A seismic-resistant platinum resistance thermometer for nuclear power plants

Abstract

The present invention relates to the technical field of platinum resistance thermometers, and more specifically, to a seismic-resistant platinum resistance thermometer for use in nuclear power plants. The thermometer comprises a temperature sensing element and a housing fixed to the upper end of the temperature sensing element, wherein a nut is threadedly connected to the surface of the temperature sensing element. The thermometer further comprises: a sealing mechanism arranged at the lower end of the nut and comprising a first curved plate; a clamping mechanism connected to the lower end of the first curved plate, wherein the clamping mechanism comprises an elastic clamping body, and the clamping body is in the shape of a hollow sphere; a first shock-absorbing mechanism arranged at the upper end of the first curved plate, wherein the first shock-absorbing mechanism comprises a second curved plate made of spring steel; and a second shock-absorbing mechanism wrapped around the outside of the temperature sensing element and comprising a bellows made of spring steel. The bellows serves as a core shock-absorbing element, and absorbs pipeline vibration through deformation of the corrugated structure, while providing a sealed temperature measurement space for the temperature sensing element. The thermometer innovatively integrates sealing and shock-absorbing functions to adapt to complex working conditions such as the main pump pipeline of a nuclear power plant.

Description

Technical Field

[0001] The invention relates to the technical field of platinum resistance thermometers, in particular to a shock-resistant platinum resistance thermometer for nuclear power plants. Background Art

[0002] With the continuous improvement of industrial automation, the application of thermal resistors (RTRs) in the industrial sector is becoming increasingly widespread. Simultaneously, demand for temperature measurement is increasing in industries such as pharmaceuticals, food, and environmental protection, driving the growth of the RTD market. According to market research reports, the global RTD market has exceeded US$1 billion and is showing steady growth. However, nuclear-grade RTDs still account for a large proportion of imports. Seismic-resistant platinum RTD thermometers for nuclear power plants are temperature measurement devices designed specifically for the extreme environments of nuclear power plants. Based on the temperature measurement principle of platinum resistance, they achieve precise temperature measurement by measuring the linear relationship between the resistance value of platinum metal and temperature.

[0003] In complex working conditions such as the main pump pipelines and reactor coolant systems of nuclear power plants, temperature measurement equipment for small-diameter pipelines must simultaneously cope with strong vibrations, high temperature differences, and high reliability requirements. Traditional platinum resistance thermometers have technical bottlenecks: although a lot of seismic design has been done on the seismic-resistant platinum resistance thermometers used in nuclear power plants, they still have short service life, difficult maintenance, complex measurement conditions, and poor seismic performance. When the main pump pipelines of nuclear power plants are in use, the turbulent movement of the fluid (such as water or steam) or the gas-liquid two-phase flow (such as steam-water mixture) in the pipelines can cause pressure pulsations, causing Vibration occurs when the vibration frequency generated by fluid flow is consistent with the natural frequency of the pipeline, which may cause resonance and aggravate the vibration amplitude. When the pump is started, shut down or operated under variable load, mechanical stress changes and fluid dynamic fluctuations will cause transient vibration. The existing technology of earthquake-resistant platinum resistance thermometers used in nuclear power plants is difficult to meet the use of various working environments. Vibration may cause deformation of platinum resistance temperature sensing elements and generate internal stress. Connectors (such as plastic cable ties) tend to harden and become brittle in high temperature environments, resulting in binding failure. In addition, long platinum resistance thermometers are difficult to measure the temperature of small-diameter pipelines. Summary of the Invention

[0004] In view of the problems in the prior art, the present invention provides a shock-resistant platinum resistance thermometer for use in nuclear power plants.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a seismic-resistant platinum resistance thermometer for nuclear power plants, comprising a temperature sensing element and a housing fixed to the upper end of the temperature sensing element, wherein a nut is threadedly connected to the surface of the temperature sensing element; and further comprising:

[0006] A sealing mechanism, provided at the lower end of the nut, comprising a first arc-shaped plate, for achieving sealed isolation of the detection environment;

[0007] A locking mechanism connected to the lower end of the first arc-shaped plate, the locking mechanism comprising an elastic locking body in the shape of a hollow sphere;

[0008] a first shock-absorbing mechanism disposed at the upper end of the first curved plate, the first shock-absorbing mechanism comprising a second curved plate made of spring steel, the engaging body cooperating with the first curved plate to form a clamping structure for the second curved plate, the engaging body, the first curved plate, and the second curved plate together forming a multi-stage buffer structure through elastic deformation;

[0009] The second shock absorbing mechanism is wrapped around the outside of the temperature sensing element and includes a bellows made of spring steel.

