CN214583884U - Oil-seepage induction film - Google Patents

Abstract

The application relates to an oil-seepage induction membrane, which comprises two conductive layers and an insulating layer positioned between the two conductive layers, wherein cementing layers are coated between the conductive layers and the insulating layer; at least one of the cementing layer and the insulating layer is an oil solution dissolving material or an oil solution swelling material; the conducting layer is fixedly connected with the cementing layer and is formed by at least one conducting band paved on one surface of the cementing layer; the conducting strips are laid on the gluing layer in a roundabout mode, and gaps are reserved between every two adjacent conducting strips. The method and the device have the advantages of being not easily affected by external environment, low in false alarm rate, high in sensing sensitivity and high in sensing precision.

Description

Oil-seepage induction film

Technical Field

The application relates to the field of fluid perception, especially relates to a seepage oil response membrane.

Background

Crude oil and finished oil are current important resources and have higher value. In the process of conveying crude oil or finished oil, besides the conveying structure is damaged artificially, the phenomenon of oil leakage is caused by the damage of the conveying structure due to the corrosion of acid land, air oxidation, structural aging and the like. Once the oil leaks, not only great economic loss and resource loss are caused, but also the environment is polluted. Detecting oil leaks is therefore an extremely important position in oil delivery systems.

The oil leakage detection method in the related art comprises the steps of installing a gas sensor at the periphery of an oil conveying structure; acquiring signal data generated by a gas sensor; and when the signal data exceeds the threshold value, an alarm is sent out. After the leakage of oil occurs, the gas emitted by the oil is acquired by the gas sensor, so that the signal data generated by the gas sensor changes and exceeds a threshold value, the worker receives an alarm to know that the oil leaks, and the oil is timely processed.

In view of the above-mentioned related art, the inventors consider that the oil liquid transporting structure is generally buried in soil or erected on the ground and is long in length. The environment is complex, and the sensor is easily disturbed. For example, weather, pedestrians, vehicles, animals, and the like all tend to affect the accuracy of the determination of the gas sensor, which results in a decrease in the detection accuracy of the sensor and an increase in the false alarm rate.

SUMMERY OF THE UTILITY MODEL

In order to help reducing the false alarm rate, improve fluid perception precision, this application provides a seepage oil response membrane.

The application provides a permeable to oil response membrane adopts following technical scheme:

the oil-seepage induction membrane comprises two conductive layers and an insulating layer positioned between the two conductive layers, wherein cementing layers are coated between the conductive layers and the insulating layer; at least one of the cementing layer and the insulating layer is an oil solution dissolving material or an oil solution swelling material;

the conducting layer is fixedly connected with the cementing layer and is formed by at least one conducting band paved on one surface of the cementing layer; the conducting strips are laid on the gluing layer in a roundabout mode, and gaps are reserved between every two adjacent conducting strips.

By adopting the technical scheme, the induction film is of a capacitor structure, and after the two conducting layers are connected into the same alternating current loop, electrical signal data are generated in the alternating current loop. When the oil is contacted with the cementing layer and/or the insulating layer, the cementing layer and/or the insulating layer and the oil are subjected to a dissolution or swelling reaction. Resulting in a change in the electrical signal data in the ac loop. Whether the oil leaks can be known by detecting the change of the electrical signal data. The induction film can react with oil, thereby changing the electric signal data in the alternating current loop where the induction film is located. The leakage condition of the oil liquid is directly known through the oil liquid, and the oil liquid is not easily interfered by the external environment. The false alarm rate is low, and the detection precision is higher.

Optionally, the cementing layer is an oil solution material or an oil solution swelling material; the conducting layer is formed by at least bonding conducting powder through a cementing layer.

Through adopting above-mentioned technical scheme, the cementing layer is that fluid dissolves the material or for fluid swelling material, and after fluid leaked, fluid contacted with the cementing layer. The glue layer is dissolved or swelled, so that the distance between the conductive powder in the conductive layer is increased, the resistance of the conductive layer is increased, and even the conductive layer cannot conduct electricity. When the leakage of oil liquid makes two-layer cementing layer all contact with oil liquid, the response membrane is located the electric signal data in the alternating current circuit and takes place the sudden change. At the moment, a sensing signal is generated for the staff, which is helpful for reducing the false alarm rate.

