Heat load evaluation method and heat load evaluation apparatus

Abstract

To provide a heat load evaluation method and a heat load evaluation apparatus that are capable of evaluating heat load on a surface of an object varying with time.SOLUTION: A heat load evaluation method according to an embodiment includes first to fourth steps. In the first step, an estimated value of the heat load from a first time point to a second time point later than the first time point is set. In the second step, a first temperature at the second time point at a position spaced a predetermined distance from the object surface is calculated based on the estimated value. In the third step, a second temperature at the second time point at the position measured by a temperature measuring element disposed at the position is acquired. In the fourth step, the estimated value at a third time point between the first and second time points is corrected based on a difference between the first temperature and the second temperature.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a thermal load evaluation method and a thermal load evaluation device. [Background technology]

[0002] The thermal load on an object surface can be measured based on the temperature of the object surface.

[0003] However, as described above, under conditions where the surface of an object is exposed to high heat, if a temperature measurement element (e.g., a thermocouple) for measuring the temperature of the surface of the object is placed on the surface of the object for a long period of time, the temperature measurement element may fail. While it is possible to measure the temperature at a distance from the surface of the object using an infrared camera or the like, if the structure surrounding the object makes it impossible to place the infrared camera in a position where it can observe the surface of the object, the infrared camera may not be able to directly measure the surface temperature. Therefore, there is a need for a method that can evaluate the thermal load on a surface of an object, which changes over time, without measuring the surface temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-227366 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a thermal load evaluation method and a thermal load evaluation device for evaluating the thermal load on the surface of an object that changes over time. [Means for solving the problem]

[0006] According to an embodiment, a thermal load evaluation method for evaluating a thermal load on an object surface that changes over time is provided. The thermal load evaluation method includes first to fourth steps. The first step sets an estimated value of the thermal load from a first time point to a second time point that is later than the first time point. The second step calculates a first temperature at a position a predetermined distance from the object surface at the second time point based on the estimated value. The third step acquires a second temperature at the position at the second time point measured by a temperature measuring element disposed at the position. The fourth step corrects the estimated value at a third time point between the first time point and the second time point based on a difference between the first temperature and the second temperature. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 10 is a diagram for explaining a comparative example of the present embodiment. [Figure 2] FIG. 10 is a diagram for explaining the calculation principle of a comparative example of the present embodiment. [Figure 3] FIG. 10 is a diagram for explaining the results of simulating a heat load in a comparative example of the present embodiment. [Figure 4] FIG. 10 is a diagram for explaining the results of simulating a heat load in a comparative example of the present embodiment. [Figure 5] FIG. 1 is a diagram for explaining an embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing the functional configuration of a heat load evaluation device according to an embodiment of the present invention. [Figure 7] FIG. 1 is a diagram showing the hardware configuration of a heat load evaluation device according to an embodiment of the present invention. [Figure 8] 3 is a flowchart showing a processing flow by the thermal load evaluation device according to the present embodiment. [Figure 9] 5A and 5B are diagrams showing a specific example of the heat load evaluation process according to the embodiment. [Figure 10] 10A and 10B are diagrams showing simulation results of changes in heat load over time in the present embodiment and a comparative example of the present embodiment. [Figure 11] 10A and 10B are diagrams showing simulation results of changes in heat load over time in the present embodiment and a comparative example of the present embodiment. [Figure 12A] 4A and 4B are diagrams for explaining the accuracy of a thermal load evaluated using the thermal load evaluation device according to the present embodiment. [Figure 12B] 4A and 4B are diagrams for explaining the accuracy of a thermal load evaluated using the thermal load evaluation device according to the present embodiment. [Figure 13A] 4A and 4B are diagrams for explaining the accuracy of a thermal load evaluated using the thermal load evaluation device according to the present embodiment. [Figure 13B] 4A and 4B are diagrams for explaining the accuracy of a thermal load evaluated using the thermal load evaluation device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that a person skilled in the art can easily make are naturally included in the scope of the disclosure. For clearer explanation, the size, shape, etc. of each part may be changed from the actual embodiment and shown schematically in the drawings. Corresponding elements in multiple drawings may be given the same reference numerals, and detailed descriptions may be omitted.

