CN115628822A - Method for detecting temperature of two-dimensional interface between heterogeneous structures and structure thereof - Google Patents

Abstract

The invention discloses a method for detecting the temperature of a two-dimensional interface between heterogeneous structures and a structure thereof. In general, the overall method framework of detection is to physically connect a thermistor material element with a temperature measuring interface, and then perform analog-to-digital signal conversion on the thermistor material element through an electronic component, thereby outputting a temperature value. The method of the invention adopts a one-dimensional heat conduction model, and can greatly improve the accuracy of temperature sensing output numbers. By using a small enough part on the surface of the temperature measuring body, the texture of the part is uniform, the thermal parameters of the material are relatively fixed, so that a one-dimensional heat conduction model which can be close to an ideal two-dimensional plane is adopted in the heat flow mode, the output temperature value has controllable smaller deviation, and the real-time property is enhanced. The method can be applied to scenes with high-precision temperature measurement requirements, such as human body surfaces, surfaces of mechanical and electronic devices, new energy battery cells, heating and non-burning electronic smoking sets and the like.

Description

Method for detecting temperature of two-dimensional interface between heterogeneous structures and structure thereof

Technical Field

The invention relates to the technical field of temperature detection, in particular to a method for detecting the temperature of a two-dimensional interface between heterogeneous structures and a structure thereof.

Background

The temperature detection scene with wide application mostly belongs to the temperature detection type aiming at the surface (namely a two-dimensional interface) of a solid object, such as human skin temperature detection, detection of heating of various devices and the surface of the object, and the like. The industry today typically monitors the temperature of the surface of an object using either thermal conduction or thermal radiation principles. The latter is like infrared temperature measurement rifle, receives convection current and external disturbance influence great, so generally adopts the heat conduction principle in the higher precision temperature measurement requirement scene. A general method frame for heat conduction temperature measurement is that a resistance type thermosensitive element is fixed on a temperature measured interface, two electrode wires are led out to a circuit system, and an ADC (analog-to-digital converter) component collects the resistance value of the thermosensitive element to realize temperature output. The two sides of the detected interface are generally different materials (such as an object exposed to air). The two heterogeneous material spaces generally have different temperatures (for example, the surface of a certain heat-generating device body is detected at normal temperature). At some point in time when the steady state of heat transfer is reached, a spatial field of decreasing temperature gradient will form between the two media. The essence of the temperature sensor is that the resistance value reading of the thermosensitive element in the temperature field is output, then algorithm correlation correction is carried out, and a temperature value is output, wherein the position and the assembly consistency of the thermosensitive element in a steady-state temperature gradient field space directly determine the accuracy of the temperature sensor and the product quality. Along with the continuous abundance of the material world brought by the development of science and technology, the temperature detection requirements with higher requirements are continuously generated, lower temperature detection deviation and higher assembly consistency are required, and therefore serious thermal failure accidents such as new energy battery cores, various motors, various control equipment and the like are avoided. The current traditional method has obvious defects in temperature measurement output accuracy and response timeliness.

The theoretical model of heat transfer is based on the mathematical relation description of the heat flux of the space plane and the temperature value of the space point, and in practical application, the temperature detection is often required to be carried out on the surfaces of various objects. Generally, a thermistor type element is fixed near the surface of a temperature measuring body, and then electric leads at two ends of the thermistor type element are connected to an analog-to-digital conversion circuit, so that a temperature value is output through resistance-temperature conversion. However, the traditional thermistor has a large geometric dimension and a relatively close three-dimensional dimension ratio, and the deviation and the inconsistency of the output temperature values are large due to various process limitations and low assembly consistency of a manufacturing process, a packaging method and the like of the temperature measuring device. Specifically, when the temperature of the surface of an object exposed to air is detected, substances on two sides of a two-dimensional interface generally have different parameters such as thermal conductivity, specific heat capacity and the like and different temperature values, and a temperature field distribution exists due to the temperature difference between the air and the surface of the temperature-measuring object, as shown in fig. 1, the temperature T0 and the temperature Tn of the substances on two sides of the interface are different, and a temperature gradient field exists in the space between T0 and Tn in a steady state.

