaporation cavity 1 through evaporation base 4, evaporation base 4 is inside to correspond the hollow boss piece of boss shape, including protruding part and boss main part, protruding part is through evaporation base installation square trompil 13 and evaporation cavity 1 scarf joint, the boss main part is close to the one side and the evaporation cavity 1 surface contact of protruding part, evaporation base apron 5 locates the boss main part one side of keeping away from protruding part, detachable heating piece locates evaporation base 4 inside hollow, and detachable heating piece one end stretches into evaporation cavity 1 for the heating sample, the other end is connected with the heating source.
As a preferred scheme of the utility model, the separable heating block comprises a separable heating block upper part 6 and a separable heating block lower part 7, the evaporation base 4 is provided with a separable heating block upper part mounting hole 24 and a separable heating block lower part mounting hole 26, the separable heating block upper part mounting hole 24 is annularly arranged at the inner part of the protruding part and corresponds to the boss-shaped hollow front end and is used for mounting the separable heating block upper part 6, the separable heating block lower part mounting hole 26 is in the boss main body and corresponds to the boss-shaped hollow and is used for mounting the separable heating block lower part 7, the separable heating block upper part 6 comprises a square block, a cylinder arranged at the bottom center of the square block, a sample sintering surface 27 and a bottom threaded hole 29, the sample sintering surface 27 is arranged at the top of the square block and is used for testing samples, and the bottom threaded hole 29 is arranged at the bottom of the cylinder;
the lower 7 of the separated heating block comprises a square main body, a nesting hole 30 and a through hole 31, wherein the nesting hole 30 is arranged at the center of the square main body and does not penetrate through the square main body, the through hole 31 is arranged at the center of the nesting hole 30 and penetrates through the square main body, the nesting hole 30 is used for nesting the bottom of the upper 6 cylinder of the separated heating block, the square main body is connected with a heating source, and the upper 6 part of the separated heating block and the lower 7 of the separated heating block penetrate through bolts and the through hole 31 and the bottom threaded hole 29 are fixedly connected in a matched mode.
As a preferred scheme of the utility model, the condensation cover plate 2 and the evaporation cavity 1 are movably and hermetically connected through a bolt a, wherein the top end of the evaporation cavity 1 is provided with a plurality of evaporation cavities with internal threads matched with the outer surface of the bolt a and condensation cover plate connecting through holes 18, the bottom of the condensation cover plate 2 is provided with a plurality of groups of evaporation cavity connecting through holes 21 with internal threads matched with the outer surface of the thread a, corresponding to the evaporation cavities and the condensation cover plate connecting through holes 18, and the bolt a is used for connecting the evaporation cavities with the condensation cover plate connecting through holes 18 and the evaporation cavity connecting through holes 21;
the evaporation base cover plate 5 is connected with the evaporation cavity 1 through the evaporation base 4 through the bolt b, a plurality of groups of internal threads and bolt b outer surface matched connecting holes 33 are formed in the periphery of the evaporation base cover plate 5, a plurality of groups of internal threads and bolt b outer surface matched evaporation base fixing holes 23 are formed in the positions corresponding to the evaporation base 4, the evaporation cavity 1 comprises a plurality of groups of internal threads and bolt b outer surface matched evaporation base fixing threaded holes 14, the evaporation base fixing threaded holes 14 are uniformly distributed in the periphery of the outer side of the evaporation base installation square opening 13 and correspond to the positions of the evaporation base fixing holes 23, and the bolts b are used for connecting the connecting holes 33, the evaporation base fixing holes 23 and the evaporation base fixing threaded holes 14.
As a preferred embodiment of the present utility model, the rotating structure includes a supporting seat, a locking bolt 34, and a rotating portion rotatably connected to the supporting seat through the locking bolt 34, and the supporting panel is disposed on an upper surface of the rotating portion.
As another preferred scheme of the utility model, the contact surface of the condensation cover plate 2 and the evaporation cavity 1, the contact surface of the evaporation base 4 and the evaporation cavity 1 and the contact surface of the separation type heating block 6 and the evaporation base 4 are all provided with sealing elements, the sealing elements at the contact surface of the condensation cover plate 2 and the evaporation cavity 1 and the contact surface of the separation type heating block 6 and the evaporation base 4 are sealing gaskets, the edge of the opening at the top end of the evaporation cavity 1 is provided with a sealing groove 17, the sealing groove 17 is used for embedding the sealing gaskets, and the sealing gaskets are made of silicon rubber, fluorosilicone rubber, nylon, polyurethane or engineering plastics.
