JP2009069079A - Estimation method of temperature in material, method and device for estimating heat flux and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate the temperature in a material without supposing the initial temperature in a container wall. <P>SOLUTION: An accurate solution is calculated by one operation by executing the following processes: the process for measuring the outer wall temperature of a material to be measured; the process for calculating the heat moving characteristic value of the material to be measured; the noise removing process for removing the noise components in the outer wall temperature measured value, which is calculated in the outer wall temperature measuring process, and in the heat moving characteristic value, which is calculated in the heat moving characteristic value calculation process, using a noise removing algorithm using a Legendre polynomials; the process for calculating the high-order differential coefficients of the outer wall temperature measured value and the heat moving characteristic value from which the noise component is removed in the noise removing process; and the calculation process for calculating an internal temperature using the high-order differential coefficient calculated in the differential coefficient calculation process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a temperature estimation method inside a material, a heat flux estimation method, an apparatus, and a computer program, and in particular, used to estimate the temperature and heat flux inside a material having a temperature difference between an inner surface and an outer surface. It relates to a suitable technique.

Knowing the temperature or heat flux inside the material based on the temperature and heat flux measured on the surface of the outer wall of the material is very important from the following viewpoints.
That is, (1) To determine the heating state and cooling state of the material. (2) In order to determine the state of a phenomenon occurring inside the apparatus based on the inner surface temperature and inner surface heat flux of the apparatus material. (3) To determine the remaining thickness of the device material wall.

  In order to achieve the above-mentioned objectives (1) to (3), etc., until now, the heat conduction phenomenon inside the container wall is considered as an unsteady heat conduction inverse problem and measured by the temperature measuring means installed on the container wall. The calculation was based on the measured temperature data.

  Specifically, a method for estimating the thickness of the container wall by calculating the temperature inside the container wall using an unsteady heat conduction inverse problem and searching for a position where the temperature of the container wall matches the solidification temperature of the molten iron has been proposed. (For example, refer to Patent Document 1).

JP 2001-234217 A

  However, in the inverse problem analysis disclosed in Patent Document 1, the thickness of the container wall is estimated and the calculation is performed assuming the initial temperature inside the container wall. For this reason, if the initial temperature setting is not appropriate, a large error will occur in the temperature calculation result, causing a significant decrease in calculation accuracy. In some cases, the calculation may diverge and the calculation may be interrupted. There was a problem.

The present invention has been made in view of the above points, and a first object of the present invention is to make it possible to estimate the temperature inside the material without assuming the initial temperature inside the container wall.
A second object is to make it possible to estimate the heat flux of the material.

  The method for estimating the temperature inside the material of the present invention includes an outer wall temperature measuring step for measuring the outer wall temperature of the material to be measured, and a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material. Noise removal using the Legendre polynomial for the heat transfer characteristic value calculation step to be calculated, the outer wall temperature measurement value measured in the outer wall temperature measurement step, and the noise component in the heat transfer characteristic value calculated in the heat transfer characteristic value calculation step A noise removing step for removing using an algorithm; a derivative calculating step for calculating a higher order derivative of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step; and the derivative calculating And an internal temperature calculation step of calculating an internal temperature using a high-order derivative calculated in the step.

  The heat flux estimation method of the present invention includes an outer wall temperature measurement step for measuring the outer wall temperature of the material to be measured, and a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material. A noise removal algorithm using a Legendre polynomial for the heat transfer characteristic value calculation step, the outer wall temperature measurement value measured in the outer wall temperature measurement step, and the noise component in the heat transfer characteristic value calculated in the heat transfer characteristic value calculation step A noise removing step for removing the noise using a noise, a derivative calculating step for calculating a higher-order derivative of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step, and the derivative calculating step. A heat flux is obtained using an internal temperature calculation step for calculating an internal temperature using a high-order differential coefficient calculated in step 1 and an equation for calculating the internal temperature in the internal temperature calculation step. And having a flux calculation process.

