119 results about "Thermal diffusivity" patented technology

A vacuum insulating panel may include: a first glass substrate; a second glass substrate; a plurality of spacers provided in a gap between at least the first and second substrates, wherein the gap is at a pressure less than atmospheric pressure; a seal provided between at least the first and second substrates, the seal including a first ceramic seal layer and a second ceramic seal layer, wherein the second ceramic seal layer is located between at least the first ceramic seal layer and the first glass substrate; and wherein one or more of: (i) a thermal (TC) conductivity of the first ceramic seal layer is be less than a thermal conductivity of the first glass substrate, and wherein the thermal conductivity of the first glass substrate is less than a thermal conductivity of the second ceramic seal layer, so that the thermal conductivity of the second ceramic seal layer is greater than the thermal conductivity of the first substrate and greater than the thermal conductivity of the first ceramic seal layer; (ii) a thermal conductivity of the second ceramic seal layer is greater than a thermal conductivity of the first ceramic seal layer; and / or (iii) a ratio TDp1 / TDg, where TDp1 represents a thermal diffusivity (TD) of the second ceramic seal layer and TDg represents a thermal diffusivity of the first glass substrate, is at least 1.020 and wherein the thermal diffusivity of the second ceramic seal layer is greater than a thermal diffusivity of the first ceramic seal layer.

The invention relates to the technical field of laser material processing, and discloses a laser annealing temperature control method and device.The method comprises the steps that the specific heat capacity, the heat conductivity coefficient, the heat diffusivity, the heat radiation rate, the heat reflectivity and the heat loss coefficient are obtained, and a material thermal characteristic model is established; performing grid division according to the material thermal characteristic model to obtain a laser energy density parameter; extracting a thermal strain coefficient according to the laser energy density parameter, and establishing a temperature-thermal strain mapping relation prediction model; dynamically adjusting a laser power proportion and a pulse width time sequence according to the temperature-thermal strain mapping relation prediction model to obtain temperature field distribution data; according to the temperature field distribution data, carrying out shortest path analysis to obtain a temperature regulation and control decision; and according to the temperature regulation and control decision, inputting a preset control regulation model, and combining reinforcement learning iteration optimization parameters to obtain a temperature control scheme. According to the method, large-range temperature crossing and fine adjustment in an extremely short time can be realized.

A heater assembly for a haircare appliance comprising a hair contacting member 42, a heating element 40 to heat the contact member and a support member 54 in thermal contact with the heating element and contact member which has a thermal diffusivity of at least 1.0 mm2 / s. The support member 54 may be a polymer foam such as silicone foam. A heat spreading layer with a thermal resistance no greater than 22 Kelvin / Watt may be used. The heating elements may extend across 95% of the length of the hair-contacting surface. A sensor system may be provided to increase the temperature as the appliance moves from a root to a tip of a tress of hair. The heating may be based on a time relating to the length of tress. The support member may be flexible to allow deflection.

The invention provides a method for automatically monitoring the humidity of a corrugated board on line, and belongs to the technical field of corrugated board production. Uniform thermal pulses are applied to the surface of the corrugated board through a thermal infrared imaging device in combination with a thermal pulse excitation system, and high-resolution thermal response images are collected in real time. The system calculates thermal diffusivity and thermal attenuation characteristics based on an unsteady state heat conduction equation, generates a temperature distribution matrix, extracts a humidity characteristic spectrum by using a heat and humidity two-parameter neural network model, and establishes a corresponding relation between temperature and water content. Carrying out region segmentation through the humidity characteristic spectrum, identifying a humidity abnormal region, calculating a deviation value, and triggering an alarm when the deviation value exceeds a preset threshold value. The technical problem that in the prior art, corrugated board humidity detection mainly depends on manual sampling and special instruments, and real-time online monitoring on a production line cannot be achieved is solved.

