A biomass steam turbine control system

Abstract

The present invention relates to the field of steam turbine control, and in particular to a biomass steam turbine control system. The detection module of the present invention obtains steam ultrasonic signals, obtains steam images, obtains valve vibration signals and rotating shaft vibration signals, and obtains steam flow rate. The steam characterization unit obtains steam ultrasonic signals and steam images of steam inlets, calculates steam purity characterization values, and classifies steam. The conversion mechanism analysis unit selects a steam turbine operation strategy according to the steam category, determines whether the filtration meets the standards, or calculates airflow operation characterization parameters, determines whether there are hidden abnormalities inside the steam turbine, obtains valve vibration signals and rotating shaft vibration signals, and determines whether the operation of the steam turbine is abnormal. The present invention reliably monitors the operation status of the steam turbine, makes timely judgments on abnormal operation of the steam turbine, and adjusts the operation of the steam turbine, thereby improving the operation efficiency of the steam turbine.

Description

Technical Field

[0001] The invention relates to the field of steam turbine control, and in particular to a biomass steam turbine control system. Background Art

[0002] A steam turbine is a thermomechanical device that uses the kinetic energy of steam or gas to drive the rotor to rotate, thereby generating power. Its working principle is based on the steam turbine cycle in thermodynamics, including processes such as steam intake, expansion, exhaust and recirculation. Steam turbines are widely used in power plants, petrochemicals, ship power, aircraft propulsion, nuclear power plants and other fields. Different application scenarios require different types and sizes of steam turbines. In order to improve the efficiency and performance of steam turbines, research on steam turbines is increasing.

[0003] Chinese Patent Publication No.: CN116733545A, discloses a steam turbine and a control method for the steam turbine, including a cylinder, the cylinder having a first accommodating chamber, a second accommodating chamber and a rotating shaft. In the embodiment of the present invention, the flow assembly in the steam turbine includes at least two sections: a first flow assembly and a second flow assembly, and the accommodating chambers where the two flow assemblies are located are respectively provided with a first inlet and a second inlet. The first inlet and the second inlet can be selectively opened according to the flow rate of steam entering the steam turbine, so that the flow flow of steam in the flow assembly can be changed with the power change, so that the steam turbine can obtain an ideal flow area and an optimal flow efficiency under various powers, and the steam turbine can operate efficiently within a wider power range.

[0004] However, in the prior art, steam is not classified according to the degree of impurities it contains, and corresponding turbine operating parameters are not selected according to different steam categories. This fails to extend the normal operation time of the turbine and fails to reliably obtain the internal operating status of the turbine, resulting in low turbine operation efficiency. Summary of the invention

[0005] To this end, the present invention provides a biomass turbine control system to overcome the problem in the prior art that steam is not classified according to the degree of impurities contained in the steam, corresponding turbine operating parameters are selected according to different steam categories, the normal operation time of the turbine cannot be extended, and the internal operating status of the turbine cannot be reliably obtained, thereby resulting in low efficiency of the turbine operation.

[0006] To achieve the above object, the present invention provides a biomass steam turbine control system, comprising:

[0007] The detection module includes an ultrasonic detection unit disposed at the steam inlet of the steam turbine for obtaining a steam ultrasonic signal, an image acquisition unit disposed at the steam inlet and steam outlet of the steam turbine for obtaining a steam image, a vibration detection unit disposed on the valve at the steam inlet for obtaining a valve vibration signal, a vibration detection unit disposed on the rotating shaft of the steam turbine for obtaining a rotating shaft vibration signal, and a flow detection unit disposed at the steam outlet for obtaining a steam flow rate;

[0008] The host computer is connected to the steam turbine and the detection module respectively, and includes a steam characterization unit and a conversion mechanism analysis unit.