As another preferable scheme of the utility model, the heating source of the lower part 7 of the separated heating block is a ceramic heating plate, the ceramic heating plate is stuck to the periphery of the outer edge of the square main body and is connected with an external power supply through a lead wire, the lower part 7 of the separated heating block also comprises a heat preservation material, the heat preservation material is wrapped on the outer side of the ceramic heating plate, and the heat preservation material is heat preservation cotton or aerogel felt.
As another preferred scheme of the utility model, the enhanced boiling heat transfer experimental device based on capillary force further comprises a high-speed camera, wherein the high-speed camera is fixed right in front of the front observation window 8 and is used for shooting evaporation and boiling phenomena of the porous structure surface in the cavity, the front observation window 8, the right observation window 9 and the left observation window 16 are transparent toughened glass, transparent heating films are adhered to the outer sides of the transparent toughened glass and are used for preventing the observation windows from being atomized, and light sources are arranged on two sides of the right observation window 9 and the left observation window 16 and are respectively used for illuminating from the left or right observation windows.
As another preferred solution of the present utility model, the evaporation cavity 1 further includes a measurement steam temperature thermocouple installation hole 15 and a measurement working medium temperature thermocouple installation threaded hole 12, the measurement steam temperature thermocouple installation hole 15 is disposed at the top of the remaining other side surface of the cavity body, the measurement working medium temperature thermocouple installation threaded hole 12 is disposed at the bottom of the evaporation base installation square opening 13, the measurement working medium temperature thermocouple installation threaded hole 12 is used for connecting with a measurement working medium temperature thermocouple, the measurement steam temperature thermocouple installation hole 15 is used for connecting with a measurement steam temperature thermocouple, and the measurement working medium temperature thermocouple and the measurement steam temperature thermocouple are connected with the data acquisition module through leads.
The split type heating block 6 further comprises three thermocouples and three equidistant thermocouple mounting holes 28 corresponding to the thermocouples, and the three equidistant thermocouple mounting holes 28 are equidistantly arranged on the axial outer surface of the cylinder and used for mounting the three thermocouples, and the three thermocouples are connected with the data acquisition module through leads. The thermocouple includes a hot end, i.e., the measurement end, for direct temperature measurement, and a cold end, which is embedded in the thermocouple mounting hole 28 and secured with a copper foil tape. The cold end of the thermocouple is connected with the data acquisition module through a lead wire, and the data acquisition module can display the temperature value acquired by the hot end in real time.
The evaporating base cover plate 5 further comprises a thermocouple and ceramic heating plate line opening 32 arranged in the center of the evaporating base cover plate 5 and used for leading wires through the thermocouple and the ceramic heating plate.
The evaporation base 4 is internally provided with a thermocouple circuit fixing groove 25 at the hollow part, and the thermocouple circuit fixing groove 25 is used for fixing external leads of three thermocouples.
The intensified boiling heat transfer experimental device based on capillary force also comprises a data acquisition module, wherein the input end of the data acquisition module is electrically connected with the data output ends of the thermocouple for measuring the temperature of the working medium, the thermocouple for measuring the temperature of steam and the other three thermocouples respectively.
As another preferred aspect of the present utility model, the sample is a wick structure comprising at least one of a multi-layered copper mesh sintering, a metal foam, a machined channel, and a chemically modified surface such as electrochemical.
The experimental method of the device comprises the following steps:
sintering a sample to be tested on a sample sintering surface 27 of a separated heating block 6 at 850 ℃ in an atmosphere furnace, then assembling the separated heating block 6 on an evaporation base 4 from a cylinder end through a part of a mounting hole 24 on the separated heating block, then mounting a lower part 7 of the separated heating block on the evaporation base 4, connecting the lower part 7 of the separated heating block with the separated heating block 6 through bolts, fixedly connecting an evaporation base cover plate 5, the evaporation base 4 and an evaporation cavity 1, then sealing and connecting a condensation cover plate 2 and the upper surface of the evaporation cavity 1 to form a closed space in the evaporation cavity 1, and then mounting a snake-shaped condensation pipe, a digital display pressure gauge and an auxiliary heating rod to corresponding positions;
step two, injecting working liquid into the evaporation cavity 1 through the liquid adding opening 20, wherein the liquid height is flush with the upper surface and the lower surface of the separated heating block 6, starting the heating rod, and heating the temperature of the working liquid to the saturation temperature under the current atmospheric pressure;
Step three, connecting a serpentine condenser pipe with the low-temperature constant-temperature tank, opening cooling circulating water, and condensing steam by the condenser pipe to keep the water quantity in the test consistent, so that the pressure is kept constant in the whole test process, and the saturated environment in the cavity of the whole test process is kept;
analyzing the thermal performance of the test sample, gradually increasing the input power of a heating source, increasing the temperature of the separable heating block along with the increase of the thermal load, defining that the power reaches a steady state when the temperature change is not more than 0.1 ℃ within 10min, and recording all data;
and fifthly, testing the critical heat flow density of the sample, continuously increasing the power of the heat source until the sample is completely burnt, closing the heating source at the moment, and ending the test of the sample.