[0010] Preferably, a stopper is fixed to the lower end of the nut, and the stopper drives the sealing mechanism and the locking mechanism to be linked through axial displacement.

[0011] Preferably, the sealing mechanism includes:

[0012] a first spring, the upper end of which is fixedly connected to the stopper; and a first baffle, which is fixedly connected to the lower end of the first spring;

[0013] The first arc-shaped plate is fixedly connected to the lower end of the first baffle, and the dynamic sealing between the first arc-shaped plate and the second arc-shaped plate is achieved through the pre-tightening force of the first spring.

[0014] Preferably, the engaging body is slidably connected to the surface of the temperature sensing element; the second spring is fixedly connected to the lower end of the engaging body;

[0015] The second baffle is fixedly connected to the lower end of the second spring and is clamped with the second arc-shaped plate through elastic deformation of the clamping body.

[0016] Preferably, the second curved plate is tightly fitted to the first curved plate;

[0017] The sleeve is fixedly connected to one end of the second arc-shaped plate.

[0018] Preferably, the first shock absorbing mechanism further comprises:

[0019] a first flange, fixedly connected to the upper end of the sleeve;

[0020] The second flange is fixedly connected to the first flange via first bolts.

[0021] Preferably, the upper end of the bellows is fixedly connected to the sleeve; the lower end of the bellows is fixedly connected to a third flange, the lower end of the third flange is tightly fitted with a fourth flange, and the fourth flange is fixedly connected to the third flange by a second bolt.

[0022] Beneficial effects of the present invention:

[0023] The present invention describes a seismic-resistant platinum resistance thermometer for nuclear power plants. This system utilizes the synergistic action of a first spring and a second spring to create a bidirectional preloaded seal. Driven by the first spring, the first curved plate abuts against the upper surface of the second curved plate. The second spring then elastically engages the engaging body with the lower surface of the second curved plate, forming a bidirectional upper and lower clamping seal.

[0024] The invention relates to a seismic-resistant platinum resistance thermometer for a nuclear power plant. The invention has a second curved plate firmly connected to the inner wall of the sleeve at the upper end of the bellows. When the vibration of the pipeline passes through the bellows for the initial energy absorption and shock absorption, the vibration of the bellows will be transmitted to the second curved plate. The second curved plate absorbs energy through elastic deformation. The second curved plate further reduces the vibration transmitted by the bellows through deformation energy absorption. The second curved plate transmits the vibration to the first curved plate and the engaging body. The first curved plate and the engaging body are also made of spring steel. The first curved plate and the engaging body are also arc-shaped. The first curved plate and the engaging body can further absorb energy and shock by bending deformation. The first curved plate and the engaging body clamp the second curved plate, so that the temperature sensing element can be connected to the bellows. The temperature sensing element can also be quickly removed when not in use. At the same time, the first curved plate, the engaging body and the second curved plate are tightly fitted together to seal the detection pipeline and the environment inside the bellows.

