Temperature fluctuation suppression device and method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TECHNICAL INST OF PHYSICS & CHEMISTRY - CHINESE ACAD OF SCI
- Filing Date
- 2024-08-29
- Publication Date
- 2026-07-21
Smart Images
Figure CN119148791B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of information management technology, and in particular to a temperature fluctuation suppression device and method. Background Technology
[0002] The cryogenic region (below 120K) is a crucial temperature range for engineering applications in aerospace, high-energy physics, quantum science, and other large-scale scientific technologies. The temperature stability in this region directly impacts the performance of cryogenic control systems. Cryogenic control systems typically use small, continuously operating refrigerators (NOTs) with low operating costs, no need to consume cryogenic liquids, and the ability to provide cooling. Due to the working principle and structure of these refrigerators, their working fluid (usually helium) undergoes periodic expansion during operation, resulting in inherent temperature fluctuations. These fluctuations cannot meet the requirements of high-precision experiments for a stable temperature environment. Therefore, cryogenic control systems using refrigerators as their cooling source need to address the inherent temperature fluctuations of the refrigerators.
[0003] Currently, the common method for suppressing inherent temperature fluctuations in refrigeration units is to optimize the system structure to achieve passive temperature decay. However, this method is difficult to achieve the desired temperature and temperature fluctuations. Another active temperature control method suppresses the original temperature fluctuations of the refrigeration unit by adjusting the heating output of the heaters on the controlled components. 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, requiring coordinated control of both currents to achieve the target, which is cumbersome and prone to incoordination. Second, only the matching of the phase angle between the temperature control current and the temperature fluctuation is considered, without considering the matching of the magnitude of the temperature control current with the amplitude of the temperature fluctuation, making it difficult to obtain efficient temperature control results. Third, determining the phase angle of the temperature control current requires equal phase division and matching, which is complex and difficult to automate and sustain over a long period. Fourth, the temperature control point is only at the cold source of the refrigeration unit, without considering active temperature control at other control points that are reached along with the temperature fluctuations due to the transfer of cold energy, failing to achieve multi-stage joint temperature control.
[0004] Invention Content
[0005] This invention provides a temperature fluctuation suppression device and method to solve the problems of complex dual-current coordinated temperature control, incomplete temperature control current matching parameters, difficulty in determining the optimal temperature control current parameters, and lack of automation in existing active temperature control. By using a single current to automatically adjust the optimal value of the phase and amplitude of the temperature control current at multiple temperature control points, high temperature stability control in low-temperature constant temperature devices can be 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-layered, sealed cavity surrounding the refrigeration components of a refrigeration machine; A heating assembly, comprising at least one heater, each heater corresponding to a temperature control point within any sealed cavity, for heating the location of the temperature control point; A detection component, comprising a temperature sensor corresponding to each heater, for detecting the temperature at the location of the corresponding heater; A data processor, which is connected to the heating component and the detection component respectively, is used to determine the phase and amplitude that minimize the temperature fluctuation at the corresponding temperature control point based on 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-layered 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 compressor head, the second sealed cavity surrounds the primary cold head of the compressor, the third sealed cavity surrounds the secondary cold head of the compressor, and the fourth sealed cavity serves as the 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 being connected to the head of the refrigeration unit and sealing 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 refrigeration unit and blocks the opening of the second cylinder. The third sealed cavity includes a third cylinder with an opening and a third-stage flange. The third-stage flange is connected to the second-stage cold head of the refrigeration unit, and the third-stage flange seals the opening of the third cylinder. The fourth sealed cavity includes a fourth cylinder with an opening and a fourth-level flange. The fourth-level flange is connected to the third-level flange via a connecting shaft, and the fourth-level flange seals the opening of the fourth cylinder.
[0009] In some possible implementations, the first cylinder is made of stainless steel or aluminum, and the second, third and fourth cylinders 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 refrigeration unit, 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 second stage cold head of the refrigeration unit, the second temperature sensor is fixed on the third stage flange, and the third temperature sensor is fixed on the fourth stage flange.
