Temperature Measuring Device and System for Electric Heating Furnace Based on Femtosecond Fiber Grating Temperature Sensor

Abstract

The present invention provides a temperature measuring device and system for an electric heating furnace based on a femtosecond fiber grating temperature sensor, including a junction box assembly, which includes a junction box body and a connector that are rotatably connected to each other. A locking nut is threadedly connected to the end of the connector. An end of the junction box body is fixedly connected with an optical fiber grating temperature measuring sleeve extending into the heating furnace; a retractable protection device, which is telescopically sleeved outside the optical fiber grating temperature measuring sleeve, and a fixed end of the retractable protection device is connected to the locking nut; a multi-directional damping protection device, which is arranged inside the retractable protection device, and the device is provided with a plurality of hydraulic damping units distributed circumferentially to elastically clamp the optical fiber grating temperature measuring sleeve. Through the retractable protection device, the contraction state of the optical fiber grating temperature measuring sleeve is electrically controlled to realize the free switching between the working state and the non-working state. Through the multi-directional damping protection device, the object inside the hollow cylindrical device can be protected to the greatest extent while reducing the occupied area.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of heating furnace temperature measurement, and specifically to a temperature measurement device and system for an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor. Background Technique

[0002] As a low-pressure and high-temperature heat supply device, the heat-conducting oil heating furnace has been widely used and developed in the fields of oil and gas, petrochemical, textile printing and dyeing, food and medicine, building materials, etc.; especially in the processes of natural gas treatment, light hydrocarbon recovery, oil and gas gathering and transportation, long-distance pipelines, condensate oil stabilization, etc., the heat-conducting oil heating furnace has gradually replaced traditional heating furnaces and steam heat supply equipment with its advantages of safety and high efficiency, convenient management, energy conservation and environmental protection, good heat transfer effect, accurate temperature control, and low operating cost, and has become the core heat supply equipment preferred for end-use energy in oil and gas fields.

[0003] At present, thermocouples are generally used for temperature measurement of heat-conducting oil heating furnaces, mainly in the form of sleeve-type thermocouples for temperature measurement. The thermocouple sleeve is fixed on the surface of the electric heating tube by a clamp to monitor the temperature at a certain point. The traditional temperature measurement device for electric heating furnaces can only collect the temperature of a single point on the surface of the electric heating tube. If multiple temperature points need to be measured, multiple thermocouple sleeves need to be set, reducing the layout space of the electric heating tubes;

[0004] To solve the above problems, a femtosecond fiber Bragg grating temperature sensing system can be used to realize the measurement of multiple temperature points and achieve array-type multi-point linear temperature measurement. However, there are also corresponding problems. Since the number of measurement points increases, the area that needs to be protected by the temperature measurement sensor sleeve increases, and it is necessary to prevent the loosening and damage of the electric heating tube caused by the scouring vibration of the fluid during operation. In view of this, we propose a temperature measurement device and system for an electric heating furnace. Summary of the Invention

[0005] The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art, and provide a temperature measurement device and system for an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor.

[0006] In a first aspect, the embodiments of the present invention provide a temperature measurement device for an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor, including:

[0007] A junction box assembly, the junction box assembly includes a junction box body and a connector that are rotatably connected to each other. A locking nut is threadedly connected to the end of the connector. An optical fiber Bragg grating temperature measurement sleeve extending into the heating furnace is fixedly connected to the end of the junction box body. A femtosecond fiber Bragg grating temperature sensor is accommodated in the optical fiber Bragg grating temperature measurement sleeve;

[0008] A retractable protective device, which is telescopically sleeved outside the fiber Bragg grating temperature measuring sleeve, and the fixed end of the retractable protective device is connected to a locking nut;

[0009] A multi-directional damping protection device, which is arranged inside the retractable protection device, and the multi-directional damping protection device is provided with a plurality of hydraulic damping units distributed circumferentially to elastically clamp the fiber Bragg grating temperature measuring sleeve.

[0010] In some possible embodiments, the retractable protective device includes:

[0011] A retractable sleeve that can be axially telescoped, and one end of the retractable sleeve is fixed to the end of the locking nut;

[0012] A fixed sleeve sleeved on the retractable sleeve, and the fixed sleeve forms a piston-type connection with the end of the retractable sleeve; a driving seal cavity is opened in the fixed sleeve, and an electric push rod and an annular air pressure plate connected to the output shaft of the electric push rod are installed on the fixed sleeve.

[0013] In some possible embodiments, the annular air pressure plate is piston-connected inside the fixed sleeve, a condensation spring tube is fixedly connected between the end of the fixed sleeve and the end of the retractable sleeve, and an exhaust hole is opened on the fixed sleeve.

