Device for preventing power plant steam extraction check valve analog quantity feedback overtemperature aging

Abstract

The invention provides a device for preventing power plant steam extraction check valve analog quantity feedback overtemperature aging, and relates to the technical field of valves.The device comprises a valve clack fixing base, a valve clack rotating shaft is rotationally arranged on the valve clack fixing base, and a first extending rotating shaft is connected to the valve clack rotating shaft through a fastener; a second extension rotating shaft is rotationally arranged on one side of the rotating sensor, the first extension rotating shaft is fixedly connected with the second extension rotating shaft through a fastener, a heat insulation fixing support is fixedly arranged between the valve clack fixing base and the rotating sensor, and the heat insulation fixing support reduces the operating environment temperature of the rotating sensor; the failure rate of the analog quantity rotation sensor can be reduced, analog quantity feedback of the valve can measure the real-time opening degree of the valve through the rotation sensor, analog quantity signal changes of the opening degree are fed back to a control system in real time, accurate flow control is achieved or specific process conditions are kept, and normal and safe operation of a thermal power generating unit is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of valve technology, and in particular to a device for preventing over-temperature aging of analog feedback of a steam extraction check valve in a power plant. Background Art

[0002] Coal-fired thermal power unit steam turbine extraction check valve is widely used in the steam turbine extraction system of thermal power plants, as well as other occasions where medium backflow needs to be prevented, such as high-pressure cylinder exhaust pipes, extraction pipes, etc. Its core function is to protect important equipment such as steam turbines, heaters and pipelines from possible damage caused by medium backflow. When medium such as steam or water attempts to backflow under certain conditions, the extraction check valve will quickly close, effectively blocking the backflow path and ensuring the safe operation of the system.

[0003] At present, the analog feedback of the extraction check valve adopts TXP rotary sensor to measure the rotation angle of the valve disc when the valve is open or closed, and feeds back the actual opening of the check valve. Since the analog feedback of the extraction check valve of the 1000MW thermal power unit adopts TXP rotary sensor for measurement, the rotation axis of the rotation sensor and the valve disc must be installed on the same center line. The existing rotation sensor must be installed close to the rotation axis of the valve disc, resulting in excessively high ambient temperature during the operation of the rotation sensor, high failure rate of the rotation sensor and shortened service life.

[0004] Therefore, in view of the above situation, it is urgent to develop a device to prevent the over-temperature aging of the analog feedback of the steam extraction check valve of the power plant, so as to overcome the shortcomings in current practical applications. Summary of the invention

[0005] The invention provides a device for preventing over-temperature aging of analog feedback of a steam extraction check valve of a power plant, so as to solve the defects in the prior art.

[0006] The present invention provides a device for preventing over-temperature and aging of analog feedback of a steam extraction check valve in a power plant, comprising: a valve flap fixing base, a valve flap rotating shaft is rotatably arranged on the valve flap fixing base, a first extended rotating shaft is connected to the valve flap rotating shaft through a locking device, a second extended rotating shaft is rotatably arranged on one side of a rotation sensor, the first extended rotating shaft is fixedly connected to the second extended rotating shaft through a locking device, and a heat-insulating fixed bracket is fixedly arranged between the valve flap fixing base and the rotation sensor.

[0007] Preferably, it also includes:

[0008] A data acquisition module is provided, wherein a monitoring sensor is installed in the steam extraction check valve to collect parameters of the steam extraction check valve in real time;

[0009] Demand analysis module, used to analyze demand parameters input by users;

[0010] The parameter adjustment module is used to continuously detect the parameters of the extraction steam check valve and adjust the opening of the extraction steam check valve according to demand;

[0011] Early warning module 1: when the parameters of the extraction steam check valve are greater than or equal to the required parameters input by the user, an early warning is issued.

[0012] Preferably, the monitoring sensors include: a rotation sensor, a temperature sensor, a pressure sensor, and a flow sensor.

