Method and device for detecting heat transfer capacity by using temperature measuring element

Abstract

The invention discloses a method and a device for detecting heat transfer capacity by using a temperature measuring element, and belongs to the technical field of low-temperature heat transfer test.The method comprises the following steps: detecting steady-state temperature distribution in a to-be-detected state by using the temperature measuring element for a to-be-detected object; a cold source and a controllable heating element are utilized to act on the two ends of an object to be detected respectively, so that the steady-state temperature distribution of the object to be detected is consistent with the steady-state temperature distribution in a to-be-detected state, and the input power of the controllable heating element at the moment is read, namely the steady-state heat transfer amount of the object to be detected in the to-be-detected state. The use of dangerous media such as liquid hydrogen or liquid oxygen can be avoided, and the safety risk of low-temperature testing is solved; the heat transfer amount is directly obtained through an isothermal compensation mechanism, and the error of a heat transfer amount result fitted through temperature difference is eliminated; and multi-temperature-zone test can be realized, and full-temperature-zone measurement at low temperature is supported. The device can be widely applied to accurate testing of thermal performance of low-temperature systems in the fields of superconduction, spaceflight and the like.

Description

Technical Field

[0001] This invention relates to the field of low-temperature heat transfer testing technology, specifically to a method and device for accurately measuring minute heat transfer in low-temperature environments based on the steady-state temperature compensation principle. Background Technology

[0002] Accurate evaluation of heat transfer performance in cryogenic systems (such as liquid hydrogen / liquid helium storage tanks and superconducting magnets) is a core challenge for energy security and cutting-edge technology. Detection of heat leakage from insulation materials and tank support structures are critical processes that directly impact the storage efficiency and safety of cryogenic media. Current mainstream steady-state calorimetry techniques face several challenges in accurately measuring the minute heat transfer in such complex structures. Traditional evaporative calorimetry (e.g., Chinese patent document CN 102809581B) infers heat flow from the evaporation rate of the cryogenic liquid, but it can only be widely applied to tests near the boiling point of cryogenic liquids where there are no safety concerns, such as in the liquid nitrogen temperature range (77 K) and the liquid helium temperature range (4.2 K). Because evaporation calorimetry requires direct testing with liquid hydrogen in the liquid hydrogen temperature range, and the explosive nature of liquid hydrogen could trigger a chain reaction of safety accidents, this method cannot cover the liquid hydrogen temperature range. Furthermore, the sensible heat of liquid hydrogen and liquid helium is much greater than their latent heat of vaporization. During the process of the gas reaching the flow meter after the cryogenic liquid evaporates, it is easily affected by ambient heat, which greatly increases measurement uncertainty. Therefore, evaporation calorimetry cannot accurately measure minute changes in heat in extremely low temperature ranges. Based on this, Chinese patent document CN 108614007A proposes a performance testing device for multilayer insulation materials and composite insulation materials, using a refrigerator instead of cryogenic liquid to lower the temperature, avoiding the safety hazards of liquid hydrogen. The principle of this patented method is based on the fact that, under steady-state conditions, the heat transfer of a heat-conducting rod is equal to the heat flux through the insulation material being tested, and the thermal conductivity of the insulation material is inferred from this. However, this scheme does not clearly explain how to accurately measure the minute heat transfer on the heat-conducting rod; its embodiments only suggest calculating the heat transfer of the heat-conducting rod through temperature difference, without involving more specific measurement techniques. The key point is that in the deep cryogenic range, the thermal conductivity of metallic materials (such as copper) and some non-metallic materials (such as G10) exhibits a strong nonlinear temperature dependence, with variations reaching two to three orders of magnitude. According to Fourier's law... If only temperature difference With heat flux The mapping relationship between them is used to calculate or calibrate heat flux, while ignoring thermal conductivity. Significant, nonlinear variations within this temperature range will introduce considerable systematic errors. Therefore, schemes based on this principle are difficult to apply to the accurate measurement of minute heat loss (i.e., minute heat transfer) in cryogenic environments.

