A CTD collector heat preservation device and control method in an extreme environment

Abstract

This invention relates to the field of polar detection technology, specifically to a heat preservation device and control method for a CTD (Conductivity, Tolerance, and Difference) data acquisition device in extreme environments. After completing the acquisition operation, the CTD data acquisition device is placed in the heat preservation device to prevent the internal water sample from freezing. The CTD data acquisition device includes multiple acquisition bottles fixed in an upper support and a CTD detection component fixed in a lower support. Each acquisition bottle includes a bottle body and a cap located at the end of the bottle body. The bottle body has a long cylindrical structure and is arranged vertically along the upper support. The heat preservation device includes two symmetrically arranged shells. The shells have a cylindrical structure and are consistent with the shape of the CTD data acquisition device. The shells are slidably supported on a base via sliding blocks.

Description

Technical Field

[0001] This invention relates to the field of polar detection technology, specifically to a heat preservation device and control method for a CTD data acquisition device under extreme environments. Background Technology

[0002] In polar marine scientific expeditions, especially during Antarctic winter operations, environmental conditions are extremely harsh. Temperatures remain consistently between -20°C and -60°C, and sea surface temperatures are near freezing. Under these conditions, CTD (Conductivity, Temperature, Depth) data collectors, used to acquire seawater temperature, salinity, and depth (CTD) profiles and water samples, experience rapid icing of their metal surfaces when raised to the deck after underwater operations, posing a risk of freezing to the remaining seawater samples inside. This freezing not only alters the original physicochemical properties such as salinity, distorting valuable marine environmental data, but also risks cracking the sealing components of the collection bottle or connecting pipes due to the expansion effect of ice, causing permanent damage to the equipment. Therefore, providing a stable and mild thermal insulation environment for the CTD collector after it leaves the water, preventing the internal water samples from freezing and ensuring the safety of the electronic sensor units, is a crucial technical aspect for ensuring the success of scientific expeditions and obtaining reliable data. A dedicated, high-efficiency thermal insulation device is urgently needed.

[0003] Currently, a common solution for insulation equipment is active heating using a fan-based heater. While this method can quickly raise the local ambient temperature, it has significant drawbacks in the specific application scenarios of Antarctica. First, the heat from the heater's outlet is concentrated, leading to obvious localized overheating. CTD (Conductivity to Die) data loggers, freshly retrieved from near-freezing seawater, have extremely low component temperatures. If they are instantly exposed to direct hot air, the temperature difference can drastically exceed 80°C. This severe thermal shock can easily cause accelerated aging and loss of elasticity in the non-metallic components of the data logger, or thermal stress cracks at the junctions of metal and plastic, compromising the structural integrity and sealing of the equipment. More seriously, the dry, hot air blown out by the heater, upon contacting even colder equipment surfaces, especially areas with gaps such as bottle caps and valve interfaces, causes the water vapor to rapidly condense into liquid water and then freeze. This not only fails to provide freeze protection but also forms ice in critical sealing areas, exacerbating the risk of freezing and damage. Therefore, a single, centralized fan-based heating mode presents a dual challenge of safety and effectiveness in meeting the insulation needs of Antarctic CTD equipment.

[0004] Furthermore, existing insulation strategies struggle to achieve a balanced, efficient, and safe heating process in terms of overall control. Many insulation devices lack precise monitoring of the internal temperature gradient, typically using only a single temperature measurement point, failing to comprehensively perceive the true temperature status of different critical parts of the equipment. Without accurate data feedback, heating control can only operate based on simple switching or fixed power, unable to dynamically adjust to compensate for differences in heat loss in different areas. As a result, the temperature field inside the insulation chamber is severely uneven; areas near the heat source may overheat, while areas far from the heat source or located in dead air zones heat up slowly and remain under threat of freezing. This uneven heating not only fails to guarantee overall antifreeze effectiveness but also induces the aforementioned thermal stress problems due to excessive local temperature differences. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a heat preservation device for a CTD (Conductivity, Tolerance, and Disposal) data acquisition unit in extreme environments. After completing its acquisition operation, the CTD data acquisition unit is placed within this heat preservation device to prevent the internal water sample from freezing. The CTD data acquisition unit includes multiple acquisition bottles fixed within an upper support and a CTD detection assembly fixed within a lower support. Each acquisition bottle includes a bottle body and a cap located at the end of the bottle body. The bottle body is a long cylindrical structure arranged vertically along the upper support. The heat preservation device includes two symmetrically arranged shells, each shell being a cylindrical structure and conforming to the shape of the CTD data acquisition unit. Each shell is slidably supported on a base via a sliding block. A rotating platform is provided on the base, and the CTD data acquisition unit is placed on the rotating platform via a lifting device. A column is also provided on the base, and an upper hinge and a lower hinge are provided on the column. The two shells are hinged to the column via the upper and lower hinges.