[0025] The present invention describes a seismic-resistant platinum resistance thermometer for use in nuclear power plants, in which the engaging body, the first curved plate, and the second curved plate together form a multi-stage buffer structure through elastic deformation; the bellows serves as the core shock-absorbing element, which not only absorbs pipeline vibration through the deformation of the corrugated structure, but also provides a closed temperature measurement space for the temperature sensing element; the innovative integration of sealing and shock-absorbing functions makes it suitable for complex working conditions such as the main pump pipelines of nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Figure 1 A schematic diagram of the overall structure provided by the present invention;

[0028] Figure 2 It is a schematic diagram of the connection structure between the temperature sensing element and the housing;

[0029] Figure 3 Schematic diagram of the connection structure between the nut and the stopper;

[0030] Figure 4 It is a cross-sectional view of the overall structure;

[0031] Figure 5 Schematic diagram of the connection structure between the sleeve and the first flange;

[0032] Figure 6Schematic diagram of the connection structure between the engaging body and the second arc-shaped plate;

[0033] Figure 7 Schematic diagram of the connection structure between the second spring and the second baffle;

[0034] Figure 8 Schematic diagram of the connection structure between the first baffle and the first arc-shaped plate.

[0035] In the figure: 100, temperature sensing element; 200, housing; 300, nut; 301, stopper; 400, sealing mechanism; 401, first spring; 402, first baffle; 403, first curved plate; 500, locking mechanism; 501, locking body; 502, second spring; 503, second baffle; 600, first shock-absorbing mechanism; 601, second curved plate; 602, sleeve; 603, first flange; 604, second flange; 605, first bolt; 700, second shock-absorbing mechanism; 701, bellows; 702, third flange; 703, fourth flange; 704, second bolt. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0037] like Figures 1-8 As shown, the present invention provides a seismic-resistant platinum resistance thermometer for nuclear power plants, comprising a temperature sensing element 100, the upper end of which is fixedly connected to the housing 200, and a nut 300 is connected to the surface of the temperature sensing element 100 through a threaded structure; a sealing mechanism 400, arranged at the lower end of the nut 300, comprising a first curved plate 403, for achieving sealed isolation of the detection environment; a snap-fit ​​mechanism 500, connected to the lower end of the first curved plate 403, comprising an elastic snap-fit ​​body 501, the snap-fit ​​body 501 being in the shape of a hollow sphere; a first shock-absorbing mechanism 600, arranged at the upper end of the first curved plate 403, comprising a second curved plate 601 made of spring steel, the snap-fit ​​body 501 cooperating with the first curved plate 403 to form a second shock-absorbing mechanism 600. The clamping structure of the two curved plates 601 is used to establish a reliable connection with the temperature measuring pipe. The engaging body 501, the first curved plate 403 and the second curved plate 601 together constitute a multi-stage buffer structure through elastic deformation; the second shock-absorbing mechanism 700 is wrapped around the outside of the temperature sensing element 100, and includes a bellows 701 made of spring steel, the lower end of which is connected to the temperature measuring pipe; the engaging body 501, the first curved plate 403 and the second curved plate 601 together constitute a multi-stage buffer structure through elastic deformation; the bellows 701 serves as the core shock-absorbing element, which not only absorbs pipeline vibration through the deformation of the corrugated structure, but also provides a closed temperature measurement space for the temperature sensing element 100; it innovatively integrates sealing and shock-absorbing functions to adapt to complex working conditions such as the main pump pipeline of a nuclear power plant.

[0038] Specifically, a stopper 301 is fixedly connected to the lower end of the nut 300 , and the stopper 301 drives the sealing mechanism 400 and the engaging mechanism 500 to be linked by axial displacement.

[0039] The sealing mechanism 400 also includes a first spring 401, the upper end of which is fixedly connected to the stopper 301; a first baffle 402, fixedly connected to the lower end of the first spring 401; and a first curved plate 403, fixedly connected to the lower end of the first baffle 402. The preload of the first spring 401 provides a dynamic seal between the first curved plate 403 and the second curved plate 601. The temperature sensing element 100 is inserted into the bellows 701, and its downward movement simultaneously drives the stopper 301 downward. The downward movement of the stopper 301 is driven by a transmission chain formed by the first spring 401 and the first baffle 402, ultimately driving the first curved plate 403 downward to contact the upper surface of the second curved plate 601. Both the first curved plate 403 and the second curved plate 601 are made of spring steel.

