Method and system for detecting thrust of valve rod of valve and intelligent valve rod

Abstract

The invention provides a valve rod thrust detection method and system and an intelligent valve rod. At least one fiber bragg grating thrust sensor is fixed on the surface of the valve rod in the axial direction of the valve rod, the central wavelength of the at least one fiber bragg grating thrust sensor changes based on the axial strain of the valve rod, and a tail fiber of the at least one fiber bragg grating thrust sensor is connected with a fiber bragg grating demodulator. The fiber bragg grating demodulator is used for collecting a first central wavelength of the at least one fiber bragg grating thrust sensor; the method comprises the steps that thrust is output to the valve rod through an actuator, and the valve rod is driven to act; when the valve rod acts, acquiring a first central wavelength of the at least one fiber bragg grating thrust sensor acquired by a fiber bragg grating demodulator; and based on the relation between the offset of the first central wavelength and the thrust, the thrust borne by the valve rod is determined according to the obtained first central wavelength. According to the scheme, the thrust of the valve rod can be automatically detected.

Description

Technical Field

[0001] The present application relates to the field of valve detection technology, and in particular to a valve stem thrust detection method and system, and an intelligent valve stem. Background Art

[0002] In the energy and chemical industry, especially in the field of nuclear power, valves are key components of control pipelines, and their operating status is crucial. Once a valve is stuck or has other faults, it will cause huge economic losses or even casualties. Therefore, it is necessary to monitor the operating status of the valve to ensure continuous and reliable operation of the valve.

[0003] Among the many operating parameters of the valve, valve stem thrust is an important indicator. Currently, there is a lack of means to automatically detect the valve stem thrust. How to achieve automatic detection of valve stem thrust is a technical problem that urgently needs to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a valve stem thrust detection method, system and intelligent valve stem, so as to achieve the effect of automatically detecting the valve stem thrust.

[0005] According to one aspect of the present application, a valve stem thrust detection method is provided, wherein at least one fiber Bragg grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem, the central wavelength of the at least one fiber Bragg grating thrust sensor changes based on the axial strain of the valve stem, the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect a first central wavelength of the at least one fiber Bragg grating thrust sensor; the method comprises:

[0006] Outputting thrust to the valve stem through an actuator to drive the valve stem to move;

[0007] When the valve stem moves, obtaining a first central wavelength of the at least one fiber Bragg grating thrust sensor collected by a fiber Bragg grating demodulator;

[0008] The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength.

[0009] In one embodiment, a fiber Bragg grating temperature sensor is also fixed on the surface of the valve stem, and the fiber Bragg grating temperature sensor and the at least one fiber Bragg grating thrust sensor are in the same temperature field; the pigtail of the fiber Bragg grating temperature sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect the second central wavelength of the fiber Bragg grating temperature sensor; the method further comprises: when the valve stem moves, obtaining the second central wavelength of the fiber Bragg grating temperature sensor collected by the fiber Bragg grating demodulator;

[0010] The determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength includes:

[0011] The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength.

[0012] In one embodiment, two fiber Bragg grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber Bragg grating thrust sensors are symmetrically fixed on the surfaces of both sides of the valve stem;

[0013] The step of acquiring the first central wavelength of the at least one fiber Bragg grating thrust sensor acquired by the fiber Bragg grating demodulator comprises:

[0014] Respectively acquiring the first central wavelengths of the two fiber Bragg grating thrust sensors collected by the fiber Bragg grating demodulator;

[0015] Determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength includes:

[0016] Determine the thrust exerted on the valve stem based on the acquired first central wavelength of each fiber Bragg grating thrust sensor and the relationship between the offset of the first central wavelength and the thrust;

[0017] The average of the two determined thrusts is determined as the thrust exerted on the valve stem.

[0018] In one embodiment, two fiber Bragg grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber Bragg grating thrust sensors are symmetrically fixed on the surfaces of both sides of the valve stem;

[0019] The step of acquiring the first central wavelength of the at least one fiber Bragg grating thrust sensor acquired by the fiber Bragg grating demodulator comprises:

[0020] Respectively acquiring the first central wavelengths of the two fiber Bragg grating thrust sensors collected by the fiber Bragg grating demodulator;

[0021] The method of determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength, comprises:

[0022] Determine the thrust exerted on the valve stem based on the first central wavelength and the second central wavelength of each fiber Bragg grating thrust sensor, and the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust;

[0023] The average of the two determined thrusts is determined as the thrust exerted on the valve stem.

