JP2006071565A - Method and apparatus for testing heat insulation performance of heat insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test method and a test apparatus which can easily determine the heat insulation performance of a heat insulating material having an overall heat transfer coefficient of not larger than 50 W/m<SP>2</SP>K. <P>SOLUTION: The heat insulation performance of the heat insulating material is determined from the temperature difference between the heat source contact surface of the heat insulating material 5, which is in contact with a heat source 4 at a prescribed temperature, and a plane facing the heat source contact surface, and from the correlation between temperature differences of two surface sides of the heat insulating material and the overall heat transfer coefficient of the heat insulating material 5, calculated by using its heat transfer coefficient and the ambient temperature of the testing conditions. Thus, such a determination can be made, by using the temperature differences that the overall heat transfer coefficient is not larger than a prescribed value, and the heat insulation performance of the heat insulating material 5 can be tested. Furthermore, since only the temperatures are measured, the test can be carried out in a short time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inspection method for inspecting whether or not a heat insulating material has a predetermined heat insulating performance, and an inspection apparatus for executing the inspection method.

  A conventional inspection apparatus obtains a thermal conductivity by controlling the temperature of both surfaces of an object to be measured to create a temperature difference, and measuring a heat flux, a temperature difference, and a thickness.

  In addition, heat is generated between the object to be measured and the heat resistance material to flow heat inside the object to be measured and the heat resistance material, and the thermal conductivity of the object to be measured is determined from the temperature difference between at least two locations of the heat resistance material. There is also a device for obtaining (see, for example, Patent Document 1).

  FIG. 4 is a schematic cross-sectional view of a conventional thermal conductivity measurement method described in Patent Document 1. As shown in FIG. 4, the device includes a device under test 1, a heat resistance material 2, and a heat generator 3.

  The operation of the inspection apparatus configured as described above will be described below.

First, heat is supplied from the heat generating device 3 to the device under test 1 and the heat resistance material 2, and the thermal conductivity of the device under test 1 is obtained from the temperature difference between at least two locations of the heat resistance material 2.
JP 2002-131257 A

  However, in the conventional configuration described above, there is a problem that an object to be measured with low thermal conductivity cannot be measured if the heat flux sensor is small in terms of accuracy of the heat flux sensor. There was a limit to the size of the object to be measured.

  Further, in the configuration of Patent Document 1, it is necessary to measure the temperature of at least two places on one side of the object to be measured. In order to increase the measurement accuracy, it is necessary to measure several temperatures over a certain distance. . For this reason, there is a problem that the measurement accuracy is lowered when the object to be measured is small. Further, in order to obtain the thermal conductivity from the temperature difference between the two locations, it is necessary to actually measure the relationship between the temperature difference between the two locations on the object to be measured and the thermal conductivity. For this reason, there is a problem that the number of measurement steps increases.

This invention solves the said conventional subject, and provides the test | inspection method and test | inspection apparatus which can determine easily the heat insulation performance of the heat insulating material of the heat transmissivity of 50 W / m < ² > K or less especially. .

  In order to solve the above-described conventional problems, the inspection apparatus of the present invention measures the temperature difference by attaching a temperature difference to the back surface of the heat insulating material.

  As a result, the correlation between the temperature difference and the heat flow conductivity can be derived from (Equation 1) without actually measuring the relationship between the temperature difference and the heat flow rate beforehand. It is possible to more easily determine, and it is possible to easily determine the heat insulation performance of the heat insulating materials having various thermal conductivities, shapes, and sizes.

  The inspection apparatus of the present invention can easily determine the heat insulating performance of heat insulating materials having various thermal conductivities, shapes, and sizes.

  According to the first aspect of the present invention, the temperature difference between the heat source contact surface of the heat insulating material in contact with the heat source at a predetermined temperature and the surface facing the surface, the thermal conductivity of the heat insulating material calculated in advance, the heat insulating material surface and the back surface Therefore, the temperature difference between the front and back surfaces of the heat insulating material is determined by the correlation between the thermal conductivity and the temperature difference between the two surfaces. By measuring the difference, it can be determined from the temperature difference that the heat reflux rate is a predetermined value or less, and the heat insulating performance of the heat insulating material can be inspected. Moreover, since only temperature is measured, it can test | inspect in a short time.

  The invention according to claim 2 is a heat insulation calculated from a temperature difference between a heat source contact surface of a heat insulating material in contact with a heat source having a predetermined temperature and a surface facing the surface, an ambient temperature of an inspection condition, and a heat transfer coefficient. Because it is an inspection method to determine the heat insulation performance of the heat insulating material from the correlation between the heat transmissivity of the material and the temperature difference between the heat insulating material surface and the back surface, from the correlation between the heat flow rate and the temperature difference between the heat insulating material surface and the back surface By measuring the temperature difference between the two surfaces of the heat insulating material and measuring the temperature difference between the two surfaces, it can be determined from the temperature difference that the heat reflux rate is a predetermined value or less, and the heat insulating performance of the heat insulating material can be inspected. it can.