[0040] Furthermore, the locking mechanism 500 includes: a locking body 501, which is slidably connected to the temperature sensing element 100; a second spring 502, which is fixedly connected to the lower end of the locking body 501; a second baffle 503, which is fixedly connected to the lower end of the second spring 502, and is locked with the second curved plate 601 through elastic deformation of the locking body 501; the downward displacement of the temperature sensing element 100 drives the second spring 502 to move downward through the second baffle 503, and the downward displacement of the second spring 502 drives the locking body 501 to move downward. The diameter of the locking body 501 is larger than the inner circle diameter of the second curved plate 601. At this time, when the locking body 501 contacts the second curved plate 601, it will cause the locking body 501 to produce elastic deformation. When the engaging body 501 contacts the second curved plate 601, its deformation characteristics make it slide to the bottom of the second curved plate 601, forming an upper and lower bidirectional clamping structure: the first curved plate 403 is tightly attached to the upper surface of the second curved plate 601, and the engaging body 501 is elastically clamped to the lower surface of the second curved plate 601. The first curved plate 403 and the engaging body 501 cooperate to clamp the second curved plate 601. At the same time, the first curved plate 403, the engaging body 501 and the second curved plate 601 play a role in measuring the temperature environment and Sealing effect, at the same time, the arrangement of the first curved plate 403, the engaging body 501, and the second curved plate 601 can also play a multiple buffering and shock absorbing role, the first spring 401 always drives the first curved plate 403 to fit on the upper surface of the second curved plate 601 under the action of elastic force, and the second spring 502 always drives the engaging body 501 to fit on the lower surface of the second curved plate 601 under the action of elastic force, and the arrangement of the first spring 401 and the second spring 502 can further improve the absorption of axial vibration.

[0041] It should be noted that the first shock-absorbing mechanism 600 includes: a second curved plate 601, which fits tightly with the first curved plate 403; a sleeve 602, which is fixedly connected to one end of the second curved plate 601; a first flange 603, which is fixedly connected to the upper end of the sleeve 602; a second flange 604, which is fixedly connected to the first flange 603 through a first bolt 605; the axial preload force generated by the rotating nut 300 drives the stop block 301 to drive the first spring 401 to be continuously compressed, so that the first curved plate 403 and the engaging body 501 form a rigid clamp. This structure achieves multiple technical effects: the second curved plate 601 is flange-connected to the external bracket, and the sleeve 602 is fixed to the external bracket through the first flange 603, the second flange 604 and the first bolt 605 to establish a mechanical connection, thereby fixing the upper end of the bellows 701 or not; the contact surface between the first curved plate 403 and the second curved plate 601 forms a radial seal; the first curved plate 403 made of spring steel, the engaging body 501 and the second curved plate 601 constitute a multi-stage elastic buffer system.

[0042] It is worth mentioning that the second shock-absorbing mechanism 700 includes: a bellows 701, the upper end of which is fixedly connected to the sleeve 602; a third flange 702, fixedly connected to the lower end of the bellows 701; a fourth flange 703, fixedly connected to the third flange 702 via a second bolt 704, forming a temperature measurement pipe connection interface; the bellows 701 serves as the core shock-absorbing element. The bellows 701 is made of spring steel and has a certain degree of elasticity. Its lower end is connected to the temperature measurement pipe bellows 701 via the third flange 702, the fourth flange 703, and the second bolt 704. The upper end of the bellows 701 forms an integrated shock-absorbing structure with the first shock-absorbing mechanism 600 via the second curved plate 601. This design enables the bellows 701 to not only provide a temperature measurement space for the temperature sensing element 100, but also absorb pipeline vibration energy through the axial / radial deformation of the corrugated structure, making it particularly suitable for seismic temperature measurement scenarios of small-diameter pipelines.

[0043] Working Principle: During use, the temperature sensing element 100 is inserted into the bellows 701. The downward movement of the temperature sensing element 100 simultaneously drives the stopper 301 downward. The downward movement of the stopper 301 forms a transmission chain through the first spring 401 and the first baffle 402, ultimately driving the first curved plate 403 downward to fit against the upper surface of the second curved plate 601. The first and second curved plates 403 and 601 are made of spring steel.

