Temperature fluctuation suppression device and method

Abstract

The invention provides a temperature fluctuation suppression device and method, and relates to the technical field of low-temperature and constant-temperature control. The device comprises a multi-layer closed cavity surrounding a refrigerating component of the refrigerating machine; the heating assembly comprises at least one heater, and each heater corresponds to one temperature control point in any layer of closed cavity and is used for heating the position where the temperature control point is located; the detection assembly comprises a temperature sensor corresponding to each heater and is used for detecting the temperature of the position where the corresponding heater is located; and the data processor is respectively connected with the heating assembly and the detection assembly, and is used for determining the optimal phase and the optimal amplitude when the temperature fluctuation of the corresponding temperature control point is minimum according to the temperature detected by each temperature sensor, and feeding back the optimal phase and the optimal amplitude to the heater at the corresponding temperature control point. According to the scheme, the heater ensures that the temperature in the closed cavity is stable in the optimal state, temperature fluctuation is restrained, and the low-temperature constant-temperature regulation and control effect is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of information management, and in particular to a device and method for suppressing temperature fluctuations. Background Art

[0002] The cryogenic temperature range (less than 120K) is crucial for the development of engineering applications in aerospace, high-energy physics, quantum science, and big data science. The temperature stability in this range directly impacts the performance of cryogenic constant-temperature systems. These systems typically utilize small, continuously operating refrigerators with low operating costs that require no cryogenic fluid. However, due to the refrigerator's operating principle and structure, the cyclical expansion of its working fluid (typically helium) during operation produces inherent temperature fluctuations. These fluctuations cannot meet the stable temperature requirements of high-precision experiments. Therefore, cryogenic constant-temperature systems using refrigerators as cooling sources must address these inherent temperature fluctuations.

[0003] Currently, the common method for suppressing the inherent fluctuations of a refrigerator is to optimize the system structure to achieve passive temperature attenuation. However, this method is difficult to achieve the desired temperature and temperature fluctuations. Another active temperature control method is to suppress the inherent temperature fluctuations of the refrigerator by adjusting the heating amount of the heater on the controlled element to achieve the desired temperature and temperature fluctuations. However, existing temperature suppression methods have the following problems: First, to achieve the desired temperature and temperature fluctuations, DC and AC currents are controlled separately. The two currents need to be controlled in a coordinated manner to achieve the target, which is cumbersome and prone to incoordination. Second, they only consider the phase angle matching of the temperature control current and the temperature fluctuation, without considering the matching of the temperature control current amplitude with the temperature fluctuation amplitude, making it difficult to achieve efficient temperature control results. Third, to determine the phase angle of the temperature control current, the phase must be divided into equal parts and matched one by one, which is complex and difficult to automate and maintain over the long term. Fourth, the temperature control point is limited to the refrigerator's cold source, and active temperature control of other temperature control points that are affected by the temperature fluctuation caused by the cooling transfer is not considered, thus failing to achieve multi-stage combined temperature control.

[0004] SUMMARY OF THE INVENTION

[0005] The present invention provides a temperature fluctuation suppression device and method to solve the problems of complex dual-current collaborative temperature control, incomplete temperature control current matching parameters, and difficult and non-automatic determination of the optimal temperature control current parameters in existing active temperature control. By adopting a single current to automatically control the optimal values ​​of the temperature control current phase and amplitude at multiple temperature control points, high-stability temperature control in a low-temperature constant temperature device is achieved.

[0006] According to a first aspect of the present invention, the present invention provides a temperature fluctuation suppression device, the device comprising: A multi-layer sealed cavity surrounding the refrigeration components of the refrigerator; A heating assembly, the heating assembly comprising at least one heater, each heater corresponding to a temperature control point in any layer of the closed cavity, for heating the location of the temperature control point; A detection component, the detection component including a temperature sensor corresponding to each heater, for detecting the temperature at a location where the corresponding heater is located; A data processor is connected to the heating component and the detection component respectively, and is used to determine the phase and amplitude when the temperature fluctuation of the corresponding temperature control point is minimized according to the temperature detected by each temperature sensor, obtain the optimal phase and optimal amplitude and feed them back to the heater at the corresponding temperature control point.

[0007] In some possible implementations, the multi-layer sealed cavity includes a first sealed cavity, a second sealed cavity, a third sealed cavity, and a fourth sealed cavity; The second sealed cavity is located inside the first sealed cavity, the third sealed cavity is located inside the second sealed cavity, and the fourth sealed cavity is located inside the third sealed cavity; The first sealed cavity surrounds the refrigerator head, the second sealed cavity surrounds the first-level cold head of the refrigerator, the third sealed cavity surrounds the second-level cold head of the refrigerator, and the fourth sealed cavity serves as an experimental chamber.