  Moreover, since only temperature is measured, it can test | inspect in a short time. In addition, since the correlation between the heat transmissibility and the temperature difference between the front and back surfaces of the heat insulating material is uniquely determined if the ambient temperature and the heat transfer coefficient in the inspection conditions are the same, there is no need to obtain correlation data in advance. Can be shortened.

Invention of Claim 3 is the inspection method of Claim 1 or Claim ² whose heat transmissivity of a heat insulating material is 50 W / m < ² > K or less, and is the insulation method surface and back surface with respect to heat transmissivity. Since the gradient of the temperature difference is large, the inspection accuracy is improved.

  Invention of Claim 4 is a test | inspection method as described in any one of Claims 1-3 whose thickness of a heat insulating material is 5 mm or less, and is the temperature of the heat insulating material surface and back surface with respect to a heat transmissivity. Since the gradient of the difference is large, the inspection accuracy is improved. Moreover, the inspection time can be shortened by being thin.

  Invention of Claim 5 is an inspection apparatus provided with the means to perform the inspection method of any one of Claims 1-4, and can test | inspect heat insulation performance.

  The invention described in claim 6 is provided with a temperature sensor that measures the ambient temperature, and corrects correlation data of the thermal transmissivity and the temperature difference between the heat insulating material surface and the back surface from the measured data. This is an inspection device that measures the ambient temperature, knows the temperature at the time of measurement, and corrects the correlation data between the thermal conductivity and the temperature difference between the two surfaces. Since the difference between the temperature difference and the actual temperature difference can be reduced, the inspection accuracy can be improved.

  The invention according to claim 7 is the inspection apparatus according to claim 5 or claim 6 in which the inspection apparatus is covered with a case, and since the heat transfer coefficient can be made constant, the thermal conductivity that can be calculated from (Equation 1). Since the correlation between the temperature difference between the front surface and the back surface of the heat insulating material and the difference between the actually measured temperature can be reduced, the inspection accuracy can be improved.

  The invention according to claim 8 is the inspection apparatus according to any one of claims 5 to 7, wherein two or more temperature sensors are provided on at least one side of the heat insulating material, and the temperature is measured at two or more points. By doing so, it is possible to reduce measurement temperature variations due to steps on the surface of the heat insulating material and variations such as density differences, so that inspection accuracy can be improved.

  Invention of Claim 9 is an inspection apparatus as described in any one of Claim 5-8 provided with the sensor which measures the thickness of a heat insulating material, and extracts the heat insulating material of the thickness outside a product specification. Inspection efficiency is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram of a measurement unit of the inspection apparatus according to Embodiment 1 of the present invention. FIG. 2 is a correlation diagram between the heat transmissivity and the temperature difference between both surfaces of the heat insulating material in Embodiment 1 of the present invention. FIG. 3 is a correlation diagram between the thermal conductivity and the temperature difference between both surfaces of the heat insulating material in Embodiment 1 of the present invention.

  1, 2, and 3, the measurement unit 8 of the inspection apparatus is sandwiched from the case 7 that prevents the influence of wind, the heat source 4 that is in contact with one surface of the heat insulating material 6 to control the temperature, and the other surface of the heat insulating material 6. It comprises a temperature sensor 6 that includes a heat sink 9 and measures the temperature of the heat source contact surface of the heat insulating material 6 and the surface facing the surface. In addition, correlation data between the temperature difference and the heat transmissivity calculated from (Equation 1) by inputting the ambient temperature and the heat transfer coefficient in advance, or data on the correlation between the temperature difference and the heat transmissivity is provided.

In addition, a sensor for measuring the thickness of the heat insulating material 5 at the same time as the temperature measurement is preferably provided, and the function of converting the heat transmissivity into the thermal conductivity is obtained based on the thickness. In addition, a sensor for measuring the ambient temperature is provided. Further, the temperature sensor 6 is preferably provided with at least two points on one side of one heat insulating material 5. Further, the thermal conductivity of the heat insulating material is preferably 50 W / m ² K or less. Moreover, the thickness of the heat insulating material is preferably 5 mm or less. The operation of the inspection apparatus configured as described above will be described below.

  The temperature of one surface of the heat insulating material 5 is controlled by the heat source 4, the temperature of the front surface and the back surface of the heat insulating material 5 is measured by the temperature sensor 6, and a temperature difference is obtained. Based on the correlation between the measured temperature difference and FIG. 2, it can be determined from the temperature difference that the heat reflux rate is equal to or less than a predetermined value.

  As described above, in the present embodiment, the temperature difference between the heat source contact surface of the heat insulating material 5 in contact with the heat source 4 at a predetermined temperature and the surface facing the surface, the ambient temperature and the heat transfer coefficient of the inspection conditions Since the heat insulation performance of the heat insulating material is determined from the correlation between the heat transmissivity of the heat insulating material 5 calculated and the temperature difference between the heat insulating material surface and the back surface, it is determined from the temperature difference that the heat reflux rate is a predetermined value or less. The heat insulating performance of the heat insulating material 5 can be inspected.