[0003] It should be noted that even without considering the low temperature issue, the patented method only mentions using the temperature difference to calculate the heat flux at that temperature difference, without using interpolation or integration along the temperature distribution of the heat-conducting rod to obtain more accurate thermal conductivity information. Therefore, it is impossible to accurately measure such minute heat changes.

[0004] Furthermore, in conventional practices for steady-state thermal conductivity measurements, the thermal conductivity value corresponding to the average temperature over the measured temperature range is often used for calculation. However, for materials with significantly nonlinear thermal conductivity, or samples with complex shapes and large lengths, using a single thermal conductivity value at the average temperature cannot accurately characterize the actual heat transfer behavior of the material under a specific temperature distribution. Therefore, even if both the temperature difference and the thermal conductivity (at the average temperature) are considered to characterize material properties, this method still has limitations and cannot guarantee accurate and reliable results in all practical application scenarios (especially in cryogenic environments requiring high-precision microcalorimetry).

[0005] In the field of cryogenic thermal energy metering, key scenarios such as the thermal stability assessment of liquid hydrogen storage tank support structures, performance verification of high-efficiency cryogenic insulation materials, and analysis of vacuum radiation heat transfer characteristics place stringent demands on the measurement accuracy and environmental interference resistance of heat flow detection systems. Existing technologies have the following significant limitations: First, while cryogenic liquid evaporation calorimetry can achieve indirect heat flow estimation, it involves safety risks related to the storage of volatile media, and measurement failures occur below liquid nitrogen temperatures due to the low latent heat of phase change in the medium. Second, while the thermal conductivity-temperature difference coupling method based on steady-state Fourier's law avoids the use of fluid working fluids, the thermal conductivity of materials exhibits a significant nonlinear temperature dependence under deep cryogenic conditions, and even with the introduction of an average thermal conductivity compensation mechanism, its errors remain inapplicable in various situations. Third, the coupling effect of thermal radiation and solid thermal conductivity in composite heat transfer scenarios leads to systematic deviations in traditional single-point temperature difference measurements. Summary of the Invention

[0006] This invention relates to the field of low-temperature heat transfer testing technology, aiming to solve the deflagration risk and failure problems of the existing evaporation calorimetry method due to the use of flammable media such as liquid hydrogen / liquid oxygen, as well as the system error defects caused by the strong nonlinear variation of the thermal conductivity of materials in the deep low-temperature region (e.g., the thermal conductivity of copper can fluctuate by two orders of magnitude at 20K). To this end, a direct measurement method of heat transfer based on the reproduction of steady-state temperature distribution is proposed. After recording the steady-state temperature distribution under the target heat flux through a distributed temperature measuring array, the compensation power is precisely adjusted by a controllable heating element until the same temperature distribution is reproduced. At this time, the compensation power value is the actual heat transfer, thereby completely avoiding the dependence on thermal conductivity parameters and nonlinear errors.

[0007] A method for detecting heat transfer using a temperature sensing element includes: for an object to be tested, using a temperature sensing element to detect the steady-state temperature distribution under the test state; using a cold source and a controllable heating element to act on both ends of the object to be tested, so that the steady-state temperature distribution of the object to be tested is consistent with the steady-state temperature distribution under the test state; reading the input power of the controllable heating element at this time, which is the steady-state heat transfer of the object to be tested under the test state.

[0008] If the state to be tested is already in thermal equilibrium, the steady-state temperature distribution under that state can be directly detected. If the state to be tested needs to be constructed, the corresponding thermal equilibrium state needs to be constructed in advance, and then the steady-state temperature distribution under that state needs to be detected.

