Constant temperature bath and constant temperature method

Abstract

The invention relates to the field of equipment verification, in particular to a thermostatic bath and a thermostatic method. The constant temperature bath comprises at least one constant temperature bath unit, the magnetic stirrer is rotationally arranged at the inner bottom of the tank body, the cooling fan is arranged at the outer bottom of the tank body, the magnet is arranged on the cooling fan and rotates along with the cooling fan, the semiconductor chilling plate wraps the periphery of the tank body and the periphery of the cooling fan, and the cooling fin is attached to the semiconductor chilling plate. The size of the calorimeter temperature sensor calibrating device is reduced, the operation efficiency and the automation degree are improved, and the temperature can be uniformly controlled.

Description

Technical Field

[0001] The present invention relates to the field of equipment verification, and particularly to a constant temperature bath and a constant temperature method. Background Art

[0002] With the gradual promotion of the urban heating system reform and the household heating metering and charging policy, as an important metering device in the heating system, the accuracy and reliability of heat meters have received extensive attention. A heat meter calculates the heat transfer amount by measuring the flow rate and temperature difference of the fluid, and the accuracy of the temperature sensor directly affects the measurement result of the heat meter. Therefore, the factory verification and regular calibration of the heat meter temperature sensor become particularly important.

[0003] The existing heat meter temperature sensor verification devices are mainly composed of a flow verification device and a temperature verification device. For example, the patent number CN205373921U discloses a standard meter method heat meter automatic verification device, which realizes the automatic verification of the heat meter through components such as a constant temperature water tank, a water pump, a flow meter, and a temperature sensor. However, the following problems still exist in the actual application of the existing technology: Large equipment volume: Traditional verification devices require multiple independent constant temperature baths for calibration at different temperature points. For example, to achieve three different temperature differences, multiple constant temperature baths may be required, which results in a large floor area for the equipment and is not convenient for installation and operation.

[0004] Low operating efficiency: When switching between different temperature points in the existing device, the temperature of a single constant temperature bath needs to be adjusted multiple times. Since temperature is an inert parameter and the heating and cooling speed is very slow, each temperature adjustment takes a long time, resulting in low verification efficiency.

[0005] Low degree of automation: Most of the existing devices rely on manual operation, requiring manual insertion and removal of a standard platinum resistance thermometer, manually adjusting the temperature of the constant temperature bath, and recording data. This operation method is not only cumbersome and error-prone, but also increases the risk of damage to the standard platinum resistance thermometer.

[0006] High cost: In order to improve the verification efficiency, some metrology verification units have adopted imported high-precision verification devices, but these devices are expensive, and the import price is usually about 2 million yuan, resulting in too high verification costs and restricting their wide application in China.

[0007] Supply-demand contradiction: Due to the increasing demand for heat meter verification and the low efficiency of the existing verification devices, the supply-demand contradiction of heat meter verification devices has become increasingly acute. For example, the verification device of the Hebei Institute of Metrology can only verify about 10 heat meters per day under normal circumstances, while the actual demand should be more than 30 units to meet the social needs.

[0008] In summary, the existing verification devices for heat meter temperature sensors have obvious deficiencies in terms of volume, efficiency, automation level, cost, etc., and cannot meet the current requirements for heat meter production and metrological verification. Therefore, it is of great significance to develop a high-efficiency, intelligent and compact heat meter temperature difference detection device. Summary of the Invention

[0009] The object of the present invention is to provide a constant temperature bath and a constant temperature method to solve the problems of large volume, low operating efficiency, low automation level and uneven temperature control in the existing verification device for heat meter temperature sensors.

[0010] To achieve the above object, the following technical solutions are adopted.

[0011] A constant temperature bath includes at least one temperature bath unit. The temperature bath unit includes a tank body, a magnetic stirrer rotatably arranged at the bottom inside the tank body, a cooling fan arranged at the bottom outside the tank body, a magnet arranged on the cooling fan and rotating with the cooling fan, a semiconductor refrigeration sheet wrapping the outer periphery of the tank body and the cooling fan, and a heat sink attached to the semiconductor refrigeration sheet.

[0012] Optionally, there are two temperature bath units, and the two temperature bath units are switched through a transmission mechanism for temperature switching.

[0013] Optionally, there are four temperature bath units, one of the temperature bath units is fixedly arranged, and the other three temperature bath units are switched through a transmission mechanism to set different temperatures for each temperature bath unit according to a temperature gradient.

[0014] Optionally, it further includes a control module, which is electrically connected to the semiconductor refrigeration sheet, the transmission mechanism and the cooling fan, and is used to control the temperature of the liquid in each temperature bath unit.

[0015] Optionally, the transmission mechanism includes a turntable arranged at the bottom of the switchable temperature bath unit, a power module for driving the turntable to rotate, and a bracket arranged on the turntable for supporting the switchable temperature bath unit.

[0016] Optionally, the semiconductor refrigeration sheet includes a plurality of semiconductor refrigeration units, which are arranged in a circular array along the outer periphery of the tank body. An elastic heat conduction layer is arranged between the cold end of each semiconductor refrigeration unit and the outer wall of the tank body, and the hot end is fixedly connected to the heat sink through a brazing layer.

[0017] Optionally, the magnet is an annular permanent magnet, with N-S magnetic poles alternating in the circumferential direction, and the included angle between adjacent magnetic poles is 30°-60°; Three sets of sector-shaped magnetic pole blocks are embedded inside the magnetic stirrer, and the magnetic pole arrangement is mirror complementary to the magnet. The magnet is coaxially fixed to the rotating shaft of the cooling fan, and a non-magnetic conductive isolation sleeve is arranged between the rotating shaft and the magnet. Axial positioning grooves are provided on the inner wall of the non-magnetic conductive isolation sleeve and are in sliding fit with the keys on the rotating shaft. The outer surface of the magnet is coated with a heat-conducting insulating layer, and its hot end is connected to the heat sink through a heat pipe. A temperature melting fault layer is arranged at the bottom of the magnetic stirrer for automatically demagnetizing when the temperature exceeds the preset dangerous temperature.

[0018] Optionally, a plurality of magnetic stirrers are further arranged on the inner side wall of the tank body. An outer shell is arranged outside the switchable temperature tank unit, and a magnet array is arranged on the inner side wall of the outer shell for driving the magnetic stirrers on the side wall to rotate during the switching process of the temperature tank unit.