[0006] Furthermore, the upper and lower supports are frame structures, and the multiple collection bottles are arranged circumferentially along the upper support; the housing of the heat preservation device is equipped with a warm air device and a heating component, the warm air device generates heat by delivering warm air, and the heating component generates heat by thermal radiation; the warm air device and the heating component are located at different heights on the housing.

[0007] Furthermore, the height of the air outlet of the heating device on the housing corresponds to the middle of the collection bottle in the CTD collector; a first temperature sensor is provided at the middle of the collection bottle; the height of the heating component on the housing corresponds to the position of the bottle cap of the collection bottle in the CTD collector; a second temperature sensor is provided at the position of the bottle cap of the collection bottle; and a third temperature sensor is provided at the CTD detection component.

[0008] Furthermore, the air outlets of the warm air device are evenly distributed at the same height along the circumference of the housing; the heating assembly includes an extension and a heating element disposed at the end of the extension; the extension extends laterally toward the center of the CTD collector so that the heating element is close to the cap of the collection bottle.

[0009] Furthermore, the outer side of the housing is provided with multiple handles; the bottom of the housing is provided with multiple sliders, which are evenly distributed along the circumference of the slider; the sliders are provided with multiple balls, so that the slide of the housing is slidably supported on the base by the balls.

[0010] Furthermore, the housing of the insulation device includes a stainless steel layer made of stainless steel pipe; it also includes a composite board layer wrapped around the outside of the stainless steel layer, and the interior of the composite board layer is filled with insulation cotton and a flexible garment; the insulation cotton is glass fiber insulation cotton or polyurethane insulation cotton.

[0011] The control method for the CTD data acquisition device insulation device under extreme environments of the present invention, using the above-mentioned CTD data acquisition device insulation device, includes the following steps: Step a: System initialization, set target temperature The controller parameters are reset, the integral term is cleared, and the heating power of the heating component is initialized to [value missing]. Or a safe preheating value; Step b, in each sampling period The controller reads the values ​​of the first, second, and third temperature sensors at the current time t. ; Step c: Calculate the readings of the first temperature sensor, the second temperature sensor, and the third temperature sensor relative to the target temperature. deviation ; Calculate the average temperature of the three sensors at time t and the standard deviation of temperature values The deviation of the first temperature sensor is processed by a saturation function. Saturation processing is performed, and weighting coefficients are introduced based on the different thermal sensitivity and importance of the three sensor locations to calculate the overall deviation. ; Step d: Calculate the control quantity of the heating component power and update the integral term. Calculate the unconstrained power demand according to the control law formula. The final command power is obtained by applying upper and lower power limits. ; Step e, calculate the... The signal is converted into a corresponding control signal to drive the heating element of the heating component to work; the next control cycle is executed repeatedly until the heat preservation process ends.

[0012] Furthermore, the readings of the first temperature sensor, the second temperature sensor, and the third temperature sensor are related to the target temperature. deviation, , , ;in, , , These are the measured values ​​of the first, second, and third temperature sensors at time t, respectively. , , This represents the temperature deviation at the corresponding time.

[0013] Furthermore, the aforementioned overall deviation, ,in, Let be the weight coefficient, and satisfy... ; It is a saturation processing function for the deviation of the first temperature sensor. It provides negative feedback to suppress heating when the temperature is too high, while having a smaller impact when the temperature is not too high. Specifically, , in, The first temperature sensor allows for a safety margin exceeding the target temperature. It is a gain greater than 1.

[0014] Furthermore, the output power of the heating element of the heating assembly The following PI control law, combined with uniformity compensation, determines the outcome. , in, This is the proportional gain coefficient; This is the integral gain coefficient; This is the uniformity compensation gain coefficient.