[0024] According to a second aspect of the present application, a valve stem thrust detection system is provided, comprising a valve stem, a fiber grating demodulator and a host computer;

[0025] At least one fiber Bragg grating thrust sensor is fixed on the surface of the valve stem along the axial direction of the valve stem, the central wavelength of the at least one fiber Bragg grating thrust sensor changes based on the axial strain of the valve stem, and the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator;

[0026] The valve stem is used to act according to the output thrust of the actuator;

[0027] The fiber Bragg grating demodulator is used to collect the first central wavelength of the at least one fiber Bragg grating thrust sensor;

[0028] The host computer is used to obtain the first central wavelength of the at least one fiber Bragg grating thrust sensor collected by the fiber Bragg grating demodulator when the valve stem moves;

[0029] The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength.

[0030] In one embodiment, the valve stem surface includes at least one uniformly stressed section, and a fiber grating thrust sensor is fixed to any uniformly stressed section.

[0031] In one embodiment, the valve stem surface includes two evenly stressed sections, and the two evenly stressed sections are symmetrically located on the surfaces of both sides of the valve stem along the axial direction of the valve stem.

[0032] In one embodiment, the at least one fiber grating thrust sensor is fixed to the surface of the valve stem by welding or gluing.

[0033] In one embodiment, the valve stem further includes at least one metal protective shell, wherein any metal protective shell is connected to the valve stem by welding and covers a uniformly stressed section to protect the fiber grating thrust sensor.

[0034] In one embodiment, the fiber Bragg grating thrust sensor is a fiber Bragg grating thrust sensor using a full metal package.

[0035] In one embodiment, a fiber Bragg grating temperature sensor is also fixed on the valve stem surface, and the fiber Bragg grating temperature sensor and the at least one fiber Bragg grating thrust sensor are in the same temperature field; the pigtail of the fiber Bragg grating temperature sensor is connected to a fiber Bragg grating demodulator.

[0036] According to a third aspect of the present application, a smart valve stem is provided, wherein the smart valve stem is the valve stem in any embodiment of the second aspect.

[0037] By adopting the valve stem thrust detection method, system and intelligent valve stem proposed in the present application, at least one fiber grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem, and the central wavelength of the fiber grating thrust sensor changes based on the axial strain of the valve stem. When the valve stem moves based on the thrust, the host computer obtains the first central wavelength of the fiber grating thrust sensor collected by the fiber grating demodulator, and can quickly and accurately automatically detect the thrust exerted on the valve stem based on the first central wavelength and the relationship between the predetermined offset of the first central wavelength and the thrust. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic structural diagram of a valve stem thrust detection system provided for one embodiment of the present application.

[0039] Figure 2 A schematic diagram of the structure of an intelligent valve stem provided in one embodiment of the present application;

[0040] Figure 3 A schematic structural diagram of another valve stem thrust detection system provided in one embodiment of the present application;

[0041] Figure 4 A schematic flow chart of a valve stem thrust detection method provided for one embodiment of the present application;

[0042] Figure 5 A diagram showing the change of valve stem thrust with stroke measured by a fiber Bragg grating thrust sensor during the opening process of an electric gate valve provided by an embodiment of the present application;

[0043] Figure 6 A diagram showing the change of valve stem thrust with stroke measured by a fiber Bragg grating thrust sensor during the closing process of an electric gate valve provided by one embodiment of the present application;

[0044] Figure 7 A diagram showing the change of valve stem thrust with stroke measured by a fiber grating thrust sensor during the opening process of an unloaded electric gate valve provided by one embodiment of the present application;

[0045] Figure 8 A diagram showing the change in valve stem thrust versus stroke measured by a fiber grating thrust sensor during the closing process of an unloaded electric gate valve provided in one embodiment of the present application. DETAILED DESCRIPTION

[0046] Before introducing the embodiments of the present application, it should be noted that:

[0047] Some embodiments of the present application are described as processing flows. Although the various operation steps of the flow may be given sequential step numbers, the operation steps therein may be implemented in parallel, concurrently or simultaneously.