[0019] A constant temperature method includes the following steps. Input the target temperature of each temperature tank unit through the control module, and preheat the liquid in the temperature tank unit to be close to the target temperature to ensure the temperature uniformity in the initial state. The control module starts the semiconductor refrigeration sheet and the cooling fan according to the input target temperature. The semiconductor refrigeration sheet contacts the outer wall of the tank through the elastic heat-conducting layer to achieve rapid cooling or heating. The cooling fan drives the magnetic stirrer to rotate through the ring permanent magnet to promote liquid mixing. The magnetic stirrer starts to rotate driven by the cooling fan. The sector-shaped magnetic pole blocks inside the magnetic stirrer interact with the ring permanent magnet on the cooling fan to uniformly stir the liquid. The temperature sensor in the temperature tank unit monitors the liquid temperature in real time and feeds the data back to the control module. The control module adjusts the working state of the semiconductor refrigeration sheet according to the feedback data to quickly stabilize the temperature to the target value. When it is necessary to switch the temperature tank unit, the control module sends an instruction to the transmission mechanism, and the power module starts to drive the turntable to rotate to prepare for switching the temperature tank unit. The turntable rotates, and the switchable temperature tank unit is moved to the working position through the bracket. At the same time, the magnet array on the inner side wall of the outer shell interacts with the magnetic stirrers on the side wall of the temperature tank unit to drive the magnetic stirrers on the side wall to rotate, so that the liquid temperature remains uniform during the switching process. The control module monitors the temperature in the switched temperature tank unit and confirms whether the temperature is stable at the target value. If it is not stable, continue to adjust the working state of the semiconductor refrigeration sheet until the temperature is stable. After the temperature stabilizes, the control module enters the constant temperature holding mode. The thermoelectric cooler and the cooling fan are fine-tuned according to the real-time data of the temperature sensor to maintain the temperature stability in the temperature control unit and complete the constant temperature process.

[0020] Optionally, the following steps are further included. In the initial setting, the control module automatically adjusts the initial temperature of each temperature control unit according to the preset program to ensure that the temperature gradient between different temperature control units meets the calibration requirements. When the temperature adjustment is started, the control module dynamically adjusts the cooling or heating power of the thermoelectric cooler and the rotation speed of the cooling fan according to the difference between the initial temperature and the target temperature of the liquid for rapid temperature adjustment. During the magnetic stirring synchronization process, the control module dynamically adjusts the rotation speed of the cooling fan according to the viscosity and temperature change of the liquid to change the stirring speed of the magnetic stirrer to ensure uniform mixing of the liquid at different temperatures. In temperature monitoring and feedback, the control module adopts the PID control algorithm to accurately adjust the working state of the thermoelectric cooler according to the feedback data of the temperature sensor for fast and stable temperature control. When preparing for the temperature control unit switching, the control module preheats or precools the temperature control unit that is about to be switched to the working position to reduce the temperature stabilization time after switching. During the execution of the temperature control unit switching, the control module real-time monitors the switching position and speed of the temperature control unit. When confirming the temperature stability, the control module judges whether the temperature in the temperature control unit is within the preset stable range through the real-time data of the temperature sensor. If the temperature fluctuation exceeds the allowable value, it automatically adjusts the working state of the thermoelectric cooler until the temperature stabilizes. In the constant temperature holding mode, the control module automatically adjusts the cooling or heating power of the thermoelectric cooler and the rotation speed of the cooling fan according to the real-time data of the temperature sensor to keep the temperature in the temperature control unit stable for a long time. At the same time, the control module records the temperature data and generates a temperature control curve for subsequent analysis and calibration.

[0021] Compared with the prior art, the present invention has the following beneficial effects: Through the integrated design, the present invention integrates multiple temperature control units in one device, significantly reducing the volume and floor area of the device. Compared with the conventional device that requires multiple independent constant temperature baths, the constant temperature bath of the present invention is more compact and is especially suitable for laboratories and production workshops with limited space.

[0022] A semiconductor refrigeration chip is used to achieve rapid heating and cooling. Compared with traditional heating tubes and compression refrigeration methods, the semiconductor refrigeration chip has a faster response speed and a higher energy efficiency ratio. Combined with the efficient mixing function of the magnetic stirrer, the liquid in the temperature bath can quickly reach the target temperature, significantly reducing the calibration time of the temperature sensor of the heat meter and improving the calibration efficiency.

[0023] The magnetic stirrer drives the liquid to achieve uniform mixing through the cooling fan, reducing the local temperature difference and ensuring the temperature uniformity in the temperature bath. This design improves the calibration accuracy of the temperature sensor of the heat meter, making the measurement at different temperature points more accurate.

[0024] The control module is electrically connected to the semiconductor refrigeration chip, the transmission mechanism and the cooling fan, realizing the automation of temperature control and temperature bath switching. The operator can easily set the target temperature and switch the program through the control module, reducing the complexity and error rate of manual operation, and improving the usability and reliability of the equipment.

[0025] The rapid switching of the temperature bath unit is realized through the transmission mechanism, which can meet the calibration requirements of the temperature sensor of the heat meter at multiple different temperature points. This design not only improves the calibration efficiency, but also reduces the waiting time of the equipment, meeting the high-efficiency requirements of heat meter production and metrological verification.

[0026] The high-efficiency refrigeration and heating capabilities of the semiconductor refrigeration chip, combined with the optimized heat dissipation design, improve the energy utilization efficiency and reduce the energy consumption. Compared with traditional equipment, the constant temperature bath of the present invention is more energy-saving and environmentally friendly, meeting the green development trend of modern industry.

[0027] The equipment is equipped with safety protection devices such as temperature melting layers. When the temperature exceeds the preset dangerous temperature, the protection mechanism is automatically triggered to prevent equipment damage and operator injury. This design improves the safety and reliability of the equipment, ensuring long-term stable operation.

[0028] The control module adopts an advanced PID control algorithm, dynamically adjusting the working state of the semiconductor refrigeration chip according to the real-time temperature feedback data to ensure that the temperature in the temperature bath quickly stabilizes to the target value. This precise control method improves the stability and accuracy of temperature control, meeting the requirements of different liquid characteristics and temperature regulation.

[0029] The control module can record temperature data and generate a temperature control curve, facilitating subsequent analysis and calibration by the operator. This function not only improves the intelligent level of the equipment, but also provides detailed data support for the calibration of the heat meter, helping to further optimize the verification process. Description of the Drawings

[0030] Figure 1 It is a schematic diagram of the internal structure of the temperature bath unit according to Embodiment 1 of a constant temperature bath of the present invention.

[0031] Figure 2 It is an overall schematic diagram of the two-temperature tank unit switching according to Embodiment 2 of a constant temperature bath of the present invention.

[0032] Figure 3 It is an internal structural schematic diagram of the two-temperature tank unit switching according to Embodiment 2 of a constant temperature bath of the present invention.

[0033] Figure 4 It is an overall schematic diagram of the four-temperature tank unit switching according to Embodiment 3 of a constant temperature bath of the present invention.

[0034] Figure 5 It is an internal schematic diagram of the four-temperature tank unit switching according to Embodiment 3 of a constant temperature bath of the present invention.

[0035] Wherein: 1. Temperature tank unit; 11. Tank body; 12. Magnetic stirrer; 13. Cooling fan; 14. Magnet; 15. Thermoelectric cooler; 16. Heat sink; 2. Transmission mechanism; 21. Turntable; 22. Power module; 23. Bracket; 3. Outer shell. Detailed implementation manners

[0036] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0037] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms adopted by the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which the present application belongs. The terms used in the present invention are only for describing specific implementation manners, and are not intended to limit the exemplary embodiments according to the present invention.

[0038] Embodiment 1

[0039] As Figure 1 shown, the present invention relates to a constant temperature bath, the core of which is to achieve efficient and stable temperature control through an integrated design, and is particularly suitable for the calibration of the temperature sensor of a heat meter. The following are the implementation manners of this constant temperature bath: The tank body 11 is the main structural component of the constant temperature bath and is used to hold the liquid to be calibrated. The tank body 11 is made of a material with high thermal conductivity, such as aluminum alloy or stainless steel, to ensure that heat can be quickly transferred to the liquid. The tank body 11 is internally designed with a suitable volume to meet different calibration requirements. For example, the volume can be selected between 1 liter and 10 liters, specifically depending on the size of the temperature sensor of the heat meter and the amount of calibration liquid.

