Background
The heat pipe is a high-performance heat transfer element, and the heat conductivity of the heat pipe is tens of times or even hundreds of times of that of copper with the same size. The heat pipe extends the degree direction, and the heat pipe divide into evaporation zone, adiabatic section and condensation segment, and its theory of operation is: the working medium is heated and vaporized in the evaporation section, the steam pressure of the evaporation section is increased, the steam flows to the condensation section under the action of small pressure difference, the steam is condensed into liquid by releasing heat in the condensation section, the liquid working medium returns to the evaporation section through the capillary action of the capillary core to form circulation, and the heat of the evaporation section is continuously transmitted to the condensation section, so that the temperature of the evaporation section is reduced.
The capillary core is a core component of the heat pipe, and the performance of the capillary core is directly determined by the performance of the heat pipe. The capillary core provides a continuous power, namely capillary force, for the condensate to flow back to the evaporation section, and the magnitude of the capillary force depends on the size of a meniscus formed by a gas-liquid interface, and generally, the smaller the radius of the meniscus, the larger the capillary force, and conversely, the smaller the capillary force. However, the capillary core with larger capillary force has smaller effective aperture, so the permeability of the working medium is lower, thereby reducing the heat transfer capacity of the heat pipe. How to balance the contradiction of capillary force and permeability plays a significant role in the heat transfer performance of the heat pipe.
The role of the wick in the heat pipe is self-evident, but there are few means for testing the performance of the wick. For example, the capillary wick testing apparatus and method disclosed in CN201010188608.3 and CN201510821943.5 are all methods that basically process the whole heat pipe or the whole evaporator, and combine with an external heat source and related equipment to deduce the related performance of the capillary wick by studying external parameters. The device and the method disclosed in patent CN201810238721.4 utilize the capillary wick to continuously transfer the working medium from the working medium container to the evaporation section for evaporation, and the performance of the capillary wick is estimated by measuring the weight of the working medium container.
Objectively, the above-mentioned several solutions can bring out their respective technical effects described in the technical effect column of the specification, but have the following disadvantages: firstly, the capillary core test equipment is either complex and has high test cost or simple structure, and cannot completely simulate the real environment inside the heat pipe; secondly, the device designed by the scheme can only test one capillary core, has one angle and relatively single function; thirdly, the device designed by the scheme can not realize visualization and can not clearly observe the capillary action process of the capillary core.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a heat pipe wick testing apparatus, which can truly reflect the internal environment of a heat pipe, and realize multi-angle measurement and observation of the performance of a wick.
In order to achieve the purpose, the invention adopts the following technical scheme: the heat pipe capillary core testing device comprises a testing box body, wherein a condenser is arranged on the side surface of the testing box body, a third observation window is arranged at the first end of the testing box body, a first flange is arranged at the second end of the testing box body, a heating structure and a working medium inlet are arranged on the first flange, and a first observation window, a second observation window and a working medium outlet used for discharging the working medium are further arranged on the side surface of the testing box body.
Compared with the prior art, the invention has the following advantages:
(1) the heat pipe capillary core testing device can test the capillary core of the heat pipe at low temperature, normal temperature and high temperature;
(2) the heat pipe capillary core testing device can test the capillary performance of the capillary core and can also be used for observing the condensation phenomenon;
(3) in the heat pipe capillary core testing device, the visual observation windows are arranged at the front end and the side surface of the testing box body, so that the observation field is larger, the light in the cavity is improved, and the visual observation is facilitated;
(4) in the heat pipe capillary core testing device, the tested capillary core can be adjusted and rotated at will within a certain angle range, so that the testing range is wider;
(5) the heat pipe capillary core testing device adopts a modular design, and each part can be independently changed in design according to requirements.
Drawings
Fig. 1 is a schematic view of the overall structure of a heat pipe wick testing device according to the present invention.
Fig. 2 is a schematic partial structure diagram of a heat pipe wick testing apparatus according to the present invention.
Fig. 3 is a cross-sectional view of a heat pipe wick testing apparatus of the present invention.
Fig. 4 is a cross-sectional view of a heating structure in a heat pipe wick testing apparatus of the present invention.
Fig. 5 is a cross-sectional view of a third observation window of a heat pipe wick testing apparatus of the present invention.