[0009] The steam characterization unit is used to obtain the steam ultrasonic signal and the steam image of the steam inlet, so as to calculate the steam purity characterization value according to the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image, and classify the steam;

[0010] The conversion mechanism analysis unit is used to select a steam turbine operation strategy according to the steam type, including:

[0011] Adjust the steam flow rate at the steam inlet and determine whether the filtration meets the standards based on the flow rate of steam out of the filter assembly of the steam turbine;

[0012] Or, obtain the steam flow rate of the steam outlet and the steam direction based on the steam image of the steam outlet, calculate the airflow operation characterization parameters, determine whether there are hidden abnormalities inside the turbine, obtain the valve vibration signal and the rotating shaft vibration signal, and determine whether there is any abnormality in the operation of the turbine.

[0013] Furthermore, the steam characterization unit calculates the steam purity characterization value according to formula (1):

[0014] (1)

[0015] In formula (1), E represents the steam purity characterization value, A represents the amplitude of the steam ultrasonic signal, A0 represents the preset amplitude threshold of the steam ultrasonic signal, S represents the chromaticity value of the steam image, and S0 represents the preset chromaticity value threshold of the steam image.

[0016] Furthermore, the steam characterization unit compares the steam purity characterization value with a preset steam purity characterization value comparison threshold value.

[0017] If the steam purity characterization value is less than a preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a high purity class;

[0018] If the steam purity characterization value is greater than or equal to a preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a non-high purity category.

[0019] Furthermore, the conversion mechanism analysis unit selects a steam turbine operation strategy according to the steam type.

[0020] If the steam category is high purity, the conversion mechanism analysis unit obtains the steam flow rate of the steam outlet and the steam direction according to the steam image of the steam outlet, calculates the airflow operation characteristic parameters, determines whether there is a hidden abnormality inside the steam turbine, obtains the valve vibration signal and the rotating shaft vibration signal, and determines whether there is an abnormality in the operation of the steam turbine;

[0021] If the steam category is not a high purity category, the conversion mechanism analysis unit adjusts the steam flow rate at the steam inlet and determines whether the filtration meets the standards based on the flow rate of the steam flowing out of the filter assembly of the steam turbine.

[0022] Furthermore, the conversion mechanism analysis unit adjusts the steam flow rate of the steam inlet according to the steam purity characterization value, wherein the steam purity characterization value is negatively correlated with the steam flow rate of the steam inlet.

[0023] Furthermore, the conversion mechanism analysis unit compares the flow rate of steam flowing out of the filter unit with a preset flow rate comparison threshold value,

[0024] If the flow rate of steam outflowing from the filter unit is less than a preset outflow flow rate comparison threshold, the conversion mechanism analysis unit determines that the filtration does not meet the standard.

[0025] Furthermore, the conversion mechanism analysis unit calculates the airflow operation characteristic parameter according to formula (2):

[0026] (2)

[0027] In formula (2), C represents the airflow operation characteristic parameter, V represents the steam flow rate of the steam outlet, V0 represents the preset steam flow rate threshold of the steam outlet, θ represents the steam angle, and θ0 represents the preset steam angle threshold.

[0028] Furthermore, the conversion mechanism analysis unit compares the airflow operation characteristic parameter with a preset airflow operation characteristic parameter comparison threshold value.

[0029] If the airflow operation characterization parameter is greater than a preset airflow operation characterization parameter comparison threshold, the conversion mechanism analysis unit determines that there is a hidden abnormality inside the turbine.

[0030] Furthermore, the conversion mechanism analysis unit determines whether the operation of the steam turbine is abnormal, including:

[0031] Obtaining the average amplitude of the valve vibration signal within a preset time range and obtaining the average amplitude of the rotating shaft vibration signal within a preset time range, comparing the average amplitude of the valve vibration signal within the preset time range with a preset valve amplitude comparison threshold, and comparing the average amplitude of the rotating shaft vibration signal within the preset time range with a preset rotating shaft amplitude comparison threshold,

[0032] If the first preset condition is met, the conversion mechanism analysis unit determines that the steam turbine operation is abnormal;

[0033] The first preset condition is that the average amplitude of the valve vibration signal within the preset time range is greater than the preset valve amplitude comparison threshold, or the average amplitude of the rotating shaft vibration signal within the preset time range is greater than the preset rotating shaft amplitude comparison threshold.

