Piston type energy accumulator leakage on-line monitoring device and monitoring method

Abstract

The invention relates to the field of nuclear power maintenance, in particular to a method for measuring the content of depleted zinc in a nuclear power plant boron system.The device comprises a temperature sensor, a phased array ultrasonic probe, a detection host, a pressure sensor and a computer, and the temperature sensor and the phased array ultrasonic probe are installed on the outer wall of the cylindrical surface of an energy accumulator; the temperature sensor and the phased array ultrasonic probe are electrically connected with the detection host respectively, the detection host receives signals of the temperature sensor and the phased array ultrasonic probe and converts the signals into digital signals, and the detection host transmits the digital signals to the computer; and the pressure sensor is arranged on the energy accumulator and transmits a pressure signal to the computer. The monitoring range is wide, the position detection precision is high, the detection error is not larger than + / -3mm, continuous monitoring of the position of the piston of the energy accumulator can be achieved, the gas leakage amount is calculated, and leakage alarm is given.

Description

Technical Field

[0001] The invention relates to the field of nuclear power maintenance, and in particular to an online monitoring device and a monitoring method for leakage of a piston accumulator. Background Art

[0002] Piston accumulators are hydraulic auxiliary energy storage components, which are often used in the hydraulic systems of large valve actuators in nuclear power plants to absorb hydraulic shocks, eliminate pulsation, reduce noise, and ensure smooth transition of the hydraulic system during power transmission. During the long-term operation of the power plant, piston accumulators may leak or cause oil leakage due to failures such as seal damage, resulting in drastic fluctuations in hydraulic oil pressure, threatening the safety of other equipment, and even causing the safety valve to trip, affecting the normal operation of the power plant.

[0003] In the prior art, the accumulators of nuclear power plants do not have devices to indicate the position of the piston, and the operation of the entire system is monitored only by monitoring the oil pressure and setting upper and lower limits. This method has few monitoring points and is limited to extreme position conditions that may threaten the safety of the equipment. It is not conducive to timely discovery and elimination of hidden dangers and has a high safety risk. Summary of the invention

[0004] The present invention provides an online monitoring device and method for leakage of a piston accumulator, which are used to solve the problem in the prior art that the accumulator of a nuclear power plant lacks monitoring equipment and has hidden danger risks.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention proposes an online monitoring device for piston accumulator leakage, which includes a temperature sensor, a phased array ultrasonic probe, a detection host, a pressure sensor and a computer. The temperature sensor and the phased array ultrasonic probe are installed on the outer wall of the cylindrical surface of the accumulator, and the temperature sensor and the phased array ultrasonic probe are electrically connected to the detection host respectively. The detection host receives the signals of the temperature sensor and the phased array ultrasonic probe and converts them into digital models, and the detection host transmits the digital signals to the computer; the pressure sensor is arranged on the accumulator, and the pressure sensor transmits the pressure signal to the computer.

[0007] In some embodiments, the detection host and the pressure sensor transmit signals to the computer via a data line, Ethernet or WIFI.

[0008] In some embodiments, a device health management platform is provided on the computer, and the device health management platform performs calculation, judgment, monitoring and alarm by comparing the initial state parameters of the accumulator after pre-charging with gas and the measurement parameters of the detection host and the pressure sensor.

[0009] The present invention proposes an online monitoring method for piston accumulator leakage, the method comprising:

[0010] Step 1: After the accumulator is pre-charged with gas, the initial state parameters of the accumulator are detected and recorded;

[0011] Step 2: Enter the initial status parameters and alarm thresholds in the equipment health management platform;

[0012] Step 3: When the accumulator is running, the temperature sensor collects the gas temperature T1 in real time, and the pressure sensor collects the oil pressure p in real time 油1 , the phased array ultrasonic probe collects the actual position L1 of the piston in the accumulator in real time;

[0013] Step 4: The equipment health management platform receives the gas temperature T1 and oil pressure p 油1 and the actual piston position L1 data, and calculate the theoretical piston position value L′1, the high alarm value L upper_limit , low alarm value L lower_limit And the safety valve opening alarm value L set ;

[0014] Step 5: The equipment health management platform compares the actual value L1 of the piston position with the theoretical value L′1 and the high alarm value L upper_limit , low alarm value L lower_limit and the alarm value L set Comparison and judgment are made to identify accumulator gas leakage, oil pressure alarm and accumulator opening alarm.

[0015] In some embodiments, the initial state parameters in step 1 include the initial gas pressure p 气0 , initial gas temperature T0 and initial piston position L0.

