A wire mesh sensor suitable for high temperature and high pressure environment

Abstract

The application discloses a wire screen sensor suitable for high-temperature and high-pressure environment, wherein an emitter and a receiver arranged in vertical staggered mode are installed perpendicularly to the flowing direction in a high-temperature and high-pressure geometric flow channel. The emitter and the receiver are made of enameled wire to ensure insulation between the emitter and the receiver. Meanwhile, one end of the emitter and the receiver is connected with a rigid wiring terminal, and the other end is connected with a rigid signal connecting wire. The rigid wiring terminal is embedded in the inner side insulation ceramic of the flow channel. After penetrating the inner side insulation ceramic layer of the flow channel, the rigid signal connecting wire is connected with an excitation source or a signal collector and is sealed with the outer wall surface of the flow channel. Thus, the phase state distribution imaging measurement of gas-liquid two-phase flow under high-temperature and high-pressure environment is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of two-phase flow measurement, and particularly relates to a wire mesh sensor suitable for high temperature and high pressure environments. Background Technology

[0002] Two-phase flow is widely present in various industrial equipment such as nuclear reactors, bubblers, and heat exchangers, and it causes intense mass, momentum, and energy exchange between the two phases. Due to the extremely high requirements for the performance and reliability of measuring instruments in high-temperature and high-pressure environments, measuring the phase distribution of two-phase flow under these conditions is very difficult.

[0003] Two-phase flow measurements in high-temperature and high-pressure environments typically employ radiation measurement techniques. These techniques utilize the varying attenuation of radiation as it penetrates different materials. Based on the intensity of the radiation after penetrating the two-phase flow, the phase distribution and interface structure within the flow channel can be reconstructed. During operation, a high-energy electron beam generated by an electric gun strikes a metal target, producing high-energy radiation. By rapidly moving the electron beam along a ring target, the phase distribution and interface structure at the flow channel cross-section can be measured.

[0004] Irradiation measurement technology requires large, complex, and expensive equipment, making it difficult to adapt to complex and ever-changing industrial environments. Furthermore, due to the involvement of radiation, obtaining the necessary certifications is extremely cumbersome. Therefore, its application scope is severely limited. Summary of the Invention

[0005] The purpose of this invention is to provide a wire mesh sensor suitable for high temperature and high pressure environments, which can realize phase distribution imaging measurement of two-phase flow under high temperature and high pressure environments without the need for irradiation measurement technology.

[0006] To solve the above problems, the technical solution of the present invention is as follows:

[0007] A wire mesh sensor suitable for high temperature and high pressure environments includes: an outer flow channel, an insulated inner flow channel, several emitters and receivers, an excitation source, and a signal acquisition unit;

[0008] The emitter and receiver are arranged perpendicularly and alternately to form a wire mesh, which is installed in the insulating inner flow channel; the wire mesh is perpendicular to the flow direction of the gas-liquid two-phase flow;

[0009] The insulating inner flow channel is located inside the outer flow channel. Several through holes are opened at the relative positions of the insulating inner flow channel and the outer flow channel for the electrical signal connection between the emitter and the excitation source, and the electrical signal connection between the receiver and the signal acquisition device.

[0010] A sealing element is installed at the through hole on the outer flow channel to seal the signal line passing through the through hole and the outer flow channel;

[0011] The sealing element includes a sealing ring and a sealing flange. The sealing ring is placed inside the through hole and sleeved on the signal line. The sealing flange is set on the outer surface of the outer flow channel and is parallel to the flow direction of the gas-liquid two-phase flow to seal the signal line and the outer flow channel. The sealing flange realizes the installation and sealing of the signal line on one side wall of the outer flow channel in one step.

[0012] During measurement, the excitation source sequentially excites each emitter individually, while the signal acquisition unit records the electrical signal of the receiver. For all emitters and receivers, a measurement frame is completed after each sequential excitation and signal reception.

[0013] According to one embodiment of the present invention, the insulating inner flow channel includes a ceramic wall, in which a rigid terminal is embedded, the rigid terminal being used to connect an electrode wire of an emitter or a receiver; the other end of the electrode wire is rigidly connected to a rigid signal connection line, the rigid signal connection line passing through the ceramic wall and through a through hole in the outer flow channel.

[0014] According to one embodiment of the present invention, the ceramic wall includes a first wall segment and a second wall segment, wherein the first wall segment and the second wall segment are spliced ​​together in a sawtooth structure to form the ceramic wall.

[0015] According to one embodiment of the present invention, the diameter of the electrode wire does not exceed 0.5 mm.

[0016] According to one embodiment of the present invention, the surfaces of the emitter, receiver, and rigid signal connection line are insulated.

[0017] According to one embodiment of the present invention, the outer flow channel is connected to an electric heating device, and a high-temperature and high-pressure gas-liquid two-phase flow is obtained by electric heating, wherein the pressure of the high-temperature and high-pressure gas-liquid two-phase flow does not exceed 22 MPa.