[0009] In this embodiment, an evaluation device used to evaluate the thermal load on an object surface that changes over time (i.e., the time change of the thermal load on the object surface) will be described. Specifically, for example, a case is assumed in which a neutral particle beam is continuously irradiated onto a plasma in order to maintain the generation of the plasma. The neutral particle beam power transmitted through the continuously irradiated plasma corresponds to the thermal load evaluated in this embodiment.

[0010] First, a comparative example of this embodiment will be described with reference to Fig. 1. In this comparative example of this embodiment, as shown in Fig. 1, a disk-shaped beam limiter 1 is placed near the plasma, configured so that the neutral particle beam that has passed through the plasma is incident only on its surface, as indicated by the arrow. A circular through-hole is formed in the center of this beam limiter 1, extending in the direction in which the neutral particle beam flows (i.e., in the direction in which heat is transmitted).

[0011] Furthermore, in a comparative example of this embodiment, a measurement chip 2 is placed in a through hole formed in the beam limiter 1. The measurement chip 2 is embedded in the through hole so that the surface of the measurement chip 2 is flush with the surface of the beam limiter 1. This measurement chip 2 has a cylindrical body made of a metal with high thermal conductivity, such as copper, and two temperature measurement elements 3 and 4 arranged axially spaced apart from each other within this cylinder.

[0012] Here, if we consider that the surface 2a of the measurement chip 2 (hereinafter referred to as the heat-receiving surface) is the surface to which a thermal load corresponding to the neutral particle beam power is applied, the temperature measurement element 3 is installed, for example, at a position 1 mm from the heat-receiving surface 2a (hereinafter referred to as position A). The temperature measurement element 4 is installed, for example, at a position 3 mm from the heat-receiving surface 2a (hereinafter referred to as position B). The temperature measurement elements 3 and 4 measure temperature changes (temperatures that change over time) at positions A and B caused by the thermal load applied to the heat-receiving surface 2a. In other words, the two temperature measurement elements 3 and 4 are capable of measuring temperatures at two points in the direction in which the neutral particle beam flows.

[0013] These temperature measuring elements 3 and 4 may be, for example, Type-T (copper-constantan) thermocouples, but any element may be used as long as it can continuously measure temperature changes at a predetermined position and continuously output the measurement signal.

[0014] The temperature changes measured by these temperature measurement elements 3 and 4 are output to a heat load calculation circuit (e.g., a combination of an ADC, a personal computer, and dedicated software) which corresponds to a calculation device that calculates the time change in heat load on the heat receiving surface 2a of the measurement chip 2 based on the principle described below.

[0015] Next, the calculation principle of the heat load in a comparative example of this embodiment will be described with reference to Fig. 2. Heat received from the heat-receiving surface 2a of the measurement chip 2 is transferred to position A and position B in sequence.

[0016] In Figure 2, the distance x a , x b and distance x roi and the heat load q in and q out The distance x is shown. a is the distance between position A and the heat receiving surface 2a, and the distance x b is the distance between position B and the heat receiving surface 2a. roi is the distance between the heat receiving surface 2a and a predetermined position 2c between positions A and B. Furthermore, the heat load q in is the heat load on the heat receiving surface 2a, and the heat load q out is the heat load at a given location 2c.

[0017] The heat flow q per unit time regarding heat transfer is expressed by the following equations (1) and (2).

number

[0018] Here, κ in the above equations (1) and (2) is the thermal conductivity of the object (here, the material forming the measurement chip 2), C p is the constant pressure heat capacity of the object, ρ m is the density of the object, x is the position (here, the distance from the heat-receiving surface 2a), t is the time (time), and T is the temperature inside the object. Thus, the heat load q on the heat-receiving surface 2a of the measurement chip 2 is in can be expressed by the following equation (3).

number

[0019] By appropriately selecting positions A and B, the first term on the right side of equation (3) can be approximated by the following equation (4): Furthermore, the second term on the right side of equation (3) can be approximated by the following equation (5):

number

[0020] where T a (t) is the measured temperature at time t at position A, T b (t) indicates the measured temperature at time t at position B. That is, the heat load q at time t on the heat receiving surface 2a in can be expressed as the following equation (6).

number

[0021] The temperatures measured by the temperature measuring elements 3 and 4 are expressed as T a (t) and T b By substituting (t) in real time, the heat load received by the heat-receiving surface 2a can be continuously measured.

