JP2016042063A - Survey device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a survey device capable of operating an electronic circuit at an environmental temperature of 40°C or higher without using an element having a special specification.SOLUTION: A survey device has: a sensor 8 used at an environmental temperature of 40°C or higher; a sensor control circuit 9 including a control circuit for controlling the sensor 8 and a transmitter-receiver circuit; a vacuum insulation container 6 which is a vacuum insulation Dewar for immersing the sensor 8 into liquid nitrogen 7 and storing it, and storing the sensor control circuit 9 on a furthermore upper part than a liquid level of the liquid nitrogen 7; and a pressure-resistant envelope 1 for storing the vacuum insulation container 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exploration device, and for example, relates to an exploration device that is required to have an environmental resistance performance used in the sea and in a well, particularly a heat resistance performance used in an environment exceeding 40 ° C.

In deep exploration exceeding 1000m underground, the water temperature in the well rises, and at 3000m underground, sensing in an environment up to 200 ° C may be required. In order to enable sensing in such an environment, a technology for protecting the built-in sensors and electronic circuits from heat is required. For example, heat resistance is important in CO ₂ injection monitoring, shale gas monitoring, and hydrothermal exploration technology for oil production technology.

  Conventionally, in order to drive a sensor and a control circuit in a high temperature environment, heat insulation is performed using super insulation (aluminum deposited on a film) or the like. In addition, sensors and circuit components with heat resistance were used.

  However, this technology cannot cope with the field of resource exploration. For example, in the underground exploration extending to 3000m underground and exploration in the hydrothermal deposit, the ultimate temperature reaches 200 ° C.

Special skill No.264, p.92-p.100,2012.01

  Conventionally, the present inventors have used exploration devices using CFRP (Carbon Fiber Reinforced Plastic) as a pressure vessel for a superconducting quantum interference device used in the sea and in a well (see, for example, Japanese Patent Application No. 2013-134809). .

  FIG. 10 is a schematic configuration diagram of an exploration device proposed by the present inventor, in which a high-pressure vessel including a high-pressure frame 41 sintered with CFRP, a tip cap member 42, and a cap member 54 is provided with vibration isolation. A vacuum insulating glass dewar 44 is accommodated through the foamed gel 43. Liquid nitrogen 45 is injected into the vacuum heat insulating glass dewar 44, and SQUID 47 attached to the tip of the probe 46 is inserted and immersed in the liquid nitrogen 45.

  On the other hand, the SQUID control circuit 49 provided with the FLL (Flux Locked Loop) circuit 50 and the transmission / reception circuit 51 connected by the communication cable 52 uses a cryostat structure arranged outside the vacuum heat insulating glass dewar 44. This structure has a sufficient withstand voltage performance, and each component other than an electronic circuit such as a SQUID control circuit is configured at a heat resistant temperature of 250 ° C.

  However, when an exploration device equipped with a high pressure resistant container is put in a 200 ° C. environment, an electronic circuit part that is not protected against heat insulation easily exceeds 100 ° C. and becomes damaged or malfunctions. The electronic circuit has a guaranteed temperature of normal parts of -20 ° C to 40 ° C. Therefore, when a normal 40 ° C. heat-resistant electronic circuit is continuously used in an environment where the environmental temperature exceeds 40 ° C., the temperature of the electronic circuit rises to 40 ° C. or more, and normal operation becomes difficult.

  Here, with reference to FIG.11 and FIG.12, the temperature rise condition at the time of throwing the pressure vessel provided with the high pressure vessel into a 200 degreeC environment is demonstrated. FIG. 11 is an explanatory view of the temperature rise test of the exploration device proposed by the present inventor. The exploration device using the high pressure vessel shown in FIG. 10 is inserted into a heating furnace 55 equipped with a heater. Then, the heater temperature is raised to 200 ° C., and the temperature rise of each part is measured.

  FIG. 12 is an explanatory view of the temperature rise test result of the exploration device proposed by the present inventor. The heater reaches a set temperature of 200 ° C. in about 100 minutes, and at the same time, a high pressure frame, that is, an outer wall The temperature reaches 200 ° C. in about 200 minutes. On the other hand, the FLL circuit section exceeds 40 ° C. in about 30 minutes. The SQUID part immersed in liquid nitrogen maintains a temperature in the vicinity of −196 ° C., which is the boiling point of liquid nitrogen, for about 250 minutes, and the temperature rises with a decrease due to vaporization of liquid nitrogen. In addition, the heat insulating material portion arranged in the vicinity of the liquid nitrogen surface is lowered to about −40 ° C. when the liquid nitrogen is actively evaporating, and then the temperature gradually rises as the ambient temperature rises. After 200 minutes, the temperature reached 50 ° C. This suggests that the temperature rise can be suppressed by enclosing the electronic circuit in the glass dewar.