A method may include performing, by a drilling system, a drilling operation to produce a wellbore in a geological region of interest. The method may further include determining time elapse data describing an amount of time between the drilling operation and a hydraulic stimulation operation. The method may further include determining borehole stress data based on the wellbore, reservoir data, and geological data. The method may further include determining thermal diffusivity data regarding a temperature front in the geological region of interest based on the time elapse data, the reservoir data, and the geological data. The method may further include determining a wellbore breakdown pressure of the geological region of interest based on the thermal diffusivity data, the geological data, the borehole stress data, and the reservoir data. The method may further include transmitting a command to a stimulation control system based on the wellbore breakdown pressure.

The invention relates to a thermal diffusivity high-precision inversion method based on a multi-terminal deep neural network, belongs to the technical field of infrared thermal wave nondestructive testing and material thermophysical property measurement, and particularly relates to the thermal diffusivity high-precision inversion method based on the multi-terminal deep neural network. The invention aims to solve the problems of low calculation efficiency, strong noise sensitivity and insufficient robustness in a traditional thermal diffusivity measurement method, and provides a thermal diffusivity high-precision inversion method based on a multi-end deep neural network for materials with damage defects. Specifically, the amplitude and phase of thermal waves are extracted by using a phase-locked thermal imaging technology, and stable characteristics describing the thermal diffusion process are obtained. A deep learning network taking space coordinates, excitation frequency, surface temperature information, amplitude and phase as input is constructed, and efficient and accurate measurement of the thermal diffusivity of a complex material is realized through multi-modal data fusion, an advanced direct current component removal technology and a multi-end deep neural network architecture.

The invention relates to the technical field of defect detection, and discloses a defective product detection method and system for high-temperature insulating brick production, and the detection system comprises a detection module, a heating determination module, a heating adjustment module and an evaluation module. The detection module adopts a laser heat conduction instrument and an infrared camera to perform periodic thermal wave heating on the to-be-detected brick body, and records temperature data to calculate thermal diffusivity so as to judge whether a defect area exists in the brick body or not; the heating determination module obtains the thickness of the brick body and determines the heating pulse width, the period duration and the heating power according to the thickness of the brick body; the heating adjusting module is used for compensating and adjusting the heating power according to the real-time environment temperature; the evaluation module is used for calculating an evaluation score. Through automatic and intelligent means, accurate detection of the internal defects of the high-temperature insulating bricks is realized, and the detection efficiency and accuracy are improved.

The invention relates to a surface material uniformity analysis method and system for an insulator of a power distribution network, and belongs to the technical field of data processing, and the method comprises the following steps: S1, obtaining an optical image, a thermal imaging image and ultrasonic echo data of the surface of the insulator; s2, performing image processing on the acquired optical image, extracting characteristic parameters of surface roughness, texture direction and texture consistency, and constructing a surface texture uniformity index; s3, thermal diffusivity and thermal resistance of different areas are calculated from the thermal imaging image, thermal parameter differences of the areas are compared, and a thermal performance uniformity evaluation value is formed; s4, aiming at the ultrasonic echo data, establishing a correlation model of the ultrasonic characteristics and the internal uniformity of the material; s5, the fusion analysis model comprehensively evaluates the uniformity of the surface material of the insulator; the method has the beneficial effects that the fusion analysis model realizes comprehensive evaluation of the uniformity of the surface material of the insulator from multi-dimensional data.

A thermo-optical plane source (TOPS) technique can be used to measure the thermal conductivity of materials. This high-throughput, simple, and efficient technique measures thermal conductivity with minimal sample preparation and limited restrictions on sample shape and geometry. Moreover, the TOPS technique works on solids, liquids, gels, and pastes with no change in implementation. The TOPS technique uses laser heating to induce a steady-state temperature rise in a material and infrared thermography to measure the corresponding temperature rise. Fourier's law is applied to directly measure thermal conductivity, rather than thermal diffusivity or effusivity, without any need to know the sample's density or heat capacity. It can measure thermal conductivities ranging from 0.05 W m-1 K-1to 60 W m-1 K-1at room temperature.