[0022] Here, the results of simulating the heat load in a comparative example of this embodiment will be described. Fig. 3 is a graph showing the relationship between the heat load (vertical axis) applied to the heat-receiving surface 2a and time (horizontal axis) in this simulation (i.e., the change in the heat load applied to the heat-receiving surface 2a over time in this simulation). In this simulation, it is assumed that the heat load starts to be applied to the heat-receiving surface 2a one second after the start of measurement and stops three seconds later.

[0023] Fig. 4 shows the heat load in a comparative example of this embodiment when the heat load shown in Fig. 3 is applied to the heat receiving surface 2a. The dashed line shows the result of substituting the temperatures measured at positions A and B into the first term on the right side of equation (6) in real time. The dashed line shows the result of substituting the temperatures measured at positions A and B into the second term on the right side of equation (6) in real time. By adding up the first and second terms of equation (6), the result shown by the solid line can be obtained as the heat load on the heat receiving surface 2a.

[0024] When comparing the heat load actually applied to the heat-receiving surface 2a (FIG. 3) with the heat load in the comparative example (FIG. 4), a discrepancy in value (so-called overshoot and undershoot) occurs near the start of the heat load application (after 1 second) and near the end of the heat load (after 3 seconds). One of the objectives of this embodiment is to suppress this discrepancy in value.

[0025] Next, this embodiment will be described. In this embodiment, a beam limiter 1 as shown in Fig. 5 is placed near the plasma. A measurement chip 5 is embedded in the through hole of the beam limiter 1.

[0026] The measurement chip 5 according to this embodiment has one temperature measurement element 6. The temperature measurement element 6 is located at a distance x c The temperature measuring element 6 is installed at a position away from the heat receiving surface 5a and measures the temperature change caused by the thermal load on the heat receiving surface 5a at the installation position. The temperature measuring element 6 outputs the measured temperature change to the thermal load evaluation device.

[0027] Fig. 6 is a diagram showing the functional configuration of the thermal load evaluation device 20. The thermal load evaluation device 20 has a setting unit 21, a calculation unit 22, an acquisition unit 23, a correction unit 24, a display unit 25, and a storage unit 26. The processing of each unit will be described in detail later with reference to the flowchart in Fig. 7, but will be briefly described here.

[0028] The setting unit 21 sets an initial guess. The initial guess is an estimated value of the change over time in the heat load applied to the heat receiving surface 5a. The initial value of the initial guess is set to an arbitrary value (for example, 0). Furthermore, the setting unit 21 performs a process of resetting the initial guess based on the value corrected by the correction unit 24.

[0029] The calculation unit 22 solves a heat transport equation (also called a heat conduction equation) using an initial guess to calculate the distance x c Hereinafter, the temperature calculated by the calculation unit 22 will be referred to as the "estimated temperature."

[0030] The acquisition unit 23 acquires the temperature from the temperature measurement element 6 at a distance x from the heat receiving surface 5a. c Hereinafter, the temperature acquired by the acquisition unit 23 will be referred to as the "measured temperature."

[0031] The correction unit 24 corrects the value of the initial guess at a predetermined time point based on the difference between the estimated temperature and the measured temperature.

[0032] The display unit 25 displays the initial guess stored in the memory unit 26 as a time change in the heat load on the heat receiving surface 5a, for example, on a display 34 (see FIG. 7). The time change in the heat load is displayed, for example, as a graph (see FIG. 10) with the horizontal axis representing time and the vertical axis representing the heat load.