[0040] The magnetic stirrer 12 is arranged at the inner bottom of the tank body 11 and is used to stir the liquid in the tank body 11 to ensure the uniformity of the liquid temperature. The stirrer is made of a material with high magnetic permeability, such as neodymium iron boron permanent magnet material, and its shape can be circular, oval or other shapes suitable for stirring. The stirrer is driven by magnetic force and can rotate freely in the tank body 11, thereby driving the liquid to mix. The rotation speed of the stirrer can be adjusted according to the viscosity of the liquid and the required mixing effect, and the general rotation speed range is 50 to 300 revolutions per minute.

[0041] The cooling fan 13 is arranged at the outer bottom of the tank body 11 and is used to provide a cooling air flow to help with heat dissipation. The cooling fan 13 is driven by a high-efficiency DC motor and has the characteristics of low noise and high air volume. The blades of the fan are designed as multi-blade types to increase the air flow efficiency. The rotation speed of the cooling fan 13 can be adjusted according to the actual heat dissipation requirements, usually between 1000 and 3000 revolutions per minute, to ensure that the semiconductor refrigeration chip 15 and the tank body 11 maintain an appropriate temperature during operation.

[0042] The magnet 14 is arranged on the cooling fan 13 and rotates together with the cooling fan 13. The magnet 14 uses a ring-shaped permanent magnet, and the N-S magnetic poles are alternately distributed circumferentially, and the included angle between adjacent magnetic poles is 30° to 60°. This design enables the magnet 14 to generate a stable magnetic field during rotation, interact with the magnetic stirrer 12, and drive the stirrer to rotate. The outer surface of the magnet 14 is coated with a heat-conducting insulating layer to prevent magnetic field leakage and improve the heat dissipation efficiency. The heat-conducting insulating layer uses a high heat-conductivity insulating material, such as alumina ceramic, and its thickness can be adjusted according to actual requirements.

[0043] The semiconductor refrigeration chip 15 is wrapped around the outer periphery of the tank body 11 and the cooling fan 13 and is used to quickly adjust the temperature in the tank body 11. The semiconductor refrigeration chip 15 is composed of multiple semiconductor refrigeration units, and these units are arranged in a circular array along the outer periphery of the tank body 11. An elastic heat-conducting layer is arranged between the cold end of each semiconductor refrigeration unit and the outer wall of the tank body 11 to ensure good heat conduction effect. The elastic heat-conducting layer uses a high heat-conductivity flexible material, such as heat-conducting silicone, and its thickness can be adjusted according to actual requirements. The hot end of the semiconductor refrigeration chip 15 is fixedly connected to the heat sink 16 through a brazing layer to ensure that heat can be quickly transferred to the heat sink 16 and dissipated. The refrigeration or heating power of the semiconductor refrigeration chip 15 can be dynamically adjusted according to the temperature requirements of the liquid in the tank body 11 to achieve fast and stable temperature control.

[0044] The heat sink 16 is attached to the hot end of the thermoelectric cooler 15 to dissipate the heat generated during the refrigeration process. The heat sink 16 is made of a high thermal conductivity material, such as aluminum alloy or copper alloy, and its surface is designed with multiple heat dissipation fins to increase the heat dissipation area. The thickness and fin spacing of the heat sink 16 can be adjusted according to the actual heat dissipation requirements. The heat sink 16 is connected to the hot end of the magnet 14 through a heat pipe to further improve the heat dissipation efficiency. The heat pipe is made of a metal material with a high thermal conductivity, such as copper or aluminum, and its interior is filled with an efficient heat transfer medium, such as water or ethanol.

[0045] Through the above design, the constant temperature bath of the present invention can achieve fast and stable temperature control, while ensuring the uniformity of the liquid temperature. This design is particularly suitable for the multi-point calibration of the temperature sensor of the heat meter, and can significantly improve the verification efficiency and accuracy.

[0046] Embodiment 2

[0047] As Figure 2 and Figure 3 shown, as a preferred example, two thermostat units 1 are further designed, and the switching between the thermostat units 1 is realized through a transmission mechanism 2 to meet the calibration requirements at different temperature points.

[0048] The constant temperature bath may include two thermostat units 1, and each thermostat unit 1 has an independent temperature control ability. The structure of each thermostat unit 1 is the same as that described in claim 1, including a tank body 11, a magnetic stirrer 12, a cooling fan 13, a magnet 14, a thermoelectric cooler 15, and a heat sink 16. The two thermostat units 1 can be set with different target temperatures respectively to meet the calibration requirements of the heat meter temperature sensor at different temperature points.

[0049] The transmission mechanism 2 can be used to switch between the two thermostat units 1. The transmission mechanism 2 includes a turntable 21, and the center of the turntable 21 is connected to the bottom of the thermostat unit 1. The design of the turntable 21 enables the two thermostat units 1 to rotate around its center, thereby realizing the switching. The turntable 21 is made of a high-strength material to ensure its durability and stability during frequent switching.

[0050] The power module 22 provides power for the rotation of the turntable 21, and it includes a motor and a speed reducer. The motor adopts a high-precision stepping motor, which can accurately control the rotation angle and speed of the turntable 21. The speed reducer is used to reduce the rotation speed of the motor and increase the torque to ensure the smooth rotation of the turntable 21. The power module 22 is electrically connected to the control module, and the control module controls its start, stop, and rotation speed according to a preset program.

[0051] The bracket 23 is arranged on the turntable 21 and is used to support the switchable temperature bath unit 1. The design of the bracket 23 ensures that the temperature bath unit 1 remains stable during the switching process and can be accurately positioned to the working position. The bracket 23 is made of high-strength aluminum alloy material, having good supporting ability and anti-deformation ability.

[0052] The switching process of the temperature bath unit 1 is as follows: In the initial state, one temperature bath unit 1 is in the working position, and the other temperature bath unit 1 is in the standby state. The liquid temperature in the temperature bath unit 1 in the working position has been adjusted to the target temperature, and the magnetic stirrer 12 is stirring the liquid to ensure the uniformity of the temperature.

[0053] While the temperature bath unit 1 in the working position is being calibrated, the control module starts the temperature adjustment process of the temperature bath unit 1 in the standby state according to the preset program. The temperature bath unit 1 in the standby state adjusts its temperature through its semiconductor refrigeration chip 15 and heat dissipation fan 13, making its liquid temperature gradually approach the target temperature. This pre-adjustment process ensures that the temperature bath unit 1 in the standby state is in a state of constant temperature when it is switched to the working position, reducing the temperature stabilization time after switching.

[0054] When the temperature bath unit 1 in the working position completes the calibration task, the control module sends a switching instruction to the power module 22. The power module 22 starts the motor and drives the turntable 21 to rotate through the reducer.