The invention belongs to the technical field of laser processing numerical simulation, and discloses a random forest model laser absorption coefficient efficient prediction method based on factor analysis, and a laser absorption coefficient data set comprises four parameters of laser power density, a forming coefficient, conductivity and thermal diffusivity. According to the method, multiple factors influencing the laser absorption coefficient in laser processing are comprehensively considered, the dimensionality of a data set is reduced, the feature correlation between data is low, and a high-quality training set is provided for subsequent training of a random forest model. Multiple Gaussian distribution linear mixing probability distributions are generated through a Gaussian mixture model to describe original data, new samples are generated through random sampling to form an incremental data set, the training effect of the random forest model is improved, and the over-fitting condition is avoided; through factor analysis, features with strong correlation are divided into one group, generation of a weak decision tree is avoided, the accuracy and convergence speed of the model are improved, and an efficient model training mode is realized.

The invention provides a concrete structure construction period temperature deformation cracking risk prediction method comprising the following steps: S1, temperature monitoring: after concrete structure pouring is completed, continuously monitoring a concrete internal and surface temperature development curve; s2, inverting thermal parameters, namely inverting an equivalent adiabatic temperature rise curve and an equivalent thermal diffusivity of concrete under a field condition and a convective heat transfer coefficient of the concrete under a template in-place condition by combining a monitoring temperature, an environment temperature and a heat preservation condition and utilizing a heat conduction equation inverse analysis method; s3, prediction in the form removal period and the later period: inputting the thermal parameters obtained by inversion into finite element software, performing temperature field prediction, switching a boundary condition to be a heat exchange coefficient after form removal, and simulating subsequent temperature evolution; s4, risk index calculation and grading: calculating a risk index, and quantifying or grading the cracking risk according to a set threshold value; s5, performing construction decision linkage; according to the method, the thermal parameters of the concrete can be quickly inverted by utilizing early field measured temperature data.

The invention belongs to the technical field of non-ferrous metal material processing, and particularly discloses a Ti575G titanium alloy bar and a preparation method and application thereof.The preparation method comprises the technological route of cogging forging, intermediate forging and forming forging, firstly, a large deformation technology above a phase transformation point is adopted, the thermal diffusivity of atoms under the high-temperature condition is fully utilized, and the thermal diffusivity of the atoms under the high-temperature condition is utilized; according to the method, the component and structure uniformity of a blank is greatly improved, then a repeated upsetting and drawing deformation mode is applied in a two-phase region, and meanwhile, the deformation uniformity of all positions of a bar is effectively improved by strictly controlling the temperature, the heat preservation time, upsetting and drawing deformation parameters and the like of each stage. The Ti575G bar prepared by the preparation method disclosed by the invention is uniform in component and structure, has matched strong plasticity and impact toughness characteristics, can completely meet strict requirements of wings, fuselage frames, undercarriages and weapon barrels of airplanes on the alloy bar, and is very suitable for industrial large-scale production.

A flow sensor including a fluid flow path, a first sensor configured to determine a first measurement of a thermal diffusivity and / or a viscosity of a fluid in the fluid flow path, a second sensor configured to determine a second measurement of a fluid flow velocity and / or a volumetric flow rate of the fluid in the fluid flow path, and at least one processor configured to adjust the second measurement based on the first measurement. A method including receiving fluid in a fluid flow path of a flow sensor, determining a first measurement of a thermal diffusivity and / or a viscosity of the fluid in the fluid flow path, determining a second measurement of a fluid flow velocity and / or a volumetric flow rate of the fluid in the fluid flow path, and adjusting the second measurement based on the first measurement.