Wherein the reference numerals explain: 1-test box body, 2-first end, 3-second end, 4-heating structure, 5-first flange, 6-second flange, 11-condenser, 111-cooling medium cavity, 112-cooling medium inlet, 113-cooling medium outlet, 12-first observation window, 121-first glass, 122-first sealing plate, 13-working medium outlet, 14-second observation window, 141-second glass, 142-second sealing plate, 21-third observation window, 211-third glass, 212-front cover, 213-sealing ring, 214-heat preservation cover, 41-heat transfer rod, 42-heating rod, 43-bulb tube, 44-ceramic heat insulation piece, 45-sleeve, 46-ceramic top cover, 47-end cover, 48-nut, 49-capillary fixed plate, 51-working medium inlet, 52-mounting hole, 53-temperature measuring hole and 54-preformed hole.
Detailed Description
In order to clearly understand the technical spirit and the advantages of the present invention, the applicant makes the following detailed description by way of examples, but the description of the examples is not intended to limit the technical scope of the present invention, and any equivalent changes made according to the present inventive concept, which are merely in form and not in material, should be considered as the technical scope of the present invention.
Referring to fig. 1, the heat pipe capillary core testing device of the present invention is a sealing structure, and includes a testing box 1, a condenser 11 is disposed on a side surface of the testing box 1, a third observation window 21 capable of observing the working condition inside the testing box 1 is disposed on a first end 2 of the testing box 1, a first flange 5 is disposed on a second end 3 of the testing box 1, a heating structure 4 and a working medium introducing port 51 are disposed on the first flange 5, and a first observation window 12 and a second observation window 14 capable of observing the working condition inside the testing box 1, and a working medium leading-out port 13 for removing the working medium are further disposed on a side surface of the testing box 1.
Referring to fig. 4, in a preferred embodiment of the present invention, the heating structure 4 includes a heat transfer rod 41, a heating rod 42, a bulb tube 43, a ceramic heat insulating member 44, a sleeve 45, a ceramic top cover 46, a nut 48, and a capillary fixing plate 49, the heating rod 42 is disposed in the sleeve 45 and disposed on a first end of the heat transfer rod 41, the sleeve 45 is disposed in the bulb tube 43, a second end of the heat transfer rod 41 is disposed with a capillary core fixing plate 49, the capillary core fixing plate 49 is disposed outside the bulb tube 43, a first end of the sleeve 45 is disposed with the ceramic top cover 46, the ceramic top cover 46 passes through a central hole of an end cover 47 on the first end of the bulb tube 43 and is connected to the nut 48 disposed on the central hole, the sleeve 45 is driven by the nut 48 to move axially, thereby driving the capillary core fixing plate 49 to move axially, for heat insulation, the ceramic heat insulating member 44 unconnected to the heating rod 42 is further disposed in the sleeve 45, the ceramic thermal shield 44 is in contact with but not secured to the ceramic top cap 46.
Referring to fig. 3, in a preferred embodiment of the present invention, the first flange 5 is provided with a mounting hole 52, a temperature measuring hole 53 and a reserved hole 54, the heating structure 4 passes through the mounting hole 52, one end of the heating structure is arranged outside the testing box 1, the other end of the heating structure is arranged inside the testing box 1, the temperature measuring hole 53 is used for installing a temperature measuring thermocouple later to measure the temperature of the liquid working medium filled therein, and the reserved hole 54 is a spare hole.
Referring to fig. 3, in a more preferred embodiment of the present invention, the bulb tube 43 of the heating structure 4 passes through the mounting hole 52, a first end of the bulb tube 43 is disposed outside the test chamber body 1, and a second end of the bulb tube 43 is disposed inside the test chamber body 1.
Referring to fig. 3, in a more preferred embodiment of the present invention, a second flange 6 is provided on the second end of the bulb tube 43 of the heating structure 4, and the heating structure 4 is fixed to the first flange 5 by the second flange 6.
In a more preferred embodiment of the invention, a sealing ring is provided between the second end of the bulb tube 43 and the second flange 6.
In a preferred embodiment of the present invention, the angle between the condenser 11 and the normal line of the working medium outlet 13 is 180 °, the angle between the condenser 11 and the first observation window 12 is 30 ° to 50 °, and the angle between the first observation window 12 and the second observation window 14 is 90 °.
Referring to fig. 2, in a preferred embodiment of the present invention, the condenser 11 has a cooling medium chamber 111 therein, a cooling medium inlet 112 is provided at a side of the condenser 11, a cooling medium outlet 113 is provided at a top thereof, and the cooling medium inlet 112 and the cooling medium outlet 113 are communicated with the cooling medium chamber 111 and connected to a cooling medium circulation supply device.