[0018] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0019] In one embodiment of the present invention, a wire mesh sensor suitable for high-temperature and high-pressure environments comprises emitters and receivers arranged perpendicularly and alternately within a high-temperature and high-pressure geometric flow channel. The emitters and receivers are made of enameled wire to ensure insulation between them. Simultaneously, one end of each emitter and receiver is connected to a rigid terminal, and the other end is connected to a rigid signal connection line. The rigid terminal is embedded in the insulating ceramic layer inside the flow channel. The rigid signal connection line penetrates the insulating ceramic layer inside the flow channel and emerges from the outer wall of the flow channel to connect to an excitation source or signal acquisition device; the rigid signal connection line is sealed to the outer wall of the flow channel. This enables imaging measurement of the phase distribution of a gas-liquid two-phase flow under high-temperature and high-pressure conditions. Attached Figure Description

[0020] Figure 1This is a top cross-sectional view of a wire mesh sensor suitable for high temperature and high pressure environments according to an embodiment of the present invention;

[0021] Figure 2 This is a side cross-sectional view of the wire mesh installation in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a sealing flange in one embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1: Outer flow channel; 2: Insulated inner flow channel; 3: Emitter; 4: Receiver; 5: Rigid terminal; 6: Rigid signal connection line; 7: Excitation source; 8: Signal acquisition device; 9: Sealing ring; 10: Sealing flange; 101: Through hole; 102: Bolt fixing hole; 11: Ceramic wall; 12: High temperature insulating varnish. Detailed Implementation

[0025] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a more detailed explanation of a wire mesh sensor suitable for high-temperature and high-pressure environments proposed in this invention. The advantages and features of this invention will become clearer from the following description and claims.

[0026] This embodiment provides a wire mesh sensor suitable for high-temperature and high-pressure environments. The wire mesh sensor measures the instantaneous cavitation fraction across the cross-section of a gas-liquid two-phase flow, thereby enabling phase distribution imaging of the gas-liquid two-phase flow under high-temperature and high-pressure conditions. The wire mesh sensor comprises two layers of perpendicularly intersecting and insulated metal wires: one layer is the transmitting electrode, and the other is the receiving electrode. An excitation voltage is sequentially applied to the transmitting electrode, while the receiving electrode maintains a zero potential. Because the receiving electrode, maintaining a zero potential, shields the electric field within a certain area, the wire mesh sensor achieves the measurement of local capacitance.

[0027] For details, please refer to Figure 1 This wire mesh sensor, suitable for high-temperature and high-pressure environments, includes: an outer flow channel 1, an insulating inner flow channel 2, several emitters 3 and receivers 4, an excitation source 7, and a signal acquisition unit 8. The emitters 3 and receivers 4 are arranged perpendicularly and alternately to form a wire mesh, which is installed within the insulating inner flow channel 2, perpendicular to the flow direction of the gas-liquid two-phase flow. The insulating inner flow channel 2 is installed inside the outer flow channel 1, which is rectangular. Several through holes are formed at the relative positions of the insulating inner flow channel 2 and the outer flow channel 1 for electrical signal connection between the emitters 3 and the excitation source 7, and between the receivers 4 and the signal acquisition unit 8. Sealing elements are installed at the through holes in the outer flow channel 1 to seal the signal lines passing through the through holes from the outer flow channel.

[0028] Please refer to Figure 1 and Figure 2This embodiment employs a 6×6 wire mesh sensor, comprising six emitters 3 and six receivers 4. Both emitters 3 and receivers 4 are made of enameled wire and arranged in a vertically staggered pattern, maintaining contact while being mutually insulated. One end of each emitter 3 and receiver 4 is rigidly connected to a rigid terminal 5, and the other end is rigidly connected to a rigid signal connection line 6. The rigid terminal 5 is embedded in the insulated inner flow channel 2, and the rigid signal connection line 6 passes through the insulated inner flow channel 2 and the outer flow channel 1, electrically connecting to the excitation source 7 or the signal acquisition device 8. The rigid signal connection line 6 is sealed to the outer flow channel 1 by a sealing element.

[0029] The sealing element includes a sealing ring 9 and a sealing flange 10. The sealing ring 9 is placed inside the through hole and sleeved on the rigid signal connection line 6 to achieve an internal seal between the rigid signal connection line 6 and the external flow channel 1. The sealing ring 9 can be a metal O-ring or a silicone sealing ring.

[0030] A sealing flange 10 is disposed on the outer surface of the outer flow channel 1 and, parallel to the flow direction of the gas-liquid two-phase flow, provides an external seal between the rigid signal connection line 6 and the outer flow channel 1. Please refer to [link / reference]. Figure 3 The sealing flange 10 is elongated and has multiple rigid signal connection wire through holes 101. The number of through holes 101 is the same as the number of through holes on a certain wall surface of the current external flow channel 1, and the spacing between the through holes is also consistent. This ensures that after the sealing flange 10 is fixed to the surface of the external flow channel 1, the through holes of the external flow channel are aligned with the through holes on the sealing flange. The sealing flange 10 also has multiple bolt fixing holes 102, which are used to fix the sealing flange to the external flow channel by passing bolts through them.