[0014] In some possible embodiments, the hydraulic damping unit includes:

[0015] An oil storage cavity and a working cavity, both of which are opened in the fixed sleeve, and the inside of the oil storage cavity and the working cavity is communicated. The inside of the oil storage cavity is filled with hydraulic oil and compressed gas, and the inside of the working cavity is filled with hydraulic oil;

[0016] A total damping component and an external force pressing damping component, the total damping component is arranged in the oil storage cavity, the external force pressing damping component is arranged in the working cavity, and a plug rod and a protective arc plate fixedly connected to the outer end of the plug rod are arranged on the external force pressing damping component.

[0017] In some possible embodiments, the external force pressing damping component includes:

[0018] A piston plate, which is fixedly connected to the end of the plug rod;

[0019] A limit valve seat, which is fixedly connected to the side of the piston plate close to the plug rod;

[0020] A guide rod, which is fixedly connected inside the limit valve seat;

[0021] A valve disc, the valve disc is slidably connected to the guide rod, and a spring is fixedly connected between one end of the valve disc and the inside of the limit valve seat;

[0022] A valve plate, the valve plate is elastically connected to the side of the piston plate away from the plug rod.

[0023] In some possible embodiments, the surfaces of the piston plate and the valve plate are both piston-connected to the inner wall of the working chamber;

[0024] The piston plate is provided with a first valve hole at the position of the valve disc, the valve plate is provided with a second valve hole at the position of the first valve hole, and the piston plate is provided with a third valve hole misaligned with the first valve hole.

[0025] In some possible embodiments, the total damping assembly includes:

[0026] A fixed seat, the fixed seat is fixedly connected in the oil storage chamber;

[0027] An arc-shaped valve seat, the arc-shaped valve seat is elastically connected in the fixed seat;

[0028] A flow-limiting valve and a pressure valve, the flow-limiting valve is arranged on the arc-shaped valve seat, one end of the flow-limiting valve away from the arc-shaped valve seat is connected with the pressure valve, and the end of the pressure valve is elastically connected in the oil storage chamber.

[0029] In some possible embodiments, the end of the arc-shaped valve seat is piston-connected in the fixed seat;

[0030] The surface of the flow-limiting valve is fixedly connected to the inside of the oil storage chamber, the flow-limiting valve is respectively provided with a groove and an arc-shaped groove, and the pressure valve is provided with a concave cavity corresponding to the groove.

[0031] In some possible embodiments, a guiding hopper is fixedly connected inside the fixed sleeve, and a guiding angle is provided at one end of the protective arc plate close to the guiding hopper.

[0032] In a second aspect, an electric heating furnace temperature measurement system based on a femtosecond fiber grating temperature sensor provided by an embodiment of the present invention, based on the above-described electric heating furnace temperature measurement device, includes:

[0033] An instruction receiving module, configured to receive and analyze the temperature measurement instruction of the operator; wherein, the temperature measurement instruction carries a target expansion amount and a target damping coefficient;

[0034] A control module, the control module is electrically connected to the instruction receiving module, and is configured to adjust the expansion amount of the retractable protection device and the damping coefficient of the multi-directional damping protection device based on the target expansion amount and the target damping coefficient in the temperature measurement instruction;

[0035] An execution module, electrically connected to the control module, starts the retractable protection device to perform temperature measurement work after receiving the temperature measurement work information transmitted by the control module.

[0036] The temperature measurement device and system of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to an embodiment of the present invention realizes the measurement of multiple temperature points through a fiber Bragg grating temperature measurement sleeve, and achieves the effect of electrically controlling the retraction state of the fiber Bragg grating temperature measurement sleeve through a retractable protection device, and can realize the effect of freely switching between the working state and the non-working state. At the same time, the measurement position can be adjusted. By setting a multi-directional damping protection device, the damping force formed when each valve intercepts the flow is used to achieve shock absorption and buffering and prevent rebound effects, and can protect the object in the hollow cylindrical device to the greatest extent while reducing the occupied area, and can protect the cylindrical fiber Bragg grating temperature measurement sleeve in multiple directions, thereby avoiding the problem that the fiber Bragg grating temperature measurement sleeve is loosened and damaged due to the scouring vibration of the fluid during work.

[0037] Furthermore, in the temperature measurement device and system of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to an embodiment of the present invention, the output shaft of the electric push rod sucks and drives the gas in the sealed cavity through the annular air pressure plate, and the negative pressure generated by driving the sealed cavity drives the whole retractable sleeve to move downward. By controlling the movement distance of the output shaft of the electric push rod, the downward movement distance of the retractable sleeve can be adjusted, so that the whole fiber Bragg grating temperature measurement sleeve can move downward together with the connector and the locking nut. When moving downward, it realizes the effect of ejecting and measuring the temperature of the fluid in the heat-conducting oil furnace in the fixed sleeve, and at the same time, the measurement position can be adjusted, improving the applicability and practicability of the overall measurement. And by electrically controlling the retraction state of the fiber Bragg grating temperature measurement sleeve, the effect of freely switching between the working state and the non-working state can be realized, avoiding the inconvenience of the traditional manual adjustment of the connector for working state switching.