  In particular, when an electronic circuit is configured with an element having heat resistance, there is an electronic circuit having an operating temperature of -20 ° C to 80 ° C. The use of such specially-designed elements hinders the degree of freedom in circuit design and becomes expensive, and it is still difficult to produce an electronic circuit that can withstand 200 ° C.

  Accordingly, it is an object of the present invention to realize an exploration device capable of operating an electronic circuit at an environmental temperature of 40 ° C. or higher without using a specially designed element.

  From one aspect to be disclosed, a sensor used at an environmental temperature of 40 ° C. or higher, a sensor control circuit including a control circuit and a transmission / reception circuit for controlling the sensor, and the sensor is immersed in liquid nitrogen and accommodated, and There is provided an exploration device comprising: a vacuum heat insulating container that houses a sensor control circuit above the liquid nitrogen surface; and a pressure-resistant envelope that houses the vacuum heat insulating container.

  According to the disclosed exploration device, an electronic circuit can be operated at an environmental temperature of 40 ° C. or higher without using a specially-designed element.

It is explanatory drawing of the search apparatus of embodiment of this invention. It is a schematic block diagram of the search device of Example 1 of this invention. It is a schematic block diagram of the search apparatus of Example 2 of this invention. It is a schematic block diagram of the search apparatus of Example 3 of this invention. It is a schematic block diagram of the search apparatus of Example 4 of this invention. It is a schematic block diagram of the search apparatus of Example 5 of this invention. It is a schematic block diagram of the search apparatus of Example 6 of this invention. It is a schematic block diagram of the search apparatus of Example 7 of this invention. It is a schematic block diagram of the search apparatus of Example 8 of this invention. It is a schematic block diagram of the search device which this inventor has proposed. It is explanatory drawing of the temperature rise test of the exploration apparatus which this inventor has proposed. It is explanatory drawing of the temperature rise test result of the search device which this inventor has proposed.

  Here, with reference to FIG. 1, the exploration device according to the embodiment of the present invention will be described. FIG. 1 is an explanatory diagram of a search device according to an embodiment of the present invention. The exploration device of the present invention includes a sensor 8 used at an environmental temperature of 40 ° C. or higher, a sensor control circuit 9 including a control circuit for controlling the sensor 8 and a transmission / reception circuit, a vacuum heat insulating container 6 for storing liquid nitrogen 7, and a vacuum. A pressure-resistant envelope 1 that accommodates the heat insulating container 6 is provided. In the present invention, the sensor 8 and the sensor control circuit 9 are accommodated in the vacuum heat insulating container 6, the sensor 8 is immersed and accommodated in the liquid nitrogen 7, and the sensor control circuit 9 is above the liquid surface of the liquid nitrogen 7. To house. The sensor 8 is typically a high temperature superconducting SQUID (quantum interferometer).

  The pressure envelope 1 includes a hollow cylindrical frame 2, a front end cap member 3, and a rear end cap member 4. The hollow cylindrical frame 2 may be any non-magnetic material, but is preferably a member having an environmental pressure resistance of 10 MPa, particularly a hollow cylindrical frame formed of a CFRP sintered body. Further, the front end cap member 3 and the rear end cap member 4 are preferably formed of a material having a heat resistant temperature of 200 ° C. or higher. For example, PEEK (polyether ether ketone) agent, PPS (polyphenyl sulfide), RENY (crystallinity) Highly heat-resistant plastic such as engineering plastic (registered trademark) is desirable.

  The vacuum heat insulating container 6 may be a stainless steel vacuum heat insulating dewar or a glass vacuum heat insulating dewar. In the case of a stainless steel vacuum heat insulation dewar, the degree of freedom of design shape is large and the mechanical strength is sufficient, but the heat insulation is not sufficient. On the other hand, in the case of a glass vacuum insulation dewar, although the heat insulation is sufficient, the degree of freedom of the design shape is small and the mechanical strength is not sufficient, and a glass vacuum insulation dewar having a length of 100 cm or more is produced. It is difficult.