The two sides of the interface are made of materials with different materials, different heat conduction coefficients and different specific heat capacities. Most of the time, the two sides of the interface are considered to be thermostats with different temperatures. The temperature sensing element is generally a thermistor-type material element having a temperature effect, and metal electrodes for conductive leads are provided at both ends of a thermistor-type material element main body. Generally, the temperature sensing element is made of three-dimensional materials (such as a transition metal oxide ceramic sintered body), in a scene of two-dimensional interface temperature detection, the resistance reading of the temperature sensing element represents the average temperature value in a small three-dimensional space of the element in a temperature field, and a silicone grease filling mode is adopted during assembly, so that the geometric size is inconsistent, and the output temperature deviation and randomness are relatively large. Under the temperature measurement scene with higher requirements, once the estimated deviation value of the actual output temperature exceeds the fault-tolerant upper limit of the system design, the thermal failure accident of the control mechanism can be caused.

Therefore, how to optimally design the temperature measuring device and properly arrange the spatial position in the temperature gradient field inside the sensitive element so that the sum (Terror) of the deviation and the uncertainty of the reading and the real temperature value of the measured surface does not exceed the upper limit of the fault tolerance of the design target of the temperature measuring system is the key of the design of the high-precision temperature sensor.

Disclosure of Invention

The invention mainly aims to provide a method for detecting the temperature of a two-dimensional interface between heterogeneous structures and a structure thereof, so as to solve the defects in the prior art.

In order to realize the purpose, the technical scheme adopted by the invention is as follows:

a method for detecting the temperature of a two-dimensional interface between heterostructures is characterized by comprising the following steps:

s10: fixing the film or sheet carrier on the surface of the object to be measured by a physical or chemical method;

s20, fixing the thin flat plate type thermosensitive element on the surface of the film or the sheet-shaped carrier by methods such as physical or chemical deposition and the like;

s30, respectively leading out two electric leads at two ends of the thermosensitive element;

and S40, packaging a heat insulation layer on one side of the object with the temperature measured by the thermosensitive element.

Further, in S10, the film or sheet-shaped support is a metal, a ceramic with high thermal conductivity, or an organic thin film.

Further, in S10, the thickness of the film or sheet-shaped support is in the micrometer range.

Further, in S20, the thickness (δ) of the thin flat plate-type thermosensitive element is: 0 μm < δ <5 μm.

Further, in S30, the thin flat plate type thermo-sensitive element is connected to an external temperature measuring device through two wires at two sides, respectively.

Further, the heat insulation layer is made of a material with low heat conductivity coefficient.

The invention also provides a structure for detecting the temperature of the two-dimensional interface between the heterogeneous structures, which is used for realizing the method for detecting the temperature of the two-dimensional interface between the heterogeneous structures, and comprises the following steps:

the film or sheet carrier is fixed on the surface of the object to be measured by a physical or chemical method;

the thin flat plate type thermosensitive element is fixed on the surface of the film or the sheet-shaped carrier by physical or chemical deposition and other methods; two leads are respectively led out from two ends of the thin flat plate type thermosensitive element and are connected with an external temperature measuring device.

And the heat insulation layer is encapsulated on the other side surface of the thin flat plate type thermosensitive element.

The invention reduces the traditional three-dimensional heat conduction model to an approximate one-dimensional heat conduction model, and greatly improves the accuracy of temperature sensing. The one-dimensional heat conduction model which can approach to an ideal two-dimensional plane in a heat flow mode is realized by utilizing a small enough part on the surface of the temperature measuring body, the texture is uniform, and the thermal parameters of the material are fixed. The temperature of the surface of the object can be detected more accurately in real time. The method is applied to important scenes such as human body surfaces, surfaces of mechanical and electronic devices, new energy battery cores, various electromechanical devices and the like.

Drawings

In order to more clearly illustrate the embodiments or technical solutions of the present invention, the drawings used in the embodiments or technical solutions of the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram showing the difference between the temperatures T0 and Tn of two side substances in the present invention;

FIG. 2 is an assembly schematic diagram of a conventional ntc thermistor;

FIG. 3 is a schematic diagram of assembly for detecting temperature of a two-dimensional interface between heterostructures according to an embodiment of the present invention;

FIG. 4 is a flowchart of a method for detecting a temperature of a two-dimensional interface between heterostructures according to an embodiment of the present invention;

FIG. 5 is a structural diagram of two-dimensional interface temperature detection between heterogeneous structures according to an embodiment of the present invention;

FIG. 6 is a comparison of the two-dimensional interface temperature measurements of the heterostructure devices of the present invention with conventional ntc measurements.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The temperature of the surface of a certain object is detected in the air, the surface is an interface between two different substances in a physical model, the object to be detected is a solid with a rigid or flexible surface, the other substance is air, and the two substances respectively have different thermodynamic parameters such as heat conductivity coefficient, specific heat capacity and the like. In general, the two substances each have a different temperature, and the two temperatures differ, as shown in FIG. 1.

