Program cooling instrument

Abstract

The utility model relates to the technical field of biomedical treatment, and particularly discloses a programmed cooling instrument which comprises a sample cavity, a Stirling cryocooler, a thermoelectric refrigeration device, a heat exchange system and a control system. The sample cavity is located in the center of the top of the programmed cooling instrument and used for storing biological samples. The sample cavity performs graded refrigeration through double refrigeration sources of the thermoelectric refrigeration device and the Stirling cryocooler, smooth transition of the double refrigeration sources is achieved through the control system, and the functions of heat transfer and heat dissipation are achieved through the heat exchange system in the refrigeration process. The utility model aims to solve the problem that the performance of the existing single refrigeration source is limited in a wide temperature range. The method is mainly used for gradually cooling the biological sample in a specific temperature area according to a preset program.

Description

Technical Field

[0001] This utility model relates to the field of biomedical technology, and in particular to a programmed cooling device. Background Technology

[0002] A programmed cooling system is a key device for the cryopreservation of biological samples. By precisely controlling the cooling rate, it gradually cools the sample within a specific temperature range according to a preset program, thereby reducing intracellular ice crystal formation and osmotic pressure damage, and significantly improving cell recovery rates. Especially in the preservation of live cells, tissues, and biomolecules, programmed cooling systems need to achieve stable and controllable gradient cooling over a wide temperature range (such as room temperature to -196°C) to meet the differentiated cooling profile requirements of different biological samples.

[0003] In existing technologies, programmed cooling systems primarily rely on a single refrigeration source to achieve low-temperature control. For example, CN212057877U discloses a liquid nitrogen-free programmed cooling system based on a Stirling refrigerator, which achieves deep-temperature cooling (minus 196°C) through a Stirling cycle, avoiding the dependence on liquid nitrogen. However, its cooling efficiency and energy consumption control in the medium-to-high temperature range (such as above minus 60°C) are limited. On the other hand, CN205536658U proposes a thermoelectric cooling device that utilizes the Peltier effect combined with semiconductor materials to achieve precise temperature control, which is energy-saving and environmentally friendly. However, its cooling capacity is limited by the characteristics of semiconductor materials, making it difficult to cover ultra-low temperature requirements. Although the above technologies each have their advantages, they all use a single refrigeration source and have not solved the problem of adaptability of cooling performance over a wide temperature range.

[0004] The current technical challenge of programmed cooling systems lies in the fact that a single refrigeration source, limited by its operating principle, struggles to simultaneously meet the requirements of high-efficiency cooling, precise temperature control, and low energy consumption across a wide temperature range. For example, Stirling refrigerators perform exceptionally well in extremely low temperatures, but their energy consumption increases in the medium to high temperature range due to decreased thermodynamic efficiency; while thermoelectric refrigeration devices offer flexible temperature control in the medium to low temperature range, they cannot meet the demands of deep cryogenic conditions. Therefore, there is an urgent need for a programmed cooling system that can integrate the advantages of multiple refrigeration sources and achieve seamless integration across a wide temperature range to improve overall performance and applicability. Utility Model Content

[0005] To address the shortcomings of existing technologies, the present invention provides a programmable cooling device that overcomes the performance limitations of existing single cooling sources over a wide temperature range.

[0006] To solve the above problems, the technical solution adopted by this utility model is: a programmed cooling device, including a sample chamber, a Stirling refrigerator, a thermoelectric cooling device, and a heat exchange system; the sample chamber is located at the top center of the programmed cooling device and is used to store biological samples; the sample chamber is cooled in stages by dual cooling sources of thermoelectric cooling device and Stirling refrigerator, the thermoelectric cooling device is responsible for cooling above -60°C, and the Stirling refrigerator is responsible for cooling from -60°C to -196°C; the heat exchange system includes a water cooling system and an air cooling system, the water cooling system is used for heat dissipation at the hot end of the Stirling refrigerator, and the air cooling system includes a fan and a radiator shared with the water cooling system, the fan being located on the back of the programmed cooling device.

