CN203502367U

CN203502367U - Device for testing heat conductivity coefficient of material by transient plane heat source method

Info

Publication number: CN203502367U
Application number: CN201320384779.2U
Authority: CN
Inventors: 任静; 张金花; 段恺; 王永艳; 崔新阳; 朱剑飞
Original assignee: Beijing No6 Construction Engineering Quality Test Department Co Ltd; Beijing Building Research Institute Corp Ltd of CSCEC
Current assignee: Beijing No6 Construction Engineering Quality Test Department Co Ltd; Beijing Building Research Institute Corp Ltd of CSCEC
Priority date: 2013-07-01
Filing date: 2013-07-01
Publication date: 2014-03-26
Anticipated expiration: 2023-07-01

Abstract

The utility model relates to a device for testing the heat conductivity coefficient of a material by a transient plane heat source method. The device mainly comprises a probe, a bridge test system, and a data acquisition and analysis system, wherein in the bridge test system, the power supply of a bridge can be adjusted in a range from 0 to 20 V, and the maximum current is not greater than 1 A. The device disclosed by the utility model can be used for measuring various samples, such as block samples, single-axis anisotropic samples, sheet samples and film samples, as well as is high in control accuracy, short in detection cycle, and accurate in test result.

Description

A kind of device of Adsorbent By Using Transient Plane Source Technique test material coefficient of heat conductivity

Technical field

The utility model belongs to material property detection field, is mainly to utilize plane thermal source method of testing to detect structure material coefficient of heat conductivity and thermal diffusion coefficient.

Background technology

Thermal diffusion coefficient and coefficient of heat conductivity are one of main thermal physical property parameters, in the various method of testings of having set up, according to its characteristics of heat transfer, roughly can be summarized as steady state method and Transient Method at present.

Steady state method refer on sample to be tested Temperature Distribution reach stable after, when Temperature Distribution is time-independent stable temperature field in sample, by mensuration, flow through the method that the parameters such as the heat of sample and thermograde are carried out the coefficient of heat conductivity of Calculating material.It is to utilize in steady heat transfer process, and rate of heat transfer equals the equilibrium condition of rate of heat dispation and carrys out heat conducting coefficient measuring.Steady state method has that principle is clear, model is simple, can accurately directly obtain the advantages such as thermal conductivity absolute value, and is suitable for the measurement of wider warm area; Shortcoming is that experiment condition is harsh, Measuring Time is longer; In steady state method, in order to obtain hot-fluid accurately, need the adiabatic condition of strict guarantee test macro, set up compensating heater and increase Insulation, to reduce edge thermal loss; Steady state method is mainly used in measuring the coefficient of heat conductivity of solid material in addition, and it can be run into very large difficulty for studying wet stock, because sample can guarantee that certain temperature field causes the variation of water capacity due to long-time, this will cause the measurement result of coefficient of heat conductivity incorrect.

Development along with new material, requirement to test speed improves greatly, and because the diversity of new material, the parameter that traditional method obtains can not accurately reflect the character of material, traditional model can not accurately reflect the process that will study, so widespread use Transient Method.Transient Method refers to specimen temperature temporal evolution in experiment measuring process, by measuring some the some situation of temperature variation and parameter of some other needs in sample, thereby the method for determining sample coefficient of heat conductivity, the starting point of its analysis is non-Steady Heat-Conduction Differential Equation of Hollow.The test of the utility model Main Basis Adsorbent By Using Transient Plane Source Technique.In transient test method, the Temperature Distribution in sample is time dependent Unsteady Temperature Field, by the speed of test sample temperature variation, just can measure the thermal diffusivity of sample, thereby obtains the coefficient of heat conductivity of sample.The material that has thermal resistance due to employing is simultaneously as thermal source and temperature sensor, and transient state plane technology of heat source can cover larger thermal conductivity scope, thereby can be applicable to various dissimilar materials simultaneously.

Summary of the invention

The purpose of this utility model is to provide a kind of several samples of can measuring as bulk sample, uniaxial anisotropy sample, thin slice sample, film sample, and control accuracy is high, sense cycle is short, the test result proving installation of material thermal conductivity and thermal diffusion coefficient accurately.

The purpose of this utility model is to be achieved through the following technical solutions:

The utility model mainly comprises probe, bridge test system, data acquisition and analytic system (seeing Fig. 1); Described probe inside is double-spiral structure, and resistance value is between 1 Ω-50 Ω, by the thick sheet metal etching of 10 (± 2) μ m, is formed, and the insulation film that both sides are 7 μ m-100 μ m by thickness wraps up, and diameter D is between 4mm-100mm.Sheet metal selection temperature coefficient of resistivity is high, nickel and the molybdenum of good stability; Insulation film should select polyimide, mica, aluminium nitride and aluminium oxide etc. can ignore the material of thermal capacity according to serviceability temperature.The temperature measuring equipment of probe can accurately be responded to the temperature information of sample.The width of double-spiral structure spiral line source should equate with its spacing, and probe diameter is that the double-stranded spacing between 4mm-15mm should be (0.2 ± 0.03) mm; The double-stranded spacing of other diameter probes should be (0.35 ± 0.05) mm.