[0048] In the embodiments of the present application, the terms "first", "second", etc. may be used to describe various features, but these features should not be limited by these terms. These terms are used only to distinguish one feature from another.

[0049] The term “and / or” may be used in the embodiments of the present application. “And / or” includes any and all combinations of one or more of the listed associated features.

[0050] It should be understood that when describing the connection or communication relationship between two components, unless it is explicitly stated that the two components are directly connected or directly communicating, the connection or communication between the two components can be understood as direct connection or communication, or as indirect connection or communication through an intermediate component.

[0051] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0052] In the energy and chemical industry, especially in the field of nuclear power, valves are key components of control pipelines, and their operating status is crucial. Once a valve is stuck or has other faults, it will cause huge economic losses or even casualties. Therefore, it is necessary to monitor the operating status of the valve to ensure continuous and reliable operation of the valve.

[0053] Among the many operating parameters of the valve, valve stem thrust is an important indicator. Currently, there is a lack of means to automatically detect the valve stem thrust. How to achieve automatic detection of valve stem thrust is a technical problem that urgently needs to be solved.

[0054] Based on the above problems, Figure 1 As shown, the present application proposes a valve stem thrust detection system, which includes a valve, a fiber grating demodulator and a host computer. The valve can be a straight-stroke valve, such as a gate valve. The valve includes a valve stem, such as Figure 1 As shown, at least one fiber Bragg grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem. It can be understood that although Figure 1The valve stem schematically includes only one fiber Bragg thrust sensor, but the present application does not limit the number of fiber Bragg thrust sensors on the valve stem, and there may also be multiple fiber Bragg thrust sensors. The fiber Bragg sensor is based on the sensing process of fiber Bragg, which obtains sensing information by modulating the fiber Bragg wavelength by external physical parameters, and is a wavelength modulated fiber sensor. In the present application, since the fiber Bragg thrust sensor is fixed in the axial direction of the valve stem, when the valve stem is subjected to axial thrust and generates strain, the center wavelength of the fiber Bragg thrust sensor will also change accordingly. That is, the center wavelength of at least one fiber Bragg thrust sensor fixed on the valve stem will change based on the axial strain of the valve stem.

[0055] As shown in FIG1 , the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator.

[0056] The valve is connected to the actuator, and the valve stem in the valve is used to move according to the thrust output by the actuator.

[0057] Since the fiber grating demodulator is connected to the pigtail of at least one fiber grating thrust sensor on the valve stem, the fiber grating demodulator can be used to collect the first central wavelength of the at least one fiber grating thrust sensor;

[0058] The host computer is used to obtain the first central wavelength of the at least one fiber grating thrust sensor collected by the fiber grating demodulator when the valve stem moves, and determine the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the obtained first central wavelength.

[0059] For the convenience of explanation, in this application, the central wavelength of the fiber Bragg grating thrust sensor is referred to as the first wavelength, and the central wavelength of the fiber Bragg grating temperature sensor is referred to as the second wavelength. The offset of the first wavelength is the difference between the central wavelength of the fiber Bragg grating thrust sensor when the valve stem is subjected to thrust and the central wavelength of the fiber Bragg grating thrust sensor when the valve stem is not subjected to force.

[0060] In a specific implementation, if the elastic modulus of the valve stem material and the strain sensitivity of the fiber Bragg grating thrust sensor are calibrated in advance, the host computer can determine the thrust of the valve stem according to the following formula (1) based on the relationship between the offset of the first center wavelength and the thrust and the acquired first center wavelength:

[0061]

[0062] Where: F is the valve stem thrust; E is the elastic modulus of the valve stem material; D is the diameter of the valve stem; is the central wavelength of the fiber Bragg grating thrust sensor when the valve stem is not under stress; This the central wavelength of the fiber Bragg grating thrust sensor when the valve is subjected to thrust action; is the offset of the first central wavelength; is the strain sensitivity of the fiber Bragg grating thrust sensor.