[0055] When the turntable 21 rotates, the bracket 23 drives the temperature bath unit 1 in the standby state to move to the working position, and at the same time moves the original temperature bath unit 1 in the working position to the standby state. The rotation angle and speed of the turntable 21 are precisely controlled by the control module to ensure the smoothness and accuracy of the switching process.

[0056] After the switching is completed, the control module stops the power module 22, and the new temperature bath unit 1 enters the working position. At this time, the new temperature bath unit 1 in the working position has reached the target temperature through the pre-adjustment process, and the control module continues to monitor its temperature to ensure that it remains constant during the working process. At the same time, the control module starts to adjust the temperature of the new temperature bath unit 1 in the standby state to reach the next target temperature, preparing for the next switching.

[0057] The control module plays an important role during the switching process of the temperature bath unit 1: According to the preset program and the real-time feedback data of the temperature sensor, the control module dynamically adjusts the working state of the semiconductor refrigeration sheet 15 to ensure that the liquid temperature in each temperature bath unit 1 quickly stabilizes to the target value. According to the preset switching program, the control module controls the start, stop, and rotation speed of the power module 22 to achieve the automatic switching of the temperature bath unit 1. While calibrating the temperature bath unit 1 in the working position, the control module starts the temperature adjustment of the standby temperature bath unit 1, making its liquid temperature gradually approach the target temperature to form a temperature gradient. This pre-adjustment function significantly reduces the temperature stabilization time after switching and improves the calibration efficiency.

[0058] The control module records the temperature data and switching time of each temperature bath unit 1, generates a temperature control curve, and provides data support for subsequent calibration analysis.

[0059] Through the above design, the constant temperature bath of the present invention can achieve rapid and stable switching between two temperature bath units 1. At the same time, through the pre-adjustment function, it ensures that the standby temperature bath unit 1 is in a state of constant temperature when switched to the working position. This design not only improves the calibration efficiency but also reduces the floor area of the equipment, having important application value.

[0060] Embodiment 3

[0061] As Figure 4 and Figure 5 shown, as a specific example, four temperature bath units 1 are further designed, where one temperature bath unit 1 is fixedly arranged, and the other three temperature bath units 1 are switched through the transmission mechanism 2 for setting different temperatures for each temperature bath unit 1 according to the temperature gradient. The following is a detailed description of this embodiment: The constant temperature bath includes four temperature bath units 1, and each temperature bath unit 1 has an independent temperature control ability. The structure of each temperature bath unit 1 is the same as that described in claim 1, including a tank body 11, a magnetic stirrer 12, a cooling fan 13, a magnet 14, a semiconductor refrigeration sheet 15, and a heat sink 16. The four temperature bath units 1 can be set with different target temperatures respectively to meet the calibration requirements of the heat meter temperature sensor at different temperature points.

[0062] Fixed temperature bath unit 1: One of the temperature bath units 1 is fixedly arranged to provide a reference temperature point. This temperature bath unit 1 is usually set to room temperature or a certain fixed temperature as a reference point during the calibration process.

[0063] The other three temperature bath units 1 are switched through the transmission mechanism 2 for setting different temperatures according to the temperature gradient. These three temperature bath units 1 can be set to low, medium, and high temperature points as needed to meet the calibration requirements of the heat meter temperature sensor under different temperature conditions.

[0064] The transmission mechanism 2 can be used to switch between three switchable temperature bath units 1. The transmission mechanism 2 includes a turntable 21, and the center of the turntable 21 is connected to the bottom of the switchable temperature bath unit 1. The turntable 21 is designed such that the three temperature bath units 1 can rotate around its center, thereby achieving the switching. The turntable 21 is made of high-strength materials to ensure its durability and stability during frequent switching. The power module 22 provides power for the rotation of the turntable 21, and it includes a motor and a speed reducer. The motor is a high-precision stepper motor, which can accurately control the rotation angle and speed of the turntable 21. The speed reducer is used to reduce the speed of the motor and increase the torque to ensure the smooth rotation of the turntable 21. The power module 22 is electrically connected to the control module, and the control module controls its start, stop, and rotation speed according to a preset program. The bracket 23 is arranged on the turntable 21 and is used to support the switchable temperature bath unit 1. The design of the bracket 23 ensures that the temperature bath unit 1 remains stable during the switching process and can be accurately positioned to the working position. The bracket 23 is made of high-strength aluminum alloy material and has good supporting ability and anti-deformation ability.

[0065] The switching process of the temperature bath unit 1 is as follows: In the initial state, one switchable temperature bath unit 1 is in the working position, and the other two temperature bath units 1 are in the standby state. The liquid temperature in the temperature bath unit 1 in the working position has been adjusted to the target temperature, and the magnetic stirrer 12 is stirring the liquid to ensure the uniformity of the temperature.

[0066] While the temperature bath unit 1 in the working position is being calibrated, the control module starts the temperature adjustment process of the temperature bath unit 1 in the standby state according to the preset program. The temperature bath unit 1 in the standby state adjusts its temperature through its semiconductor refrigeration chip 15 and heat dissipation fan 13, so that its liquid temperature gradually approaches the target temperature. This pre-adjustment process ensures that the temperature bath unit 1 in the standby state is in a state of constant temperature when it is switched to the working position, reducing the temperature stabilization time after switching.

[0067] When the temperature bath unit 1 in the working position completes the calibration task, the control module sends a switching instruction to the power module 22. The power module 22 starts the motor and drives the turntable 21 to rotate through the speed reducer.

[0068] When the turntable 21 rotates, the bracket 23 drives the temperature bath unit 1 in the standby state to move to the working position, and at the same time moves the original temperature bath unit 1 in the working position to the standby state. The rotation angle and speed of the turntable 21 are accurately controlled by the control module to ensure the smoothness and accuracy of the switching process.

[0069] After the switching is completed, the control module stops the power module 22, and the new temperature bath unit 1 enters the working position. At this time, the temperature bath unit 1 at the new working position has reached the target temperature through the pre-adjustment process. The control module continues to monitor its temperature to ensure that it remains constant during the working process. At the same time, the control module starts to adjust the temperature of the new standby temperature bath unit 1 to reach the next target temperature, preparing for the next switching.

[0070] The control module plays an important role in the switching process of the temperature bath unit 1: According to the preset program and the real-time feedback data of the temperature sensor, the control module dynamically adjusts the working state of the thermoelectric cooler 15 to ensure that the liquid temperature in each temperature bath unit 1 quickly stabilizes to the target value.

[0071] According to the preset switching program, the control module controls the start, stop and rotation speed of the power module 22 to realize the automatic switching of the temperature bath unit 1.

[0072] While calibrating the temperature bath unit 1 in the working position, the control module starts to adjust the temperature of the standby temperature bath unit 1 to make its liquid temperature gradually approach the target temperature, forming a temperature gradient. This pre-adjustment function significantly reduces the temperature stabilization time after switching and improves the calibration efficiency.

[0073] The control module records the temperature data and switching time of each temperature bath unit 1, generates a temperature control curve, and provides data support for subsequent calibration analysis.

[0074] Through the above design, the constant temperature bath of the present invention can achieve fast and stable switching between four temperature bath units 1. At the same time, through the pre-adjustment function, it is ensured that the standby temperature bath unit 1 is in a state of constant temperature when it is switched to the working position. This design not only improves the calibration efficiency but also reduces the floor area of the equipment, having important application value.