[0034] Furthermore, it also includes a start-stop module, which is used to stop the operation of the steam turbine when the conversion mechanism analysis unit determines that the filtering does not meet the standards, or when it determines that the operation of the steam turbine is abnormal.

[0035] Compared with the prior art, the detection module of the present invention obtains steam ultrasonic signals, steam images, valve vibration signals and rotating shaft vibration signals, and obtains steam flow rate. The steam characterization unit obtains steam ultrasonic signals and steam images of steam inlets, calculates steam purity characterization values, and classifies steam. The conversion mechanism analysis unit selects a turbine operation strategy according to the steam category, including determining whether the filtration meets the standards, or calculating airflow operation characterization parameters, determining whether there are hidden abnormalities inside the turbine, obtaining valve vibration signals and rotating shaft vibration signals, and determining whether there are abnormalities in the operation of the turbine. The present invention reliably monitors the operating status of the turbine, makes timely judgments on abnormal turbine operation, and adjusts the operation of the turbine, thereby improving the operating efficiency of the turbine.

[0036] In particular, the steam characterization unit of the present invention calculates the steam purity characterization value based on the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image. By ultrasonicating the steam, it is possible to characterize to a certain extent whether the steam contains impurities and the impurity content. Impurities will scatter ultrasonic waves, causing the ultrasonic signal to change, and the chromaticity value of the steam can also characterize to a certain extent whether the steam contains impurities. When the chromaticity value of the steam is significantly different from the chromaticity value of pure steam, it is inferred that the impurity content of the steam is high. By obtaining the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image, the purity of the steam can be reliably characterized, thereby providing data support for the follow-up.

[0037] In particular, the conversion mechanism analysis unit of the present invention adjusts the steam flow rate at the steam inlet according to the steam purity characterization value. When the steam purity characterization value is large, the steam purity is low and the impurity content in the steam is high. Too fast a steam flow rate may increase the filtration load, reduce its processing efficiency, and even cause damage to the filter component. Reducing the steam flow rate can increase the filtration time of the steam in the filter component, so that the filter component has more time and opportunities to capture and remove impurities, thereby improving the filtration efficiency.

[0038] In particular, the conversion mechanism analysis unit of the present invention obtains the steam flow rate of the steam outlet and the steam direction according to the steam image of the steam outlet, and calculates the parameters characterizing the operation of the airflow. The turbine blades are subjected to periodic loads in a working environment of long-term high-speed rotation and impact by high-temperature and high-pressure steam, resulting in fatigue damage of the blade material. This fatigue may manifest as cracks, peeling or deformation on the blade surface. The uneven or concave surface caused by blade fatigue may cause instability in the steam flow. When the steam flows over the damaged blade surface, the flow will be disturbed, and turbulence or vortices may be generated, thereby affecting the flow rate and direction of the steam. By obtaining the steam flow rate and steam direction at the steam outlet, it is possible to characterize to a certain extent whether the blade operation is abnormal, thereby characterizing whether the turbine operation is abnormal, monitor the turbine operation status, make timely judgments on turbine operation abnormalities, and make adjustments to the turbine operation, thereby improving the turbine operation efficiency.