[0063] In another specific implementation, if the valve stem on which the fiber Bragg grating thrust sensor is installed is used as a calibration object in advance, and the force sensitivity of the fiber Bragg grating thrust sensor installed on the valve stem is calibrated, then the host computer can determine the thrust exerted on the valve stem according to the following formula (2) based on the relationship between the offset of the first central wavelength and the thrust and the first central wavelength obtained:

[0064]

[0065] Where, F is the valve stem thrust; K F To obtain the force sensitivity of the fiber Bragg grating thrust sensor installed on the valve stem by calibration; is the central wavelength of the fiber Bragg grating thruster when the valve stem is not stressed; Th is the central wavelength of the fiber Bragg grating thruster when the valve is in motion, that is is the offset of the first central wavelength.

[0066] As mentioned above, at least one fiber grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem. Figure 1 The above descriptions are all based on a fiber Bragg grating thrust sensor as an example. The following description is based on two fiber Bragg grating thrust sensors fixed on the valve stem surface along the axial direction of the valve stem. Figure 2 As shown, two fiber grating thrust sensors FBG1 and FBG2 are symmetrically fixed on the surfaces on both sides of the valve stem. The two fiber grating thrust sensors are symmetrically fixed on the surfaces on both sides of the valve stem along the axial direction of the valve stem, which can ensure that the valve stem is uniformly stressed on the one hand, and can make the detected thrust more accurate on the other hand. In this embodiment, the host computer can specifically obtain the first center wavelengths of the two fiber grating thrust sensors collected by the fiber grating demodulator, and then determine the thrust received by the valve stem based on the first center wavelength of each fiber grating thrust sensor obtained and the relationship between the offset of the first center wavelength and the thrust; the average of the two determined thrusts is determined as the thrust received by the valve stem.

[0067] For example, if the force sensitivity of the fiber Bragg grating thrust sensor installed on the valve stem is calibrated in advance with the valve stem equipped with the fiber Bragg grating thrust sensor as the calibration object, the host computer can determine the thrust of the valve stem according to the following formula (2) for each first center wavelength obtained based on the relationship between the offset of the first center wavelength and the thrust:

[0068]

[0069] For example, the thrust F1 is obtained according to the first central wavelength of FBG1, and the thrust F2 is obtained according to the first central wavelength of FBG2. Then, the thrust acting on the valve stem is finally determined to be the average of F1 and F2.

[0070] Considering that in some cases, the temperature environment of the valve stem will change when it receives thrust, in order to eliminate the influence of temperature on the central wavelength of the grating fiber sensor, such as Figure 3 As shown, the present application proposes that a fiber Bragg grating temperature sensor is also fixed on the valve stem surface, and the fiber Bragg grating temperature sensor and the at least one fiber Bragg grating thrust sensor are in the same temperature field, such as fixing the fiber Bragg grating temperature sensor at an adjacent position to the at least one fiber Bragg grating thrust sensor to ensure that they are in the same temperature field, and the central wavelength of the fiber Bragg grating temperature sensor changes based on the temperature of the valve stem, and the pigtail of the fiber Bragg grating temperature sensor is also connected to the fiber Bragg grating demodulator.

[0071] The fiber grating demodulator is also used to collect the second central wavelength of the fiber grating temperature sensor.

[0072] The host computer is also used to obtain the second central wavelength of the fiber Bragg grating temperature sensor collected by the fiber Bragg grating demodulator when the valve stem moves;

[0073] The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength.

[0074] Specifically, if the elastic modulus of the valve stem material, the strain sensitivity of the fiber Bragg grating thrust sensor, the temperature coefficient of the fiber Bragg grating thrust sensor, and the temperature sensitivity of the fiber Bragg grating temperature sensor are calibrated in advance, the host computer can determine the thrust of the valve stem according to the following formula (3) based on the relationship between the offset of the first center wavelength, the offset of the second center wavelength and the thrust, and the acquired first center wavelength and second center wavelength:

[0075]

[0076] Among them, λ Th is the central wavelength of the fiber Bragg grating thrust sensor when the valve is in motion; is the central wavelength of the fiber Bragg grating thrust sensor when the valve stem is not stressed and at T0 temperature; T is the temperature when the valve is actuated, and T0 is the initial temperature when the valve stem is not stressed; is the temperature coefficient of the fiber Bragg grating thrust sensor; is the strain sensitivity of the fiber Bragg grating thrust sensor at the valve operating temperature T.