[0033] The storage unit 26 stores various information used to evaluate the thermal load. The various information includes constants used in the equations (7) to (11) described below and initial guesses corrected by the correction unit 24.

[0034] 7 is a diagram showing the hardware configuration of the thermal load evaluation device 20. The thermal load evaluation device 20 is an information processing device (electronic device) realized by, for example, a personal computer (PC) or the like, and includes a CPU 31, a RAM 32, a nonvolatile memory 33, a display 34, and the like.

[0035] The CPU 31 is a processor for controlling the operation of various components within the thermal load evaluation device 20. The CPU 31 may be a single processor or may be configured with multiple processors. The CPU 31 executes various programs loaded from the non-volatile memory 33 to the RAM 32. These programs include an operating system (OS) and various application programs.

[0036] The nonvolatile memory 33 is a storage medium used as an auxiliary storage device. The RAM 32 is a storage medium used as a main storage device. Although only the nonvolatile memory 33 and the RAM 32 are shown in Fig. 7, the thermal load evaluation device 20 may also include other storage devices such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive).

[0037] 6 may be realized by causing the CPU 31 to execute a predetermined program, i.e., by software, or by dedicated hardware, or by a combination of software and hardware. The storage unit 26 is realized by, for example, a nonvolatile memory 33 or another storage device.

[0038] Furthermore, some or all of the functional components and hardware components of the heat load evaluation device 20 may be incorporated into the measurement chip 5.

[0039] Next, the flow of processing by the thermal load evaluation device 20 will be described. Fig. 8 is a flowchart showing the flow of processing by the thermal load evaluation device 20. In the following description, the start point of processing (start point of repetition) is referred to as time t i It is written as follows.

[0040] The setting unit 21 sets the time from the first time point to the time point t i An initial guess for the heat load up to time t is set (step S10).i From time t i From a given time t delay It is a time point before the first time point to the present time t i The initial guesses up to are set to a predetermined value (for example, 0).

[0041] The calculation unit 22 solves the heat transport equation based on the initial guess to calculate the distance x c Time t at a distance i Specifically, the estimated temperature of the object (here, the material forming the measurement chip 5) is calculated based on the time change q guess (x,t) and the temperature change over time T guess The following equations (7) and (8) express the relationship between (x, t)

number

[0042] That is, the time change of the above heat load q guess (x,t) with initial guess (i.e., q guess (0, t)) is applied, the time change of the temperature inside the object is calculated so that the formulas (7) and (8) hold. When solving the heat transport equations shown in the formulas (7) and (8) (calculating the time change of the temperature inside the object), a finite difference method using a predetermined step time and step length is used, for example. In this embodiment, of the time change of the temperature inside the object calculated in this way, the temperature inside the object at a distance x from the heat receiving surface 5a is calculated. c Time t at a distance i The temperature is used as the estimated temperature.

[0043] In this embodiment, the relational expressions in a one-dimensional system are used, as shown in Equations (7) and (8). In order to save computational resources, a method capable of performing calculations in a one-dimensional system as described above is desirable, but similar calculations are also possible in two-dimensional or three-dimensional systems. Furthermore, when solving the heat transport equation, methods other than the above-mentioned finite difference method (for example, the finite element method) may be used.

[0044] On the other hand, the acquisition unit 23 detects the temperature at a distance x from the temperature measuring element 6 to the heat receiving surface 5a. c Time t at a distance i The measured temperature is acquired (step S12).

[0045] The time t actually given to the heat receiving surface 5a i Heat load and time t i If the initial guess is different from the estimated temperature calculated in step S11, a difference occurs between the estimated temperature calculated in step S11 and the measured temperature acquired in step S12. Correction unit 24 corrects the initial guess based on the difference between the estimated temperature and the measured temperature.

