Underground PCB refrigerating device based on TEC semiconductor refrigerating technology

Abstract

The invention relates to the technical field of cooling heat exchange, and provides an underground PCB refrigeration device based on the TEC semiconductor refrigeration technology, the underground PCB refrigeration device comprises a drill collar and a first cover plate, the drill collar is provided with a containing groove used for containing a PCB refrigeration module, the PCB refrigeration module comprises a shell, a cold guide plate, a PCB and a plurality of semiconductor refrigeration pieces, the shell is provided with an oil cavity, and the oil cavity is provided with an oil outlet. The cold guide plate covers an opening of the oil cavity and abuts against the shell, the PCB is located in the oil cavity and connected with the inner wall of the cold guide plate, the cold ends of the multiple semiconductor chilling plates are all connected with the cold guide plate, the hot ends of the multiple semiconductor chilling plates all abut against the first cover, the oil cavity is filled with cooling liquid, and the cooling liquid is connected with the PCB. According to the cooling device, the whole circuit cooling of the whole space where the PCB is placed can be achieved through the combination of the semiconductor refrigeration technology and the cooling liquid, cooling is uniform, the refrigeration effect is good, and the cooling device has high sealing performance, can adapt to underground work and does not affect the refrigeration effect.

Description

Technical Field

[0001] The present invention relates to the field of cooling and heat exchange technology, and in particular to an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology. Background Art

[0002] At present, in the process of oil extraction, the downhole environment is extremely complex. The downhole temperature will increase with the increase of the well depth. In deep oil wells, the downhole temperature can be as high as 200°C. Therefore, the temperature of the drilling fluid outside the drill string and flowing through the water holes of the drill string in deep wells is very high, which causes the temperature of the PCB board in the drill string to rise. The PCB board in the drill string is a key component of the downhole measurement and control equipment. There are electronic components such as sensors and electronic chips on the PCB board. The high temperature environment will have a serious impact on the circuit components on the PCB board, causing the performance of the electronic components to decline, resulting in an increase in the sensor measurement error. In addition, the life of the electronic components will be reduced and prone to failure, which will seriously affect the safety and efficiency of the drilling operation.

[0003] Most of the solutions to the high temperature of PCB boards in underground drill strings are to make the electronic components themselves resistant to high temperatures, that is, passive temperature resistance, but this solution has limited high temperature resistance and high cost. There are also related underground active cooling systems that use semiconductor refrigeration sheets, but they have complex structures and uneven cooling of underground circuits, which can only ensure that some electronic components of the underground circuits are cooled, resulting in poor cooling effect and slow cooling efficiency for underground PCB boards.

[0004] The Chinese invention patent with patent number CN202110142811.5 proposes a TEC-based electromechanical integrated gas-liquid cooling device, including an air-cooled heat exchanger, a refrigeration component and a power supply; the air-cooled heat exchanger is provided with a refrigeration component on both sides of the circumference of the air-cooled heat exchanger, and the refrigeration component is connected to the power supply; the refrigeration component includes a PCB circuit board and a heat dissipation cold plate, the PCB circuit board corresponds to the side of the circumference of the air-cooled heat exchanger, and a plurality of TEC refrigerators are arranged on the PCB circuit board, the PCB circuit board is connected to the power supply, and the heat dissipation cold plate is parallel to the PCB circuit board and covers the side of the PCB circuit board away from the air-cooled heat exchanger; the air-cooled heat exchanger is close to the PCB circuit board The side corresponding to the position of the TEC refrigerator and the side of the heat dissipation cold plate close to the PCB circuit board The side corresponding to the position of the TEC refrigerator is respectively provided with thermal conductive silicone grease. The advantage is that it can not only provide a standard operating temperature for the scientific experiment load, but also meet the requirements of different scientific experiment loads by changing the current.

