Nuclear power secondary circuit steam humidity on-line measuring device and method based on big data

Abstract

The invention relates to the technical field of thermodynamic system monitoring and control, in particular to a nuclear power secondary circuit steam humidity online measuring device and method based on big data. The device comprises a measuring unit and a big data coupling adaptive control system, the measuring unit comprises a sampling steam inlet section, a steam heating section and a steam outlet section which are connected in sequence; an inlet temperature sensor is arranged at an inlet of the steam sampling inlet section; a spiral electric heating sheet for uniformly heating is arranged in the steam heating section and is connected with a power meter, an outlet temperature sensor and a pressure sensor; a mass flow meter and an exhaust valve are connected in the steam outlet section; the big data coupling adaptive control system collects and processes data of all the sensors, the power meter and the mass flow meter, achieves control over the electric heating piece, calculates a humidity measurement result and comprises a big data processing unit and an adaptive PID controller. By introducing the big data technology, the accuracy, the sensitivity and the real-time performance of humidity measurement are improved, so that the influence of humidity change on the stability and the efficiency of the system in the operation of the nuclear power plant is effectively dealt with.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal system monitoring and control, and in particular to a device and method for online measuring steam humidity in a secondary circuit of a nuclear power plant based on big data. Background Art

[0002] Nuclear power is one of the representatives of clean energy, and its operation stability and safety are directly related to the reliability of energy supply. The turbine inlet of nuclear power plants usually uses saturated steam, and the presence of humidity becomes the main cause of blade erosion. This problem not only threatens the safe operation of the turbine, but also reduces the efficiency of the flow section. In the operation of nuclear power plants, accurate measurement of steam humidity is crucial to maintaining the stability of the reactor and improving efficiency. At present, nuclear power plants mainly rely on traditional humidity measurement methods, including thermodynamic method, chemical method, optical method, ultrasonic method, microwave resonant cavity perturbation method, capacitance method, Bragg fiber grating method and surface plasma resonance method. Although these methods can provide reliable measurement results under specific conditions, there are problems such as the measurement accuracy is easily affected by environmental conditions, the response speed is relatively slow, and it is difficult to achieve real-time monitoring of system humidity changes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an online measurement device and method for the steam humidity of a nuclear power secondary circuit based on big data, and to improve the accuracy, sensitivity and real-time performance of humidity measurement by introducing big data technology, so as to effectively cope with the influence of humidity changes during the operation of a nuclear power plant on the stability and efficiency of the system.

[0004] The present invention provides a nuclear power secondary circuit steam humidity online measurement device based on big data, comprising: a measurement unit and a big data coupled adaptive control system;

[0005] The measuring unit comprises a sampling steam inlet section, a steam heating section and a steam outlet section connected in sequence;

[0006] An inlet temperature sensor is provided at the inlet of the steam sampling inlet section;

[0007] The steam heating section is equipped with a spiral electric heating plate for uniform heating, which is connected to a power meter, an outlet temperature sensor and a pressure sensor;

[0008] A mass flow meter and an exhaust valve are connected to the steam outlet section;

[0009] The big data coupled adaptive control system collects and processes data from various sensors, power meters and mass flow meters, realizes control of the electric heating plate and calculates humidity measurement results, and includes a big data processing unit and an adaptive PID controller.

[0010] In a specific embodiment of the present invention, the measuring unit adopts a heat-insulating pipe.

[0011] In a specific embodiment of the present invention, the steam heating section is coated with a layer of silica aerogel felt.

[0012] In a specific embodiment of the present invention, the inner diameter of the steam heating section is 2-3 times the inner diameter of the sampling steam inlet section.

[0013] In a specific embodiment of the present invention, the outlet temperature sensor and pressure sensor of the steam heating section are arranged on the pipe wall near the tail of the spiral electric heating plate and are located at two end points of the same cross-sectional circular diameter.

[0014] In a specific embodiment of the present invention, the big data processing unit stores historical operating data of wet steam, trains steam humidity and temperature distribution models, establishes steam humidity and temperature distribution models in different equipment under different loads of the unit, and expands and updates the database and screens out bad points as the number of uses increases; the big data processing unit has the function of retrieving real-time data online, and obtains real-time operating load data of the current power system through corresponding interfaces or communication protocols.