In the prior art, to detect the temperature of the interface, a device including a thermal sensitive element is required to be installed on the interface, and then the device is exposed to the air to output the temperature of the interface to be measured, the thermal sensitive element adopted in the prior art is generally a geometric body with three-dimensional dimensions, a negative temperature coefficient thermistor ntc is widely used in the industry, and in order to fix the ntc on the interface, the ntc is generally tightly wrapped by using heat-conducting silicone grease, and then is fixed on the interface to be measured by adhesion, as shown in fig. 2. A temperature gradient field is formed within the thermally conductive silicone grease and the temperature field takes the form of three-dimensional heat conduction. When the analog-to-digital conversion (ADC) part of the circuit system reads the resistance value of ntc, the resistance value is corrected, and the temperature representing the interface is output.

Assuming the temperature measuring device as an approximately steady-state system (ignoring sensor current heating, possible chemical reaction heating, convection and radiative heat dissipation), according to the fourier three-dimensional heat conduction formula:

wherein Q is heat flux, k is heat conductivity coefficient of the heat-conducting silicone grease (a heat-conducting insulating silicone material with heat conductivity of 1W-5W/M.K), A is area x, y, z is three-dimensional orthogonal coordinate axis, and T is temperature value.

Due to the limitation of the manufacturing process, the boundary geometric parameters of the heat-conducting silicone grease on each dimension of xyz have larger randomness, and Tsensor is set as a read temperature value of the thermistor after the resistance value is converted by a circuit, namely the temperature evaluation formula of the sensor is as follows:

Tsensor1＝T0-(errorTx+errorTy+errorTz) (2)

wherein Tsensor1 is a temperature estimated value (i.e., a temperature measured value output by the sensor), T0 is a true physical model temperature value of the measured surface, and errorTy, and errorTz are estimated bias values on XYZ coordinate axes.

In order to reduce the measurement deviation value and improve the accuracy of the measured value Tsensor1, the invention reduces the dimensionality of the temperature gradient field from three dimensions to one dimension, i.e. the errorTx, errorTy, errorTz are simplified to one-dimensional errorT in the temperature evaluation formula, as shown in fig. 3, the measurement evaluation formula is changed to:

Tsensor2＝T0-errorT (3)

the deviation value errorT is evaluated, and because of the fewer variables, the errorT is smaller than the values of errorTx + errorTy + errorT in equation (2), and it is easier to limit its upper limit by design methods.

The specific method is as shown in fig. 4:

s10: fixing the film or sheet carrier on the surface of the object to be measured by a physical or chemical method;

s20, fixing the thermosensitive element on the surface of the film or sheet-shaped carrier by physical or chemical deposition and other methods;

s30, respectively leading out two wires at two ends of the thermosensitive element;

and S40, packaging a heat insulation layer on the other side of the thermosensitive element and the object to be measured.

In this embodiment, the film or sheet-like support is a metal, a highly thermally conductive ceramic, or an organic thin film. The thickness is in the order of micrometers and is therefore negligible compared to the dimensions of the thermometric device, it can be assumed that heat is conducted only from a direction perpendicular to the surface of the film or sheet-like support, and the deviation values errorTx and errorTy in equation (2) are both close to 0, thus bringing the temperature of the side of the film or sheet-like support closer to T0.

Further, the thickness (δ) of the thin flat plate type heat-sensitive element is: 0 μm < delta <5 μm (the thickness is negligible, the same principle as above is used, and the description is omitted here, in practical effect, the effect is the best when delta <1 μm, and the effect of 1-5 μm is good), so that the temperature value of the thermosensitive element is closer to T0, and the thermosensitive element is respectively connected with an external temperature measuring device through two wires at two ends. When the temperature of the object to be measured is measured, the temperature of the object to be measured is converted and calculated through the external temperature measuring device, so that the packaging space of the temperature measuring device on the object to be measured is reduced, and the heat loss is reduced.

Further, the heat insulation layer is made of a material with low thermal conductivity coefficient, such as an aerogel product and the like. The heat-sensitive element has smaller thermal buffer in heat conduction, so that the response speed of the heat-sensitive element is higher.

In this embodiment, the film or sheet-shaped carrier is close to the temperature measuring interface to perform the function of heat transfer, the right side of the film or sheet-shaped carrier is close to the two-dimensional thin-plate type thermosensitive element, and the purpose of the heat-insulating layer is to insulate heat to form a temperature drop on both sides, so that the temperature value of the thin-plate type thermosensitive element in the steady-state temperature drop gradient field is close to T0.

