Oxygen concentration sensor coupled with temperature detection

Abstract

The invention discloses an oxygen concentration sensor coupled with temperature detection, and belongs to the technical field of oxygen concentration sensing, a temperature sensing module and a first signal quick connector form a temperature measuring unit, and the temperature sensing module is used for sensing a temperature signal when the temperature sensing module is immersed in liquid lead bismuth alloy; and temperature data are transmitted through the first signal quick connector. A Pt electrode, a positive electrode lead, a negative electrode connecting wire and a second signal quick connector form an electromotive force measuring unit which is used for sensing oxygen partial pressure difference between the liquid lead-bismuth alloy and a reference electrode when the YSZ ceramic tube is immersed in the liquid lead-bismuth alloy and transmitting electromotive force data through the second signal quick connector; and the measured temperature data and electromotive force data are synchronized, and the oxygen concentration is obtained through a Nernst equation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oxygen concentration sensing, and particularly relates to an oxygen concentration sensor coupled with temperature detection. BACKGROUND

[0002] One of the fourth generation reactor types, lead-based fast reactors, uses liquid lead or lead-bismuth eutectic alloy as the main coolant, which has several significant advantages, including high boiling point, low neutron absorption cross section, excellent high-temperature stability, and good thermal conductivity. These characteristics make it have great potential in improving reactor thermal efficiency, enhancing safety, and achieving longer operating cycles. However, the corrosion of liquid lead-bismuth alloy to structural materials at high temperatures limits the development of lead-based fast reactors. Studies have shown that by reasonably controlling the oxygen concentration in the liquid lead-bismuth system, a dense and stable oxidation protective film can be induced on the surface of the structural material, thereby significantly reducing the corrosion rate of the alloy to the material. Therefore, accurate detection and control of the dissolved oxygen concentration in the system has become a key technical link to ensure the long-term stable operation of the reactor.

[0003] In actual operation, the temperature fluctuation of liquid lead-bismuth will affect the solubility of oxygen, causing changes in the dissolved oxygen concentration. Currently, the oxygen control system generally uses oxygen sensors and thermocouples in combination to monitor relevant parameters, but this oxygen control system has two main problems: the liquid lead-bismuth is highly corrosive, and the thermocouple needs to be protected, increasing the complexity of the system; and the measurement positions of temperature and oxygen concentration are usually inconsistent, making it difficult to achieve simultaneous measurement, which can introduce errors and affect the accuracy of the data. SUMMARY

[0004] The present application provides an oxygen concentration sensor coupled with temperature detection, effectively solving the technical problem of oxygen concentration measurement error caused by inconsistent measurement positions of temperature and oxygen concentration in the existing oxygen control system. The present application uses an embedded thermocouple sleeve to couple the real-time monitoring function of temperature, and uses the thermocouple sleeve and YSZ ceramic tube to achieve simultaneous measurement of temperature and electromotive force, reducing temporal and spatial errors, thereby improving the stability of oxygen concentration data.

[0005] The first object of the present application is to provide an oxygen concentration sensor coupled with temperature detection, comprising a YSZ ceramic tube and a ZrO2 ceramic tube, the YSZ ceramic tube being connected to the end of the ZrO2 ceramic tube and coaxially arranged; further comprising a temperature measurement unit and an electromotive force measurement unit.

[0006] The temperature measurement unit comprises a temperature sensing module and a first signal quick connector, the temperature sensing module being arranged in the ZrO2 ceramic tube, for sensing temperature signals when the temperature sensing module is immersed in the liquid lead-bismuth alloy, and transmitting temperature data through the first signal quick connector.

[0007] The electromotive force measuring unit comprises a Pt electrode, a positive electrode lead, a negative electrode connecting wire and a second signal quick connector, the Pt electrode is arranged in the YSZ ceramic tube and forms a reference electrode with air, the reference electrode is electrically connected with the positive electrode lead, and the negative electrode connecting wire is electrically connected with the YSZ ceramic tube; the oxygen partial pressure difference between the liquid lead-bismuth alloy and the reference electrode is sensed when the YSZ ceramic tube is immersed in the liquid lead-bismuth alloy, and electromotive force data is transmitted through the second signal quick connector; the oxygen concentration is obtained through the Nernst equation according to the synchronous measured temperature data and electromotive force data.

[0008] As a preferred embodiment, the temperature sensing module comprises a thermocouple and a thermowell, the thermowell is sleeved outside the thermocouple and is used for conducting heat to the thermocouple when the thermowell is immersed in the liquid lead-bismuth alloy to sense the temperature signal.