[0038] Furthermore, in the temperature measurement device and system of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to an embodiment of the present invention, the fiber Bragg grating temperature measurement sleeve is protected by a protective arc plate. When the fiber Bragg grating temperature measurement sleeve is loose, the loosening force acts on the protective arc plate, and the protective arc plate is pressed by the external force. The protective arc plate presses the damping component through the plug rod to squeeze the hydraulic oil into the oil storage cavity. During both the squeezing and pulling processes, it is affected by the damping force of the external force pressing the damping component and the total damping component. By using the throttling speed limit of each valve, shock absorption and buffering are realized. Therefore, the two functions of shock absorption and buffering and preventing rebound can achieve the effect of fully protecting the surface of the fiber Bragg grating temperature measurement sleeve, thereby avoiding the problem that the fiber Bragg grating temperature measurement sleeve is loosened and damaged due to the scouring vibration of the fluid during work. Description of the Drawings

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 Schematic diagram of the overall structure of the temperature measurement device for the electric heating furnace based on the femtosecond fiber grating temperature sensor according to the embodiment of the present invention;

[0041] Figure 2 Schematic diagram of the internal structure of the shrinkage sleeve according to the embodiment of the present invention;

[0042] Figure 3 Schematic diagram of the overall structure of the junction box according to the embodiment of the present invention;

[0043] Figure 4 Schematic diagram of the structure of the shrinkable protection device according to the embodiment of the present invention;

[0044] Figure 5 Schematic diagram of the structure at the oil storage cavity according to the embodiment of the present invention;

[0045] Figure 6 Schematic diagram of the structure of the multi-directional damping protection device according to the embodiment of the present invention;

[0046] Figure 7 Schematic diagram of the structure of the external force pressing damping component according to the embodiment of the present invention;

[0047] Figure 8 Schematic diagram of the structure at the guide rod according to the embodiment of the present invention;

[0048] Figure 9 Schematic diagram of the exploded structure of the total damping component according to the embodiment of the present invention;

[0049] Figure 10 Schematic diagram of the internal structure of the fixed sleeve according to the embodiment of the present invention;

[0050] Figure 11 Schematic diagram of the structure of the temperature measurement system for the electric heating furnace based on the femtosecond fiber grating temperature sensor according to the embodiment of the present invention.

[0051] In the figure:

[0052] 1. Junction box body; 2. Connector; 3. Locking nut; 4. Fiber Bragg grating temperature measuring sleeve; 5. Retractable protection device; 51. Shrinkage sleeve; 52. Fixed sleeve; 53. Driving seal cavity; 54. Electric push rod; 55. Annular air pressure plate; 56. Condensing bellows; 57. Guide hopper; 6. Hydraulic damping unit; 61. Oil storage cavity; 62. Working cavity; 63. Total damping assembly; 631. Fixed seat; 632. Arc-shaped valve seat; 633. Flow limiting valve; 634. Pressure valve; 635. Arc-shaped groove; 636. Concave cavity; 637. Groove; 64. External force pressing damping assembly; 641. Piston plate; 642. Limit valve seat; 643. Guide rod; 644. Valve disc; 645. Valve plate; 646. First valve hole; 647. Second valve hole; 648. Third valve hole; 65. Plug rod; 66. Protective arc plate. Detailed implementation manners

[0053] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0054] Unless otherwise specifically stated, the technical terms or scientific terms used in the embodiments of the present invention should be the ordinary meanings understood by those of ordinary skill in the art to which the present invention belongs. The "including" or "comprising" used in the embodiments of the present invention neither limits the mentioned shapes, numbers, steps, actions, operations, components, elements and / or their groups, nor excludes the appearance or addition of one or more other different shapes, numbers, steps, actions, operations, components, elements and / or their groups, or the addition of these. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity and order of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically and clearly defined.

[0055] Unless otherwise specifically stated, the relative settings, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for ease of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships, and technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail. In all the examples shown and discussed here, any specific other example may have different values. It should be noted that similar symbols and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0056] In the description of the embodiments of the present invention, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in the embodiments of the present invention and the features of different embodiments or examples.

[0057] Next, exemplary embodiments of the present invention will be described in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described here.