[0015] The beneficial effects of this invention are that the CTD acquisition unit's insulation device integrates the coordinated operation of a warm air device and a heating component. The warm air device, with its suitability for low-temperature environments, sufficient heating power, good cold resistance, and stable output, can quickly raise the base temperature of the insulation space. Meanwhile, the independently controlled heating component achieves distributed and gentle supplementary heating through thermal radiation, directly targeting key areas where warm air is difficult to cover evenly or is unsuitable for direct blowing for precise temperature control. This not only significantly improves the temperature uniformity inside the casing, avoiding the risk of localized overheating, material thermal aging, or thermal stress cracking caused by concentrated warm air jets, but also achieves closed-loop intelligent control through feedback from multiple temperature sensors, ensuring that the entire CTD acquisition unit can slowly recover to the set value within a safe and balanced temperature field, greatly improving the reliability of protection and the lifespan of the equipment; secondly... The air outlet of the heating device is located at the height of the shell corresponding to the middle of the collection bottle. This area has a relatively closed structure with few gaps, which can efficiently receive hot air for heating and greatly reduce the risk of condensation and rapid freezing caused by hot air blowing directly on the bottle cap, interface, and other gaps. At the same time, the heating component positions the heating element in the area corresponding to the bottle cap through the extension, providing targeted heat energy in the form of radiant heat, further eliminating the freezing risk of this key sealing part. The overall structural design of this invention fully considers the convenience and efficiency of polar field operations. The two shells can be easily opened and closed around the CTD collector through a mechanism consisting of a slide, hinge, and column. Combined with the rotating platform at the bottom, this simplifies the workflow when placing, removing, or maintaining the CTD equipment, reducing the difficulty and time required for personnel to operate in frigid environments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the CTD acquisition device for extreme environments according to the present invention. Figure 2 This is a schematic diagram of the thermal insulation device of the present invention after it is closed; Figure 3 This is a schematic diagram of the CTD acquisition device of the present invention; Figure 4 This is a schematic diagram of the structure of the warm air device and heating component in the heat preservation device of the present invention; Figure 5 This is a schematic diagram of the bottom slide of the heat preservation device of the present invention; Figure 6 This is a schematic diagram showing the installation height of the warm air device and heating component of the present invention; Figure 7 This is a cross-sectional view of the housing of the heat preservation device of the present invention; Figure 8 This is a logic architecture diagram of the heat preservation device control system of the present invention; Figure 9This is a flowchart of the control method for the heat preservation device of the present invention; In the picture: CTD data acquisition device 1, upper bracket 11, lower bracket 12, data acquisition bottle 13, bottle body 131, bottle cap 132, CTD detection assembly 14; Insulation device 2, shell 20, stainless steel layer 201, composite board layer 202, warm air device 21, heating component 22, extension 221, heating element 222, slide 23, slider 231, ball 232, handle 24; Base 3; Rotating platform 4; Column 5, upper hinge seat 51, lower hinge seat 52. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 The present invention will now be described in detail with reference to the accompanying drawings. The present invention provides a heat preservation device for a CTD (Conductivity, Tolerance, and Difference) acquisition device under extreme environments. After completing the acquisition operation, the CTD acquisition device 1 is placed in the heat preservation device 2 to prevent the internal water sample from freezing. The CTD acquisition device 1 includes multiple acquisition bottles 13 fixed within an upper support 11, and a CTD detection assembly 14 fixed within a lower support 12. Each acquisition bottle 13 includes a bottle body 131 and a bottle cap 132 disposed at the end of the bottle body 131. The bottle body 131 has a long cylindrical structure and extends along the upper support... The vertical arrangement of 11; the heat preservation device 2 includes two symmetrically arranged shells 20, the shells 20 are cylindrical structures and have the same shape as the CTD collector 1; the shells 20 are slidably supported on the base 3 by a sliding seat 23; a rotating platform 4 is provided on the base 3, and the CTD collector 1 is placed on the rotating platform 4 by a hoist; a column 5 is also provided on the base 3, and an upper hinge seat 51 and a lower hinge seat 52 are provided on the column 5, and the two shells 20 are hinged to the column 5 by the upper hinge seat 51 and the lower hinge seat 52.

[0019] The upper support 11 and lower support 12 are frame structures, and the plurality of collection bottles 13 are arranged around the circumference of the upper support 11; the housing 20 of the heat preservation device 2 is provided with a warm air device 21 and a heating component 22, the warm air device 21 generates heat by delivering warm air, and the heating component 22 generates heat by thermal radiation; the warm air device 21 and the heating component 22 are located at different heights on the housing 20.