[0009] As a preferred embodiment, the positive electrode lead is a platinum-coated austenitic stainless steel wire with a sharp tip; and the negative electrode connecting wire is a molybdenum wire.

[0010] As a preferred embodiment, the YSZ ceramic tube is yttria-stabilized zirconia ceramic, and the doping amount of yttria is 5mol%-9mol%.

[0011] As a preferred embodiment, the temperature detection range of the oxygen concentration sensor coupled with temperature detection is 400℃-1650℃.

[0012] As a preferred embodiment, the oxygen partial pressure detection range of the oxygen concentration sensor coupled with temperature detection is 10 -24 atm-1atm.

[0013] As a preferred embodiment, the top end of the ZrO2 ceramic tube is provided with a metal shell, the metal shell is provided with a ventilation hole, and the Pt electrode communicates with air through the ventilation hole to form a reference electrode.

[0014] As a preferred embodiment, the ZrO2 ceramic tube is sleeved with a stainless steel sheath, and the stainless steel sheath and the metal shell are sealed by a heat-resistant rubber ring.

[0015] Compared with the prior art, the present application has the following beneficial effects: The application provides a temperature detection coupled oxygen concentration sensor, which comprises a temperature measurement unit composed of a temperature sensing module and a first signal quick connector, the temperature sensing module is used for sensing a temperature signal when the temperature sensing module is immersed in liquid lead-bismuth alloy, and the temperature data is transmitted through the first signal quick connector; an electromotive force measurement unit composed of a Pt electrode, a positive electrode lead, a negative electrode connecting wire and a second signal quick connector, which is used for sensing the oxygen partial pressure difference between the liquid lead-bismuth alloy and the reference electrode when the YSZ ceramic tube is immersed in the liquid lead-bismuth alloy, and the electromotive force data is transmitted through the second signal quick connector; and the temperature data and the electromotive force data are synchronously measured, and the oxygen concentration is obtained through the Nernst equation. In order to realize synchronous measurement, reduce the time-space error and improve the stability of the oxygen concentration data, the temperature measurement unit and the electromotive force measurement unit are integrated. When measuring, the YSZ ceramic tube at the front end of the detector is immersed in the liquid lead-bismuth alloy, the YSZ ceramic tube generates electromotive force through the oxygen partial pressure difference between the liquid lead-bismuth alloy and the Pt electrode, and the electromotive force data is transmitted through the second signal quick connector. The heat is transmitted to the built-in temperature sensing module through the ZrO2 ceramic tube, and the real-time temperature value is obtained through the first signal quick connector. Finally, the real-time measured electromotive force and the synchronous temperature value are substituted into the Nernst equation, and the corresponding oxygen concentration can be calculated.

[0016] Unlike the traditional single-function oxygen sensor, the application adopts the embedded temperature sensing module to couple the real-time detection function of temperature, the synchronous measurement of electromotive force and temperature reduces the time-space error, and is beneficial to improve the stability of the oxygen concentration data. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor.

[0018] Figure 2 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor. Figure 1 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor.

[0019] Figure 3 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor. Figure 1 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor.

[0020] Figure 4 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor. Figure 1 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor.

[0021] Figure 5 The application provides a structural schematic diagram of the temperature detection coupled oxygen concentration sensor.

[0022] Figure 6This is a graph showing the potential and oxygen concentration data detected by the oxygen concentration sensor coupled with temperature detection according to the present invention in a liquid lead-bismuth alloy at 650°C.

[0023] Figure label: 1. YSZ ceramic tube, 2. Pt electrode, 3. ZrO2 ceramic tube, 4. Positive electrode lead, 5. Negative electrode connecting wire, 6. Thermocouple sheath, 7. Fixing clip, 8. Stainless steel sheath, 9. Heat-resistant rubber ring, 10. Vent hole, 11. Metal shell, 12. First signal quick connector, 13. Second signal quick connector, 14. Thermocouple. Detailed Implementation

[0024] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the invention. Unless otherwise specified, the following test methods and detection methods are conventional methods; unless otherwise specified, the reagents and raw materials are commercially available.

[0025] Existing oxygen concentration sensors typically employ a combination of an oxygen sensor and a thermocouple to monitor relevant parameters. However, this method suffers from two main problems: first, liquid lead-bismuth is highly corrosive, requiring additional protection measures for the thermocouple and increasing system complexity; second, the measurement locations for temperature and oxygen concentration are usually inconsistent, making synchronous measurement difficult, easily introducing errors, and affecting data accuracy. To address these technical problems, this invention provides an oxygen concentration sensor coupled with temperature detection.

