Steam gas-liquid separator and liquid level real-time monitoring method thereof

Abstract

The invention relates to the technical field of liquid level measurement, in particular to a steam gas-liquid separator and a real-time liquid level monitoring method thereof, and the method comprises the steps: dividing an echo signal into a liquid level echo signal and a plurality of positioning echo signals; determining the electromagnetic average speed of each positioning echo signal in the time period; obtaining electromagnetic echo signals, and determining the correction speed of electromagnetic waves based on the dispersion degree of the electromagnetic echo signals and the average distribution condition of the electromagnetic average speed of all the positioning echo signals in the time period, and determining the liquid level height of the steam gas-liquid separator at the current moment by combining the length of the liquid level echo signal, the sampling frequency, the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between the adjacent positioning points. By analyzing the influence of the non-uniform distribution of the steam in the separator on the propagation velocity of the electromagnetic waves, the measurement precision of the liquid level height in the steam gas-liquid separator is improved.

Description

Technical Field

[0001] The present application relates to the technical field of liquid level measurement, and in particular to a steam gas-liquid separator and a real-time liquid level monitoring method thereof. Background Art

[0002] The steam gas-liquid separator needs to be tested for liquid level in real time during use to ensure a stable liquid level in order to maintain the output liquid level. Due to the harsh working conditions such as high temperature, high pressure and high saturated steam inside the steam gas-liquid separator, a guided wave radar level meter is usually used as a measuring device to reduce the impact of harsh conditions on the measurement results.

[0003] Guided wave radar level meters are based on the characteristic that guided waves will reflect and return when they touch the liquid surface. The reflection time of the guided waves is measured to determine the distance from the liquid surface to the measuring point, and then the liquid level is obtained. However, due to the presence of steam in the tank, the steam will affect the propagation speed of the guided waves inside the waveguide rod. Therefore, the measured liquid level will be affected by the steam, which will lead to errors in the liquid level measurement. In response to the influence of steam, the existing liquid level correction method sets a reference point on the waveguide rod, estimates the guided wave velocity through the reference data, and then completes the compensation. This method does not fully consider the irregular distribution of steam in the steam-liquid separator. It first assumes that the steam distribution inside the separator is uniform before correcting the liquid level measurement data, thereby reducing the accuracy of the liquid level measurement in the steam-liquid separator. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a steam gas-liquid separator and a real-time liquid level monitoring method thereof to solve the existing problems.

[0005] In a first aspect, an embodiment of the present application provides a method for real-time monitoring of liquid level in a steam gas-liquid separator, the method comprising the following steps: The guided wave radar level meter sends electromagnetic waves to the waveguide rod in the steam gas-liquid separator, and obtains the echo signal at the current moment in the guided wave radar level meter, wherein there are multiple positioning points distributed at equal intervals on the waveguide rod; Obtaining the liquid surface echo moment and all positioning echo moments in the echo signal based on the extreme value distribution in the echo signal; dividing the echo signal into a liquid surface echo signal and a plurality of positioning echo signals based on the liquid surface echo moment and all positioning echo moments; Based on the length of each positioning echo signal and the preset sampling frequency, combined with the interval between adjacent positioning points, the electromagnetic average speed of each positioning echo signal is determined; based on the similarity between each positioning echo signal and the liquid surface echo signal, the speed distribution weight of each positioning echo signal is determined, and combined with the electromagnetic average speed, the speed correction term of the electromagnetic wave is determined; The echo signal between the first positioning echo moment and the liquid surface echo moment is recorded as an electromagnetic echo signal, and the corrected speed of the electromagnetic wave is determined based on the discrete degree of all elements in the electromagnetic echo signal and the average distribution of the electromagnetic average speed of all positioning echo signals; Based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid liquid surface is determined, and combined with the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between adjacent positioning points, the liquid level of the steam gas-liquid separator at the current moment is determined.

[0006] Preferably, the step of acquiring the liquid surface echo moment and all positioning echo moments in the echo signal includes: The echo signal is used as the input of the extreme value detection algorithm, and all the maximum values ​​in the echo signal are output; The first maximum value greater than the preset threshold is recorded as the positioning echo intensity, and the upper limit of interval D is set to the product of the first preset value and the positioning echo intensity, and the lower limit is set to the product of the second preset value and the positioning echo intensity; If the maximum value is in interval D, the time corresponding to the maximum value in the echo signal is recorded as the positioning echo time, and the time corresponding to the maximum value after the last positioning echo time in the echo signal is recorded as the liquid surface echo time, where the first preset value is greater than the second preset value.