[0046] Specifically, the correction unit 24 calculates the time t i Estimated temperature and time t i The difference between the measured temperature and δT(t i ) is related to the correction term δq(t i ) is calculated by equation (10) using a proportionality coefficient α (step S13).

number

[0047] Here, Δt is the step time when calculating the heat transport equation (Equation (7) and Equation (8)) using the finite difference method, and Δx is the step length when calculating the heat transport equation using the finite difference method. The proportionality coefficient α is determined in advance depending on the material used in the measurement chip 5, etc. In addition, the above-mentioned correction term δq(t i) is an example, and is not limited to the above-mentioned formulas (9) and (10). For example, when calculating the time change of the temperature inside the object in step S11, if the heat transport equation is solved by a method other than the difference method (for example, the finite element method), a correction term δq(t i ) is used.

[0048] This correction term δq(t i ) is used to correct the value of the initial guess. Here, after a thermal load is applied to the heat-receiving surface 5a, the thermal load is moved from the heat-receiving surface 5a to a distance x c It is considered that there is a time lag (time delay) before the temperature at a position distant by t i From a given time t delay The previous time t i -t delay The initial guess value (heat load) at i ) is used for correction (step S14). delay is the heat load applied to the heat receiving surface 5a at a distance x c This is the time until the temperature at a position a few meters away is affected, and is set in advance depending on the substance (material) used in the measurement chip 5, etc.

[0049] The process of step S14 by the correction unit 24 starts at time t i From a given time t delay The value of the previous initial guess is q in guess1 (t i -t delay ), the corrected initial guess value is q in guess2 (t i -t delay ), it can be expressed as the following equation (11).

number

[0050] According to the above equation (11), the process of step S14 determines the time t i -tdelay Initial guess(q in guess1 (t i -t delay )) is the correction term δq(t i ) will increase by

[0051] The storage unit 26 stores the time t corrected from the first time point in step S14. i -t delay The initial guess (heat load) up to this point is stored (step S15).

[0052] The thermal load evaluation device 20 determines whether or not a termination condition is satisfied (step S16). i or time t i -t delay is the end point predetermined by the user, the correction process in step S14 has been performed a predetermined number of times, the difference between the estimated temperature and the measured temperature at the temperature measurement point calculated using equations (7) and (8) when calculating the correction term is within a predetermined temperature difference, or an end instruction is given by the user from an input unit not shown.

[0053] If the termination condition is not satisfied (NO in step S16), the setting unit 21 determines whether the time t i -t delay ~Time t i+1 An initial guess is set up to the time t (step S17). The initial guess set in step S17 may be any value as long as it is a value set based on the corrected heat load. i+1 means that at time t i A predetermined time Δt after (i.e., t i+1 =t i +Δt).

[0054] Then, at time t i -t delay at the first time point, time t i+1 At time t i(step S18), and the process is repeated using the initial guess set in step S17 until the above termination condition is met.

[0055] If the termination condition is met in step S16 (YES in step S16), the display unit 25 displays the initial guess stored in the memory unit 26 on the display 34 as the heat load of the heat receiving surface 5a (time change in the heat load) that changes over time (step S19).

[0056] Next, the processing flow of the thermal load evaluation device 20 of this embodiment will be described using a specific example in Fig. 9. The dashed line in the upper diagram of Fig. 9 represents the initial guess (q in guess1 (t)) at time t i-1 is the starting time t of the iteration i A certain time Δt before (i.e., t i-1 =t i -Δt), which means the start time of the previous iteration.

[0057] The solid line in the lower diagram of FIG. 9 represents the distance x from the heat receiving surface 5a when the horizontal axis is time and the vertical axis is temperature. c 9 shows the measured temperature at a position away from the target object by 1000 kJ / s. The dashed line in the lower diagram of Fig. 9 shows the estimated temperature calculated by the calculation unit 22 using the heat transport equation when the horizontal axis represents time and the vertical axis represents temperature.

[0058] In the example of Figure 9, time t i In this case, the initial guess is set to the distance x from the heat receiving surface 5a based on the initial guess (step S100). c Next, the estimated temperature at a position at a distance x from the heat receiving surface 5a is calculated (step S101). c Then, the measured temperature at a position separated by t i Estimated temperature and time t i The difference between the measured temperature at time t i From a given time t delayThe value just before the time t is corrected (steps S104 to S105). i From a given time t delay The previous time t i -t delay is the time t i-1 -t delay (Time 1) and time t i Between.