[0012] In some possible implementations, each heater in the heating assembly operates through the following steps: A fixed current output is selected based on the temperature setpoint to heat the corresponding temperature control point to a stable temperature; and a current is output based on 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 for each heater determines the optimal phase through the following steps: Based on the fixed current, sinusoidal currents with different phase angles between 0 and 360° are generated at fixed time intervals, and each sinusoidal current is applied to the heater at fixed times. Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when the heater outputs sinusoidal current with different phase angles, and the phase angle corresponding to the minimum temperature fluctuation is taken as the optimal phase. For each heater, the data processor determines the optimal amplitude through the following steps: Based on the optimal phase, the theoretical amplitude is determined, the amplitude scanning range is determined according to the theoretical amplitude, and the heater is instructed to apply each amplitude within the amplitude scanning range at fixed time intervals. Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when applying various amplitude values to the heater, and the amplitude corresponding to the minimum temperature fluctuation is taken as the optimal amplitude.
[0014] In some possible implementations, the data processor for each heater redetermines the optimal phase and optimal amplitude at preset time intervals.
[0015] According to a second aspect of the present invention, the present invention also provides a method for suppressing temperature fluctuations, the method comprising: adding the temperature fluctuation suppression device described above to a refrigeration unit.
[0016] This invention provides a temperature fluctuation suppression device and method. By setting up multiple layers of sealed cavities to surround the refrigeration components of a refrigerator, the internal sealed cavities are isolated from the external environment. Then, a heating assembly including at least one heater is used to heat the temperature control points within the sealed cavities to balance the temperature fluctuations of the refrigerator. Next, temperature sensors corresponding to each heater detect the temperature of the temperature control points. Then, a data processor analyzes the temperature fluctuation data returned by the temperature sensors to find the optimal phase and optimal amplitude of the heater current that minimizes the temperature fluctuations at each temperature control point. This ensures that the heaters are in optimal condition to maintain the temperature stability inside the sealed cavities, thereby suppressing temperature fluctuations and significantly improving the low-temperature constant temperature control effect. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the temperature fluctuation suppression device provided by the present invention.
[0019] Figure 2 This is a schematic diagram of the internal structure of the multi-layered sealed cavity provided by the present invention.
[0020] Figure 3 The temperature control results provided by this invention are the temperature control results under different phase angles of the temperature control current.
[0021] Figure 4 The temperature control results provided by this invention are the temperature control results under different amplitudes of the temperature control current.
[0022] [Explanation of Labels in the Attached Image]
[0023] 100: Refrigeration head; 110: Refrigeration unit; 120: Primary cold head; 130: Secondary cold head; 140: Connecting shaft; 200: Multi-layered sealed cavity; 210: First sealed cavity; 211: First cylindrical body; 212: First-stage flange; 220: Second sealed cavity; 221: Second cylinder; 222: Second-stage flange; 230: Third sealed cavity; 231: Third cylinder; 232: Third flange; 220: Fourth sealed cavity; 241: Fourth cylinder; 242: Fourth 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 Implementation
[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0025] The following is combined Figures 1 to 4 This invention describes a temperature fluctuation suppression device and a temperature fluctuation suppression method.
[0026] Figure 1 This is a schematic diagram of the temperature fluctuation suppression device provided by the present invention. Please refer to it. Figure 1 As shown, this embodiment provides a temperature fluctuation suppression device, which comprises four parts: a multi-layer sealed cavity 200, a heating component 300, a detection component 400, and a data processor 500. The following will describe each component in detail: The multi-layered sealed cavity 200 surrounds the refrigeration components of the refrigerator 110; wherein, the multi-layered sealed cavity 200 refers to a multi-layered structure formed by nesting cavities from the inside out. Each layer of the multi-layered sealed cavity 200 is a sealed cavity. It should be noted that the number of layers of the multi-layered sealed cavity 200 can be greater than or equal to two. In specific implementation, considering the installation process and the requirements for constant temperature accuracy, the multi-layered sealed cavity can adopt a three- to six-layer sealed cavity structure.
[0027] It should be noted that, Figure 1 Although the refrigerator 110 is shown, the refrigerator 110 is not a 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 assembly 300 includes at least one heater, each heater corresponding to a temperature control point in any layer of sealed cavity. Typically, it is installed at the cold head of the refrigeration unit or on flanges at various levels to heat the location of the temperature control point. The heater is fixed to the corresponding temperature control point.