[0007] Preferably, the step of dividing the echo signal into a liquid surface echo signal and a plurality of positioning echo signals comprises: The echo signals between the moment when the guided wave radar level meter starts to receive the echo signal and the moment of the first positioning echo, as well as the echo signals between two adjacent positioning echo moments, are all recorded as positioning echo signals; the echo signal between the moment of the last positioning echo and the moment of the liquid surface echo is recorded as the liquid surface echo signal.

[0008] Preferably, the electromagnetic average velocity of each positioning echo signal is a product of the length of each positioning echo signal, a preset sampling frequency and an interval between adjacent positioning points.

[0009] Preferably, the velocity distribution weight of each positioning echo signal is a normalized value of the similarity between each positioning echo signal and the liquid surface echo signal.

[0010] Preferably, the velocity correction term of the electromagnetic wave is the cumulative sum of the products of the velocity distribution weights of all positioning echo signals and the corresponding electromagnetic average velocity.

[0011] Preferably, the method for determining the speed correction weight of the electromagnetic wave is: Calculate the coefficient of variation of all elements in the electromagnetic echo signal. If the coefficient of variation is less than 1, the speed correction weight of the electromagnetic wave is equal to the coefficient of variation. Otherwise, the speed correction weight of the electromagnetic wave is equal to 1. Correction speed of electromagnetic waves The expression is: ; In the formula, It represents the mean value of the electromagnetic average velocity of all positioning echo signals; Represents the speed correction weight of electromagnetic waves; Represents the velocity correction term of electromagnetic waves.

[0012] Preferably, the expression for the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid level is: ; In the formula, Indicates the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid level; Indicates the length of the liquid surface echo signal; F indicates the preset sampling frequency.

[0013] Preferably, the expression for the liquid level height of the steam gas-liquid separator at the current moment is: ; In the formula, Indicates the liquid level of the steam gas-liquid separator at the current moment; It represents the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator; H represents the number of all positioning points on the waveguide rod; d represents the interval between adjacent positioning points.

[0014] In a second aspect, an embodiment of the present application further provides a steam gas-liquid separator, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of a method for real-time monitoring of the liquid level of a steam gas-liquid separator as described above are implemented.

[0015] An embodiment of the present application provides a steam gas-liquid separator and a method for real-time monitoring of its liquid level, the method comprising the following steps: This application has at least the following beneficial effects: The present application adopts an extreme value detection algorithm to obtain the liquid surface echo moment and all positioning echo moments in the echo signal, and the liquid surface echo moment is located after the last positioning echo moment; based on the liquid surface echo moment and all positioning echo moments, the echo signal is divided into a liquid surface echo signal and a plurality of positioning echo signals, which has the beneficial effect of accurately distinguishing the liquid surface echo signal from the positioning echo signal, and can more accurately locate the liquid level height, thereby improving the accuracy of liquid level measurement; The present application determines the electromagnetic average velocity of each positioning echo signal based on the length of each positioning echo signal and the preset sampling frequency, combined with the interval between adjacent positioning points; determines the velocity distribution weight of each positioning echo signal based on the similarity between each positioning echo signal and the liquid surface echo signal, and determines the velocity correction term of the electromagnetic wave in combination with the electromagnetic average velocity. The beneficial effect is that the actual propagation velocity of the electromagnetic wave in the waveguide rod can be more accurately reflected, and the liquid surface height can be more accurately calculated, thereby improving the accuracy of liquid level measurement; In the present application, the echo signal between the first positioning echo moment and the liquid surface echo moment is recorded as an electromagnetic echo signal, and the speed correction weight of the electromagnetic wave is determined based on the discreteness of the electromagnetic echo signal. The correction speed of the electromagnetic wave is determined in combination with the average distribution of the electromagnetic average speed of all positioning echo signals. The beneficial effect is that the influence of the uneven distribution of steam in the separator on the propagation speed of the electromagnetic wave is fully considered, and the actual propagation speed of the electromagnetic wave in the waveguide rod can be more accurately reflected, thereby improving the accuracy of the liquid level measurement. The present application determines the distance between the positioning point corresponding to the last positioning echo moment and the steam-liquid liquid surface based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, and determines the liquid level of the steam-liquid separator at the current moment in combination with the distance from the electromagnetic wave emission position to the bottom of the steam-liquid separator and the interval between adjacent positioning points, thereby improving the accuracy of measuring the liquid level in the steam-liquid separator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A flow chart of the steps of a method for real-time monitoring of the liquid level of a steam gas-liquid separator provided in one embodiment of the present application; Figure 2 A schematic diagram of echo signals before and after filtering provided by an embodiment of the present application; Figure 3 A schematic diagram of a speed correction term extraction process provided by an embodiment of the present application; Figure 4 A schematic diagram of a corrected velocity extraction process of an electromagnetic wave provided in one embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of a steam gas-liquid separator and a real-time liquid level monitoring method thereof proposed in accordance with the present application, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0020] The specific scheme of a steam gas-liquid separator and a real-time liquid level monitoring method thereof provided by the present application is described in detail below with reference to the accompanying drawings.