[0020] The heater in the heating device 21 suffers from uneven heating. Excessively high outlet temperatures can lead to localized overheating, material aging, or stress cracking due to alternating hot and cold temperatures. The concentrated blowing of warm air from the heating device 21 onto specific interfaces can easily cause overheating, aging, or thermal stress cracking of local components in the CTD (Content Tolerance Device), such as plastic parts, seals, and precision sensors. Furthermore, the CTD is exposed to high-temperature air immediately after being removed from near-freezing seawater, with a temperature difference potentially exceeding 80°C, posing a significant risk. By incorporating a heating component 22 and using thermal radiation to generate heat, distributed multi-location heating is achieved, improving the uneven heating within the casing 20 of the insulation device 2. The heating component 22 can utilize heating wires, heating blankets, or heating lamps, among other heating devices.

[0021] The height of the air outlet of the heating device 21 on the housing 20 corresponds to the middle of the body 131 of the collection bottle 13 in the CTD collector 1; a first temperature sensor is provided at the middle of the body 131 of the collection bottle 13; the height of the heating component 22 on the housing 20 corresponds to the position of the cap 132 of the collection bottle 13 in the CTD collector 1; a second temperature sensor is provided at the position of the cap 132 of the collection bottle 13; and a third temperature sensor is provided at the CTD detection component 14. The third temperature sensor is located at the bottom, that is, in the lower part of the housing 20 and away from the heating device 21 and the heating component 22.

[0022] The heating device 21 blows out dry hot air. In the cold Antarctic environment, the hot air may condense into water and freeze rapidly in the colder parts of the CTD, which will increase the risk of freezing, especially in places with gaps such as the cap 132 of the collection bottle 13. Therefore, by setting the height of the air outlet of the heating device 21 on the housing 20 to the middle of the bottle body 131 of the collection bottle 13 in the CTD collector 1, the middle of the bottle body 131 is the ideal air receiving position. There are few gaps in the equipment in this area, which reduces the risk of the cap 132 of the collection bottle 13 freezing. At the same time, the heating component 22 is set at the corresponding height of the cap 132 of the collection bottle 13 to generate heat by thermal radiation, which improves the uneven heating in the housing 20.

[0023] The air outlets of the heating device 21 are evenly distributed at the same height along the circumference of the housing 20; the heating assembly 22 includes an extension 221 and a heating element 222 disposed at the end of the extension 221; the extension 221 extends laterally toward the center of the CTD collector 1 so that the heating element 222 is close to the cap 132 of the collection bottle 13. In specific operation, the circumferential position of the CTD collector 1 is adjusted by the rotary table 4 on the base 3 so that the extension 221 of the heating assembly 22 can avoid the upper support 11 and lower support 12 of the CTD collector 1 and enter a position closer to the cap 132 of the collection bottle 13.

[0024] The outer side of the housing 20 is provided with multiple handles 24; the bottom slide 23 of the housing 20 is provided with multiple sliders 231, which are evenly distributed along the circumference of the slide 23; the sliders 231 are provided with multiple balls 232, so that the slide 23 of the housing 20 is slidably supported on the base 3 by the balls 232.

[0025] The housing 20 of the heat preservation device 2 includes a stainless steel layer 201 made of stainless steel pipe; it also includes a composite board layer 202 wrapped around the outside of the stainless steel layer 201, and the composite board layer 202 is filled with heat preservation cotton and flexible clothing; the heat preservation cotton is glass fiber heat preservation cotton or polyurethane heat preservation cotton.

[0026] Example 2 To achieve balanced temperature control inside the CTD acquisition unit's insulation device and prevent overheating risks caused by localized heating of the heating device 21, this invention proposes a heating component power control method based on multi-point temperature feedback. By using first, second, and third temperature sensors located at specific positions to monitor the temperature in real time and dynamically adjust the power output of the heating component 22, the internal temperature of the insulation device 2 tends to be uniform and stable near the set target value.

[0027] This invention provides a control method for a heat preservation device of a CTD acquisition unit under extreme environments, comprising the following steps: Step a: System initialization, set target temperature The controller parameters are reset, the integral term is cleared, and the heating power of the heating component 22 is initialized to [value missing]. Or a safe preheating value; Step b, in each sampling period The controller reads the values ​​of the first, second, and third temperature sensors at the current time t. ; Step c: Calculate the readings of the first temperature sensor, the second temperature sensor, and the third temperature sensor relative to the target temperature. deviation ; Calculate the average temperature of the three sensors at time t and the standard deviation of temperature values The deviation of the first temperature sensor is processed by a saturation function. Saturation processing is performed, and weighting coefficients are introduced based on the different thermal sensitivity and importance of the three sensor locations to calculate the overall deviation. ; Step d: Calculate the control quantity of the power of the heating component 22 and update the integral term. Calculate the unconstrained power demand according to the control law formula. The final command power is obtained by applying upper and lower power limits. ; Step e, calculate the... The signal is converted into a corresponding control signal to drive the heating element 222 of the heating component 22 to work; the next control cycle is executed in a loop until the heat preservation process ends.