[0058] Embodiment 1

[0059] Please refer to Figures 1 to 11 As shown, a temperature measurement device for an electric heating furnace based on a femtosecond fiber grating temperature sensor includes a junction box assembly. The junction box assembly includes a junction box body 1 and a connector 2 that are rotatably connected to each other. A locking nut 3 is threadedly connected to the bottom end of the connector 2. An end of the junction box 1 is fixedly connected to an optical fiber grating temperature measurement sleeve 4, and the optical fiber grating temperature measurement sleeve 4 penetrates through the inside of the connector 2. A retractable protection device 5 is telescopically sleeved outside the optical fiber grating temperature measurement sleeve 4, and a fixed end of the retractable protection device 5 is connected to the locking nut 3. A multi-directional damping protection device is provided inside the retractable protection device, and the multi-directional damping protection device is provided with a plurality of hydraulic damping units 6 distributed circumferentially to elastically clamp the optical fiber grating temperature measurement sleeve 4.

[0060] Specifically, the retractable protection device 5 is used to control the telescopic movement of the fiber Bragg grating temperature measuring sleeve 4. During the non-working state, the fiber Bragg grating temperature measuring sleeve 4 retracts into the retractable protection device 5 and is protected by the multi-directional damping protection device. During operation, the fiber Bragg grating temperature measuring sleeve 4 extends out of the retractable protection device 5 to measure the temperature of the fluid in the heat transfer oil furnace. A femtosecond fiber Bragg grating temperature sensor is arranged inside the fiber Bragg grating temperature measuring sleeve 4. The temperature measuring device is intended to adopt a femtosecond fiber Bragg grating temperature sensing system, which can realize the measurement of multiple temperature points. Dozens of temperature measurement points can be arranged on a single sensor, and they can be connected in series at the points to be measured, enabling array-type multi-point linear temperature measurement.

[0061] Disadvantages of traditional electrical sensors: Parallel measurement, unable to be multiplexed; Single-point measurement occupies a large space; The system is complex; Low reliability; Complex wiring; Metals are prone to oxidation and corrosion and are vulnerable to electromagnetic field interference and cannot be measured under radiation; There are risks of explosion and fire due to electrification and electric sparks; Problems such as insulation.

[0062] Advantages of grating temperature sensors: Serial measurement; Multiplexed multi-point measurement, light and small, easy to deploy; Can be attached to the surface, implanted, or integrated; High mechanical strength; Long service life, immune to electromagnetic interference and radiation; Passive device, no electric sparks.

[0063] In the embodiment of the present invention, the retractable protection device 5 includes a retractable sleeve 51. The top end of the retractable sleeve 51 is fixedly connected to the bottom end of the locking nut 3. The bottom end of the retractable sleeve 51 is slidably connected to a fixed sleeve 52, and the retractable sleeve 51 is piston-connected inside the fixed sleeve 52. A driving seal cavity 53 is formed inside the fixed sleeve 52. The fixed sleeve 52 can be positioned in the area of the heating furnace where temperature needs to be measured by means of bolts or welding. An electric push rod 54 is installed on the fixed sleeve 52. The output shaft of the electric push rod 54 is connected to an annular air pressure plate 55. The volume of the driving seal cavity 53 changes according to the height of the annular air pressure plate 55. The annular air pressure plate 55 is piston-connected inside the fixed sleeve 52.

[0064] To solve the problem that the applicable temperature of the internal components of the temperature measurement system junction box 1 cannot be too high, a condensate bellows 56 is added. The condensate bellows 56 is fixedly connected between the end of the fixed sleeve 52 and the end of the retractable sleeve 51. Through heat exchange with the air, the temperature of the end is lower than the safe temperature of the temperature measurement element. An exhaust hole is provided on the fixed sleeve 52.

[0065] During non - working periods, the fiber - optic grating temperature - measuring sleeve 4 shrinks entirely inside the fixed sleeve 52. When it is necessary to use the fiber - optic grating temperature - measuring sleeve 4 to measure the temperature of the fluid in the heat - conducting oil heating furnace, according to the required measurement distance, the electric push rod 54 is started. The output shaft of the electric push rod 54 sucks and drives the gas in the sealed cavity 53 through the annular air - pressure plate 55. The negative pressure generated in the sealed cavity 53 drives the overall downward movement of the shrinkage sleeve 51. By controlling the movement distance of the output shaft of the electric push rod 54, the downward movement distance of the shrinkage sleeve 51 can be adjusted, enabling the entire fiber - optic grating temperature - measuring sleeve 4 to move downward together with the connector 2 and the locking nut 3. When moving downward, it achieves the effect of ejecting the fiber - optic grating temperature - measuring sleeve 4 in the fixed sleeve 52, realizing the effect of measuring the temperature of the fluid in the heat - conducting oil heating furnace. At the same time, the measurement position can be adjusted, improving the overall measurement applicability and practicality. And by controlling the shrinkage state of the fiber - optic grating temperature - measuring sleeve 4 in an electric - control manner, it can achieve the effect of freely switching between the working state and the non - working state, avoiding the inconvenience of the traditional manual - adjustment method of switching the working state by adjusting the connector 2.