Application example 1
As shown in fig. 1-9, the enhanced boiling heat transfer experimental device based on capillary force comprises an evaporation cavity 1, a condensation cover plate 2, a rotary support 3, an evaporation base 4, an evaporation base cover plate 5, a separable heating block, a serpentine condenser tube, a digital display pressure gauge, an auxiliary heating rod and a data acquisition module.
The evaporating cavity 1 is connected with a vacuumizing system, so that boiling heat transfer performance of the porous structure in different vacuum degrees can be studied.
The evaporation cavity 1 can be made of stainless steel or aluminum alloy, the outer contour dimension of the bottom is 120mm multiplied by 120mm, the wall thickness is 10mm, and the height is 115mm. The evaporation cavity 1 is provided with a front observation window 8, a right observation window 9, a left observation window 16, a high-speed camera and a cavity body, the cavity body is a cube with an opening at the top end, four sides and a closed bottom end, the right observation window 9 and the left observation window 16 are oppositely arranged on two sides of the cavity body and used for illumination of a light source, the front observation window 8 is arranged on the remaining side of the cavity body, the remaining side of the cavity body is provided with an evaporation base mounting square opening 13, an auxiliary heating rod mounting hole 10, a drainage threaded hole 11, a measuring working medium temperature thermocouple mounting threaded hole 12, a measuring steam temperature thermocouple mounting hole 15, an evaporation base fixing threaded hole 14, a sealing groove 17, an evaporation cavity and a condensation cover plate connecting through hole 18, wherein the evaporation base mounting square opening 13 is arranged on the upper portion of the remaining side of the cavity body, the auxiliary heating rod mounting hole 10 and the drainage threaded hole 11 are sequentially arranged on the bottom of the evaporation base mounting square opening 13, the auxiliary heating rod mounting hole 10 is used for connecting an auxiliary heating rod, the auxiliary heating rod is used for heating temperature to a saturated state, the drainage threaded hole 11 is movably connected in a sealing mode, the measuring steam temperature thermocouple is used for measuring the temperature of the remaining side of the cavity body, the measuring the temperature thermocouple mounting hole is connected with the other side of the evaporation base mounting square opening 12, the measuring the temperature thermocouple is connected with the measuring the temperature thermocouple through the measuring thermocouple, and the temperature thermocouple is connected with the top of the measuring temperature thermocouple, and the temperature thermocouple is connected with the top of the thermocouple, the measuring the temperature thermocouple is connected with the thermocouple, and the temperature thermocouple is connected with the top, and the temperature thermocouple is connected with the thermocouple. The sealing groove 17 is arranged at the edge of the opening at the top end of the evaporation cavity 1, the sealing groove 17 is used for embedding a sealing gasket, and the sealing gasket is made of silicon rubber, fluorosilicone rubber, nylon, polyurethane or engineering plastics.
The digital display pressure gauge is used for detecting the pressure in the evaporating cavity, and the auxiliary heating rod is used for auxiliary heating of working media.
The front observation window 8, the right observation window 9 and the left observation window 16 are made of transparent toughened glass, transparent heating films are adhered to the outer sides of the transparent toughened glass and used for preventing the observation windows from being atomized, and light sources are arranged on two sides of the right observation window 9 and the left observation window 16 and used for illuminating from the left or right observation windows respectively.
The high-speed camera is fixed in front of the front observation window 8 and is used for shooting the evaporation and boiling phenomena of the surface of the porous structure in the cavity.