[0008] In some possible implementations, the first sealed cavity includes a first cylinder with an opening and a first-stage flange, the first-stage flange is connected to the head of the refrigerator, and the first-stage flange blocks the opening of the first cylinder; The second sealed cavity includes a second cylinder with an opening and a second-stage flange, the second-stage flange is connected to the first-stage cold head of the refrigerator, and the second-stage flange blocks the opening of the second cylinder; The third sealed cavity includes a third cylinder with an opening and a third-stage flange, wherein the third-stage flange is connected to the secondary cold head of the refrigerator, and the third-stage flange blocks the opening of the third cylinder; The fourth sealed cavity includes a fourth cylinder with an opening and a fourth-stage flange. The fourth-stage flange is connected to the third-stage flange via a connecting shaft, and the fourth-stage flange blocks the opening of the fourth cylinder.

[0009] In some possible implementations, the first cylinder is made of stainless steel or aluminum, and the second cylinder, the third cylinder, and the fourth cylinder are all made of copper or oxygen-free copper.

[0010] In some possible implementations, the heating assembly includes a first heater, a second heater, and a third heater; The first heater is fixed on the secondary cold head of the refrigerator, the second heater is fixed on the third-stage flange, and the third heater is fixed on the fourth-stage flange.

[0011] In some possible implementations, the detection component includes a first temperature sensor, a second temperature sensor, a third temperature sensor, and a fourth temperature sensor; The first temperature sensor corresponds to the first heater, the second temperature sensor corresponds to the second heater, and the third temperature sensor corresponds to the third heater. The first temperature sensor is fixed on the secondary cold head of the refrigerator, the second temperature sensor is fixed on the third flange, and the third temperature sensor is fixed on the fourth flange.

[0012] In some possible implementations, each heater in the heating assembly operates through the following steps: A fixed current output is selected according to the temperature setting value to heat the corresponding temperature control point until the temperature is stable; and a current is output according to the optimal phase and optimal amplitude feedback from the data processor to heat the temperature control point.

[0013] In some possible implementations, the data processor determines the optimal phase for each heater by the following steps: generating sinusoidal currents with different phase angles between 0 and 360° at fixed time intervals based on the fixed current, and applying each sinusoidal current to the heater at a fixed time; Performing temperature fluctuation analysis on temperature data detected by the corresponding temperature sensor when the heater outputs sinusoidal currents with different phase angles, and taking the phase angle corresponding to the minimum temperature fluctuation as the optimal phase; The data processor determines the optimal amplitude for each heater by: Determining a theoretical amplitude based on the optimal phase, determining an amplitude scanning range according to the theoretical amplitude, and causing the heater to apply each amplitude within the amplitude scanning range at fixed time intervals; A temperature fluctuation analysis is performed on the temperature data detected by the corresponding temperature sensor when the heater is applied with various amplitudes, and the amplitude corresponding to the minimum temperature fluctuation is used as the optimal amplitude.

[0014] In some possible implementations, the data processor re-determines the optimal phase and the optimal amplitude for each heater at preset time intervals.

[0015] According to a second aspect of the present invention, the present invention further provides a method for suppressing temperature fluctuations, the method comprising: adding the above-mentioned temperature fluctuation suppression device to a refrigerator.

[0016] The present invention provides a temperature fluctuation suppression device and method, which isolates the internal sealed cavity from the external environment by setting up a multi-layer sealed cavity to surround the refrigeration components of the refrigerator, and then uses a heating component including at least one heater to heat the temperature control point in the sealed cavity to balance the temperature fluctuation of the refrigerator. Then, the temperature of the temperature control point is detected by the temperature sensor corresponding to each heater, and then the temperature fluctuation analysis is performed on the data returned by the temperature sensor using a data processor, so as to find the optimal phase and optimal amplitude of the heater current that can minimize the temperature fluctuation of each temperature control point, so that the heater can ensure the stability of the temperature inside the sealed cavity in the optimal state, thereby suppressing the temperature fluctuation and significantly improving the low-temperature constant temperature control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of the temperature fluctuation suppression device provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the internal structure of the multi-layer closed cavity provided by the present invention.

[0020] Figure 3 These are the temperature control results of the temperature control current provided by the present invention at different phase angles.

[0021] Figure 4 These are the temperature control results of the temperature control current provided by the present invention at different amplitudes.

[0022] [Description of Reference Numerals]

[0023] 100: machine head; 110: refrigerator; 120: first-stage cold head; 130: second-stage cold head; 140: connecting shaft; 200: Multi-layer sealed cavity; 210: first sealed cavity; 211: first cylinder; 212: first stage flange; 220: second sealed cavity; 221: second cylinder; 222: second stage flange; 230: third sealed cavity; 231: third cylinder; 232: third stage flange; 220: fourth sealed cavity; 241: fourth cylinder; 242: fourth stage flange; 300: heating assembly; 310: first heater; 320: second heater; 330: third heater; 400: detection component; 410: first temperature sensor; 420: second temperature sensor; 430: third temperature sensor; 500: Data processor. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0025] The following combination Figures 1 to 4 A temperature fluctuation suppression device and a temperature fluctuation suppression method of the present invention are described.

