Device and method for measuring phase change latent heat of composite phase change energy storage material

Abstract

The invention discloses a device and a method for measuring phase change latent heat of a composite phase change energy storage material, and belongs to the technical field of test of building materials. Obvious shortcomings of small using amount of samples, large error, low representativeness and the like exist in the conventional method for measuring the thermal performance of a composite phase change material. The invention discloses a device for measuring the phase change latent heat of the composite phase change energy storage material and provides a corresponding measurement method. The invention is characterized in that a large quantity of phase change materials are heated by disk-type resistance wires under the condition that the heat of a constant-temperature water bath is preserved; and a curve of the temperature changed along with the time is measured by a plurality of groups of thermocouples and subjected to regression analysis, so that the thermal performance of the composite phase change material can be reflected really. The device and the method have great significance for popularization and application of the composite phase change material, particularly for building energy conservation.

Description

technical field [0001] The invention belongs to the technical field of building material testing. Specifically, it is a device and method for measuring phase change latent heat of phase change energy storage materials. The method is scientific in principle, simple and convenient to test, and the result can accurately reflect the magnitude of phase change latent heat of composite phase change materials. Background technique [0002] Phase change material PCM (phase change material) uses its phase change latent heat to store and release heat, which has the characteristics of small phase change temperature, high heat storage and release density, wide selection of phase change temperature and remarkable energy saving effect. Combining phase change materials with traditional building materials (such as cement, gypsum, etc.) and applying them to building envelopes can improve the energy-saving effect of buildings, significantly reduce temperature fluctuations, and improve the comf...

AI Technical Summary

Problems solved by technology

In practical applications, it is necessary to select a phase change material with a suitable phase change temperature and latent heat of phase change, and it should have excellent durability after being combined with building materials. At present, single-component phase change materials can no longer meet the requirements, and many of them are widely used. composite phase change material

[0003] However, there is no scientific and accurate method to measure the phase change latent heat of composite phase change materials. People can only use the traditional differential scanning calorimetry (DSC) measurement. The principle is to use the compensation method to establish the heat flow with temperature or time. However, this method has the following significant shortcomings: the sampling amount of the DSC method is very small (1mg-50mg), the representativeness is poor, and the test sample cannot reflect the composition of the composite phase change material, but actually only reflects the composition of the composite phase change material. Local composition, so it does not reflect the overall thermal properties of the material well

In addition, there are also a small number of research reports that use the water bath heating method to measure the phase change latent heat of composite phase change materials. However, due to the small thermal conductivity of composite phase change materials, the uniform heating of phase change materials cannot be guaranteed, and the accuracy of the measurement results is also limited. question

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