[0026] The technical solution of the present invention will be described in detail below.

[0027] This invention first provides an oxygen concentration sensor coupled with temperature detection, such as... Figures 1-4 As shown, it includes a YSZ ceramic tube 1 and a ZrO2 ceramic tube 3, wherein the YSZ ceramic tube 1 is connected to the end of the ZrO2 ceramic tube 3 and is coaxially arranged; it also includes a temperature measurement unit and an electromotive force measurement unit.

[0028] The temperature measurement unit includes a temperature sensing module and a first signal quick connector 12 (thermocouple connection signal quick connector). The temperature sensing module is disposed inside the ZrO2 ceramic tube 3 and is used to sense the temperature signal when the temperature sensing module is immersed in liquid lead-bismuth alloy, and to transmit the temperature data through the first signal quick connector 12.

[0029] The electromotive force measurement unit includes a Pt electrode 2, a positive electrode lead 4, a negative electrode connecting wire 5, and a second signal quick connector 13 (oxygen concentration sensor signal quick connector). The Pt electrode 2 is disposed inside the YSZ ceramic tube 1 and forms a reference electrode with the air. The reference electrode is electrically connected to the positive electrode lead 4, and the negative electrode connecting wire 5 is electrically connected to the YSZ ceramic tube 1. It is used to sense the oxygen partial pressure difference between the liquid lead-bismuth alloy and the reference electrode when the YSZ ceramic tube 1 is immersed in liquid lead-bismuth alloy, and to transmit electromotive force data through the second signal quick connector 13. Based on the synchronously measured temperature data and electromotive force data, the oxygen concentration is obtained through the Nernst equation.

[0030] The oxygen concentration sensor for coupled temperature detection includes: a YSZ ceramic tube 1, a Pt electrode 2, a ZrO2 ceramic tube 3, a positive electrode lead 4, a negative electrode connecting wire 5, a thermocouple sheath 6, a first signal quick connector 12, a second signal quick connector 13, and a thermocouple 14. The Pt electrode 2 is disposed inside the YSZ ceramic tube 1 and communicates with external air through the vent 10, forming a Pt-Air reference electrode. The positive electrode lead 4 is disposed inside the ZrO2 ceramic tube 3, and its upper end is connected to an external voltage acquisition device through the second signal quick connector 13. The negative electrode connecting wire 5 is connected to the YSZ ceramic tube 1 at the tip of the ZrO2 ceramic tube 3, forming an electrical signal circuit with the voltage acquisition device. An electromotive force (EMF) is generated by sensing the oxygen partial pressure difference between the liquid lead-bismuth alloy and the Pt electrode 2 through the YSZ ceramic tube 1. This EMF is led out through the circuit formed by the positive electrode lead 4 and the negative electrode connecting wire 5, and the voltage acquisition device acquires the EMF. The oxygen concentration is calculated based on the Nernst equation combined with the EMF and the synchronous temperature value.

[0031] In a preferred embodiment, the temperature sensing module includes a thermocouple 14 and a thermocouple sleeve 6. The thermocouple sleeve 6 is fitted over the thermocouple 14 and is used to conduct heat to the thermocouple 14 when the thermocouple sleeve 6 is immersed in liquid lead-bismuth alloy, thereby sensing a temperature signal. The thermocouple sleeve 6 is disposed inside a ZrO2 ceramic tube 3, and the thermocouple 14 is embedded inside the thermocouple sleeve 6. The thermocouple 14 is connected to an external temperature measuring instrument via a first signal quick connector 12. Heat is conducted to the thermocouple 14 through the thermocouple sleeve 6 directly immersed in liquid lead-bismuth alloy. The thermocouple 14 generates a thermoelectric potential based on the Seebeck effect and transmits it to the external temperature measuring instrument through the first signal quick connector 12 to obtain the temperature value. This invention uses an embedded thermocouple sleeve 6 to couple the real-time temperature detection function. The synchronous measurement of oxygen concentration and temperature reduces spatiotemporal errors and helps improve data stability.