[0005] Although the above technology uses TEC refrigeration technology to cool the PCB board, this technology is applied in aerospace technology, and uses a combination of air-cooled heat exchangers and TEC semiconductor refrigeration technology to achieve cooling of the PCB board. It belongs to air heat exchange technology, and therefore the device is not airtight. In the oil production environment, the temperature can reach 200°C during underground mining, and the air is thin. There are waste liquids such as drilling fluid and fracturing return fluid, and heat cannot be dissipated through air heat exchange. In order to protect the PCB board and various electronic components, the heat dissipation device needs to be sealed. Therefore, this technology is not suitable for underground mining and has certain disadvantages. Summary of the invention

[0006] The purpose of the present invention is to provide an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology, which can achieve overall circuit cooling in the entire space where the PCB board is placed by combining semiconductor refrigeration technology with coolant, and has a good refrigeration effect with uniform cooling. The device has high sealing performance, can adapt to underground work and does not affect the refrigeration effect.

[0007] In order to solve the above technical problems, the technical solution adopted in this application is: The embodiment of the present application provides a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology, which includes a drill string body, the drill string body includes a drill collar and a first cover plate, a receiving groove for accommodating a PCB board refrigeration module is opened on the drill collar, the first cover plate cover is arranged at the mouth of the receiving groove, the first cover plate is connected to the drill collar, the PCB board refrigeration module includes a shell, a cold conduction plate, a PCB board and a plurality of semiconductor refrigeration sheets, the shell is provided with an oil cavity, the cold conduction plate cover is arranged at the mouth of the oil cavity and abuts against the shell, the PCB board is located in the oil cavity and connected to the inner wall of the cold conduction plate, the cold ends of the plurality of semiconductor refrigeration sheets are all connected to the cold conduction plate, the hot ends of the plurality of semiconductor refrigeration sheets are all abutted against the first cover body, the oil cavity is filled with coolant, and the PCB board refrigeration module is provided with a housing, a ... The CB board refrigeration module is placed therein and sealed by the first cover body, which can achieve an overall sealing effect. Therefore, the oil cavity can be filled with coolant, and the PCB board and the space can be cooled by TEC semiconductor refrigeration technology. The coolant can transmit the cooling effect to the entire oil cavity to achieve uniform cooling of the PCB board. Since the TEC semiconductor refrigeration sheet is smaller than the PCB board, the provided cold conduction plate can evenly transmit the cooling effect of multiple semiconductor refrigeration sheets to the PCB board to avoid uneven cooling. The device has a simple structure and adopts liquid heat exchange technology in a closed type. Compared with traditional refrigeration devices, it is more suitable for downhole operations. At the same time, during downhole drilling, the vibration and rotation can also enable the coolant to achieve better uniform heat dissipation effect.

[0008] In some embodiments of the present invention, the drill string body further includes a second cover plate, a battery compartment for accommodating batteries is provided on the drill collar, the second cover plate is covered at the mouth of the battery compartment, the second cover plate is connected to the drill collar, and the battery compartment and the PCB board cooling module are designed to be separated, which is convenient for replacing batteries while separating the batteries from the oil chamber, thereby increasing the service life of the batteries and facilitating maintenance and inspection by users.

[0009] In some embodiments of the present invention, the drill collar is further provided with a socket hole for accommodating an aviation socket, one end of the socket hole being connected to the battery compartment, and the other end being connected to the accommodating slot, the aviation socket being electrically connected to the battery, and the aviation socket being electrically connected to the PCB board and a plurality of semiconductor refrigeration sheets. The use of the aviation socket can make the power supply of the device highly reliable, the aviation socket is made of high-quality materials and high precision, the contact pieces are made of highly conductive metals, and the surfaces are subjected to special gold plating, silver plating and other treatments to reduce the heating phenomenon during signal transmission and the refrigeration pressure of the refrigeration module, and at the same time, the aviation socket has a long plug-in life, can increase the service life of the device, has waterproof and anti-corrosion functions, and meets the use requirements of the device, and at the same time, the drill string needs to work underground, and there will be a certain degree of vibration and impact, the aviation socket has high connection stability, and also has the functions of shock and impact prevention, which can prevent the connectors from falling off and increase the operating reliability of the device.

[0010] In some embodiments of the present invention, an aerogel felt is circumferentially arranged on the outer wall of the shell. The aerogel felt has a good heat insulation effect and its thermal conductivity is extremely low. The aerogel felt wrapped around the shell can effectively isolate the heat generated when the drill string is working, prevent the heat from being transmitted to the oil chamber, and reduce the refrigeration pressure. At the same time, the aerogel felt has low density, is light and thin, and has a small mass, which can reduce the load of the device. In addition, the aerogel felt also has good sealing properties, which makes it difficult for the coolant in the oil chamber to flow out, so that the device has high sealing properties. At the same time, it has good stability. In special working scenarios, such as underground work, long-term use will not cause aging, deformation and other problems, and the service life is long, reducing maintenance costs.