[0028] The core objective of the control method for the heat preservation device is to achieve and maintain a uniform and suitable temperature environment inside the housing 20 of the heat preservation device 2. This is to prevent the water sample inside the CTD collector 1 from freezing, and to prevent its precision components from being damaged by local overheating or thermal stress.

[0029] Specifically, a closed-loop feedback control is adopted, using the temperature of the third temperature sensor (monitoring the coldest point) as a reference and the temperatures of the first and second temperature sensors (monitoring potential overheating points and critical freezing points) as coordination. The power of the heating element 222 of the heating assembly 22... The system will be dynamically adjusted based on the temperature deviation and uniformity of the three monitoring points.

[0030] The readings of the first, second, and third temperature sensors are compared with the target temperature. Deviation: ; ; ; in, , , These are the measured values ​​from the first, second, and third temperature sensors at time t, respectively. , , This represents the temperature deviation at the corresponding time. The set target temperature.

[0031] Calculate the standard deviation of the temperature values ​​from the first, second, and third temperature sensors. As an indicator of internal temperature uniformity, ,in, Let t be the average temperature at the three monitoring points.

[0032] Because the three locations have different thermal sensitivities and importance, a weighting coefficient is introduced to calculate the overall deviation. To ensure that the coldest point (at the CTD detection component) is given priority, the deviation of the third temperature sensor is given a higher weight. At the same time, considering that the heating component 22 mainly acts near the bottle cap (the second sensor area), its deviation directly affects the control output. The first sensor area is directly affected by the warm air, and its deviation is mainly used to prevent overheating.

[0033] Overall Deviation ,in, These are weighting coefficients, and they typically satisfy... The specific values ​​need to be determined through experiments. This is a saturation processing function for the first sensor deviation, which provides negative feedback to suppress heating when the temperature is too high, and has a smaller impact when the temperature is not too high. It can be defined as: , in, The first temperature sensor allows for a safety margin exceeding the target temperature. A gain greater than 1 is used to amplify the suppression effect when the temperature value of the first temperature sensor is too high.

[0034] The output power of the heating element 222 of the heating assembly 22 The following PI control law, combined with uniformity compensation, determines the outcome. , in, This is the proportional gain coefficient; This is the integral gain coefficient; This is the uniformity compensation gain coefficient, which is usually negative when the internal temperature is non-uniform. When the value is high, this will adjust the power output to improve uniformity.

[0035] The integral term is used to eliminate steady-state error, and the power output must be constrained within the physical range. ,in and These are the minimum and maximum allowable power for heating element 222, respectively.

[0036] Through the above control method, the system can respond to temperature changes in different areas within the insulation device 2 in real time, intelligently adjust the heating power, and suppress local overheating and promote the uniform distribution of the overall temperature field while ensuring that the temperature of the coldest point is raised, thereby achieving safe, balanced and efficient insulation control.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat preservation device for a CTD (Conductivity to Diode) data acquisition unit under extreme conditions, wherein the CTD data acquisition unit (1) is placed in the heat preservation device (2) after completing the acquisition operation to prevent the internal water sample from freezing, characterized in that: The CTD acquisition device (1) includes multiple acquisition bottles (13) fixed in the upper bracket (11) and a CTD detection component (14) fixed in the lower bracket (12). The collection bottle (13) includes a bottle body (131) and a bottle cap (132) disposed at the end of the bottle body (131). The bottle body (131) is a long cylindrical structure and is arranged vertically along the upper support (11). The heat preservation device (2) includes two symmetrically arranged shells (20), the shells (20) are cylindrical structures and have the same shape as the CTD collector (1); The housing (20) is slidably supported on the base (3) by a slide (23); A rotating platform (4) is provided on the base (3), and the CTD acquisition device (1) is placed on the rotating platform (4) by a hoist; The base (3) is also provided with a column (5), and the column (5) is provided with an upper hinge seat (51) and a lower hinge seat (52). The two housings (20) are hinged to the column (5) through the upper hinge seat (51) and the lower hinge seat (52).