[0039] In particular, the conversion mechanism analysis unit of the present invention obtains the valve vibration signal and the rotating shaft vibration signal to determine whether the turbine operation is abnormal. The presence of impurities may increase the friction of the valve or the rotating shaft, resulting in increased energy loss and increased vibration amplitude. Especially in high-speed turbines, the increase in friction may cause the vibration amplitude to increase significantly. When the blades are damaged, the mass distribution of the blades may change, resulting in rotor imbalance. This imbalance will cause the rotating shaft to vibrate, and the amplitude may increase. By obtaining the valve vibration signal and the rotating shaft vibration signal, the turbine operation status can be monitored, the turbine operation abnormality can be judged in time, and the turbine operation can be adjusted, thereby improving the turbine operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic structural diagram of a biomass steam turbine control system according to an embodiment of the invention;

[0041] Figure 2 It is a structure diagram of the host computer of an embodiment of the invention;

[0042] Figure 3 A logic decision diagram for classifying steam categories for a steam characterization unit of an embodiment of the invention;

[0043] Figure 4 This is a logic determination diagram for determining whether there is a hidden abnormality inside a steam turbine by a conversion mechanism analysis unit according to an embodiment of the invention. DETAILED DESCRIPTION

[0044] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0046] See also Figure 1-Figure 4 As shown, Figure 1 This is a simplified structural diagram of the biomass steam turbine control system of the embodiment of the invention. Figure 2 This is a diagram of the host computer structure of an embodiment of the invention. Figure 3 A steam characterization unit of an embodiment of the invention divides steam into categories according to a logic decision diagram. Figure 4 The conversion mechanism analysis unit of the embodiment of the invention determines whether there is a hidden abnormality logic determination diagram inside the steam turbine. The biomass steam turbine control system of the present invention includes:

[0047] The detection module includes an ultrasonic detection unit disposed at the steam inlet of the steam turbine for obtaining a steam ultrasonic signal, an image acquisition unit disposed at the steam inlet and steam outlet of the steam turbine for obtaining a steam image, a vibration detection unit disposed on the valve at the steam inlet for obtaining a valve vibration signal, a vibration detection unit disposed on the rotating shaft of the steam turbine for obtaining a rotating shaft vibration signal, and a flow detection unit disposed at the steam outlet for obtaining a steam flow rate;

[0048] The host computer is connected to the steam turbine and the detection module respectively, and includes a steam characterization unit and a conversion mechanism analysis unit.

[0049] The steam characterization unit is used to obtain the steam ultrasonic signal and the steam image of the steam inlet, so as to calculate the steam purity characterization value according to the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image, and classify the steam;

[0050] The conversion mechanism analysis unit is used to select a steam turbine operation strategy according to the steam type, including:

[0051] Adjust the steam flow rate at the steam inlet and determine whether the filtration meets the standards based on the flow rate of steam out of the filter assembly of the steam turbine;

[0052] Or, obtain the steam flow rate of the steam outlet and the steam direction based on the steam image of the steam outlet, calculate the airflow operation characterization parameters, determine whether there are hidden abnormalities inside the turbine, obtain the valve vibration signal and the rotating shaft vibration signal, and determine whether there is any abnormality in the operation of the turbine.

[0053] Specifically, the present invention does not limit the specific structure of the steam turbine. It can be understood that the structure of the steam turbine includes:

[0054] The conversion mechanism comprises a steam inlet, a cylinder and a steam outlet, wherein the steam inlet is provided with a valve for adjusting the steam flow rate, and the cylinder comprises an impeller arranged on a rotating shaft so as to be driven to rotate by steam;

[0055] The filter assembly is connected with the conversion mechanism and is arranged at the steam inlet for filtering the steam.

[0056] The steam inlet can be a pipe to guide the steam flow, the cylinder can be cylindrical, the valve can be a gate valve, a stop valve, a regulating valve, etc. to adjust the steam flow rate, the steam outlet can be a pipe to guide the steam flow to the next stage, the material of the rotating shaft can be heat-resistant steel or alloy steel with good high temperature stability and heat resistance, and the blades are curved in shape to interact with the steam.

[0057] The filter assembly can be single-stage filtration or multi-stage filtration, and the components of the filter mechanism are resistant to high temperature and corrosion and have certain strength and hardness. This is the prior art and will not be described in detail.

