An experimental instrument for measuring thermal conductivity of materials by solar energy and its measuring method

Abstract

The invention discloses a solar energy measuring material heat conductivity coefficient experimental device and a measuring method thereof. The solar energy measuring material heat conductivity coefficient experimental device comprises a slideway, a heating disc frame, a heat dissipating disc frame, a poor conductor sample frame, a poor conductor sample, a metal sample, a metal sample frame, a heating disc, a heat dissipating disc, a first temperature sensor, a second temperature sensor, a heat dissipation fan, a single chip computer temperature measurement and controller, a compression bolt,a compression nut and a solar photovoltaic power supply system. The measuring device is used for measuring the heat conductivity coefficient of poor conductors and metal materials by utilizing a steady state method. The device is intuitionistic in phenomenon, accurate in measurement data, small in measurement error and good in repeatability, the components are convenient to dismount and mount, thus tests can be conducted smoothly, and the problem that an existing instrument is inconvenient to dismount and mount so that the teaching progress can be slow is avoided. The device improves the testprecision and test efficiency, and can be widely applied to scientific research, education and production.

Description

technical field [0001] The invention specifically relates to an experimental instrument for measuring thermal conductivity of materials by solar energy and a measuring method thereof, belonging to the field of physical experimental instruments. Background technique [0002] Thermal conductivity is a physical quantity that characterizes the thermal conductivity of a substance; changes in the structure of materials and differences in impurities have a significant impact on the value of thermal conductivity of materials, so the thermal conductivity of materials often needs to be specifically determined by experiments; [0003] The common experimental method for measuring thermal conductivity is the steady-state method; first, the sample is heated by a heat source, and the temperature difference inside the sample makes the heat conduct from high temperature to low temperature, and the temperature of each point inside the sample will change with the influence of heating speed and ...

AI Technical Summary

Problems solved by technology

[0005] (1) Existing experimental instruments are mostly used to measure the thermal conductivity of poor conductors (such as rubber glass, ceramics, plexiglass, plastics), and cannot accurately measure the thermal conductivity of metal materials (such as copper, aluminum, iron, etc.); measurement content Single, unable to meet the needs of an instrument that can accurately measure the thermal conductivity of poor conductors and metals at the same time;

[0006] (2) When the FD-TC-B thermal conductivity tester is in use, the sample needs to be placed between the heating plate and the cooling plate. The sample is required to be completely aligned with the heating plate and the cooling plate, and then fixed; then adjust the bottom three A fine-tuning screw to make the sample in good contact with the heating plate and heat dissipation plate, but be careful not to be too tight or too loose: too tight will compress the thickness of the sample, and too loose will cause poor contact between the sample and the heating plate and heat dissipation plate, and there is an air gap in the middle; These will lead to the inability to accurately measure the thermal conductivity of the sample; the control of the bonding degree of the contact surface of the existing equipment is not flexible, and it cannot be well adjusted so that the sample is in good contact with the heating plate and the cooling plate;

[0007] In the experiment, the heating plate, the disc sample, and the cooling plate have the same circular area, and they are stacked together from top to bottom. The sample is required to be completely aligned with the heating plate and the cooling plate. It is inconvenient to completely align the heating plate, sample, and heat dissipation plate; then adjust the three fine-tuning screws at the bottom to make the sample contact with the heating plate and heat dissipation plate; when adjusting the three fine-tuning screws at the bottom, the heating plate and the disc sample 1. The heat dissipation plate is easy to tilt, causing the heating plate, the disc sample, and the heat dissipation plate to be misaligned with each other, and cannot be completely aligned, which affects the experimental measurement. A little carelessness will lead to inaccurate measurement results, and the entire installation and adjustment process is cumbersome; in addition , When replacing the sample, it is necessary to remove or raise the heating plate and the electric heater on the heating plate to replace the sample. It is easy to be burned during operation, and the operation is not flexible; when calculating the thermal conductivity, it is necessary to measure the radius and thickness of the heat sink. The radius and thickness of the sample; therefore, it is necessary to remove the cooling plate and the sample for measurement, and it is inconvenient to install and disassemble the existing equipment; the disassembly and assembly of the equipment in the whole experiment is not easy enough, which leads to the unsmooth experiment, which wastes the limited teaching experiment time and delays teaching progress;

[0008] (3) Steady-state method to measure the thermal conductivity of bad conductors and metal materials. In the experiment, the bad conductor needs to be set as a circular plate with a diameter of 10cm and a thickness of 10mm; the metal needs to be set as a cylinder with a length of 20cm and a cross-sectional diameter of 10cm ; One end of the sample is in full contact with a stable uniform heating body, and the other end is in contact with a uniform heat sink; the bad conductor is a flat sample, and its side area is much smaller than the flat plane, so it can be considered that the heat is only perpendicular to the direction of the flat plane transfer, the heat dissipated from the side can be ignored, that is, it can be considered that there is only a temperature gradient in the sample in the direction perpendicular to the sample plane, and in the same plane, the temperature everywhere is the same; while the side area of ​​the metal sample is compared with the flat plane The difference is not big or even larger than the plane area of ​​the flat plate, and the heat dissipated from the side will greatly affect the measurement results;

[0009] (4) The FD-TC-B thermal conductivity tester does not have an electronic timer, and it is equipped with timers such as stopwatches, electronic watches, mobile phones, etc. The inconsistent timers cause timing errors;

[0010] (5) The FD-TC-B thermal conductivity tester adopts electric heating method, which consumes electricity and completely depends on the power supply from the external power grid, and cannot be used when the power is off;

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