CN113329524A

CN113329524A - Wave-permeable heating film

Info

Publication number: CN113329524A
Application number: CN202110699787.5A
Authority: CN
Inventors: 陈华伟; 朱彦瞳; 刘晓林; 赵泽辉; 王泽林澜; 陈济琛
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2021-08-31

Abstract

The present application relates to the field of heating devices, in particular to a wave-permeable heating film, in particular to a wave-permeable heating film, which includes a microfluidic membrane and a microfluidic channel disposed in the microfluidic membrane , the two ends of the microfluidic channel penetrate to the outside of the microfluidic channel membrane, the microfluidic channel is installed with a pair of interfaces that can conduct electricity and pass liquid at the same time, and the two ends of the microfluidic channel are respectively connected with a pusher through the interface, so The pusher includes a first microfluidic thruster and a second microfluidic thruster respectively connected to two interfaces, the first microfluidic thruster is filled with a conductive material that can fill the entire microfluidic channel. liquid metal. The heating film can be switched between conductive heating and non-conductive wave-transmitting states, and the present application has the effect of enabling the heating film to have both heating and wave-transmitting functions.

Description

Wave-permeable heating film

Technical Field

The application relates to the field of heating devices, in particular to a wave-permeable heating film.

Background

The heating film technology is widely applied to various fields, such as heat preservation and heating of equipment or space, anti-icing/deicing of surfaces of equipment such as airplanes and the like.

Various heating films are basically provided with heating resistors in the heating films, and based on the principle of Joule's law, the electric heating film based on the principle requires the electric heating film to have good conductive performance by applying a power supply with certain power to the heating resistors. Some equipment surfaces not only have heating requirements but also wave-transparent requirements, for example, the surfaces of aircrafts often have stealth requirements, and the main principle of stealth aircrafts is as follows: when the radar transmits rays to continuously detect the aircraft, the aircraft is made of wave-transmitting materials, so that the rays transmitted by the radar can penetrate through the aircraft, the radar cannot detect the existence of the aircraft, and the surface of the aircraft with stealth requirements has wave-transmitting requirements.

The traditional heating film has good conductivity, so that the reflection capability of the traditional heating film to electromagnetic waves is strong, and the traditional heating film is not beneficial to being used on the surface of equipment with wave-transmitting requirements, so that the traditional heating film cannot realize the functions of compatible heating and wave-transmitting.

Disclosure of Invention

In order to enable the heating film to have the functions of heating and wave-transmitting, the application provides a wave-transmitting heating film.

The wave-permeable heating film adopts the following technical scheme:

the utility model provides a heating film of permeable ripples, includes the miniflow way membrane and sets up the miniflow way in the miniflow way membrane, and the both ends of miniflow way extend to the miniflow way membrane outside, install the interface that a pair of conductibility can lead to liquid simultaneously in the miniflow way, the both ends of miniflow way are connected with a propeller respectively through the interface, the propeller includes first miniflow way propeller and the second miniflow way propeller with two interface connection respectively, it has the liquid metal that can electrically conduct that can be full of whole miniflow way to fill in the first miniflow way propeller.

By adopting the technical scheme, the aim of heating the heating film by using the electrode is achieved by using the liquid metal to fill in the micro-channel, the liquid metal can move freely in the micro-channel, when the heating function of the heating film is not needed, the liquid metal in the micro-channel is pumped out from the micro-channel by the first micro-channel propeller, the liquid metal flows into the first micro-channel propeller, the liquid metal does not fill in the micro-channel, the whole micro-channel film can have a better wave transmission function to realize the stealth function of the aircraft, when the heating function of the heating film is needed to be reused, the liquid metal is pushed into the micro-channel by using the first micro-channel propeller, two ends of the liquid metal flow to positions in contact with the two electrodes, the two electrodes pressurize the liquid metal, and the liquid metal is heated, the heating function of the heating film is realized, and the heating film can be switched between a conductive heating state and a non-conductive wave-transmitting state.

Optionally, the second micro-channel propeller is filled with immiscible liquid which is immiscible with the liquid metal, and the immiscible liquid has wave-transmitting characteristics.