Referring to fig. 2 and 5, in a preferred embodiment of the present invention, the third observation window 21 includes a third glass 211, a front cover 212, a sealing ring 213 and an insulation cover 214, through holes are formed in both the front cover 212 and the insulation cover 214, the front cover 212 and the insulation cover 214 are connected to form a structure having a cavity therein and a center of the through hole, the third glass 211 is disposed on the through hole of the front cover 212, a first end of the sealing ring 213 is connected to the third glass 211, a second end of the sealing ring 213 passes through the through hole of the insulation cover 214 and is flush with the insulation cover 214, for easy installation and disassembly, a gap is left between the second end of the sealing ring 213 and the through hole of the insulation cover 214 (i.e., the second end of the sealing ring 213 is not connected to the insulation cover 214), and for achieving the insulation effect, the cavity between the insulation cover 214 and the front cover 212 needs to be filled with an insulation material.
Referring to fig. 2, in a preferred embodiment of the present invention, the first observation window 12 is composed of a first glass 121 and a first sealing plate 122, a through hole is formed in the first sealing plate 122, and the first glass 121 is disposed on the through hole.
Referring to fig. 2, in a preferred embodiment of the present invention, the second observation window 14 is composed of a second glass 141 and a second sealing plate 142, a through hole is formed on the second sealing plate 142, and the first glass 141 is disposed on the through hole.
In a preferred embodiment of the present invention, the capillary fixing plate 49 is provided with a capillary core, and the capillary fixing plate 49 is made of red copper.
In a preferred embodiment of the present invention, the nut 48 is a swivel nut.
In a preferred embodiment of the invention, the distance between the heating structure 4 and the working substance inlet 51 is 50 to 100 mm.
In a preferred embodiment of the present invention, the heating structure 4 is disposed at a position of 0 to 1/3r from the center of the first flange 5, r being the radius of the first flange 5.
With reference to fig. 1 to 5, professional operators check the tightness of the device of the present invention, and then vacuumize the device through the working medium introducing port 51, and after the vacuumization is finished, the liquid working medium enters the inner cavity of the testing box 1 through the working medium introducing port 51. The capillary core is fixed on a capillary core fixing plate 49 of the heating structure 4, and one end of the capillary core is immersed in the liquid working medium. A certain amount of the condensed medium is introduced into the cooling medium chamber 111 from the cooling medium introducing port 112 provided on the side surface of the condenser 11 by the cooling medium circulation supply means to be circulated and cooled. The power supply is controlled by the control system to heat the heating rod 42 of the heating structure 4 to a desired temperature or heat flux density. After the heating rod 42 is heated, the heat is transferred to the second end of the heat transfer rod 41 through the first end of the heat transfer rod 41, and the second end of the heat transfer rod 41 transfers the heat to the capillary fixing plate 49 again, so that the capillary core is heated. Due to the capillary action of the capillary core, the liquid working medium continuously flows upwards through the capillary core, reaches the other end of the capillary core fixing plate 49 and is evaporated into steam, the steam flows upwards into the condenser 11, becomes liquid under the condensation action of the condenser 11, flows back into the test box body 1 along the inner wall, and the steps are repeated in a circulating mode. The related performance of the tested capillary wick is recorded through the first observation window 12, the second observation window 14 and the third observation window 21, the third observation window 21 is arranged opposite to the heating structure 4, so that the working condition of the capillary wick on the capillary wick fixing plate 49 can be observed very clearly, the second observation window 14 and the third observation window 21 are arranged on the side surface of the test box body 1, in order to prevent the condenser 11 from obstructing the observation sight line of the first observation window 12, the first observation window 12 and the condenser 11 are arranged at an angle of 30-50 degrees, and in order to observe the working condition in the test box body 1 more clearly and omnidirectionally, the first observation window 12 and the second observation window 14 are arranged at an angle of 90 degrees. During observation, the nut 48 of the heating structure 4 can be adjusted to move the sleeve 45 back and forth, so as to drive the capillary wick fixed on the capillary fixing plate 49 to move back and forth, and the nut 48 can also rotate the sleeve 45, so as to adjust the angle of the capillary wick fixed on the capillary fixing plate 49, thereby finding the best observation position.