Split type automatic temperature control device, method and application

Abstract

The invention provides a split type automatic temperature control device and method and application, the core of the device is that a split type structural design is adopted, a liquid nitrogen auxiliary alcohol two-stage refrigeration technology and a water medium heating technology are integrated, a heat preservation tank device is combined for cooperative work, and high-precision temperature regulation and control of a large-size sample can be achieved; the heat preservation groove filled with the refrigerating or heating medium is fixed to the surface of the large-size service sample in situ, a rubber strip and sealing mud dual-sealing mode is adopted, liquid medium leakage is prevented, and the heat preservation stability of the large-size sample is effectively improved. The invention provides an effective and feasible method for the in-situ test of the fracture performance of the marine structural material in the extreme environment, long-time stable temperature regulation can be carried out in a wide temperature range from-100 DEG C to 90 DEG C, the temperature control precision reaches + / -2.0 DEG C, and a key technical support is provided for the reliability and safety evaluation of the material in the extreme environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of material testing, in particular to a split type automatic temperature control device, method and application. BACKGROUND

[0002] In the fracture performance testing of ship materials and large-scale simulation test pieces, especially in the extreme working conditions (such as low temperature conditions of-10℃ to-70℃ required for polar service or high temperature environmental conditions of 30℃ to 50℃ in the tropics) under the global marine environment, constructing a stable, uniform and precisely controllable temperature environment is a key prerequisite for obtaining reliable fracture performance parameters.

[0003] At present, the temperature environment testing method of ship materials mostly adopts an integral design, that is, the refrigeration / heating system and the sample heat preservation cavity are integrated in a single closed box, and the temperature control is realized through contact type cold / hot conduction. Such technology is generally suitable for the testing of conventional small-size samples and can meet the basic temperature control requirements in a limited space.

[0004] However, with the development of large-scale and high-reliability ship equipment, there is an increasingly urgent need for full-thickness, full-scale and wide-temperature-range fracture performance testing of large-size test pieces or simulation pieces of typical structures such as ship hull steels and welded joints in service. The existing temperature control technology has significant shortcomings when dealing with such large-size samples: Firstly, the temperature uniformity and stability are difficult to guarantee. Due to space limitations, the integral box structure is difficult to accommodate large-size samples. Even if the box volume is forcibly enlarged, the internal temperature cycle will produce significant temperature gradient and hysteresis effect due to the excessively large space scale, resulting in a temperature difference of different regions of the sample far exceeding the standard allowable range (usually required within ±2℃), which seriously affects the accuracy of the measurement of key parameters such as fracture toughness and crack propagation rate. Secondly, the refrigeration capacity and efficiency are seriously insufficient. Traditional compressor refrigeration has a sharp decline in efficiency in the low temperature range, and it is difficult to achieve rapid and uniform cooling of large-volume samples in a reasonable time. If liquid nitrogen is directly sprayed on the sample, although low temperature can be achieved, the violent phase change impact can easily induce local supercooling or brittle fracture on the surface of the sample, which destroys the effectiveness of the test, and precise constant temperature control cannot be achieved. The existing solutions often sacrifice the cooling rate or add complex insulation layers to alleviate the contradiction, but they cannot fundamentally solve the core demand of rapid, uniform and stable temperature control of large-size samples in deep low temperature environment. Thirdly, the system lacks flexibility. The fixed box structure requires the sample to be moved into the temperature control cavity, which is extremely inconvenient for large-size test pieces that have already installed sensors or connected loading devices, and cannot support in-situ temperature testing.

[0005] In addition, patent 202411062105.X discloses a temperature regulating device and method for establishing a gradient temperature field on the surface of a sample, as Figure 8As shown, the left end of the sample is located between the first and second heat preservation grooves, the right end of the sample is located between the third and fourth heat preservation grooves, the fourth heat preservation groove comprises a shell, the shell is provided with an ultralow-temperature groove, a low-temperature groove and a high-temperature groove arranged in sequence from top to bottom, the ultralow-temperature groove, the ultralow-temperature driving pump and the ultralow-temperature liquid storage tank are connected in sequence through pipelines to form a first circulation loop, the temperature of the sample surface can be controlled in situ, but the temperature stability is poor due to the use of liquid nitrogen for cooling, and the sealing performance of the heat preservation groove is poor, after reaching the target temperature, the sample temperature fluctuates within ±5℃ for 30 minutes, and the precision and reliability requirements of wide temperature range testing of large-size ship structural parts cannot be met.