[0016] In some embodiments, the alarm threshold in step 2 is queried from the maintenance manual, including the oil pressure upper limit p upper_limit , oil pressure lower limit p lower_limit , the safety valve releases the oil pressure p set .

[0017] In some embodiments, the theoretical value L′1 of the piston position in step 4 is calculated according to formula (1);

[0018]

[0019] Low alarm value L lower_limit Calculated according to formula (2);

[0020]

[0021] High alarm value L upper_limit Calculated according to formula (3);

[0022]

[0023] Safety valve opening alarm value L set Calculated according to formula (4);

[0024]

[0025] Among them, p 气0 is the initial gas pressure, L0 is the initial piston position, T0 is the initial gas temperature, T1 is the real-time gas temperature collected by the temperature sensor, and p 油1 The pressure sensor collects oil pressure in real time. upper_limit is the upper limit of oil pressure, p lower_limit is the lower limit of oil pressure, p set Release the oil pressure to the safety valve.

[0026] In some embodiments, the accumulator gas leakage is identified in step five as follows: if |L1-L′1|>A, it indicates that the accumulator nitrogen has leaked, and the equipment health management platform alarms; wherein A is the accumulator nitrogen leakage alarm threshold, which can be measured by testing the accumulator.

[0027] In some embodiments, the oil pressure alarm in step 5 specifically includes: if L1>L upper_limit , indicating that the accumulator has reached the lower limit of oil pressure; if L1 <L upper_limit , indicating that the accumulator has reached the upper limit of oil pressure, the equipment health management platform will alarm; the accumulator alarm includes: if L1 <L set , indicating that the accumulator air pressure is close to the safety valve alarm value, the equipment health management platform will alarm.

[0028] The implementation of the present invention has the following beneficial effects

[0029] The present invention proposes an online monitoring device and method for piston accumulator leakage. The present invention measures the performance parameters of the piston accumulator by using a temperature sensor, a pressure sensor and a phased array ultrasonic probe, and combines the comparative analysis of the theoretical position of the piston in the accumulator and the measured position to compare whether the amount n of gas substance in the accumulator during system operation is reduced relative to the initial amount of pre-charged gas, thereby identifying whether the accumulator is leaking. After exceeding the set value, an alarm prompt is issued, and relevant personnel are notified in time to take corresponding measures to improve the efficiency and quality of operation and maintenance. The present invention has a wide monitoring range, high position detection accuracy, and a detection error of no more than ±3mm. It can realize continuous monitoring of the accumulator piston position, calculate the gas leakage amount and issue a leakage alarm. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of an online monitoring device for leakage of a piston accumulator proposed in an embodiment of the present invention;

[0031] Figure 2A schematic diagram of the principle of detecting the piston position by an ultrasonic phased array probe of an online monitoring device for piston accumulator leakage proposed in an embodiment of the present invention;

[0032] Figure 3 A piston echo schematic diagram of an online monitoring device for piston accumulator leakage proposed in an embodiment of the present invention;

[0033] Figure 4 An online monitoring abnormal alarm flow chart of an online monitoring device for piston accumulator leakage proposed in an embodiment of the present invention;

[0034] Description of the drawings: 1. Reflected echo; 2. Piston echo; 3. Opposite side echo; 4. Accumulator; 5. Piston; 6. Temperature sensor; 7. Phased array ultrasonic probe; 8. Detection host; 9. Pressure sensor; 10. Equipment health management platform; 11. Cylinder wall. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figures 1 to 4 As shown, the present invention proposes an online monitoring device for piston accumulator leakage. The monitoring object of the present invention is a piston accumulator. The method is to identify whether the accumulator leaks based on whether the amount of gas material decreases before and after the accumulator is operated. The specific monitoring quantities are gas temperature, piston position in the accumulator, and oil pressure.

[0037] The device includes a temperature sensor, a phased array ultrasonic probe, a detection host, a pressure sensor and a computer. The temperature sensor and the phased array ultrasonic probe are installed on the outer wall of the cylindrical surface of the accumulator. The temperature sensor and the phased array ultrasonic probe are electrically connected to the detection host respectively. The detection host receives the signals of the temperature sensor and the phased array ultrasonic probe and converts them into digital models. The detection host transmits the digital signals to the computer; the pressure sensor is installed on the accumulator, and the pressure sensor transmits the pressure signal to the computer. The computer is provided with an equipment health management platform. The detection host and the pressure sensor transmit the signals to the computer through data cables, Ethernet or WIFI.