  The temperature estimation device inside the material of the present invention comprises an outer wall temperature measuring means for measuring the outer wall temperature of the material to be measured, and a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material. Noise removal using a Legendre polynomial for the heat transfer characteristic value calculation means to calculate, the outer wall temperature measurement value measured by the outer wall temperature measurement means, and the noise component in the heat transfer characteristic value calculated by the heat transfer characteristic value calculation means Noise removing means for removing using an algorithm; differential coefficient calculating means for calculating higher-order derivatives of outer wall temperature measurement values and heat transfer characteristic values from which noise has been removed by the noise removing means; and the derivative calculation And an internal temperature calculating means for calculating the internal temperature using a high-order derivative calculated by the means.

  The heat flux estimation apparatus of the present invention calculates an outer wall temperature measuring means for measuring an outer wall temperature of a material to be measured and a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material. A noise removal algorithm using a Legendre polynomial for the heat transfer characteristic value calculating means, the outer wall temperature measurement value measured by the outer wall temperature measurement means, and the noise component in the heat transfer characteristic value calculated by the heat transfer characteristic value calculation means A noise removing unit that removes the noise using the noise removing unit, a derivative calculating unit that calculates a higher-order derivative of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed by the noise removing unit, and the derivative calculating unit An internal temperature calculation means for calculating an internal temperature using a high-order derivative calculated by the above, and a heat flux for obtaining a heat flux using an expression for calculating the internal temperature by the internal temperature calculation means And having a calculation unit.

The computer program of the present invention includes an outer wall temperature measuring step for measuring an outer wall temperature of a material to be measured, and a heat transfer for calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material. The noise component in the characteristic value calculation process, the outer wall temperature measurement value measured in the outer wall temperature measurement process, and the heat transfer characteristic value calculated in the heat transfer characteristic value calculation process, using a noise removal algorithm using a Legendre polynomial. A noise removing step for removing the noise, a differential coefficient calculating step for calculating a higher-order derivative of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step, and a derivative coefficient calculating step. And an internal temperature calculation step of calculating an internal temperature using a higher order differential coefficient.
Another feature of the computer program of the present invention is that the outer wall temperature measuring step for measuring the outer wall temperature of the material to be measured, and the outer wall heat flux of the material to be measured are divided by the thermal conductivity of the material. A heat transfer characteristic value calculation step for calculating a heat transfer characteristic value, an outer wall temperature measurement value measured in the outer wall temperature measurement step, and a noise component in the heat transfer characteristic value calculated in the heat transfer characteristic value calculation step are represented by a Legendre polynomial. A noise removing step for removing using a noise removing algorithm using a noise, a derivative calculating step for calculating a higher-order derivative of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step, and An internal temperature calculation step of calculating an internal temperature using a higher-order differential coefficient calculated in the differential coefficient calculation step; and an internal temperature is calculated in the internal temperature calculation step Characterized in that to execute the heat flux calculation step of calculating the heat flux to the computer using the order of the formula.

According to the present invention, from the temperature measurement data measured at the temperature measurement point on the outer wall surface of the material and the heat flux data calculated based on the temperature measurement data or the heat flux data measured at the temperature measurement point, Temperature can be calculated in a short time.
Also, according to another feature of the present invention, the heat flux of the material can be estimated. As a result, it is possible to accurately estimate the cooling or heating state of the material and the remaining thickness of the apparatus wall.
Further, according to another feature of the present invention, it is possible to obtain a solution in one operation when estimating the cooling or heating state of the material and the remaining thickness of the apparatus wall with high accuracy. Compared with the method described in Document 1, the calculation time can be reduced to 1/10 or less.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, assuming a one-dimensional heat transfer of the material to be measured 100 (for example, a molten steel pan), the time change of the temperature (measured value: f (t)) of the material outer wall is measured.

  In the present embodiment, an example is shown in which a thermocouple 110 is attached to the outer wall of the material to be measured 100 and the outer wall temperature of the material to be measured 100 is measured by the thermocouple 110. And the measured value acquired by the said thermocouple 110 is input into the management apparatus 1300 of a container wall state via the measuring device 120. FIG.

In the present embodiment, an example is shown in which the container wall state management device 1300 is configured by a computer system as shown in FIG.
That is, the container wall state management apparatus 1300 of this embodiment includes a CPU 1301 and executes device control software stored in the ROM 1302 or the hard disk (HD) 1311 or supplied from the flexible disk drive (FD) 1312. Each device connected to the system bus 1304 is collectively controlled.

