A method and system for synchronous measurement of phase field temperature field in a hot-rod bundle channel

Abstract

This invention relates to the field of two-phase fluid measurement technology, and particularly discloses a method and system for synchronously measuring the phase and temperature fields within a hot rod bundle channel. The method includes: constructing a rod bundle channel using a fuel rod simulator within the flow channel; directly heating the fluid; and simultaneously measuring the phase and temperature fields of the rod bundle channel using a wire mesh sensor. Specifically, an AC signal excites the fiber optic cladding on the wire mesh sensor, which transmits and receives the signal. After analyzing and processing the signal, the fluid cavitation distribution is measured. An AC signal also excites the fiber optic cable of the wire mesh sensor, transmitting and converting an optical signal to measure the fluid temperature distribution. This method, implemented through a synchronous phase and temperature field measurement system within a hot rod bundle channel, provides a measurement method and system for synchronously measuring phase and temperature distributions in two-phase flows under high-temperature and high-pressure environments, specifically for complex rod bundle channels.

Description

Technical Field

[0001] This invention relates to the field of two-phase fluid measurement technology, and in particular to a method and system for synchronous measurement of phase field temperature field in a hot rod bundle channel. Background Technology

[0002] Two-phase boiling is a widespread phenomenon in industrial systems such as bubblers, steam generators, and nuclear reactors. When boiling occurs, the complex gas-liquid coupling caused by the two-phase flow affects the system's pressure drop, heat transfer, and energy and mass transfer properties. In particular, for common pressurized water reactors, boiling can lead to fuel element damage and safety accidents. Therefore, clarifying the phase state and temperature distribution characteristics within the rod bundle channel under high-temperature and high-pressure two-phase flow conditions is crucial. However, the complex structure of the rod bundle channel and the stringent requirements placed on the performance of measuring instruments under high-temperature and high-pressure reactor conditions make it difficult to accurately measure the phase field and temperature field distribution within the rod bundle channel under full-temperature and full-pressure conditions.

[0003] Currently, irradiation techniques are typically used to measure the cavitation fraction distribution under high temperature and high pressure conditions, based on the varying attenuation of rays as they penetrate different materials. The temperature distribution of two-phase fluids is usually measured using thermocouples. However, irradiation equipment is complex, has low resolution, and the rays attenuate multiple times as they pass through the rod bundle, making signal capture difficult and resulting in poor measurement accuracy, thus limiting its application to complex rod bundle channel structures. Furthermore, the volume of the thermocouple itself can cause significant intrusion into the flow field, hindering the measurement of high-resolution temperature fields.

[0004] Therefore, there is an urgent need to design a system and method for synchronous measurement of phase field and temperature field in complex rod bundle channels under high temperature and high pressure conditions. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a method and system for synchronous measurement of phase field temperature field in a hot rod bundle channel, which is designed for the synchronous measurement of phase distribution and temperature distribution in two-phase flow in complex rod bundle channels.

[0006] One method for synchronously measuring the phase field temperature field within a hot rod bundle channel is provided, including:

[0007] Within the flow channel, a rod bundle channel is constructed using a fuel rod simulator to directly heat the fluid. A wire mesh sensor is used to simultaneously measure the phase field and temperature field of the rod bundle channel.

[0008] The optical fiber cladding on the wire mesh sensor is excited by an alternating current signal. The optical fiber cladding transmits and receives the electrical signal. After analyzing and processing the electrical signal, the fluid cavitation distribution is measured.

[0009] The optical fiber of the wire mesh sensor is excited by an alternating current signal to transmit and convert the optical signal, thereby measuring the temperature distribution of the fluid.

[0010] Furthermore, direct heating of the fluid further includes:

[0011] The effective heating section of the simulator is isolated from its copper electrodes by an insulating ring. The copper electrodes are connected to a DC power supply, and the heating power of the simulator is controlled by adjusting the current.

[0012] Furthermore, the optical fiber cladding on the wire mesh sensor is excited by an alternating current signal, and the optical fiber cladding transmits and receives the electrical signal, which further includes:

[0013] An alternating current is input to the emitter of the wire mesh sensor, and the optical fiber cladding of the emitter is excited by the alternating current signal. The receiver receives the electrical signal and transmits it to the electrical signal acquisition card to measure the fluid phase field.