  Moreover, in order to improve heat insulation, you may provide the heat insulating material 10 in the upper part of the liquid level of the liquid nitrogen 7. FIG. As the heat insulating material 10, a styrofoam or a melamine foam may be used. Further, in order to enhance the heat insulation, a hollow cylindrical vacuum heat insulating member having a glass double tube structure may be provided above and below the sensor control circuit 9. In addition to Pyrex (registered trademark), quartz glass or the like can be used for these glasses. In this case, when the vacuum heat insulating container 6 is a glass vacuum heat insulating dewar, the sensor control circuit 9 may be excessively cooled. Therefore, even if a temperature control heating means is provided in the vicinity of the sensor control circuit 9. good.

  Moreover, in order to form the vacuum heat insulating device 6 having a length of 100 cm or more and excellent heat insulating properties, a separation structure using two vacuum heat insulating dewars is used. For example, a hollow vacuum stainless steel vacuum dewar having a double tube structure may be connected to a glass vacuum heat insulation dewar containing liquid nitrogen 7 in the long axis direction of the glass heat insulation dewar. In this case, the sensor control circuit 9 is accommodated in a stainless steel vacuum heat insulating dewar having a hollow cylindrical shape with a double tube structure.

  Alternatively, a glass vacuum heat insulation dewar having a double tube structure may be connected to the glass heat insulation dewar containing the liquid nitrogen 7 in the major axis direction by welding to the glass heat insulation dewar. In this case, the sensor control circuit 9 is accommodated in a hollow cylindrical glass vacuum heat insulating dewar having a double tube structure. In the case of these separation structures, the inside diameter of the through vacuum insulation dewar may be larger than the inside diameter of the glass vacuum insulation dewar, and when an evaporating nitrogen exhaust pipe or a cooling refrigerant circulation pipe is provided in the through vacuum insulation dewar. , The degree of freedom of arrangement can be increased.

  When the vacuum heat insulating container 6 becomes longer, the temperature of the sensor control circuit 9 accommodated above the liquid nitrogen 7 surface is likely to rise. Therefore, an evaporated nitrogen exhaust pipe for discharging the evaporated nitrogen evaporated from the liquid nitrogen 7 to the outside of the pressure-resistant envelope 1 and cooling the sensor control circuit 9 may be provided so as to pass through the vicinity of the sensor control circuit. .

  Alternatively, a circuit cooling refrigerant circulation pipe that circulates and supplies a refrigerant for cooling the sensor control circuit 9 from outside the pressure-resistant envelope 1 may be provided in the vicinity of the sensor control circuit 9. Alternatively, since a Peltier effect element that operates in an environment of 200 ° C. has recently appeared, even if the sensor control circuit 9 is fixed to the sensor control circuit 9 while being in contact with the sensor control circuit 9 and the sensor control circuit 9 is cooled as necessary, good. When the vicinity of the sensor control circuit 9 is lower than the proper operating temperature, heating may be performed with the direction of the current flowing through the Peltier effect element reversed.

  Thus, in the embodiment of the present invention, since the sensor control circuit 9 is accommodated in the vacuum heat insulating container 6, even when the environmental temperature is 40 ° C. or higher, the guaranteed operation temperature is −20 ° C. to The sensor control circuit 9 using a normal electronic circuit of 40 ° C. operates properly.

  As a result, it is possible to provide a high pressure and heat resistant cryostat capable of driving an underground resource exploration and underground monitoring sensor including a high temperature superconducting SQUID even in a high temperature environment of 40 ° C. or higher. As a result, it can make an extremely high technical contribution to the resources and energy fields including oil, natural gas, and EOR (Enhanced Oil Recovery Technology).

  Next, with reference to FIG. 2, the exploration device according to the first embodiment of the present invention will be described. FIG. 2 is a schematic configuration diagram of the exploration device according to the first embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure-resistant frame 11 made of a CFRP sintered body and an O-ring (both not shown). To form a high voltage envelope. A stainless steel vacuum dewar 14 is inserted through the vibration-proof foam gel 13 into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the stainless steel vacuum dewar 14, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper part of the liquid nitrogen 15 is thermally insulated with a heat insulating material 18 using a styrofoam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is provided above the heat insulating material 18 of the stainless steel vacuum dewar 14. Arrange and connect with the communication cable 22. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  Thus, in Example 1 of the present invention, since the SQUID control circuit 19 is housed above the liquid nitrogen 15 level of the stainless steel vacuum dewar 14, even if the environmental temperature rises to 40 ° C. or higher, The temperature of the SQUID control circuit 19 can be maintained at −20 ° C. to 40 ° C., which is the operation guarantee temperature of a normal electronic circuit.