[0021] An embodiment of the present application provides a steam gas-liquid separator and a real-time monitoring method for its liquid level. Specifically, the following steam gas-liquid separator and a real-time monitoring method for its liquid level are provided. Figure 1 , the method comprises the following steps: Step S1: Send electromagnetic waves to the waveguide rod in the steam gas-liquid separator through the guided wave radar level meter, and obtain the echo signal at the current moment in the guided wave radar level meter.

[0022] The signal generating module of the guided wave radar level meter sends electromagnetic waves to the waveguide rod inserted into the steam gas-liquid separator, and the signal receiving module of the guided wave radar level meter receives the echo signal.

[0023] Among them, positioning points are installed at equal intervals on the waveguide rod. The distance from the positioning points to the position where the electromagnetic wave is emitted is fixed. The positioning points will reflect part of the guided waves. The guided waves reflected by the positioning points can be used to analyze the guided wave velocity, and then the liquid level measurement results can be corrected.

[0024] The echo signal at the current moment is obtained in the signal receiving module of the guided wave radar level meter, and the preset sampling frequency is set to F. The obtained echo signal is a vector, and each element in the vector represents the intensity of the echo signal at the corresponding moment.

[0025] It should be noted that the preset sampling frequency F and the interval between adjacent positioning points are both manually set. In this embodiment, the preset sampling frequency F is 6 GHz, and the interval between adjacent positioning points is 1 m. The implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0026] Step S2: based on the extreme value distribution in the echo signal, obtain the liquid surface echo moment and all positioning echo moments in the echo signal, the liquid surface echo moment is located after the last positioning echo moment; based on the liquid surface echo moment and all positioning echo moments, divide the echo signal into a liquid surface echo signal and multiple positioning echo signals.

[0027] The positioning point of the waveguide rod in the air and the steam gas-liquid surface will reflect a certain amount of echo, which appears as the maximum value point of the signal in the echo signal. Therefore, this embodiment adopts the extreme value detection algorithm to obtain the positioning point in the air and the steam gas-liquid information. Specifically: When using the extreme value detection algorithm, it is necessary to eliminate the interference caused by high-frequency jitter of the data in the echo signal. Therefore, a filtering algorithm is used to eliminate the interference caused by high-frequency jitter of the data in the echo signal.

[0028] It should be noted that there are many commonly used filtering algorithms. In this embodiment, a mean filtering algorithm is used to eliminate interference caused by high-frequency data jitter in the echo signal. Implementers can also use other filtering algorithms such as Gaussian filtering and median filtering. This embodiment does not impose any special restrictions on the selection of filtering algorithms.

[0029] Among them, mean filtering is a well-known technology in the field of data processing, and its specific principle will not be repeated here.

[0030] Further, the echo signal is used as the input of the extreme value detection algorithm, and all the maximum values ​​in the echo signal are output; The first maximum value greater than the preset threshold is recorded as the positioning echo intensity, and the upper limit of interval D is set to the product of the first preset value and the positioning echo intensity, and the lower limit is set to the product of the second preset value and the positioning echo intensity (Note: Since the positioning point is usually a point with a large impedance change, the reflected signal intensity is relatively high, and the maximum value can be identified based on the signal strength); The value of the preset threshold is manually set. In this embodiment, the value of the preset threshold is 5000 mW. The implementer can also set it by himself according to the specific situation. This embodiment does not impose any special restrictions.

