Loop-type oxygen concentration sensor for liquid lead bismuth circulation loop and testing method of loop-type oxygen concentration sensor

Abstract

The invention discloses a loop type oxygen concentration sensor for a liquid lead bismuth circulation loop, which is characterized in that the lower end of a concentrated positive electrode lead is inserted into a reference electrode, and the reference electrode is fixed with a straight-through clamping sleeve; the positive electrode lead is arranged in the center of the electrode side protection steel sleeve, the electrode side protection steel sleeve and the straight-through side protection steel sleeve are connected with the reducing clamping sleeve through threads from the upper portion and the lower portion respectively, and the lower end of the electrode side protection steel sleeve is connected with the straight-through clamping sleeve through threads. Solid oxide electrolyte is arranged in the electrode side protection steel sleeve, and an insulating sleeve is arranged in the straight-through side protection steel sleeve. Compared with a common loop type oxygen concentration sensor, the liquid lead bismuth oxygen concentration sensor is more suitable for directly measuring the oxygen concentration at a pipeline in a liquid lead bismuth circulation loop. The reference electrode adopts LSCF powder, and in previous tests, the lowest working temperature is 200 DEG C, so that various requirements are met.

Description

Technical Field

[0001] The invention belongs to the technical field of oxygen concentration sensing, and in particular relates to a loop type oxygen concentration sensor for a liquid lead-bismuth circulation loop. Background Art

[0002] Liquid lead-bismuth alloy has many advantages such as low melting point, high boiling point, good neutronic properties, thermal conductivity and radiation resistance, and is considered to be the preferred material for the coolant of the fourth-generation reactor lead-based fast reactor. Liquid lead-bismuth alloy has strong corrosion to structural materials at high temperatures. Studies have shown that reasonable control of the oxygen concentration of lead and bismuth can make the structural materials form a dense oxide film, thereby inhibiting the corrosion of liquid lead-bismuth alloy to structural materials. Summary of the invention

[0003] In view of the problems existing in the background technology, the present invention provides a loop type oxygen concentration sensor for a liquid lead-bismuth circulation loop, and provides a loop type oxygen concentration sensor for a liquid lead-bismuth circulation loop, which can perform certain high temperature and high pressure tests on the loop type oxygen concentration sensor for the liquid lead-bismuth circulation loop to meet subsequent application requirements. The technical solution includes: a straight-through ferrule, a reducing ferrule, an electrode side protective steel sleeve, a straight-through side protective steel sleeve, a solid oxide electrolyte, an inner insulating tube, a positive electrode lead and a reference electrode, wherein the lower end of the positive electrode lead is inserted into the reference electrode, and the reference electrode is fixed to the straight-through ferrule;

[0004] The positive electrode lead is arranged in the center of the straight-through side protection steel sleeve, the electrode side protection steel sleeve and the straight-through side protection steel sleeve are respectively connected to the reducer sleeve through threads from the top and bottom, and the lower end of the electrode side protection steel sleeve is connected to the straight-through sleeve through threads; a solid oxide electrolyte is arranged in the electrode side protection steel sleeve, a solid oxide electrolyte is arranged inside the electrode side protection steel sleeve, and an insulating sleeve is arranged inside the straight-through side protection steel sleeve.

[0005] The solid oxide electrolyte and the electrode side protective steel sleeve are fixed by an internal high temperature resistant ceramic sealant, and a gap for the flow of lead and bismuth is reserved between the solid oxide electrolyte and the electrode side protective steel sleeve.

[0006] The material used for the reference electrode is LSCF, which is in powder form, has a particle size of 5 to 10 μm, and a purity of 99.9%.

[0007] The straight-through ferrule is sealed with a stainless steel reactor or a test pipe, and the liquid lead-bismuth alloy and the solid oxide electrolyte, the reference electrode, the negative electrode lead, the positive electrode lead, and the voltage signal collection terminal form a complete primary battery circuit, and the voltage signal collection terminal is connected to a voltmeter.

[0008] The material used for the negative electrode lead and the positive electrode lead is 316L with a purity of 99.9%.

[0009] The voltage signal acquisition terminal is connected to the computer display signal, and a high input resistance voltage acquisition card greater than 10GΩ is used.