Through adopting above-mentioned technical scheme, fill immiscible liquid in second microchannel propeller, when the function that does not need to use microchannel membrane conductive heating, second microchannel propeller impels immiscible liquid to inject into the microchannel from the one end of keeping away from first microchannel propeller, liquid metal in the microchannel is promoted in first microchannel syringe, at this moment, there is not the air in the microchannel to fill, the effectual interference that has reduced because the air produces whole heating film wave permeability.

Optionally, the relative dielectric constants of the micro flow channel film and the immiscible liquid are both less than 2.8.

Optionally, the difference between the relative dielectric constants of the micro flow channel film and the immiscible liquid is less than 0.5.

By adopting the technical scheme, the material of the micro-channel membrane is close to the dielectric constant of the immiscible liquid, so that the reflected wave caused by the difference of the dielectric constants between the micro-channel membrane and the immiscible liquid when the immiscible liquid is filled in the micro-channel is reduced, and the wave transmission performance of the whole heating film is better.

Optionally, the micro flow channel film is made of a polymer of a low dielectric constant nonpolar material.

By adopting the technical scheme, the micro-channel film with low dielectric constant can ensure that the whole micro-channel film has better wave-transmitting performance.

Optionally, the immiscible liquid has a room temperature kinematic viscosity of less than 200 square millimeters per second and a freezing point of less than-20 ℃.

Through adopting above-mentioned technical scheme, the mobility of immiscible liquid is good, and the resistance when making immiscible liquid flow in the miniflow channel is less, and immiscible liquid gets the freezing point low, can effectually avoid the freezing phenomenon of immiscible liquid under the low temperature condition to solidify to keep whole heating film's function to switch.

Optionally, the interface includes a first electrode plate and a second electrode plate for powering on, a first flow channel is fixed on a surface of the first electrode plate close to the second electrode plate, a second flow channel is fixed on a surface of the second electrode plate close to the first electrode plate, an outer diameter of the first flow channel is equal to an inner diameter of the second flow channel, and the first flow channel is inserted inside the second flow channel and forms an interference fit.

By adopting the technical scheme, the outer diameter of the first flow channel is equal to the inner diameter of the second flow channel, so that the first flow channel and the second flow channel are in interference fit after being spliced, and liquid in the micro-flow channel flows in and out through the interface, thereby ensuring stable internal pressure of the micro-flow channel and smooth flowing of the liquid in the micro-flow channel.

Optionally, the interface includes a first opening disposed on one side of the first flow channel, and the second electrode plate is provided with a third opening.

By adopting the technical scheme, the liquid in the micro-channel can be ensured to flow in and out through the first opening and the third opening, and the flowing channel of the liquid is single, so that the possibility that the liquid flows out from other openings is reduced.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the aim of heating the heating film by using the electrode is achieved by using a mode that liquid metal is filled in the micro-channel, and the liquid metal can move freely in the micro-channel; when the heating function of the heating film is not needed, the liquid metal in the micro-channel is extracted from the micro-channel through the first micro-channel propeller, the liquid metal flows into the first micro-channel propeller, and the micro-channel is not filled with the liquid metal, so that the whole micro-channel film can have a good wave-transmitting function, and the stealth function of the aircraft is realized; when the heating function of the heating film needs to be used again, the first micro-channel propeller is used for pushing the liquid metal into the micro-channel, two ends of the liquid metal flow to positions in contact with the two electrodes, the two electrodes pressurize the liquid metal, and the liquid metal is heated to raise the temperature, so that the heating function of the heating film is realized, and the heating film can be switched between a conductive heating state and a non-conductive wave-transmitting state;

2. the immiscible liquid is filled in the second micro-channel propeller, when the function of micro-channel membrane conductive heating is not needed, the immiscible liquid is pushed into the micro-channel from one end far away from the first micro-channel propeller by the second micro-channel propeller, the liquid metal in the micro-channel is pushed into the first micro-channel injector, at the moment, no air is filled in the micro-channel, and the interference of the air on the wave permeability of the whole heating film is effectively reduced.

Drawings

Fig. 1 is a schematic overall structure diagram of an embodiment of the present application.

Fig. 2 is an exploded view of an interface in an embodiment of the present application.

Fig. 3 is a schematic structural diagram of an interface in the embodiment of the present application.