[0044] At the same time, the downward displacement of the temperature sensing element 100 drives the second spring 502 to move downward through the second baffle 503, and the downward displacement of the second spring 502 drives the engaging body 501 to move downward. The diameter of the engaging body 501 is larger than the inner diameter of the second curved plate 601. At this time, when the engaging body 501 contacts the second curved plate 601, it causes the engaging body 501 to produce elastic deformation. When the engaging body 501 contacts the second curved plate 601, its deformation characteristics cause it to slide below the second curved plate 601, forming an upper and lower bidirectional clamping structure: the first curved plate 403 is tightly attached to the upper surface of the second curved plate 601, and the engaging body 501 is elastically clamped to the lower surface of the second curved plate 601. The first curved plate 403 and the engaging body 501 cooperate to clamp the second curved plate 601. At the same time, the first curved plate 403, the engaging body 501 and the second curved plate 601 play a role in measuring the temperature environment and Sealing effect, at the same time, the arrangement of the first curved plate 403, the engaging body 501, and the second curved plate 601 can also play a multiple buffering and shock absorbing role, the first spring 401 always drives the first curved plate 403 to fit on the upper surface of the second curved plate 601 under the action of elastic force, and the second spring 502 always drives the engaging body 501 to fit on the lower surface of the second curved plate 601 under the action of elastic force, and the arrangement of the first spring 401 and the second spring 502 can further improve the absorption of axial vibration.

[0045] The axial preload generated by rotating the nut 300 drives the stopper 301 to continuously compress the first spring 401, thereby rigidly clamping the first curved plate 403 and the engaging body 501. This structure achieves multiple technical effects: through the flange connection of the second curved plate 601 to the external bracket, the sleeve 602 is fixed to the external bracket via the first flange 603, the second flange 604, and the first bolt 605 to establish a mechanical connection, thereby fixing the upper end of the bellows 701 or not; the contact surface of the first curved plate 403 and the second curved plate 601 forms a radial seal; the first curved plate 403, the engaging body 501, and the second curved plate 601 made of spring steel form a multi-stage elastic buffer system.

[0046] The bellows 701 serves as the core damping element. Made of spring steel and possessing a certain degree of elasticity, its lower end is connected to the temperature measurement pipe via a third flange 702, a fourth flange 703, and a second bolt 704. The upper end of the bellows 701 forms an integral damping structure with the first damping mechanism 600 via a second curved plate 601. This design allows the bellows 701 to both provide temperature measurement space for the temperature sensing element 100 and absorb pipeline vibration energy through axial and radial deformation of the corrugated structure, making it particularly suitable for seismic temperature measurement applications on small-diameter pipes. When the bellows is subjected to vibration, the corrugated structure of the spring steel allows for axial, lateral, and angular deformation, converting kinetic energy into elastic potential energy. The high elastic modulus ensures rapid recovery after deformation, avoiding permanent set. During vibration, grain boundary sliding and dislocation motion within the spring steel generate damping forces, releasing some of the energy as heat, reducing the transmission of vibration energy to the connected equipment. The spring steel's high damping coefficient allows for the conversion of vibration energy into heat through internal friction. This energy dissipation mechanism can significantly reduce the resonance amplitude and shorten the vibration duration. The corrugated structure of the bellows allows it to deform in three directions: axial, lateral, and angular, fully absorbing complex vibrations. The bellows made of spring steel achieves effective absorption and dissipation of vibrations through the synergy of high elastic material properties and optimized structural design.