[0077] Where T is obtained according to the following formula (4):

[0078]

[0079] Where: T is the temperature when the valve is in action; T0 is the initial temperature when the valve stem is not under stress; is the temperature sensitivity of the fiber Bragg grating temperature sensor; is the central wavelength of the fiber Bragg grating temperature sensor at T0 temperature when the valve stem is not stressed; T It is the central wavelength of the fiber Bragg grating temperature sensor when the valve is in action.

[0080] In another specific implementation, if the force sensitivity of the fiber Bragg grating thrust sensor installed on the valve stem is calibrated in advance with the valve stem equipped with the fiber Bragg grating thrust sensor as the calibration object, then the host computer can determine the thrust of the valve stem according to the following formula (5) based on the relationship between the offset of the first center wavelength, the offset of the second center wavelength and the thrust, and the acquired first center wavelength and second center wavelength:

[0081]

[0082] Where: Th is the central wavelength of the fiber Bragg grating thrust sensor when the valve is in motion; is the central wavelength of the fiber Bragg grating thrust sensor when the valve stem is not stressed and at temperature T0; is the temperature coefficient of the fiber Bragg grating thrust sensor; K F (T) is the force sensitivity of the fiber Bragg grating thrust sensor installed on the valve stem at the valve operating temperature T. Where T is obtained according to the above formula (4).

[0083] It is understandable that in order to ensure the accuracy of the strategy and eliminate the influence of temperature, e.g. Figure 3 As shown, two fiber Bragg grating thrust sensors may be fixed in the axial direction of the valve stem, and a fiber Bragg grating temperature sensor may also be fixed on the surface of the valve stem. In this way, the host computer may respectively obtain the first center wavelengths of the two fiber Bragg grating thrust sensors collected by the fiber Bragg grating demodulator; determine the thrust exerted on the valve stem based on the first center wavelength of each fiber Bragg grating thrust sensor obtained and the relationship between the offset of the first center wavelength and the thrust; and then determine the average of the two determined thrusts as the thrust exerted on the valve stem.

[0084] The method of determining the mean value based on the first central wavelength of each fiber Bragg grating thrust sensor can be obtained by using the relevant part of the above formula (3) or formula (5), which is not limited in the present application.

[0085] In one embodiment, the valve stem surface includes at least one uniformly stressed section, and a fiber grating thrust sensor is fixed to any uniformly stressed section, that is, the fiber grating thrust sensor is fixed to the uniformly stressed section on the valve stem surface. On the one hand, the overall occupied area of ​​the valve stem with the grating fiber sensor installed is reduced, and the valve stem is prevented from being unable to be used in the valve due to the sensor being directly installed on the valve stem surface. On the other hand, fixing the fiber grating thrust sensor to the uniformly stressed section on the valve stem surface can also facilitate the installation of the fiber grating thrust sensor.

[0086] like Figure 2 As shown, in a specific embodiment, the valve stem surface includes two evenly stressed sections, and the two evenly stressed sections are symmetrically located on the surfaces of both sides of the valve stem along the axial direction of the valve stem.

[0087] The fiber grating thrust sensor may be fixed on the surface of the valve stem by welding or gluing, which is not limited in the present application.

[0088] Considering that the fiber Bragg grating sensor is directly fixed on the surface of the valve stem, which makes the fiber Bragg grating sensor vulnerable, therefore, in one embodiment, the valve stem also includes at least one metal protective shell, wherein any metal protective shell is connected to the valve stem by welding and is covered in a uniformly stressed section to protect the fiber Bragg grating thrust sensor.

[0089] In another embodiment, in order to make the fiber Bragg grating sensor less prone to damage, the fiber Bragg grating thrust sensor and the temperature sensor may also be a fiber Bragg grating thrust sensor using metal packaging.

[0090] Corresponding to the above-mentioned valve stem thrust detection system, the present application also proposes an intelligent valve stem, which includes the valve stem in any of the above-mentioned embodiments.

[0091] like Figure 4 As shown, corresponding to the above-mentioned valve stem thrust detection system, the present application also proposes a valve stem thrust detection method, wherein at least one fiber Bragg grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem, the central wavelength of the at least one fiber Bragg grating thrust sensor changes based on the axial strain of the valve stem, the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect the first central wavelength of the at least one fiber Bragg grating thrust sensor; the method comprises:

[0092] S401, outputting thrust to the valve stem through an actuator to drive the valve stem to move;

[0093] S402, when the valve stem moves, acquiring a first central wavelength of the at least one fiber Bragg grating thrust sensor collected by a fiber Bragg grating demodulator;

[0094] S403, determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength.