[0075] Embodiment 4 As a specific example, the thermoelectric cooler 15 is composed of a plurality of thermoelectric cooling units, and these units are distributed in a circular array along the outer periphery of the tank body 11. This layout makes the refrigeration or heating effect more uniform and can quickly adjust the temperature of the liquid in the tank body 11. The number of thermoelectric cooling units can be adjusted according to the size of the tank body 11 and the temperature control requirements, usually between 6 and 12.

[0076] An elastic heat-conducting layer is provided between the cold end of each semiconductor refrigeration unit and the outer wall of the tank body 11. The elastic heat-conducting layer is made of a flexible material with a high heat conductivity, such as heat-conducting silica gel or heat-conducting rubber. This material not only has good heat-conducting performance but also can adapt to the slight deformation between the tank body 11 and the semiconductor refrigeration unit to ensure good thermal contact. The thickness of the elastic heat-conducting layer is generally between 0.5 and 2 millimeters, and the specific thickness can be adjusted according to actual requirements.

[0077] The hot end of the semiconductor refrigeration unit is fixedly connected to the heat sink 16 through a brazing layer. The brazing layer is made of a metal material with a high heat conductivity, such as copper or aluminum, and the hot end of the semiconductor refrigeration unit is firmly connected to the heat sink 16 through a brazing process. This connection method not only ensures that heat can be quickly transferred to the heat sink 16 but also improves the structural stability and reliability. The thickness of the brazing layer is generally between 0.1 and 0.5 millimeters, and the specific thickness can be adjusted according to actual requirements.

[0078] The semiconductor refrigeration unit operates based on the Peltier effect and realizes refrigeration or heating by changing the direction of the current. When an electric current passes through the semiconductor refrigeration unit, the cold end absorbs heat and the hot end releases heat. By controlling the magnitude and direction of the current through the control module, the refrigeration or heating power of the semiconductor refrigeration unit can be precisely controlled, thereby realizing the rapid heating and cooling of the liquid in the tank body 11.

[0079] The control module dynamically adjusts the working state of the semiconductor refrigeration unit according to the real-time feedback data of the temperature sensor. When the temperature of the liquid in the tank body 11 is lower than the target temperature, the control module increases the heating power of the refrigeration unit; when the temperature is higher than the target temperature, the control module increases the refrigeration power. This dynamic adjustment method ensures that the temperature can be quickly stabilized to the target value and maintained within the set range.

[0080] The heat sink 16 is made of a material with high thermal conductivity, such as aluminum alloy or copper alloy, and its surface is designed with a plurality of heat dissipation fins to increase the heat dissipation area. The heat sink 16 is connected to the hot end of the magnet 14 through a heat pipe to further improve the heat dissipation efficiency. The heat pipe is made of a metal material with a high heat conductivity, such as copper or aluminum, and its interior is filled with an efficient heat transfer medium, such as water or ethanol. The design of the heat sink 16 not only ensures that the hot end of the semiconductor refrigeration unit can dissipate heat quickly but also improves the energy efficiency ratio of the entire constant temperature bath.

[0081] Through the above design, the constant temperature bath of the present invention can achieve rapid and stable temperature control while ensuring the uniformity of temperature distribution. The annular array layout of the semiconductor refrigeration units, the optimized design of the elastic heat-conducting layer and the brazing layer significantly improve the refrigeration and heating efficiency, reduce energy consumption, and improve the reliability and service life of the equipment.

[0082] As a specific example, the magnet 14 adopts an annular permanent magnet design, with N-S magnetic poles distributed alternately along the circumference. This design can generate a uniform and stable magnetic field, which is suitable for driving the magnetic stirrer 12. The included angle between adjacent magnetic poles is 30° to 60°, and the specific angle can be adjusted according to the size of the stirrer and the stirring requirements. For example, for a smaller tank 11, the included angle between adjacent magnetic poles can be set to 30°; for a larger tank 11, the included angle can be set to 60°.

[0083] The annular permanent magnet is coaxially fixed on the rotating shaft of the cooling fan 13 to ensure that the magnet 14 rotates synchronously with the cooling fan 13. This design not only improves the stirring efficiency but also further reduces the temperature of the magnet 14 through the airflow of the cooling fan 13, extending its service life.

[0084] A non-magnetic isolation sleeve is provided between the rotating shaft and the magnet 14 to prevent the magnetic field of the magnet 14 from affecting the rotating shaft. The non-magnetic isolation sleeve is made of a material with high strength and low magnetic conductivity, such as polytetrafluoroethylene (PTFE) or special engineering plastics. Axial positioning grooves are provided on the inner wall of the isolation sleeve, which are slidably engaged with the keys on the rotating shaft to ensure the stability of the magnet 14 during rotation.

[0085] The outer surface of the magnet 14 is coated with a thermally conductive insulating layer for protecting the magnet 14 and improving the heat dissipation efficiency. The thermally conductive insulating layer is made of an insulating material with high thermal conductivity, such as thermally conductive silicone or alumina ceramic. Its thickness can be adjusted according to actual needs, usually between 0.5 and 2 millimeters. The hot end of the thermally conductive insulating layer is connected to the heat sink 16 through a heat pipe to further improve the heat dissipation efficiency.

[0086] Three sets of sector-shaped magnetic pole blocks are embedded inside the magnetic stirrer 12, and the magnetic pole arrangement is mirror complementary to the annular permanent magnet. This design enables the magnetic stirrer 12 to rotate efficiently under the action of the magnetic field, driving the liquid in the tank 11 to mix. The sector-shaped magnetic pole blocks are made of a material with high magnetic permeability, such as neodymium iron boron permanent magnet material, to ensure the stirring efficiency.

[0087] A temperature melting fault layer is provided at the bottom of the magnetic stirrer 12 for automatically demagnetizing when the temperature exceeds the preset dangerous temperature. The temperature melting fault layer is made of a thermosensitive material. When the temperature reaches the set threshold (such as 120°C), the magnetism of the material will rapidly weaken or disappear, thus protecting the safety of the equipment and operators. The design of the temperature melting fault layer not only improves the safety of the equipment but also reduces the risk of equipment damage caused by high temperature.

[0088] Principle of operation When the cooling fan 13 rotates, the annular permanent magnet rotates synchronously with the fan, generating a rotating magnetic field. The sector-shaped magnetic pole blocks inside the magnetic stirrer 12 are driven to rotate under the action of the magnetic field, thereby driving the liquid in the tank 11 to mix and ensuring the uniformity of the liquid temperature.

[0089] The heat-conducting insulating layer on the outer surface of the magnet 14 transfers heat to the heat sink 16 through a heat pipe, and the heat sink 16 further dissipates heat through the airflow of the cooling fan 13 to ensure that the magnet 14 and the magnetic stirrer 12 maintain an appropriate temperature during operation.

[0090] When the temperature of the liquid in the tank body 11 rises abnormally and reaches the set threshold of the temperature melting layer, the temperature melting layer is automatically demagnetized, and the rotation of the magnetic stirrer 12 stops, avoiding equipment damage or safety accidents caused by high temperature.