[0059] By repeating steps S101 to S106, the time change of the heat load (q in guess2 (t)) can be evaluated.

[0060] Fig. 10 shows the simulation results of the change in thermal load over time in this embodiment and a comparative example of this embodiment when the same thermal load as in Fig. 3 is applied. The horizontal axis of Fig. 10 represents time, and the vertical axis represents the thermal load. The solid line represents the change in thermal load over time evaluated using this embodiment, and the dashed line represents the change in thermal load over time in the comparative example.

[0061] When comparing the thermal load evaluated using this embodiment with the thermal load in the comparative example, it can be seen that the thermal load evaluated using this embodiment has less deviation (overshoot and undershoot) from the actually applied thermal load (FIG. 3) than the comparative example.

[0062] Figure 11 shows the time t a The broken line indicates the time change of the actually applied heat load (i.e., the time change of the heat load shown in FIG. 3). The rise timing of the heat load evaluated by this embodiment (the timing when the value of the heat load becomes high) is later than the actually applied heat load by time t delay On the other hand, the rise time of the thermal load evaluated using this embodiment (the time from the rise timing until the time change of the thermal load and the time change of the actually applied thermal load become approximately the same) is about the same as that of the comparative example. In the example of FIG. 11, the time from the rise timing of the thermal load value until it has completely risen is about 2tdelay (2t delay =t delay ×2), and these 2t delay corresponds to the actual time resolution.

[0063] 12A, 12B, 13A, and 13B are diagrams for explaining the accuracy of the thermal load evaluated using the thermal load evaluation device 20. The horizontal axis of FIGS. 12A, 12B, 13A, and 13B represents time, and the vertical axis represents temperature. FIG. 12A shows the change in temperature over time measured by the temperature measuring element 6 when the thermal load shown in FIG. 3 is actually applied to the heat-receiving surface 5a. FIG. 12B shows the change in temperature over time calculated by solving the heat transport equation at the point of the temperature measuring element 6 when the thermal load evaluated using the thermal load evaluation device 20 when the thermal load shown in FIG. 3 is applied to the heat-receiving surface 5a (i.e., the thermal load shown by the solid line in FIG. 10) is actually applied to the heat-receiving surface 5a. As shown in FIGS. 12A and 12B, the changes in the two temperatures over time are roughly the same.

[0064] FIG. 13A shows the time t in the vicinity of 1 second in FIG. 12A. b 13B is an enlarged view of the time axis at a time t b 13A and 13B, the time-dependent changes in the two temperatures are roughly the same. In other words, it can be seen that there is not much difference between the heat load actually applied to the heat-receiving surface 5a and the heat load evaluated using the heat load evaluation device 20 (the time-dependent changes in the heat load on the heat-receiving surface 5a are accurately measured by the heat load evaluation device 20).

[0065] As described above, in this embodiment, the heat load evaluation device 20 is located at a distance x c The thermal load evaluation device 20 can evaluate (measure) a thermal load that reproduces the temperature change at a position (temperature measurement point) that is a distance away from the first time point of the thermal load by numerically solving the heat transport equation. i (second time point) is set, and based on the initial guess (estimated value), the distance x from the heat receiving surface 5a (object surface) is calculated.c Time t at a distance i The heat load evaluation device 20 calculates the estimated temperature (first temperature) at the distance x from the heat receiving surface 5a. c The time t measured by the temperature measuring element 6 located at a distance i Based on the difference between the measured temperature (second temperature) at the first time point and the i Time t between i -t delay The initial guess at (the third time point) is corrected. This corrected initial guess is used as the heat load (time change of the heat load) of the heat receiving surface 5a that changes with the passage of time.

[0066] By using this method, the overshoot and undershoot observed in the comparative example are alleviated, and more reliable results can be obtained.

[0067] Furthermore, in the comparative example, it was necessary to measure temperature changes at two positions (positions A and B) within the object. According to this embodiment, it is only necessary to measure temperature changes at one position within the object, which reduces the installation cost of the temperature measurement element. Also, the amount of data used for calculations can be reduced.