[0026] Figure 1 This is a schematic diagram of the structure of the temperature fluctuation suppression device provided by the present invention. Please refer to Figure 1 As shown, this embodiment provides a temperature fluctuation suppression device, which includes four parts: a multi-layer sealed cavity 200, a heating component 300, a detection component 400 and a data processor 500. The following will be described in detail with reference to each component: A multi-layer sealed cavity 200 surrounds the refrigeration components of the refrigerator 110. The multi-layer sealed cavity 200 refers to a multi-layer structure formed by nesting cavities in sequence, from inside to outside. Each layer of the multi-layer sealed cavity 200 is a sealed cavity. It should be noted that the number of layers of the multi-layer sealed cavity 200 can be greater than or equal to two. In specific implementations, the multi-layer sealed cavity structure can adopt three to six layers, taking into account the installation process and the requirements for constant temperature accuracy.

[0027] It should be noted that Figure 1 Although the refrigerator 110 is shown in the figure, the refrigerator 110 does not belong to the temperature fluctuation suppression device. The refrigerator 110 is shown to facilitate understanding of the assembly state of the temperature fluctuation suppression device and the refrigerator.

[0028] The heating component 300 includes at least one heater, each heater corresponding to a temperature control point in any layer of the closed cavity, and is usually installed at the cold head of the refrigerator or on the flanges of each level to heat the location of the temperature control point, wherein the heater is fixed on the corresponding temperature control point.

[0029] In this embodiment, the temperature control point refers to the location in the closed cavity where the heater is required for temperature control. Any number of temperature control points can be set in a closed cavity. The number of temperature control points can be set according to the distance between each layer of the closed cavity and the innermost experimental chamber. For example, in the case of a closed cavity with five layers, where the innermost layer is the experimental chamber, multiple temperature control points can be set in the third and fourth layers respectively, and no temperature control point can be set for the outermost closed cavity. It should be noted that the number and location of the temperature control points in this embodiment are for illustration only and should not be understood as limiting the scheme of the present invention.

[0030] The detection component 400 includes a temperature sensor corresponding to each heater, and is used to detect the temperature at the location of the corresponding heater.

[0031] During the specific implementation process, the temperature sensor can be fixed on the component used to fix the heater, and the distance between the temperature sensor and the heater can be set according to the experimental conditions. The temperature sensor measures the temperature of the temperature control point by measuring the temperature of the fixed component. Multiple temperature sensors can also be set at a unified measurement point and the data results can be weighted averaged to ensure the uniformity and accuracy of the temperature data.

[0032] The data processor 500 is connected to the heating component 300 and the detection component 400 respectively, and is used to determine the phase and amplitude when the temperature fluctuation of the corresponding temperature control point is minimized according to the temperature detected by each temperature sensor, obtain the optimal phase and optimal amplitude and feed them back to the heater at the corresponding temperature control point.

[0033] The temperature fluctuation suppression device of this embodiment is configured by arranging a multi-layer sealed cavity to surround the refrigeration components of the refrigerator, so that the internal sealed cavity is isolated from the external environment, and then a heating component including at least one heater is used to heat the temperature control points in the sealed cavity to balance the temperature fluctuations of the refrigerator. The temperature of the temperature control points is then detected by temperature sensors corresponding to each heater, and the data processor is used to analyze the temperature fluctuations of the data returned by the temperature sensor, so as to find the optimal phase and optimal amplitude of the heater current that can minimize the temperature fluctuations of each temperature control point, so that the heater can ensure the stability of the temperature inside the sealed cavity in the optimal state, thereby suppressing the temperature fluctuations and significantly improving the low-temperature constant temperature control effect.

[0034] For some possible implementations, see Figure 2 As shown, the multi-layer sealed cavity 200 includes a first sealed cavity 210, a second sealed cavity 220, a third sealed cavity 230 and a fourth sealed cavity 240; The second sealed cavity 220 is located inside the first sealed cavity 210 , the third sealed cavity is located inside the second sealed cavity 220 , and the fourth sealed cavity 240 is located inside the third sealed cavity 230 ; It should be noted that the volumes of the first sealed cavity 210, the second sealed cavity 220, the third sealed cavity 230, and the fourth sealed cavity 240 decrease in order. In the specific implementation process, to ensure the temperature control effect, the sealed cavities in adjacent layers do not contact each other. The sealed cavities in each layer can adopt the same shape, such as all four layers of sealed cavities are rectangular or spherical.