The condensing cover plate 2 is arranged above the evaporating cavity 1 and is movably and hermetically connected with the evaporating cavity 1, and comprises a cover plate body, a reducing branch pipe 19, an additive liquid opening 20, a connecting through hole 21 with the evaporating cavity and a digital display pressure gauge mounting threaded hole 22. The cover plate body thickness is 10mm, and cross section side length is 140mm, and reducing branch pipe 19, add liquid trompil 20 and digital display manometer installation screw hole 22 are located the cover plate body upper surface and are run through the cover plate body, and digital display manometer installation screw hole 22 is used for connecting the digital display manometer, and the digital display manometer is used for detecting evaporation cavity pressure. One end of the vapor condensing part of the serpentine condensing tube is connected with the reducing branch tube 19 in a nested way, the contact surface of the reducing branch tube 19 and the condensing tube is sealed by sealant, the other end of the serpentine condensing tube is connected with a vacuumizing system, and the water inlet and outlet of the serpentine condensing tube is connected with a low-temperature constant-temperature tank and used for condensing vapor so as to keep the pressure in the evaporating cavity constant. The liquid adding opening 20 is used for adding working liquid and is a KF25 fast interface, and the KF25 blind plate and the KF25 cutting sleeve can be sealed, so that the disassembly and the assembly are convenient.
The condensing cover plate 2 and the evaporating cavity 1 are movably and hermetically connected through a bolt a, wherein a plurality of evaporating cavities and condensing cover plate connecting through holes 18 with internal threads matched with the outer surfaces of the bolt a are formed in the top end of the evaporating cavity 1, a plurality of evaporating cavity connecting through holes 21 with the internal threads matched with the outer surfaces of the threads a, corresponding to the evaporating cavities and the condensing cover plate connecting through holes 18, are formed in the bottom of the condensing cover plate 2, and the bolt a is used for connecting the evaporating cavities, the condensing cover plate connecting through holes 18 and the evaporating cavity connecting through holes 21.
The rotary support 3 is used for supporting the evaporation cavity 1 and comprises a support panel and a rotary structure arranged at the bottom of the support panel, and the top end of the support panel is connected with the bottom of the evaporation cavity 1. The rotating structure comprises a supporting seat, a locking bolt 34 and a rotating part, wherein the rotating part is rotationally connected with the supporting seat through the locking bolt 34, and the supporting panel is arranged on the upper surface of the rotating part. The rotary support 3 is made of stainless steel or other metal materials, the side length of the cross section is 150mm, the width is 120mm, and the total height is 80mm, and is used for supporting the evaporation cavity 1. The rotating bracket 3 can adjust the inclination angle through the connected fastening bolt 34, can realize 0-90 degrees of rotation and is used for adjusting the angle between the test sample and the vertical direction.
The evaporating base cover plate 5 is connected with the evaporating cavity 1 through the evaporating base 4. The evaporation base cover plate 5 is connected with the evaporation cavity 1 through the evaporation base 4 through the bolt b, a plurality of groups of internal threads and bolt b outer surface matched connecting holes 33 are formed in the periphery of the evaporation base cover plate 5, a plurality of groups of internal threads and bolt b outer surface matched evaporation base fixing holes 23 are formed in the positions corresponding to the evaporation base 4, the evaporation cavity 1 comprises a plurality of groups of internal threads and bolt b outer surface matched evaporation base fixing threaded holes 14, the evaporation base fixing threaded holes 14 are uniformly distributed in the periphery of the outer side of the evaporation base installation square opening 13 and correspond to the positions of the evaporation base fixing holes 23, and the bolts b are used for connecting the connecting holes 33, the evaporation base fixing holes 23 and the evaporation base fixing threaded holes 14. Wherein, the contact surface of the evaporation base 4 and the evaporation cavity 1 is provided with a sealing gasket to prevent air leakage.
The evaporation base 4 is a hollow boss block with a boss shape corresponding to the inside, and comprises a boss and a boss main body, wherein the boss is in scarf joint with the evaporation base 4 through an evaporation base mounting square opening 13, one surface of the boss main body, which is close to the boss, is in contact with the outer surface of the evaporation cavity 1, the evaporation base cover plate 5 is arranged on one surface, which is far away from the boss, of the boss main body, the detachable heating block is arranged at the hollow part inside the evaporation base 4, one end of the detachable heating block extends into the evaporation cavity 1 and is used for heating a sample, and the other end of the detachable heating block is connected with a heating source. The evaporation base 4 is PEEK, polytetrafluoroethylene or other material. The boss main body is 50mm in height, the side length of the cross section of the boss at the bottom is 70mm, and the boss main body is larger than an evaporation base installation square hole reserved in the evaporation cavity 1. The boss bulge is 20mm in height and the side length of the section is 30mm. The distance between the evaporation base and the inner bottom surface of the evaporation cavity is 30-50mm.