[0011] In some embodiments of the present invention, aerogel felt is filled between the first cover plate and the cold conduction plate, and a semiconductor refrigeration sheet is placed between the cold conduction plate and the first cover plate, so there is a gap between the two. The gap is filled with aerogel felt to make the device airtight. At the same time, the aerogel felt has a heat-insulating effect, so the semiconductor refrigeration sheet can completely transfer the cooling effect to the cold conduction plate. At the same time, the heat at the hot end is transferred to the outside of the device through the first cover plate, so that the device has good cooling and heat transfer effects, further reducing the temperature in the oil chamber.

[0012] In some embodiments of the present invention, the drill collar is provided with a first sealing groove for accommodating a first sealing ring. The first sealing groove is used to place the first sealing ring. The first sealing ring can increase the sealing performance of the connection between the drill collar and the first cover body after they are covered, thereby preventing impurities such as fracturing fluid or return fluid from entering the device during downhole operations and causing damage to the device.

[0013] In some embodiments of the present invention, the shell is provided with a second sealing groove for accommodating a second sealing ring. The second sealing groove is used to place the second sealing ring. The second sealing ring can increase the sealing between the cold guide plate and the shell, prevent the coolant in the oil chamber from flowing out, and increase the cooling effect.

[0014] In some embodiments of the present invention, the battery compartment is provided with a third sealing groove for accommodating a third sealing ring, which can increase the sealing of the shell and the second cover plate and prevent drilling fluid from entering the battery compartment and causing battery damage.

[0015] In some embodiments of the present invention, the drill collar is further provided with a wire outlet hole for accommodating electric wires, the wire outlet hole is connected to the accommodating groove, and the wire outlet hole is filled with sealant. Since the semiconductor refrigeration plate and the PCB board need to be electrically connected to the aviation socket, a wire outlet hole is provided, and the wire outlet hole is filled with sealant, which can make the oil cavity sealed and prevent the outflow of coolant.

[0016] In some embodiments of the present invention, the drill collar and the first cover plate are connected by a first cylindrical head screw, and the drill collar and the second cover plate are connected by a second cylindrical head screw. The first and second cylindrical head screws can withstand huge tensile force, compressive force and shear force, ensuring the stability of the device under various loads, while facilitating installation and disassembly, so that the first cover plate and the drill collar are tightly connected. When the drill string works underground, it is not easy to loosen or fall off due to vibration and impact, thereby reducing maintenance costs. In addition, the cylindrical head screws have high versatility and standardization, and are easy to replace. When in use, the preload force can be adjusted. Appropriate preload force can ensure the tightness and reliability of the connection and increase the service life of the bolt.

[0017] In some embodiments of the present invention, the shell and the cold conduction plate are fastened by cross slot countersunk screws, and a through hole is provided under the first cover plate. The shell and the cold conduction plate are fastened to form a whole, and then fastened to the first cover plate from bottom to top by cross slot countersunk screws. The semiconductor refrigeration plate is clamped between the first cover plate and the cold conduction plate to form a PCB board refrigeration module, and then the first cover plate in the PCB board refrigeration module is fastened to the drill collar by the first cylindrical head screw.

[0018] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: 1. The refrigeration module integrated based on semiconductor refrigeration technology is easy to assemble in the drill string and is easy to install.

[0019] 2. The combination of semiconductor refrigeration technology and coolant can achieve uniform cooling, so that the temperature of the PCB board and the surrounding space can be maintained at the required temperature.

[0020] 3. The aerogel felt can effectively isolate heat return and achieve long-term stable cooling.

[0021] 4. Powered by the integrated design of the battery compartment and aviation socket, the battery specification can be selected according to the required working time of the PCB board, which is portable and flexible.