2. The CTD acquisition device heat preservation device according to claim 1, characterized in that: The upper support (11) and lower support (12) are frame structures, and the plurality of collection bottles (13) are arranged along the circumference of the upper support (11); The heat preservation device (2) is provided with a warm air device (21) and a heating component (22) on its shell (20). The warm air device (21) generates heat by delivering warm air, and the heating component (22) generates heat by thermal radiation. The warm air device (21) and the heating component (22) are located at different heights on the housing (20).

3. The CTD acquisition device heat preservation device according to claim 2, characterized in that: The height of the air outlet position of the heating device (21) on the housing (20) corresponds to the middle of the bottle body (131) of the acquisition bottle (13) in the CTD acquisition device (1); A first temperature sensor is provided at the middle of the body (131) of the collection bottle (13); The heating component (22) is positioned at a height in the housing (20) corresponding to the position of the cap (132) of the acquisition bottle (13) in the CTD acquisition device (1); A second temperature sensor is provided at the position of the cap (132) of the collection bottle (13); A third temperature sensor is provided at the CTD detection component (14).

4. The CTD acquisition device heat preservation device according to claim 3, characterized in that: The air outlets of the heating device (21) are evenly distributed at the same height along the circumference of the housing (20); The heating assembly (22) includes an extension (221) and a heating element (222) disposed at the end of the extension (221). The extension (221) extends laterally toward the center of the CTD collector (1) so that the heating element (222) is close to the cap (132) of the collection bottle (13).

5. The CTD acquisition device heat preservation device according to any one of claims 1-4, characterized in that: The outer side of the housing (20) is provided with a plurality of handles (24). Multiple sliders (231) are provided on the slide block (23) at the bottom of the housing (20), and the sliders (231) are evenly distributed along the circumference of the slide block (23); The slider (231) is provided with a plurality of balls (232), so that the slide (23) of the housing (20) is slidably supported on the base (3) by the balls (232).

6. The CTD acquisition device heat preservation device according to any one of claims 1-4, characterized in that: The housing (20) of the heat preservation device (2) includes a stainless steel layer (201) made of stainless steel pipe. It also includes a composite plate layer (202) wrapped around the outside of the stainless steel layer (201), and the composite plate layer (202) is filled with thermal insulation cotton and flexible clothing; The insulation material is either glass fiber insulation material or polyurethane insulation material.

7. A control method for a CTD (Conductor Tolerance Device) collector insulation device under extreme environments, employing the CTD collector insulation device described in any one of claims 1-6, characterized in that, Includes the following steps: Step a: System initialization, set target temperature The controller parameters are reset, the integral term is cleared, and the heating power of the heating component (22) is initialized to [value]. Or a safe preheating value; Step b, in each sampling period The controller reads the values ​​of the first, second, and third temperature sensors at the current time t. ; Step c: Calculate the readings of the first temperature sensor, the second temperature sensor, and the third temperature sensor relative to the target temperature. deviation ; Calculate the average temperature of the three sensors at time t and the standard deviation of temperature values The deviation of the first temperature sensor is processed by a saturation function. Saturation processing is performed, and weighting coefficients are introduced based on the different thermal sensitivity and importance of the three sensor locations to calculate the overall deviation. ; Step d: Calculate the control quantity of the power of the heating component (22) and update the integral term. Calculate the unconstrained power demand according to the control law formula. The final command power is obtained by applying upper and lower power limits. ; Step e, calculate the... The signal is converted into a corresponding control signal to drive the heating element (222) of the heating component (22) to work; the next control cycle is executed in a loop until the heat preservation process ends.

8. The control method according to claim 7, characterized in that: The readings of the first, second, and third temperature sensors are compared with the target temperature. deviation, , , ; in, , , These are the measured values ​​of the first, second, and third temperature sensors at time t, respectively. , , This represents the temperature deviation at the corresponding time.

9. The control method according to claim 8, characterized in that: The comprehensive deviation ,in, Let be the weight coefficient, and satisfy... ; It is a saturation processing function for the deviation of the first temperature sensor. It provides negative feedback to suppress heating when the temperature is too high, while having a smaller impact when the temperature is not too high. Specifically, ， in, The first temperature sensor allows for a safety margin exceeding the target temperature. It is a gain greater than 1.

10. The control method according to claim 9, characterized in that: The output power of the heating element (222) of the heating assembly (22) The following PI control law, combined with uniformity compensation, determines the outcome. ， in, This is the proportional gain coefficient; This is the integral gain coefficient; This is the uniformity compensation gain coefficient.

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