  Moreover, since only temperature is measured, it can test | inspect in a short time. In addition, since the correlation between the heat transmissibility and the temperature difference between the front and back surfaces of the heat insulating material is uniquely determined if the ambient temperature and the heat transfer coefficient in the inspection conditions are the same, there is no need to obtain correlation data in advance. Can be shortened.

Also, if the thermal conductivity of the heat insulating material is 50 W / m ² K or less, as can be seen from FIG. 2, the inclination of the temperature difference between the heat insulating material surface and the back surface with respect to the thermal flow rate is large, so the inspection accuracy is improved. Also, if the thickness of the heat insulating material 5 is 5 mm or less, the temperature difference between the heat insulating material surface and the back surface with respect to the thermal conductivity is large as seen from FIG. 3 (Table 1) with the thickness factor added to FIG. Inspection accuracy is improved, and inspection time can be shortened by being thin.

また、風による影響を減らすケース７を備えており、熱伝達率が一定になることで（数１）より算出できる熱貫流率と断熱材表面と裏面との温度差の相関関係と実測温度差との差を少なくできるので、検査精度を向上できる。

Moreover, the case 7 for reducing the influence of wind is provided, and the correlation between the heat transmissibility that can be calculated from (Equation 1) and the temperature difference between the front and back surfaces of the heat insulating material and the actually measured temperature difference when the heat transfer coefficient becomes constant. Inspection accuracy can be improved.

  Further, since the thickness can be measured, the accurate thickness of each heat insulating material 5 can be known, and a heat insulating material having a thickness outside the product standard can be extracted, thereby improving inspection efficiency. Further, since the ambient temperature can be measured, the difference between the measured thermal difference and the correlation between the heat transmissibility calculated from (Equation 1) and the temperature difference between the front and back surfaces of the heat insulating material can be reduced, and the inspection accuracy can be improved.

  In addition, by using a plurality of temperature sensors 11 for each measurement point, it is possible to reduce the measurement temperature variation due to variations in the surface step of the heat insulating material 5 and the density difference of the heat insulating material 5, and to improve inspection accuracy. Can do. In addition, in this Embodiment, although the heat radiator 9 is made to contact the single side | surface of the heat insulating material 5, it can also be changed to air. By changing to air, the time until the measurement temperature is stabilized is shortened, and the inspection efficiency is improved. Moreover, although the heat transmissivity is used in the correlation, this is one index indicating heat, and the same can be done even if this is heat conductivity, heat flow rate, or the like.

  As described above, the inspection apparatus according to the present invention shows that the thermal conductivity is within a predetermined range by making a temperature difference on both surfaces of the heat insulating material and measuring the temperature on both surfaces, thereby reducing the heat insulating performance of the heat insulating material. Since it is possible to easily inspect in time, it can be applied to inspection on the production line of vacuum heat insulating material.

Schematic diagram of measuring unit of inspection apparatus according to Embodiment 1 of the present invention The characteristic view which shows the correlation with the heat flow rate in Embodiment 1 of this invention, and the temperature difference of both surfaces of a heat insulating material. The characteristic view which shows the correlation with the heat conductivity in Embodiment 1 of this invention, and the temperature difference of both surfaces of a heat insulating material Schematic diagram of conventional inspection equipment

Explanation of symbols

4 Heat source 5 Heat insulation 6 Heat source 7 Case

Claims (9)

  From the correlation between the temperature difference between the heat source contact surface of the heat insulating material in contact with the heat source at a predetermined temperature and the surface facing the surface, and the temperature difference between the thermal conductivity of the heat insulating material calculated in advance and the surface of the heat insulating material and the back surface An inspection method for determining the heat insulation performance of a heat insulating material.   The heat transmissivity of the heat insulating material and the surface of the heat insulating material calculated from the temperature difference between the heat source contact surface of the heat insulating material in contact with the heat source of the predetermined temperature and the surface facing the surface, the ambient temperature and the heat transfer coefficient of the inspection conditions Inspection method to determine the heat insulation performance of the heat insulating material from the correlation of the temperature difference between the back surface and the back surface. The inspection method according to claim 1 or 2, wherein the thermal conductivity of the heat insulating material is 50 W / m ² K or less.   The inspection method according to any one of claims 1 to 3, wherein a thickness of the heat insulating material is 5 mm or less.   An inspection apparatus comprising means for executing the inspection method according to any one of claims 1 to 4.   The inspection apparatus according to claim 5, further comprising a temperature sensor that measures an ambient temperature, and correcting correlation data of a thermal transmissivity and a temperature difference between a heat insulating material surface and a back surface from the measured ambient temperature.   The inspection apparatus according to claim 5 or 6, wherein the inspection apparatus is covered with a case.   The inspection apparatus according to any one of claims 5 to 7, wherein two or more temperature sensors are provided in at least one side of the heat insulating material in the data processing unit.   The inspection apparatus according to any one of claims 5 to 8, further comprising a sensor for measuring a thickness of the heat insulating material.

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