[0022] 5. The device has high sealing performance and can adapt to the underground working environment. It can also withstand the vibration and impact generated during operation, reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 An exploded view of an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 2 A schematic diagram of the overall structure of an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 3 A side view of an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 4 AA cross-sectional view of an underground PCB board cooling device based on TEC semiconductor cooling technology provided in this embodiment Figure 1 ; Figure 5 The second AA cross-sectional view of a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 6 The third AA cross-sectional view of a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 7 A partial enlarged view of the D portion of an underground PCB board cooling device based on TEC semiconductor refrigeration technology provided in this embodiment; Figure 8 A partial enlarged view of point E of an underground PCB board cooling device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig. 9 A partial enlarged view of the F portion of an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig.10 A schematic diagram of the installation of a semiconductor cooling plate of a downhole PCB board cooling device based on TEC semiconductor cooling technology provided in this embodiment; Fig.11 An exploded view of a PCB board refrigeration module of an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig.12 The overall front view of a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig.13 A BB cross-sectional view of a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig.14 A CC cross-sectional view of a downhole PCB board cooling device based on TEC semiconductor refrigeration technology provided in this embodiment; Fig.15 A schematic diagram of a test system for an underground PCB board refrigeration device based on TEC semiconductor refrigeration technology provided in this embodiment.

[0025] Icons: 100-drill collar; 110-first sealing groove; 120-accommodating groove; 200-first cover plate; 210-first cylindrical head screw; 220-aerogel felt; 230-housing; 231-second sealing groove; 232-oil chamber; 233-cross recessed countersunk screw; 250-semiconductor refrigeration plate; 260-cold conduction plate; 270-PCB board; 280-wire outlet; 300-second cover plate; 310-second cylindrical head screw; 320-battery; 330-aviation socket; 340-socket hole; 350-battery compartment; 351-third sealing groove; 400-DC regulated power supply; 500-adjustable DC power supply; 600-temperature sensor; 700-test device; 800-constant temperature container; 900-thermal oil pump; 1000-data acquisition instrument; 1100-auxiliary heating device. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1 Please refer to Figure 1-14 , Figure 1 Shown is an exploded view of an embodiment of the present invention; Figure 2 Shown is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 3 Shown is a side view of an embodiment of the present invention; Figure 4 The AA cross-sectional view of an embodiment of the present invention is shown. Figure 1 ; Figure 5 The second AA cross-sectional view of the embodiment of the present invention is shown; Figure 6 The third AA cross-sectional view of the embodiment of the present invention is shown; Figure 7 The figure shows a partial enlarged view of the D part of the embodiment of the present invention; Figure 8 The figure shows a partial enlarged view of position E of an embodiment of the present invention; Fig. 9 The figure shows a partial enlarged view of the F part of the embodiment of the present invention; Fig.10 The figure shows a schematic diagram of installing a semiconductor cooling sheet 250 according to an embodiment of the present invention; Fig.11 The figure shows an exploded view of a PCB board cooling module according to an embodiment of the present invention; Fig.12 The figure shows an overall front view of the device according to an embodiment of the present invention; Fig.13 The BB cross-sectional view of an embodiment of the present invention is shown; Fig.14 Shown is a CC cross-sectional view of an embodiment of the present invention.

[0029] The present embodiment provides a downhole PCB board 270 refrigeration device based on TEC semiconductor refrigeration technology, which includes a drill string body, the drill string body includes a drill collar 100 and a first cover plate 200, the drill collar 100 is provided with a receiving groove 120 for accommodating a PCB board refrigeration module, the first cover plate 200 is covered at the mouth of the receiving groove 120, the first cover plate 200 is connected to the drill collar 100, the PCB board refrigeration module includes a shell 230, a cold conduction plate 260, a PCB board 270 and a plurality of semiconductor refrigeration sheets 250, the shell 230 is provided with an oil cavity 232, the cold conduction plate 260 is covered at the mouth of the oil cavity 232 and abuts against the shell 230, the PCB board 270 is located in the oil cavity 232 and is connected to the inner wall of the cold conduction plate 260, the cold ends of the plurality of semiconductor refrigeration sheets 250 are all connected to the cold conduction plate 260, the hot ends of the plurality of semiconductor refrigeration sheets 250 are all abutted against the first cover body, and the oil cavity 232 is filled with cooling liquid.