The invention relates to an overmolding method for producing a component (1) having a decoration (2), also referred to as an overmolded part, said decoration (2) being made of an at least partially amorphous metal alloy (8), said method comprising the following steps: providing a blank (3) having at least one through-hole (4) which opens into the overmolded part (2) to be produced, said blank (3) being made of a first material having a low thermal diffusion coefficient or being at least partially plated with a layer made of said first material; providing an injection mould (6); positioning the blank (3) inside the injection mould (6); the liquid metal alloy (8) is injected through the through hole (4), and the through hole is communicated into the cavity of the injection mold (6) and / or the cavity of the blank (3); the blank (3) with the overmolded part (2) is demolded in order to obtain the component (1).

The present invention discloses a thermal tracer test device and method for determining the comprehensive hydrogeological conditions of an aquifer. The thermal tracer test device comprises a water storage system, a medium tank, a heating system, and a distributed fiber optic data acquisition system. The device has a simple structure and is intelligent and convenient to operate. The heating system can be used to excite a transient or continuous linear heat source. The distributed fiber optic data acquisition system monitors water pressure and temperature changes at various locations in real time, allowing for the study of comprehensive hydrogeological parameters such as groundwater flow rate and direction, permeability, thermal diffusivity, heat capacity, and thermal conductivity. The heating system and distributed fiber optic data acquisition system can be used for both indoor and field tests, offering simple operation, high data accuracy, and strong practicality.

The invention relates to the technical field of tree management, and discloses an ancient and famous tree dynamic early warning and intervention decision-making system based on a health diagnosis model, and the system comprises the steps: collecting physical and chemical parameters of a target tree according to a preset position at a fixed time interval; constructing a health diagnosis model: performing cycle fitting processing on the temperature parameters of the daily time sequence to obtain fitting data; respectively determining a phase lag time, a thermal diffusivity and an amplitude ratio based on the fitting data; determining the heat variation of the soil, determining the corrected surface heat flux by combining the heat flux parameters, and extracting the peak value of the daily corrected surface heat flux; performing combined judgment processing on the volumetric water content, the dry density, the phase lag time, the thermal diffusivity and the amplitude ratio to judge whether the target tree is in a false water shortage state or not; in response to the false water shortage state of the target tree, determining the risk level of the target tree according to the peak value of the corrected surface heat flux; and generating an intervention decision scheme based on the risk level of the target tree.

The invention discloses a cutting control method for a steel structure product, which comprises the following steps: collecting data of a steel structure, establishing a three-dimensional stress field according to the collected data of the steel structure, and generating a three-dimensional stress distribution diagram by the three-dimensional stress field; collecting the heat conductivity coefficient and the heat diffusivity of the steel, and establishing a heat conduction model according to the heat conductivity coefficient and the heat diffusivity; identifying a stress sensitive area according to the three-dimensional stress distribution diagram, and planning a cutting path according to the three-dimensional stress distribution diagram and the stress sensitive area; an active heat management system is designed, the active heat management system comprises a temperature sensor, a cooling liquid spraying device and a control system, and heat input and heat dissipation strategies can be more accurately designed by researching stress heat conduction characteristics, so that the phenomena of local overheating and heat stress concentration are reduced.

The present application relates to the technical field of dynamic positioning of steel material local heating cutting, and discloses a steel material cutting positioning system, which comprises a cutting energy source numerical control controller and a thermal signal sensing base station which moves integrally with a workpiece, wherein the actual thermal diffusivity of the workpiece is self-calibrated through double-point inquiry before cutting, and in the cutting, the thermal pulse emitted by the energy source is responded by the base station and the real position is solved through three-side measurement to generate a coordinate offset value to correct the subsequent path in real time, the present application directly establishes the measurement reference on the workpiece body, so that the physical drift and deformation of the workpiece caused by local heating are converted from a continuous cumulative positioning error source into a background condition which is real-time surveyed and internally eliminated in each position solving, thereby solving the problem of dynamic disconnection of the coordinate system.