[0010] A test method for a loop oxygen concentration sensor for a liquid lead-bismuth circulation loop is also provided, and the technical solution includes:

[0011] Step 1: Initial preparation;

[0012] Step 2: Close the exhaust valve of melting tank No. 1 and the air inlet valve of melting tank No. 2 to prevent gas from flowing into or out of the test system;

[0013] Step 3, start heating wire heating: start the heating wire heating system, provide heat by winding the heating wire, keep the lead-bismuth alloy in the main pipeline in a liquid flow state, and activate the loop oxygen concentration sensor in the pipeline above 300°C:

[0014] Step 4, injecting argon gas to fill the main pipeline with lead and bismuth: open the air inlet valve of the No. 1 melting tank, and pass argon gas into the No. 1 melting tank. The pressure of the argon gas will push the liquid lead and bismuth in the No. 1 melting tank into the No. 1 liquid metal valve and the main pipeline until the main pipeline is filled with lead and bismuth;

[0015] Step 5, liquid lead and bismuth flow to melting tank No. 2: gradually open the liquid metal valve No. 2, and flow to melting tank No. 2 through the main pipeline;

[0016] Step 6, adjusting the flow rate of lead-bismuth alloy: after the main pipeline is filled, continue to adjust the pressure of argon gas to control the pressure in the No. 1 melting tank to adjust the flow rate of the lead-bismuth alloy so that it circulates in the main pipeline at a set stable flow rate;

[0017] Step 7, test start: When the flow rate of lead and bismuth is stable, start measuring and testing the loop oxygen concentration sensor signal, record the response data of the loop oxygen concentration sensor, and observe the working performance of the sensor under different conditions; the minimum working temperature is 200°C;

[0018] Step 8. After the test experiment is completed, open the No. 1 liquid metal valve, the No. 2 liquid metal valve, the No. 1 melting tank exhaust valve and the No. 2 melting tank exhaust valve, and the liquid lead and bismuth are recovered into the No. 1 melting tank and the No. 2 melting tank due to gravity.

[0019] The step 1 comprises:

[0020] Step 11, establish a test system: fix the two ends of the inverted U-shaped main pipeline to the center of the flanges of the No. 1 melting tank and the No. 2 melting tank respectively through the No. 1 liquid metal valve and the No. 2 liquid metal valve; the flange of the No. 1 melting tank is also provided with a pipeline connected to the exhaust port through the No. 1 melting tank exhaust valve, and a pipeline connected to the air inlet through the pressure sensor and the No. 1 melting tank intake valve, and the flange of the No. 2 melting tank is also provided with a pipeline connected to the exhaust port through the No. 2 melting tank exhaust valve, and a pipeline connected to the air inlet through the No. 2 melting tank intake valve, a thermocouple is installed on the main pipeline, and at the same time, multiple embodiments of the loop type oxygen concentration sensor are fixed to the pipe wall of the main pipeline through a reducing sleeve, and the reference electrode of each loop type oxygen concentration sensor extends into the main pipeline;

[0021] Step 12, installing loop type oxygen concentration sensors: installing multiple loop type oxygen concentration sensors on the main pipeline, and the test will monitor the signal of the sensor;

[0022] Step 13, filling the melting tank with alloy: melting tank No. 1 and melting tank No. 2 are filled with liquid lead-bismuth alloy that meets the experimental requirements; the lead-bismuth loading amount of melting tank No. 1 and melting tank No. 2 must meet the requirement of uninterrupted flow during the experimental time;

[0023] Step 14: Install the heating wire heating system: The heating wire heating system wrapped around the main pipeline is used to maintain the temperature of the lead and bismuth in the pipeline to prevent it from solidifying.

[0024] In step 7, the air space pressure of the No. 1 melting tank and the temperature of the liquid lead-bismuth alloy in the main pipeline are adjusted to test the sealing performance of the loop-type oxygen concentration sensor under different pressure and temperature conditions; during the entire test process, it is ensured that the flow state of the lead-bismuth alloy is controlled under constant temperature and pressure conditions, so that the response of the loop-type oxygen concentration sensor can be accurately measured.