The separated heating block comprises an upper heating block part 6 and a lower heating block part 7, and is made of T2 red copper for heat conduction. The evaporation base 4 is provided with a split type heating block upper part mounting hole 24 and a split type heating block lower part mounting hole 26, the split type heating block upper part mounting hole 24 is annularly arranged at the front end of the boss corresponding to the boss shape inside the boss, and is used for mounting the upper part of the split type heating block 6, and the split type heating block lower part mounting hole 26 is hollow corresponding to the boss shape inside the boss body and is used for mounting the lower part of the split type heating block 7.
The split type heating block 6 comprises a square block, a cylinder arranged at the center of the bottom of the square block, a sample sintering surface 27, three thermocouples, three equidistant thermocouple mounting holes 28 and a bottom threaded hole 29, wherein the three equidistant thermocouple mounting holes 28 and the bottom threaded hole 29 are corresponding to the sample sintering surface 27, the sample sintering surface 27 is arranged at the top of the square block, a test sample is sintered to the sintering surface 27 through a high-temperature sintering process, the bottom threaded hole 29 is arranged at the bottom of the cylinder, the three equidistant thermocouple mounting holes 28 are equidistantly arranged on the axial outer surface of the cylinder and are used for mounting the three thermocouples, and the three thermocouples are connected with an external temperature acquisition instrument through leads. The sample is in various wick structures including at least one of multi-layer copper mesh sintering, metal foam, machined channels, and chemically modified (e.g., electrochemical) surfaces. The square block has a thickness of 2mm, the bottom cylinder has a diameter of 10mm and a height of 33mm, wherein 10mm is inserted into the nesting hole 30 in the lower part 7 of the heating block for cooperation. The bottom threaded hole 29 has a thread depth of 10mm for M4 metric. The distance between the three thermocouple mounting holes was 5mm, with the uppermost thermocouple mounting hole being 10mm from the sample sintering face 27.
The lower part 7 of the separated heating block comprises a square main body, a nesting hole 30, a through hole 31, a ceramic heating plate and a heat preservation material, wherein the nesting hole 30 is arranged at the center of the square main body and does not penetrate through the square main body, the through hole 31 is arranged at the center of the nesting hole 30 and penetrates through the square main body, and the nesting hole 30 is used for nesting the bottom of the 6 cylinder on the separated heating block. An M4 bolt is connected with the bottom threaded hole 29 through the through hole 31, so that the lower part 7 of the split type heating block is contacted with the upper part 6 of the split type heating block, and self-locking connection is realized. In order to reduce the contact thermal resistance between the upper and lower parts of the split-type heating block, a heat conducting paste is coated in the nested holes 30. The external profile of the separated heating block 7 is a square body with the side length of 20mm, the diameter of the nesting hole 30 is 10.2mm, the depth is 10mm, the diameter of the through hole 31 is 4.2mm, and the depth is 10mm. The ceramic heating plate is attached to the periphery of the square main body, is connected with an external power supply through a lead wire, and is wrapped with a heat-insulating material which is heat-insulating cotton or aerogel felt.
The inside cavity department of evaporation base 4 is equipped with thermocouple circuit fixed slot 25, thermocouple circuit fixed slot 25 is used for fixed and three thermocouple connection's lead wire.
The evaporating base cover plate 5 further comprises a thermocouple and ceramic heating plate line opening 32 arranged in the center of the evaporating base cover plate 5 and used for leading wires through the thermocouple and the ceramic heating plate.
The thermocouple mounting holes 28 are arranged at 5mm intervals and have a hole size of 0.5-1mm. The thermocouple in the embodiment is of a T-shaped thermocouple, the thermocouple is fixed by using a copper foil adhesive tape after being installed, and the thermocouple is connected with the data acquisition module and can acquire the temperature of the heating block. The upper part 6 and the lower part 7 of the separated heating block are connected with the evaporation base 4 through a through hole 31 penetrating through the lower part by a bolt, wherein a sealing gasket is arranged at the contact part of the upper part 6 of the heating block and the evaporation base to prevent air leakage.
The input end of the data acquisition module is respectively and electrically connected with the data output ends of the working medium temperature thermocouple, the steam temperature thermocouple and the other three thermocouples, and is used for recording temperature changes in experiments.
In the experimental process, the evaporating cavity 1 can be filled with different phase-change working media, such as distilled water, fluoridized liquid, ethanol or one of other refrigerants, so as to explore the heat transfer influence and mechanism of the working media on vertical boiling.
Experimental procedure
In the experiment process, a multi-layer sintered copper net is used as a sample, deionized water is used as working liquid, and the enhanced boiling experiment under the vertical state of the sample is tested.