Optionally, the insulating layer is an oil solution material or an oil solution swelling material.

Through adopting above-mentioned technical scheme, insulating layer and cementing layer are the same, and when fluid leaked, insulating layer and cementing layer all took place to dissolve or swell. The change amplitude of an electric signal in an alternating current circuit where the induction film is located is increased, so that the false alarm rate is reduced, and the sensing precision is improved.

Optionally, the conductive powder includes at least one of graphite powder, aluminum powder, copper powder, silver powder, conductive carbon fiber, graphene, carbon nanotube, and ketjen black material.

Optionally, the cementing layer comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene-propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material;

the insulating layer comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material.

Optionally, one surface of the conductive layer, which is far away from the insulating layer, is provided with a protective layer, and at least one of the two protective layers is provided with a plurality of through holes for allowing oil to flow into and reach the conductive layer;

the protective layer is made of an insulating material.

By adopting the technical scheme, the liquid passes through the protective layer through the through hole to be in contact with the cementing layer and/or the insulating layer. The protective layer protects the conductive layer and the insulating layer, so that the conductive layer and the insulating layer are not easily damaged by other objects in the transportation, installation or use process of the induction film. The method is beneficial to reducing the false alarm rate and ensuring the detection precision.

Optionally, the protective layer is fixedly connected to the conductive layer; the protective layer comprises at least one of a rubber or plastic material.

By adopting the technical scheme, the protective layer has high stability and is not easy to separate from the conductive layer or the insulating layer, so that the conductive layer and the insulating layer are protected for a long time.

Optionally, the protective layer and the through holes are used for forming a capillary phenomenon with oil.

Through adopting above-mentioned technical scheme, capillary phenomenon helps promoting during fluid enters into the through-hole to contact with cementing layer and insulating layer, trigger the change of the electric signal data among the response membrane place alternating current circuit.

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

1. the response membrane is the electric capacity structure, with two conducting layers insert back in the same alternating current return circuit, generates the signal of telecommunication data in the alternating current return circuit, and the signal of telecommunication data in the alternating current return circuit changes because of the response membrane after fluid and cementing layer or insulating layer contact, and the response membrane can react with fluid to change the signal of telecommunication data in the alternating current return circuit that self was located. The leakage condition of the oil liquid is directly known through the oil liquid, and the oil liquid is not easily interfered by the external environment. The false alarm rate is low, and the detection precision is higher;

2. the cementing layer and the insulating layer are both oil solution materials or oil solution swelling materials, after oil leaks, the cementing layer and the insulating layer are in contact with the film capacitor and are dissolved or swelled, so that the electric signals in an alternating current loop where the film capacitor is located are mutated, the required oil solution amount is reduced, and the sensitivity is improved.

Drawings

FIG. 1 is a block diagram of a method of oil bleed perception;

FIG. 2 is a sectional view of a film capacitor in an oil bleeding sensing method;

FIG. 3 is a schematic view of the overall structure of the sensing film;

FIG. 4 is a schematic view of another overall structure of the sensing film;

fig. 5 is a schematic view of another overall structure of the sensing film.

Description of reference numerals: 1. a conductive layer; 2. an insulating layer; 3. a gap; 4. a protective layer; 41. and a through hole.

Detailed Description

The present application is described in further detail below with reference to figures 1-5.

The capillary phenomenon refers to a phenomenon in which the wetting liquid rises in the tubule and a phenomenon in which the non-wetting liquid falls in the tubule. For example, a small glass tube is inserted into water and the water rises to a certain height in the tube before stopping. At this time, the water level in the pipe is higher than the water level outside the pipe. For example, when a small glass tube is inserted into mercury, the mercury drops to a certain height in the tube, which is also a capillary phenomenon.