[0035] The first sealed cavity 210 surrounds the head 100 of the refrigerator 110, the second sealed cavity 220 surrounds the primary cold head 120 of the refrigerator 110, the third sealed cavity 230 surrounds the secondary cold head 130 of the refrigerator 110, and the fourth sealed cavity 240 serves as an experimental chamber.

[0036] The temperature fluctuation suppression device of this embodiment has four layers of multi-layer sealed cavities. The three outer layers of sealed cavities surround the head of the refrigerator and the two-stage cold head in sequence, and the innermost fourth layer of sealed cavity is used as the experimental chamber. It can not only isolate the influence of the external environment on the temperature of the experimental chamber, but also adapt to the refrigeration components of the refrigerator, and weaken the influence of the external environment and the refrigerator on the temperature of the innermost experimental chamber.

[0037] For some possible implementations, please refer again to Figure 2 As shown, the first sealed cavity 210 includes a first cylinder 211 with an opening and a first-stage flange 212 , wherein the first-stage flange 212 is connected to the head 100 of the refrigerator 110 , and the first-stage flange 212 blocks the opening of the first cylinder 211 ; The second sealed cavity 220 includes a second cylinder 221 with an opening and a second flange 222 . The second flange 222 is connected to the first-stage cold head 120 of the refrigerator 110 , and the second flange 222 blocks the opening of the second cylinder 221 . The third sealed cavity 230 includes a third cylinder 231 with an opening and a third flange 232 . The third flange 232 is connected to the secondary cold head 130 of the refrigerator 110 , and the third flange 232 blocks the opening of the third cylinder 231 . The fourth sealed cavity 240 includes a fourth cylinder 241 with an opening and a fourth flange 242 . The fourth flange 242 is connected to the third flange 232 via a connecting shaft 140 , and the fourth flange 242 blocks the opening of the fourth cylinder 241 .

[0038] The temperature fluctuation suppression device of this embodiment has four sealed cavities constructed into a combination of a cylinder and a flange, so that the temperature fluctuation suppression device can be quickly and easily assembled with the refrigerator, and has good flexibility and versatility.

[0039] In some possible implementations, the first cylinder 211 is made of stainless steel or aluminum, and the second cylinder 221 , the third cylinder 231 , and the fourth cylinder 241 are all made of copper or oxygen-free copper.

[0040] For some possible implementations, please refer again to Figure 2 As shown, the heating assembly 300 includes a first heater 310 , a second heater 320 and a third heater 330 ; The first heater 310 is fixed to the secondary cold head 130 of the refrigerator 110 , the second heater 320 is fixed to the third-stage flange 232 , and the third heater 330 is fixed to the fourth-stage flange 242 .

[0041] The temperature fluctuation suppression device of this embodiment is designed for a four-layer closed cavity structure, and heaters are respectively arranged on the secondary cold head and the flanges at the sealing of the two internal cavity layers. That is, two temperature control points are selected in the second-layer closed cavity, and one temperature control point is selected in the third-layer closed cavity, thereby realizing the reasonable and effective setting of temperature control points.

[0042] For some possible implementations, please refer again to Figure 2 As shown, the detection component 400 includes a first temperature sensor 410, a second temperature sensor 420, a third temperature sensor 430 and a fourth temperature sensor; The first temperature sensor 410 corresponds to the first heater 310 , the second temperature sensor 420 corresponds to the second heater 320 , and the third temperature sensor 430 corresponds to the third heater 330 . The first temperature sensor 410 is fixed on the secondary cold head 130 of the refrigerator 110 , the second temperature sensor 420 is fixed on the third-stage flange 232 , and the third temperature sensor 430 is fixed on the fourth-stage flange 242 .

[0043] The temperature fluctuation suppression device of this embodiment sets temperature sensors for the three selected temperature control points respectively, so as to realize temperature measurement of the corresponding temperature control points, thereby realizing real-time monitoring of the impact of each heater on the temperature after operation, and providing reliable data support for subsequent regulation of the heater.

[0044] In some possible implementations, each heater in the heating assembly 300 operates through the following steps: Selecting a fixed current output according to the temperature setting value to heat the corresponding temperature control point until the temperature is stable; and

[0045] In this embodiment, the temperature stability value does not mean that the temperature is stable at a certain value. The temperature stability may mean that the deviation of the temperature relative to a certain value is continuously within a set range, that is, no large temperature deviation occurs.

[0046] The current is output according to the optimal phase and optimal amplitude fed back by the data processor 500 to heat the temperature control point.

[0047] In the temperature fluctuation suppression device of this embodiment, each heater is configured to first be heated to a relative temperature state with a fixed current, and then the optimal amplitude and optimal phase feedback from the data processor are applied to achieve accurate control of the working state of each heater.