[0031] This embodiment achieves easy sealing of the wire mesh installation location using the aforementioned sealing element. Traditional methods, which only use flanges and gaskets for sealing the end face of the flow channel cross-section, are not suitable for sealing the wire mesh installation location in this embodiment. The sealing element in this embodiment achieves a superior sealing effect while saving space and facilitating installation.

[0032] To prevent environmental influences on the acquired signals, the surface of the rigid signal connection line 6 is coated with high-temperature insulating varnish 12.

[0033] In this embodiment, the insulated inner flow channel 2 includes a ceramic wall 11, within which a rigid terminal 5 is embedded. This rigid terminal 5 is used to connect the electrode wires of the emitter 2 or receiver 3. The other end of the electrode wire is rigidly connected to a rigid signal connection line 6, which passes through the ceramic wall 11 and through a through-hole in the outer flow channel 1. The diameter of the electrode wire does not exceed 0.5 mm. The lateral spacing between the emitters and receivers of the mesh is not less than 1 mm.

[0034] To improve the fitting accuracy of the insulated inner flow channel and ensure the measurement accuracy of the wire mesh sensor, the insulated inner flow channel 2 is constructed using a sawtooth structure. Specifically, the ceramic wall 11 is divided into a first wall segment and a second wall segment, which are joined together using a sawtooth structure to form the ceramic wall 11. Since the rigid signal connection lines of the wire mesh pass through the insulated inner flow channel, the fitting accuracy of the two ceramic wall segments is more critical; the sawtooth structure improves this accuracy. Otherwise, poor fitting will alter the distance between the emitter and receiver of the wire mesh, affecting the final measurement results.

[0035] During measurement, an electric heating device is connected to the outer flow channel to pressurize and heat the gas-liquid two-phase flow, resulting in a high-temperature, high-pressure gas-liquid two-phase flow. The pressure of this high-temperature, high-pressure gas-liquid two-phase flow does not exceed 22 MPa, and the corresponding temperature does not exceed 373.71℃. The excitation source outputs a high-frequency AC voltage to sequentially and individually excite each emitter, while the signal acquisition device records the current signal of the receiver at a frequency not lower than 1000 Hz. For all emitters and receivers, one frame of measurement is completed after each sequential excitation and signal reception. The magnitude of the current received by the receiver characterizes the instantaneous cavitation fraction at the junction of the emitter and receiver. The local cavitation fraction at each junction of the emitter and receiver is measured, and the average cross-sectional cavitation fraction is calculated from this, thus obtaining the cavitation fraction distribution of the gas-liquid two-phase flow within the flow channel.

[0036] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A wire mesh sensor suitable for high temperature and high pressure environments, characterized in that, include: External flow channel, insulated internal flow channel, several emitters and receivers, excitation source and signal acquisition device; The emitter and receiver are arranged perpendicularly and alternately to form a wire mesh, which is installed in the insulating inner flow channel. The wire mesh is perpendicular to the flow direction of the gas-liquid two-phase flow. The insulating inner flow channel includes a ceramic wall with a rigid terminal embedded in it. The rigid terminal is used to connect the electrode wires of the emitter or receiver. The other end of the electrode wire is connected to a rigid signal connection line, which passes through the ceramic wall and through the through hole of the outer flow channel. The surfaces of the emitter, receiver, and rigid signal connection line are insulated. The emitter and receiver are made of enameled wire. The ceramic wall includes a first wall segment and a second wall segment, which are spliced ​​together in a sawtooth structure to form the ceramic wall. The insulating inner flow channel is located inside the outer flow channel. Several through holes are opened at the relative positions of the insulating inner flow channel and the outer flow channel for the electrical signal connection between the emitter and the excitation source, and the electrical signal connection between the receiver and the signal acquisition device. A sealing element is installed at the through hole on the outer flow channel to seal the rigid signal connection line passing through the through hole and the outer flow channel; The sealing element includes a sealing ring and a sealing flange. The sealing ring is placed inside the through hole and sleeved on the rigid signal connection line. The sealing flange is set on the outer surface of the outer channel to seal the rigid signal connection line and the outer channel. The sealing flange realizes the installation and sealing of the rigid signal connection line on one side wall of the outer channel. During measurement, the excitation source sequentially excites each emitter individually, while the signal acquisition unit records the electrical signal of the receiver. For all emitters and receivers, a measurement frame is completed after each sequential excitation and signal reception.

2. The wire mesh sensor suitable for high temperature and high pressure environments as described in claim 1, characterized in that, The diameter of the electrode wire does not exceed 0.5 mm.

3. The wire mesh sensor suitable for high temperature and high pressure environments as described in claim 1, characterized in that, The outer flow channel is connected to an electric heating device, and a high-temperature and high-pressure gas-liquid two-phase flow is obtained through electric heating. The pressure of the high-temperature and high-pressure gas-liquid two-phase flow does not exceed 22 MPa.

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