[0009] Specifically, a method for detecting heat transfer using a temperature sensing element includes: constructing a thermal equilibrium state corresponding to the state to be tested for the object to be tested; detecting the steady-state temperature distribution of the object to be tested under the thermal equilibrium state using a temperature sensing element; removing the object to be tested from the state to be tested; placing a cold source at one end of the object to be tested; and heating the object to be tested at the other end using a controllable heating element, so that its steady-state temperature distribution is the same as the steady-state temperature distribution corresponding to the state to be tested, and it is in a steady state; recording the stable heating power of the controllable heating element to maintain this steady state; and the steady-state heating power value is the steady-state heat transfer of the object to be tested under the state to be tested.

[0010] Preferably, the controllable heating element is a controllable electric heating element. For example, a common heating resistor driven by a controllable constant current source can be used.

[0011] Preferably, the cold source can be a refrigeration unit, a low-temperature cold source, a constant temperature room, a low-temperature environment, or an environment at a specific temperature (such as the external environment where a certain object is located).

[0012] The method of this invention can be used to detect the steady-state heat transfer of a material in a specific test state, such as the heat transfer of a particular material under its corresponding working environment. The method can also be used for online testing of a device or material. For online testing, the method needs to be pre-calibrated to establish the data relationship between steady-state temperature distribution and steady-state heat transfer, creating a database for online testing.

[0013] Preferably, the method described above is used in advance to detect the steady-state heat transfer under multiple states corresponding to the object under test, and to establish a correlation database between steady-state temperature distribution and steady-state heat transfer; the steady-state temperature distribution of the object under test is detected online, and the corresponding steady-state heat transfer is obtained based on the constructed correlation database. More preferably, the steady-state temperature distribution and steady-state heat transfer are detected in a vacuum environment and within a heat-resistant radiation shield to achieve the construction of the correlation database.

[0014] Preferably, when performing online testing, if the detected steady-state temperature distribution is the same as a certain steady-state temperature distribution in the calibration database, the corresponding steady-state heat transfer is directly output as the steady-state heat transfer of the current state (or the current moment); if the detected steady-state temperature distribution is different from the steady-state temperature distribution in the calibration database, the corresponding steady-state heat transfer is obtained by interpolation and the data is saved into the associated database.

[0015] Furthermore, a temperature sensing element array is used to detect steady-state temperature distribution data. Depending on the structure of the object to be detected, different array distributions can be used. For example, for a long strip-shaped object to be detected, an axial distribution array can be used. In addition, the temperature sensing element array layout used in the calibration process and the detection process is generally the same, which further improves the detection accuracy and precision.

[0016] Furthermore, when using interpolation to obtain the corresponding steady-state heat transfer, firstly, find two or more neighboring points in the associated database that are closest to the detected steady-state temperature distribution, and then apply interpolation based on these two or more points to calculate the final steady-state heat transfer.

[0017] A method for online detection of heat transfer using a temperature sensing element includes: online detection of the temperature distribution of the object to be detected using the temperature sensing element, and then comparing the temperature distribution with steady-state temperature distribution data in a data pair in an associated database to obtain the corresponding steady-state heat transfer. For specific methods of obtaining this information, please refer to the above-mentioned content.

[0018] The present invention provides a method for detecting heat transfer using a temperature sensing element, which includes the following core steps:

[0019] After the object under test establishes steady-state heat transfer under the action of initial heat flux, its temperature distribution characteristics, i.e., the initial steady-state temperature distribution, are first obtained through a distributed high-precision temperature measurement array. Then, the external heat source input is cut off, and a controllable electric heating element is used to replace the heat source. The heating power is adjusted until the global temperature field distribution of the object under test achieves spatial consistency with the initial steady-state temperature distribution. Finally, the steady-state electric power value required to maintain this equivalent temperature field is directly defined as the equivalent steady-state heat flux of the object under test, thereby constructing a direct heat metering mechanism based on temperature distribution reproduction.

