Device for measuring liquid heat conductivity coefficient based on transient dual-hot-wire method

Abstract

The invention discloses a device for measuring liquid heat conductivity coefficient based on a transient dual-hot-wire method. The device needs short time for measurement, and can successfully avoid influence of natural conversion on a test result. Hot wires in the device can serve as both heating elements and temperature measuring elements, a complex structure of experimental devices is omitted, meanwhile, a thermal conductivity cell is endowed with a steady water bath temperature environment, and the device has high measurement accuracy. According to the invention, a thermal conductivity cell insulation barrel device, a glass test tube and a hot wire loading device are independently designed. By a series of processes that a low-temperature thermostat bath serves as a temperature controller so as to provide the constant water bath environment, a direct current calibrator serves as a power supply for measurement, a Wheatstone bridge measures the relation between the temperature variation and the resistance, and a data acquisition control unit serves as a data acquisition instrument for the unbalanced voltage of the Wheatstone bridge, the rate of change of the unbalanced voltage along with time is obtained, and sequentially, the liquid heat conductivity coefficient is solved.

Description

Technical field [0001] The invention relates to the technical field of liquid thermal conductivity measurement, in particular to a device for measuring liquid thermal conductivity based on a transient double hot wire method. Background technique [0002] Thermal conductivity is an important transport property of liquids, and is the main parameter reflecting the heat transfer capacity of the medium. It is indispensable in heat transfer design. At present, the theoretical research on thermal conductivity has not yet entered the practical stage, and the existing empirical correlations cannot be widely adapted to the needs of the site, so the thermal conductivity of liquids is mainly measured through experiments. [0003] Since most experiments for measuring thermal conductivity use metal copper rods as samples, and the thermal conductivity of liquids is small, it is basically a poor thermal conductor, and its thermal conductivity is difficult to measure. More importantly, the liquid ...

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Problems solved by technology

However, the device based on this principle (CN200920199015) cannot ensure that the hot wire is in the center of the thermal conductivity pool and the platinum wire is in a tight state, which will affect the distribution of the temperature field in the thermal conductivity pool, thereby causing deviations in the test results

At the same time, this type of device cannot accurately guarantee the constant temperature environment of the heat conduction pool, and the heat conduction pool is directly placed in the constant temperature water tank, which makes the accuracy of the test results poor and affects the usable range of the device

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