[0030] As attached Figure 1-9As shown, by opening a receiving groove 120 in the drill string, placing the PCB board refrigeration module therein, and sealing it with the first cover body, an overall sealing effect can be achieved. Therefore, the oil cavity 232 can be filled with coolant, and the PCB board 270 and the space can be cooled by TEC semiconductor refrigeration technology. The coolant can transmit the cooling effect to the entire oil cavity 232 to achieve uniform cooling of the PCB board 270. Since the TEC semiconductor refrigeration plate 250 is smaller than the PCB board 270, the provided cold plate 260 can evenly transmit the cooling effect of multiple semiconductor refrigeration plates 250 to the PCB board 270 to avoid uneven cooling. The device has a simple structure and adopts liquid heat exchange technology in a closed type. Compared with traditional refrigeration devices, it is more suitable for downhole operations. At the same time, during the downhole drilling process, the vibration and rotation of the coolant can also enable the coolant to achieve better uniform heat dissipation effect.

[0031] As attached Figure 1-9 As shown, in order to realize power supply of the device, the drill string body also includes a second cover plate 300, and a battery compartment 350 for accommodating a battery 320 is provided on the drill collar 100. The second cover plate 300 is covered at the mouth of the battery compartment 350, and the second cover plate 300 is connected to the drill collar 100. The battery compartment 350 and the PCB board cooling module adopt a separate design, which is convenient for replacing the battery 320, and also separates the battery 320 from the oil chamber 232, thereby increasing the service life of the battery 320 and facilitating maintenance and repair by users.

[0032] In order to increase the stability of the power supply part, the drill collar 100 is also provided with a socket hole 340 for accommodating an aviation socket 330. One end of the socket hole 340 is connected to the battery compartment 350, and the other end is connected to the accommodating groove 120. The aviation socket 330 is electrically connected to the battery 320. The aviation socket 330 is also electrically connected to the PCB board 270 and multiple semiconductor cooling sheets 250. The use of the aviation socket 330 can make the power supply of the device highly reliable. The aviation socket 330 is made of high-quality materials and high precision. The contact pieces are made of highly conductive metal, and the surface is specially gold-plated, silver-plated, etc. to reduce the heat generation during signal transmission and the cooling pressure of the cooling module. At the same time, the aviation socket 330 has a long plug-in life, which can increase the service life of the device. It has waterproof and anti-corrosion functions to meet the use requirements of the device. At the same time, the drill string needs to work underground, and there will be a certain degree of vibration and impact. The aviation socket 330 has high connection stability and also has the function of shockproof and impact-proof to prevent the connector from falling off and increase the operating reliability of the device.

[0033] As attached Figure 6-11As shown, the drill collar 100 is further provided with a wire outlet hole 280 for accommodating the wires, the wire outlet hole 280 is communicated with the accommodating groove 120, and the wire outlet hole 280 is filled with sealant. Since the semiconductor refrigeration plate and the PCB board 270 need to be electrically connected to the aviation socket 330, the wire outlet hole 280 is provided, and the wire outlet hole 280 is filled with sealant, which can make the oil chamber 232 airtight and prevent the coolant from flowing out.

[0034] In order to increase the stability of the connection between the drill collar 100 and the first cover body, the drill collar 100 and the first cover plate 200 are connected by a first cylindrical head screw 210, and the drill collar 100 and the second cover plate 300 are connected by a second cylindrical head screw 310. The first cylindrical head screw 210 and the second cylindrical head screw 310 can withstand huge tensile force, pressure and shear force, ensuring the stability of the device under various loads, and are easy to install and disassemble, so that the first cover plate 200 and the second cover plate 300 are tightly connected to the drill collar 100. When the drill string works underground, it is not easy to loosen or fall off due to vibration and impact, reducing maintenance costs. In addition, the cylindrical head screws have high versatility and standardization, and are easy to replace. When in use, the preload force can be adjusted. Appropriate preload force can ensure the tightness and reliability of the connection and increase the service life of the bolts.

[0035] In order to fix the PCB board cooling module, the above-mentioned shell 230 and the cold conduction plate 260 are fastened by cross slot countersunk screws 233, and a through hole is provided at the bottom of the first cover plate 200. The shell 230 and the cold conduction plate 260 are fastened to form a whole, and then fastened to the first cover plate 200 from bottom to top by cross slot countersunk screws 233, so that the semiconductor cooling plate 250 is clamped between the first cover plate 200 and the cold conduction plate 260 to form a PCB board cooling module, and then the first cover plate 200 and the drill collar 100 in the PCB board cooling module are fastened by the first cylindrical head screw 210.