  Further, since a stainless steel vacuum dewar is used as the vacuum heat insulating container, the design shape is flexible and handling is easy. On the other hand, since the heat wraparound is inferior to glass dewar, it is suitable for use in a relatively low temperature environment.

  Next, with reference to FIG. 3, the exploration device according to the second embodiment of the present invention will be described. FIG. 3 is a schematic configuration diagram of an exploration device according to a second embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure resistant frame 11 made of a CFRP sintered body and an O-ring (not shown). To form a high voltage envelope. A stainless steel vacuum dewar 14 is inserted through the vibration-proof foam gel 13 into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the stainless steel vacuum dewar 14, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper part of the liquid nitrogen 15 is thermally insulated by a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 in a region above the heat insulating material 18 of the stainless steel vacuum dewar 14. Are connected by a communication cable 22. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown). At this time, hollow cylindrical vacuum heat insulating members 25 and 26 having a glass double tube structure are provided so as to sandwich the SQUID control circuit 19 from above and below.

  Thus, also in Example 2 of the present invention, since the SQUID control circuit 19 is accommodated above the liquid nitrogen 15 level of the stainless vacuum dewar 14, even if the environmental temperature rises to 40 ° C. or higher, The temperature of the SQUID control circuit 19 can be maintained at −20 ° C. to 40 ° C., which is the operation guarantee temperature of a normal electronic circuit.

  In addition, the hollow cylindrical vacuum heat insulating members 25 and 26 are provided in a glass double tube structure so as to sandwich the SQUID control circuit 19 from above and below, thereby improving the heat insulating property of the arrangement area of the SQUID control circuit 19. . As a result, even if the environmental temperature rises, the temperature rise of the SQUID control circuit 19 can be more efficiently suppressed.

  Next, with reference to FIG. 4, the exploration device according to the third embodiment of the present invention will be described. In the third embodiment, the stainless steel vacuum dewar of the second embodiment is replaced with a vacuum heat insulating glass dewar, and the SQUID control circuit. A heater is provided in the vicinity. FIG. 4 is a schematic configuration diagram of an exploration device according to a third embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure resistant frame 11 made of a CFRP sintered body, and an O-ring (not shown). To form a high voltage envelope. A vacuum heat insulating glass dewar 27 is inserted into the high pressure resistant envelope through the antivibration foam gel 13. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 27, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper part of the liquid nitrogen 15 is thermally insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 in a region above the heat insulating material 18 of the vacuum heat insulating glass dewar 27. Are connected by a communication cable 22. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown). At this time, vacuum cylindrical heat insulating members 25 and 26 having a glass double tube structure are provided so as to sandwich the SQUID control circuit 19 from above and below, and a temperature control heater 28 is disposed in the vicinity of the SQUID control circuit 19. To do.

  Since the third embodiment is premised on use in a situation where the environmental temperature is higher than that of the first embodiment, the tip cap member 12 is a tip cap member made of PPS having a heat resistant temperature of 260 ° C. Is used. In addition, as the other anti-vibration foam gel 13 and the heat insulating seal material 23, a material having a heat resistant temperature of 200 ° C. or more is used.

  Thus, also in Example 3 of the present invention, since the SQUID control circuit 19 is housed above the liquid nitrogen 15 liquid surface of the vacuum heat insulating glass dewar 27, even if the environmental temperature rises to 40 ° C. or higher, The temperature of the SQUID control circuit 19 can be maintained at −20 ° C. to 40 ° C., which is the operation guarantee temperature of a normal electronic circuit.

  However, since the heat insulation is good, there is a possibility that the temperature of the arrangement area of the SQUID control circuit 19 is too lower than the proper operating temperature of the electronic circuit. In that case, the SQUID control circuit 19 can be kept within the range of the correction operation temperature by being heated by the temperature control heater 28.