[0007] The technical principles underlying this solution are as follows: 1. Thermoelectric refrigeration devices are based on the Peltier effect. When a direct current passes through a circuit composed of two different conductors, one end absorbs heat and the other end releases heat, creating a temperature difference. Thermoelectric refrigeration devices have the advantages of fast response, precise temperature control, and low manufacturing cost, but also have the disadvantages of low thermoelectric conversion efficiency, limited cooling power, and difficulty in achieving extremely low temperature refrigeration. 2. Stirling refrigerators are based on the reverse Stirling cycle. They achieve the refrigeration effect by transferring heat from the cold temperature zone to the high temperature zone through the compression, expansion, and reheating process of the gas. Stirling refrigerators have the advantages of high-efficiency low-temperature refrigeration and suitability for extremely low-temperature refrigeration, but also have the disadvantages of slow start-up speed and high manufacturing cost.

[0008] Compared with existing technologies, the beneficial effects of this technical solution are: 1. This technical solution achieves staged refrigeration by working in tandem with the Stirling refrigerator and the thermoelectric refrigeration device, and the combination of the two overcomes the performance limitations of a single refrigeration source in a wide temperature range; 2. The two refrigeration sources in this application serve as backups for each other, and the other refrigeration source can still work normally when one refrigeration source is abnormal.

[0009] Furthermore, the Stirling refrigerator includes a Stirling cold end, a Stirling hot end, and a refrigerator; the Stirling cold end is in close contact with the bottom of the sample chamber; the Stirling hot end dissipates heat through a water cooling system; and the refrigerator is a mechanical refrigerator driven by electricity.

[0010] Furthermore, the thermoelectric cooling device includes a TEC cold end and a TEC hot end, with the TEC cold end in close contact with the bottom of the sample chamber; the TEC hot end dissipates heat through an air-cooling system.

[0011] Furthermore, the water cooling system includes a radiator, water pipes, a water pump, a water tank, and a water-cooling block. The radiator is a finned radiator fixed to the hot end of the Stirling circuit. The water pipes are spirally wound around the radiator. The water-cooling block is a metal block with internal water channels, which is tightly attached to the hot end of the Stirling circuit. The water tank is used to store circulating fluid, which flows after being pressurized by the water pump. The water pipes are used to connect the water pump, the water-cooling block, and the water tank, and their function is to allow the circulating fluid to circulate in a closed channel without leakage.

[0012] Furthermore, the heat exchange system also includes a thermal bridge, which is a T-shaped alumina block embedded in the bottom of the sample chamber. The horizontal section connects to the TEC cold end, and the vertical section connects to the Stirling cold end. The alumina block has high thermal conductivity, low-temperature resistance, and electrical insulation. Embedding the T-shaped alumina block can transfer heat while avoiding the risk of leakage. The T-shaped alumina block integrates the cold end of the thermoelectric refrigeration device and the Stirling cold end into a single heat conduction path, reducing thermal resistance and energy loss, and achieving efficient synergy between the two refrigeration sources.

[0013] Furthermore, the programmed cooling device has a sealed observation window at the top, facilitating observation of the state of the biological samples within the sample chamber.

[0014] Furthermore, the programmed cooling device also includes a control system, which comprises a control panel and temperature sensors. The control panel is mounted on the upper surface of the programmed cooling device, and the temperature sensors are respectively located inside the sample chamber, at the TEC cold end, the TEC hot end, the Stirling cold end, and the Stirling hot end. The control panel, mounted on the upper surface of the device, supports touch operation and real-time temperature curve display, facilitating direct setting of the cooling program and viewing of data. Based on data from multiple temperature sensors, it provides precise input to the control system, achieving high-precision temperature control and ensuring that the biological sample remains at the optimal cooling rate throughout the cooling process. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of this application.

[0016] Figure 2 This is a structural diagram of the Stirling refrigerator and thermoelectric refrigeration device of this application.