[0095] In one embodiment, a fiber Bragg grating temperature sensor is also fixed on the valve stem surface, and the fiber Bragg grating temperature sensor and the at least one fiber Bragg grating thrust sensor are in the same temperature field; the central wavelength of the fiber Bragg grating temperature sensor changes based on the temperature of the valve stem, and the pigtail of the fiber Bragg grating temperature sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect the second central wavelength of the fiber Bragg grating temperature sensor; the method further comprises: when the valve stem moves, obtaining the second central wavelength of the fiber Bragg grating temperature sensor collected by the fiber Bragg grating demodulator;

[0096] The step S403 specifically includes: determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength.

[0097] In one embodiment, two fiber grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber grating thrust sensors are symmetrically fixed on the surfaces on both sides of the valve stem; S402 specifically comprises: respectively obtaining the first center wavelengths of the two fiber grating thrust sensors acquired by the fiber grating demodulator; S403 specifically comprises: respectively determining the thrust exerted on the valve stem based on the first center wavelength of each fiber grating thrust sensor obtained and the relationship between the offset of the first center wavelength and the thrust; and determining the average of the two determined thrusts as the thrust exerted on the valve stem.

[0098] In one embodiment, two fiber Bragg grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber Bragg grating thrust sensors are symmetrically fixed on the surfaces on both sides of the valve stem; S402 specifically comprises: respectively obtaining the first central wavelengths of the two fiber Bragg grating thrust sensors acquired by the fiber Bragg grating demodulator; S403 specifically comprises: determining the thrust exerted on the valve stem based on the first central wavelength and the second central wavelength of each fiber Bragg grating thrust sensor obtained, and the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust; and determining the average of the two determined thrusts as the thrust exerted on the valve stem.

[0099] like Figure 5 and Figure 6 As shown in the figure, the valve stem thrust measured by the fiber Bragg grating thrust sensor during the opening and closing process of the electric gate valve under different medium pressures varies with the stroke: (a) opening stroke; (b) closing stroke.

[0100] (a) and (b) show the change of valve stem thrust along with stroke measured by the fiber grating sensor installed on the valve stem surface during the opening and closing process of an electric gate valve under different pressure conditions. The measurement results of the valve stem thrust are completely consistent with the change law of the valve stem thrust when the electric gate valve is fully opened and closed.

[0101] like Figure 7 and Figure 8 As shown, the change of valve stem thrust with stroke measured by the fiber grating thrust sensor during the opening and closing process of the no-load electric gate valve: (a) opening stroke; (b) closing stroke.

[0102] (a) and (b) are respectively the opening and closing process of an electric gate valve under no-load, and the changes of the valve stem thrust with stroke measured by the fiber Bragg grating thrust sensor installed on the valve stem surface. The results show that the two fiber Bragg grating thrust sensors that are 180° symmetrical along the circumference of the valve stem have a certain bending deformation of the valve stem, resulting in uneven force on both sides. The average of the valve stem thrust measured by the two fiber Bragg grating thrust sensors can obtain the valve stem thrust more accurately.

[0103] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.

[0104] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these modifications and variations.

Claims

1. A valve stem thrust detection method, characterized in that: At least one fiber Bragg grating thrust sensor is fixed on the valve stem surface along the axial direction of the valve stem, the central wavelength of the at least one fiber Bragg grating thrust sensor changes based on the axial strain of the valve stem, and the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect a first central wavelength of the at least one fiber Bragg grating thrust sensor; the method comprises: Outputting thrust to the valve stem through an actuator to drive the valve stem to move; When the valve stem moves, obtaining a first central wavelength of the at least one fiber Bragg grating thrust sensor collected by a fiber Bragg grating demodulator; The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength.