[0048] In some possible implementations, the data processor 500 determines the optimal phase for each heater by the following steps: generating sinusoidal currents with different phase angles between 0 and 360° at fixed time intervals based on the fixed current, and applying each sinusoidal current to the heater at a fixed time; In a specific implementation, to ensure the data processor's efficiency in finding the optimal phase, the process can be set to start at zero degrees and use a fixed phase difference as a step size until the phase reaches 360 degrees. In a specific implementation, when a high temperature stabilization accuracy is required, the phase difference step size can be set relatively small, such as 15 degrees. When the required accuracy is not high, the phase difference step size can be set relatively large, such as 45 degrees, to ensure search efficiency. It should be noted that the fixed time interval should ensure that the current output has at least one complete cycle.

[0049] Performing temperature fluctuation analysis on temperature data detected by the corresponding temperature sensor when the heater outputs sinusoidal currents with different phase angles, and taking the phase angle corresponding to the minimum temperature fluctuation as the optimal phase; The data processor 500 determines the optimal amplitude for each heater by: Determining a theoretical amplitude based on the optimal phase, determining an amplitude scanning range according to the theoretical amplitude, and causing the heater to apply each amplitude within the amplitude scanning range at fixed time intervals; In the specific implementation process, the theoretical amplitude is a fixed amplitude, and the amplitude scanning range is an amplitude interval close to the theoretical amplitude. For example, if the theoretical amplitude is 1.1, the amplitude scanning range can be an interval consisting of all amplitudes that deviate from the theoretical amplitude by no more than 0.1, that is, [1.0, 1.2]. In order to ensure the efficiency of the data processor in finding the optimal amplitude, for each amplitude in the amplitude scanning range, it can be set to start from the minimum boundary, with a fixed amplitude difference as the step size, until the phase reaches the maximum boundary value of the amplitude. In the specific implementation process, when the required temperature stabilization accuracy is high, the amplitude difference can be set relatively small, such as with a step size of 0.01. When the required accuracy is not high, in order to ensure the search efficiency, the amplitude difference can be set relatively large, such as with a step size of 0.5. Similarly, the fixed time interval should satisfy that the current output has at least one complete cycle.

[0050] A temperature fluctuation analysis is performed on the temperature data detected by the corresponding temperature sensor when the heater is applied with various amplitudes, and the amplitude corresponding to the minimum temperature fluctuation is used as the optimal amplitude.

[0051] This embodiment of the temperature fluctuation suppression device further provides a method for using a data processor to find the optimal amplitude and phase. By traversing different phase intersections and amplitudes in a specific manner, the data processor analyzes temperature fluctuations to determine the optimal control state for each heater with high accuracy. The device also considers the influence of the temperature control current's phase angle and amplitude on temperature control, resolving the issue of incomplete temperature control current matching parameters and achieving more efficient temperature control results.

[0052] In some possible implementations, the data processor 500 re-determines the optimal phase and the optimal amplitude for each heater at preset time intervals.

[0053] In a specific implementation process, a timer or a counter may be used to implement detection of a preset time interval. For example, the preset time interval is 6 hours. Then, every 6 hours, the data processor re-determines the optimal phase and optimal amplitude for each heater.

[0054] The temperature fluctuation suppression device of this embodiment further improves the temperature fluctuation suppression effect and has better stability by causing the data processor to repeatedly search for the optimal phase and optimal amplitude for each heater at preset time intervals.

[0055] In another embodiment, in order to facilitate understanding of the solution of the present invention, the following will continue with Figure 2 Taking the temperature fluctuation suppression device with four sealed cavities shown in the figure as an example, the working process of using the temperature fluctuation device to achieve low temperature control will be described in detail below: First, based on the temperature set point, the heater outputs a fixed current to reach a temperature near the preset level.

[0056] Next, after the temperature stabilizes, the optimal phase angle of the temperature-control current is determined. Based on the existing fixed current, the heater generates a sinusoidal current with a phase angle ranging from 0° to 360° every half hour or less. After the current phase completes a full cycle, the phase angle corresponding to the minimum temperature fluctuation at the control point is the optimal phase. This optimal phase angle is fed back to the heater's power signal, ensuring that the power signal continuously outputs the determined optimal phase.

[0057] The optimal temperature-control current amplitude is then determined based on the optimal phase angle. The current amplitude sweep range is then determined based on the theoretically calculated amplitude. Each amplitude is scanned for one cycle. The amplitude corresponding to the minimum temperature fluctuation at the temperature-control point is the optimal active temperature-control current amplitude. This optimal amplitude is fed back to the heater's power signal, ensuring that the power signal continuously outputs the determined optimal amplitude.

[0058] Finally, the optimal phase and amplitude of the current are searched again every 6 hours or longer to ensure that the active temperature control current can respond in time when the amplitude and phase of the refrigerator temperature fluctuation change, thereby achieving highly stable temperature control of the system.