Fig. 4 is a schematic view of an alternative embodiment of the pusher in state two of the present application.

Fig. 5 is a schematic view of an alternative propulsion member in the embodiment of the present application in a state one.

Fig. 6 is a block diagram showing a structure of a part of the device mounted on the liquid pipe in the embodiment of the present application.

Description of reference numerals: 1. a micro flow channel membrane; 2. a micro flow channel; 3. an interface; 31. a first metal interface; 311. a first electrode plate; 312. a first flow passage; 3121. a first opening; 32. a second metal interface; 321. a second electrode plate; 3211. a third opening; 322. a second flow passage; 3221. a second opening; 4. a pusher member; 41. a first microchannel propeller; 42. a second microchannel propeller; 6. a liquid metal; 7. an immiscible liquid; 8. a liquid conduit; 81. a one-way throttle valve; 82. a liquid driving member; 83. a pressure reducing valve.

Detailed Description

The present application is described in further detail below with reference to figures 1-6.

The embodiment of the application discloses a heating film capable of transmitting waves. Referring to fig. 1, the heating thin film includes a micro flow channel film 1 and a micro flow channel 2 provided in the micro flow channel film 1; the first end and the tail end of the micro-channel 2 are respectively provided with one interface 3, liquid is filled in the micro-channel 2, the two interfaces 3 of the micro-channel 2 are respectively connected with one propelling part 4, and the propelling part 4 comprises a first micro-channel propeller 41 and a second micro-channel propeller 42.

The micro flow channel 2 is bent and spirally arranged in the micro flow channel film 1, in the embodiment, the micro flow channel film 1 is a membrane of a polymer matrix, the polymer matrix material can be selected from low dielectric constant nonpolar materials such as polydimethylsiloxane, polyacetamide, polyether ether ketone, styrene butadiene rubber, epoxy resin, polyurethane and the like, and the low dielectric constant material can ensure the wave transmission performance of the whole heating film.

The cross section of the micro flow channel 2 can be selected from a circle with the diameter of 1-2mm or a square with the side length of 1-2mm, the thickness of the whole heating film is occupied to a small extent under the condition of not influencing the liquid flow, and the manufacturing method of the micro flow channel 2 can adopt methods such as mold repeated engraving forming, laser engraving processing, impression forming and the like.

Referring to fig. 2, the interface 3 includes a first metal interface 31 and a second metal interface 32, and the first metal interface 31 includes a first electrode plate 311 and a first flow channel 312 fixed to the first electrode plate 311. The first electrode plate 311 is disc-shaped, the first flow channel 312 is tubular with two open ends, and the annular side surface of the first flow channel 312 is provided with a first opening 3121.

The second metal interface 32 includes a second electrode plate 321 having a disk shape and a second flow channel 322 fixed to the second electrode plate 321. The second flow channel 322 is also tubular with two open ends, and the side of the second flow channel 322 is provided with a second opening 3221. The second electrode plate 321 is provided with a third opening 3211, and the third opening 3211 is communicated with the second flow channel 322. The material of the first electrode plate 311 and the second electrode plate 321 includes, but is not limited to, copper, aluminum, and other alloy conductive materials.

Referring to fig. 2 and 3, the outer diameter of the first flow channel 312 is equal to the inner diameter of the second flow channel 322, the first flow channel 312 is inserted inside the second flow channel 322, so that the first flow channel 312 and the second flow channel 322 are in interference fit, the first opening 3121 is communicated with the second opening 3221, and each interface 3 is provided with two openings for liquid to flow.

In use, liquid in the microchannel 2 flows along the first and

third openings

3121 and 3211. The first flow channel 312 and the second flow channel 322 are partially in interference fit, so that the internal pressure of the micro flow channel 2 is stable and the internal liquid flows smoothly.

Referring to fig. 1 and 3, a conductive wire is further connected between the two interfaces 3, and a power supply for applying voltage is connected to the conductive wire, and the first electrode plate 311 or the second electrode plate 321 of each interface 3 is connected to the conductive wire and is electrically conducted by the first electrode plate 311 or the second electrode plate 321.