By probe placement in the middle of two samples, form the structure of similar sandwich, to probe, apply constant dc, after probe heat release, sample interior produces dynamic temperature field, detecting head surface produces temperature rise simultaneously, the resistance of now popping one's head in increases, and makes bridge test system Central Plains balanced bridge unbalance, produces potential change amount.By recording the not variable quantity of electrical quantity in the same time of test period, calculate the temperature time dependent function that rises in value.By to the matching of function curve with calculate coefficient of heat conductivity and the thermal diffusion coefficient of sample.

Described bridge test system (seeing Fig. 2), the power supply of electric bridge should regulate within the scope of (0-20) V, and maximum current is no more than 1A.In bridge system, probe and lead-in wire thereof and resistance R s are in series, and wherein the initial resistivity value of Rs resistance value and probe and lead-in wire thereof (Ro+RL) is close, and remains unchanged in test process.Digital voltmeter is connected between probe and resistance R s, and resistance should be greater than probe resistance and Rs resistance value and 100 times, resolution should reach 6.5 numerical digits, is the integral multiple of power cycle variation.

Described data acquisition and analytic system can show, automatically gather, analyze each electrical quantity, time parameter, and m-temperature rise curve figure can simulate time, finally calculate test result, and this system comprises test operation and data analysis software.Measuring sonde resistance variation with temperature in test, determines that the thermal diffusion coefficient of sample and the computation process of coefficient of heat conductivity are completed automatically by software.Before deal with data, need to cast out corresponding data of some times; the number of casting out is a little relevant with the size of the thermal contact resistance of probe with thickness and the sample of probe protective seam; according to actual conditions, take the circumstances into consideration to choose; but the number of point can not be less than 100, to guarantee the generality of thermal diffusion coefficient and coefficient of heat conductivity.By the rise in value linear relationship (seeing Fig. 3) of time dependent function and dimensionless characteristic time function of sample surface temperature in least square fitting measuring process, finally draw coefficient of heat conductivity.

Accompanying drawing explanation

Fig. 1 is total system structure sketch, wherein 1-main frame (comprising bridge circuit, out-put supply, computing machine and digital voltmeter); 2-specimen mounting; 3-sample bin; 4-probe; 5-sample; 6-radiator valve;

Fig. 2 is bridge test system diagram, wherein R _s-resistance in series; R _lthe all-in resistance of-probe lead wire; R ₀-probe initial resistance; The resistance that Δ R-probe increases in test; Δ U-potential change amount; W-pot;

Fig. 3 is temperature increment and time linear relationship chart.

Embodiment

According to embodiment, the utility model is described in further detail below.

The utility model mainly comprises probe, bridge test system, data acquisition and analytic system, described probe inside is double-spiral structure, resistance value is between 1 Ω-50 Ω, in bridge system, probe and lead-in wire thereof and resistance R s are in series, wherein the initial resistivity value of Rs resistance value and probe and lead-in wire thereof (Ro+RL) is close, and remains unchanged in test process.In bridge test system, the power supply of electric bridge should regulate within the scope of (0-20) V, and maximum current is no more than 1A.

By probe placement in the middle of two samples, form the structure of similar sandwich, according to total testing time and output power, to probe, apply constant dc, after probe heat release, sample interior produces dynamic temperature field, and detecting head surface produces temperature rise simultaneously, and the resistance of now popping one's head in increases, make bridge test system Central Plains balanced bridge unbalance, produce potential change amount.By recording the not variable quantity of electrical quantity in the same time of test period, calculate the temperature time dependent function that rises in value.By to the matching of function curve with calculate coefficient of heat conductivity and the thermal diffusion coefficient of sample, in test process, potentiometric sliding contact should not adjusted.

Claims

1. the device of an Adsorbent By Using Transient Plane Source Technique test material coefficient of heat conductivity, comprise probe, bridge test system, data acquisition and analytic system, it is characterized in that, in bridge test system, probe and lead-in wire thereof and resistance R s are in series, wherein the initial resistivity value Ro+R of Rs resistance value and probe and lead-in wire thereof _lclose, digital voltmeter is connected between probe and resistance R s; Probe inside is double-spiral structure, and resistance value is between 1 Ω-50 Ω, by the thick sheet metal etching of 10 (± 2) μ m, is formed, and the insulation film that both sides are 7 μ m-100 μ m by thickness wraps up, and diameter D is between 4mm-100mm.