[0006] In summary, there is an urgent need for a wide temperature range temperature control device suitable for large and medium-sized ship structural parts in service to build a stable, uniform and precise temperature environment. SUMMARY

[0007] The purpose of the present application is to provide a split type automatic temperature control device, method and application, the high and low temperature control device with split type design adopts liquid nitrogen assisted alcohol two-stage refrigeration and water medium heating technology, cooperates with the heat preservation groove device, combines the double sealing design of rubber strip + sealing mud, realizes the high precision temperature regulation of large size sample, and reaches the ±2.0℃ precise temperature control in the wide temperature range (-100℃~90℃).

[0008] In order to achieve the above purpose, the present application provides a split type automatic temperature control device for adjusting the temperature of a sample, comprising a heat preservation groove, a high and low temperature control device, a circulation pipeline system and a temperature control system. The heat preservation groove comprises two hollow groove bodies respectively fitted to the opposite two side surfaces of the sample, the sample is clamped to form a temperature control chamber which locally wraps and seals the sample, the edge of the hollow groove body is provided with a sealing structure, the sealing structure comprises a rubber sealing strip embedded in the edge and industrial sealing mud coated on the outside of the rubber sealing strip. The high and low temperature control device comprises an alcohol tank and a hot water tank, the alcohol tank is connected with a liquid nitrogen source, and the hot water tank is provided with a heating element. The circulation pipeline system comprises a pipeline for connecting the heat preservation groove and the high and low temperature control device, and the pipeline is provided with a pumping element for pumping liquid to the heat preservation groove. The temperature control system comprises a control panel, and the pumping element and the heating element are electrically connected with the control panel.

[0009] In the present application, the upper side of the alcohol tank is preferably provided with a liquid nitrogen port; the alcohol tank is preferably connected with a liquid nitrogen tank through the liquid nitrogen port; specifically, the upper end of the alcohol tank is provided with a top cover, the top cover is provided with a closable liquid nitrogen port; the liquid nitrogen flow valve is arranged on the side close to the liquid nitrogen tank of the liquid nitrogen port, and is used for adjusting the liquid nitrogen flow.

[0010] The boiling point of liquid nitrogen is about -196 DEG C, far below normal temperature, when liquid nitrogen contacts with air, it will evaporate into gas state rapidly, in this phase change process, liquid nitrogen absorbs heat from the surrounding environment and takes away the heat of the contacted object, thus the temperature of the object is reduced.

[0011] The application adopts liquid nitrogen-alcohol bipolar refrigeration principle, takes alcohol as intermediate medium and liquid nitrogen as strong refrigerant, liquid nitrogen is passed into alcohol tank through flow valve, liquid nitrogen evaporates into gas state rapidly after contacting with alcohol, absorbs a large amount of heat of alcohol, and the cooled alcohol is pumped to the heat preservation tank through pipeline, thus low temperature control in the temperature range of -100 DEG C is realized and local supercooling damage caused by direct contact of liquid nitrogen with sample is avoided.

[0012] Further, the sample thickness is ≤100 mm, the width is >1 m and the length is >1 m.

[0013] In order to establish temperature field on the surface of large-size sample, the heat preservation tank and the high and low temperature control device are designed separately in the application, the heat preservation tank is fixed on the sample surface, and in-situ temperature control of large-size sample can be realized without taking down the sample and putting it into the device.

[0014] Further, the outside of the heat preservation tank is provided with rigid support clamps, the rigid support clamps are clamped by bolts to press and fix the two tank bodies on the sample surface.

[0015] In the application, the rigid support clamps are preferably crossbars, the bolts are arranged on the four corners of the heat preservation tank respectively; the industrial sealing mud is preferably glass mud, which can solidify at low temperature without cracks.

[0016] After the rubber sealing strip is embedded in the edge of the tank body, the high elasticity of the rubber is utilized, the rubber strip is extruded to produce elastic deformation by the bolt pressing of the rigid clamp, the rubber strip is tightly attached to the butt side of the heat preservation tank and the sample surface to form the first sealing barrier; at the same time, the sealing mud is coated at the contact position of the heat preservation tank and the sample, and a dense second sealing layer is formed after solidification to prevent liquid medium from leaking; in addition, the sealing mud can adapt to the unevenness of the sample surface.

[0017] Further, the heat preservation tank is of sandwich structure, including stainless steel material and heat preservation material from outside to inside; the inlet of the heat preservation tank is higher than the outlet; the position height of the high and low temperature control device is lower than that of the heat preservation tank, and liquid backflow is realized by gravity.

[0018] In the application, the heat preservation material is preferably heat preservation cotton.

[0019] The present application fixes the heat preservation tank on the sample, the high and low temperature control device is placed on the ground, and the liquid backflow is realized by gravity; the outlet of the heat preservation tank is arranged on the lower side of the tank body, and is used for backflowing alcohol or hot water to the high and low temperature control device.