[0029] In this embodiment, a temperature control point refers to a location within the sealed cavity where a heater is needed for temperature regulation. An arbitrary number of temperature control points can be set within a single sealed cavity. The number of temperature control points can be determined based on the distance between each layer of sealed cavities and the innermost experimental chamber. For example, in a five-layer sealed cavity, where the innermost layer is the experimental chamber, multiple temperature control points can be set in the third and fourth layers respectively. No temperature control points need to be set in the outermost sealed cavity. It should be noted that the number and location of temperature control points in this embodiment are for illustrative purposes only and should not be construed as limiting the scope of the invention.
[0030] The detection component 400 includes a temperature sensor corresponding to each heater for detecting the temperature at the location of the corresponding heater.
[0031] In the specific implementation process, the temperature sensor can be fixed on the component used to fix the heater. The distance between the sensor and the heater can be set according to the experimental conditions. The temperature sensor measures the temperature of the control point by measuring the temperature of the fixed component. Alternatively, multiple temperature sensors can be set at a unified measurement point and the data results can be weighted and averaged to ensure the uniformity and accuracy of the temperature data.
[0032] A data processor 500 is connected to the heating component 300 and the detection component 400 respectively. It is used to determine the phase and amplitude that minimizes the temperature fluctuation at the corresponding temperature control point based on 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 in this embodiment surrounds the refrigeration components of the refrigerator with multiple layers of sealed cavities, isolating the sealed cavities from the external environment. Then, a heating assembly including at least one heater heats the temperature control points within the sealed cavities to balance the temperature fluctuations of the refrigerator. Next, temperature sensors corresponding to each heater detect the temperature of the temperature control points. A data processor then analyzes the temperature fluctuation data returned by the temperature sensors to find the optimal phase and amplitude of the heater current that minimizes temperature fluctuations at each temperature control point. This ensures that the heaters operate in optimal condition to maintain temperature stability within the sealed cavities, thereby suppressing temperature fluctuations and significantly improving the low-temperature constant temperature control effect.
[0034] For some possible implementations, please refer to 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 sequentially. In practice, to ensure effective temperature control, the sealed cavities of adjacent layers do not come into contact with each other. Each sealed cavity layer can have the same shape, such as all four sealed cavities being rectangular or spherical, etc.
[0035] The first sealed cavity 210 surrounds the head 100 of the refrigerator 110, the second sealed cavity 220 surrounds the first-stage cold head 120 of the refrigerator 110, the third sealed cavity 230 surrounds the second-stage cold head 130 of the refrigerator 110, and the fourth sealed cavity 240 serves as an experimental chamber.
[0036] The temperature fluctuation suppression device in this embodiment has four layers of multi-layer sealed cavities. The outer three layers of sealed cavities surround the compressor head and two-stage cold heads in sequence, and the innermost fourth layer of sealed cavities serves as the experimental chamber. This not only isolates the external environment from the temperature of the experimental chamber, but also adapts to the cooling components of the compressor, reducing the influence of the external environment and the compressor on the temperature of the innermost experimental chamber.
[0037] In some possible implementations, please refer again. Figure 2 As shown, the first sealed cavity 210 includes a first cylindrical body 211 with an opening and a first-stage flange 212. The first-stage flange 212 is connected to the head 100 of the refrigeration unit 110, and the first-stage flange 212 blocks the opening of the first cylindrical body 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 refrigeration unit 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-stage flange 232. The third-stage flange 232 is connected to the second-stage cold head 130 of the refrigeration unit 110, and the third-stage 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 in this embodiment is constructed with all four sealed cavities in the form of a combination of cylinder and flange, which allows the temperature fluctuation suppression device to be quickly and easily assembled with the refrigeration unit, 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] In some possible implementations, please refer again. 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 on the secondary cold head 130 of the refrigeration unit 110, the second heater 320 is fixed on the third flange 232, and the third heater 330 is fixed on the fourth flange 242.
[0041] The temperature fluctuation suppression device in this embodiment, for a four-layer sealed cavity structure, installs heaters on the flanges at the sealing points of the secondary cold head and the two inner cavity layers, respectively. That is, two temperature control points are selected in the second sealed cavity and one temperature control point is selected in the third sealed cavity, thus achieving a reasonable and effective setting of temperature control points.