A drop of water is placed on the clean glass, which adheres to the glass plate to form a thin layer, and a clean glass sheet is taken out after being immersed in water, and the surface of the glass is stained with a layer of water. This phenomenon of liquid adhering to a solid surface is called wetting. The water is a wetting liquid relative to the glass, i.e., whether the liquid and the tubules can generate capillary phenomenon is determined by the relative materials of the liquid and the tubules.

The height of the liquid ascending or descending in the capillary phenomenon is calculated by the formula: h =

. Wherein h is the rising height of the liquid in the capillary tube and is unit cm;

is the surface tension coefficient of the liquid, with the unit of mN/m;

is the contact angle of a liquid surface to a solid surface in degrees;

carrying out liquid density and unit g/cm cultivation; g is gravity acceleration, and the unit cm/s has been used; r is the radius of the capillary in cm.

The embodiment of the application discloses an oil leakage sensing method.

Referring to fig. 1 and 2, the oil bleeding sensing method includes the steps of:

s100, adding a binder material which is dissolved or swelled after being contacted with oil into at least one preparation material of a conducting layer 1 and an insulating layer 2 which form the film capacitor;

s200, introducing low-voltage alternating current into the two conducting layers 1 of the film capacitor to enable the film capacitor and an alternating current power supply end to form an alternating current loop;

s300, acquiring an electric signal in an alternating current loop;

and S400, generating a sensing signal according to the comparison result of the electric signal and the signal threshold value and outputting the sensing signal. And judging whether the oil leaks or not by acquiring an electric signal in an alternating current loop in which the film capacitor is positioned. That is, when the oil leaks, the oil comes into contact with the conductive layer 1 and/or the insulating layer 2 of the film capacitor. The oil and the binder in the conductive layer 1 and/or the insulating layer 2 are subjected to a dissolution or swelling reaction, so that an electric signal in an alternating current loop is subjected to sudden change. After the electric signal is mutated, the induction signal is generated. The staff can know the leakage information of the oil liquid, so as to process in time. The oil leakage condition is sensed by directly using the binder which reacts with the oil, so that the sensing precision is high and the influence of the external environment is not easy to occur. Such as weather, thunderstorm weather, or people, vehicles, animals, etc., the false alarm rate is low.

It should be noted that the low-voltage alternating current in the present scheme can be selectively provided by an alternating current power supply with an output voltage of 4.3-12V. The ac power supply refers to a power supply product or a circuit module capable of providing ac power, and in one embodiment of the present disclosure, the output voltage of the ac power supply is 5V, and in another embodiment, the output voltage of the ac power supply is 5.5V. Two ends of an alternating current power supply are respectively connected to the two conducting layers 1 of the film capacitor, so that an alternating current loop is formed. The electrical signal in the ac loop may be obtained by a processor or a processing chip, and may be a voltage signal, a current signal, a clock signal, or a resistance signal. And the processor or the processing chip acquires the electric signal in the alternating current loop, compares the electric signal with the signal threshold, generates a sensing signal according to a comparison result and outputs the sensing signal. In order to facilitate the staff to know the oil leakage condition in time, the controller can be used for receiving the sensing signal output by the processor or the processing chip. When the controller receives the sensing signal, the alarm program can be controlled to give an alarm, and an alarm connected with the controller can also be controlled to give an alarm. The processor can be a single chip microcomputer or a PLC controller; the processing chip can be an MCU or an integrated chip; the controller can be a PC terminal or a PLC control system.

Referring to fig. 2, a material for manufacturing the conductive layer 1 of the film capacitor is made of a mixture of at least conductive powder and a binder, and a material for manufacturing the insulating layer 2 is a film-forming polymer material, such as polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polyester, polycarbonate, polyphenylene sulfide, polyethylene naphthalate, polyethersulfone, polyetherimide, polyimide, or the like. The binder comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material. The conductive powder is made of conductive materials, such as conductive metal powder including graphite powder, aluminum powder, copper powder, silver powder and the like, and conductive carbon powder including conductive carbon fiber, graphene, carbon nanotube, ketjen black and the like can be used as the conductive powder.