[0025] The beneficial effects of the present invention are:

[0026] 1. A loop oxygen concentration sensor is designed. Compared with the general loop oxygen concentration sensor, it is more suitable for the liquid lead-bismuth circulation loop and directly measures the oxygen concentration in the pipeline. The reference electrode uses LSCF powder. In the previous test, the minimum operating temperature is 200℃, which meets all the requirements.

[0027] 2. Designed a matching test method to meet the testing requirements of working environment temperature and different temperatures and pressures in the pipeline.

[0028] 3. The oxygen ion electromotive force is intuitively obtained through a high input resistance (>10GΩ) voltmeter, and the dissolved oxygen concentration of the liquid lead-bismuth alloy system is obtained by solving the Nernst equation, which can monitor the dissolved oxygen concentration of the liquid lead-bismuth alloy coolant system in real time.

[0029] 4. A loop type oxygen concentration sensor for a liquid lead-bismuth circulation loop and a sealing test scheme for this type of loop type oxygen concentration sensor are provided. The protective steel sleeve consisting of an upper straight-through side protective steel sleeve and a middle and lower electrode side protective steel sleeve is convenient for installation and movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a schematic flow chart of an embodiment of a loop oxygen concentration sensor for a liquid lead-bismuth circulation loop.

[0031] Figure 2 Schematic diagram of the structure of the test system in the embodiment of the present invention.

[0032] Among them, 1-positive electrode lead, 2-insulating sleeve, 3-reducing ferrule, 5-solid oxide electrolyte, 6-straight-through ferrule, 7-reference electrode, 8-No. 1 melting tank, 9-No. 2 melting tank, 10-No. 1 melting tank air inlet valve, 11-pressure sensor, 12-No. 1 melting tank exhaust valve, 13-No. 2 melting tank air inlet valve, 14-No. 2 melting tank exhaust valve, 15-No. 1 liquid metal valve, 16-No. 2 liquid metal valve, 17-thermocouple, 18-loop oxygen concentration sensor, 19-winding heating wire, 20-main pipeline, 41-straight-through side protection steel sleeve, 42-electrode side protection steel sleeve. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0034] like Figure 1 The loop type oxygen concentration sensor 18 provided by the embodiment of the present invention shown in the figure comprises: a straight-through ferrule 6, a reducing ferrule 3, a straight-through side protective steel sleeve 41, an electrode side protective steel sleeve 42, a solid oxide electrolyte 5, an inner insulating tube 2, a positive electrode lead 1 and a reference electrode 7, wherein the lower end of the positive electrode lead 1 is inserted into the reference electrode 7, and the reference electrode 7 is fixed to the straight-through ferrule 6;

[0035] The positive electrode lead 1 is arranged in the center of the electrode side protection steel sleeve 42. The electrode side protection steel sleeve 42 and the straight-through side protection steel sleeve 41 are connected to the reducer sleeve 3 through threads from the top and bottom respectively. The lower end of the electrode side protection steel sleeve 42 is connected to the straight-through sleeve 6 through threads; the inner upper ends of the reducer sleeve 3 are provided with steps inwardly for installing the straight-through side protection steel sleeve 41 (outside) and the insulating sleeve 2 (inside); a solid oxide electrolyte 5 is arranged in the electrode side protection steel sleeve 42, and an insulating sleeve 2 is installed in the upper part of the straight-through side protection steel sleeve 41. The insulating sleeve 2 is used to avoid short circuit caused by contact with the stainless steel shell.

[0036] During installation, the straight-through ferrule 6 is used to seal the stainless steel reactor (or pipeline), and the actual loop operating conditions are simulated by adjusting the PID temperature control and the pressure sensor pressure control to debug and test the loop sensor. When the embodiment is inserted into the test device, the liquid lead-bismuth alloy forms a complete primary battery circuit with the solid oxide electrolyte, the reference electrode, the negative electrode lead (not shown in the figure), the positive electrode lead, and the voltage signal acquisition terminal, and the voltage signal acquisition terminal is connected to the voltmeter.

[0037] The material used for the reference electrode 7 is LSCF, which is in powder form, has a particle size of 5 to 10 μm, and a purity of 99.9%.