(1) Firstly, 6 layers of 300-mesh copper mesh are sintered on a sample sintering surface 27 of a separated heating block 6 at 850 ℃ in an atmosphere furnace, the sample size is 14 mm by 25mm, then 3 thermocouples are arranged on the separated heating block 6 and assembled on an evaporation base 4, and the upper part and the lower part of the separated heating block are fixedly connected with the evaporation base 4 through M4 bolts.
(2) And (3) installing the connected part in the step (1) to an evaporation base installation square opening 13 of the evaporation cavity 1, and adding a silica gel gasket between the evaporation base 4 and the evaporation cavity 1 for sealing. And injecting the degassed deionized water into the evaporation cavity 1, wherein the liquid height is lower than that of the separated heating block and is only flush with the lower surface of the boss of the evaporation base. Thus, the liquid on the upper surface of the heating block can be supplemented by the capillary force of the porous structure. After the above steps are completed, the sample and the liquid surface form an included angle of 90 degrees, and the vertical test is performed. To completely remove non-condensable gases, deionized water is heated to a severe boiling for at least 1.5 hours.
(3) And heating the liquid pool temperature to the saturation temperature under the current atmospheric pressure under the action of an auxiliary heating rod, and measuring the liquid temperature and the steam temperature value through a working medium temperature thermocouple and a steam temperature thermocouple.
(4) The serpentine condenser pipe is connected, the cooling circulating water is opened, and the condenser pipe condenses steam to keep the water quantity consistent in the test process, so that the pressure keeps a certain value in the whole test process, and the saturated environment in the whole test process cavity is kept.
(5) To analyze the thermal performance of the test samples, a DC power supply was used to step up the input power to the ceramic heater chip. The temperature of the heating block gradually increased with increasing thermal load, when the temperature change did not exceed 0.1 ℃ within 10 minutes, which was defined as reaching steady state at that power, all data were recorded.
(6) To test the critical heat flux density of the sample, the heat source power is continuously increased until complete burn-out, which is defined as a sudden rise in the temperature collected by the three thermocouples, is achieved, and the heat source is turned off to end the test of the sample.
(7) The critical heat flow density (CHF) and boiling heat exchange coefficient (HTC) of different porous structures are calculated through thermocouple test and formulas (1) and (2).
(1)
(2)
Is the heat flux density, W/m 2 K is the metal heat conductivity coefficient, W/(m.K),>is the temperature difference, DEG C, & gt>Distance, m, & gt>Is the heat exchange coefficient, W/(m) 2 ·K），/>The temperature of the wall surface is °c +.>Is liquid saturation temperature and DEG C;
the test results are shown in the following table:
it is known that: saturation temperature T of deionized water under normal atmospheric pressure sat Copper thermal conductivity k= 386.4W/(m·k) =100 ℃, Δδ=5 mm
The results of critical heat flux density (CHF) and boiling Heat Transfer Coefficient (HTC) for the different porous structures are shown in fig. 10, from which it can be seen that as the superheat increases, the heat flux density gradually increases to 63.5W/m 2 to reach the critical heat flux density. Meanwhile, the heat exchange coefficient gradually increases along with the increase of the heat flux density, and starts to decrease after reaching a maximum value.
Claims (9)
1. The enhanced boiling heat transfer experimental device based on capillary force is characterized by comprising a serpentine condenser tube, a digital display pressure gauge, an auxiliary heating rod, a condensing cover plate (2), an evaporation cavity (1), an evaporation base (4), an evaporation base cover plate (5), a separable heating block and a rotary bracket (3),
the evaporation cavity (1) comprises a front observation window (8), a right observation window (9), a left observation window (16) and a cavity body, wherein the cavity body is a cube with an opening at the top end, a periphery and a closed bottom end, the right observation window (9) and the left observation window (16) are oppositely arranged on two side surfaces of the cavity body, the front observation window (8) is arranged on the remaining one side surface of the cavity body, an evaporation base mounting square opening (13), an auxiliary heating rod mounting hole (10) and a drainage threaded hole (11) are arranged on the remaining other side surface of the cavity body, the evaporation base mounting square opening (13) is arranged on the upper portion of the remaining other side surface of the cavity body, the auxiliary heating rod mounting hole (10) and the drainage threaded hole (11) are sequentially arranged at the bottom of the evaporation base mounting square opening (13), the auxiliary heating rod mounting hole (10) is used for connecting an auxiliary heating rod, and the drainage threaded hole (11) are movably and hermetically connected for drainage;