[0066] Meanwhile, the added exhaust hole is used for ventilation and exhaust of the inside of the fixed sleeve 52 when the annular air - pressure plate 55 moves up and down.

[0067] Furthermore, the hydraulic damping unit 6 includes an oil - storage cavity 61 opened in the fixed sleeve 52 and a plurality of working cavities 62 distributed in a circular array. The inside of the oil - storage cavity 61 and the working cavities 62 is connected. The inside of the oil - storage cavity 61 is composed of a combination of hydraulic oil and compressed gas. In order to enable the multi - directional damping protection device to exert the best protection performance, no gas can enter the working cavities 62, and it must be ensured that there is always hydraulic oil filling. At this time, the oil - storage cavity 61 comes into play. The oil - storage cavity 61 stores sufficient hydraulic oil, the inside of the working cavities 62 is filled with hydraulic oil, and there is always hydraulic oil filling in the working cavities 62. The oil - storage cavity 61 is only in a semi - filled state, and the other spaces are filled with gas that can be compressed and will expand.

[0068] A total damping component 63 is arranged inside the oil - storage cavity 61, and an external - force - pressed damping component 64 is arranged inside the working cavity 62. A plug rod 65 is arranged on the external - force - pressed damping component 64, and a protective arc plate 66 is fixedly connected to the outer end of the plug rod 65. A plurality of protective arc plates 66 are distributed in a circular - array state outside the fiber - optic grating temperature - measuring sleeve 4.

[0069] When the plug rod 65 is pressed and moves outward towards the axis of the fixed sleeve 52, due to the influence of the pressure, the excess hydraulic oil will be squeezed into the oil storage cavity 61. When the plug rod 65 moves towards the axis of the fixed sleeve 52, the volume of the outer cavity of the working cavity 62 becomes larger, and the hydraulic oil in the oil storage cavity 61 will be drawn back. During the two processes of squeezing and drawing, both are affected by the damping forces of the external force pressing the damping component 64 and the total damping component 63. By using the throttling speed limit of each valve, shock absorption and buffering are achieved. Therefore, the two functions of shock absorption and buffering and preventing rebound can achieve the effect of fully protecting the surface of the fiber Bragg grating temperature measuring sleeve 4, thereby avoiding the problem that the fiber Bragg grating temperature measuring sleeve 4 is loosened and damaged due to the scouring vibration of the fluid during work. Inside the fixed sleeve 52, a guiding hopper 57 is fixedly connected. The guiding hopper 57 is used to guide the bottom end of the fiber Bragg grating temperature measuring sleeve 4 during installation, so that the fiber Bragg grating temperature measuring sleeve 4 can be located between the respective protective arc plates 66. One end of the protective arc plate 66 close to the guiding hopper 57 is provided with a chamfer to facilitate guiding when the fiber Bragg grating temperature measuring sleeve 4 is inserted.

[0070] The overall working principle of the multi-directional damping protection device is similar to that of the existing automobile shock absorber. Both use the damping force formed when each valve intercepts the flow to achieve the effects of shock absorption, buffering, and preventing rebound. The difference between the multi-directional damping protection device in this technical solution and the existing shock absorber is that it can maximize the protection of the object inside the hollow cylindrical device while reducing the occupied area, and can provide multi-directional protection for the cylindrical fiber Bragg grating temperature measuring sleeve 4, thereby avoiding the problem that the fiber Bragg grating temperature measuring sleeve 4 is loosened and damaged due to the scouring vibration of the fluid during work.

[0071] Furthermore, the external force pressing the damping component 64 includes a piston plate 641. The piston plate 641 is fixedly connected to the end of the plug rod 65. The active cavity on the side of the working cavity 62 close to the plug rod 65 and the piston plate 641 is set as the inner cavity, and the active cavity on the side of the working cavity 62 far from the plug rod 65 and the piston plate 641 is set as the outer cavity. A limiting valve seat 642 is fixedly connected to the side of the piston plate 641 close to the plug rod 65. A guide rod 643 is fixedly connected inside the limiting valve seat 642. A valve disc 644 is slidably connected to the guide rod 643. The guide rod 643 is used to limit the valve disc 644. A spring is fixedly connected between one end of the valve disc 644 and the inside of the limiting valve seat 642. A valve plate 645 is fixedly connected to the side of the piston plate 641 far from the plug rod 65 through a spring. The surfaces of the piston plate 641 and the valve plate 645 are piston-connected to the inner wall of the working cavity 62. The piston plate 641 is provided with a first valve hole 646 at the position of the valve disc 644. The valve plate 645 is provided with a second valve hole 647 at the position of the first valve hole 646. The piston plate 641 is provided with a third valve hole 648 that is misaligned with the first valve hole 646.