[0015] In a specific embodiment of the present invention, the electric heating plate is heated by a heating power supply, and the adaptive PID controller determines the predicted humidity and heating power range in combination with the operating load data, controls and adjusts the voltage of the heating power supply to perform controlled heating, collects the sensor data after heating, and calculates the humidity.

[0016] In a specific embodiment of the present invention, the big data coupled adaptive control system also includes a fault warning and diagnosis module, a data display module, and an intelligent report generation module.

[0017] The present invention also provides a method for online measurement of steam humidity in a nuclear power secondary circuit based on big data, comprising the following steps:

[0018] Step 1: The sampled wet saturated steam enters the inlet section of the device, and the inlet temperature T1 is measured at the inlet;

[0019] Step 2: The big data coupled adaptive control system retrieves the real-time operating load data for analysis, locks the possible working equipment of the steam to be tested, calculates and predicts the humidity and heating power range based on the historical operating data of the working equipment, and obtains the average power and the maximum power within the range to adjust the power supply voltage for controlled heating; by analyzing the temperature and pressure of the steam after heating, it is determined whether the steam has reached the overheating state under the two voltage regulation heating conditions;

[0020] If both steam types are not overheated, the predicted humidity and heating power range are recalculated based on the historical operating data of the working equipment, the heating is adjusted and the comparison results are calculated;

[0021] If both steams are superheated, calculate whether the humidity results under the two voltages are consistent;

[0022] If they are consistent, the humidity result is output and the database is updated;

[0023] If there is inconsistency, within the calculation upper limit, other possible working equipment will be re-locked, historical operation data will be retrieved to re-predict data and adjust the heating power for calculation and comparison; if the calculation upper limit is reached, the default superheat setting of 10°C will be used for heating, and the controller will determine whether the steam is overheated based on the data after heating and execute heating or calculate the humidity result command.

[0024] In a specific embodiment of the present invention, in step S2, the humidity is calculated as follows:

[0025] 1) According to the inlet temperature T1 measured at the inlet, the saturated gas phase enthalpy h″ and saturated liquid phase enthalpy h′, as well as the mass flow rate G, are obtained to calculate the saturated steam inlet enthalpy value:

[0026]

[0027] Where: is the inlet enthalpy of saturated steam, kW; y is the required humidity; h′ is the saturated liquid phase enthalpy; h″ is the saturated gas phase enthalpy; G is the mass flow rate of steam;

[0028] 2) According to the temperature T2 and pressure P of superheated steam, the specific enthalpy h2 of superheated steam is obtained, and the enthalpy value of superheated steam is calculated:

[0029]

[0030] Where: is the enthalpy of superheated steam; h2 is the specific enthalpy of superheated steam; G is the mass flow rate of steam;

[0031] 3) Since the heat absorption process of steam in the heating section satisfies the following energy conservation law:

[0032]

[0033] Where: is the heat absorption of steam, kW; It is the heat lost by wet steam in this process; is the change in wet steam enthalpy; MgΔh is the potential energy of wet steam; The work done by wet steam before and after heating; is the kinetic energy of wet steam;

[0034] 4) Since the wet steam heat absorption process in the device can be regarded as zero heat loss, zero external work, and zero potential energy change, we have:

[0035]

[0036] The energy conservation equation can be simplified to:

[0037] Right now

[0038] 5) Substituting the above equations into the formula, we get:

[0039] h2G=[yh'+(1-y)h"]G+UI

[0040] Calculate the humidity y of wet steam:

[0041]

[0042] Wherein: h2 is the specific enthalpy of superheated steam, kJ / kg; G is the mass flow rate of steam; y is the required humidity; h′ is the saturated liquid phase enthalpy; h″ is the saturated gas phase enthalpy; UI is the heating power. Compared with the prior art, the online measurement device and method for steam humidity in the secondary circuit of nuclear power plant based on big data of the present invention has the following beneficial effects:

[0043] (1) Improve measurement accuracy by integrating big data technology and using large amounts of historical data and operational data for pattern recognition and prediction;

[0044] (2) The control strategy of steam humidity measurement can be dynamically adjusted based on the continuously updated big data information, so that the measurement device can automatically optimize operation under various working conditions and improve measurement accuracy;

[0045] (3) Real-time online monitoring of the steam humidity in the secondary circuit of a nuclear power plant ensures that operators are aware of changes in steam quality in a timely manner, which is crucial for maintaining turbine operating efficiency and avoiding corrosion problems caused by excessive steam humidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram showing an online measurement device for steam humidity in a nuclear power secondary circuit based on big data according to the present invention;

[0047] Figure 2 A schematic diagram showing a control flow of a big data coupled adaptive control system of an online measurement device for steam humidity in a nuclear power secondary circuit based on big data according to the present invention;

[0048] In the figure, 1. steam inlet section; 2. steam heating section; 3. thermal insulation pipe; 4. silica aerogel felt pad; 5. spiral electric heating plate; 6. waterproof insulating bolt; 7. outlet temperature sensor; 8. steam outlet section; 9. mass flow meter; 10. exhaust valve; 11. inlet temperature sensor; 12. heating power supply; 13. power meter; 14. big data coupled adaptive control system; 15. adaptive PID controller; 16. big data processing unit; 17. pressure sensor. DETAILED DESCRIPTION

[0049] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0050] The embodiment of the present invention discloses a nuclear power secondary circuit steam humidity online measurement device based on big data, such as Figure 1 As shown, it includes: a measurement unit and a big data coupled adaptive control system 14;

[0051] The measuring unit comprises a sampling steam inlet section 1, a steam heating section 2 and a steam outlet section 8 connected in sequence;

[0052] The measuring unit adopts heat-insulating pipe 3;

[0053] The steam heating section 2 is coated with a layer of silica aerogel felt pad 4;

[0054] The inner diameter of the steam heating section 2 is 2-3 times the inner diameter of the sampling steam inlet section 1;

[0055] An inlet temperature sensor 11 is provided at the inlet of the steam sampling inlet section 1;

[0056] A spiral electric heating plate 5 for uniform heating is arranged in the steam heating section 2, which is connected to a power meter 13, an outlet temperature sensor 7 and a pressure sensor 17;

[0057] Both ends of the spiral electric heating plate 5 are connected to a heating power source 12 and fixed with waterproof insulating bolts 6 on the pipe wall.

[0058] The spiral electric heating plate 5 can provide an efficient heating effect. The spiral structure can enhance the heat exchange disturbance, increase the heat exchange area, improve the heating efficiency, and reduce the heating loss, thereby changing the heat absorption of steam by adjusting the electric heating power and more effectively measuring the steam humidity.

[0059] The outlet temperature sensor 7 and the pressure sensor 17 of the steam heating section 2 are arranged on the pipe wall near the tail of the spiral electric heating plate 5 and are located at the two end points of the same cross-sectional circular diameter.

[0060] The steam outlet section 8 is connected with a mass flow meter 9 and an exhaust valve 10;

[0061] The big data coupled adaptive control system 14 collects and processes data from each sensor, power meter 13 and mass flow meter 9 to control the electric heating plate 5 and calculate the humidity measurement result. It includes a big data processing unit 16 and an adaptive PID controller 15.

[0062] The big data processing unit 16 includes a database, a data processing module, a data acquisition module, and a steam humidity and temperature distribution model;

[0063] The database stores historical wet steam operation data, trains the steam humidity and temperature distribution model, establishes the steam humidity and temperature distribution model in different equipment under different loads, and expands and updates the database and removes bad points as the number of uses increases; the big data processing unit 16 has the function of online access to real-time data, and obtains the real-time operation load data of the current power system through the corresponding interface or communication protocol. The function of the data processing module is to read the implementation data and perform data processing to obtain data that can be used for data training / calculation.

[0064] The electric heating plate is heated by a heating power supply. The adaptive PID controller determines the predicted humidity and heating power range in combination with the operating load data, controls and adjusts the voltage of the heating power supply to perform controlled heating, collects the data of each sensor after heating, and calculates the humidity.