The condensing cover plate (2) is arranged above the evaporating cavity (1) and is movably and hermetically connected with the evaporating cavity (1), and comprises a cover plate body, a reducing branch pipe (19), an adding liquid opening (20) and a digital display pressure gauge mounting threaded hole (22), wherein the reducing branch pipe (19), the adding liquid opening (20) and the digital display pressure gauge mounting threaded hole (22) are arranged on the upper surface of the cover plate body and penetrate through the cover plate body, the digital display pressure gauge mounting threaded hole (22) is used for connecting a digital display pressure gauge, one end of a steam condensing part of a serpentine condensing pipe is connected with the reducing branch pipe (19) in a nested manner, the other end of the steam condensing part of the serpentine condensing pipe is used for connecting a vacuumizing system, a water inlet and outlet of the serpentine condensing pipe is connected with a low-temperature constant temperature tank and used for condensing steam, and the adding liquid opening (20) is used for adding working liquid;
the rotary support (3) is used for supporting the evaporation cavity (1) and comprises a support panel and a rotary structure arranged at the bottom of the support panel, and the evaporation cavity (1) is arranged at the top end of the support panel when the experimental device is used;
the evaporation base apron (5) is connected with evaporation cavity (1) through evaporation base (4), evaporation base (4) is inside to correspond boss hollow boss piece, including protruding part and boss main part, protruding part is through evaporation base installation square trompil (13) and evaporation cavity (1) scarf joint, the boss main part is close to the one side of protruding part and evaporation cavity (1) surface contact, the one side of protruding part is kept away from to evaporation base apron (5) locates the boss main part, detachable heating piece locates evaporation base (4) inside hollow, and detachable heating piece one end stretches into evaporation cavity (1) for heating the sample, the other end is connected with the heating source.
2. The enhanced boiling heat transfer experimental device based on capillary force as claimed in claim 1, wherein the separable heating block comprises a separable heating block upper part (6) and a separable heating block lower part (7), the separable heating block upper part mounting hole (24) and the separable heating block lower part mounting hole (26) are arranged on the evaporation base (4), the separable heating block upper part mounting hole (24) is annularly arranged at the middle front end of the boss corresponding to the boss shape in the boss part and is used for mounting the upper part of the separable heating block upper part (6), the separable heating block lower part mounting hole (26) is hollow of the boss corresponding to the boss shape in the boss main body and is used for mounting the lower part of the separable heating block lower part (7), the separable heating block upper part (6) comprises a square block, a cylinder arranged at the bottom center of the square block, a sample sintering surface (27) and a bottom threaded hole (29), the sample sintering surface (27) is arranged at the top of the square block and is used for testing samples, and the bottom threaded hole (29) is arranged at the bottom of the cylinder;
the utility model provides a down (7) of disconnect-type heating block includes square main part, nested hole (30) and through-hole (31), and square main part is just not penetrated in square main part center is located in nested hole (30) center to nested hole (30), and pierces through square main part, and nested hole (30) are used for on the nested disconnect-type heating block (6) cylinder bottom, and square main part is connected with the heating source, and on (7) and the disconnect-type heating block down (6) pass through-hole (31) and bottom screw hole (29) cooperation fixed connection through the bolt.
3. The enhanced boiling heat transfer experimental device based on capillary force as claimed in claim 1, wherein the condensation cover plate (2) and the evaporation cavity (1) are movably and hermetically connected through a bolt a, wherein a plurality of evaporation cavities with internal threads matched with the outer surface of the bolt a and condensation cover plate connecting through holes (18) are arranged at the top end of the evaporation cavity (1), a plurality of groups of evaporation cavity connecting through holes (21) with internal threads matched with the outer surface of the thread a and corresponding to the evaporation cavities and condensation cover plate connecting through holes (18) are arranged at the bottom of the condensation cover plate (2), and the bolt a is used for connecting the evaporation cavities and the condensation cover plate connecting through holes (18) and the evaporation cavity connecting through holes (21);
the evaporation base cover plate (5) is connected with the evaporation cavity (1) through the evaporation base (4) through the bolt b, a plurality of groups of internal threads and a plurality of groups of connecting holes (33) matched with the outer surface of the bolt b are formed in the periphery of the evaporation base cover plate (5), a plurality of groups of internal threads and a plurality of groups of evaporation base fixing holes (23) matched with the outer surface of the bolt b are formed in the position corresponding to the evaporation base (4), the evaporation cavity (1) comprises a plurality of groups of internal threads and a plurality of groups of evaporation base fixing threaded holes (14) matched with the outer surface of the bolt b, the evaporation base fixing holes (14) are uniformly distributed in the periphery of the outer side of the evaporation base mounting square opening (13) and correspond to the positions of the evaporation base fixing holes (23), and the bolts b are used for connecting the connecting holes (33), the evaporation base fixing holes (23) and the evaporation base fixing threaded holes (14).