[0020] Further, the top of the alcohol tank and the hot water tank is provided with a cover plate, and the cover plate is provided with a closable adding opening.

[0021] Specifically, the cover plate is respectively provided with an alcohol adding opening and a water adding opening, which are respectively used for adding alcohol and water.

[0022] Further, the alcohol tank and the hot water tank are both provided with a stirring device.

[0023] The present application provides a stirring device in the alcohol tank and the hot water tank, so as to keep the liquid flowing and make the temperature uniform.

[0024] Further, the temperature sensor is uniformly distributed on the surface of the sample and is used for detecting the temperature of the sample.

[0025] Further, the heat preservation tank and the high and low temperature control device are also provided with an exhaust valve.

[0026] In the present application, a liquid nitrogen exhaust valve is preferably arranged on the alcohol tank, which is used for releasing the gas generated by the evaporation of liquid nitrogen.

[0027] The present application provides an exhaust valve, which can release the excessively high pressure or balance the negative pressure in real time, avoids the damage of the equipment due to abnormal pressure, and prolongs the service life of the device.

[0028] The present application also provides a split type automatic temperature control method, which is used for the split type automatic temperature control device in the above technical solution, and comprises the following steps. Step S1: heat preservation tank installation, two hollow tank bodies of the heat preservation tank are fixed and attached to the surface of the sample, and the tank bodies are sealed by rubber sealing strips embedded in the edges of the tank bodies and industrial sealing mud coated on the outside of the rubber sealing strips; Step S2: starting the high and low temperature control device, the position height of the high and low temperature control device is lower than that of the heat preservation tank; starting the heating element outside the hot water tank when heating; opening the liquid nitrogen flow valve outside the alcohol tank when cooling, so as to cool; Step S3: starting the cycle, after the liquid in the hot water tank or the alcohol tank reaches the set temperature, the pumping element of the circulating pipeline system 4 is started, and the liquid in the hot water tank or the alcohol tank is pumped into the heat preservation tank 1; Step S4: after the heat preservation is finished, the heat preservation tank is not removed, and the sample is directly tested.

[0029] The application also provides application of the split type automatic temperature control device or the split type automatic temperature control method.

[0030] In the application, the low temperature can reach-100 DEG C, and the high temperature can reach 90 DEG C.

[0031] Compared with the prior art, the split type automatic temperature control device, the method and the application have the following advantages: (1) The split type high and low temperature control device is innovatively designed, a liquid nitrogen-alcohol double-stage refrigeration mode is adopted, the cooling process is realized by means of liquid nitrogen assisting alcohol medium, the cooling rate of the large-size sample is significantly improved, and the consumption of liquid nitrogen is reduced; and the heating water medium is adopted to realize the heating process.

[0032] (2) The heat preservation tank and the split type high and low temperature control device are designed separately, the heat preservation tank can be directly fixed in situ on the surface of the large-size sample in service, the sample does not need to be disassembled, the heavy sample with the sensor and the loading equipment can be tested without disassembly, and the stress state and the authenticity of the sample can be maintained to the maximum extent; (3) The sealing structure of the rubber strip combined with the sealing mud is adopted on the side of the heat preservation tank, the sealing effect is excellent, and the leakage of the circulating medium in the tank can be effectively prevented; (4) Precise and stable temperature control can be realized in a wide temperature range of-100 DEG C to 90 DEG C, the temperature control precision in the high and low temperature range reaches ± 2.0 DEG C, and the temperature requirement of the large-size structure material fracture performance test is met. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a schematic diagram of the split type automatic temperature control device of the application; Figure 2 It is a three-dimensional schematic diagram of the heat preservation tank and the high and low temperature control device; Figure 3 It is a top view of the heat preservation tank and the high and low temperature control device; Figure 4 It is a side view of the heat preservation tank and the high and low temperature control device; Figure 5 It is a front view of the heat preservation tank and the high and low temperature control device; Figure 6 It is a schematic diagram of the device cooling of embodiment 1 of the application; Figure 7 It is a schematic diagram of the device heating of embodiment 2 of the application; Figure 8 It is the temperature adjusting device for establishing a gradient temperature field on the surface of a sample described in patent 202411062105.X.