[0038] Among them, the temperature sensor has the function of detecting the gas temperature of the accumulator. Under long-term operation conditions, the gas temperature reaches a steady state, and the cylinder wall temperature is equivalent to the gas temperature. Therefore, the temperature sensor is arranged on the outer wall of the cylindrical surface of the accumulator.

[0039] The ultrasonic phased array probe is used to transmit and receive ultrasonic waves. The principle of detecting the piston position is that the ultrasonic sound beam is incident on the cylinder wall, and part of the energy first forms a reflected echo 1 on the inner wall of the cylinder, and the remaining energy continues to pass through the piston surface to form a piston echo 2. If there is no piston at the current position, it will directly propagate to the inner wall on the opposite side to form an opposite echo 3. Therefore, by monitoring the characteristic wave of piston echo 2, when there is this echo, it proves that the piston is at the current position, and when there is no echo, it means that the piston is not at the current position. According to the chip number that receives the characteristic wave of piston echo 2, the displacement and position of the piston can be determined.

[0040] The detection host has the following functions: ultrasonic excitation control, ultrasonic signal amplification, signal processing and digital-to-analog conversion, and sends the processed digital signal to the equipment health management platform via data cable, Ethernet or WIFI.

[0041] The function of the pressure sensor is to detect the system oil pressure. When the piston moves slowly, the piston's own weight and friction are not considered, and the oil pressure is equivalent to the air pressure. Therefore, the pressure sensor obtains the oil pressure by measuring the gas pressure.

[0042] The computer is equipped with an equipment health management platform, which is used to display the specific values ​​of the above monitoring quantities, and to perform calculations, judgments, and alarms in abnormal situations. The initial state parameters of the accumulator are input into the equipment health management platform, which performs calculations, judgments, and alarms in abnormal situations based on the measurement results.

[0043] The present invention proposes an online monitoring method for piston accumulator leakage, the method comprising:

[0044] Step 1: After the accumulator is pre-charged with gas, the initial state parameters of the accumulator are detected and recorded. The initial state parameters specifically include the initial gas pressure p 气0 (unit: Pa), initial piston position L0 (i.e., the distance between the upper and lower surfaces of the gas chamber, unit: mm), initial gas temperature T0 (K);

[0045] Step 2: Enter the initial status parameters and alarm thresholds in the equipment health management platform; the alarm thresholds can be queried in the maintenance manual, including the oil pressure upper limit p upper_limit , oil pressure lower limit p lower_limit , the safety valve releases the oil pressure p set .

[0046] Step 3: When the accumulator is running, the temperature sensor collects the gas temperature T1 in real time, and the pressure sensor collects the oil pressure p in real time 油1 ,The phased array ultrasonic probe collects the actual position L1 of the piston in the accumulator in real time, and sends the above parameters to the equipment health management platform.

[0047] Step 4: The equipment health management platform receives the gas temperature T1 and oil pressure p 油1 and the actual piston position L1 data, and calculate the theoretical piston position value L′1, the high alarm value L upper_limit , low alarm value L lower_limit And the safety valve opening alarm value L set ; The theoretical value of the piston position L'1 is calculated according to formula (1);

[0048]

[0049] Among them, p 气0 is the initial gas pressure, L0 is the initial piston position, T0 is the initial gas temperature, T1 is the real-time gas temperature collected by the temperature sensor, and p 油1 The pressure sensor collects oil pressure in real time.

[0050] Low alarm value L lower_limit Calculated according to formula (2);

[0051]

[0052] Among them, p upper_limit is the upper limit of oil pressure;

[0053] High alarm value L upper_limit Calculated according to formula (3);

[0054]

[0055] Among them, p lower_limit is the lower limit of oil pressure;

[0056] Safety valve opening alarm value L set Calculated according to formula (4);

[0057]

[0058] Among them, p set Release the oil pressure to the safety valve.

[0059] Step 5: The equipment health management platform compares the actual value L1 of the piston position with the theoretical value L′1 and the high alarm value L upper_limit , low alarm value L lower_limit and the alarm value L set Comparison and judgment are made to identify accumulator gas leakage, oil pressure alarm and accumulator opening alarm.

[0060] The specific identification of accumulator gas leakage is: if |L1-L′1|>A, it means that the accumulator nitrogen has leaked, and the equipment health management platform alarms. Where A is a constant, which is the accumulator nitrogen leakage alarm threshold, and this value can be measured by testing the accumulator.