[0059] Taking the secondary cold head of a refrigerator as an example, the theoretical calculation method for the optimal phase and amplitude of the active temperature control current is explained. For the cold head of a refrigerator, its thermal balance can be expressed as follows: Formula 1; Where M is the mass of the refrigerator head, in kg; C is the heat capacity of the refrigerator material, in J / (kg·K); T aim is the target temperature of temperature control, in K; is the heating capacity of the heater, in W; is the cooling capacity of the refrigerator, in W; 、 、 They represent fluctuations in temperature, heat, and cooling respectively.

[0060] After reaching the target temperature and stabilizing, Formula 1 can be written as Formula 2 and Formula 3

[0061] Formula 2; Formula 3; Among them, the heating The size of is determined by the set temperature. The heat and temperature fluctuation values ​​can be expressed by a sine function, as shown in Equation 4: Formula 4; in, Indicates heating capacity The phase angle, Indicates the phase angle of the refrigerator cold head temperature.

[0062] Combining Formula 2 to Formula 4, we can get: Formula 5; Based on the relationship between the sine and cosine functions, the optimal phase and amplitude of the temperature control current can be calculated, as shown in Equation 6 below.

[0063] Formula 6; The theoretical optimal amplitude of the temperature-control current can be determined based on data such as the material mass and the original temperature fluctuation at the control point. The optimal phase of the temperature-control current is 270° different from the phase of the temperature fluctuation at the control point. However, in actual experiments, due to the presence of structural thermal resistance and contact thermal resistance, there is a delay in the system response. Furthermore, the response time varies from system to system, so the optimal phase angle of the temperature-control current still needs to be precisely determined through experimentation.

[0064] Continuing with the example of the heater on the secondary cold head 130 , let's assume that a computer is used as a data processor and the heater 310 on the secondary cold head 130 is used as an example. The optimal phase angle and the optimal amplitude are determined as follows: First, three temperature data sensors are used to collect the temperatures of the secondary cold head 130, the third flange 232, and the fourth flange 242, and transmit them to the computer through the electrical measuring equipment. According to the set expected temperature, the heater continuously outputs power. Increase / decrease the temperature to a preset temperature point; Furthermore, when the temperature reaches the preset temperature, the temperature of the secondary cold head 130, the third flange 232 and the fourth flange 242 are collected and analyzed on the computer side for the temperature fluctuation amplitude ΔT0, frequency f and phase angle φ0. The formula can be used To express; Furthermore, the heater 310 on the secondary cold head 130 has an existing heating capacity. On the basis of this, a sinusoidal current ΔQ with a phase angle from 0° to 360° is generated at intervals. heat , after completing a full cycle scan, the phase angle φ corresponding to the minimum temperature fluctuation at the temperature control point is the optimal phase; Furthermore, the optimal phase angle is fed back to the heater 310 on the secondary cold head 130 so that the power signal continuously outputs the determined optimal phase angle φ; Furthermore, based on the obtained parameters related to the temperature fluctuation at the temperature control point of the secondary cold head 130, the theoretical optimal amplitude of the temperature control current is preliminarily determined. Perform calculations; Furthermore, the current amplitude scanning range is determined based on the amplitude ΔQ0 obtained by theoretical calculation. Each amplitude is scanned for one cycle. The amplitude corresponding to the minimum temperature fluctuation at the temperature control point 5 of the secondary cold head 130 is the optimal amplitude of the active temperature control current. Furthermore, the optimal amplitude is fed back to the heater 310 on the secondary cold head 130 so that the power signal continuously outputs the determined optimal amplitude; Furthermore, the optimal phase and amplitude of the temperature control current on the third-stage flange 232 and the fourth-stage flange 242 are determined in sequence and fed back to the respective heaters 310 to continuously output the optimal phase and amplitude of the current; Furthermore, the optimal phase and amplitude of the current are searched again every 6 hours or longer to ensure that when the amplitude and phase of the refrigerator temperature fluctuation change, the active temperature control current can respond in time to achieve highly stable temperature control of the system.

[0065] The present invention will be described in detail below with reference to specific embodiments, and the active temperature control current on the secondary cold head 130 of the refrigerator will be used as an example for description and analysis.

[0066] Initially, the secondary cold head 130 of the refrigerator is at the lowest temperature of the system, 3.4K. Subsequently, the expected temperature point of the secondary cold head 130 of the refrigerator is adjusted to 5K.

[0067] Furthermore, the temperature sensor 310 on the secondary cold head 130 transmits the real-time temperature data of the secondary cold head 130 to the computer through the electrical measuring device. Based on the difference between the real-time temperature and the preset temperature, the heater 310 starts to output power and raises the temperature to about 5K. After the temperature stabilizes, the output power of the heater 310 is a constant value Q. heat .