[0014] Preferably, measuring the fluid cavitation fraction distribution further includes:

[0015] S11: The electrical signal acquisition card accurately receives electrical signals and conditions and converts the received electrical signals, including amplifying weak electrical signals and removing noise and interference from the electrical signals;

[0016] S12: Perform spectrum analysis on the AC signal to determine its frequency components and amplitude distribution, detect the phase difference between the received signal and the excitation signal using a phase detection algorithm, and extract the characteristic parameters of the signal.

[0017] S13: Considering the material properties of the fiber cladding, the frequency and amplitude of the excitation signal, establish a phase field model, continuously acquire electrical signals, and calculate the phase field value in real time based on the established phase field model and the extracted electrical signal characteristic parameters.

[0018] S14: Consider possible sources of error, perform error analysis on the measurement results, assess the accuracy of the measurement, take appropriate measures to correct it, and output the measurement results in the form of a data file.

[0019] Furthermore, the process of exciting the optical fiber of the wire mesh sensor with an alternating current signal to transmit and convert the optical signal further includes:

[0020] The optical signal emission model emits an optical signal to the wire mesh sensor, which excites the optical fibers in the emitter and receiver of the wire mesh sensor. The optical signal is received and read by the optical fiber tuner, and the optical signals of different wavelengths are converted into temperature values ​​to realize the measurement of the fluid temperature field.

[0021] Preferably, measuring the fluid temperature distribution further includes:

[0022] S21: Temperature measurement at different locations in a fluid is achieved by arranging several emitters and receivers in the fluid. The optical fiber path between each emitter and receiver covers a certain area. A grating for measurement is etched on the optical fiber to form a temperature measurement network.

[0023] S22: Construct the temperature field of the fluid based on the temperature measurements at various locations, and generate a three-dimensional spatial function describing the temperature distribution in the fluid.

[0024] On the other hand, the present invention provides a synchronous measurement system for the phase field temperature field within a hot rod bundle channel, comprising a flow channel, a simulation body, and a wire mesh sensor:

[0025] The simulation body and the wire mesh sensor are disposed within the flow channel. The flow channel wall is isolated from the simulation body by an insulating material. The wire mesh sensor is perpendicular to the simulation body, and the wire mesh sensor and the simulation body are isolated by an isolation ring.

[0026] Furthermore, the simulation body includes an effective heating section and a copper electrode section, both of which are internally encased in heating tubes. The effective heating section and the copper electrode section are isolated by an insulating ring.

[0027] In the effective heating section, the heating tube is sequentially covered with an insulating layer and a heating shell.

[0028] In the copper electrode section, the heating element is wrapped with a copper tube;

[0029] The wire mesh sensor includes several emitters and receivers, which are perpendicular to each other but do not intersect.

[0030] Furthermore, the emitter and receiver of the wire mesh sensor are rigidly connected to a fixed end, the fixed end including an optical fiber and an optical fiber cladding, the optical fiber cladding covering the optical fiber, and the outer coating of the optical fiber cladding having an extremely thin insulating layer.

[0031] The optical fiber needs to be etched with a grating according to the measurement resolution;

[0032] The optical fiber cladding is connected to the electrical signal acquisition card, one end of the optical fiber is connected to the optical signal transmitting module, and the other end is connected to the optical fiber tuner.

[0033] Furthermore, the fixed end of the optical fiber extends from both sides of the flow channel, and the simulation body extends from the upper and lower ends of the flow channel, and is sealed with O-rings. The various parts inside the flow channel are connected to the flow channel through flanges.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] This invention constructs a rod bundle channel using a fuel rod simulator and sets up a wire mesh sensor to simultaneously measure the cavitation fraction distribution and temperature distribution of the fluid within the rod bundle channel. In a complex rod bundle channel structure, it achieves simultaneous measurement of the phase field and temperature field of the rod bundle channel under high temperature and high pressure conditions.

[0036] This invention avoids interference from the two-phase measurement error of the rod bundle channel by setting a high-temperature insulation layer between the heating tube and other components. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a flowchart of a method for synchronously measuring the phase field temperature field within a hot rod bundle channel according to the present invention.

[0039] Figure 2 This is a schematic diagram of the overall structure of a rod bundle channel according to the present invention;

[0040] Figure 3 This is a schematic diagram of the front structure of a fuel rod simulator according to the present invention;

[0041] Figure 4 This is a top view cross-sectional structural diagram of the effective heating section of a fuel rod simulator according to the present invention;

[0042] Figure 5 This is a schematic diagram of a wire mesh sensor arrangement according to the present invention.