[0065] The big data coupled adaptive control system 14 also includes a fault warning and diagnosis module, a data display module, and an intelligent report generation module.

[0066] The fault warning and diagnosis module, using big data analysis, can detect the trend of abnormal changes in steam humidity in advance and implement fault warning, which is conducive to shortening fault response time, reducing unplanned downtime, and extending equipment service life.

[0067] The data display module and the intelligent report generation module provide maintenance personnel with clear decision-making basis through data visualization and intelligent reports, simplify the operation and maintenance process, reduce operation and maintenance costs, and improve the overall management level.

[0068] The specific working process of the big data coupled adaptive control system 14 is as follows: the inlet temperature sensor 11 transmits the inlet temperature of the wet steam to be measured to the adaptive PID controller 15, the adaptive PID controller 15 determines the predicted humidity and heating power range in combination with the real-time operating load data provided by the big data processing unit 16, and adjusts the voltage of the heating power supply 12 according to the average power and the maximum power within the range to perform controlled heating; collects the data of each sensor after heating, compares whether the actual humidity results calculated under the two voltages are consistent, and corrects the heating power supply 12 until the adaptive PID controller 15 calculates an accurate result.

[0069] In the big data coupled adaptive control system 14, the humidity of the working steam in different devices has a certain range of values. When the load changes, the working steam temperature of each device will change accordingly, while the humidity range is relatively stable. Therefore, the big data processing unit 16 first determines the working equipment of the steam to be tested in combination with the initial temperature based on the established steam temperature and humidity distribution model, thereby determining the humidity change range for reasonable prediction; if the calculation result does not meet the output condition all the time and has exceeded the system calculation upper limit, the heating power supply 12 heats according to the default superheat setting of 10°C for the inlet temperature of the steam to be tested, and the adaptive PID controller 15 determines whether the steam is overheated based on the heated data and executes the heating or humidity calculation result command.

[0070] The present invention establishes a humidity and temperature distribution model of steam under different loads, so that the big data coupled adaptive control system can accurately identify the working equipment of the steam to be tested, thereby more accurately predicting the humidity variation range. In addition, the result calculated by the controller each time will be compared with the calculation result under the maximum heating power, so as to realize real-time online monitoring and verification of humidity and improve the efficiency and accuracy of humidity measurement.

[0071] The big data processing unit adopted in the present invention has the function of retrieving real-time data online. By acquiring the real-time operating load data of the current power system, the predicted range of humidity can be determined more accurately, the real-time regulation of heating power can be achieved, and the database can be expanded and updated as the number of uses increases, so that the system can better adapt to different working conditions and load changes.

[0072] The embodiment of the present invention also discloses a method for online measurement of steam humidity in a nuclear power secondary circuit based on big data, such as Figure 2 As shown, the following steps are included:

[0073] Step 1: The sampled wet saturated steam enters the inlet section of the device, and the inlet temperature T1 is measured at the inlet;

[0074] Step 2: The big data coupled adaptive control system retrieves the real-time operating load data for analysis, locks the possible working equipment of the steam to be tested, calculates and predicts the humidity and heating power range based on the historical operating data of the working equipment, and obtains the average power and the maximum power within the range to adjust the power supply voltage for controlled heating; by analyzing the temperature and pressure of the steam after heating, it is determined whether the steam has reached the overheating state under the two voltage regulation heating conditions;

[0075] If both steam types are not overheated, the predicted humidity and heating power range are recalculated based on the historical operating data of the working equipment, the heating is adjusted and the comparison results are calculated;

[0076] If both steams are superheated, calculate whether the humidity results under the two voltages are consistent;

[0077] If they are consistent, the humidity result is output and the database is updated;

[0078] If there is inconsistency, within the calculation upper limit, other possible working equipment will be re-locked, historical operation data will be retrieved to re-predict data and adjust the heating power for calculation and comparison; if the calculation upper limit is reached, the default superheat setting of 10°C will be used for heating, and the controller will determine whether the steam is overheated based on the data after heating and execute heating or calculate the humidity result command.