The present invention is a battery pack having a battery cell, a cooling plate, and a battery case that accommodates the battery cell and the cooling plate, the battery pack being provided with an adhesive sheet that adheres the battery cell and the cooling plate, the adhesive sheet having a reduction rate of thermal diffusivity before and after heating represented by formula (1) of 4.5% or more when the adhesive sheet is heated at 285 DEG C for 5 minutes. ((thermal diffusivity before heating-thermal diffusivity after heating) / thermal diffusivity before heating) * 100... (1) According to the present invention, it is possible to provide a battery pack provided with an adhesive sheet which has both excellent thermal conductivity in general and excellent thermal insulation properties during thermal runaway.

This invention discloses a method and system for quality acceptance of concealed sprinkler installation based on infrared thermal imaging, relating to the fields of building fire protection facility acceptance and non-destructive testing technology. The method includes: modeling and calibration, establishing a material parameter library containing thermal diffusivity, thermal conductivity, and temperature resistance limits, and completing coordinate system alignment and time synchronization; controlled excitation and triggering, applying hot / cold pulses to the pipe network or connecting metal parts where the sprinkler is located and recording the frequency band identifier; acquisition and preprocessing, obtaining infrared image sequences before, during, and after excitation and extracting temporal observation features such as isothermal contour radius, temperature difference response, temperature gradient center, and contour ellipticity; determining update weights based on signal-to-noise ratio, occlusion, and excitation effectiveness, and performing block fusion and recursion with time decay; installation geometry and fastening status estimation, outputting the sprinkler's position, tilt angle, extension amount or elevation, and fastening status indicators within the ceiling plane; compliance judgment and reporting, generating conclusions and rectification suggestions based on threshold-weighted scoring.

A method includes receiving a gas or gas mixture through a flow sensor. A flow velocity, volumetric, or mass flow are determined. The method also includes determining a sound velocity of the gas or gas mixture by an ultrasonic sensor. A density of the gas or gas mixture is correlated from the sound velocity. The method also includes positioning a microthermal sensor in an area with less flow or no flow of the gas or gas mixture. A thermal conductivity and thermal diffusivity of the gas or gas mixture at the one or more temperatures is determined. The method also includes connecting a processor to the microthermal sensor to calculate an energy of the gas or gas mixture based on a calorific value, the temperature and the volume or mass flow. Specific quantities for gas quality are correlated.

The present invention provides a laminated body which is light in weight and has good heat dissipation performance at the same time. The present invention relates to a laminate having at least one metal layer and at least one resin layer, the laminate having a unit weight of 2.0 kg / m2 or less and a thermal diffusivity of 10 * 10-6 m2 / s or more in a direction perpendicular to the lamination direction.

A carbon material is disclosed. The carbon material includes a plurality of stacked carbon atom layers. A proportion of interlayer turbostratic stacking of the plurality of stacked carbon atom layers in the carbon material is greater than or equal to 20%. In-plane thermal diffusivity of the carbon material is greater than or equal to 750 mm2 / s. The proportion of interlayer turbostratic stacking of the carbon atom layers in the carbon material is controlled to be greater than or equal to 20% by a specific process. In this way, the carbon material has high in-plane thermal diffusivity, and can meet a heat dissipation requirement of a device with a high heat flux. The carbon material may be used in an electronic device, a heat dissipation module, a battery system, and a semiconductor structure.

A method of deriving a thermal conductivity value and a thermal diffusivity value for a sample including the steps of providing a sample container comprising a solid annular cylinder of a material with a known thermal conductivity and a known thermal diffusivity, the internal radius of the annular cylinder defining a cylindrical sample space; providing the sample in the cylindrical sample space; applying heat to the sample along the central axis of the cylindrical sample space; taking temperature readings over time in the sample or in the annular cylinder at a first point of known radial distance from the central axis; and using the temperature readings to derive the thermal conductivity value and the thermal diffusivity value.