  Next, with reference to FIG. 5, the exploration device according to the fourth embodiment of the present invention will be described. The vacuum heat insulating container has a two-stage separation structure. FIG. 5 is a schematic configuration diagram of an exploration device according to a fourth embodiment of the present invention. A tip cap member 12 is screwed into a high pressure resistant frame 11 made of a CFRP sintered body and an O-ring (both not shown). To form a high voltage envelope. A vacuum heat insulating glass dewar 29 is inserted into the high pressure resistant envelope through the antivibration foam gel 13, and a through vacuum heat insulating stainless steel dewar 30 having a double tube structure is joined to the upper portion of the vacuum heat insulating glass dewar 29. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 29, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper part of the liquid nitrogen 15 is thermally insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is arranged in a through vacuum heat insulating stainless steel dewar 30 for communication. Connect with cable 22. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  Since the fourth embodiment is also premised on use in a situation where the environmental temperature is higher than that of the first embodiment, the tip cap member 12 is made of a PPS tip cap member having a heat resistant temperature of 260 ° C. Is used. In addition, as the other anti-vibration foam gel 13 and the heat insulating seal material 23, a material having a heat resistant temperature of 200 ° C. or more is used.

  Since the vacuum heat insulating glass dewar has a structure in which the inner glass and the outer glass are combined only at the end portion, the strength becomes weaker when the size becomes larger in the length direction. For example, in a glass dewar having an outer diameter of 55 mm and an inner diameter of 40 mm, a length of 1 m is the limit. However, in Example 4 of this invention, since it is set as the isolation | separation structure using the penetration vacuum heat insulation stainless steel dewar 30, the long vacuum heat insulation container of 1 m or more can be created.

  In addition, the separation structure makes maintenance easy. In addition, it becomes easy to change the diameter of the heat insulating container between the arrangement part of the SQUID control circuit 19 and the arrangement part of the probe 16, and the design freedom of the cryostat is expanded. Other functions and effects are the same as those of the first embodiment.

  Next, with reference to FIG. 6, the exploration device according to the fifth embodiment of the present invention will be described. The vacuum heat insulating container has a two-stage separation structure made of glass. FIG. 6 is a schematic configuration diagram of an exploration device according to a fifth embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure frame 11 made of a CFRP sintered body and a screw fitting portion and an O-ring (both not shown). To form a high voltage envelope. A vacuum heat insulating container in which a vacuum heat insulating glass dewar 29 and a through vacuum heat insulating glass dewar 31 are welded and integrated with each other through a vibration isolating foam gel 13 is inserted into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 29, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper surface of the liquid nitrogen 15 is insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is arranged in a through-vacuum heat insulating glass dewar 31 to provide a communication cable. 22 is connected. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  Since the fifth embodiment is also premised on use in a situation where the environmental temperature is higher than that of the first embodiment, the tip cap member 12 is made of a PPS tip cap member having a heat resistant temperature of 260 ° C. Is used. In addition, as the other anti-vibration foam gel 13 and the heat insulating seal material 23, a material having a heat resistant temperature of 200 ° C. or more is used.

  Further, since the vacuum heat insulating container is formed by welding the vacuum heat insulating glass dewar 29 and the through vacuum heat insulating glass dewar 31, a vacuum heat insulating container having a length of 1 m or more can be realized. Moreover, since the upper stage part is formed with the penetration vacuum heat insulation glass dewar, the heat insulation of the arrangement | positioning part of the SQUID control circuit 19 can be improved more compared with said Example 4. FIG.

  Next, with reference to FIG. 7, the exploration device according to the sixth embodiment of the present invention will be described. The sixth embodiment is the above-described fifth embodiment provided with an evaporative nitrogen exhaust pipe, and the other structures are the same as those described above. The same as in the fifth embodiment. FIG. 7 is a schematic configuration diagram of an exploration device according to a sixth embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure-resistant frame 11 made of a CFRP sintered body and a screw fitting portion and an O-ring (both not shown). To form a high voltage envelope. A vacuum heat insulating container in which a vacuum heat insulating glass dewar 29 and a through vacuum heat insulating glass dewar 31 are welded and integrated with each other through a vibration isolating foam gel 13 is inserted into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 29, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper surface of the liquid nitrogen 15 is insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is arranged in a through-vacuum heat insulating glass dewar 31 to provide a communication cable. 22 is connected. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  In the sixth embodiment, the evaporated nitrogen exhaust pipe 33 for evaporating the liquid nitrogen 15 and discharging low temperature nitrogen out of the high pressure vessel is formed in a coiled shape at the arrangement portion of the SQUID control circuit 19. The evaporated low temperature nitrogen can efficiently cool the SQUID control circuit 19 to an appropriate operating temperature while passing through the evaporated nitrogen discharge pipe 33. The shape of the evaporated nitrogen discharge pipe 33 may be a coiled shape or a meandering shape.