[0079] The calculation method of humidity is:

[0080] 1) According to the inlet temperature T1 measured at the inlet, the saturated gas phase enthalpy h″ and saturated liquid phase enthalpy h′, as well as the mass flow rate G, are obtained to calculate the saturated steam inlet enthalpy value:

[0081]

[0082] Where: is the inlet enthalpy of saturated steam, kW; y is the required humidity; h′ is the saturated liquid phase enthalpy, kJ / kg; h″ is the saturated gas phase enthalpy, kJ / kg; G is the mass flow rate of steam, kg / s;

[0083] 2) According to the temperature T2 and pressure P of superheated steam, the specific enthalpy h2 of superheated steam is obtained, and the enthalpy value of superheated steam is calculated:

[0084]

[0085] Where: is the enthalpy of superheated steam, kW; h2 is the specific enthalpy of superheated steam, kJ / kg; G is the mass flow rate of steam, kg / s;

[0086] 3) Since the heat absorption process of steam in the heating section satisfies the following energy conservation law:

[0087]

[0088] Where: is the heat absorption of steam, kW; is the heat dissipated by wet steam in this process, kW; is the change in wet steam enthalpy, kW; MgΔh is the potential energy of wet steam, kW; The work done by wet steam before and after heating, kW; is the kinetic energy of wet steam, kW;

[0089] 4) Since the wet steam heat absorption process in the device can be regarded as zero heat loss, zero external work, and zero potential energy change, we have:

[0090]

[0091] The energy conservation equation can be simplified to:

[0092] Right now

[0093] 5) Substituting the above equations together, we get:

[0094] h2G=[yh'+(1-y)h"]G+UI

[0095] Calculate the humidity y of wet steam:

[0096]

[0097] Where h2 is the specific enthalpy of superheated steam, kJ / kg; G is the mass flow rate of steam, kg / s; y is the required humidity; h′ is the saturated liquid phase enthalpy, kJ / kg; h″ is the saturated gas phase enthalpy, kJ / kg; UI is the heating power, kW.

[0098] The present invention has significant practical value. It can not only improve the safety and reliability of nuclear power plant operation, but also help to achieve more refined operation management, which is in line with the development trend of intelligent management of modern nuclear power plants.

[0099] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0100] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A nuclear power secondary circuit steam humidity online measurement device based on big data, characterized in that: include: Measurement unit and big data coupled adaptive control system (14); The measuring unit comprises a sampling steam inlet section (1), a steam heating section (2) and a steam outlet section (8) which are connected in sequence; An inlet temperature sensor is provided at the inlet of the steam sampling inlet section (1); A spiral electric heating plate (5) for uniform heating is arranged in the steam heating section (2), and is connected to a power meter, an outlet temperature sensor and a pressure sensor; The steam outlet section (8) is connected to a mass flow meter (9) and an exhaust valve (10); The big data coupled adaptive control system (14) collects and processes data from various sensors, power meters and mass flow meters, realizes control of the electric heating plate and calculates humidity measurement results, and includes a big data processing unit (16) and an adaptive PID controller (15).

2. The online measurement device for steam humidity in the secondary circuit of nuclear power plant based on big data according to claim 1 is characterized in that: The measuring unit adopts heat-insulating pipe material.

3. The online measurement device for steam humidity in the secondary circuit of nuclear power plant based on big data according to claim 2 is characterized in that: The steam heating section is coated with a layer of silicon dioxide aerogel felt pad.

4. The online measurement device for steam humidity in the secondary circuit of nuclear power plant based on big data according to claim 1 is characterized in that: The inner diameter of the steam heating section (2) is 2-3 times the inner diameter of the sampling steam inlet section (1).

5. The online measurement device for nuclear power secondary circuit steam humidity based on big data according to claim 1 is characterized in that: The outlet temperature sensor (7) and the pressure sensor (17) of the steam heating section (2) are arranged on the pipe wall near the tail of the spiral electric heating plate (5) and are located at the two end points of the same cross-sectional circular diameter.