[0013] Preferably, the demand analysis module includes:

[0014] Feature acquisition unit: extracts several initial features from the demand parameters input by the user, and analyzes the initial features to obtain several key features;

[0015] Model building unit: determining the demand forecasting model in a preset feature type-model database based on the feature type of the key feature, and then establishing the demand forecasting model;

[0016] Demand acquisition unit: inputs the user demand parameters collected in real time into the demand prediction model to obtain several user demands.

[0017] Preferably, the demand parameters input by the user include: steam flow demand in the extraction check valve, pressure demand in the extraction check valve, temperature demand of the extraction check valve, and operating time characteristic demand of the extraction check valve.

[0018] Preferably, the parameter adjustment module includes:

[0019] Coefficient determination unit 1: determining the gas supply change coefficient for each time period based on user demand;

[0020] Coefficient determination unit 2: determining the temperature variation coefficient based on the air supply variation coefficient;

[0021] Classification unit: divides users into several demand levels based on their steam flow requirements and preset classification methods;

[0022] Parameter acquisition unit: obtains the opening and closing range and sensitivity of each type of steam extraction check valve based on the preset operation manual;

[0023] Parameter setting unit: setting the opening and closing range and sensitivity of the corresponding check valve based on the demand level of each user and the opening and closing range and sensitivity of each type of steam extraction check valve;

[0024] Early warning module 2: when the temperature change coefficient is greater than the preset temperature change coefficient, an early warning is issued;

[0025] Regulation control unit: Based on the steam supply coefficient of each time period, the temperature variation coefficient, the demand level of each user, the opening and closing range and sensitivity of each extraction check valve, the regulation strategy is determined to adjust the opening of the extraction check valve.

[0026] Preferably, the coefficient determination unit 1 includes:

[0027] Based on the user's steam flow demand, user's steam pressure demand and user's time characteristic demand, determine the air supply variation coefficient in the extraction check valve in each time period:

[0028]

[0029] Where, j is the air supply variation coefficient in the extraction check valve, C m is the steam flow coefficient at the minimum relative opening, C d is the steam flow coefficient at the maximum relative opening, γ is the steam expansion coefficient, P1 is the pressure in the extraction check valve before air supply, P2 is the pressure in the extraction check valve after air supply, W1 is the preset maximum flow demand, W2 is the preset minimum flow demand, μ is the compression coefficient of the steam passing through the extraction check valve, ε is the resistance coefficient of the extraction check valve, and ρ is the density of the steam in the extraction check valve.

[0030] Preferably, the coefficient determination unit 2 includes:

[0031]

[0032] Wherein, N is the temperature variation coefficient of the extraction check valve, b is the turbulent flux, s is the movement distance of the steam in the extraction check valve, δ is the viscosity coefficient, and β is the diffusion coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic diagram of the overall structure provided by an embodiment of the present invention.

[0035] Reference numerals:

[0036] 1. Valve disc fixing base; 2. Valve disc rotating shaft; 3. First extended rotating shaft; 4. Locking device; 5. Second extended rotating shaft; 6. Rotation sensor; 7. Heat insulation fixing bracket. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not 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.

[0038] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] The present invention provides the following embodiments

[0040] Example 1

[0041] The embodiment of the present invention provides a device for preventing over-temperature aging of analog feedback of steam extraction check valve in a power plant, such as Figure 1 As shown, it includes: a valve flap fixing base 1, a valve flap rotating shaft 2 is rotatably arranged on the valve flap fixing base 1, a first extended rotating shaft 3 is connected to the valve flap rotating shaft 2 through a locking device 4, a second extended rotating shaft 5 is rotatably arranged on one side of a rotation sensor 6, the first extended rotating shaft 3 is fixedly connected to the second extended rotating shaft 5 through the locking device 4, and a heat insulating fixed bracket 7 is fixedly arranged between the valve flap fixing base 1 and the rotation sensor 6.