  Each function unit of the present embodiment is configured by a program stored in the CPU 1301, the ROM 1302, or the hard disk (HD) 1311.

  Reference numeral 1303 denotes a RAM which functions as a main memory, work area, and the like for the CPU 1301. Reference numeral 1305 denotes a keyboard controller (KBC), which controls to input a signal input from the keyboard (KB) 1309 into the system main body. Reference numeral 1306 denotes a display controller (CRTC) which performs display control on the display device (CRT) 1310. A disk controller (DKC) 1307 is a hard disk (boot program (startup program: a program that starts execution (operation) of personal computer hardware and software)), a plurality of applications, editing files, user files, a network management program, and the like. HD) 1311 and flexible disk (FD) 1312 are controlled.

  Reference numeral 1308 denotes a network interface card (NIC) that exchanges data bidirectionally with a network printer, another network device, or another PC via the LAN 1320.

  Next, an example of the processing procedure of the method for estimating the temperature inside the material and the method for estimating the heat flux will be described with reference to the flowcharts of FIGS. In the present embodiment, a temperature estimation method and a heat flux estimation method inside the material are realized using an algorithm called a “power series algorithm”.

As shown in the flowchart of FIG. 2, first, in step S <b> 21, the outer skin wall temperature f (t _i ) of the molten steel pan 60 (see FIG. 6) that is the material to be measured 100 is measured. By this measurement, “f (t _i ) i = 1, 2, 3,..., M” is obtained as the iron skin outer wall temperature measurement value.

Next, in step S22, the heat transfer characteristic value g (ti) of the material to be measured 100 is calculated. This heat transfer characteristic value g (ti) is calculated by dividing the outer wall heat flux by the thermal conductivity of the material. The outer wall heat flux at this time can be estimated and calculated as the sum of radiant heat transfer and convective heat transfer. This estimation formula varies depending on conditions. For example, in the case of a vertical flat plate, the heat flux q [W / m ² K] due to radiation is
q = eσ (T ⁴ −T _a ⁴ )
Where T is the outer wall temperature [K], _Ta is the ambient temperature [K], σ is the Stefan-Boltzmann constant, and e is the emissivity.
The heat flux q [W / m ² K] due to convection is
q = 1.42H ^-0.25 · (T-Ta) ^1.25
However, T is the outer wall temperature [K], T _a c ambient temperature [K], H is the vertical length of the outer wall [m].
The estimation formula is known. Here, the emissivity of radiant heat transfer needs to be determined in advance by experiments. It is also desirable to correct the estimation formula for convective heat transfer in advance by experiments. Through the above calculation, “g (t _i ) i = 1, 2, 3,..., M” is obtained as the heat transfer characteristic value g (ti).

Next, in step S23, noise removal calculation processing is performed on the outer skin wall temperature f (t _i ) and the heat transfer characteristic value g (ti). In the present embodiment, as will be described with reference to the flowchart of FIG. 3, a noise removal operation is performed using a noise removal algorithm called a Legendre polynomial. By performing this noise removal processing, the temperature estimation method and the heat flux estimation method inside the material according to the present embodiment can cope with N-th order time differentiation.

Next, in step S24, a higher-order derivative of the outer wall temperature f (t _i ) and the heat transfer characteristic value g (ti) from which noise has been removed is calculated.
Next, in step S25, the temperature and heat flux of the material to be measured 100 are determined. Details of the arithmetic processing performed in steps S24 and S25 will be described later.

Next, the noise removal processing procedure performed in step S23 will be described with reference to the flowchart of FIG.
First, in step S31, a measurement value is input. Accordingly, “f _i = (t _i ), g _i = g (t _i ), t ₀ <t ₁ <... <T _M ” is input.

Next, in step S32, a noise removal equation is constructed using the Legendre polynomial from the measurement value input in step S31. Details of the noise elimination type configuration will be described later.
Next, in step S33, a process for determining the coefficient a _k used in the noise removal formula in step S32 is performed.
Next, it progresses to step S34 and the process which determines a noise removal type | formula is performed.

Next, the details of the “power series algorithm” used in the present embodiment will be described.
First, “Cauchy data” at “x = 0”

From the equation of heat conduction at x> 0, t> 0

To find a solution u (x, t). Then, the following equation is approximately established by “Taylor expansion” with respect to x of u.