[0034] Mark explanation: 1, holding tank; 2, high and low temperature control device; 3, sample; 4, circulating pipeline system; 5, temperature control system; 1-1, bolt; 1-2, exhaust valve; 2-1, alcohol tank; 2-11, magnetic pump; 2-12, alcohol outlet; 2-13, alcohol return port; 2-2, hot water tank; 2-21, high temperature pump; 2-22, hot water outlet; 2-23, hot water return port; 2-3, stirring device; 4-1, pipeline; 5-1, control panel; 5-2, anti-static pipeline. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application with reference to the accompanying drawings and embodiments. It should be understood that the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0036] It should be noted that all the terms for directionality and positionality in the present application, such as "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "inner", "outer", "top", "low", "tail end", "head end", "center", etc., are only used to explain the relative position relationship, connection condition, etc. between the components in a certain state, and are only for the convenience of describing the present application, and are not required to construct and operate the present application in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the description of "first", "second", etc. in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation", etc. should be understood broadly, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through intermediate medium; can be internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For ordinary skilled persons in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In this embodiment of the invention, an alcohol outlet (2-12) and an alcohol return port (2-13) are provided on the alcohol tank (2-1); a hot water outlet (2-22) and a hot water return port (2-23) are provided on the hot water tank (2-2); the pipeline is a three-way pipeline, including a return three-way pipeline and an inlet three-way pipeline; the alcohol tank (2-1) and the hot water tank (2-2) are connected to the heat preservation tank (1) through the three-way pipeline; During cooling, the alcohol return port (2-13) is connected to the pipeline; When the temperature rises, the hot water return port (2-23) is connected to the pipeline. Example

[0039] 1. Conduct fracture performance tests on 40mm thick marine steel plates at -100℃. Large-size specimens should be fabricated according to Table 1. Under the same temperature testing conditions, ensure a minimum of 3 specimens. The notch on the specimen should be located at the center of either the long or wide side of the specimen, with both ends aligned on the same axis without deviation, and the notch direction parallel to the rolling direction of the steel plate.

[0040] Table 1 Measured dimensions of the specimen

[0041] 2. The specimen is connected to the clamp of the tensile testing machine by welding, and five temperature measuring points are evenly distributed from top to bottom at the center line of the specimen surface for temperature testing. The temperature data is recorded through the temperature acquisition system. Insulation grooves are installed on both sides of the specimen, ensuring that the test grooves are completely in contact with the specimen during installation.

[0042] 3. Connect the test insulation bath and the alcohol tank in the high and low temperature control device through pipelines, such as... Figure 6 As shown, the alcohol in the alcohol tank is cooled to the target temperature using liquid nitrogen assistance. A magnetic pump then pumps the cryogenic alcohol medium from the alcohol pump outlet, which is introduced into two chambers located above the insulated tank via a three-way pipe. The cryogenic alcohol in the two chambers flows through the valves below the insulated tank and through the alcohol three-way pipe under gravity, eventually returning to the alcohol return port on the alcohol tank. This process repeats, forming a liquid circulation loop for target temperature control. After the target temperature is reached, the tank is kept at that temperature for at least 30 minutes.

[0043] 4. After the heat preservation is completed, the test specimen is loaded at a uniform rate until the specimen completely breaks, and the maximum load during the test is recorded. After the test is completed, the specimen is removed.

[0044] After reaching the target temperature, the sample temperature was recorded during the heat preservation process. The heat preservation times were 30 min, 45 min and 60 min respectively. Within 30 min, the sample surface temperature was uniform and had cooled to -99.5℃. Within 60 min, the temperature difference range was ±2℃. There was almost no liquid leakage in the heat preservation tank. Example

[0045] 1. Fracture performance tests were conducted on 40mm thick marine steel plates at a high temperature of 90℃. Large-size specimens were processed according to the dimensions in Table 2. Under the same temperature test conditions, a total of 3 specimens were ensured. The notch on the specimen was located at the center of one of the long or wide sides of the specimen, and the notches at both ends were kept on the same axis without deviation. The direction of the notch was parallel to the rolling direction of the steel plate.

[0046] Table 2 Measured dimensions of the specimens

[0047] 2. The specimen is connected to the clamps of the tensile testing machine by welding. Five temperature measuring points are evenly distributed from top to bottom along the center line of the specimen surface for temperature testing. The temperature data is recorded through a temperature acquisition system. Insulation grooves are installed on both sides of the specimen, ensuring that the test grooves are completely in contact with the specimen during installation.

[0048] 3. Connect the test insulation bath and the hot water bath in the high and low temperature control device through pipes, such as... Figure 7 As shown: The target temperature is achieved by heating water. A high-temperature pump pumps hot water from its outlet, which then flows through a three-way pipe to two chambers located above the insulation tank. The hot water in these chambers flows back through a valve below the insulation tank, returning to the hot water return pipe by gravity, and finally back to the hot water return port on the hot water tank. This cycle repeats, forming a liquid circulation loop for temperature control. Once the target temperature is reached, the system is kept at that temperature for at least 30 minutes.