[0020] A device for detecting (or calibrating) heat transfer using a temperature sensing element, comprising:

[0021] A distributed temperature sensing element array containing at least two temperature sensing elements is used to obtain the steady-state temperature distribution of the object under test;

[0022] A cold source and a controllable heating element are applied to both ends of the object to be tested to form a target steady-state temperature distribution. The cold source can be replaced by the environment in which the object to be tested is located.

[0023] Furthermore, it also includes a data storage and processing unit for storing a correlation database of the detected steady-state temperature distribution and steady-state heat transfer, and obtaining the steady-state heat transfer corresponding to the input steady-state temperature distribution based on the correlation database.

[0024] Furthermore, it also includes a vacuum chamber, in which the object to be tested, the distributed temperature sensing element array, the cold source, and the controllable heating element are all disposed.

[0025] Furthermore, it also includes a heat radiation shield, in which the object to be detected, the distributed temperature measuring element array, and the controllable heating element are all housed.

[0026] Preferably, the system includes both a vacuum chamber and a heat-resistant radiation shield, with the heat-resistant radiation shield disposed within the vacuum chamber. This technical solution enables the detection of minute amounts of heat transfer.

[0027] Furthermore, a device for detecting heat transfer using a temperature sensing element, the device comprising:

[0028] An array of temperature sensing elements arranged along the object to be tested serves as the core sensing unit, used to obtain the steady-state temperature distribution of the object to be tested.

[0029] A controllable heating element that heats one end of the object to be tested;

[0030] A cold source used to cool the other end of the object being tested.

[0031] An optional multi-segment temperature-controlled radiant screen system, whose temperature distribution is matched with the material gradient to suppress environmental thermal interference;

[0032] As a preferred option, a low-temperature insulation structure can be integrated into the vacuum cavity to reduce environmental heat leakage errors.

[0033] As a preferred option, a thermal radiation screen can be added and a vacuum treatment can be implemented to eliminate heat loss caused by thermal radiation and thermal convection.

[0034] As a preferred option, the density of the temperature sensing element array can be adjusted to achieve distributed high-resolution detection of the temperature field;

[0035] As a preferred option, a low-temperature thermostat or a closed-loop refrigeration unit can be used as the cold source to avoid the risk of flammable and explosive media.

[0036] As a preferred approach, a heat transfer-temperature distribution mapping database can be established based on steady-state temperature control data to achieve interpolation prediction for untested operating conditions.

[0037] Preferably, the data storage and processing unit is also used to read and output the stable heating power of the controllable heating element; or, to read the steady-state temperature distribution data of the object to be tested online and compare the data with the constructed data to obtain the corresponding steady-state heat transfer.

[0038] Specifically, after the data storage and processing unit reads the online detection data, if the detected steady-state temperature distribution is the same as a certain steady-state temperature distribution in the associated database, it directly outputs the corresponding steady-state heat transfer as the steady-state heat transfer of the current state; if the detected steady-state temperature distribution is different from the steady-state temperature distribution in the associated database, it uses interpolation to obtain the corresponding steady-state heat transfer and saves the data into the associated database.

[0039] As a preferred embodiment, a device for calibrating / detecting heat transfer using a temperature sensing element includes:

[0040] Vacuum chamber, providing a vacuum environment;

[0041] A refrigeration unit, wherein the cold head of the refrigeration unit is disposed within the vacuum chamber to provide a cold source;

[0042] A temperature control system that controls the cooling temperature of the refrigeration unit's cold head;

[0043] A heat-shielding radiation shield installed inside a vacuum chamber;

[0044] A controllable heating element is installed inside the heat radiation shield;

[0045] During testing, the object to be tested is placed inside the heat radiation shield, with one end thermally connected to the cold head and the other end thermally connected to the controllable heating element.

[0046] As a specific application, it can be used to detect the heat transfer of thermal insulation materials. A device for detecting heat transfer using a temperature sensing element includes:

[0047] Vacuum chamber, providing a vacuum environment;

[0048] A refrigeration unit, wherein the cold head of the refrigeration unit is disposed within the vacuum chamber to provide a cold source;

[0049] The test chamber is used to locate the insulation material to be tested;

[0050] The object to be tested is connected between the test chamber and the cold head of the refrigerator;

[0051] Temperature measuring element installed on the object to be tested.