The invention belongs to the technical field of sensors, and provides a multi-mode tactile sensor, a multi-mode sensing composite robot system and a multi-mode sensing method wherein the multi-mode tactile sensor comprises a first sensing layer, a thermal insulation layer, an autoclave material layer and a second sensing layer which are arranged in sequence; the first sensing layer comprises a first hot film resistor, a first cold film resistor and a first substrate, the first hot film resistor is used for acquiring a first tactile sensing signal, and the first tactile sensing signal comprises at least one of a steady-state signal, a dynamic signal and a sliding signal; the determination module is used for determining at least one of heat conductivity coefficient, thermal diffusivity, roughness, texture and sliding speed; the first cold film resistor is used for acquiring a temperature signal of a to-be-measured substance; the second sensing layer is used for acquiring a pressure signal and an environment temperature signal. According to the multimode touch sensor, the two sensing layers are integrated, detection of pressure and sliding speed can be achieved, and detection of the heat conductivity coefficient, the heat diffusivity, the roughness, the texture and the temperature of a contact substance can be achieved.

This shape-changeable structure comprises a non-deformable part and a deformable part. The non-deformable part has a first stiffness and a first thermal diffusivity. The deformable part is formed continuously with the non-deformable part and has a second stiffness lower than the first stiffness and a second thermal diffusivity lower than the first thermal diffusivity.

The invention belongs to the technical field of testing of physical properties of rock and soil, and particularly relates to a device and a method for testing thermal physical properties of expansive rock and soil, which ensure that a rock and soil sample is in a required humid and hot condition by accurately adjusting the temperature and humidity of an experimental environment. The expansion change of the rock and soil sample is synchronously recorded by acquiring displacement data. And all monitoring data are transmitted to a computer in real time for processing and storage. And the computer analyzes the thermophysical properties (such as heat conductivity coefficient, specific heat capacity, thermal diffusivity and the like) of the rock-soil sample in real time according to the collected data, and finally outputs an accurate test result. The whole working process ensures accurate measurement and efficient test of the thermal physical properties of the expansive rock and soil in a complex humid and hot environment.

The invention provides a non-contact thermal diffusivity measurement method and device of an anisotropic thin film material, and relates to the technical field of thermal diffusivity measurement of thin film materials. The method comprises the following steps: performing beam expansion and shaping on continuously emitted stable laser, and performing dynamic beam shaping and focusing to obtain a laser beam form with variable spatial distribution; meanwhile, the center of the annular heating spot is accurately aligned with the geometric center of the film sample, and the size of the annular heat source is adjusted. A non-contact temperature sensing array is adopted, infrared radiation is synchronously sampled, space-time temperature distribution data of the surface of a film sample is obtained, a thermal simulation algorithm and a machine learning model are input, fitting and dynamic comparison optimization parameters are carried out, and a final anisotropic thermal diffusivity value is obtained through inversion. The method has the advantages of non-contact, quick response, accurate characterization and inversion of in-plane anisotropic thermal diffusivity parameters of the material and the like, and solves the problems of poor sample applicability, local high temperature points, high cost and the like.

The invention relates to a semiconductor chip (100) for determining a thermal conductivity, the thermal diffusivity, the specific heat capacity and secondly a density and / or a viscosity of a gas mixture, comprising: a main body (110); a cantilever cavity (120) surrounded by the main body; an oscillator cantilever (130), which projects into the cantilever cavity (120), and a piezoelectric exciter (131, 132, 133) for exciting vibrations; at least one heater cantilever (140), which projects into the cantilever cavity (120); a heating element (144), in a cantilevered end portion (142); and a temperature sensor element (154, 164); wherein a portion of the cantilever cavity (120) extends between the heating element (144) and the temperature sensor element (154, 164), and wherein at least one portion of the cantilever cavity (120) extends between the heater cantilever (140) and the oscillator cantilever (130); wherein the main body (110) also has a main body web (112) which extends between an oscillator region (123) and a heater region (124) of the cantilever cavity (120), wherein the oscillator cantilever (130) is arranged in the oscillator region (123), and the heater cantilever (140) is arranged in the heater region (124).