[0031] If the maximum value is in interval D, the time corresponding to the maximum value in the echo signal is recorded as the positioning echo time, and the time corresponding to the maximum value after the last positioning echo time in the echo signal is recorded as the liquid surface echo time, where the first preset value is greater than the second preset value.

[0032] It should be noted that the values ​​of the first preset value and the second preset value are both manually set. In this embodiment, the value of the first preset value is 1.2, and the value of the second preset value is 0.9. The implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0033] It should be understood that the positioning echo time actually refers to the time when the positioning point on the waveguide rod located in the air reflects the echo, and the liquid surface echo time refers to the time when the steam-liquid surface reflects the echo.

[0034] Among them, the extreme value detection algorithm is a well-known technology, and the specific process of obtaining the maximum value point is not repeated here.

[0035] Preferably, the schematic diagram of the echo signal before and after filtering provided in this embodiment is as follows: Figure 2 As shown, Figure 2 Figure a in the middle shows the echo signal before filtering, where the signal with higher signal strength is the positioning echo signal reflected by the positioning point on the waveguide rod, and the last peak with higher signal strength is the liquid surface echo signal; Figure 2 Figure b in the middle shows the echo signal after filtering, where the signal with higher signal intensity in the echo signal is the positioning echo signal reflected by the positioning point on the waveguide rod, and the last peak with higher signal intensity is the liquid surface echo signal. Compared with Figure a, it eliminates the influence of high-frequency fluctuations in the data in the echo signal. In Figures a and b, the horizontal axis represents the number of sampling points, and the vertical axis represents the signal strength in mW.

[0036] Furthermore, based on the liquid surface echo moment and all positioning echo moments, the echo signal is divided into a liquid surface echo signal and multiple positioning echo signals. Specifically, the echo signal between the moment when the guided wave radar level meter starts to receive the echo signal and the moment of the first positioning echo, as well as the echo signal between two adjacent positioning echo moments, are all recorded as positioning echo signals; the echo signal between the last positioning echo moment and the liquid surface echo moment is recorded as a liquid surface echo signal.

[0037] It is particularly noted that usually the electromagnetic wave emission position will not coincide with the steam-liquid level, and there is a minimum distance between the two. In this embodiment, the distance is 5 meters, which means that there are at least 4 positioning points (when the liquid level position coincides with the 5th positioning point, there are 4 positioning points).

[0038] Step S3: Based on the length of each positioning echo signal and the preset sampling frequency, combined with the interval between adjacent positioning points, determine the electromagnetic average velocity of each positioning echo signal; based on the similarity between each positioning echo signal and the liquid surface echo signal, determine the velocity distribution weight of each positioning echo signal, and determine the velocity correction item of the electromagnetic wave in combination with the electromagnetic average velocity.

[0039] When measuring the liquid level in a steam environment, the existing guided wave radar level meter considers the speed of the electromagnetic wave in the waveguide rod to be the same throughout the whole process. When the guided wave radar level meter is used to measure the liquid level in a steam gas-liquid separator filled with steam, the steam around the waveguide rod will cause the speed of the electromagnetic wave inside the waveguide rod to change. When the electromagnetic wave speed changes, a certain reflection signal will be generated. The reflection signal is included in the echo signal, which may affect the speed of the electromagnetic wave in the waveguide rod, thereby causing liquid level measurement errors. Therefore, the speed of the electromagnetic wave can be corrected by analyzing the changes in the echo signal, specifically: (1) Since the position of the positioning point is fixed and the steam is randomly distributed in the steam gas-liquid separator, the steam is uniformly distributed in space as a whole. However, due to the continuous flow of steam in the steam gas-liquid separator, the steam distribution is uneven locally. The steam density affects the propagation speed of the electromagnetic wave in the waveguide, which in turn leads to different average propagation speeds of the electromagnetic wave at different positioning points.