Referring to fig. 2, an embodiment of manufacturing the conductive layer 1 includes mixing and dissolving a binder and a solvent at a certain ratio to form a solution when manufacturing the conductive layer 1. And then adding conductive powder into the solution, and uniformly stirring. The solvent is selected from organic solvent with solubility parameter of 14-20, such as aliphatic hydrocarbon such as petroleum ether and n-hexane, aromatic hydrocarbon such as benzene, and organic solvent such as carbon tetrachloride. Then, the solution is applied to the surface of the insulating layer 2 by applying a brush, and the solvent in the solution is removed by natural air drying or vacuum drying, thereby forming the conductive layer 1. When oil leakage sensing is required for an annular oil conveying structure such as a pipeline, the solution needs to be coated on the surface of the insulating layer 2 in a winding way to form at least one continuous conductive belt. When the film capacitor is prevented from being laid, the conductive layer 1 forms a coil structure. In addition, the conductive layer 1 can be prevented from forming a coil structure by changing the laying mode of the film capacitor.

When oil leaks, the oil comes into contact with the conductive layer 1 and the insulating layer 2. As the amount of oil leakage increases, the oil penetrates the insulating layer 2 or comes into contact with another conductive layer 1 from the side of the film capacitor. The binder in the conductive layer 1 and the oil undergo a dissolution or swelling reaction. When the binder and the oil solution are dissolved, the conductive powder loses the fastening function of the binder and flows onto the surface of the insulating layer 2, resulting in an increase in the distance between the conductive powder, and thus in an increase in the resistance of the conductive layer 1. As the amount of the oil in contact with the conductive layer 1 increases, the degree of dissolution of the binder increases, causing local breakage of the conductive layer 1. When the two conductive layers 1 are locally broken, the alternating current circuit of the film capacitor is in an open circuit state.

When the swelling reaction occurs, the binder causes the distance between the conductive powders to increase, resulting in an increase in the resistance value of the conductive layer 1 and even the conductive layer 1 being unable to conduct electricity. Thereby causing the AC circuit in which the film capacitor is located to be in an open circuit state.

As another embodiment of the film capacitor in this example, referring to fig. 2, a material for preparing the insulating layer 2 of the film capacitor is composed of at least a mixture of an insulating powder and a binder. The material for preparing the conductive layer 1 is composed of at least a mixture of conductive powder and a binder. Wherein the insulating powder is selected from polymer with solubility parameter of 14-20, such as styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low density polyethylene, linear low density polypropylene and polydimethylsiloxane. After the insulating powder is uniformly mixed with the binder, the insulating layer 2 is formed, and then the conductive layer 1 may be laid in the manner as in the previous embodiment of the film capacitor.

When oil leaks, the oil comes into contact with the conductive layer 1 and the insulating layer 2. The binder in the conductive layer 1 and the insulating layer 2 and the oil undergo a dissolution or swelling reaction. When the binder and the oil solution are subjected to a dissolution reaction, the distance between the conductive powder in the conductive layer 1 is increased, and even the conductive layer 1 cannot conduct electricity; the insulating layer 2 is dissolved by the binder to form a hole. Oil subsequently contacted with the film capacitor passes through the hole and is contacted with the other conducting layer 1, so that the resistance value of the film capacitor is increased, and even the film capacitor cannot conduct electricity. Thereby causing an increase in the resistance value or an open circuit in the ac circuit in which the film capacitor is located.

When the binder undergoes a swelling reaction with the oil, the distance between the conductive powders in the conductive layer 1 that preferentially contact the oil increases, and the resistance value of the conductive layer 1 increases. The insulating layer 2 is expanded and deformed, so that the other conductive layer 1 is pulled, and the distance between the conductive powders in the pulled conductive layer 1 is increased. If the degree of expansion and deformation of the insulating layer 2 continues to increase, the conductive layer 1, which is pulled, is likely to be locally broken.