4. The capillary force-based intensified boiling heat transfer testing apparatus according to claim 1, wherein the rotating structure comprises a supporting seat, a locking bolt (34) and a rotating part, the rotating part is rotatably connected with the supporting seat through the locking bolt (34), and the supporting panel is arranged on the upper surface of the rotating part.
5. The enhanced boiling heat transfer experimental device based on capillary force as claimed in claim 1, wherein the contact surface of the condensation cover plate (2) and the evaporation cavity (1), the contact surface of the evaporation base (4) and the evaporation cavity (1) and the contact surface of the separation type heating block (6) and the evaporation base (4) are provided with sealing elements, the contact surface of the condensation cover plate (2) and the evaporation cavity (1) and the sealing elements at the contact surface of the separation type heating block (6) and the evaporation base (4) are sealing gaskets, the edge of the opening at the top end of the evaporation cavity (1) is provided with a sealing groove (17), the sealing groove (17) is used for embedding the sealing gaskets, and the sealing gaskets are made of silicon rubber, fluorine silicon rubber, nylon, polyurethane or engineering plastics.
6. The experimental device for enhancing boiling heat transfer based on capillary force as claimed in claim 2, wherein the heating source under the separate heating block (7) is a ceramic heating plate, the ceramic heating plate is attached to the periphery of the outer edge of the square main body and is connected with an external power supply through a lead wire, the separate heating block under (7) further comprises a heat preservation material, the heat preservation material is wrapped on the outer side of the ceramic heating plate, and the heat preservation material is heat preservation cotton or aerogel felt.
7. The capillary force-based intensified boiling heat transfer testing apparatus according to claim 1, further comprising a high-speed camera fixed in front of the front observation window (8) for shooting evaporation and boiling phenomena of the porous structure surface in the cavity, wherein the front observation window (8), the right observation window (9) and the left observation window (16) are transparent toughened glass, and transparent heating films are adhered to the outer sides of the transparent toughened glass for preventing atomization of the observation windows, and light sources are arranged on the two sides of the right observation window (9) and the left observation window (16) for respectively illuminating from the left or right observation windows.
8. The enhanced boiling heat transfer experimental device based on capillary force as claimed in claim 6, wherein the evaporation cavity (1) further comprises a measuring steam temperature thermocouple installation hole (15) and a measuring working medium temperature thermocouple installation threaded hole (12), the measuring steam temperature thermocouple installation hole (15) is arranged at the top of the other side surface of the cavity body, the measuring working medium temperature thermocouple installation threaded hole (12) is arranged at the bottom of the evaporation base installation square opening (13), the measuring working medium temperature thermocouple installation threaded hole (12) is used for connecting with a measuring working medium temperature thermocouple, the measuring steam temperature thermocouple installation hole (15) is used for connecting with a measuring steam temperature thermocouple, and the measuring working medium temperature thermocouple and the measuring steam temperature thermocouple are connected with the data acquisition module through leads;
The split type heating block (6) further comprises three thermocouples and three equidistant thermocouple mounting holes (28) corresponding to the thermocouples, the three equidistant thermocouple mounting holes (28) are equidistantly arranged on the axial outer surface of the cylinder and used for mounting the three thermocouples, and the three thermocouples are connected with the data acquisition module through leads;
the evaporation base cover plate (5) further comprises a thermocouple and ceramic heating plate line opening (32) arranged in the center of the evaporation base cover plate (5) and used for leading wires through the thermocouple and the ceramic heating plate;
a thermocouple circuit fixing groove (25) is formed in the hollow part of the inside of the evaporation base (4), and the thermocouple circuit fixing groove (25) is used for fixing leads connected with three thermocouples;
the intensified boiling heat transfer experimental device based on capillary force also comprises a data acquisition module, wherein the input end of the data acquisition module is respectively connected with the data output ends of the three thermocouples on the measuring working medium temperature thermocouple, the measuring steam temperature thermocouple and the heating block.
9. The capillary force based enhanced boiling heat transfer assay device of claim 1, wherein said sample is a wick structure comprising at least one of a multi-layered copper mesh sintering, a metal foam, a machined channel, and a chemically modified surface.
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| CN202321095319.8U CN219978172U (en) | 2023-05-09 | 2023-05-09 | Enhanced boiling heat transfer experimental device based on capillary force |
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