Here, N, which determines the maximum degree of the polynomial, varies depending on conditions, but usually there is an optimum value in terms of accuracy at 5 or less. Next, operator A is

Since u satisfies the heat conduction equation,

Holds. Substituting this into the "Taylor expansion" formula,

Is obtained. The right side can be calculated using numerical differentiation. Further, the following equation for obtaining the heat flux is obtained from this equation.

  Next, the noise removal procedure using the Legendre polynomial will be described.

  As described above, in the present embodiment, the temperature measurement data measured at the temperature measurement point on the outer wall surface of the material, the heat flux data calculated based on the temperature measurement data, or the heat flow measured at the temperature measurement point. From the bundle data, the temperature and heat flux inside the material can be calculated in a short time. Thereby, the cooling state or heating state of the material, and the remaining thickness of the apparatus wall can be accurately estimated.

  Further, according to the present embodiment, when estimating the cooling state or heating state of the material and the remaining thickness of the apparatus wall with high accuracy, it is possible to obtain a solution by a single calculation. Compared with the described method, the calculation time can be reduced to 1/10 or less.

(First embodiment)
The first embodiment of the present invention will be described below with reference to FIGS.
In the first embodiment, an example is shown in which cooling water 101 is allowed to flow through the material to be measured 100 for cooling. In FIG. 4A, the temperature on the front surface side of the material 100 to be measured is measured with the first thermocouple 41, and the temperature on the back surface side is measured with the second thermocouple 42.

  FIG. 4B is a characteristic diagram showing the temperature change of the iron skin outer wall temperature f (ti) measured by the second thermocouple 42, and after 10 seconds have elapsed from the start of measurement, the cooling water 101 The example which flowed is shown. That is, the period of 0 to 10 seconds is atmospheric cooling (cooling), and 10 to 50 seconds is spray cooling. FIG. 4C is a characteristic diagram showing a temperature change of the heat transfer characteristic value g (ti).

  The surface temperature of the material to be measured 100 is measured by the second thermocouple 42, and the measurement data as shown in FIGS. Can be guessed.

FIG. 5 is a characteristic diagram showing an example in which a result measured by the first thermocouple 41 and a result obtained by the arithmetic processing described above are verified. In the arithmetic processing, the positive parameter ε at the time of noise removal was 0.01, the maximum degree L of the Legendre polynomial was 3, and 2 was used as N for determining the maximum degree of the “Taylor expansion”.
FIG. 5A shows a temperature change of the material 100 to be measured on the surface that is spray-cooled. In FIG. 5A, the first characteristic curve denoted by reference numeral 51 indicates the temperature of the cooling surface of the material 100 to be measured actually measured by the first thermocouple 41. A second characteristic curve denoted by reference numeral 52 indicates the calculation result.

  As shown in the characteristic diagram of FIG. 5A, the first characteristic curve denoted by reference numeral 51 almost coincides with the second characteristic curve denoted by reference numeral 52, and the above-described calculation result is accurate. I understood that. FIG. 5B shows the time change of the heat flux. Since this heat flux is difficult to measure, only the calculation results are shown. FIG. 5C shows the result of calculation by changing the heat transfer coefficient (h) in order to obtain a value that is set when the material to be measured 100 is spray cooled.

  As shown in FIG. 5C, it can be seen that the characteristic curve 53 predicted by spray cooling matches the characteristic curve 54 obtained from the calculation result. The heat transfer coefficient (h) and the heat flux q have a relationship of “q = h (Ts−Tw)”. Here, Ts is the temperature of the material 100 to be measured, and Tw is the temperature of the cooling water.

(Second embodiment)
Next, an embodiment of a method for determining the refractory remaining thickness of the molten steel pan 60 will be described.
In the case of this example, it shows about the case where the refractory remaining thickness of the molten steel pan 60 is determined. That is, the wall of the molten steel pan 60 becomes the material to be measured 100 in this embodiment.