[0058] Specifically, the steam entering the steam turbine in the present invention is generated by using biomass as fuel.

[0059] Specifically, the present invention does not limit the specific structure of the detection module. The ultrasonic detection unit may be an ultrasonic sensor, the image acquisition unit may be an industrial CCD depth camera, the vibration detection unit may be a vibration sensor, and the flow detection unit may be a flow meter. This is the prior art and will not be described in detail.

[0060] Specifically, the present invention does not limit the specific structure of the host computer. The steam characterization unit and the conversion mechanism analysis unit can be composed of logic components or a combination of logic components. The logic components include a field programmable processor, a computer or a microprocessor in a computer. This is a prior art and will not be repeated here.

[0061] Specifically, the present invention does not limit the specific structure of the start-stop module, which can obtain the judgment result of the conversion mechanism analysis unit and control the operation and stop of the turbine. It can be composed of logic components or a combination of logic components. This is the prior art and will not be repeated.

[0062] Specifically, the steam characterization unit calculates the steam purity characterization value according to formula (1):

[0063] (1)

[0064] In formula (1), E represents the steam purity characterization value, A represents the amplitude of the steam ultrasonic signal, A0 represents the preset amplitude threshold of the steam ultrasonic signal, S represents the chromaticity value of the steam image, and S0 represents the preset chromaticity value threshold of the steam image.

[0065] In this embodiment, A0 and S0 are measured in advance by experiments. The ultrasonic signal amplitude and chromaticity value of steam with an impurity content less than 1% are obtained several times in advance, and the ultrasonic signal amplitude average value Ae and the chromaticity value average value Se are calculated. It is assumed that A0=a×Ae, a is the ultrasonic signal amplitude coefficient, 0.9<a<1.1, and S0=b×Se, b is the chromaticity value coefficient, 0.9<b<1.1.

[0066] Specifically, the steam characterization unit of the present invention calculates the steam purity characterization value based on the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image. By ultrasonicating the steam, it is possible to characterize to a certain extent whether the steam contains impurities and the impurity content. Impurities will scatter ultrasonic waves, causing the ultrasonic signal to change, and the chromaticity value of the steam can also characterize to a certain extent whether the steam contains impurities. When the chromaticity value of the steam is significantly different from the chromaticity value of pure steam, it is inferred that the impurity content of the steam is high. By obtaining the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image, the purity of the steam can be reliably characterized, thereby providing data support for the follow-up.

[0067] Specifically, the steam characterization unit compares the steam purity characterization value with a preset steam purity characterization value comparison threshold value.

[0068] If the steam purity characterization value is less than a preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a high purity class;

[0069] If the steam purity characterization value is greater than or equal to a preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a non-high purity category.

[0070] In this embodiment, the preset steam purity characterization value comparison threshold E0 is selected within the range of [0.1, 0.2].

[0071] Specifically, the conversion mechanism analysis unit selects a steam turbine operation strategy according to the steam type.

[0072] If the steam category is high purity, the conversion mechanism analysis unit obtains the steam flow rate of the steam outlet and the steam direction according to the steam image of the steam outlet, calculates the airflow operation characteristic parameters, determines whether there is a hidden abnormality inside the steam turbine, obtains the valve vibration signal and the rotating shaft vibration signal, and determines whether there is an abnormality in the operation of the steam turbine;

[0073] If the steam category is not a high purity category, the conversion mechanism analysis unit adjusts the steam flow rate at the steam inlet and determines whether the filtration meets the standards based on the flow rate of the steam flowing out of the filter assembly of the steam turbine.

[0074] Specifically, the conversion mechanism analysis unit adjusts the steam flow rate of the steam inlet according to the steam purity characterization value, wherein the steam purity characterization value is positively correlated with the steam flow rate of the steam inlet.