[0038] The material used for the negative electrode lead and the positive electrode lead is 316L with a purity of 99.9%.

[0039] The voltage signal acquisition terminal is connected to the computer display signal, and a high input resistance (>10GΩ) voltage acquisition card is used.

[0040] The solid oxide electrolyte 5 and the electrode side protective steel sleeve 42 are fixed by an internal high temperature resistant ceramic sealant. The gap between the solid oxide electrolyte and the protective steel sleeve is reserved for lead bismuth. The liquid lead bismuth alloy flows outward through the gap, but due to the air cooling outside the electrode side protective steel sleeve 42, the liquid lead bismuth solidifies in the gap part, thereby preventing the internal lead bismuth from overflowing outward.

[0041] The PID temperature control of the auxiliary accessories is used to test the sealing effect of the loop oxygen concentration sensor under different temperature conditions by adjusting different liquid lead and bismuth temperatures.

[0042] Step 1: Initial preparation, including:

[0043] Step 11: Create Figure 2 The test system shown: the two ends of the inverted U-shaped main pipeline are fixed to the center of the flanges of the No. 1 melting tank 8 and the No. 2 melting tank 9 through the No. 1 liquid metal valve and the No. 2 liquid metal valve 16 respectively; the flange of the No. 1 melting tank 8 is also provided with a pipeline connected to the exhaust port through the No. 1 melting tank exhaust valve 12, and a pipeline connected to the air inlet through the pressure sensor 11 and the No. 1 melting tank intake valve 10, and the flange of the No. 2 melting tank 9 is also provided with a pipeline connected to the exhaust port through the No. 2 melting tank exhaust valve 14, and a pipeline connected to the air inlet through the No. 2 melting tank intake valve 13, a thermocouple 17 is installed on the main pipeline 20, and multiple embodiments of the loop type oxygen concentration sensor 18 are fixed to the pipe wall of the main pipeline 20 through the reducer ferrule 3, and the reference electrode 7 of each loop type oxygen concentration sensor 18 extends into the main pipeline 20;

[0044] Step 12: Install the loop type oxygen concentration sensor: install a plurality of loop type oxygen concentration sensors 18 on the main pipeline 20. The test will monitor the signal of the sensor.

[0045] Step 13, filling the melting tank with alloy: melting tank No. 1 8 and melting tank No. 2 9 are filled with liquid lead-bismuth (Pb-Bi) alloy that meets the experimental requirements; the lead-bismuth loading in melting tank No. 1 8 and melting tank No. 2 9 must meet the requirement of uninterrupted flow during the experimental time.

[0046] Step 14: Install the heating wire heating system 19: The heating wire heating system 19 wound around the main pipeline 20 is used to maintain the temperature of the lead and bismuth in the pipeline to prevent them from solidifying.

[0047] Step 2: Close the exhaust valve 12 of the No. 1 melting tank and the air inlet valve 13 of the No. 2 melting tank to prevent gas from flowing into or out of the test system.

[0048] Step 3, start heating wire heating: start heating wire heating system 19, provide heat by winding heating wire, keep the lead-bismuth alloy in the main pipeline in liquid flow state; this step is used to activate the loop type oxygen concentration sensor in the pipeline: the sealing of the loop type oxygen concentration sensor mainly depends on the low melting point characteristics of liquid lead-bismuth, and the sealing effect is achieved by solidifying lead-bismuth. In addition, the principle of electrochemical primary cell is that the electromotive force is generated due to the different oxygen concentrations of cathode and anode on both sides of the solid oxide electrolyte. The electromotive force on both sides is measured to obtain the oxygen concentration in the liquid lead-bismuth alloy; the loop type oxygen concentration sensor solid oxide electrolyte of the loop type oxygen concentration sensor and its test device for the liquid lead-bismuth circulation loop needs to be activated above 300°C, and the minimum operating temperature is 200°C.

[0049] Step 4, inject argon to fill the main pipeline with lead and bismuth: open the air inlet valve 10 of the No. 1 melting tank, and pass argon into the No. 1 melting tank 8. The pressure of the argon will push the liquid lead and bismuth in the No. 1 melting tank to pass into the No. 1 liquid metal valve 15 and the main pipeline 20 until the main pipeline 20 is full of lead and bismuth. At this time, the No. 2 liquid metal valve 16 is in a closed state; as the liquid lead and bismuth are pressed into the main pipeline and filled, the experiment enters the next stage.