  As shown in FIG. 6 (a), the wall of the molten steel pan 60 is composed of an iron skin 60a, a permanent perm brick 60b, a semi-perm brick 60c, a wear brick 60d, and the like. In the present embodiment, the iron skin 60a is measured to obtain the above-described iron skin outer wall temperature f (ti) and the heat transfer characteristic value g (ti). The measurement time is 35 minutes from when 90 minutes have elapsed since the molten steel was charged until 125 minutes have elapsed.

  As shown in FIG. 6 (b), the iron shell outer wall temperature f (t) was about 320 ° C. when 90 minutes passed after the molten steel was charged, but became about 368 ° C. when 125 minutes passed. It is rising.

  Further, as shown in FIG. 6 (c), in the case of the heat transfer characteristic value g (t), it was about 150 when 90 minutes passed from the molten steel charging, but was about when 125 minutes passed. It can be known by calculation that it has risen to 200. When such information is acquired, it is possible to know the relationship between the distance from the iron shell of the molten steel pan 60 and the temperature by calculation using the algorithm described in the above-described embodiment.

In FIG. 7, an example of the relationship between the distance from the iron skin of the molten steel pan 60 and temperature is shown. In the estimation calculation process, the positive parameter ε at the time of noise removal was 0.05, the maximum order L of the Legendre polynomial was 2, and N was used to determine the maximum order of the “Taylor expansion”. In this case, the temperature is converged to a molten steel temperature of 1570 ° C.
As shown in FIG. 7, by calculating using the algorithm described above, the thickness of the iron skin 60a = 32 mm, the thickness of the permanent perm brick 60b = 50 mm, the thickness of the semi-perm brick 60c = 30 mm, and the thickness of the wear brick 60d. = 110 mm can be obtained by calculation.

  As described above, in this embodiment, it is possible to estimate the cooling or heating state of the material and the remaining thickness of the apparatus wall with high accuracy by performing the calculation using the power series algorithm. In addition, when performing these estimations, it becomes possible to obtain a solution by a single calculation. For example, compared with the method described in Patent Document 1, the calculation time is reduced to 1/10 or less. Can do.

  In addition, the temperature estimation apparatus inside the material of the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device.

  The object of the present invention can also be achieved by supplying a computer program for realizing the above-described functions to a system or apparatus and executing the computer (CPU or MPU) of the system or apparatus. In this case, the computer program itself Constitutes the present invention.

It is a figure which shows embodiment of this invention and demonstrates a mode that the outer wall temperature of a to-be-measured material is measured with the management apparatus of a container wall state. It is a flowchart which shows an example of the process sequence of the estimation method of the temperature inside a material, and the estimation method of a heat flux using a power series algorithm. It is a flowchart which shows an example of the process sequence which performs a noise removal calculation using a Legend polynomial. (A) is a figure explaining a mode that the temperature of the to-be-measured material which is spray-cooled is measured with a thermocouple, (b) is the temperature on the opposite side to the surface which is spray-cooled with a thermocouple. It is the characteristic view which showed the temperature change of the iron-skin outer wall temperature f (ti) by measuring, (c) is the characteristic view which showed the temperature change of the heat transfer characteristic value g (ti). (A) is a characteristic diagram showing the temperature change of the material to be measured on the surface being spray-cooled, (b) is a characteristic diagram showing the time change of the heat flux, and (c) is a spray of the material to be measured. It is a characteristic view which shows the result calculated by changing a heat transfer coefficient (h) in order to make it the value set when cooling. The example which determines the refractory remaining thickness of a molten steel pan is shown, (a) is a figure explaining an example of the wall structure of a molten steel pan, (b) is an example of the elapsed time change of an iron-skin outer wall temperature f (t). (C) is a characteristic diagram showing an example of a change in elapsed time of the heat transfer characteristic value g (t). It is a characteristic view which shows an example of the relationship between the distance from the iron skin of a molten steel pan, and temperature.