6. The online measurement device for nuclear power secondary circuit steam humidity based on big data according to claim 1 is characterized in that: The big data processing unit (16) stores historical wet steam operation data, trains steam humidity and temperature distribution models, establishes steam humidity and temperature distribution models in different equipment under different loads of the unit, and expands and updates the database and screens out bad points as the number of uses increases; the big data processing unit (16) has the function of online retrieval of real-time data, and obtains real-time operation load data of the current power system through a corresponding interface or communication protocol.

7. The online measurement device for steam humidity in the secondary circuit of nuclear power plant based on big data according to claim 6 is characterized in that: The electric heating plate is heated by a heating power supply. The adaptive PID controller determines the predicted humidity and heating power range in combination with the operating load data, controls and adjusts the voltage of the heating power supply to perform controlled heating, collects the data of each sensor after heating, and calculates the humidity.

8. The online measurement device for steam humidity in the secondary circuit of nuclear power plant based on big data according to claim 1 is characterized in that: The big data coupled adaptive control system also includes a fault warning and diagnosis module, a data display module, and an intelligent report generation module.

9. A method for online measurement of steam humidity in a nuclear power secondary circuit based on big data, characterized in that: The following steps are involved: Step 1: The sampled wet saturated steam enters the inlet section of the device, and the inlet temperature T1 is measured at the inlet; Step 2: The big data coupled adaptive control system retrieves the real-time operating load data for analysis, locks the possible working equipment of the steam to be tested, calculates and predicts the humidity and heating power range based on the historical operating data of the working equipment, and obtains the average power and the maximum power within the range to adjust the power supply voltage for controlled heating; by analyzing the temperature and pressure of the steam after heating, it is determined whether the steam has reached the overheating state under the two voltage regulation heating conditions; If both steam types are not overheated, the predicted humidity and heating power range are recalculated based on the historical operating data of the working equipment, the heating is adjusted and the comparison results are calculated; If both steams are superheated, calculate whether the humidity results under the two voltages are consistent; If they are consistent, the humidity result is output and the database is updated; If there is inconsistency, within the calculation upper limit, other possible working equipment will be re-locked, historical operation data will be retrieved to re-predict data and adjust the heating power for calculation and comparison; if the calculation upper limit is reached, the default superheat setting of 10°C will be used for heating, and the controller will determine whether the steam is overheated based on the data after heating and execute heating or calculate the humidity result command.

10. The method for online measurement of steam humidity in a nuclear power secondary circuit based on big data according to claim 9 is characterized in that: In step S2, the humidity is calculated as follows: 1) According to the inlet temperature T1 measured at the inlet, the saturated gas phase enthalpy h″ and saturated liquid phase enthalpy h′, as well as the mass flow rate G, are obtained to calculate the saturated steam inlet enthalpy value: Where: is the inlet enthalpy of saturated steam, kW; y is the required humidity; h′ is the saturated liquid phase enthalpy; h″ is the saturated gas phase enthalpy; G is the mass flow rate of steam; 2) According to the temperature T2 and pressure P of superheated steam, the specific enthalpy h2 of superheated steam is obtained, and the enthalpy value of superheated steam is calculated: Where: is the enthalpy of superheated steam; h2 is the specific enthalpy of superheated steam; G is the mass flow rate of steam; 3) Since the heat absorption process of steam in the heating section satisfies the following energy conservation law: Where: is the heat absorption of steam, kW; It is the heat lost by wet steam in this process; is the change in wet steam enthalpy; MgΔh is the potential energy of wet steam; The work done by wet steam before and after heating; is the kinetic energy of wet steam; 4) Since the wet steam heat absorption process in the device can be regarded as zero heat loss, zero external work, and zero potential energy change, we have: The energy conservation equation can be simplified to: Right now 5) Substituting the above equations together, we get: h2G=[yh'+(1-y)h"]G+UI Calculate the humidity y of wet steam: Where: h2 is the specific enthalpy of superheated steam, kJ / kg; G is the mass flow rate of steam; y is the required humidity; h′ is the saturated liquid phase enthalpy; h″ is the saturated gas phase enthalpy; UI is the heating power.

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