[0042] The working principle and beneficial effects of the above technical solution are as follows: the valve flap fixing base 1 rotatably supports the valve flap rotating shaft 2, the latch 4 synchronously rotates and connects the valve flap rotating shaft 2 and the first extended rotating shaft 3, the latch 4 also synchronously rotates and connects the first extended rotating shaft 3 and the second extended rotating shaft 5, the heat-insulating fixed bracket 7 fixes and connects the valve flap fixing base 1 and the rotation sensor 6, thereby increasing the stability of the valve flap fixing base 1 and the rotation sensor 6 without affecting the synchronous rotation of the valve flap rotating shaft 2, the first extended rotating shaft 3 and the second extended rotating shaft 5, and the heat-insulating fixed bracket 7 also reduces heat conduction and reduces rotation The operating environment temperature of the sensor 6 can reduce the failure rate of the analog rotation sensor 6 and increase its service life, so that the analog feedback of the valve can measure the real-time opening of the valve through the rotation sensor 6, and feed back the change of the analog signal of the opening to the control system in real time. The control system adjusts the opening of the valve or other control parameters according to the feedback signal to achieve precise flow control or maintain specific process conditions. At the same time, the operation monitoring personnel can monitor the operating status of the steam extraction check valve. Under abnormal operating conditions, the operating personnel can respond to changes in system parameters in a timely manner and perform corresponding operations to ensure the normal and safe operation of the thermal power unit.

[0043] Example 2

[0044] On the basis of Example 1, it also includes:

[0045] A data acquisition module is provided, wherein a monitoring sensor is installed in the steam extraction check valve to collect parameters of the steam extraction check valve in real time;

[0046] The demand analysis module is used to analyze the demand parameters input by the user. The parameter adjustment module continuously detects the parameters of the extraction steam check valve and adjusts the opening of the extraction steam check valve according to the demand.

[0047] Early warning module 1: when the parameters of the extraction steam check valve are greater than or equal to the required parameters input by the user, an early warning is issued.

[0048] In this embodiment, the parameters of the steam extraction check valve include data such as the real-time rotation amount, temperature, pressure intensity, flow rate, etc. of the steam extraction check valve.

[0049] In this embodiment, the opening degree of the extraction steam check valve is regulated by adjusting the opening degree of the extraction steam check valve according to the real-time analysis result.

[0050] The working principle and beneficial effects of the above technical scheme are as follows: the data acquisition module includes collecting the temperature, pressure and flow rate in the steam extraction check valve, and is used to collect the real-time parameters of the steam extraction check valve in real time; the demand analysis module is used to analyze the demand parameters input by the user; the parameter adjustment module refers to continuous detection based on the parameters of the steam extraction check valve, and adjusting the opening of the steam extraction check valve according to the demand; the early warning module 1, when the parameters of the steam extraction check valve are greater than or equal to the demand parameters input by the user, issues an early warning, obtains the real-time parameters of the steam extraction check valve through the data acquisition module, and adjusts the opening of the steam extraction check valve through the user's demand analysis to adjust the heating efficiency in the steam extraction check valve; and monitors and warns by comparing the continuous monitoring with the demand input by the user, thereby enhancing the flexibility and safety of the steam extraction check valve and ensuring the normal and safe operation of the thermal power unit.

[0051] Example 3

[0052] Based on Example 2, the monitoring sensors include: a rotation sensor 6, a temperature sensor, a pressure sensor, and a flow sensor.

[0053] In this embodiment, the rotation sensor 6 is used to detect the real-time opening amount of the extraction steam check valve.

[0054] In this embodiment, the pressure sensor is used to detect the fluid pressure in the steam extraction check valve. By real-time monitoring of pressure changes, the safety of the heating system can be ensured to prevent failures caused by overpressure or underpressure. At the same time, the pressure data can help analyze the flow state of the pipeline and optimize the flow efficiency of the heat medium.

[0055] In this embodiment, the temperature sensor is used to detect the temperature of the steam inlet and outlet in the extraction check valve. These data are helpful to evaluate the heating effect and thermal efficiency of the system. By comparing the inlet and outlet steam temperatures, it is determined whether the user's heating needs are met and adjustments are made when necessary.