[0091] Through the above design, the constant temperature tank of the present invention can achieve efficient and stable liquid mixing while ensuring the safe operation of the equipment. The optimized design of the annular permanent magnet and the magnetic stirrer 12 significantly improves the stirring efficiency, reduces the local temperature difference, and improves the accuracy of temperature control.

[0092] As a preferred example, magnetic stirrers 12 and a magnet array are provided on the inner side wall of the inner side of the tank body 11 and the inner side wall of the outer shell 3 to improve the stirring efficiency and temperature uniformity.

[0093] A plurality of magnetic stirrers 12 are provided on the inner side wall of the tank body 11, and these stirrers are evenly distributed along the inner side wall of the tank body 11. Each magnetic stirrer 12 is made of a material with high magnetic permeability, such as neodymium iron boron permanent magnet material, to ensure that it can rotate efficiently under the action of a magnetic field. The shape of the stirrer can be fan-shaped or rectangular, and the specific shape is designed according to the size of the tank body 11 and the stirring requirements.

[0094] The magnetic stirrer 12 is fixed to the inner side wall of the tank body 11 through an elastic connecting piece to ensure that it can adapt to the fluctuation of the liquid during rotation. The elastic connecting piece is made of a flexible material, such as polyurethane or silica gel, which not only ensures the stability of the stirrer but also allows it to rotate freely in the liquid.

[0095] The magnetic stirrer 12 rotates under the action of a magnetic field, driving the liquid in the tank body 11 to mix. By optimizing the shape and layout of the stirrer, more efficient liquid mixing can be achieved, the local temperature difference can be reduced, and the temperature uniformity can be improved.

[0096] The switchable temperature tank unit 1 is externally provided with an outer shell 3, and a magnet array is provided on the inner side wall of the outer shell 3. The magnet array is composed of a plurality of annular permanent magnets and is evenly distributed along the inner side wall of the outer shell 3. Each annular permanent magnet has N-S magnetic poles alternately distributed in the circumferential direction, and the included angle between adjacent magnetic poles is 30° to 60°, and the specific angle is adjusted according to the stirring requirements.

[0097] The annular permanent magnet is fixed on the inner side wall of the outer shell 3 through a non-magnetic isolation sleeve to prevent the magnetic field from affecting the outer shell 3. The non-magnetic isolation sleeve is made of a material with high strength and low magnetic conductivity, such as polytetrafluoroethylene (PTFE) or special engineering plastics. The inner wall of the isolation sleeve is provided with an axial positioning groove, which is slidably matched with the key on the outer shell 3 to ensure the stability of the magnet 14 during rotation.

[0098] When the temperature control unit 1 is switched, the magnet array in the outer shell 3 interacts with the magnetic stirrer 12 on the side wall of the tank body 11, driving the stirrer to rotate. This design not only improves the stirring efficiency but also ensures the uniformity of the liquid temperature during the switching process of the temperature control unit 1.

[0099] Stirring mechanism during the switching process of the temperature control unit 1. When the temperature control unit 1 is switched through the transmission mechanism 2, the magnet array in the outer shell 3 generates a rotating magnetic field to drive the magnetic stirrer 12 on the side wall of the tank body 11 to rotate. This design ensures continuous mixing of the liquid during the switching process, reduces temperature fluctuations, and improves the stability of temperature control.

[0100] The control module dynamically adjusts the magnetic field strength and rotation speed of the magnet array according to the switching state of the temperature control unit 1 and the temperature data of the liquid. In this way, the rotation speed of the stirrer can be optimized according to actual needs to ensure the mixing effect of the liquid at different temperatures.

[0101] The temperature sensor in the temperature control unit 1 real-time monitors the liquid temperature and feeds the data back to the control module. The control module adjusts the working state of the semiconductor refrigeration sheet 15 according to the feedback data to ensure that the liquid temperature in the temperature control unit 1 quickly stabilizes to the target value. At the same time, the control module optimizes the rotation effect of the stirrer by adjusting the magnetic field strength of the magnet array, further improving the temperature uniformity.

[0102] Through the above design, the constant temperature bath of the present invention can achieve efficient and stable liquid mixing, while ensuring the uniformity of the liquid temperature during the switching process of the temperature control unit 1. The optimized design of the magnetic stirrer 12 on the inner side wall of the tank body 11 and the magnet array on the inner side wall of the outer shell 3 significantly improves the stirring efficiency, reduces the local temperature difference, and improves the accuracy of temperature control.

[0103] Embodiment 5 The constant temperature method of the present invention is based on the constant temperature bath described in any one of claims 1-8, and realizes efficient and stable temperature control and switching of the temperature control unit 1 through a series of steps. The following are the detailed implementation steps of this method: Initial temperature setting: The target temperature of each temperature bath unit 1 is input through the control module. The control module receives the target temperature value input by the operator and stores it in the system. According to the input target temperature, the control module starts the preheating process to preheat the liquid in the temperature bath unit 1 to near the target temperature. The preheating process ensures temperature uniformity in the initial state and reduces the time for subsequent temperature adjustment.

[0104] Temperature adjustment start: According to the input target temperature, the control module starts the thermoelectric cooler 15 and the cooling fan 13. The thermoelectric cooler 15 contacts the outer wall of the tank body 11 through the elastic heat-conducting layer to achieve rapid cooling or heating. The cooling fan 13 drives the magnetic stirrer 12 to rotate through the annular permanent magnet to promote liquid mixing. The thermoelectric cooler 15 dynamically adjusts the cooling or heating power according to the difference between the target temperature and the current temperature to quickly adjust the temperature of the liquid in the temperature bath unit 1. The rotation of the cooling fan 13 drives the magnetic stirrer 12 to rotate to ensure uniform mixing of the liquid and reduce the local temperature difference.

[0105] Magnetic stirrer 12 start: The rotation of the cooling fan 13 drives the annular permanent magnet to rotate. The magnetic field of the annular permanent magnet acts on the sector-shaped magnetic pole block inside the magnetic stirrer 12, causing the magnetic stirrer 12 to start rotating. The rotation of the magnetic stirrer 12 further promotes liquid mixing to ensure uniform temperature distribution in the temperature bath unit 1. The rotation speed of the magnetic stirrer 12 can be dynamically adjusted according to the viscosity of the liquid and the temperature adjustment requirements.

[0106] Temperature monitoring and feedback: The temperature sensor in the temperature bath unit 1 monitors the liquid temperature in real time and feeds the data back to the control module. The control module adjusts the working state of the thermoelectric cooler 15 according to the feedback data. The control module adopts the PID control algorithm to dynamically adjust the cooling or heating power of the thermoelectric cooler 15 according to the real-time data of the temperature sensor to ensure that the liquid temperature in the temperature bath unit 1 quickly stabilizes to the target value.

[0107] Temperature bath unit 1 switching preparation: When it is necessary to switch the temperature bath unit 1, the control module sends a switching instruction to the transmission mechanism 2. The power module 22 starts to drive the turntable 21 to rotate to prepare for switching the temperature bath unit 1. The power module 22 starts the motor according to the instruction of the control module and drives the turntable 21 to rotate through the reducer to prepare for the switching of the temperature bath unit 1.