[0043] Figure Labels

[0044] 1: Flow channel; 2: Simulation body; 3: Screen sensor;

[0045] 11: Insulating material; 12: Insulating ring-1; 13: O-ring seal; 14: Flange;

[0046] 21: Effective heating section; 22: Copper electrode section; 23: Heating element; 24: Insulating ring-2;

[0047] 211: Insulation layer-1; 212: Heating casing;

[0048] 221: Copper pipe;

[0049] 31: Emitter; 32: Receiver; 33: Optical fiber; 34: Optical fiber cladding; 35: Fixed end; 36: Electrical signal acquisition card; 37: Optical signal transmission module; 38: Insulation layer-2. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0052] like Figure 1 As shown, this embodiment provides a method for synchronously measuring the phase field temperature field within a hot rod bundle channel. The technical solution includes:

[0053] Within the flow channel, a rod bundle channel is constructed using a fuel rod simulator to directly heat the fluid. A wire mesh sensor is used to simultaneously measure the phase field and temperature field of the rod bundle channel.

[0054] The optical fiber cladding on the wire mesh sensor is excited by an alternating current signal. The optical fiber cladding transmits and receives the electrical signal. After analyzing and processing the electrical signal, the fluid cavitation distribution is measured.

[0055] The optical fiber of the wire mesh sensor is excited by an alternating current signal to transmit and convert the optical signal, thereby measuring the temperature distribution of the fluid.

[0056] Direct heating of the fluid further includes:

[0057] The effective heating section of the simulator is isolated from its copper electrodes by an insulating ring. The copper electrodes are connected to a DC power supply, and the heating power of the simulator is controlled by adjusting the current.

[0058] In this embodiment, the optical fiber cladding on the wire mesh sensor is excited by an alternating current signal, and the optical fiber cladding transmits and receives electrical signals, further comprising:

[0059] An alternating current is input to the emitter of the wire mesh sensor, and a high-frequency alternating current signal is used to excite the fiber optic cladding of the emitter. The receiver receives the electrical signal and transmits it to the electrical signal acquisition card for measuring the fluid phase field.

[0060] Specifically, the measurement of fluid cavitation distribution after electrical signal analysis and processing further includes:

[0061] S11: The electrical signal acquisition card accurately receives electrical signals and conditions and converts the received electrical signals, including amplifying weak electrical signals and removing noise and interference from the electrical signals;

[0062] S12: Perform spectrum analysis on the AC signal to determine its frequency components and amplitude distribution, detect the phase difference between the received signal and the excitation signal using a phase detection algorithm, and extract the characteristic parameters of the signal.

[0063] S13: Considering the material properties of the fiber cladding, the frequency and amplitude of the excitation signal, establish a phase field model, continuously acquire electrical signals, and calculate the phase field value in real time based on the established phase field model and the extracted electrical signal characteristic parameters.

[0064] S14: Consider possible sources of error, perform error analysis on the measurement results, assess the accuracy of the measurement, take appropriate measures to correct it, and output the measurement results in the form of a data file.

[0065] Furthermore, the optical fiber of the wire mesh sensor is excited by an alternating current signal to transmit and convert the optical signal, including:

[0066] The optical signal emission model emits an optical signal to the wire mesh sensor, which excites the optical fibers in the emitter and receiver of the wire mesh sensor. The optical signal is received and read by the optical fiber tuner, and the optical signals of different wavelengths are converted into temperature values ​​to realize the measurement of the fluid temperature field.

[0067] Measuring the fluid temperature distribution further includes:

[0068] S21: Temperature measurement at different locations in a fluid is achieved by arranging several emitters and receivers in the fluid. The optical fiber path between each emitter and receiver covers a certain area. A grating for measurement is etched on the optical fiber to form a temperature measurement network.

[0069] S22: Construct the temperature field of the fluid based on the temperature measurements at various locations, and generate a three-dimensional spatial function describing the temperature distribution in the fluid.

[0070] This embodiment provides a synchronous measurement system for the phase field temperature field within a hot rod bundle channel, used to implement the method described in Embodiment 1, such as... Figure 2 As shown, it includes flow channel 1, simulation body 2, and wire mesh sensor 3:

[0071] The simulation body 2 and the wire mesh sensor 3 are disposed in the flow channel 1 and are used to generate heat to heat the fluid and measure fluid parameters, respectively. The wall of the flow channel 1 is isolated from the simulation body 2 by an insulating material. The wire mesh sensor 3 is perpendicular to the simulation body 2 and the wire mesh sensor 3 and the simulation body 2 are isolated by an isolation ring-112.