2. The method according to claim 1, characterized in that A fiber Bragg grating temperature sensor is also fixed on the valve stem surface, and the fiber Bragg grating temperature sensor and the at least one fiber Bragg grating thrust sensor are in the same temperature field; the central wavelength of the fiber Bragg grating temperature sensor changes based on the temperature of the valve stem, and the pigtail of the fiber Bragg grating temperature sensor is connected to a fiber Bragg grating demodulator, and the fiber Bragg grating demodulator is used to collect the second central wavelength of the fiber Bragg grating temperature sensor; the method further comprises: when the valve stem moves, obtaining the second central wavelength of the fiber Bragg grating temperature sensor collected by the fiber Bragg grating demodulator; The determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength includes: The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength.

3. The method according to claim 1, characterized in that Two fiber Bragg grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber Bragg grating thrust sensors are symmetrically fixed on the surfaces of both sides of the valve stem; The step of acquiring the first central wavelength of the at least one fiber Bragg grating thrust sensor acquired by the fiber Bragg grating demodulator comprises: Respectively acquiring the first central wavelengths of the two fiber Bragg grating thrust sensors collected by the fiber Bragg grating demodulator; Determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength includes: Determine the thrust exerted on the valve stem based on the acquired first central wavelength of each fiber Bragg grating thrust sensor and the relationship between the offset of the first central wavelength and the thrust; The average of the two determined thrusts is determined as the thrust exerted on the valve stem.

4. The method according to claim 2, characterized in that: Two fiber Bragg grating thrust sensors are fixed on the surface of the valve stem along the axial direction of the valve stem, wherein the two fiber Bragg grating thrust sensors are symmetrically fixed on the surfaces of both sides of the valve stem; The step of acquiring the first central wavelength of the at least one fiber Bragg grating thrust sensor acquired by the fiber Bragg grating demodulator comprises: Respectively acquiring the first central wavelengths of the two fiber Bragg grating thrust sensors collected by the fiber Bragg grating demodulator; The method of determining the thrust exerted on the valve stem based on the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust, and the acquired first central wavelength and second central wavelength, comprises: Determine the thrust exerted on the valve stem based on the first central wavelength and the second central wavelength of each fiber Bragg grating thrust sensor, and the relationship between the offset of the first central wavelength, the offset of the second central wavelength and the thrust; The average of the two determined thrusts is determined as the thrust exerted on the valve stem.

5. A valve stem thrust detection system, characterized in that: Including valves, fiber grating demodulator and host computer; At least one fiber Bragg grating thrust sensor is fixed on the valve stem surface of the valve along the axial direction of the valve stem, the central wavelength of the at least one fiber Bragg grating thrust sensor changes based on the axial strain of the valve stem, and the pigtail of the at least one fiber Bragg grating thrust sensor is connected to a fiber Bragg grating demodulator; The valve stem is used to act according to the output thrust of the actuator; The fiber Bragg grating demodulator is used to collect the first central wavelength of the at least one fiber Bragg grating thrust sensor; The host computer is used to obtain the first central wavelength of the at least one fiber Bragg grating thrust sensor collected by the fiber Bragg grating demodulator when the valve stem moves; The thrust exerted on the valve stem is determined based on the relationship between the offset of the first central wavelength and the thrust and the acquired first central wavelength.

6. The system according to claim 5, characterized in that The valve stem surface includes at least one uniformly stressed section, and a fiber grating thrust sensor is fixed to any uniformly stressed section.

7. The system according to claim 6, characterized in that The valve stem surface comprises two evenly stressed sections, and the two evenly stressed sections are symmetrically arranged on the surfaces of both sides of the valve stem along the axial direction of the valve stem.

8. The system according to claim 5, characterized in that The at least one fiber grating thrust sensor is fixed on the surface of the valve stem by welding or gluing.

9. The system according to claim 6, characterized in that The valve stem further comprises at least one metal protective shell, wherein any metal protective shell is connected to the valve stem by welding and covers a uniformly stressed section to protect the fiber grating thrust sensor.

10. The system according to claim 5, characterized in that The fiber grating thrust sensor is a fiber grating thrust sensor using metal packaging.

11. The system according to claim 5, characterized in that A fiber grating temperature sensor is also fixed on the valve stem surface. The fiber grating temperature sensor and the at least one fiber grating thrust sensor are in the same temperature field. The tail fiber of the fiber grating temperature sensor is connected to a fiber grating demodulator.

12. An intelligent valve stem, characterized in that: The smart valve stem is the valve stem described in any one of claims 5-11.

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