[0056] In this embodiment, the flow sensor is used to measure the steam flow through the extraction check valve. The flow data is a key parameter for understanding the actual heat usage at the user end, which helps to adjust the extraction check valve in time to meet the needs of the user and optimize the system operation. By monitoring the flow, the efficient distribution of heat energy can be ensured and energy waste can be reduced.

[0057] The working principle and beneficial effects of the above technical solution are: the rotation sensor 6 detects the opening of the steam extraction check valve, the temperature sensor detects the temperature of the steam extraction check valve, the pressure sensor detects the pressure of the steam extraction check valve, and the flow sensor detects the flow in the steam extraction check valve, thereby providing the required parameters for each module.

[0058] Example 4

[0059] Based on Example 3, the demand analysis module includes:

[0060] Feature acquisition unit: extracts several initial features from the demand parameters input by the user, and analyzes the initial features to obtain several key features;

[0061] Model building unit: determining the demand forecasting model in a preset feature type-model database based on the feature type of the key feature, and then establishing the demand forecasting model;

[0062] Demand acquisition unit: inputs the user demand parameters collected in real time into the demand prediction model to obtain several user demands.

[0063] In this embodiment, the initial features are raw data extracted from the user-side parameters, including: user heat consumption: such as the total heat consumption of the user in a certain period of time, ambient temperature: the outside temperature affects the user's heating demand, time period information: such as the user's heat consumption in different time periods of the day (morning, afternoon, evening);

[0064] In this embodiment, key features are features extracted from initial features and analyzed to be considered to have a significant impact on user demand. For example: peak heat consumption: the maximum heat demand of users during high demand periods, temperature difference: a large difference in inlet and outlet water temperatures may indicate that the user's heating demand is changing, and historical heat usage patterns: the user's heat usage behavior patterns in the past few days or weeks, which helps predict future demand.

[0065] In this embodiment, the preset feature type-model database is a system including various feature types and their corresponding models. For example, temperature feature: the corresponding model may be a linear model based on regression analysis, flow feature: there may be a prediction model based on time series analysis, comprehensive feature: a complex model may be established using a machine learning algorithm (such as random forest or neural network).

[0066] In this embodiment, the demand forecasting model is a model established based on key features and historical data, and is used to predict the user's future heat demand. For example: linear regression model: using historical heat usage data and ambient temperature to establish a linear relationship between user demand and these factors, time series model: analyzing the seasonal and cyclical fluctuations of the user's historical heat usage data to predict future demand, machine learning model: using complex algorithms such as random forests and support vector machines to make predictions based on multi-dimensional features to improve accuracy.

[0067] The working principle and beneficial effects of the above technical solution are as follows: the feature acquisition unit extracts several initial features from the demand parameters input by the user, and analyzes the initial features to obtain several key features; the model construction unit determines the demand prediction model in the preset feature type-model database based on the feature type of the key features, and then establishes the demand prediction model; the demand acquisition unit inputs the user demand parameters collected in real time into the demand prediction model, and then obtains several user demands.

[0068] Example 5

[0069] Based on Example 4, the demand parameters input by the user include: steam flow demand in the extraction check valve, pressure demand in the extraction check valve, temperature demand of the extraction check valve, and operating time characteristic demand of the extraction check valve.

[0070] The working principle and beneficial effects of the above technical solution are as follows: the demand parameters input by the user include: the steam flow demand in the extraction check valve, the pressure demand in the extraction check valve, the temperature demand of the extraction check valve, and the operating time characteristic demand of the extraction check valve.