[0072] The scouring vibration of the fluid in the heat-conducting oil furnace causes the optical fiber grating temperature-measuring sleeve 4 to become loose. The loosening force acts on the protective arc plate 66. The protective arc plate 66 is pressed by the external force and drives the piston plate 641 as a whole to move outward from the axis of the fixed sleeve 52 through the plug rod 65. At this time, the valve disc 644 in the limit valve seat 642 opens, and the hydraulic oil flows into the oil storage cavity 61 successively through the first valve hole 646 and the second valve hole 647. Since the first valve hole 646 is relatively small, the hydraulic oil will be intercepted, and the upward flow rate will slow down. When the plug rod 65 starts to rebound, the pressure in the working cavity 62 slowly recovers. The plug rod 65 moves towards the axis of the fixed sleeve 52. Since the volume of the outer cavity increases, the oil pressure begins to decrease, and the hydraulic oil in the inner cavity will flow into the outer cavity synchronously. At this time, the valve plate 645 moves away from the piston plate 641 and opens the third valve hole 648. The first valve hole 646 is closed by the valve disc 644, and the hydraulic oil flows to the outer cavity successively from the second valve hole 647 and the third valve hole 648. This process is also controlled by interception, so a damping force will also be formed.

[0073] In addition, the total damping component 63 includes a fixed seat 631. The fixed seat 631 is fixedly connected inside the oil storage cavity 61. An arc-shaped valve seat 632 is elastically connected inside the fixed seat 631 through a spring. A flow-limiting valve 633 is connected to the arc-shaped valve seat 632. One end of the flow-limiting valve 633 away from the arc-shaped valve seat 632 is connected to a pressure valve 634. The end of the pressure valve 634 is elastically connected inside the oil storage cavity 61 through a spring. The end piston of the arc-shaped valve seat 632 is connected inside the fixed seat 631. The surface of the flow-limiting valve 633 is fixedly connected to the inside of the oil storage cavity 61. Grooves 637 and arc-shaped grooves 635 are respectively opened on the flow-limiting valve 633. A concave cavity 636 corresponding to the groove 637 is opened on the pressure valve 634.

[0074] When the plug rod 65 continues to be externally pressed, the oil pressure in the oil storage cavity 61 begins to rise. When the pressure is greater than the bearing value of the arc-shaped valve seat 632 and the spring thereon, the arc-shaped valve seat 632 will automatically open. At this time, the hydraulic oil will continue to flow upward in the oil storage cavity 61. In this process, both the valve disc 644 and the arc-shaped valve seat 632 perform throttling control on the hydraulic oil, thus forming a damping effect. When the plug rod 65 starts to rebound, the pressure in the working cavity 62 slowly recovers. The arc-shaped valve seat 632 on the fixed seat 631 will automatically close. When the plug rod 65 moves towards the axis of the fixed sleeve 52, since the volume of the outer cavity increases, the oil pressure begins to decrease, and the pressure valve 634 will automatically move downward and open in combination with the spring thereon. The hydraulic oil in the oil storage cavity 61 is drawn back through the arc-shaped groove 635 and the concave cavity 636.

[0075] Based on the same inventive concept, an embodiment of the present invention further provides a temperature measuring system for an electric heating furnace, including: an instruction receiving module, configured to receive and analyze the temperature measuring instruction of an operator; wherein, the temperature measuring instruction carries a target telescopic amount and a target damping coefficient; a control module, electrically connected to the instruction receiving module, configured to adjust the telescopic amount of the retractable protection device and the damping coefficient of the multi-directional damping protection device based on the target telescopic amount and the target damping coefficient in the temperature measuring instruction; an execution module, electrically connected to the control module, configured to start the retractable protection device to perform temperature measuring work after receiving the temperature measuring work information transmitted by the control module.

[0076] When the temperature measuring device and system of the embodiment of the present invention are in use, during the non-working period, the optical fiber grating temperature measuring sleeve 4 is integrally retracted inside the fixed sleeve 52. When it is necessary to use the optical fiber grating temperature measuring sleeve 4 to measure the temperature of the fluid in the heat transfer oil heating furnace, according to the distance to be measured, the electric push rod 54 is started. The output shaft of the electric push rod 54 sucks and drives the gas in the sealing cavity 53 through the annular air pressure plate 55, and the negative pressure generated by driving the sealing cavity 53 drives the whole retractable sleeve 51 to move downward. By controlling the distance of the output shaft movement of the electric push rod 54, the distance of the downward movement of the retractable sleeve 51 is adjusted, so that the whole optical fiber grating temperature measuring sleeve 4 can move downward together with the connector 2 and the locking nut 3. When moving downward, the effect of ejecting and measuring the temperature of the fluid in the heat transfer oil heating furnace inside the fixed sleeve 52 is achieved. At the same time, the measuring position can be adjusted, improving the overall measurement applicability and practicability. And by controlling the retraction state of the optical fiber grating temperature measuring sleeve 4 in an electric control manner, the effect of freely switching between the working state and the non-working state can be achieved, avoiding the inconvenience of the traditional manual adjustment of the connector 2 for the working state switching method.