[0075] In this embodiment, optionally,

[0076] E0<E<0.25, steam flow rate at steam inlet Vz1=Vz0-△Vz1;

[0077] 0.25≤E, steam flow rate at steam inlet Vz2=Vz0-△Vz2;

[0078] Vz0 is the steam flow rate at the initial steam inlet, △Vz1 is the first steam flow rate adjustment amount, △Vz2 is the second steam flow rate adjustment amount, 0.1Vz0<△Vz1<△Vz2<0.3Vz0.

[0079] Specifically, the conversion mechanism analysis unit of the present invention adjusts the steam flow rate at the steam inlet according to the steam purity characterization value. When the steam purity characterization value is large, the steam purity is low and the impurity content in the steam is high. A too fast steam flow rate may increase the filtration load, reduce its processing efficiency, and even cause damage to the filter component. Reducing the steam flow rate can increase the filtration time of the steam in the filter component, so that the filter component has more time and opportunities to capture and remove impurities, thereby improving the filtration efficiency.

[0080] Specifically, the conversion mechanism analysis unit compares the flow rate of steam flowing out of the filter unit with a preset flow rate comparison threshold.

[0081] If the flow rate of steam outflowing from the filter unit is less than a preset outflow flow rate comparison threshold, the conversion mechanism analysis unit determines that the filtration does not meet the standard.

[0082] In this embodiment, when the filter assembly of the steam turbine works normally, the flow rate of steam flowing out of the filter assembly corresponding to different steam flow rates at the steam inlet is measured in advance and recorded as the preset outflow flow rate comparison threshold.

[0083] Specifically, the conversion mechanism analysis unit calculates the airflow operation characteristic parameter according to formula (2):

[0084] (2)

[0085] In formula (2), C represents the airflow operation characteristic parameter, V represents the steam flow rate of the steam outlet, V0 represents the preset steam flow rate threshold of the steam outlet, θ represents the steam angle, and θ0 represents the preset steam angle threshold.

[0086] In this embodiment, V0 and θ0 are measured in advance by experiments, and the steam flow rate Ve and steam angle θe at the steam outlet when the turbine is operating normally are obtained in advance. It is assumed that V0=c×Ve, c is the steam outlet flow rate coefficient, 0.9<c<1.1, and θ0=d×θe, d is the steam angle coefficient, 0.9<d<1.1.

[0087] In this embodiment, the specific method of identifying the steam direction is not limited. The steam direction can be identified and analyzed by image analysis software on the steam image. For example, the steam image can be a depth image. The steam contour in the steam image can be pre-identified, and the three-dimensional coordinates of several collection points are extracted from the steam contour. A number of vectors are constructed with the steam outlet center point as the starting point and each collection point as the end point. The several vectors are summed to obtain the steam direction vector. The direction corresponding to the steam direction vector is determined as the steam direction. The angle between the steam direction vector and the plane where the steam outlet is located is the steam angle, which will not be repeated here.

[0088] Specifically, the conversion mechanism analysis unit of the present invention obtains the steam flow rate of the steam outlet and the steam direction according to the steam image of the steam outlet, and calculates the airflow operation characterization parameters. The turbine blades are subjected to periodic loads in a working environment of long-term high-speed rotation and impact of high-temperature and high-pressure steam, resulting in fatigue damage of the blade material. This fatigue may manifest as cracks, peeling or deformation on the blade surface. The uneven or concave surface caused by blade fatigue may cause instability in steam flow. When steam flows over the damaged blade surface, the flow will be disturbed, and turbulence or vortexes may be generated, thereby affecting the flow rate and direction of the steam. By obtaining the steam flow rate and steam direction of the steam outlet, it is possible to characterize whether the blade operation is abnormal to a certain extent, thereby characterizing whether the turbine operation is abnormal, monitor the turbine operation status, make timely judgments on turbine operation abnormalities, and make adjustments to the turbine operation, thereby improving the turbine operation efficiency.