[0050] Step 5, liquid lead and bismuth flow to melting tank No. 2: gradually open liquid metal valve No. 2 16 and flow to melting tank No. 2 9 through main pipeline 20.

[0051] Step 6, adjusting the flow rate of lead-bismuth alloy: after the main pipeline is filled, continue to adjust the pressure of argon gas to control the pressure in the No. 1 melting tank to adjust the flow rate of the lead-bismuth alloy so that it circulates in the main pipeline at a set stable flow rate;

[0052] Step 7, test start: When the flow rate of lead-bismuth stabilizes, start measuring and testing the signal of the loop oxygen concentration sensor, record the response data of the loop oxygen concentration sensor, and observe the working performance of the sensor under different conditions; specifically, by adjusting the air space pressure of the No. 1 melting tank and the temperature of the liquid lead-bismuth alloy in the main pipeline, test the sealing of the loop oxygen concentration sensor under different pressure and temperature conditions. During the entire test process, it is ensured that the flow state of the lead-bismuth alloy is controllable under constant temperature and pressure conditions, so that the response of the loop oxygen concentration sensor can be accurately measured.

[0053] Step 8. After the test experiment is completed, open the liquid metal valves No. 1 and No. 2, the exhaust valve 12 of the melting tank No. 1, and the exhaust valve 14 of the melting tank No. 2, and the liquid lead and bismuth are recovered into the melting tank No. 1 and the melting tank No. 2 due to gravity.

[0054] The test process in step 7 explains in detail how to use argon pressure to promote the flow of liquid lead-bismuth, and combine it with the heating wire heating system to ensure that the flow and temperature conditions of lead-bismuth in the experiment meet the test requirements.

Claims

1. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop, characterized in that: include: A straight-through ferrule (6), a reducing ferrule (3), a straight-through side protective steel sleeve (41), an electrode side protective steel sleeve (42), a solid oxide electrolyte (5), an inner insulating tube (2), a positive electrode lead (1) and a reference electrode (7), wherein the lower end of the positive electrode lead (1) is inserted into the reference electrode (7), and the reference electrode (7) is fixed to the straight-through ferrule (6); The positive electrode lead (1) is arranged at the center of the through-side protective steel sleeve; the electrode side protective steel sleeve (42) and the through-side protective steel sleeve (41) are respectively connected to the reducing sleeve (3) from the top and bottom through threads; the lower end of the electrode side protective steel sleeve (42) is connected to the through-side sleeve (6) through threads; a solid oxide electrolyte (5) is arranged in the electrode side protective steel sleeve (42); the solid oxide electrolyte (5) is arranged inside the electrode side protective steel sleeve; and an insulating sleeve (2) is arranged inside the through-side protective steel sleeve.

2. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to claim 1, characterized in that: The solid oxide electrolyte (5) and the electrode side protective steel sleeve (41) are fixed by an internal high temperature resistant ceramic sealant, and a gap for the flow of lead and bismuth is reserved between the solid oxide electrolyte and the electrode side protective steel sleeve.

3. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to claim 1, characterized in that: The material used for the reference electrode (7) is LSCF, which is in powder form, has a particle size of 5 to 10 μm, and a purity of 99.9%.

4. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to any one of claims 1 to 3, characterized in that: The straight-through ferrule (6) is sealed with a stainless steel reactor or a test pipe, and the liquid lead-bismuth alloy and the solid oxide electrolyte, the reference electrode, the negative electrode lead, the positive electrode lead, and the voltage signal collection end form a complete primary battery circuit, and the voltage signal collection end is connected to a voltmeter.

5. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to claim 4, characterized in that: The material used for the negative electrode lead and the positive electrode lead is 316L with a purity of 99.9%.

6. A loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to claim 4, characterized in that: The voltage signal acquisition terminal is connected to the computer display signal, and a resistance voltage acquisition card greater than 10GΩ is used.