[0071] Example 6

[0072] Based on Example 5, the parameter adjustment module includes:

[0073] Coefficient determination unit 1: determining the gas supply change coefficient for each time period based on user demand;

[0074] Coefficient determination unit 2: determining the temperature variation coefficient based on the air supply variation coefficient;

[0075] Classification unit: divides users into several demand levels based on their steam flow requirements and preset classification methods;

[0076] Parameter acquisition unit: obtains the opening and closing range and sensitivity of each type of steam extraction check valve based on the preset operation manual;

[0077] Parameter setting unit: setting the opening and closing range and sensitivity of the corresponding steam extraction check valve based on the demand level of each user and the opening and closing range and sensitivity of each type of steam extraction check valve;

[0078] Early warning module 2: when the temperature change coefficient is greater than the preset temperature change coefficient, an early warning is issued;

[0079] Regulation control unit: Based on the steam supply coefficient of each time period, the temperature variation coefficient, the demand level of each user, the opening and closing range and sensitivity of each extraction check valve, the regulation strategy is determined to adjust the opening of the extraction check valve.

[0080] In this embodiment, the preset classification method refers to a set of standards and rules for classifying users according to their steam flow requirements and time characteristic requirements in the user shut-off steam extraction check valve control system.

[0081] The working principle and beneficial effects of the above technical solution are:

[0082] The coefficient determination unit 1 determines the air supply variation coefficient for each time period based on user demand, and the coefficient determination unit 2 determines the temperature variation coefficient based on the air supply variation coefficient;

[0083] Classification unit: divides users into several demand levels based on their steam flow requirements and preset classification methods;

[0084] Parameter acquisition unit: obtains the opening and closing range and sensitivity of each type of steam extraction check valve based on the preset operation manual;

[0085] Parameter setting unit: setting the opening and closing range and sensitivity of the corresponding steam extraction check valve based on the demand level of each user and the opening and closing range and sensitivity of each type of steam extraction check valve;

[0086] Early warning module 2: when the temperature change coefficient is greater than the preset temperature change coefficient, an early warning is issued;

[0087] Regulation control unit: Based on the steam supply coefficient of each time period, the temperature variation coefficient, the demand level of each user, the opening and closing range and sensitivity of each extraction check valve, the regulation strategy is determined to adjust the opening of the extraction check valve.

[0088] Example 7

[0089] Based on the sixth embodiment, the coefficient determination unit 1 includes:

[0090] Based on the user's steam flow demand, user's steam pressure demand and user's time characteristic demand, determine the air supply variation coefficient in the extraction check valve in each time period:

[0091]

[0092] Where, j is the air supply variation coefficient in the extraction check valve, C m is the steam flow coefficient at the minimum relative opening, C d is the steam flow coefficient at the maximum relative opening, γ is the steam expansion coefficient, P1 is the pressure in the extraction check valve before air supply, P2 is the pressure in the extraction check valve after air supply, W1 is the preset maximum flow demand, W2 is the preset minimum flow demand, μ is the compression coefficient of the steam passing through the extraction check valve, ε is the resistance coefficient of the extraction check valve, and ρ is the density of the steam in the extraction check valve.

[0093] The working principle and beneficial effects of the above technical solution are: The air supply variation coefficient in the extraction steam check valve is calculated, and the temperature variation coefficient is determined based on the air supply variation coefficient.

[0094] Example 8

[0095] Based on Example 7, the coefficient determination unit 2 includes:

[0096]

[0097] Wherein, N is the temperature variation coefficient of the extraction check valve, b is the turbulent flux, s is the movement distance of the steam in the extraction check valve, δ is the viscosity coefficient, and β is the diffusion coefficient.

[0098] The working principle and beneficial effects of the above technical solution are: The temperature variation coefficient of the extraction steam check valve is calculated, and compared with the preset rated temperature variation coefficient. When the temperature variation coefficient of the extraction steam check valve is greater than or equal to the rated temperature variation coefficient, there is a problem with the performance of the extraction steam check valve. When the temperature variation coefficient of the extraction steam check valve is less than the rated temperature variation coefficient, the performance of the extraction steam check valve is normal, and the extraction steam check valve and the rotation sensor provided thereon continue to be used, thereby realizing thermal energy management.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device to prevent over-temperature aging of analog feedback of steam extraction check valve in power plant, characterized in that: include: A valve flap fixing base (1), wherein a valve flap rotating shaft (2) is rotatably arranged on the valve flap fixing base (1), a first extended rotating shaft (3) is connected to the valve flap rotating shaft (2) via a lock (4), a second extended rotating shaft (5) is rotatably arranged on one side of a rotation sensor (6), the first extended rotating shaft (3) is fixedly connected to the second extended rotating shaft (5) via a lock (4), and a heat-insulating fixing bracket (7) is fixedly arranged between the valve flap fixing base (1) and the rotation sensor (6).

2. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 1 is characterized in that: Also includes: A data acquisition module is provided, wherein a monitoring sensor is installed in the steam extraction check valve to collect parameters of the steam extraction check valve in real time; Demand analysis module, used to analyze demand parameters input by users; The parameter adjustment module is used to continuously detect the parameters of the extraction steam check valve and adjust the opening of the extraction steam check valve according to demand; Early warning module 1: when the parameters of the extraction steam check valve are greater than or equal to the required parameters input by the user, an early warning is issued.

3. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 2 is characterized in that: The monitoring sensors include: a rotation sensor (6), a temperature sensor, a pressure sensor, and a flow sensor.

4. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 2 is characterized in that: The requirements analysis module includes: Feature acquisition unit: extracts several initial features from the demand parameters input by the user, and analyzes the initial features to obtain several key features; Model building unit: determining the demand forecasting model in a preset feature type-model database based on the feature type of the key feature, and then establishing the demand forecasting model; Demand acquisition unit: inputs the user demand parameters collected in real time into the demand prediction model to obtain several user demands.

5. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 4 is characterized in that: The demand parameters input by the user include: steam flow demand in the extraction check valve, pressure demand in the extraction check valve, temperature demand of the extraction check valve, and operating time characteristic demand of the extraction check valve.

6. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 5 is characterized in that: The parameter adjustment module includes: Coefficient determination unit 1: determining the gas supply change coefficient for each time period based on user demand; Coefficient determination unit 2: determining the temperature variation coefficient based on the air supply variation coefficient; Classification unit: divides users into several demand levels based on their steam flow requirements and preset classification methods; Parameter acquisition unit: obtains the opening and closing range and sensitivity of each type of steam extraction check valve based on the preset operation manual; Parameter setting unit: setting the opening and closing range and sensitivity of the corresponding check valve based on the demand level of each user and the opening and closing range and sensitivity of each type of steam extraction check valve; Early warning module 2: when the temperature change coefficient is greater than the preset temperature change coefficient, an early warning is issued; Regulation control unit: Based on the steam supply coefficient of each time period, the temperature variation coefficient, the demand level of each user, the opening and closing range and sensitivity of each extraction check valve, the regulation strategy is determined to adjust the opening of the extraction check valve.

7. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 6 is characterized in that: Coefficient determination unit 1, including: Based on the user's steam flow demand, user's steam pressure demand and user's time characteristic demand, determine the air supply variation coefficient in the extraction check valve in each time period: Where, j is the air supply variation coefficient in the extraction check valve, C m is the steam flow coefficient at the minimum relative opening, C d is the steam flow coefficient at the maximum relative opening, γ is the steam expansion coefficient, P1 is the pressure in the extraction check valve before air supply, P2 is the pressure in the extraction check valve after air supply, W1 is the preset maximum flow demand, W2 is the preset minimum flow demand, μ is the compression coefficient of the steam passing through the extraction check valve, ε is the resistance coefficient of the extraction check valve, and ρ is the density of the steam in the extraction check valve.

8. The device for preventing over-temperature aging of analog feedback of steam extraction check valve in power plant according to claim 7 is characterized in that: Coefficient determination unit 2, including: Wherein, N is the temperature variation coefficient of the extraction check valve, b is the turbulent flux, s is the movement distance of steam in the extraction check valve, δ is the viscosity coefficient, and β is the diffusion coefficient.

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