  In order to operate the system in a high temperature environment for a long time, waste heat is also important as well as heat insulation. In the case of SQUID, liquid nitrogen is inevitably included, but even when the sensor itself does not require cooling to a low temperature, liquid nitrogen can be included and used for waste heat. As in the case of SQUID, in addition to the case of using naturally evaporated nitrogen, it is also possible to cool by cooling by forcibly evaporating a heater in liquid nitrogen for temperature control.

  The evaporative nitrogen discharge pipe 33 can be made of a nonmagnetic metal having excellent heat conduction, such as copper, aluminum, or brass, or a carbon tube. Further, in addition to the method of circulating the piping, a nozzle structure may be provided for the circuit so as to promote efficient cooling.

  Next, with reference to FIG. 8, the exploration device according to the seventh embodiment of the present invention will be described. In the seventh embodiment, a circuit circulation refrigerant circulation pipe for supplying a refrigerant from the outside is provided in the fifth embodiment. The other structure is the same as that of the fifth embodiment. FIG. 8 is a schematic configuration diagram of an exploration device according to a seventh embodiment of the present invention, in which a tip cap member 12 is screwed into a high pressure resistant frame 11 made of a CFRP sintered body and an O-ring (both not shown). To form a high voltage envelope. A vacuum heat insulating container in which a vacuum heat insulating glass dewar 29 and a through vacuum heat insulating glass dewar 31 are welded and integrated with each other through a vibration isolating foam gel 13 is inserted into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 29, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper surface of the liquid nitrogen 15 is insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is arranged in a through-vacuum heat insulating glass dewar 31 to provide a communication cable. 22 is connected. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  In the seventh embodiment, the circuit-cooling refrigerant circulation pipe 34 that circulates and supplies refrigerant from the outside is formed in a coiled shape at the arrangement portion of the SQUID control circuit 19. By circulating pure water as a refrigerant in the circuit cooling refrigerant circulation pipe 34, the SQUID control circuit 19 can be efficiently cooled to an appropriate operating temperature. The shape of the circuit cooling refrigerant circulation pipe 34 may be a coiled shape or a meandering shape.

  The circuit cooling refrigerant circulation pipe 34 may be made of a nonmagnetic metal, such as copper, aluminum, brass or the like, which has excellent heat conduction, or a carbon tube. Moreover, as a refrigerant | coolant, you may use the pure water etc. which added the rust preventive material other than a pure water.

  If the heat insulation performance with respect to liquid nitrogen is improved, the amount of evaporated nitrogen decreases accordingly, and there may be a case where sufficient nitrogen cannot be secured for cooling the circuit. However, in the seventh embodiment of the present invention, since the circuit cooling refrigerant circulation pipe 34 is provided and the refrigerant from the ground is sent and circulated, the structure is complicated, but the heat resistance is guaranteed for the longest time. can do.

  Next, with reference to FIG. 9, a description will be given of an exploration device according to an eighth embodiment of the present invention. In the eighth embodiment, the PQUIER effect element is fixed to the SQUID control circuit in the fifth embodiment, and the other structures are described. Is the same as in Example 5 above. FIG. 9 is a schematic configuration diagram of an exploration device according to an eighth embodiment of the present invention. A tip cap member 12 is screwed to a high pressure resistant frame 11 made of a CFRP sintered body and an O-ring (both not shown). To form a high voltage envelope. A vacuum heat insulating container in which a vacuum heat insulating glass dewar 29 and a through vacuum heat insulating glass dewar 31 are welded and integrated with each other through a vibration isolating foam gel 13 is inserted into the high pressure resistant envelope. Liquid nitrogen 15 is injected into the vacuum heat insulating glass dewar 29, and the SQUID 17 attached to the tip of the probe 16 is immersed in the liquid nitrogen 15.

  Further, the upper surface of the liquid nitrogen 15 is insulated with a heat insulating material 18 using melamine foam, and a SQUID control circuit 19 including an FLL circuit 20 and a transmission / reception circuit 21 is arranged in a through-vacuum heat insulating glass dewar 31 to provide a communication cable. 22 is connected. Next, the cap member 24 is fitted through the heat insulating sealing material 23 using a screw fitting portion and an O-ring (both not shown).