Referring to fig. 1, the first micro flow channel propeller 41 is filled with liquid metal 6 or immiscible liquid 7, the second micro flow channel propeller 42 is filled with liquid metal 6 or immiscible liquid 7, and the liquids filled in the first micro flow channel propeller 41 and the second micro flow channel propeller 42 are different. The immiscible liquid 7 cannot be dissolved in the liquid metal 6, the liquid metal 6 and the immiscible liquid 7 are respectively filled into the micro flow channel 2 through the two interfaces 3, and the whole micro flow channel 2 can be filled with the volume of the liquid metal 6 or the immiscible liquid 7.

Referring to fig. 1 and 4, the first microchannel propeller 41 and the second microchannel propeller 42 may be various types of syringes, injection pumps, etc., and since one of the first microchannel propeller 41 and the second microchannel propeller 42 is pushed out while the other is pushed out, the first microchannel propeller 41 and the second microchannel propeller 42 always perform reverse motions in synchronization, or may be linked by using a synchronous driving device.

Referring to fig. 1, the liquid metal 6 in this embodiment is a material having a low melting point (i.e., melting point is 10 ℃ or less, i.e., freezing point, and if the melting point is too high and the normal temperature is solid, it cannot flow (the general anti-icing temperature is 20 ℃ or less)) and can freely flow in the micro flow channel 2, for example: alloys of metals such as gallium, indium, and tin can directly generate joule heat after direct current or alternating current is applied.

The immiscible liquid 7 in this embodiment may be selected from liquids immiscible with the liquid metal 6, such as methyl silicone oil, amino silicone oil, liquid paraffin, low melting point lubricating liquid, and the like, and meanwhile, the immiscible liquid 7 is nonconductive, and the room temperature kinematic viscosity of the immiscible liquid is less than 200 square millimeters per second, and the freezing point is lower than-20 ℃.

When the immiscible liquid 7 and the polymer matrix for manufacturing the micro flow channel membrane 1 are selected, the dielectric constants of the immiscible liquid 7 and the polymer matrix are measured and investigated, the relative dielectric constant of the immiscible liquid 7 and the polymer matrix is less than 2.8, and when the difference between the relative dielectric constant and the relative dielectric constant is less than 0.5, the interference of the micro flow channel membrane 1 and the immiscible liquid 7 meeting the condition on electromagnetic waves is minimum. Therefore, reflected waves caused by the difference of the dielectric constants of the micro-channel 2 and the immiscible liquid 7 in the second state can be reduced, and the wave permeability of the whole heating film is optimal (dimethyl silicone oil and polydimethylsiloxane are adopted in experiments, and the dielectric constants of the liquid and the polymer matrix are close to the optimal dielectric constant).

Referring to fig. 5, when the pushing member 4 pushes the liquid metal 6 to fill the micro flow channel 2, the state is defined as a state one in this embodiment, the liquid metal 6, the two ports 3 and the wires form a passage, and at this time, the wires are powered on, due to the good conductive performance of the liquid metal 6, the liquid metal 6 is conducted, the liquid metal 6 is heated by the two electrodes, and the heating film is in a heating state.

Referring to fig. 4, when the micro flow channel 2 is filled with the immiscible liquid 7, this state is defined as an initial state (also referred to as state two), and at this time, since the immiscible liquid 7 is not conductive, the immiscible liquid 7, the two interfaces 3, and the wires cannot form a passage, and then the heating film cannot be heated, so that the heating film is in a wave-transparent state.

In the initial state, the micro-channel 2 is filled with immiscible liquid 7, and at the moment, the liquid in the micro-channel 2 is not conductive and can not be heated, but the wave-transmitting performance is good, and the stealth requirement of the aircraft can be met.

Referring to fig. 5, in a first state, the pushing member 4 pushes the liquid metal 6 into the micro flow channel 2, and meanwhile, the immiscible liquid 7 is pushed out by the liquid metal 6 in the micro flow channel 2 until the liquid metal 6 fills the whole micro flow channel 2, the interfaces 3 at two ends of the micro flow channel 2 are communicated, and the liquid metal 6 generates joule heat after being connected with direct current or alternating current, at this time, the heating film has good electrical conductivity and poor wave-transparent performance.