[0077] In order to enable the multi-directional damping protection device to exert the best protection performance, no gas can enter the working cavity 62, and it must be ensured that there is always hydraulic oil filling. At this time, the oil storage cavity 61 comes into play. The oil storage cavity 61 stores enough hydraulic oil. When the plug rod 65 is pressed and moves outward from the axis of the fixed sleeve 52, affected by the pressure, the excess hydraulic oil will be squeezed into the oil storage cavity 61. When the plug rod 65 moves toward the axis of the fixed sleeve 52, the volume of the outer cavity of the working cavity 62 becomes larger, and the hydraulic oil in the oil storage cavity 61 will be sucked back again, and there is always hydraulic oil filling in the working cavity 62. During this process, the oil storage cavity 61 is only in a semi-filled state, and the other spaces are filled with gas that can be compressed and expanded.

[0078] Set the movable cavity on the side of the working cavity 62 close to the piston rod 65 and near the piston plate 641 as the inner cavity, and the movable cavity on the side of the working cavity 62 far from the piston rod 65 and away from the piston plate 641 as the outer cavity. When the fiber Bragg grating temperature measuring sleeve 4 is in the extended working state, the scouring vibration of the fluid in the heat-conducting oil heating furnace causes the fiber Bragg grating temperature measuring sleeve 4 to loosen. The loosening force acts on the protective arc plate 66. The protective arc plate 66 is pressed by the external force. The protective arc plate 66 drives the entire piston plate 641 to move outward from the axis of the fixed sleeve 52 through the piston rod 65. The scouring vibration of the fluid in the heat-conducting oil heating furnace causes the fiber Bragg grating temperature measuring sleeve 4 to loosen. The loosening force acts on the protective arc plate 66. The protective arc plate 66 is pressed by the external force. The protective arc plate 66 drives the entire piston plate 641 to move outward from the axis of the fixed sleeve 52 through the piston rod 65. At this time, the valve disc 644 in the limit valve seat 642 opens, and the hydraulic oil flows into the oil storage cavity 61 through the first valve hole 646 and the second valve hole 647 in sequence. Since the first valve hole 646 is relatively small, the hydraulic oil will be intercepted, and the upward flow rate will slow down. When the piston rod 65 continues to press outward, the oil pressure in the oil storage cavity 61 begins to rise. When the pressure is greater than the bearing value of the arc valve seat 632 and the spring thereon, the arc valve seat 632 will automatically open. At this time, the hydraulic oil will continue to flow upward in the oil storage cavity 61. During this process, both the valve disc 644 and the arc valve seat 632 perform throttling control on the hydraulic oil, forming a damping force on the pressure outside the axis of the fixed sleeve 52. Simply put, it is the throttling and speed limiting of the valve, achieving shock absorption and buffering.

[0079] When starting to rebound, the pressure in the working cavity 62 slowly recovers, and the arc valve seat 632 on the fixed seat 631 will automatically close. When the piston rod 65 moves toward the axis of the fixed sleeve 52, since the volume of the outer cavity becomes larger, the oil pressure begins to decrease, and the pressure valve 634 will automatically move downward and open in combination with the spring thereon. The hydraulic oil in the oil storage cavity 61 is drawn back through the arc-shaped groove 635 and the concave cavity 636. At the same time, the hydraulic oil in the inner cavity will flow into the outer cavity synchronously. At this time, the valve plate 645 is far from the piston plate 641 and opens the third valve hole 648. The first valve hole 646 is closed by the valve disc 644, and the hydraulic oil flows to the outer cavity through the second valve hole 647 and the third valve hole 648 in sequence. This process is also controlled by throttling, so a damping force will also be formed. Since both the external pressure and the rebound processes are affected by the damping force, the two functions of shock absorption and buffering and preventing rebound can achieve the effect of fully protecting the surface of the fiber Bragg grating temperature measuring sleeve 4, thereby avoiding the problem of loosening and damage of the fiber Bragg grating temperature measuring sleeve 4 caused by the scouring vibration of the fluid during work.