[0017] Figure 3 This is a schematic diagram of the heat exchange system layout in this application.

[0018] The reference numerals in the accompanying drawings of the instruction manual include: 1. Sample chamber; 11. Sealed observation window; 2. Stirling refrigerator; 21. Stirling cold end; 22. Stirling hot end; 23. Refrigerator; 3. Thermoelectric refrigeration device; 31. TEC cold end; 32. TEC hot end; 4. Heat exchange system; 41. Water cooling system; 411. Radiator; 412. Water pipe; 413. Water tank; 414. Water pump; 415. Water cooling block; 42. Fan; 43. Thermal bridge; 5. Control panel. Detailed Implementation

[0019] The following detailed description illustrates the specific implementation method:

[0020] As attached Figure 1-3 As shown: A programmed cooling device includes a sample chamber 1, a Stirling refrigerator 2, a thermoelectric cooling device 3, a heat exchange system 4, and a control system.

[0021] The sample chamber 1 is located at the top center of the programmed cooling instrument and is used to store biological samples; the upper part of the programmed cooling instrument has a sealed observation window 11.

[0022] The Stirling refrigerator 2 includes a Stirling cold end 21, a Stirling hot end 22, and a refrigerator 23; the Stirling cold end 21 is fixedly connected to the bottom of the sample chamber 1 and a heat-conducting bridge 43; the Stirling hot end 22 dissipates heat through a heat exchange system 4, and the refrigerator 23 is a mechanical refrigerator 23 driven by electricity.

[0023] The thermoelectric cooling device 3 includes a TEC cold end 31 and a TEC hot end 32. The TEC cold end 31 is fixedly connected to the bottom of the sample chamber 1 and a thermal bridge 43. The TEC hot end 32 dissipates heat through a heat exchange system 4.

[0024] The heat exchange system 4 includes a water cooling system 41, an air cooling system, and a heat-conducting bridge 43.

[0025] The water cooling system 41 is used for heat dissipation of the Stirling hot end 22, and includes a radiator 411, water pipes 412, a water pump 414, a water tank 413, and a water-cooled block 415. The radiator 411 is a finned radiator 411 and is fixed to the Stirling hot end 32. The water pipes 412 are spirally wound around the radiator 411. The water-cooled block 415 is a metal block with water channels inside, and the water-cooled block 415 is in close contact with the Stirling hot end 22. The water tank 413 is used to store circulating fluid, which flows after being pressurized by the water pump 414. The water pipes 412 are used to connect the water pump 414, the water-cooled block 415, and the water tank 413, and their function is to allow the circulating fluid to circulate in a closed channel without leakage.

[0026] The air-cooling system includes a fan 41 and a finned radiator 411 shared with the water-cooling system 41; the fan 41 is located on the back of the programmed cooling device, close to the radiator 411, for dissipating heat to the outside of the programmed cooling device.

[0027] The thermal bridge 43 is embedded in the T-shaped alumina block at the bottom of the sample chamber 1, with the horizontal section connected to the TEC cold end 31 and the vertical section connected to the Stirling cold end 21.

[0028] The control system uses a PID algorithm for control and includes a control panel 5 and sensors. The control panel 5 is installed on the upper surface of the programmable cooling instrument. The sensors are temperature sensors, which are respectively located inside the sample chamber 1, namely TEC cold end 31, TEC hot end 32, Stirling cold end 21, and Stirling hot end 22.

[0029] PID formula, control output It consists of three superimposed parts:

[0030]

[0031] The current error is (target value - actual value).

[0032] This is the coefficient for the proportional term (requires debugging and optimization).

[0033] The coefficients for the integral term (requires debugging and optimization).

[0034] These are the coefficients of the differential term (requires debugging and optimization).

[0035] PID control process:

[0036] Temperature measurement: Real-time temperature feedback via a temperature sensor.