[0072] Specifically, such as Figure 2 and 3 As shown, the simulation body 2 includes an effective heating section 21 and a copper electrode section 22. Heating tubes 23 are encased inside both the effective heating section 21 and the copper electrode section 22. The effective heating section 21 and the copper electrode section 22 are isolated by an insulating ring-2 24.

[0073] In the effective heating section 21, the heating tube 23 is sequentially covered by an insulating layer -1 211 and a heating shell 212.

[0074] In the copper electrode section 22, the heating tube 23 is wrapped with a copper tube 221;

[0075] like Figure 4 As shown, the wire mesh sensor 3 includes several emitters 31 and receivers 32, which can be triggered by both electrical and optical signals. The diameter is no greater than 1 mm. The emitters 31 and receivers 32 are perpendicular to each other but do not intersect.

[0076] Specifically, the emitter 31 and receiver 32 of the wire mesh sensor 3 are rigidly connected to the fixed end 35. The fixed end 35 includes an optical fiber 33 and an optical fiber cladding 34. The optical fiber cladding 34 covers the optical fiber 33 and is coated with an extremely thin high-temperature resistant insulating layer -2 38.

[0077] The optical fiber 33 needs to be engraved with gratings according to the measurement resolution, and the grating spacing is not less than 5mm.

[0078] The optical fiber cladding 34 is connected to the electrical signal acquisition card 36, one end of the optical fiber 33 is connected to the optical signal transmission module 37, and the other end is connected to the optical fiber tuner.

[0079] In addition, the fixed end 35 of the optical fiber 33 extends out from both sides of the flow channel, and the simulation body 2 extends out from the upper and lower ends of the flow channel and is sealed with an O-ring 13. The various parts inside the flow channel are connected to the flow channel through a flange 14.

[0080] As can be seen from the above, in this embodiment, we use nickel-based alloy tubes as fuel rod simulators to form the rod bundle channel, and use DC power supply to directly heat the fluid to achieve the simulation of two-phase operation.

[0081] The fuel rod simulator consists of an effective heating section 21 and a copper electrode section 22, which are connected and insulated from each other by an insulating ring 24. The effective heating section is made of a combination of a heating tube 23, an insulating layer 211, and a heating shell 212, while the copper electrode section 22 is made of a combination of a heating tube 23 and a copper tube 221, which is connected to a DC power supply.

[0082] The emitter 31 and receiver 32 of the wire mesh sensor 3 are perpendicular to each other but do not intersect. From the inside out, they are an optical fiber 33, a stainless steel cladding 34, and an insulating coating 38, respectively, and both ends are rigidly connected to the fixed end 35. The emitter stainless steel cladding 34 is excited by an AC signal, and the receiver 32 receives the signal and transmits it to the data acquisition card 36.

[0083] The optical fiber 33 in the emitter 31 and receiver 32 is excited by an optical signal, and the optical signal is read in the modulator to convert the optical signal of different wavelengths into temperature values.

[0084] The fuel rod simulator 2 and the wire mesh sensor 3 are arranged inside the stainless steel flow channel 1 and isolated by ceramic (insulating material 11). The fixed end 35 and the fuel rod simulator 2 pass through the ceramic (insulating material 11) and the stainless steel flow channel 1 and are sealed by an O-ring 13.

[0085] During the experiment, the heating power of the heating rod was controlled by adjusting the current to achieve different two-phase parameter conditions. After maintaining the operating parameters stable for three minutes, the fluid temperature and cavitation distribution were simultaneously measured using a wire mesh sensor 3.

[0086] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

[0087] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synchronously measuring the phase field temperature field within a hot rod bundle channel, characterized in that, include: Within the flow channel, a rod bundle channel is constructed using a fuel rod simulator to directly heat the fluid. A wire mesh sensor is used to simultaneously measure the phase field and temperature field of the rod bundle channel. The optical fiber cladding on the wire mesh sensor is excited by an alternating current signal. The optical fiber cladding transmits and receives the electrical signal. After analyzing and processing the electrical signal, the fluid cavitation distribution is measured. The optical fiber of the wire mesh sensor is excited by an alternating current signal to transmit and convert the optical signal, thereby measuring the fluid temperature distribution. The wire mesh sensor includes several emitters and receivers, which are perpendicular to each other but do not intersect. The emitter and receiver of the wire mesh sensor are rigidly connected to a fixed end. The fixed end includes an optical fiber and an optical fiber cladding. The optical fiber cladding covers the optical fiber and is coated with an extremely thin insulating layer. The optical fiber needs to be etched with a grating according to the measurement resolution; The optical fiber cladding is connected to the electrical signal acquisition card, one end of the optical fiber is connected to the optical signal transmitting module, and the other end is connected to the optical fiber tuner.