[0036] When in use, a receiving groove 120 is opened for the part of the drill string where the PCB board 270 needs to be placed, and a battery compartment 350 is opened for the part where the battery 320 needs to be placed. A socket hole 340 for accommodating the aviation socket 330 is opened between the battery compartment 350 and the receiving groove 120. The shell 230 is placed in the receiving groove 120, and the oil cavity 232 in the shell 230 is filled with coolant. The PCB board 270 is welded to the inner wall of the cold conduction plate 260. After the PCB board 270 is placed in the oil cavity 232, the wires are led out through the outlet hole 280, and the outlet hole 280 is sealed with a sealant. The led-out wires are electrically connected to the aviation socket 330 by welding, and the cold conduction plate is fixed by bolts. 260 is connected to the shell body 230, and three semiconductor cooling plates 250 are evenly placed on the cold conduction plate 260. The semiconductor cooling plates 250 are also electrically connected to the aviation socket 330 after being welded with wires. The first cover body is fixedly connected to the drill collar 100 by the first cylindrical head screw 210. After the lithium battery 320 is placed in the battery compartment 350, the second cover body is fixedly connected to the drill collar 100 by the second cylindrical head screw 310. During the drilling process, when the PCB board 270 starts to work, the semiconductor cooling plates 250 start to cool and keep the temperature of the PCB board 270 below 175°C, and the heat generated is dissipated through the first cover plate 200 along with the drilling fluid outside the drill collar 100.

[0037] Example 2

[0038] Please refer to Figure 1-14 On the basis of Example 1, an aerogel felt 220 is circumferentially arranged on the outer wall of the shell 230. The aerogel felt 220 has a good heat insulation effect and its thermal conductivity is extremely low. The aerogel felt 220 wrapped around the shell 230 can well isolate the heat generated by the drill string when it is working, prevent the heat from being transmitted to the oil chamber 232, and reduce the refrigeration pressure. At the same time, the aerogel felt 220 has a low density, is light and thin, and has a small mass, which can reduce the load of the device. In addition, the aerogel felt 220 also has good sealing properties, so that the coolant in the oil chamber 232 is not easy to flow out, so that the device has high sealing properties. At the same time, it has good stability. In special working scenarios, such as underground work, long-term use will not cause aging, deformation and other problems, and the service life is long, reducing maintenance costs.

[0039] As attached Figure 10-11As shown, the aerogel felt 220 is filled between the first cover plate 200 and the cold plate 260, and the semiconductor refrigeration sheet 250 is placed between the cold plate 260 and the first cover plate 200, so there is a gap between the two. The gap is filled with aerogel felt 220 to make the device airtight. At the same time, the aerogel felt 220 has a heat-insulating effect, so the semiconductor refrigeration sheet 250 can completely transfer the cooling effect to the cold plate 260. At the same time, the heat at the hot end is transferred to the outside of the device through the first cover plate 200, so that the device has good cooling and heat transfer effects, and the temperature in the oil chamber 232 is further reduced.

[0040] As attached Figure 1 As shown, the drill collar 100 is provided with a first sealing groove 110 for accommodating a first sealing ring. The first sealing groove 110 is used to place the first sealing ring. The first sealing ring can increase the sealing performance of the connection between the drill collar 100 and the first cover body after they are covered, thereby preventing impurities such as fracturing fluid or return fluid from entering the device during downhole operations and causing damage to the device.

[0041] As attached Fig.11 As shown, the shell 230 is provided with a second sealing groove 231 for accommodating a second sealing ring. The second sealing groove 231 is used to place the second sealing ring. The second sealing ring can increase the sealing performance between the cold guide plate 260 and the shell 230, prevent the coolant in the oil chamber 232 from flowing out, and increase the cooling effect.

[0042] As attached Figure 1 As shown, the battery compartment 350 is provided with a third sealing groove 351 for accommodating a third sealing ring, which can increase the sealing performance of the housing 230 and the second cover plate 300 and prevent drilling fluid from entering the battery compartment 350 and causing damage to the battery 320 .