[0049] 4. After the heat preservation is completed, the test specimen is loaded at a uniform rate until the specimen completely breaks, and the maximum load during the test is recorded. After the test is completed, the specimen is removed.

[0050] After reaching the target temperature, the sample temperature was recorded during the heat preservation process. The heat preservation times were 30 min, 45 min and 60 min respectively. After 30 min, the sample surface temperature was uniform and had reached 90℃. The temperature difference range within 60 min was ±2℃. There was almost no liquid leakage in the heat preservation tank.

[0051] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A split-type automatic temperature control device for adjusting the temperature of a sample (3), characterized in that, It includes an insulation tank (1), a high and low temperature control device (2), a circulation pipeline system (4), and a temperature control system (5); The heat preservation tank (1) includes two hollow tanks that are respectively attached to the opposite two sides of the sample (3), forming a temperature control chamber that partially wraps and seals the sample (3) by clamping the sample (3); the edge of the hollow tank is provided with a sealing structure; the sealing structure includes a rubber sealing strip embedded in the edge and industrial sealing mud coated on the outside of the rubber sealing strip. The high and low temperature control device (2) includes an alcohol tank (2-1) and a hot water tank (2-2); the alcohol tank (2-1) is connected to a liquid nitrogen source, and the hot water tank (2-2) is equipped with a heating element; The circulating pipeline system (4) includes a pipeline (4-1) for connecting the heat preservation tank (1) and the high and low temperature control device (2); the pipeline (4-1) is equipped with a pumping element for pumping liquid into the heat preservation tank (1); The temperature control system (5) includes a control panel (5-1), and the pumping element and the heating element are electrically connected to the control panel (5-1).

2. The split-type automatic temperature control device according to claim 1, characterized in that, The sample (3) has a thickness ≤ 100 mm, a width > 1 m, and a length > 1 m.

3. The split-type automatic temperature control device according to claim 2, characterized in that, The outside of the heat preservation tank (1) is provided with a rigid support clamp, which is clamped by bolts (1-1) to press and fix the two tanks onto the surface of the sample (3).

4. A split-type automatic temperature control device according to claim 1 or 2, characterized in that, The heat preservation tank (1) has a sandwich structure, including stainless steel material and heat preservation material from the outside to the inside; the inlet of the heat preservation tank (1) is set higher than the outlet; the high and low temperature control device (2) is positioned at a height lower than the heat preservation tank (1), and liquid reflux is achieved by gravity.

5. A split-type automatic temperature control device according to claim 2, characterized in that, The top of the alcohol tank (2-1) and the hot water tank (2-2) are provided with a cover plate, and the cover plate is provided with a closable filling port.

6. A split-type automatic temperature control device according to claim 5, characterized in that, Both the alcohol tank (2-1) and the hot water tank (2-2) are equipped with a stirring device (2-3).

7. A split-type automatic temperature control device according to claim 1, characterized in that, It also includes a temperature sensor; the temperature sensor is evenly distributed on the surface of the sample (3) and is used to detect the temperature of the sample.

8. A split-type automatic temperature control device according to claim 1, characterized in that, The heat preservation tank (1) and the high and low temperature control device (2) are also equipped with exhaust valves.

9. A split-type automatic temperature control method, used in the split-type automatic temperature control device according to any one of claims 1 to 8, characterized in that, Including the following steps: Step S1: Installation of the heat insulation tank (1): Fix the two hollow tanks of the heat insulation tank (1) to the surface of the sample (3), and seal the tank with rubber sealing strips embedded in the edge of the tank and industrial sealing mud coated on the outside of the rubber sealing strips. Step S2: Start the high and low temperature control device (2), the high and low temperature control device (2) is positioned at a height lower than the heat preservation tank (1); when heating up, start the heating element in the hot water tank (2-2); when cooling down, open the liquid nitrogen flow valve outside the alcohol tank (2-1) to assist in cooling down the alcohol; Step S3: Start the circulation. After the liquid in the hot water tank (2-2) or alcohol tank (2-1) reaches the set temperature, turn on the pumping element of the circulation pipeline system (4) to pump the hot water or alcohol into the heat preservation tank (1). Step S4: After the heat preservation is completed, do not remove the heat preservation tank (1), and directly test the sample (3).

10. The application of the split-type automatic temperature control device according to any one of claims 1 to 8 or the split-type automatic temperature control method according to claim 9, characterized in that, Used for high / low temperature fracture performance testing of large-scale structures and simulated test specimens of ships currently in service.

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