[0042] In some possible implementations, please refer again. 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 refrigeration unit 110, the second temperature sensor 420 is fixed on the third flange 232, and the third temperature sensor 430 is fixed on the fourth flange 242.
[0043] The temperature fluctuation suppression device in this embodiment sets temperature sensors at the three selected temperature control points to measure the temperature at the corresponding temperature control points, thereby enabling real-time monitoring of the impact of each heater on the temperature after it starts working, and providing reliable data support for subsequent heater control.
[0044] In some possible implementations, each heater in the heating assembly 300 operates through the following steps: A fixed current output is selected based on the temperature setpoint to heat the corresponding temperature control point until the temperature stabilizes; and
[0045] In this embodiment, the temperature stability value does not mean that the temperature is stable at a certain value. Temperature stability means that the temperature deviation relative to a certain value continues to be within a set range, that is, no longer a large temperature deviation occurs.
[0046] The data processor 500 outputs current based on the optimal phase and amplitude feedback to heat the temperature control point.
[0047] In this embodiment of the temperature fluctuation suppression device, each heater is configured to first heat to a relative temperature using a fixed current, and then apply the optimal amplitude and optimal phase feedback from the data processor to achieve accurate control of the operating state of each heater.
[0048] In some possible implementations, the data processor 500 determines the optimal phase for each heater through the following steps: Based on the fixed current, sinusoidal currents with different phase angles between 0 and 360° are generated at fixed time intervals, and each sinusoidal current is applied to the heater at fixed times. In practical implementation, to ensure the data processor's efficiency in finding the optimal phase, it can be set to start from zero degrees, using a fixed phase difference as the step size, until the phase reaches 360°. In practice, when higher temperature stability accuracy is required, the phase difference step size can be set relatively small, such as 15°. When lower accuracy is required, to ensure search efficiency, the phase difference step size can be set relatively large, such as 45°. It should be noted that the fixed time interval should ensure the current output has at least one complete cycle.
[0049] Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when the heater outputs sinusoidal current with different phase angles, and the phase angle corresponding to the minimum temperature fluctuation is taken as the optimal phase. For each heater, the data processor 500 determines the optimal amplitude through the following steps: Based on the optimal phase, the theoretical amplitude is determined, the amplitude scanning range is determined according to the theoretical amplitude, and the heater is instructed to apply each amplitude within the amplitude scanning range at fixed time intervals. In practical implementation, the theoretical amplitude is a fixed amplitude, while 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 the interval consisting of all amplitudes whose deviation from the theoretical amplitude does not exceed 0.1, i.e., [1.0, 1.2]. To ensure the efficiency of the data processor in finding the optimal amplitude, for each amplitude within the amplitude scanning range, a fixed amplitude difference can be set starting from the smallest boundary until the phase reaches the maximum boundary value of the amplitude. In practical implementation, when higher temperature stability accuracy is required, the amplitude difference can be set relatively small, such as with a step size of 0.01. When lower accuracy is required, the amplitude difference can be set relatively large to ensure search efficiency, such as with a step size of 0.5. Similarly, the fixed time interval should ensure that the current output has at least one complete cycle.
[0050] Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when applying various amplitude values to the heater, and the amplitude corresponding to the minimum temperature fluctuation is taken as the optimal amplitude.
[0051] The temperature fluctuation suppression device in this embodiment further provides a method for the data processor to find the optimal amplitude and phase. It iterates through different phase intersections and amplitudes in a specific manner, using the data processor to analyze temperature fluctuations and thus determine the optimal control state of each heater, achieving high accuracy. Simultaneously, it considers the influence of the phase angle and amplitude of the temperature control current on temperature control, solving the problem of incomplete temperature control current matching parameters and obtaining more efficient temperature control results.
[0052] In some possible implementations, the data processor 500 for each heater redetermines the optimal phase and optimal amplitude at preset time intervals.
[0053] In the specific implementation process, a timer or counter can be used to detect the preset time interval. For example, if the preset time interval is 6 hours, then every 6 hours, the data processor will re-determine the optimal phase and optimal amplitude for each heater.