In the film or sheet-like support, the thermosensitive element and the heat insulating layer, the material and the dimensional design and processing of each material are easy to precisely control, so that theoretically the deviation value errorT of formula (3) can be designed and controlled, so that Tsensor2 is closer to T0 than Tsensor1, and the deviation value errorT can be quantitatively evaluated, whereas errorTx, errorTy, and errorTz in the conventional mode are not easily controlled and quantitatively evaluated.

In the prior art, the heat conductive silicone grease shown in fig. 3 also has high specific heat capacity and inevitable thermal buffering in heat conduction, which results in slow response of the conventional ntc element.

For both of these reasons, it was concluded that Tsensor2 is more rapid and accurate than Tsensor 1.

The invention also provides a structure for detecting the temperature of the two-dimensional interface between the heterogeneous structures, which is used for realizing the method for detecting the temperature of the two-dimensional interface between the heterogeneous structures, and with reference to fig. 5, the method comprises the following steps:

the film or sheet carrier 1 is fixed on the surface of an object to be measured by a physical or chemical method; so that one surface of the film or the sheet-shaped carrier is fully contacted with the surface of the object to be measured; the embodiment adopts metal with nanometer or micrometer thickness, high heat conduction ceramic or high heat conduction material of an organic film, and reduces the heat resistance.

A thin flat plate type thermosensitive element 2 on the surface of a film or sheet-like support by physical or chemical deposition or the like; and positive and negative wires are respectively led out from two ends of the thin flat plate type thermosensitive element and are connected with an external temperature measuring device.

And the heat insulation layer 3 is packaged on the outer side surface of the thermosensitive element. The present embodiment uses a thermal insulation material with a low thermal conductivity, such as an aerogel product. The thermal insulation layer forms temperature drop on two sides thereof, so that the temperature value of the thermosensitive element in the steady-state temperature drop gradient field is close to one surface of the surface temperature T0 of the measured object.

The data of the contact thermometer manufactured by the structure of the present invention and the contact thermometer manufactured by the prior art in fig. 3 in the actual test show that, as shown in fig. 6, the former is about 1/20 of the latter in temperature equilibrium time after contacting the skin, and according to the certification report of the third-party authority metering institution, the temperature measurement error of the former reaches 0.01 degrees and is reduced by 10 times compared with the latter.

Of course, the method and the structure of the invention can be applied to important scenes such as surface temperature measurement of mechanical electronic devices, surface of new energy battery cells, electronic cigarettes and the like besides the contact type clinical thermometer.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. A method for detecting the temperature of a two-dimensional interface between heterogeneous structures is characterized by comprising the following steps:

s10: fixing the film or sheet carrier on the surface of the object to be measured by a physical or chemical method;

s20, fixing the thin flat thermistor type element on the surface of a film or a sheet carrier by physical or chemical deposition and other methods;

s30, respectively leading out two electric leads at two ends of the thin flat thermistor element;

and S40, packaging a heat insulation layer on one side of the outer surface of the thin flat thermistor type element.

2. The method according to claim 1, wherein in S10, the film or sheet-like support is a metal, a highly thermally conductive ceramic, or an organic thin film.

3. The method of claim 1, wherein in S10, the thickness of the film or sheet-like support is in the order of micrometers.

4. The method according to claim 1, wherein in S20, the thickness (δ) of the thermistor is: 0 μm < δ <5 μm.

5. The method of claim 1, wherein in S30, the thermistor is connected to an external electronic temperature measuring device through two wires at two ends.

6. The method according to claim 1, wherein in S40, the thermal insulation layer is a low thermal conductivity material.

7. A structure for detecting the temperature of a two-dimensional interface between heterostructures is used for realizing the method for detecting the temperature of the two-dimensional interface between the heterostructures according to any one of claims 1 to 6, and the method comprises the following steps:

the film or sheet carrier is fixed on the surface of the object to be measured by a physical or chemical method;

the thin-plate thermistor element is fixed on the surface of a film or a sheet carrier by physical or chemical deposition and other methods; two ends of the thermosensitive element are respectively led out of two electric leads and connected with an external temperature measuring device;

and the heat insulation layer is packaged on the external side surface of the thermosensitive element.

8. The structure of claim 7, wherein the film or sheet-like support is a metal, a highly thermally conductive ceramic, or an organic thin film.

9. A structure for detecting the temperature of a two-dimensional interface between heterostructures according to claim 7, wherein the thickness (δ) of said thermosensitive element is: 0 μm < δ <5 μm.

10. A structure for detecting the temperature of a two-dimensional interface between heterostructures as claimed in claim 7, wherein said thermal insulating layer is a low thermal conductivity material.

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