Referring to fig. 4, on the contrary, in the second state, the pushing member 4 pushes the immiscible liquid 7 into the micro flow channel 2, and simultaneously the liquid metal 6 is pushed out until the immiscible liquid 7 fills the whole micro flow channel 2, so as to empty the liquid metal 6 in the micro flow channel 2 with the built-in electrodes, and further disconnect the conductive loop inside the micro flow channel 2. At this time, the heating film loses conductivity, but has a good wave-transmitting property. By filling or evacuating the liquid metal 6, the switching between the conductive heating performance and the insulating wave-transmitting performance of the micro-channel membrane 1 is realized, thereby realizing the controllable wave-transmitting of the heating membrane.

Referring to fig. 6, a liquid pipe 8 is provided between the first microchannel thruster 41 and one of the ports 3, and the same liquid pipe 8 is provided between the second microchannel thruster 42 and the other port 3, which will be described by taking the liquid pipe 8 connected to the first microchannel thruster 41 as an example.

The liquid pipeline 8 is provided with a one-way throttle valve 81, and the smooth switching operation of the two liquids in the micro flow channel 2 is ensured by the one-way throttle valve 81. A liquid drive 82 is also mounted on the liquid conduit 8, and the liquid in the first microchannel propeller 41 can be drawn out or withdrawn by means of the liquid drive 82, where the liquid drive 82 is a hydraulic pump.

A pressure reducing valve 83 is further installed between the one-way throttle valve 81 and the first microchannel thruster 41, and the liquid channel 8 is protected by the pressure reducing valve 83, so that the possibility of overpressure of the liquid channel 8 is reduced, and the liquid channel 8 is protected.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A wave-permeable heating film, characterized in that it comprises a microfluidic membrane (1) and a microfluidic channel (2) arranged in the microfluidic membrane (1), two of the microfluidic channel (2). The end extends to the outside of the microchannel membrane (1), the microchannel (2) is provided with a pair of interfaces (3) that can conduct electricity and can pass liquid at the same time, and the two ends of the microchannel (2) pass through the interface ( 3) A pusher (4) is respectively connected, and the pusher (4) includes a first micro-channel pusher (41) and a second micro-channel pusher (42) that are respectively connected to the two interfaces (3) ), the first micro-channel pusher (41) is filled with conductive liquid metal (6) that can fill the entire micro-channel (2).

2 . The wave-permeable heating film according to claim 1 , characterized in that: the second micro-channel propeller ( 42 ) is filled with a material that is immiscible with the liquid metal ( 6 ). 3 . The immiscible liquid (7) has a penetrating property.

3 . The wave-permeable heating film according to claim 2 , wherein the relative permittivity of the microfluidic film ( 1 ) and the immiscible liquid ( 7 ) are both less than 2.8. 4 .

4 . The wave-permeable heating film according to claim 2 , wherein the relative permittivity difference between the microfluidic film ( 1 ) and the immiscible liquid ( 7 ) is less than 0.5. 5 .

5 . The wave-permeable heating film according to claim 1 , wherein the micro-channel film ( 1 ) is a micro-channel film made of a polymer of a low dielectric constant non-polar material. 6 . (1).

6 . The wave-permeable heating film according to claim 2 , wherein the room temperature kinematic viscosity of the immiscible liquid ( 7 ) is less than 200 square millimeters per second, and the freezing point is lower than -20° C. 7 .

7 . The wave-transmitting heating film according to claim 1 , wherein the interface ( 3 ) comprises a first electrode plate ( 311 ) and a second electrode plate ( 321 ) for energization, so the A first flow channel (312) is fixed on the side of the first electrode plate (311) close to the second electrode plate (321), and a second electrode plate (321) is fixed on the side of the second electrode plate (321) close to the first electrode plate (311). A flow channel (322), the outer diameter of the first flow channel (312) is equal to the inner diameter of the second flow channel (322), and the first flow channel (312) is inserted into the inner side of the second flow channel (322) and constitutes an overpass Win cooperation.

8 . The wave-permeable heating film according to claim 7 , wherein the interface ( 3 ) comprises a first opening ( 3121 ) provided on one side of the first flow channel ( 312 ), and the first opening ( 3121 ) The second electrode plate (321) is provided with a third opening (3211).