7. A method for testing a loop oxygen concentration sensor for a liquid lead-bismuth circulation loop as claimed in claim 1, characterized in that: include: Step 1: Initial preparation; Step 2: Close the exhaust valve of melting tank No. 1 and the air inlet valve of melting tank No. 2 to prevent gas from flowing into or out of the test system; Step 3, start heating wire heating: start the heating wire heating system, provide heat by winding the heating wire, keep the lead-bismuth alloy in the main pipeline in a liquid flow state, and activate the loop oxygen concentration sensor in the pipeline above 300°C: Step 4, injecting argon gas to fill the main pipeline with lead and bismuth: open the air inlet valve of the No. 1 melting tank, and pass argon gas into the No. 1 melting tank. The pressure of the argon gas will push the liquid lead and bismuth in the No. 1 melting tank into the No. 1 liquid metal valve and the main pipeline until the main pipeline is filled with lead and bismuth; Step 5, liquid lead and bismuth flow to melting tank No. 2: gradually open the liquid metal valve No. 2, and flow to melting tank No. 2 through the main pipeline; Step 6, adjusting the flow rate of lead-bismuth alloy: after the main pipeline is filled, continue to adjust the pressure of argon gas to control the pressure in the No. 1 melting tank to adjust the flow rate of the lead-bismuth alloy so that it circulates in the main pipeline at a set stable flow rate; Step 7, test start: When the flow rate of lead and bismuth is stable, start measuring and testing the loop oxygen concentration sensor signal, record the response data of the loop oxygen concentration sensor, and observe the working performance of the sensor under different conditions; the minimum working temperature is 200°C; Step 8. After the test experiment is completed, open the No. 1 liquid metal valve, the No. 2 liquid metal valve, the No. 1 melting tank exhaust valve and the No. 2 melting tank exhaust valve, and the liquid lead and bismuth are recovered into the No. 1 melting tank and the No. 2 melting tank due to gravity.

8. The method for testing a loop oxygen concentration sensor for a liquid lead-bismuth circulation loop according to claim 7, characterized in that: The step 1 comprises: Step 11, establish a test system: fix the two ends of the inverted U-shaped main pipeline to the center of the flanges of the No. 1 melting tank and the No. 2 melting tank respectively through the No. 1 liquid metal valve and the No. 2 liquid metal valve; the flange of the No. 1 melting tank is also provided with a pipeline connected to the exhaust port through the No. 1 melting tank exhaust valve, and a pipeline connected to the air inlet through the pressure sensor and the No. 1 melting tank intake valve, and the flange of the No. 2 melting tank is also provided with a pipeline connected to the exhaust port through the No. 2 melting tank exhaust valve, and a pipeline connected to the air inlet through the No. 2 melting tank intake valve, a thermocouple is installed on the main pipeline, and at the same time, multiple embodiments of the loop type oxygen concentration sensor are fixed to the pipe wall of the main pipeline through a reducing sleeve, and the reference electrode of each loop type oxygen concentration sensor extends into the main pipeline; Step 12, installing loop type oxygen concentration sensors: installing multiple loop type oxygen concentration sensors on the main pipeline, and the test will monitor the signal of the sensor; Step 13, filling the melting tank with alloy: melting tank No. 1 and melting tank No. 2 are filled with liquid lead-bismuth alloy that meets the experimental requirements; the lead-bismuth loading amount of melting tank No. 1 and melting tank No. 2 must meet the requirement of uninterrupted flow during the experimental time; Step 14: Install the heating wire heating system: The heating wire heating system wrapped around the main pipeline is used to maintain the temperature of the lead and bismuth in the pipeline to prevent it from solidifying.

9. According to the test method of a loop oxygen concentration sensor for a liquid lead-bismuth circulation loop as described in claim 7, in said step 7, by adjusting the air space pressure of the No. 1 melting tank and the temperature of the liquid lead-bismuth alloy in the main pipeline, the sealing performance of the loop oxygen concentration sensor under different pressure and temperature conditions is tested; during the entire test process, it is ensured that the flow state of the lead-bismuth alloy is controlled under constant temperature and pressure conditions, so that the response of the loop oxygen concentration sensor can be accurately measured.

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