As still another embodiment of the film capacitor in this example, referring to fig. 2, a material for preparing the insulating layer 2 of the film capacitor is composed of at least a mixture of an insulating powder and a binder. The conductive layer 1 is made of conductive powder. The conductive layer 1 may be fixed on the surface of the insulating layer 2 by means of adhesion or the like. When only the insulating layer 2 is provided with the adhesive, the conductive layer 1 is formed into a flexible layer structure that can be deformed by deformation of the insulating layer 2. When the oil is in contact with the insulating layer 2, the binder in the insulating layer 2 undergoes a dissolution or swelling reaction. When the dissolution reaction occurs, the insulating layer 2 forms a hole, and the conductive layers 1 on both sides deform and move in opposite directions due to the hole, so that the contact is caused, and the alternating current circuit forms a short circuit state. When the swelling reaction occurs, the insulating layer 2 expands, the conductive layers 1 on both sides are pulled and move back and forth along with the expansion of the insulating layer 2, and thus the conductive layers are pulled apart, so that the resistance of the alternating current loop is increased or the alternating current loop is broken.

Based on the above embodiment, when the electrical signal in the ac loop is obtained, the electrical signal is subjected to filtering, denoising, calibration, amplification, and the like, and may be specifically implemented by an algorithm or a circuit such as a filter, a calibration circuit, a power amplifier circuit, and the like, which are integrated in a processor or a processing chip. In addition, when the current in the ac loop is small and does not meet the range processed by the collector, the current signal needs to be amplified. In order to obtain the value of the electrical signal, the processing such as sampling, time domain transformation and/or frequency domain analysis may be implemented in a processor or a processing chip by a circuit such as a filter, a signal processor, an amplifier, or an algorithm program.

After the electrical signal is acquired, the step S400 of generating and outputting a sensing signal according to the result of comparing the electrical signal with the signal threshold includes:

when the numerical value variation range of the electric signal is larger than or equal to the signal threshold, generating a sensing signal and outputting the sensing signal; wherein the value of the electrical signal comprises a frequency and/or an amplitude.

Specifically, a voltage signal in the alternating current circuit is collected, and when the oil is in contact with the film capacitor, the resistance value in the alternating current circuit is increased, or the alternating current circuit is in an open circuit or in a short circuit. Causing the voltage signal to change. At this time, the processor or the processing chip calculates the difference of the voltage signal values before and after the change. The difference is compared to a signal threshold. And if the difference value is greater than the signal threshold value, generating a sensing signal, otherwise, not generating.

As another embodiment of the present disclosure, the step S400 of generating and outputting the sensing signal according to the result of comparing the electrical signal with the signal threshold includes:

and when the value of the electric signal exceeds a signal upper limit threshold value and/or is lower than a signal lower limit threshold value in the signal threshold value, generating and outputting a sensing signal.

Specifically, a voltage signal in the ac loop is collected, and a value of the collected voltage signal is compared with a signal threshold. The signal threshold includes an upper signal threshold and a lower signal threshold. And when the value of the voltage signal exceeds a signal upper limit threshold value and/or is lower than a signal lower limit threshold value, generating and outputting a sensing signal.

The implementation principle of the embodiment 1 is as follows: the adhesive material is added to the preparation material of the conductive layer 1 and/or the insulating layer 2 of the film capacitor, and then the film capacitor is connected into an alternating current loop. And judging whether the oil leaks or not by acquiring an electric signal in an alternating current loop in which the film capacitor is positioned. When the oil leaks and contacts the film capacitor, the adhesive and the oil undergo a dissolution or swelling reaction, so that the resistance value of the alternating current loop in which the film capacitor is positioned is increased, or the alternating current loop is open or short-circuited. Resulting in a sudden change in the electrical signal in the ac loop. At the moment, a sensing signal is generated and output to remind the working personnel of oil leakage.

The embodiment of the application also discloses a seepage oil response membrane for response fluid. Referring to fig. 3, the oil-bleeding sensing film includes two conductive layers 1 and an insulating layer 2 between the two conductive layers 1. And a cementing layer is coated between the conductive layer 1 and the insulating layer 2. At least one of the cementing layer and the insulating layer 2 is oil solution material or oil solution swelling material.