[0032] In a preferred embodiment, the positive electrode lead 4 is an austenitic stainless steel wire with a platinum-plated tip. Platinum is a precious metal with excellent chemical inertness and conductivity. Its main function is to firmly seal the air (reference gas) inside the YSZ ceramic tube 1, preventing it from exchanging or contaminating with the external measured medium (a highly corrosive lead-bismuth alloy). As a reference electrode, it efficiently and stably extracts the electrode signal from the inner wall (air side) of the YSZ ceramic tube 1, forming a complete measurement circuit. The negative electrode connecting wire 5 is a molybdenum wire. The molybdenum wire is used to connect to the tip of the YSZ ceramic tube 1 (i.e., the working electrode end), forming a complete oxygen measurement circuit with the positive electrode lead 4. The electrode lead does not interact with the electrode material, is stable within the measured oxygen partial pressure range, and can be a good electronic conductor; stainless steel wire, Pt wire, or tungsten wire can be selected. Molybdenum wire has good corrosion resistance in liquid lead-bismuth.

[0033] In a preferred embodiment, the YSZ ceramic tube 1 is a yttrium oxide-stabilized zirconia ceramic with a yttrium oxide doping amount of 5 mol% to 9 mol%. The yttrium oxide doping amount is crucial to the performance of the YSZ ceramic tube. When the doping amount is 9%, the system exhibits the highest ionic conductivity, resulting in faster response speed and higher sensitivity in applications. However, the introduction of Y₂O₃ typically reduces the mechanical strength of the material. Therefore, in practical applications, a balance must be struck between ionic conductivity and mechanical strength. The Y₂O₃ content can be adjusted according to different needs to obtain an electrolyte matrix with good mechanical strength and ionic conductivity. The YSZ ceramic tube 1, as the core solid electrolyte, is used to conduct oxygen ions and generate an electromotive force.

[0034] In a preferred embodiment, the oxygen concentration sensor for coupled temperature detection has a detection temperature range of 400℃ to 1650℃. This detection temperature range is primarily determined by the oxygen partial pressure detection range of the oxygen concentration sensor. The YSZ ceramic tube 1 material exhibits good accuracy in measuring oxygen partial pressure within the 400℃ to 1650℃ range.

[0035] In a preferred embodiment, the oxygen partial pressure detection range of the oxygen concentration sensor coupled with temperature detection is 10. -24 The oxygen partial pressure measurement range is determined by the material of the YSZ ceramic tube 1 used in this invention, and is derived from the range of stable potential difference formed by ion exchange within it.

[0036] In a preferred embodiment, a metal shell 11 is provided at the top end of the ZrO2 ceramic tube 3. A vent 10 is provided on the metal shell 11, through which the Pt electrode 2 communicates with the air, forming a reference electrode. The metal shell 11 is connected to the top end of the ZrO2 ceramic tube 3 by a fixing clip 7. To provide overall mechanical protection and structural framework for the oxygen concentration sensor coupled with temperature detection of the present invention, and to accommodate the internal components, the present invention also provides a metal shell 11 for overall protection of the device. The metal shell 11 has a vent 10, through which the Pt electrode 2 communicates with the air, forming a reference electrode. Since the Pt electrode 2 needs to be connected to the external air to form the Pt-Air reference electrode, which is the reference terminal of the entire oxygen measurement electrochemical circuit, this invention opens a vent 10 on the metal shell 11 to connect the Pt electrode to the air. The partial pressure of oxygen in the air is known and stable. The Pt electrode catalyzes the reduction reaction of oxygen here, providing a constant and known oxygen partial pressure for one side of the YSZ ceramic tube 1. The other side of the YSZ ceramic tube 1 (through the tip of the YSZ ceramic tube 1) is exposed to the liquid lead-bismuth alloy to be measured, sensing the oxygen partial pressure therein. Due to the difference in oxygen partial pressure on both sides, oxygen ions migrate through the YSZ ceramic tube 1, thereby generating an electromotive force on the Pt electrodes on both sides. This electromotive force is led out through a circuit formed by the positive electrode lead 4 and the negative electrode connecting wire 5, and measured by an external voltage acquisition device. Finally, according to the Nernst equation, the measured temperature value and electromotive force are introduced into the Nernst equation to calculate the oxygen concentration in the liquid lead-bismuth alloy.

[0037] In order to serve as a buffer, seal and heat insulation, the ZrO2 ceramic tube 3 of the present invention is covered with a stainless steel sheath 8, and the stainless steel sheath 8 is sealed to the metal outer shell 11 by a heat-resistant rubber ring 9.

[0038] Experimental results and verification of physical effects Figure 5 This is a graph showing the potential and oxygen concentration data detected by the oxygen concentration sensor coupled with temperature detection according to the present invention in a liquid lead-bismuth alloy at 600°C. Figure 5 It can be seen that the oxygen concentration corresponding to the liquid lead-bismuth alloy at 600℃ is 1×10⁻⁶. -6 The results showed that under continuous high-temperature exposure for eight days, the probe's potential signal remained at an extremely stable level without significant drift or fluctuation. This performance indicates that the probe possesses excellent chemical and electrochemical stability in the high-temperature lead-bismuth system, enabling it to reliably reflect the oxygen content in the alloy melt over a long period. Its stable output also verifies the good tolerance of the probe's materials and structure to complex corrosive environments, providing important evidence for its subsequent online detection applications in practical systems.