[0108] Temperature bath unit 1 switching execution: The turntable 21 rotates to move the switchable temperature bath unit 1 to the working position through the bracket 23. At the same time, the magnet array on the inner side wall of the outer shell 3 interacts with the magnetic stirrer 12 on the side wall of the temperature bath unit 1 to drive the magnetic stirrer 12 on the side wall to rotate. The temperature bath unit 1 maintains the temperature uniformity of the liquid during the switching process. The magnetic field of the magnet array acts on the magnetic stirrer 12 on the side wall to ensure that the liquid continues to mix during the switching process and reduce the temperature fluctuation.

[0109] Temperature stability confirmation: The control module monitors the temperature in the temperature bath unit 1 after switching, and confirms whether the temperature is stable at the target value. If it is not stable, continue to adjust the working state of the thermoelectric cooler 15. The control module dynamically adjusts the cooling or heating power of the thermoelectric cooler 15 according to the real-time data of the temperature sensor until the liquid temperature in the temperature bath unit 1 is stable at the target value.

[0110] Constant temperature maintenance mode: After the temperature is stable, the control module enters the constant temperature maintenance mode. The thermoelectric cooler 15 and the cooling fan 13 are finely adjusted according to the real-time data of the temperature sensor to maintain the temperature stability in the temperature bath unit 1. The control module records the temperature data and generates a temperature control curve for subsequent analysis and calibration. The constant temperature maintenance mode ensures that the liquid temperature in the temperature bath unit 1 remains stable for a long time to complete the constant temperature process.

[0111] As a specific example, the steps of temperature control and the switching of the temperature bath unit 1 are further optimized to improve the accuracy and efficiency of temperature regulation.

[0112] 1. Initial setting: The control module automatically adjusts the initial temperature of each temperature bath unit 1 according to the preset program. The preset program sets the temperature gradient between different temperature bath units 1 according to the calibration requirements of the heat meter temperature sensor. The temperature gradient between different temperature bath units 1 meets the calibration requirements, ensuring that each temperature bath unit 1 is close to the target temperature in the initial state, reducing the time and energy consumption of subsequent temperature regulation.

[0113] 2. Temperature regulation start: The control module dynamically adjusts the cooling or heating power of the thermoelectric cooler 15 and the rotation speed of the cooling fan 13 according to the difference between the initial temperature and the target temperature of the liquid. The specific adjustment strategy is as follows: If the initial temperature is lower than the target temperature, increase the heating power of the thermoelectric cooler 15, and at the same time adjust the rotation speed of the cooling fan 13 to optimize the heat dissipation effect.

[0114] If the initial temperature is higher than the target temperature, increase the cooling power of the thermoelectric cooler 15, and at the same time adjust the rotation speed of the cooling fan 13 to enhance heat dissipation.

[0115] By dynamically adjusting the power of the thermoelectric cooler 15 and the rotation speed of the cooling fan 13, rapid temperature regulation is achieved, reducing the time for the temperature bath unit 1 to reach the target temperature.

[0116] 3. Magnetic stirring synchronization: The control module dynamically adjusts the rotation speed of the cooling fan 13 according to the viscosity and temperature change of the liquid, thereby changing the stirring speed of the magnetic stirrer 12. The specific adjustment strategy is as follows: When the liquid viscosity is relatively high, appropriately increase the rotation speed of the cooling fan 13 to increase the stirring speed of the stirring bar to ensure uniform mixing of the liquid.

[0117] When the liquid temperature is relatively high, appropriately reduce the rotation speed of the cooling fan 13 to avoid liquid splashing caused by excessive stirring.

[0118] By dynamically adjusting the stirring speed, ensure uniform mixing of the liquid at different temperatures, reduce the local temperature difference, and improve the uniformity of temperature control.

[0119] 4. Temperature Monitoring and Feedback: The control module adopts the PID control algorithm and precisely adjusts the working state of the semiconductor refrigeration sheet 15 according to the feedback data of the temperature sensor. The specific steps are as follows: The temperature sensor continuously monitors the liquid temperature in the temperature control unit 1 and feeds the data back to the control module.

[0120] The control module calculates the temperature deviation based on the feedback data and adjusts the refrigeration or heating power of the semiconductor refrigeration sheet 15 through the PID control algorithm.

[0121] Through the PID control algorithm, achieve fast and stable temperature control to ensure that the liquid temperature in the temperature control unit 1 quickly stabilizes to the target value.

[0122] 5. Temperature Control Unit Switching Preparation: The control module preheats or precools the temperature control unit 1 that is about to be switched to the working position in advance. The specific operations are as follows: If the target temperature of the temperature control unit 1 to be switched is higher than the current temperature, start the heating function of the semiconductor refrigeration sheet 15 in advance for preheating.

[0123] If the target temperature of the temperature control unit 1 to be switched is lower than the current temperature, start the refrigeration function of the semiconductor refrigeration sheet 15 in advance for precooling.

[0124] By preheating or precooling in advance, reduce the temperature stabilization time after the temperature control unit 1 is switched and improve the calibration efficiency.

[0125] 6. Temperature Control Unit Switching Execution: The control module continuously monitors the switching position and speed of the temperature control unit 1. The specific operations are as follows: The control module monitors the rotation angle and speed of the turntable 21 through the sensor to ensure a smooth and accurate switching process of the temperature control unit 1.

[0126] The control module dynamically adjusts the output power of the power module 22 according to the monitoring data to ensure precise control of the switching process.

[0127] By continuously monitoring and dynamically adjusting, ensure a smooth and accurate switching process of the temperature control unit 1 and reduce the temperature fluctuation during the switching process.

[0128] 7. Temperature stability confirmation: The control module determines whether the temperature in the temperature bath unit 1 is within the preset stable range based on the real-time data of the temperature sensor. The specific operations are as follows: If the temperature fluctuation exceeds the allowable value, the control module automatically adjusts the working state of the thermoelectric cooler 15 until the temperature is stable.

[0129] The control module records the temperature data and generates a temperature control curve for subsequent analysis and calibration.

[0130] Through real-time monitoring and automatic adjustment, ensure that the temperature in the temperature bath unit 1 is stable at the target value, improving the calibration accuracy.

[0131] 8. Constant temperature holding mode: After the temperature is stable, the control module enters the constant temperature holding mode. The specific operations are as follows: The thermoelectric cooler 15 and the cooling fan 13 are finely adjusted according to the real-time data of the temperature sensor to maintain the temperature stability in the temperature bath unit 1.

[0132] The control module records the temperature data and generates a temperature control curve for subsequent analysis and calibration.

[0133] Through the constant temperature holding mode, ensure that the liquid temperature in the temperature bath unit 1 remains stable for a long time to complete the constant temperature process.

[0134] Through the above steps, the constant temperature method of the present invention can achieve efficient and stable temperature control and the switching of the temperature bath unit 1, significantly improving the calibration efficiency and accuracy of the heat meter temperature sensor. Each step is realized by specific technical features, ensuring the feasibility and integrity of the method.

[0135] As is known by common technical knowledge, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and not exclusive. All changes within the scope of the present invention or equivalent to the present invention are encompassed by the present invention.