As an embodiment of the oil-bleeding sensing film, referring to fig. 3, both the cementing layer and the insulating layer 2 are oil-dissolved materials or oil-swollen materials. Wherein, the conducting layer 1 is formed by at least bonding conducting powder through a cementing layer. The conductive powder comprises at least one of graphite powder, aluminum powder, copper powder, silver powder, conductive carbon fiber, graphene, carbon nano tube and Ketjen black material; the cementing layer comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, low-density polyethylene, low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material; the insulating layer 2 includes at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene-propylene rubber, polystyrene, low-density polyethylene, low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer, and carboxymethyl cellulose material.

In addition, the insulating layer 2 can be formed by mixing insulating powder in the oil solution material or the oil solution swelling material besides the oil solution dissolving material or the oil solution swelling material; or the insulating layer 12 is formed by bonding insulating powder through a cementing layer. The insulating powder is a polymer with a solubility parameter of 14-20; specifically, the insulating powder comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene and polydimethylsiloxane materials. As another embodiment of the oil-bleeding sensing film, referring to fig. 3, the cementing layer is an oil-dissolved material or an oil-swollen material, the insulating layer 12 is not an oil-dissolved material or an oil-swollen material, and the insulating layer is made of at least insulating powder. The conductive layer 1 is formed by bonding at least conductive powder through a cementing layer. The conductive powder comprises at least one of graphite powder, aluminum powder, copper powder, silver powder, conductive carbon fiber, graphene, carbon nano tube and Ketjen black material; the insulating layer 2 is made of a film-formable polymer material, such as polyvinyl chloride or polytetrafluoroethylene.

As another embodiment of the sensor film, referring to fig. 3, the insulating layer 2 is an oil-soluble material or an oil-swellable material, and the cementing layer is not an oil-soluble material or an oil-swellable material. In order to facilitate the detection of the oil, the conductive layer 1 is a flexible structure capable of deforming along with the local change of the insulating layer 2.

Referring to fig. 3, the conductive layer 1 is formed of at least one conductive tape laid on one side of the glue layer. As an embodiment of the conductive layer 1, one conductive tape is provided, and the conductive tape is laid on the adhesive layer in a circuitous manner, and gaps 3 are provided between adjacent conductive tapes. The gap 3 allows alternating current to flow through any position of the conductive strip when alternating current flows through the conductive strip. When being convenient for make fluid and cementing layer contact, cause the signal of telecommunication data in the alternating current circuit that the conduction band was located to change.

As another embodiment of the conductive layer 1, referring to fig. 4, the conductive tape is provided in a plurality of strips, each of which is laid on the surface of the adhesive layer, and the plurality of strips are parallel to each other. A gap 3 is formed between adjacent conductive strips. When the oil-permeable induction membrane needs to be applied, a plurality of conductive belts are connected in series in the alternating current loop by using a lead.

As still another embodiment of the conductive layer 1, referring to fig. 5, a plurality of conductive tapes are provided, each of which is laid on a surface of the adhesive layer and is provided in a winding manner. Adjacent conductive strips on the same surface are connected end to end.

Note that, in order to ensure that when ac current is supplied to the conductive layer 1, ac current flows to any position of the conductive layer 1. So that gaps 3 are formed between the conductive strips. But it is also possible to separate the conductive strips by means of an insulating medium.

Referring to fig. 5, a protective layer 4 is disposed on a surface of the conductive layer 1 away from the insulating layer 2, the protective layer 4 is made of an insulating material, and specifically, the protective layer 4 includes at least one of rubber or plastic material. The protective layer 4 physically protects the conductive layer 1 and the insulating layer 2, and helps prevent the protective layer 4 and the insulating layer 2 from being scratched by other objects and the structure from being damaged. The protective layer 4 can also be provided as an anti-corrosion layer, made of an anti-corrosion material. The conductive layer 1 and the insulating layer 2 are protected from corrosion. The protective layer 4 is fixedly connected with the conductive layer 1 in a bonding mode or a hot melting mode. At least one of the two protective layers 4 is provided with a number of through-holes 41 for the inflow of oil to the glue layer. In fig. 5, only one of the two protective layers 4 is provided with a through hole 41. When the induction film is used, the protective layer 4 provided with the through-hole 41 is brought into contact with the outer peripheral surface of the oil liquid conveying structure. When oil leaks, the oil passes through the through hole 41 and abuts against the glue layer. It will be understood that through holes 41 may be provided in both protective layers 4.