[0054] The temperature fluctuation suppression device in this embodiment improves the temperature fluctuation suppression effect and has better stability by having the data processor repeatedly search for the optimal phase and optimal amplitude for each heater at preset time intervals.
[0055] In yet another embodiment, for ease of understanding of the present invention, the following will continue to use... Figure 2 Taking the temperature fluctuation suppression device with four sealed cavities shown as an example, the working process of using the temperature fluctuation device to achieve low temperature control will be explained in detail below: First, based on the temperature setpoint, the heater outputs a fixed current to reach a temperature close to the preset temperature.
[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 shorter intervals. After the current phase completes a full cycle, the phase angle corresponding to the minimum temperature fluctuation at the temperature control point is the optimal phase. This optimal phase angle is fed back to the heater's power signal, causing the power signal to continuously output the determined optimal phase.
[0057] Subsequently, based on the optimal phase angle, the optimal amplitude of the temperature control current is determined. The current amplitude scanning 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 amplitude of the active temperature control current. This optimal amplitude is fed back to the heater's power signal, ensuring continuous output of the determined optimal amplitude.
[0058] Finally, the optimal phase and amplitude of the current are re-found every 6 hours or longer to ensure that the active temperature control current can respond in a timely manner when the amplitude and phase of the refrigerator temperature fluctuations change, thereby achieving high-stability temperature control of the system.
[0059] Taking the secondary cold head of a refrigeration unit as an example, this paper explains the theoretical calculation method for the optimal phase and amplitude of the active temperature control current. For the cold head of a refrigeration unit, its thermal balance can be expressed by the following formula: Formula 1; Where M represents the mass of the refrigeration unit's cold head, in kg; C represents the heat capacity of the refrigeration unit's materials, in J / (kg·K); T aim It is the target temperature for temperature control, expressed in Kelvin (K). This is the heating capacity of the heater, measured in W. This refers to the cooling capacity of the refrigeration unit, measured in watts (W). , , These represent fluctuations in temperature, heat, and cold, respectively.
[0060] Once the target temperature is reached and stabilized, Equation 1 can be written as Equations 2 and 3.
[0061] Formula 2; Formula 3; Among them, heating amount The magnitude is determined based on the set temperature. The heat and temperature fluctuation values can be represented by a sine function, as shown in Equation 4 below: Formula 4; in, Indicates heating amount phase angle, The phase angle represents the temperature of the refrigeration unit's cold head.
[0062] The combined formulas 2 to 4 yield the following: Formula 5; Based on the relationship between 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 theoretically optimal amplitude of the temperature-controlling current can be determined based on data such as the material mass and initial temperature fluctuation at the temperature control point. The optimal phase of the temperature-controlling current differs from the phase of the temperature fluctuation at the temperature control point by 270°. However, in actual experiments, due to the presence of structural thermal resistance and contact thermal resistance, there is a delay in the system response, and the response time varies between different systems. Therefore, it is still necessary to accurately determine the optimal phase angle of the temperature-controlling current through experiments.
[0064] Continuing with the example of the heater on the secondary cooling head 130, and using a computer as the data processor, taking the heater 310 on the secondary cooling head 130 as an example, the method for determining the optimal phase angle and optimal amplitude is as follows: First, the temperatures of the secondary cold head 130, the tertiary flange 232, and the quaternary flange 242 are collected using three temperature data sensors and transmitted to a computer via electrical measuring equipment. Based on the set expected temperature, the heater continuously outputs power. Raise / lower the temperature to the preset temperature point; Furthermore, once the preset temperature is reached, the temperatures of the secondary cold head 130, the tertiary flange 232, and the quaternary flange 242 will be collected and analyzed on the computer for temperature fluctuation amplitude ΔT0, frequency f, and phase angle φ0. This can be achieved using formulas. To represent; Furthermore, the heater 310 on the secondary cold head 130 has an existing heating capacity. Based on this, a sinusoidal current ΔQ with a phase angle ranging from 0° to 360° is generated at regular intervals. heat After completing a full cycle of scanning, 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 is continuously output at the determined optimal phase angle φ; Furthermore, based on the relevant parameters of temperature fluctuation at the 130 temperature control point of the secondary cold head, the theoretical optimal amplitude of the temperature control current is initially determined, according to the formula... Perform calculations; Furthermore, the current amplitude scanning range is determined based on the theoretically calculated amplitude ΔQ0. Each amplitude is scanned for one cycle. The amplitude corresponding to the minimum temperature fluctuation at the 5th temperature control point of the 130 temperature control point of the secondary cold head 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 is continuously output with the determined optimal amplitude; Furthermore, the optimal phase and amplitude of the temperature control current on the third-level flange 232 and the fourth-level flange 242 are determined sequentially and fed back to their respective heaters 310 to continuously output the optimal phase and amplitude of the current. Furthermore, the optimal phase and amplitude of the current are re-identified every 6 hours or longer to ensure that the active temperature control current can respond promptly when the amplitude and phase of the refrigerator temperature fluctuations change, thereby achieving high-stability temperature control of the system.