[0052] In the above technical solution, since the object to be tested is thermally connected to the test chamber, the heat passing through the insulation material under steady state is the same as the heat passing through the object to be tested. By detecting the temperature distribution of the object to be tested under steady state, the heat transfer through the object to be tested can be obtained, and thus the heat transfer of the insulation material to be tested can be obtained.

[0053] The data storage and processing unit can be a computer or an integrated chip with storage and processing functions.

[0054] The method of this invention can accurately measure minute heat changes, overcoming the limitations of existing technologies. The method establishes a steady-state temperature distribution by placing a cold source and a heat source at opposite ends of the object under test. Then, a controllable heating element is used to adjust the heating power to bring the material to an isothermal steady state. The stable heating power required to maintain this state is the steady-state heat transfer of the object under test. The corresponding device integrates a vacuum insulation structure, a temperature-controlled radiant screen, and a distributed temperature sensing element array, and is compatible with cold source modes such as refrigerators or cryostats.

[0055] To address the technical bottlenecks of existing technologies, this invention proposes a heat flow inversion method based on distributed temperature measurement. Its technological breakthroughs are reflected in three dimensions: 1) Accurate identification of heat flow paths is achieved by reconstructing the temperature field through a multi-node temperature measurement array; 2) A direct mapping relationship between temperature distribution and heat flux density is established using numerical heat transfer methods, eliminating explicit dependence on the thermal conductivity parameter of the medium; 3) Cross-interference between conduction and radiation is effectively isolated by adding reflective screens and insulating materials.

[0056] This invention eliminates the dependence on dangerous media such as liquid hydrogen / liquid oxygen and simultaneously solves the deflagration risk and phase change temperature range limitations of traditional evaporative calorimetry. Based on the first law of thermodynamics, it establishes a measurement of corresponding heat flow with the same temperature distribution. By compensating for the energy conservation of power and target heat flow, it bypasses the integral calculation of thermal conductivity in the traditional Fourier law and eliminates the systematic error caused by ignoring the nonlinear temperature change characteristics of thermal conductivity in the deep cryogenic region. This invention can meet the metering requirements of minute heat in cryogenic systems. Attached Figure Description

[0057] Figure 1 This is a simplified diagram of the testing device of the present invention.

[0058] Figure 2 This is a simplified diagram of the testing device in this invention used for detecting heat leakage in the support of a liquid hydrogen storage tank.

[0059] Figure 3 This is a simplified diagram of the testing apparatus of the present invention calibrated in the liquid hydrogen temperature range.

[0060] Figure 4 This is a simplified diagram showing the temperature change of the object under different heating amounts.

[0061] Figure 5 These are the test results of the temperature distribution of the aluminum rod under different heating conditions.

[0062] Figure 6 This is a schematic diagram of the testing device used in the actual measurement stage of heat transfer of thermal insulation materials. Detailed Implementation

[0063] The present invention will be further described below with reference to preferred embodiments and accompanying drawings. The descriptions of the embodiments are exemplary and not intended to limit the invention. Based on the knowledge of those skilled in the art, modifications or variations can be made to the embodiments without departing from the concept of the present invention, and such modifications or variations should be considered to fall within the protection scope of the present invention.

[0064] like Figure 1 As shown, this embodiment of the invention provides a method for detecting heat transfer using a temperature sensing element, comprising the following steps:

[0065] At least two temperature sensing elements 2 are arranged at intervals on the object to be tested 1;

[0066] Based on the state to be detected, a thermal equilibrium state is established, and the first steady-state temperature distribution data detected by the temperature measuring element 2 is acquired and recorded.