[0089] Specifically, the conversion mechanism analysis unit compares the airflow operation characteristic parameter with a preset airflow operation characteristic parameter comparison threshold value.

[0090] If the airflow operation characterization parameter is greater than a preset airflow operation characterization parameter comparison threshold, the conversion mechanism analysis unit determines that there is a hidden abnormality inside the turbine.

[0091] In this embodiment, the preset airflow operation characterization parameter comparison threshold is selected within the range of [0.1, 0.15].

[0092] Specifically, when the conversion mechanism analysis unit determines that there is a hidden abnormality inside the steam turbine, it obtains the amplitude average value of the valve vibration signal within a preset time range and the amplitude average value of the rotating shaft vibration signal within a preset time range, compares the amplitude average value of the valve vibration signal within the preset time range with a preset valve amplitude comparison threshold, and compares the amplitude average value of the rotating shaft vibration signal within the preset time range with a preset rotating shaft amplitude comparison threshold. If a first preset condition is met, the conversion mechanism analysis unit determines that an abnormality has occurred in the operation of the steam turbine. The first preset condition is that the amplitude average value of the valve vibration signal within the preset time range is greater than the preset valve amplitude comparison threshold, or the amplitude average value of the rotating shaft vibration signal within the preset time range is greater than the preset rotating shaft amplitude comparison threshold.

[0093] In this embodiment, the preset time range is selected within the range of [20s, 40s], the preset valve amplitude comparison threshold and the preset rotating shaft amplitude comparison threshold are pre-measured in experiments, and during the normal operation of the steam turbine, the valve amplitude and the rotating shaft amplitude are obtained several times, and the valve amplitude average value and the rotating shaft amplitude average value are calculated. The preset valve amplitude comparison threshold = e×valve amplitude average value, e is the valve amplitude average value coefficient, 0.9<e<1.1, the preset rotating shaft amplitude comparison threshold = f×rotating shaft amplitude average value, f is the rotating shaft amplitude average value coefficient, 0.9<f<1.1.

[0094] Specifically, it also includes a start-stop module, which is used to stop the operation of the steam turbine when the conversion mechanism analysis unit determines that the filtering does not meet the standards, or when it determines that the operation of the steam turbine is abnormal.

[0095] Specifically, the conversion mechanism analysis unit of the present invention obtains the valve vibration signal and the rotating shaft vibration signal to determine whether the turbine operation is abnormal. The presence of impurities may increase the friction of the valve or the rotating shaft, resulting in increased energy loss and increased vibration amplitude. Especially in high-speed turbines, the increase in friction may cause the vibration amplitude to increase significantly. When the blades are damaged, the mass distribution of the blades may change, resulting in rotor imbalance. This imbalance will cause the rotating shaft to vibrate, and the amplitude may increase. By obtaining the valve vibration signal and the rotating shaft vibration signal, the turbine operation status can be monitored, the turbine operation abnormality can be judged in time, and the turbine operation can be adjusted, thereby improving the turbine operation efficiency.

[0096] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A biomass steam turbine control system, characterized in that: include: The detection module includes an ultrasonic detection unit disposed at the steam inlet of the steam turbine for obtaining a steam ultrasonic signal, an image acquisition unit disposed at the steam inlet and steam outlet of the steam turbine for obtaining a steam image, a vibration detection unit disposed on the valve at the steam inlet for obtaining a valve vibration signal, a vibration detection unit disposed on the rotating shaft of the steam turbine for obtaining a rotating shaft vibration signal, and a flow detection unit disposed at the steam outlet for obtaining a steam flow rate; The host computer is connected to the steam turbine and the detection module respectively, and includes a steam characterization unit and a conversion mechanism analysis unit. The steam characterization unit is used to obtain the steam ultrasonic signal and the steam image of the steam inlet, so as to calculate the steam purity characterization value according to the amplitude of the steam ultrasonic signal and the chromaticity value of the steam image, and classify the steam; The steam characterization unit compares the steam purity characterization value with a preset steam purity characterization value comparison threshold value, If the steam purity characterization value is less than a preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a high purity class; If the steam purity characterization value is greater than or equal to the preset steam purity characterization value comparison threshold, the steam characterization unit classifies the steam into a non-high purity category; The conversion mechanism analysis unit is used to select a steam turbine operation strategy according to the steam type, including: If the steam category is not high purity, the steam flow rate at the steam inlet is adjusted, and the filtration is judged to be in compliance with the standard according to the flow rate of the steam out of the filter assembly of the steam turbine; If the steam category is high purity, the steam flow rate of the steam outlet is obtained, and the steam direction is obtained based on the steam image of the steam outlet, the airflow operation characterization parameters are calculated, and it is determined whether there are hidden abnormalities inside the turbine. The valve vibration signal and the rotating shaft vibration signal are obtained to determine whether there are abnormalities in the operation of the turbine.