[0061] The oil pressure alarm includes: if L1>L upper_limit , indicating that the accumulator has reached the lower limit of oil pressure; if L1 <L upper_limit , indicating that the accumulator has reached the upper limit of oil pressure, and the equipment health management platform will sound an alarm.

[0062] The accumulator opening alarm includes: if L1 <L set , indicating that the accumulator air pressure is close to the safety valve alarm value, the equipment health management platform will alarm.

[0063] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. An online monitoring device for leakage of a piston accumulator, characterized in that: The device includes a temperature sensor, a phased array ultrasonic probe, a detection host, a pressure sensor and a computer. The temperature sensor and the phased array ultrasonic probe are installed on the outer wall of the cylindrical surface of the accumulator. The temperature sensor and the phased array ultrasonic probe are electrically connected to the detection host respectively. The detection host receives the signals of the temperature sensor and the phased array ultrasonic probe and converts them into digital models. The detection host transmits the digital signals to the computer. The pressure sensor is arranged on the accumulator, and the pressure sensor transmits the pressure signal to the computer.

2. The piston accumulator leakage online monitoring device according to claim 1, characterized in that: The detection host and the pressure sensor transmit signals to the computer via data lines, Ethernet or WIFI.

3. The on-line monitoring device for piston accumulator leakage according to claim 2, characterized in that: The computer is provided with an equipment health management platform, which performs calculation, judgment, monitoring and alarm by comparing the initial state parameters of the accumulator after pre-charging with gas and the measurement parameters of the detection host and the pressure sensor.

4. A method for online monitoring of piston accumulator leakage according to any one of claims 1 to 3, characterized in that: The method comprises: Step 1: After the accumulator is pre-charged with gas, detecting and recording the initial state parameters of the accumulator; Step 2: Input the initial state parameters and alarm thresholds in the equipment health management platform; Step 3: When the accumulator is running, the temperature sensor collects the gas temperature T1 in real time, and the pressure sensor collects the oil pressure p in real time 油1 , the phased array ultrasonic probe collects the actual position L1 of the piston in the accumulator in real time; Step 4: The equipment health management platform receives the gas temperature T1 and oil pressure p 油1 and the actual piston position L1 data, and calculate the theoretical piston position value L′1, the high alarm value L upper_limit , low alarm value L lower_limit And the safety valve opening alarm value L set ; Step 5: The equipment health management platform compares the actual value L1 of the piston position with the theoretical value L′1 and the high alarm value L upper_limit , low alarm value L lower_limit and the alarm value L set Comparison and judgment are made to identify the accumulator gas leakage, oil pressure alarm and accumulator opening alarm.

5. The method for online monitoring of piston accumulator leakage according to claim 4, characterized in that: The initial state parameters in step 1 include the initial gas pressure p 气0 , initial gas temperature T0 and initial piston position L0.

6. The method for online monitoring of piston accumulator leakage according to claim 3, characterized in that: The alarm threshold in step 2 is queried from the maintenance manual, including the oil pressure upper limit p upper_limit , oil pressure lower limit p lower_limit , the safety valve releases the oil pressure p set .

7. The method for online monitoring of piston accumulator leakage according to claim 3, characterized in that: The theoretical value L′1 of the piston position in step 4 is calculated according to formula (1); Low alarm value L lower_limit Calculated according to formula (2); High alarm value L upper_limit Calculated according to formula (3); Safety valve opening alarm value L set Calculated according to formula (4); Among them, p 气0 is the initial gas pressure, L0 is the initial piston position, T0 is the initial gas temperature, T1 is the real-time gas temperature collected by the temperature sensor, and p 油1 The pressure sensor collects oil pressure in real time. upper_limit is the upper limit of oil pressure, p lower_limit is the lower limit of oil pressure, p set Release the oil pressure to the safety valve.

8. The method for online monitoring of piston accumulator leakage according to claim 3, characterized in that: The accumulator gas leakage is identified in step five as follows: if |L1-L′1|>A, it indicates that the accumulator nitrogen has leaked, and the equipment health management platform alarms; wherein A is the accumulator nitrogen leakage alarm threshold, which can be measured by testing the accumulator.

9. The method for online monitoring of piston accumulator leakage according to claim 3, characterized in that: The oil pressure alarm in step 5 specifically includes: if L1>L upper_limit , indicating that the accumulator has reached the lower limit of oil pressure; if L1 <L upper_limit , indicating that the accumulator reaches the upper limit of oil pressure, the equipment health management platform alarms; the accumulator starts the alarm specifically including: if L1 <L set , indicating that the accumulator air pressure is close to the safety valve alarm value, then the equipment health management platform alarms.

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