[0047] The second curved plate 601 is connected to the upper end of the bellows 701 through the sleeve 602. When the vibration of the pipeline passes through the bellows 701 for the initial energy absorption and shock reduction, the vibration of the bellows 701 will be transmitted to the second curved plate 601. The second curved plate 601 absorbs energy through elastic deformation. The second curved plate 601 absorbs energy through deformation and further reduces the vibration transmitted by the bellows 701. The second curved plate 601 transmits the vibration to the first curved plate 403 and the engaging body 501. The first curved plate 403 and the engaging body 501 are also made of spring steel. The first curved plate 403 and the engaging body 501 are also arc-shaped. The first curved plate 403 and the engaging body 501 can further absorb energy and reduce shock by bending deformation. The first curved plate 403 and the engaging body 501 clamp the second curved plate 601, so that the temperature sensing element 100 can be connected to the bellows 701. Then, the temperature sensing element 100 can be quickly taken out when not in use. At the same time, the first curved plate 403, the engaging body 501 and the second curved plate 601 fit tightly together, and the environment inside the detection pipeline and the bellows 701 can be sealed. At the same time, the surfaces of the first curved plate 403 and the engaging body 501 are elastically connected with the first spring 401 and the second spring 502 respectively. The first spring 401 and the second spring 502 can further absorb vibration through deformation. At the same time, the first spring 401 and the second spring 502 can also drive the first curved plate 403, the engaging body 501 and the second curved plate 601 to fit more closely, so that the first spring 401 and the second spring 502 promote the first curved plate 403, the engaging body 501 and the second curved plate 601 to be better sealed, so that the detection environment inside the bellows 701 and the main pump pipeline of the nuclear power plant is more accurate.

[0048] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A seismic-resistant platinum resistance thermometer for use in a nuclear power plant, comprising a temperature sensing element (100) and a housing (200) fixed to the upper end of the temperature sensing element (100), characterized in that: The surface of the temperature sensing element (100) is threadedly connected with a nut (300); and further comprising: A sealing mechanism (400) is provided at the lower end of the nut (300), comprising a first arc-shaped plate (403) for achieving sealed isolation of the detection environment; A snap-fit ​​mechanism (500) is connected to the lower end of the first arc-shaped plate (403), wherein the snap-fit ​​mechanism (500) comprises an elastic snap-fit ​​body (501), and the snap-fit ​​body (501) is in the shape of a hollow sphere; A first shock absorbing mechanism (600) is provided at the upper end of the first curved plate (403), the first shock absorbing mechanism (600) comprising a second curved plate (601) made of spring steel, the engaging body (501) cooperates with the first curved plate (403) to form a clamping structure for the second curved plate (601), and the engaging body (501), the first curved plate (403) and the second curved plate (601) together form a multi-stage buffer structure through elastic deformation; The second shock absorbing mechanism (700) is wrapped around the outside of the temperature sensing element (100) and includes a bellows (701) made of spring steel.

2. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 1, characterized in that: A stopper (301) is fixed to the lower end of the nut (300), and the stopper (301) drives the sealing mechanism (400) and the engaging mechanism (500) to move in an axial direction.

3. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 2, characterized in that: The sealing mechanism (400) comprises: a first spring (401), the upper end of the first spring (401) being fixedly connected to the stopper (301); and a first baffle (402), being fixedly connected to the lower end of the first spring (401); The first curved plate (403) is fixedly connected to the lower end of the first baffle (402), and a dynamic seal between the first curved plate (403) and the second curved plate (601) is achieved through the pre-tightening force of the first spring (401).

4. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 1, characterized in that: The engaging body (501) is slidably connected to the surface of the temperature sensing element (100); a second spring (502) is fixedly connected to the lower end of the engaging body (501); The second baffle (503) is fixedly connected to the lower end of the second spring (502) and is engaged with the second arc-shaped plate (601) through elastic deformation of the engaging body (501).

5. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 3, characterized in that: The second curved plate (601) is tightly fitted to the first curved plate (403); The sleeve (602) is fixedly connected to one end of the second arc-shaped plate (601).

6. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 5, characterized in that: The first shock absorbing mechanism (600) further comprises: A first flange (603) is fixedly connected to the upper end of the sleeve (602); The second flange (604) is fixedly connected to the first flange (603) via a first bolt (605).

7. The seismic-resistant platinum resistance thermometer for nuclear power plants according to claim 6, characterized in that: The upper end of the bellows (701) is fixedly connected to the sleeve (602); the lower end of the bellows (701) is fixedly connected to a third flange (702), the lower end of the third flange (702) is tightly fitted with a fourth flange (703), and the fourth flange (703) is fixedly connected to the third flange (702) by a second bolt (704).

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