[0039] Figure 6This is a graph showing the potential and oxygen concentration data detected by the oxygen concentration sensor coupled with temperature detection according to the present invention in a liquid lead-bismuth alloy at 650°C. Figure 6 It can be seen that the oxygen concentration corresponding to the liquid lead-bismuth alloy at 650℃ is 5×10⁻⁶. -7 The results showed that under four consecutive days of high-temperature exposure, the probe's potential signal remained extremely stable without significant drift or fluctuation. This performance indicates that the probe possesses excellent chemical and electrochemical stability in the high-temperature lead-bismuth system, enabling it to reliably reflect the oxygen content of the melt over a long period. Its stable output also verifies the good tolerance of the probe's materials and structure to complex corrosive environments, providing important evidence for its subsequent online detection applications in practical systems.

[0040] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An oxygen concentration sensor coupled with temperature detection, comprising a YSZ ceramic tube (1) and a ZrO2 ceramic tube (3), wherein the YSZ ceramic tube (1) is connected to the end of the ZrO2 ceramic tube (3) and is coaxially arranged; characterized in that, It also includes a temperature measurement unit and an electromotive force measurement unit; The temperature measurement unit includes a temperature sensing module and a first signal quick connector (12). The temperature sensing module is set inside the ZrO2 ceramic tube (3) and is used to sense the temperature signal when the temperature sensing module is immersed in the liquid lead-bismuth alloy, and to transmit the temperature data through the first signal quick connector (12). The electromotive force measurement unit includes a Pt electrode (2), a positive electrode lead (4), a negative electrode connecting wire (5), and a second signal quick connector (13). The Pt electrode (2) is placed inside the YSZ ceramic tube (1) and forms a reference electrode with the air. The reference electrode is electrically connected to the positive electrode lead (4), and the negative electrode connecting wire (5) is electrically connected to the YSZ ceramic tube (1). It is used to sense the oxygen partial pressure difference between the liquid lead-bismuth alloy and the reference electrode when the YSZ ceramic tube (1) is immersed in the liquid lead-bismuth alloy, and to transmit the electromotive force data through the second signal quick connector (13). Based on the synchronously measured temperature data and electromotive force data, the oxygen concentration is obtained through the Nernst equation.

2. The oxygen concentration sensor with coupled temperature detection according to claim 1, characterized in that, The temperature sensing module includes a thermocouple (14) and a thermocouple sleeve (6). The thermocouple sleeve (6) is fitted over the outside of the thermocouple (14) and is used to conduct heat to the thermocouple (14) when the thermocouple sleeve (6) is immersed in liquid lead-bismuth alloy, so as to sense the temperature signal.

3. The oxygen concentration sensor coupled with temperature detection according to claim 1, characterized in that, The positive electrode lead (4) is an austenitic stainless steel wire with a platinum-plated tip; the negative electrode connecting wire (5) is a molybdenum wire.

4. The oxygen concentration sensor with coupled temperature detection according to claim 1, characterized in that, The YSZ ceramic tube (1) is a yttrium oxide-stabilized zirconia ceramic with a yttrium oxide doping amount of 5 mol% to 9 mol%.

5. The oxygen concentration sensor with coupled temperature detection according to claim 1, characterized in that, The temperature detection range of the oxygen concentration sensor coupled with temperature detection is 400℃~1650℃.

6. The oxygen concentration sensor coupled with temperature detection according to claim 1, characterized in that, The oxygen partial pressure detection range of the oxygen concentration sensor coupled with temperature detection is 10. -24 atm~1atm.

7. The oxygen concentration sensor coupled with temperature detection according to claim 1, characterized in that, The top end of the ZrO2 ceramic tube (3) is provided with a metal shell (11), and a vent hole (10) is provided on the metal shell (11). The Pt electrode (2) is connected to the air through the vent hole (10) to form a reference electrode.

8. The oxygen concentration sensor with coupled temperature detection according to claim 7, characterized in that, The ZrO2 ceramic tube (3) is fitted with a stainless steel sheath (8), and the stainless steel sheath (8) is sealed to the metal shell (11) by a heat-resistant rubber ring (9).

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