Claims

1. A constant temperature bath, characterized in that: The invention comprises at least one temperature tank unit (1), wherein the temperature tank unit (1) comprises a tank body (11), a magnetic stirring bar (12) rotatably arranged at the bottom of the tank body (11), a cooling fan (13) arranged at the bottom of the tank body (11), a magnet (14) arranged on the cooling fan (13) and rotating together with the cooling fan (13), a semiconductor cooling sheet (15) wrapped around the tank body (11) and the outer periphery of the cooling fan (13), and a heat sink (16) attached to the outside of the semiconductor cooling sheet (15).

2. A constant temperature bath according to claim 1, characterized in that: There are two temperature tank units (1), and the two temperature tank units (1) are switched via a transmission mechanism (2) to switch the temperature.

3. A thermostatic bath according to claim 1, characterized in that: There are four temperature tank units (1), one of which is fixedly arranged, and the other three temperature tank units (1) are switched via a transmission mechanism (2) for setting different temperatures of each temperature tank unit (1) according to a temperature gradient.

4. A thermostatic bath according to claim 2 or 3, characterized in that: It also includes a control module, which is electrically connected to the semiconductor refrigeration plate (15), the transmission mechanism (2) and the heat dissipation fan (13) and is used to control the temperature of the liquid in each of the temperature tank units (1).

5. A constant temperature bath according to claim 2 or 3, characterized in that: The transmission mechanism (2) comprises a turntable (21) arranged at the bottom of the switchable temperature tank unit (1), a power module (22) used to drive the turntable (21) to rotate, and a bracket (23) arranged on the turntable (21) for supporting the switchable temperature tank unit (1).

6. A thermostatic bath according to claim 1, characterized in that: The semiconductor refrigeration sheet (15) comprises a plurality of semiconductor refrigeration units, which are distributed in a ring array along the periphery of the trough body (11), an elastic heat-conducting layer is provided between the cold end of each semiconductor refrigeration unit and the outer wall of the trough body (11), and the hot end is fixedly connected to the heat sink (16) via a brazing layer.

7. A constant temperature bath according to claim 1, characterized in that: The magnet (14) is an annular permanent magnet, with NS poles alternately distributed in the circumferential direction, and the angle between adjacent poles is 30°-60°; Three groups of sector-shaped magnetic pole blocks are embedded in the magnetic stirrer (12), and the magnetic pole arrangement is complementary to that of the magnet (14) in a mirror image; The magnet (14) is coaxially fixed to the rotating shaft of the cooling fan (13), and a non-magnetic isolation sleeve is provided between the rotating shaft and the magnet (14); The inner wall of the non-magnetic isolation sleeve is provided with an axial positioning groove, which is slidably matched with the key on the rotating shaft; The outer surface of the magnet (14) is covered with a heat-conducting insulating layer, and the hot end thereof is connected to the heat sink (16) via a heat pipe; A temperature fuse is arranged at the bottom of the magnetic stirrer (12) for automatic demagnetization when the temperature exceeds a preset dangerous temperature.

8. A constant temperature bath according to claim 2 or 3, characterized in that: The inner side wall of the tank body (11) is also provided with a plurality of magnetic stirrers (12); the switchable temperature tank unit (1) is provided with an outer shell (3) on the outside; the inner side wall of the outer shell (3) is provided with a magnet array for driving the magnetic stirrers (12) on the side wall to rotate during the switching process of the temperature tank unit (1).

9. A constant temperature method, based on a constant temperature bath according to any one of claims 1 to 8, characterized in that: The following steps are included: The target temperature of each temperature tank unit (1) is input through the control module, and the liquid in the temperature tank unit (1) is preheated to a temperature close to the target temperature, thereby ensuring the temperature uniformity in the initial state; The control module starts the semiconductor refrigeration sheet (15) and the heat dissipation fan (13) according to the input target temperature. The semiconductor refrigeration sheet (15) contacts the outer wall of the tank body (11) through the elastic heat-conducting layer to achieve rapid cooling or heating. The heat dissipation fan (13) drives the magnetic stirring bar (12) to rotate through the annular permanent magnet to promote liquid mixing. The magnetic stirrer (12) starts to rotate under the drive of the cooling fan (13), and the fan-shaped magnetic pole block inside the magnetic stirrer (12) interacts with the annular permanent magnet on the cooling fan (13), so that the liquid is stirred evenly; The temperature sensor in the temperature tank unit (1) monitors the liquid temperature in real time and feeds back the data to the control module. The control module adjusts the working state of the semiconductor cooling plate (15) according to the feedback data so that the temperature is quickly stabilized to the target value. When it is necessary to switch the temperature tank unit (1), the control module sends a command to the transmission mechanism (2), and the power module (22) starts to drive the turntable (21) to rotate, preparing to switch the temperature tank unit (1); The turntable (21) rotates, and the switchable temperature bath unit (1) is moved to the working position through the bracket (23). At the same time, the magnetic array on the inner wall of the housing (3) interacts with the magnetic stirrer (12) on the side wall of the temperature bath unit (1), driving the magnetic stirrer (12) on the side wall to rotate, so that the liquid temperature remains uniform during the switching process; The control module monitors the temperature in the temperature tank unit (1) after switching to confirm whether the temperature is stable at the target value, and if not, continues to adjust the working state of the semiconductor cooling plate (15) until the temperature is stable; After the temperature is stabilized, the control module enters a constant temperature holding mode, and the semiconductor cooling plate (15) and the cooling fan (13) are fine-tuned according to the real-time data of the temperature sensor to maintain the temperature in the temperature tank unit (1) stable, thus completing the constant temperature process.

10. A constant temperature method according to claim 9, characterized in that: The following steps are also included: During the initial setting, the control module automatically adjusts the initial temperature of each temperature bath unit (1) according to a preset program to ensure that the temperature gradient between different temperature bath units (1) meets the calibration requirements; When the temperature adjustment is started, the control module dynamically adjusts the cooling or heating power of the semiconductor refrigeration sheet (15) and the rotation speed of the cooling fan (13) according to the difference between the initial temperature of the liquid and the target temperature, so as to perform rapid temperature adjustment; During the synchronous magnetic stirring process, the control module dynamically adjusts the rotation speed of the cooling fan (13) and changes the stirring speed of the magnetic stirring bar (12) according to the viscosity and temperature changes of the liquid, so as to ensure uniform mixing of the liquid at different temperatures; In temperature monitoring and feedback, the control module adopts PID control algorithm to accurately adjust the working state of the semiconductor cooling plate (15) according to the feedback data of the temperature sensor, so as to perform fast and stable temperature control; When preparing for the temperature tank switching, the control module preheats or precools the temperature tank unit (1) that is about to be switched to the working position in advance, so as to reduce the temperature stabilization time after the switching; During the temperature tank switching process, the control module monitors the switching position and speed of the temperature tank unit (1) in real time; When the temperature is confirmed to be stable, the control module determines whether the temperature in the temperature tank unit (1) is within a preset stable range through real-time data from the temperature sensor, and if the temperature fluctuation exceeds the allowable value, the working state of the semiconductor cooling plate (15) is automatically adjusted until the temperature is stable; In the constant temperature maintenance mode, the control module automatically adjusts the cooling or heating power of the semiconductor refrigeration plate (15) and the rotation speed of the cooling fan (13) according to the real-time data of the temperature sensor, so that the temperature in the temperature tank unit (1) remains stable for a long time. At the same time, the control module records the temperature data and generates a temperature control curve for subsequent analysis and calibration.

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