[0068] Furthermore, the stabilized temperature of the secondary cold head 130 of the refrigerator is read, and the temperature fluctuation amplitude ΔT0, frequency f, and phase angle φ0 are analyzed on the computer side. The temperature of the secondary cold head 130 of the refrigerator is written as That is, at 5K, the temperature fluctuation amplitude ΔT0 of the secondary cold head 130 is 0.2K, the frequency f is 1.72Hz, and the phase angle φ0 is 0°.

[0069] Further, the optimal phase angle of the temperature control current is determined, and the heater 310 outputs an amplitude less than Q heat (Here we take 0.2W), the phase angle changes from 0° to 360°, and the sinusoidal current ΔQ changes every 45° heat After completing a cycle scan, the phase angle φ (270°) corresponding to the minimum temperature fluctuation at the temperature control point is the optimal phase, which is consistent with the theoretical calculation results. Figure 3 shown.

[0070] Furthermore, the phase angle of the temperature control current is fixed at 270°. According to the relevant parameters of the temperature fluctuation at the temperature control point of the secondary cold head 130, the theoretical optimal amplitude of the temperature control current is preliminarily determined. According to the mass of the refrigerator cold head of 1.6 kg and the heat capacity of 0.07 J / (kg·K), the temperature control current amplitude can be obtained. .

[0071] Furthermore, based on the theoretically calculated amplitude of 0.24W, the current amplitude scanning range is determined to be 0.18W~0.36W, and a scan is performed every 0.02W. The amplitude of 0.24W corresponding to the minimum temperature fluctuation at the temperature control point of the secondary cold head 130 is the optimal amplitude of the active temperature control current, which is consistent with the theoretical calculation results. Figure 4 shown.

[0072] Furthermore, the determined optimal angle 270° and the optimal amplitude 0.24W of the temperature control current are fed back to the heater 310 on the secondary cold head 130, so that the temperature control current is adjusted according to the The sine wave form is continuously output. Under this temperature control current, the temperature fluctuation amplitude is only 0.002K, which is attenuated by 99%.

[0073] The temperature fluctuation suppression device of this embodiment has at least the following beneficial effects: For the first time, active temperature control using a single current can simultaneously achieve the dual goals of reaching the desired temperature and attenuating temperature fluctuations. This simplifies experimental operation and solves the problem of the difficulty and cumbersome operation of using DC and AC currents to control temperature and temperature fluctuations respectively. Secondly, the influence of the phase angle and amplitude of the temperature control current on temperature control is taken into account at the same time, which solves the problem of incomplete temperature control current matching parameters and can obtain more efficient temperature control results; Thirdly, the temperature control parameter scanning program is used to achieve long-term continuous automation of the determination of the optimal temperature control current parameters, solving the problem that the current parameter determination cannot be automated and continuous, simplifying the operating procedures, and improving the efficiency of determining the optimal current parameters; Finally, a multi-stage joint temperature control method with multiple temperature control points is adopted, which not only attenuates temperature fluctuations at the source of temperature fluctuations, but also suppresses temperature fluctuations along the path and terminal of temperature fluctuation transmission. This solves the problem that single temperature control point temperature control cannot achieve all-round and efficient temperature control, and improves the temperature fluctuation suppression effect.

[0074] According to another aspect of the present invention, a method for suppressing temperature fluctuations is provided, comprising: adding the temperature fluctuation suppression device described in the above embodiment to a refrigerator, wherein the device comprises: A multi-layer sealed cavity surrounding the refrigeration components of the refrigerator; A heating assembly, the heating assembly comprising at least one heater, each heater corresponding to a temperature control point in any layer of the closed cavity, for heating the location of the temperature control point; A detection component, the detection component including a temperature sensor corresponding to each heater, for detecting the temperature at a location where the corresponding heater is located; A data processor is connected to the heating component and the detection component respectively, and is used to determine the phase and amplitude when the temperature fluctuation of the corresponding temperature control point is minimized according to the temperature detected by each temperature sensor, obtain the optimal phase and optimal amplitude and feed them back to the heater at the corresponding temperature control point.

[0075] The temperature fluctuation suppression method of this embodiment is to set up a multi-layer sealed cavity to surround the refrigeration component of the refrigerator, so that the internal sealed cavity is isolated from the external environment, and then use a heating component including at least one heater to heat the temperature control point in the sealed cavity to balance the temperature fluctuation of the refrigerator, and then use the temperature sensor corresponding to each heater to detect the temperature of the temperature control point, and then use the data processor to analyze the temperature fluctuation of the data returned by the temperature sensor, so as to find the optimal phase and optimal amplitude of the heater current that can minimize the temperature fluctuation of each temperature control point, so that the heater can ensure the stability of the temperature inside the sealed cavity in the optimal state, thereby achieving the suppression of temperature fluctuations and significantly improving the low-temperature constant temperature control effect.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A temperature fluctuation suppression device, characterized in that: The device comprises: A multi-layered sealed cavity surrounding the refrigeration components of the refrigerator; A heating component, wherein the heating component comprises at least one heater, each heater corresponding to a temperature control point in any layer of the closed cavity, and used for heating the position where the temperature control point is located; A detection component, the detection component includes a temperature sensor corresponding to each heater, and is used to detect the temperature at the location of the corresponding heater; A data processor is connected to the heating component and the detection component respectively, and is used to determine the phase and amplitude when the temperature fluctuation of the corresponding temperature control point is minimized according to the temperature detected by each temperature sensor, obtain the optimal phase and optimal amplitude and feed them back to the heater at the corresponding temperature control point.