2. The biomass steam turbine control system according to claim 1, characterized in that: The steam characterization unit calculates the steam purity characterization value according to formula (1): (1) In formula (1), E represents the steam purity characterization value, A represents the amplitude of the steam ultrasonic signal, A0 represents the preset amplitude threshold of the steam ultrasonic signal, S represents the chromaticity value of the steam image, and S0 represents the preset chromaticity value threshold of the steam image.

3. The biomass steam turbine control system according to claim 1, characterized in that: The conversion mechanism analysis unit adjusts the steam flow rate of the steam inlet according to the steam purity characterization value, wherein the steam purity characterization value is negatively correlated with the steam flow rate of the steam inlet.

4. The biomass steam turbine control system according to claim 1, characterized in that: The conversion mechanism analysis unit compares the flow rate of steam outflowing from the filter unit with a preset outflow flow rate comparison threshold value, If the flow rate of steam outflowing from the filter unit is less than a preset outflow flow rate comparison threshold, the conversion mechanism analysis unit determines that the filtration does not meet the standard.

5. The biomass steam turbine control system according to claim 1, characterized in that: The conversion mechanism analysis unit calculates the airflow operation characteristic parameter according to formula (2): (2) In formula (2), C represents the airflow operation characteristic parameter, V represents the steam flow rate of the steam outlet, V0 represents the preset steam flow rate threshold of the steam outlet, θ represents the steam angle, and θ0 represents the preset steam angle threshold.

6. The biomass steam turbine control system according to claim 5, characterized in that: The conversion mechanism analysis unit compares the airflow operation characteristic parameter with a preset airflow operation characteristic parameter comparison threshold value, If the airflow operation characterization parameter is greater than a preset airflow operation characterization parameter comparison threshold, the conversion mechanism analysis unit determines that there is a hidden abnormality inside the turbine.

7. The biomass steam turbine control system according to claim 1, characterized in that: The conversion mechanism analysis unit determines whether the turbine operation is abnormal by: Obtaining the average amplitude of the valve vibration signal within a preset time range and obtaining the average amplitude of the rotating shaft vibration signal within a preset time range, comparing the average amplitude of the valve vibration signal within the preset time range with a preset valve amplitude comparison threshold, and comparing the average amplitude of the rotating shaft vibration signal within the preset time range with a preset rotating shaft amplitude comparison threshold, If the first preset condition is met, the conversion mechanism analysis unit determines that the steam turbine operation is abnormal; The first preset condition is that the average amplitude of the valve vibration signal within the preset time range is greater than the preset valve amplitude comparison threshold, or the average amplitude of the rotating shaft vibration signal within the preset time range is greater than the preset rotating shaft amplitude comparison threshold.

8. The biomass steam turbine control system according to claim 1, characterized in that: It also includes a start-stop module, which is used to stop the operation of the steam turbine when the conversion mechanism analysis unit determines that the filtering does not meet the standards, or determines that the operation of the steam turbine is abnormal.

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