[0043] When in use, before the shell 230 is placed in the receiving groove 120, the outer wall of the shell 230 is coated with aerogel felt 220 so that it covers the shell 230. Before the cold conduction plate 260 is fixed, the second sealing ring is placed in the second sealing groove 231. The second sealing ring can also be aerogel felt 220. After filling, the cold conduction plate 260 is fixed. After the semiconductor refrigeration sheet 250 is placed, the surrounding area is filled with aerogel felt 220, and then the first cover plate 200 is laid on the semiconductor refrigeration sheet 250. Before the first cover plate 200 is fixed to the drill shank 100, the first sealing ring is placed in the first sealing groove 110. The first sealing ring can also be aerogel felt 220. After filling, the first cover plate 200 and the drill shank 100 are fixedly connected. In this way, the device has high sealing performance, and the connection between the components is tighter, reducing the occurrence of loosening and dislocation.

[0044] Example 3

[0045] Please refer to Fig.15 , Fig.15 FIG. 4 is a schematic diagram of a test system according to an embodiment of the present invention.

[0046] As attached Fig.15 As shown, on the basis of the above embodiments, in order to test the cooling effect of TEC and obtain the current and voltage data required to reach the set temperature, this embodiment 3 provides a test system for a downhole PCB board cooling device based on TEC semiconductor refrigeration technology, including a DC regulated power supply 400, an adjustable DC power supply 500, a temperature sensor 600, a test device 700, a constant temperature container 800, a thermal oil pump 900, a data acquisition instrument 1000 and an auxiliary heating device. The test device 700 is a simplified drill collar tool and integrates a PCB board cooling module, which is placed in a constant temperature container 800, and the constant temperature container 800 is filled with high-temperature thermal oil, which is heated by an auxiliary heating device to simulate the downhole 20 0℃ environment, the PCB board refrigeration module is electrically connected to the DC regulated power supply 400 and the adjustable DC power supply 500 outside the constant temperature container 800, the DC regulated power supply 400 supplies power to the PCB board 270 and the temperature sensor 600, the adjustable DC power supply 500 independently controls the current of the semiconductor refrigeration plate 250 to achieve proportional regulation, the temperature sensor 600 is located in the constant temperature container 800, and the temperature sensor 600 is electrically connected to the DC regulated power supply 400, the output end of the thermal oil pump 900 is connected to the constant temperature container 800 through a first pipeline, and the input end is connected to the constant temperature container 800 through a second pipeline, and another temperature sensor 600 is also provided in the PCB board 270 on the cold end side of the TEC and in the shell 230.

[0047] When in use, the thermal oil is pumped into the constant temperature container 800 through the thermal oil pump 900, so that the temperature in the constant temperature container 800 reaches 200°C. At the same time, the second pipeline transfers the thermal oil from the input end of the thermal oil pump 900 back to the thermal oil pump 900 to form a circulation, so as to stabilize the temperature in the constant temperature container 800 and simulate the high temperature environment underground. After the temperature is maintained at 200°C, the semiconductor refrigeration sheet 250 is turned on to start cooling, and the current and voltage increase proportionally until the PCB board 270 is stably cooled to 175°C. The current and voltage data at this time are obtained to provide a reference for the selection of the battery 320.