[0065] The present invention will now be described in detail with reference to specific embodiments, taking the active temperature control current on the secondary cold head 130 of the refrigeration unit as an example for explanation and analysis.
[0066] Initially, the secondary cooling head 130 of the refrigerator was at its lowest system temperature of 3.4K, and then the expected temperature point of the secondary cooling head 130 was adjusted to 5K.
[0067] Furthermore, the temperature sensor 310 on the secondary cooling head 130 transmits the real-time temperature data of the secondary cooling head 130 to the computer via an electrical measuring device. Based on the difference between the real-time temperature and the preset temperature, the heater 310 begins to output power, raising the temperature to approximately 5K. After the temperature stabilizes, the heater 310 outputs a fixed power value Q. heat .
[0068] Furthermore, the stable temperature of the secondary cooling head 130 of the refrigerator is read, and the temperature fluctuation amplitude ΔT0, frequency f, and phase angle φ0 are analyzed on the computer. The temperature of the secondary cooling head 130 of the refrigerator is written as follows: 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] Furthermore, the optimal phase angle of the temperature control current is determined, and the heater 310 outputs a current with an amplitude less than Q. heat (Take 0.2W here), a sinusoidal current ΔQ with a phase angle varying from 0° to 360°, changing every 45°. heat After completing one cycle of scanning, the phase angle φ (270°) corresponding to the minimum temperature fluctuation at the temperature control point is the optimal phase, consistent with the theoretical calculation result. Figure 3 As shown.
[0070] Furthermore, the phase angle of the temperature control current is fixed at 270°. Based on the relevant parameters of temperature fluctuation at the 130° temperature control point of the secondary cold head, the theoretical optimal amplitude of the temperature control current is initially determined. Calculated with a cold head mass of 1.6 kg and a heat capacity of 0.07 J / (kg·K), the amplitude of the temperature control current can be obtained. .
[0071] Furthermore, based on the theoretically calculated amplitude of 0.24W, the current amplitude scanning range was determined to be 0.18W~0.36W, with a scan performed every 0.02W. The amplitude of 0.24W corresponding to the minimum temperature fluctuation at the 130 temperature control point of the secondary cold head is the optimal amplitude of the active temperature control current, consistent with the theoretical calculation results. Figure 4 As shown.