[0067] A controllable heating element 3 is set at one end of the object to be tested 1, and a cold source 4 is set at the other end; the input power of the controllable heating element 3 and the cooling temperature of the cold source 4 are adjusted until the temperature measuring element 2 detects that the second steady-state temperature distribution at both ends of the object to be tested 1 is consistent with the first steady-state temperature distribution data.

[0068] Record the stable input power of the controllable heating element 3 while maintaining the second steady-state temperature distribution; wherein, the stable input power value is the steady-state heat transfer of the object under test 1 in the first steady state.

[0069] The object to be tested can be a specific material or a structure, component, part or device used in situations where temperature control is required.

[0070] Depending on the structure of the object being tested, the number and arrangement of temperature sensing elements can be varied to detect the steady-state temperature distribution data of the object. For strip-shaped or columnar objects, two or more temperature sensing elements can be arranged at both ends to obtain their corresponding steady-state temperature distribution data. For objects with a certain width, double or multiple rows of temperature sensing element arrays can be arranged; for irregularly shaped objects, the temperature sensing element array can be arranged according to their structural characteristics. The temperature sensing elements are generally temperature sensors.

[0071] For online testing, the temperature sensing element array used in the calibration process is generally the same as the temperature sensing element array used in actual operation.

[0072] The state to be detected can be the state of the object to be detected in a certain environment, or the state at a certain specific temperature.

[0073] When a controllable electric heating element is selected, the input power is its corresponding stable heating power. In this embodiment, the controllable electric heating element is a resistor with a constant voltage source and adjustable power. A Keithlity 2700 meter is used to read the voltage and current signals. Using the above method, it is possible to detect the heat transfer of a test object under specific conditions, and it can also be used for the pre-calibration of materials.

[0074] like Figure 2 As shown, this embodiment of the invention provides an application of a detection device that uses a temperature sensing element to detect heat transfer in the leakage test of a liquid hydrogen storage tank support. The liquid hydrogen storage tank includes an inner tank 205 for storing liquid hydrogen and an outer tank 206 located in the atmospheric environment. Due to the low boiling point of liquid hydrogen, efficient thermal insulation must be maintained between the inner and outer tanks to reduce evaporation loss. A vacuum cavity is provided between the inner and outer tanks and filled with insulating material (not shown separately in the figure), and they are mechanically fixed by multiple stainless steel support structures 201 (i.e., the aforementioned object to be tested). However, these support structures constitute a thermal bridge (i.e., a leakage path) for heat transfer from the outer tank to the inner tank. Accurate measurement of this heat leakage is crucial for evaluating the insulation performance of the inner tank and for the safety design of the storage tank.

[0075] In this embodiment, the inner tank serves as an equivalent cold source; the outer tank, located at room temperature, serves as an equivalent heat source; the four stainless steel support structures 201 connecting the inner and outer tanks constitute the object to be tested 1; each support structure 201 has a rhodium temperature sensor 202 (i.e., temperature sensing element 2) at both ends. Through pre-calibration (which can be done using...), Figure 1 or Figure 3(The device shown detects calibration data) It establishes a relational database by relating the steady-state temperature distribution of the support structure to its corresponding steady-state heat transfer. During actual operation, the corresponding heat transfer can be obtained based on the temperature distribution data (target temperature distribution data) measured by the rhodium temperature sensors at both ends of each support. The total heat leakage from the outer tank to the inner tank through all support structures is then accurately calculated and accumulated. During heat transfer acquisition, if a steady-state temperature distribution with the same characteristics as the target temperature distribution exists in the relational database, the steady-state heat transfer corresponding to that distribution is directly output as the heat transfer data corresponding to the target temperature distribution at that time. If no identical steady-state temperature distribution exists, at least one nearest neighbor point larger than the target temperature distribution and at least one nearest neighbor point smaller than the target temperature distribution are searched in the database. The heat transfer corresponding to the target temperature distribution is then obtained using interpolation based on these nearest neighbors.