[0068] Furthermore, one or more temperature measurement elements may be placed within an object, and one of the temperature measurement elements may be used to evaluate the time change in the thermal load. In this case, the time change in the thermal load can be corrected using temperature changes measured by temperature measurement elements at other positions. For example, by correcting the difference between the time change in the thermal load measured using one temperature measurement element and the time change in the thermal load measured using another temperature measurement element to reduce the difference, the time change in the thermal load can be evaluated with greater accuracy.

[0069] Furthermore, according to this embodiment, it is possible to evaluate not only the heat load caused by the neutral particle beam but also the heat load that occurs in other situations, such as the heat load on the wall surface caused by the use of an accelerator or the energy generated by nuclear fusion, or the heat load on an object inside a high-temperature furnace used in the production of semiconductors or steel.

[0070] The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components within the scope of the gist of the invention in the implementation stage. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0071] 1...beam limiter, 2,5...measurement chip, 2a,5a...heat receiving surface, 2b...side surface, 3,4,6...temperature measurement element, 20...thermal load evaluation device, 21...setting unit, 22...calculation unit, 23...acquisition unit, 24...correction unit, 25...display unit, 26...storage unit, 31...CPU, 32...RAM, 33...non-volatile memory, 34...display

Claims

1. A heat load measurement method for evaluating a heat load on a surface of an object that changes over time, comprising: a first step of setting an estimated value of the heat load from a first time point to a second time point that is later than the first time point; a second step of calculating a first temperature at the second time point at a position a predetermined distance away from the surface of the object based on the estimated value; a third step of acquiring a second temperature at the location at the second time point measured by a temperature measuring element disposed at the location; a fourth step of correcting the estimated value of a third time point between the first time point and the second time point based on a difference between the first temperature and the second temperature; A thermal load evaluation method comprising:

2. The third time point is a time point that is earlier than the second time point by a time period during which a heat load applied to the object surface affects the temperature at the position. The thermal load evaluation method according to claim 1.

3. a fifth step of storing the estimated values ​​from the first time point to the third time point in a storage unit; repeating the processing of the first to fifth steps, with the third time point being the first time point and a fourth time point that is later than the second time point being the second time point; When the processes of the first to fifth steps are repeated, the estimated value from the first time point to the second time point is set based on the estimated value stored in the storage unit. The thermal load evaluation method according to claim 1.

4. The method further comprises a sixth step of displaying the estimated value stored in the storage unit as a time change of the thermal load. The thermal load evaluation method according to claim 3.

5. In the second step, the distance from the object surface is x, the time is t, the thermal conductivity of the object is κ, and the constant pressure heat capacity of the object is C ｐ , the density of the object is ρ ｍ When the thermal load is ｇｕｅｓｓ (x, t) and the time change T of the temperature of the object ｇｕｅｓｓ Represents the relationship between (x, t) [Equation 1] The first temperature is calculated based on the The thermal load evaluation method according to claim 1.

6. In the fourth step, the constant pressure heat capacity of the object is C ｐ , the density of the object is ρ ｍ , the step time is Δt, the step length is Δx, the proportionality coefficient is α, and the difference between the first temperature at the second time point and the second temperature at the second time point is δT(t ｉ ) and the correction term δq(t ｉ )of [Equation 2] Calculated using the formula: The correction term δq(t ｉ ) to correct the estimated value at the third time point. The thermal load evaluation method according to claim 1.

7. A thermal load evaluation device for evaluating a thermal load on a surface of an object that changes over time, comprising: a setting means for setting an estimated value of the heat load from a first time point to a second time point that is later than the first time point; a calculation means for calculating a first temperature at the second time point at a position a predetermined distance away from the surface of the object based on the estimated value; an acquisition means for acquiring a second temperature at the position at the second time point measured by a temperature measurement element disposed at the position; a correcting means for correcting the estimated value at a third time point between the first time point and the second time point based on a difference between the first temperature and the second temperature; A thermal load evaluation device comprising:

Images