[0072] Furthermore, the determined optimal angle of the temperature control current (270°) and the optimal amplitude (0.24W) are fed back to the heater 310 on the secondary cold head 130, so that the temperature control current follows the specified parameters. The output is continuously in the form of a sine wave. 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 objectives of reaching the expected temperature and attenuating temperature fluctuations, simplifying experimental operation and solving the problems of high difficulty and cumbersome operation in coordinating the control of temperature and temperature fluctuations with DC and AC currents respectively. Secondly, the influence of the phase angle and amplitude of the temperature control current on temperature control is considered simultaneously, which solves the problem of incomplete matching parameters of the temperature control current and can obtain more efficient temperature control results. Furthermore, by adopting a temperature control parameter scanning program, the long-term continuous automation of determining the optimal temperature control current parameter is realized, which solves the problem that the determination of current parameters cannot be automated and continuous, simplifies the operation procedure, and improves the efficiency of determining the optimal current parameter. Finally, a multi-level 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 at the end 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 a temperature fluctuation suppression device as described in the above embodiments to a refrigerator, the device comprising: A multi-layered, sealed cavity surrounding the refrigeration components of a refrigeration machine; A heating assembly, comprising at least one heater, each heater corresponding to a temperature control point within any sealed cavity, for heating the location of the temperature control point; A detection component, comprising a temperature sensor corresponding to each heater, for detecting the temperature at the location of the corresponding heater; A data processor, which is connected to the heating component and the detection component respectively, is used to determine the phase and amplitude that minimize the temperature fluctuation at the corresponding temperature control point based on 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 in this embodiment surrounds the refrigeration components of the refrigerator with multiple layers of sealed cavities, isolating the sealed cavities from the external environment. Then, a heating assembly including at least one heater heats the temperature control points within the sealed cavities to balance the temperature fluctuations of the refrigerator. Next, temperature sensors corresponding to each heater detect the temperature of the temperature control points. A data processor then analyzes the temperature fluctuation data returned by the temperature sensors to find the optimal phase and amplitude of the heater current that minimizes temperature fluctuations at each temperature control point. This ensures that the heaters operate in optimal condition to maintain temperature stability within the sealed cavities, thereby suppressing 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, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A temperature fluctuation suppression device, characterized in that, The device includes: A multi-layered, sealed cavity surrounding the refrigeration components of a refrigeration machine; A heating assembly, comprising at least one heater, each heater corresponding to a temperature control point within any sealed cavity, for heating the location of the temperature control point; A detection component, comprising a temperature sensor corresponding to each heater, for detecting the temperature at the location of the corresponding heater; A data processor, which is connected to the heating component and the detection component respectively, is used to determine the phase and amplitude that minimize the temperature fluctuation at the corresponding temperature control point based on 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. Each heater in the heating assembly operates through the following steps: A fixed current output is selected based on the temperature setpoint to heat the corresponding temperature control point to a stable temperature; and a current is output based on the optimal phase and optimal amplitude feedback from the data processor to heat the temperature control point. For each heater, the data processor determines the optimal phase through the following steps: Based on the fixed current, sinusoidal currents with different phase angles between 0 and 360° are generated at fixed time intervals, and each sinusoidal current is applied to the heater at fixed times. Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when the heater outputs sinusoidal current with different phase angles, and the phase angle corresponding to the minimum temperature fluctuation is taken as the optimal phase. For each heater, the data processor determines the optimal amplitude through the following steps: Based on the optimal phase, the theoretical amplitude is determined, the amplitude scanning range is determined according to the theoretical amplitude, and the heater is instructed to apply each amplitude within the amplitude scanning range at fixed time intervals. Temperature fluctuation analysis is performed on the temperature data detected by the temperature sensor when applying various amplitude values to the heater, and the amplitude corresponding to the minimum temperature fluctuation is taken as the optimal amplitude. ； ； in, This represents the amplitude of temperature fluctuation. For frequency, For the quality of the refrigeration unit's cold head, For the heat capacity of the refrigeration machine material, This is the theoretical amplitude; For optimal phase, For the phase of temperature fluctuation at the control point, This represents the phase difference.
2. The temperature fluctuation suppression device according to claim 1, characterized in that, The multi-layered 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 compressor head, the second sealed cavity surrounds the primary cold head of the compressor, the third sealed cavity surrounds the secondary cold head of the compressor, and the fourth sealed cavity serves as the experimental chamber.
3. The temperature fluctuation suppression device according to claim 2, characterized in that, 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 refrigeration unit and seals 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 refrigeration unit and blocks the opening of the second cylinder. The third sealed cavity includes a third cylinder with an opening and a third-stage flange. The third-stage flange is connected to the second-stage cold head of the refrigeration unit, and the third-stage flange seals the opening of the third cylinder. The fourth sealed cavity includes a fourth cylinder with an opening and a fourth-level flange. The fourth-level flange is connected to the third-level flange via a connecting shaft, and the fourth-level flange seals 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, while the second, third, and fourth cylinders 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 refrigeration unit, 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, and the third temperature sensor corresponds to the third heater. The first temperature sensor is fixed on the second stage cold head of the refrigeration unit, the second temperature sensor is fixed on the third stage flange, and the third temperature sensor is fixed on the fourth stage flange.
7. The temperature fluctuation suppression device according to claim 1, characterized in that, For each heater, the data processor redetermines the optimal phase and optimal amplitude at preset time intervals.