Explanation of symbols

100 Material to be measured 110 Thermocouple 120 Measuring instrument 1300 Container wall state management device 1301 CPU
1302 ROM
1303 RAM
1304 System Bus 1305 Keyboard Controller (KBC)
1306 Display Controller (CRTC)
1307 Disk controller (DKC)
1308 Network Interface Card (NIC)
1309 Keyboard (KB)
1310 Display (CRT)
1311 Hard Disk (HD)
1312 Flexible Disk Drive (FD)
1320 LAN

Claims (6)

An outer wall temperature measurement process for measuring the outer wall temperature of the material to be measured;
A heat transfer characteristic value calculating step of calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the heat conductivity of the material;
A noise removal step of removing noise components in the outer wall temperature measurement value measured in the outer wall temperature measurement step and the heat transfer characteristic value calculated in the heat transfer property value calculation step using a noise removal algorithm using a Legendre polynomial. When,
A differential coefficient calculating step of calculating a high-order differential coefficient of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step;
An internal temperature calculation step of calculating an internal temperature using a high-order differential coefficient calculated in the differential coefficient calculation step. An outer wall temperature measurement process for measuring the outer wall temperature of the material to be measured;
A heat transfer characteristic value calculating step of calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the heat conductivity of the material;
A noise removal step of removing noise components in the outer wall temperature measurement value measured in the outer wall temperature measurement step and the heat transfer characteristic value calculated in the heat transfer property value calculation step using a noise removal algorithm using a Legendre polynomial. When,
A differential coefficient calculating step of calculating a high-order differential coefficient of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step;
An internal temperature calculation step of calculating an internal temperature using a higher-order derivative calculated in the derivative calculation step;
And a heat flux calculation step of obtaining a heat flux using an equation for calculating the internal temperature in the internal temperature calculation step. Outer wall temperature measuring means for measuring the outer wall temperature of the material to be measured;
Heat transfer characteristic value calculating means for calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material;
Noise removal means for removing a noise component in the outer wall temperature measurement value measured by the outer wall temperature measurement means and the heat transfer characteristic value calculated by the heat transfer characteristic value calculation means using a noise removal algorithm using a Legendre polynomial. When,
Differential coefficient calculating means for calculating higher order differential coefficients of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed by the noise removing means;
An internal temperature calculation means for calculating an internal temperature using a high-order differential coefficient calculated by the differential coefficient calculation means. Outer wall temperature measuring means for measuring the outer wall temperature of the material to be measured;
Heat transfer characteristic value calculating means for calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the thermal conductivity of the material;
Noise removal means for removing a noise component in the outer wall temperature measurement value measured by the outer wall temperature measurement means and the heat transfer characteristic value calculated by the heat transfer characteristic value calculation means using a noise removal algorithm using a Legendre polynomial. When,
Differential coefficient calculating means for calculating higher order differential coefficients of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed by the noise removing means;
An internal temperature calculation means for calculating an internal temperature using a high-order derivative calculated by the derivative calculation means;
An apparatus for estimating a heat flux, comprising: a heat flux calculating means for obtaining a heat flux using an equation for calculating an internal temperature by the internal temperature calculating means. An outer wall temperature measurement process for measuring the outer wall temperature of the material to be measured;
A heat transfer characteristic value calculating step of calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the heat conductivity of the material;
A noise removal step of removing noise components in the outer wall temperature measurement value measured in the outer wall temperature measurement step and the heat transfer characteristic value calculated in the heat transfer property value calculation step using a noise removal algorithm using a Legendre polynomial. When,
A differential coefficient calculating step of calculating a high-order differential coefficient of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step;
A computer program for causing a computer to execute an internal temperature calculation step of calculating an internal temperature using a high-order differential coefficient calculated in the differential coefficient calculation step. An outer wall temperature measurement process for measuring the outer wall temperature of the material to be measured;
A heat transfer characteristic value calculating step of calculating a heat transfer characteristic value obtained by dividing the outer wall heat flux of the material to be measured by the heat conductivity of the material;
A noise removal step of removing noise components in the outer wall temperature measurement value measured in the outer wall temperature measurement step and the heat transfer characteristic value calculated in the heat transfer property value calculation step using a noise removal algorithm using a Legendre polynomial. When,
A differential coefficient calculating step of calculating a high-order differential coefficient of the outer wall temperature measurement value and the heat transfer characteristic value from which noise has been removed in the noise removing step;
An internal temperature calculation step of calculating an internal temperature using a higher-order derivative calculated in the derivative calculation step;
A computer program for causing a computer to execute a heat flux calculation step for obtaining a heat flux using an equation for calculating an internal temperature in the internal temperature calculation step.

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