[0076] like Figure 3 and Figure 6 As shown, this embodiment of the invention provides an application of a detection device that uses a temperature sensing element to detect heat transfer in testing the comprehensive heat transfer of insulation materials in the liquid hydrogen temperature range, which includes two stages: calibration and actual measurement.

[0077] The device structure during the calibration phase is as follows: Figure 3 As shown, the GM 418 refrigerator cold head 304 (as a cold source) is placed inside the vacuum chamber 309 to maintain the required low-temperature environment. The first end of the aluminum rod 301 to be calibrated is fixed to the refrigerator cold head and thermally connected to it. A controllable heating element 3 is installed at the second end of the aluminum rod 301. In this embodiment, a constant voltage source for the controllable electric heating element is selected, and the resistance of the adjustable power is used. A Keithlity 2700 meter is used to read the voltage and current signals. A heat radiation shield 308 is installed on the outside of the aluminum rod 301. The heat radiation shield is connected to the cold end of the refrigerator to coordinate its temperature with the temperature distribution of the aluminum rod 301, significantly reducing the interference of radiant heat flow on the test. By adjusting the input power of the controllable heating element 3, different steady-state temperature distributions can be established at the two ends of the aluminum rod 301.

[0078] Figure 4 This schematically illustrates the temperature change trend at both ends of the material as heating power increases. Without temperature control (i.e., without activating the temperature control system), both ends of the material will increase with increasing heating power, allowing only a few temperature distribution scenarios to be tested. Using the Lakeshore temperature controller 307 (temperature control system), the temperature at one end of the object under test can be fixed while the heating power is varied, thus systematically measuring steady-state heat transfer under various temperature distribution combinations. At least two temperature measurement points (e.g., ...) are arranged on the aluminum rod 301. Figure 3 (Illustration: Two Cernox temperature sensors 302) record the temperature distribution (T) corresponding to the heating power P under different steady-state conditions.c,rod ,T h,rod The corresponding relational dataset is used to construct a queryable or interpolated heat transfer-temperature distribution relationship model (or heat transfer-temperature distribution association database). Figure 5 The relationship between the temperature distribution at both ends of an aluminum rod and the heating power is shown. The aluminum rod has a diameter of 34 mm and a total length of 400 mm. The light gray connecting line in the figure indicates the cold end temperature T under the same heat transfer (heating power). c,rod With hot end temperature T h,rod The approximate linear distribution law (the specific calibration temperature range depends on the application, for example, the liquid hydrogen temperature range of 15 K to 20 K in this embodiment).

[0079] Actual measurement stage of heat transfer of insulation materials, such as Figure 6 As shown, Figure 3 The controllable heating element 3 is replaced with an independent test chamber 610. The insulation material 611 to be tested (composed of an aluminized film and fiberglass paper) is wrapped around the circumference of the test chamber. The test chamber is placed in... Figure 3 In the vacuum chamber (310), the internal temperature is maintained at a set temperature of 20 K by the cold head of the refrigerator through the aluminum rod 301. Since the environment (vacuum chamber wall) is at room temperature (approximately 300 K), heat Q is transferred from the environment to the low-temperature test chamber through the insulation material 611. The heat Q obtained by the test chamber needs to flow to the cold head of the refrigerator through the aluminum rod connected to it to maintain its low-temperature set point. Under thermal equilibrium, the heat transferred to the test chamber through the insulation material is the same as the heat transferred from the test chamber to the cold head through the aluminum rod; therefore, accurately measuring the steady-state heat transfer of the aluminum rod is equal to the total heat transfer through the insulation material.