2. The method for synchronous measurement of phase field temperature field within a hot rod bundle channel according to claim 1, characterized in that, Direct heating of fluids further includes: The effective heating section of the simulator is isolated from its copper electrodes by an insulating ring. The copper electrodes are connected to a DC power supply, and the heating power of the simulator is controlled by adjusting the current.

3. The method for synchronous measurement of phase field temperature field within a hot rod bundle channel according to claim 1, characterized in that, Exciting the optical fiber cladding on the wire mesh sensor with an alternating current signal, the optical fiber cladding transmitting and receiving the electrical signal further includes: An alternating current is input to the emitter of the wire mesh sensor, and the optical fiber cladding of the emitter is excited by the alternating current signal. The receiver receives the electrical signal and transmits it to the electrical signal acquisition card to measure the fluid phase field.

4. The method for synchronous measurement of phase field temperature field within a hot rod bundle channel according to claim 3, characterized in that, The measurement of fluid cavitation fraction distribution after electrical signal analysis and processing further includes: S11: The electrical signal acquisition card accurately receives electrical signals and conditions and converts the received electrical signals, including amplifying weak electrical signals and removing noise and interference from the electrical signals; S12: Perform spectrum analysis on the AC signal to determine its frequency components and amplitude distribution, detect the phase difference between the received signal and the excitation signal using a phase detection algorithm, and extract the characteristic parameters of the signal. S13: Considering the material properties of the fiber cladding, the frequency and amplitude of the excitation signal, establish a phase field model, continuously acquire electrical signals, and calculate the phase field value in real time based on the established phase field model and the extracted electrical signal characteristic parameters. S14: Consider possible sources of error, perform error analysis on the measurement results, assess the accuracy of the measurement, take appropriate measures to correct it, and output the measurement results in the form of a data file.

5. The method for synchronous measurement of phase field temperature field within a hot rod bundle channel according to claim 1, characterized in that, The transmission and conversion of optical signals by exciting the optical fiber of the wire mesh sensor with an alternating current signal further includes: The optical signal emission model emits an optical signal to the wire mesh sensor, which excites the optical fibers in the emitter and receiver of the wire mesh sensor. The optical signal is received and read by the optical fiber tuner, and the optical signals of different wavelengths are converted into temperature values ​​to realize the measurement of the fluid temperature field.

6. The method for synchronous measurement of phase field temperature field within a hot rod bundle channel according to claim 1, characterized in that, Measuring the fluid temperature distribution further includes: S21: Temperature measurement at different locations in a fluid is achieved by arranging several emitters and receivers in the fluid. The optical fiber path between each emitter and receiver covers a certain area. A grating for measurement is etched on the optical fiber to form a temperature measurement network. S22: Construct the temperature field of the fluid based on the temperature measurements at various locations, and generate a three-dimensional spatial function describing the temperature distribution in the fluid.

7. A synchronous measurement system for the phase field temperature field within a hot rod bundle channel, used to implement the method described in any one of claims 1 to 6, characterized in that, Includes flow channels, simulation bodies, and wire mesh sensors: The simulation body and the wire mesh sensor are disposed in the flow channel. The flow channel wall is isolated from the simulation body by an insulating material. The wire mesh sensor is perpendicular to the simulation body. The wire mesh sensor and the simulation body are isolated by an isolation ring. The fixed end of the wire mesh sensor includes an optical fiber and an optical fiber cladding.

8. The synchronous measurement system for phase field temperature field within the hot rod bundle channel according to claim 7, characterized in that, The simulation body includes an effective heating section and a copper electrode section. Heating tubes are encased inside both the effective heating section and the copper electrode section. The effective heating section and the copper electrode section are isolated by an insulating ring. In the effective heating section, the heating tube is sequentially covered with an insulating layer and a heating shell. In the copper electrode section, the heating element is wrapped with a copper tube.

9. The synchronous measurement system for phase field temperature field within the hot rod bundle channel according to claim 8, characterized in that, The fixed end of the optical fiber extends from both sides of the flow channel, and the simulation body extends from the upper and lower ends of the flow channel. It is sealed with an O-ring. The various parts inside the flow channel are connected to the flow channel through flanges.

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