[0037] Calculation error: Target temperature (program setting) - Actual temperature

[0038] Debugging and optimization:

[0039] Proportional term: Rapid response based on the current temperature difference;

[0040] Integral term: If the temperature difference persists for a long period, it will be gradually compensated;

[0041] Differential term: If the temperature drops too quickly, reduce the cooling power in advance.

[0042] Execution result: The PID output signal controls the power of Stirling refrigerator 2 and thermoelectric refrigeration device 3.

[0043] Work process:

[0044] When the programmed cooling device is working, the thermoelectric refrigeration unit 3 first works, using its rapid response and precise temperature control characteristics to initially cool down to -60°C. When the temperature of the thermoelectric refrigeration unit 3 reaches -60°C, the Stirling refrigerator 2 is switched as the main cold source to achieve deep cooling (from -60°C to -196°C).

[0045] During the switching process, the thermoelectric refrigeration unit 3 gradually reduces its power, and the Stirling refrigerator 2 starts up and takes over the refrigeration, with a smooth transition achieved through a PID algorithm.

[0046] During the cooling process of Stirling refrigerator 2, thermoelectric refrigeration device 3 can also switch to fine-tuning mode to compensate for temperature fluctuations of Stirling refrigerator 2 and ensure that biological samples are always at the optimal rate during the cooling process.

[0047] When one of the cooling sources in a programmed cooling system fails, the other cooling source can still function normally.

[0048] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A programmed cooling device, characterized in that: The device includes a sample chamber, a Stirling refrigerator, a thermoelectric refrigeration unit, and a heat exchange system. The sample chamber, located at the top center of the programmed cooling instrument, is used to store biological samples. The sample chamber is cooled in stages using a dual-source cooling system: a thermoelectric refrigeration unit and a Stirling refrigerator. The thermoelectric refrigeration unit is responsible for cooling above -60°C, while the Stirling refrigerator is responsible for cooling from -60°C to -196°C. The heat exchange system includes a water-cooling system and an air-cooling system. The water-cooling system is used for heat dissipation from the hot end of the Stirling refrigerator, and the air-cooling system includes a fan and a radiator shared with the water-cooling system. The fan is located on the back of the programmed cooling instrument.

2. The programmed cooling device according to claim 1, characterized in that: The Stirling refrigerator includes a Stirling cold end, a Stirling hot end, and a refrigerator; the Stirling cold end is in close contact with the bottom of the sample chamber; the Stirling hot end dissipates heat through a water cooling system; and the refrigerator is a mechanical refrigerator driven by electricity.

3. The programmed cooling device according to claim 1, characterized in that: The thermoelectric cooling device includes a TEC cold end and a TEC hot end. The TEC cold end is in close contact with the bottom of the sample chamber; the TEC hot end dissipates heat through an air-cooling system.

4. The programmed cooling device according to claim 1, characterized in that: The water cooling system includes a radiator, water pipes, a water pump, a water tank, and a water-cooled block. The radiator is a finned radiator fixed to the hot end of the Stirling circuit. The water pipes are spirally wound around the radiator. The water-cooled block is a metal block with internal water channels, which is tightly attached to the hot end of the Stirling circuit. The water tank is used to store circulating fluid, which flows after being pressurized by the water pump. The water pipes are used to connect the water pump, the water-cooled block, and the water tank, and their function is to allow the circulating fluid to circulate in a closed channel without leakage.

5. A programmed cooling device according to claim 1, characterized in that: The heat exchange system also includes a thermal bridge, which is a T-shaped alumina block embedded in the bottom of the sample chamber, with the horizontal section connected to the TEC cold end and the vertical section connected to the Stirling cold end.

6. The programmed cooling device according to claim 1, characterized in that: The programmable cooling device has a sealed observation window on its upper part.

7. The programmed cooling device according to claim 1, characterized in that: The programmed cooling device also includes a control system, which includes a control panel and temperature sensors. The control panel is mounted on the upper surface of the programmed cooling device, and the temperature sensors are respectively located inside the sample chamber, at the TEC cold end, the TEC hot end, the Stirling cold end, and the Stirling hot end.

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