[0080] After starting the test system and allowing it to reach thermal equilibrium, read the steady-state temperature distribution at both ends of the aluminum rod detected by the Cernox temperature sensor in this state: Cold end T c,rod = 17.8 K, hot junction T h,rod =19.0 K. Based on the measured temperature distribution data, query the database or model established during the calibration phase (corresponding to the embodiment). Figure 4 The diagram or corresponding data table shown represents the relational database between steady-state temperature distribution and steady-state heat transfer. If the temperature distribution combination already exists in the calibration data, the corresponding heat transfer value is directly obtained. If the temperature distribution combination is not directly calibrated (representing normal conditions), the corresponding steady-state heat transfer Q is obtained through interpolation using the calibration data (such as data from adjacent points before and after), thereby obtaining the comprehensive heat transfer through the insulation material.

[0081] Example measured data: Under the stated steady-state conditions (T) c,rod = 17.8 K, T h,rod=19.0 K), and the heat transfer of the aluminum rod was determined to be Q =0.16 W through interpolation calculation, that is, the total heat transfer through the multi-layer insulation material to be tested is 0.16 W.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible modifications here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for detecting a heat transfer amount using a temperature measuring element, characterized by, The method comprises the following steps: For the object to be detected, the steady state temperature distribution under the state to be detected is detected by using a temperature measuring element; a cold source and a controllable heating element are used to act on both ends of the object to be detected, so that the steady state temperature distribution of the object to be detected is consistent with the steady state temperature distribution under the state to be detected, and the input power of the controllable heating element at this time is read, which is the steady state heat transfer amount of the object to be detected under the state to be detected.

2. The method of claim 1, wherein the temperature measuring element is a thermistor. For online detection, the steady state heat transfer amount of the object to be detected under multiple states is detected by using the method of claim 1, and a correlation database of steady state temperature distribution and steady state heat transfer amount is established; the steady state temperature distribution of the object to be detected is detected online, and the corresponding steady state heat transfer amount is obtained according to the established correlation database.

3. The method of claim 2, wherein the temperature measuring element is a thermistor. When detecting online, if the detected steady state temperature distribution is the same as a certain steady state temperature distribution in the correlation database, the corresponding steady state heat transfer amount is directly output; if the detected steady state temperature distribution is different from the steady state temperature distribution in the correlation database, the corresponding steady state heat transfer amount is obtained by using interpolation method, and the data is saved in the correlation database.

4. The method of claim 1, wherein the temperature measuring element is a thermistor. The steady state temperature distribution of the object to be detected is detected in a vacuum environment.

5. The method of claim 1, wherein the temperature measuring element is a thermistor. The steady state temperature distribution of the object to be detected is detected in a vacuum environment and a heat radiation environment.

6. A device for detecting heat transfer using a temperature sensing element, characterized in that, The method comprises the following steps: A distributed temperature measuring element array comprising at least two temperature measuring elements is used to obtain the steady state temperature distribution of the object to be detected; A cold source and a controllable heating element are used to act on both ends of the object to be detected to form a target steady state temperature distribution; during online detection, the cold source and the controllable heating element can be replaced by the environment where the two ends of the object to be detected are located.

7. The device for detecting a heat transfer amount using a temperature measuring element according to claim 6, wherein Further comprising a data storage processing unit for storing the correlation database of steady state temperature distribution and steady state heat transfer amount obtained by detection, and obtaining the corresponding steady state heat transfer amount of the input steady state temperature distribution according to the correlation database.

8. The device for detecting heat transfer amount using a temperature measuring element according to claim 6, wherein Further comprising a vacuum cavity, wherein the object to be detected, the distributed temperature measuring element array, the cold source and the controllable heating element are all arranged in the vacuum cavity.

9. The device for detecting heat transfer amount using a temperature measuring element according to claim 6, wherein Further comprising a heat radiation shielding screen, wherein the object to be detected, the distributed temperature measuring element array and the controllable heating element are all arranged in the heat radiation shielding screen.

10. The device for detecting heat transfer amount using a temperature measuring element according to claim 6, wherein The controllable heating element is a controllable electric heating element; the cold source is a low temperature liquid, a low temperature thermostat or a cold head of a refrigerator.

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