[0080] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A temperature measuring device for an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor, characterized in that: include: A junction box assembly, the junction box assembly comprising a junction box body and a connector which are rotatably connected to each other, a locking nut being threadedly connected to the end of the connector, a fiber Bragg grating temperature measuring sleeve extending to the interior of the heating furnace being fixedly connected to the end of the junction box body, and a femtosecond fiber Bragg grating temperature sensor being placed in the fiber Bragg grating temperature measuring sleeve; A retractable protective device, which can be telescopically sleeved on the outside of the fiber grating temperature measuring sleeve, and the fixed end of the retractable protective device is connected to a locking nut; A multi-directional damping protection device, which is arranged inside the retractable protection device and is provided with a plurality of hydraulic damping units distributed along the circumferential direction to elastically clamp the fiber grating temperature measuring sleeve; The retractable protective device comprises: An axially retractable shrink sleeve, one end of which is fixed to the end of the locking nut; A fixed sleeve sleeved on the shrink sleeve, the fixed sleeve and the end of the shrink sleeve form a piston-type connection; a driving sealing chamber is opened in the fixed sleeve, and an electric push rod and an annular air pressure plate connected to the output shaft of the electric push rod are installed on the fixed sleeve; The hydraulic damping unit comprises: An oil storage chamber and a working chamber, both of which are opened in the fixed sleeve, and the interiors of the oil storage chamber and the working chamber are communicated, the interior of the oil storage chamber is filled with hydraulic oil and compressed gas, and the interior of the working chamber is filled with hydraulic oil; A total damping assembly and an external force pressure damping assembly, wherein the total damping assembly is arranged in the oil storage chamber, the external force pressure damping assembly is arranged in the working chamber, and the external force pressure damping assembly is provided with a plug rod and a plurality of protective arc plates fixedly connected to the outer end of the plug rod, and the plurality of protective arc plates are distributed outside the fiber optic Bragg grating temperature measuring sleeve in a circular array.

2. The temperature measuring device according to claim 1, characterized in that: The annular air pressure plate piston is connected in the fixed sleeve, a condensation spring tube is fixedly connected between the end of the fixed sleeve and the end of the shrink sleeve, and an exhaust hole is opened on the fixed sleeve.

3. The temperature measuring device of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to claim 1, characterized in that: The external force compression damping component comprises: A piston plate, the piston plate being fixedly connected to the end of the plug rod; A limit valve seat, the limit valve seat is fixedly connected to a side of the piston plate close to the plug rod; A guide rod, the guide rod is fixedly connected to the limit valve seat; A valve disc, the valve disc is slidably connected to the guide rod, and a spring is fixedly connected between one end of the valve disc and the inside of the limit valve seat; A valve plate is elastically connected to a side of the piston plate away from the plug rod.

4. The temperature measuring device for an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to claim 3, characterized in that: The surfaces of the piston plate and the valve plate are connected to the inner wall of the working chamber by pistons; The piston plate is provided with a valve hole one at the valve disc, the valve plate is provided with a valve hole two at the valve hole one, and the piston plate is provided with a valve hole three which is offset from the valve hole one.

5. The electric heating furnace temperature measuring device based on a femtosecond fiber Bragg grating temperature sensor according to claim 1, characterized in that: The total damping assembly comprises: A fixing seat, the fixing seat being fixedly connected in the oil storage cavity; An arc-shaped valve seat, wherein the arc-shaped valve seat is elastically connected to the fixed seat; A flow limiting valve and a pressure valve, wherein the flow limiting valve is arranged on the arc-shaped valve seat, one end of the flow limiting valve away from the arc-shaped valve seat is connected to the pressure valve, and the end of the pressure valve is elastically connected to the oil storage cavity.

6. The temperature measuring device of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to claim 5, characterized in that: The end piston of the arc-shaped valve seat is connected in the fixed seat; The surface of the flow limiting valve is fixedly connected to the interior of the oil storage cavity. A groove and an arc groove are respectively provided on the flow limiting valve, and a concave cavity corresponding to the groove is provided on the pressure valve.

7. The temperature measuring device of an electric heating furnace based on a femtosecond fiber Bragg grating temperature sensor according to claim 1, characterized in that: A guide bucket is fixedly connected to the interior of the fixed sleeve, and a guide angle is formed at one end of the protective arc plate (66) close to the guide bucket (57).

8. An electric heating furnace temperature measurement system based on a femtosecond fiber Bragg grating temperature sensor, based on the electric heating furnace temperature measurement device based on a femtosecond fiber Bragg grating temperature sensor according to any one of claims 1 to 7, characterized in that: include: An instruction receiving module is used to receive and analyze the temperature measurement instruction of the operator; wherein the temperature measurement instruction carries the target expansion amount and the target damping coefficient; A control module, the control module being electrically connected to the instruction receiving module and being used for adjusting the telescopic amount of the retractable protection device and the damping coefficient of the multi-directional damping protection device based on the target telescopic amount and the target damping coefficient in the temperature measurement instruction; An execution module is electrically connected to the control module, and starts the retractable protective device to perform temperature measurement after receiving the temperature measurement work information transmitted by the control module.

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