2. The temperature fluctuation suppression device according to claim 1, characterized in that: The multi-layer sealed cavity includes a first sealed cavity, a second sealed cavity, a third sealed cavity and a fourth sealed cavity; The second sealed cavity is located inside the first sealed cavity, the third sealed cavity is located inside the second sealed cavity, and the fourth sealed cavity is located inside the third sealed cavity; The first sealed cavity surrounds the refrigerator head, the second sealed cavity surrounds the primary cold head of the refrigerator, the third sealed cavity surrounds the secondary cold head of the refrigerator, and the fourth sealed cavity serves as an experimental chamber.

3. The temperature fluctuation suppression device according to claim 2, characterized in that: The first sealed cavity comprises a first cylinder with an opening and a first-stage flange, the first-stage flange is connected to the head of the refrigerator, and the first-stage flange blocks the opening of the first cylinder; The second sealed cavity comprises a second cylinder with an opening and a second-stage flange, the second-stage flange is connected to a first-stage cold head of the refrigerator, and the second-stage flange blocks the opening of the second cylinder; The third sealed cavity comprises a third cylinder with an opening and a third-level flange, wherein the third-level flange is connected to the secondary cold head of the refrigerator, and the third-level flange blocks the opening of the third cylinder; The fourth sealed cavity includes a fourth cylinder with an opening and a fourth-stage flange. The fourth-stage flange is connected to the third-stage flange via a connecting shaft, and the fourth-stage flange blocks the opening of the fourth cylinder.

4. The temperature fluctuation suppression device according to claim 3, characterized in that: The first cylinder is made of stainless steel or aluminum, and the second cylinder, the third cylinder and the fourth cylinder are all made of copper or oxygen-free copper.

5. The temperature fluctuation suppression device according to claim 3, characterized in that: The heating assembly includes a first heater, a second heater and a third heater; The first heater is fixed on the secondary cold head of the refrigerator, the second heater is fixed on the third-stage flange, and the third heater is fixed on the fourth-stage flange.

6. The temperature fluctuation suppression device according to claim 5, characterized in that: The detection component includes a first temperature sensor, a second temperature sensor, a third temperature sensor and a fourth temperature sensor; The first temperature sensor corresponds to the first heater, the second temperature sensor corresponds to the second heater, the third temperature sensor corresponds to the third heater, the first temperature sensor is fixed on the secondary cold head of the refrigerator, the second temperature sensor is fixed on the third flange, and the third temperature sensor is fixed on the fourth flange.

7. The temperature fluctuation suppression device according to claim 1, characterized in that: Each heater in the heating assembly works by: A fixed current output is selected according to the temperature setting value to heat the corresponding temperature control point until the temperature is stable; and a current is output according to the optimal phase and optimal amplitude feedback from the data processor to heat the temperature control point.

8. The temperature fluctuation suppression device according to claim 7, characterized in that: The data processor determines the optimal phase for each heater by: Generating sinusoidal currents with different phase angles between 0 and 360° at fixed time intervals based on the fixed current, and applying each sinusoidal current to the heater at a fixed time; Performing temperature fluctuation analysis on the temperature data detected by the corresponding temperature sensor when the heater outputs sinusoidal currents with different phase angles, and taking the phase angle corresponding to the minimum temperature fluctuation as the optimal phase; The data processor determines the optimal amplitude for each heater by: Determining a theoretical amplitude based on the optimal phase, determining an amplitude scanning range according to the theoretical amplitude, and causing the heater to apply each amplitude within the amplitude scanning range at fixed time intervals; A temperature fluctuation analysis is performed on the temperature data detected by the corresponding temperature sensor when the heater applies various amplitudes, and the amplitude corresponding to the minimum temperature fluctuation is used as the optimal amplitude.

9. The temperature fluctuation suppression device according to claim 1, characterized in that: The data processor re-determines the optimal phase and the optimal amplitude for each heater at preset time intervals.

10. A method for suppressing temperature fluctuations, characterized in that: A temperature fluctuation suppression device as claimed in any one of claims 1 to 9 is added to the refrigerator.

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