Referring to fig. 5, the protective layer 4 and the through-holes 41 form a capillary phenomenon with the oil. The capillary phenomenon in this application refers to the condition that fluid gets into in the through-hole 41 automatically because of capillary phenomenon after fluid contacts with protective layer 4. I.e., refers to the phenomenon of the wetting liquid rising in the capillaries. The realization method is that the material which has insulating property and can form infiltration with the sensed oil is selected according to the type of the oil sensed by the sensing film. Since the height at which the liquid rises in the capillary phenomenon is related to the radius of the capillary, that is, the radius of the through-hole 41 can be set according to the thickness of the protective layer 4. I.e. the smaller the radius of the through-hole 41, the greater the depth of the oil entering the through-hole 41, thereby facilitating the contact of the oil with the conductive layer 1.

The implementation principle of the induction film in the embodiment of the application is as follows: when sensing of oil is required, for example, real-time detection of oil leakage is performed. The induction film can be arranged on the periphery of the oil liquid conveying structure, and the two conductive layers 1 of the induction film are connected in the same alternating current loop. The induction film is in a capacitance structure, and electric signal data are generated in the alternating current loop. When the oil contacts the induction film, the induction film increases the resistance value in the alternating current loop, and even the alternating current loop is in an open circuit state. Resulting in abrupt changes in the electrical signal data in the ac loop. By acquiring the change of the electric signal data in the alternating current circuit, whether the oil leaks can be known.

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 (8)

1. An oil-permeable sensing film, which is characterized in that: the conductive layer comprises two conductive layers (1) and an insulating layer (2) positioned between the two conductive layers (1), wherein a cementing layer is coated between each conductive layer (1) and each insulating layer (2); at least one of the cementing layer and the insulating layer (2) is an oil solution material or an oil solution swelling material;

the conducting layer (1) is fixedly connected with the cementing layer, and the conducting layer (1) is formed by at least one conducting belt paved on one surface of the cementing layer; the conducting strips are laid on the gluing layer in a roundabout mode, and gaps (3) are formed between every two adjacent conducting strips.

2. The oil-bleeding sensing film according to claim 1, wherein: the cementing layer is an oil solution dissolving material or an oil solution swelling material; the conducting layer (1) is formed by at least bonding conducting powder through a cementing layer.

3. The oil-bleeding sensing film according to claim 2, wherein: the insulating layer (2) is an oil solution material or an oil solution swelling material.

4. The oil-bleeding sensing film according to claim 3, wherein: the conductive powder comprises at least one of graphite powder, aluminum powder, copper powder, silver powder, conductive carbon fiber, graphene, carbon nano tube and Ketjen black material.

5. The oil-bleeding sensing film according to claim 4, wherein: the cementing layer comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material;

the insulating layer (2) comprises at least one of styrene-butadiene rubber, polyisobutylene, polybutadiene, ethylene propylene rubber, polystyrene, linear low-density polyethylene, linear low-density polypropylene, polydimethylsiloxane, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer and carboxymethyl cellulose material.

6. The oil-bleeding sensing film according to claim 1, wherein: one surface of the conducting layer (1), which is far away from the insulating layer (2), is provided with a protective layer (4), and at least one of the two protective layers (4) is provided with a plurality of through holes (41) for oil to flow into and reach the conducting layer (1);

the protective layer (4) is made of an insulating material.

7. The oil-bleeding sensing film according to claim 6, wherein: the protective layer (4) is fixedly connected with the conductive layer (1); the protective layer (4) comprises at least one of a rubber or a plastic material.

8. The oil-bleeding sensing film according to claim 6, wherein: the protective layer (4) and the through holes (41) are used for forming a capillary phenomenon with oil.

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