[0048] Example 4

[0049] On the basis of Example 3, this Example 4 provides a method for testing a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology, comprising the following steps: S1. Pour heat transfer oil into the constant temperature container 800, the liquid level covers the test device 700, start the auxiliary heating device 1100, set the target temperature to 200°C, then start the heat transfer oil pump 900 to circulate, monitor the heat transfer oil temperature, and stabilize the heat transfer oil temperature at 200°C for 10 minutes, which is considered to be the ambient temperature meeting the standard; S2. Turn off the cooling power supply and only turn on the PCB board 270 to simulate heating, wherein the heating is powered by the DC stabilized power supply 400, and the initial temperature, steady-state temperature and time to reach thermal equilibrium of the PCB board 270 are recorded. The system thermal resistance is calculated by formula 1 based on these data. Formula 1: Formula 1, where R is the system thermal resistance, in ℃ / W; T 1 is the steady-state temperature in °C; T env is the ambient oil temperature, in °C; P heat is the heating power, in W; S3. Test the cooling performance of the device, turn on the adjustable DC power supply 500, gradually increase the TEC current with a step unit of 0.5A, adjust it several times until the temperature of the PCB board 270 is stable, record the TEC input current, voltage, TEC cold end side PCB board 270 temperature and ambient oil temperature in real time, and calculate the cooling capacity and COP (cooling efficiency) by equation 2 and equation 3. Equation 2 and equation 3: Formula 2, Formula 3, where Q cool is the cooling capacity, in W; T cold is the 270°C temperature of the PCB board at the cold end of the TEC, in °C; COP is the cooling efficiency, dimensionless; I is the input current, in A; V is the input voltage, in V; S4. Extreme working condition verification, continuously increase the TEC current until the PCB board temperature reaches 175℃, record the critical parameters, maintain this working condition for 2h, and observe the temperature stability and whether the TEC fails; S5. Sort and optimize the data, generate a current-voltage-temperature relationship table, extract conclusions, determine the minimum current value that satisfies ΔT=25℃, and recommend the optimal TEC operating range.

[0050] Different input currents are tested through the above steps, and the test results are shown in Table 1: Table 1 Current-voltage-temperature relationship table

[0051] From the above results, we can see that when the current increases from 1A to 3A, the PCB board temperature drops from 195℃ to 175℃, and the cooling capacity increases from 1.5W to 16.5W, which meets the cooling target of ΔT=25℃. Therefore, the input current of 3A is the minimum current value that meets the cooling requirement of ΔT=25℃. The table shows that the best COP range occurs when the current is 2.5A-3A (COP>1), which is the most efficient operating condition of the TEC operation process. After the current is greater than 3A, the temperature drop rate slows down. This table can be used for battery selection to ensure that the cooling system operates under efficient and stable conditions.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology, characterized in that: include: A drill string body, the drill string body comprising a drill collar and a first cover plate, the drill collar is provided with a receiving groove for receiving a PCB board cooling module, the first cover plate is arranged at the mouth of the receiving groove, and the first cover plate is connected to the drill collar; The PCB board refrigeration module includes a shell, a cold plate, a PCB board and a plurality of semiconductor refrigeration sheets. The shell is provided with an oil cavity. The cold plate cover is arranged at the mouth of the oil cavity and abuts against the shell. The PCB board is located in the oil cavity and connected to the inner wall of the cold plate. The cold ends of the plurality of semiconductor refrigeration sheets are all connected to the cold plate. The hot ends of the plurality of semiconductor refrigeration sheets are all abutted against the first cover body. The oil cavity is filled with coolant.

2. According to claim 1, a downhole PCB board refrigeration device based on TEC semiconductor refrigeration technology is characterized in that: The drill string body also includes a second cover plate. A battery compartment for accommodating batteries is provided on the drill collar. The second cover plate is disposed at the mouth of the battery compartment. The second cover plate is connected to the drill collar.

3. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 2 is characterized in that: The drill collar is also provided with a socket hole for accommodating an aviation socket, one end of the socket hole is connected to the battery compartment, and the other end is connected to the accommodating groove, the aviation socket is electrically connected to the battery, and the aviation socket is also electrically connected to the PCB board and the plurality of semiconductor cooling plates.

4. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 1 is characterized in that: An aerogel felt is circumferentially arranged on the outer side wall of the shell.

5. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 1 is characterized in that: Aerogel felt is filled between the first cover plate and the cooling plate.

6. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 1 is characterized in that: The drill collar is provided with a first sealing groove for accommodating a first sealing ring.

7. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 1 is characterized in that: The housing is provided with a second sealing groove for accommodating a second sealing ring.

8. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 2 is characterized in that: The battery compartment is provided with a third sealing groove for accommodating a third sealing ring.

9. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 1, characterized in that: The drill collar is also provided with a wire outlet hole for accommodating the wires, the wire outlet hole is communicated with the accommodating groove, and the wire outlet hole is filled with sealant.

10. The underground PCB board refrigeration device based on TEC semiconductor refrigeration technology according to claim 2, characterized in that: The drill collar and the first cover plate are connected by a first cylindrical head screw; the drill collar and the second cover plate are connected by a second cylindrical head screw.

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