  In the eighth embodiment, the Peltier effect elements 35 and 36 are fixed to the FLL circuit 20 and the transmission / reception circuit 21, and the FLL circuit 20 and the transmission / reception circuit 21 are appropriately cooled. In recent years, Peltier effect elements that can operate even at an environmental temperature of 200 ° C. or higher have appeared. By using such a Peltier effect element that can operate at a high temperature, SQUID control can be performed even at an environmental temperature of 200 ° C. or higher. The circuit 19 can be maintained at an appropriate operating temperature. As a result, long-term heat resistance can be guaranteed.

DESCRIPTION OF SYMBOLS 1 Pressure-resistant envelope 2 Hollow cylindrical frame 3 End cap member 4 Rear end cap member 5 Anti-vibration material 6 Vacuum heat insulating container 7 Base nitrogen 8 Sensor 9 Sensor control circuit 10 Heat insulating material 11, 41 High pressure frame 12, 42 Front end cap Members 13, 43 Anti-vibration foam gel 14 Stainless steel vacuum dewar 15, 45 Liquid nitrogen 16, 46 Probe 17, 47 SQUID
18, 48 Heat insulation material 19, 49 SQUID control circuit 20, 50 FLL circuit 21, 51 Transmission / reception circuit 22, 52 Communication cable 23, 53 Heat insulation seal material 24, 54 Cap member 25, 26 Vacuum heat insulation member 27, 29, 44 Vacuum heat insulation Glass dewar 28 Temperature control heater 30 Through-vacuum heat insulation stainless steel dewar 31 Through-vacuum heat insulation glass dewar 32 Welding portion 33 Evaporative nitrogen discharge pipe 34 Circuit cooling refrigerant circulation pipe 35, 36 Peltier effect element 55 Heating furnace

Claims (12)

A sensor for use at an ambient temperature of 40 ° C or higher;
A sensor control circuit including a control circuit for controlling the sensor and a transmission / reception circuit;
The sensor is immersed in liquid nitrogen and housed, and the sensor control circuit is housed above the liquid nitrogen liquid surface, and a vacuum insulation container,
An exploration device comprising a pressure-resistant envelope that accommodates the vacuum heat insulating container.   The exploration device according to claim 1, wherein the vacuum heat insulating container is a stainless steel vacuum heat insulating dewar.   The exploration device according to claim 1, wherein the vacuum heat insulating container is a glass vacuum heat insulating dewar.   The exploration device according to claim 2 or 3, further comprising a vacuum insulation member having a hollow cylindrical shape with a double tube structure above and below the sensor control circuit.   5. The exploration apparatus according to claim 4, wherein the vacuum heat insulating container is a glass vacuum heat insulating dewar, and is provided with heating means for temperature control in the vicinity of the sensor control circuit. The vacuum insulation container comprises a glass vacuum insulation dewar, and a hollow cylindrical stainless steel vacuum insulation dewar with a double tube structure connected to the glass insulation dewar in the long axis direction,
The exploration device according to claim 1, wherein the sensor control circuit is housed in a hollow cylindrical stainless steel vacuum heat insulation dewar having the double tube structure. The vacuum heat insulation container comprises a glass vacuum heat insulation dewar, and a glass tube heat insulation dewar having a hollow cylindrical shape having a double tube structure connected to the glass heat insulation dewar by a welded portion in the longitudinal direction.
The exploration device according to claim 1, wherein the sensor control circuit is housed in a hollow cylindrical glass vacuum heat insulating dewar having the double tube structure.   An evaporative nitrogen exhaust pipe that passes through the vicinity of the sensor control circuit and exhausts the evaporated nitrogen vaporized by the liquid nitrogen out of the pressure-resistant envelope and cools the sensor control circuit. Item 8. The exploration device according to Item 7.   8. The exploration according to claim 7, further comprising a circuit cooling refrigerant circulation pipe which is arranged in the vicinity of the sensor control circuit and circulates a refrigerant for cooling the sensor control circuit from outside the pressure-resistant envelope. apparatus.   The exploration device according to claim 7, wherein a Peltier effect element is fixed in contact with the sensor control circuit.   The exploration device according to any one of claims 1 to 10, wherein the sensor is a high-temperature superconducting quantum interferometer.   The exploration device according to any one of claims 1 to 11, wherein an environmental pressure resistance of the pressure envelope is 10 MPa or more.

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