[0040] Therefore, based on the length of each positioning echo signal and the preset sampling frequency, combined with the interval between adjacent positioning points, the electromagnetic average velocity of each positioning echo signal is determined to characterize the propagation velocity information of the electromagnetic wave in the waveguide rod, specifically: The length of each positioning echo signal is counted, and the result of multiplying the length of each positioning echo signal, the preset sampling frequency and the interval between adjacent positioning points is used as the electromagnetic average speed of each positioning echo signal.

[0041] (2) The positioning echo signal contains the speed change information of the electromagnetic wave when it propagates at different positioning points, while the liquid surface echo signal contains the speed change information of the electromagnetic wave from the last positioning echo moment to the liquid surface echo moment. Therefore, the greater the similarity between the liquid surface echo signal and the positioning echo signal, the more similar the steam distribution between the two is, and the more similar the propagation speed change of the electromagnetic wave in the two propagation paths is.

[0042] Therefore, based on the similarity between each positioning echo signal and the liquid surface echo signal, the velocity distribution weight of each positioning echo signal is determined, specifically: The normalized value of the similarity between each positioning echo signal and the liquid surface echo signal is used as the velocity distribution weight of each positioning echo signal; It should be noted that there are many methods for calculating the similarity between signals. In this embodiment, the cosine similarity between each positioning echo signal and the liquid surface echo signal is calculated to measure the similarity between the signals. The implementer may also use other methods for measuring the similarity between signals, such as the inverse of the Euclidean distance. This embodiment does not impose any special restrictions on the selection of the method for measuring the similarity between signals.

[0043] The calculation method of cosine similarity is a well-known technology, and its specific calculation steps are not repeated here.

[0044] (3) The larger the velocity distribution weight, the closer the average velocity of the electromagnetic wave in the period corresponding to the liquid surface echo signal is to the average velocity of the electromagnetic wave in the period corresponding to the positioning echo signal, and the more the average velocity of the electromagnetic wave in the period corresponding to the positioning echo signal should be used to represent the average velocity of the electromagnetic wave in the period corresponding to the liquid surface echo signal. Therefore, based on the velocity distribution weight of each positioning echo signal and combined with the electromagnetic average velocity, the velocity correction term of the electromagnetic wave is determined, which is specifically: The velocity correction term of the electromagnetic wave is the cumulative sum of the product of the velocity distribution weights of all positioning echo signals and the corresponding electromagnetic average velocity.

[0045] According to the speed correction term of the electromagnetic wave, it can be understood that the greater the speed distribution weight, the closer the average speed of the reflection sequence of the electromagnetic wave in the corresponding segment of the liquid surface echo signal is to the average speed of the electromagnetic wave in the corresponding period of the positioning echo signal, the more the average speed of the electromagnetic wave in the corresponding period of the positioning echo signal should be used to represent the average speed of the electromagnetic wave in the corresponding period of the liquid surface echo signal, and the larger the obtained speed correction term of the electromagnetic wave; conversely, the smaller the speed distribution weight, the closer the average speed of the electromagnetic wave in the corresponding period of the liquid surface echo signal is to the average speed of the electromagnetic wave in the corresponding period of the positioning echo signal, and the smaller the obtained speed correction term of the electromagnetic wave.

[0046] Preferably, the speed correction term extraction process diagram provided in this embodiment is as follows: Figure 3 shown.

[0047] Step S4: record the echo signal between the first positioning echo moment and the liquid surface echo moment as an electromagnetic echo signal, and determine the correction speed of the electromagnetic wave based on the discrete degree of all elements in the electromagnetic echo signal and the average distribution of the electromagnetic average speed of all positioning echo signals; determine the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid surface based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, and determine the liquid level of the steam gas-liquid separator at the current moment in combination with the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between adjacent positioning points.

[0048] The speed obtained by regarding the propagation speed of the electromagnetic wave in the waveguide rod as a uniform speed has a certain error; the speed correction term takes into account the uneven distribution of steam. The electromagnetic wave is not uniform in the waveguide rod. Therefore, based on the discrete degree of all elements in the electromagnetic echo signal, the speed correction weight of the electromagnetic wave is determined, and the corrected speed of the electromagnetic wave is determined in combination with the average distribution of the electromagnetic average speed of all positioning echo signals. Based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid liquid surface is determined, and the liquid level of the steam gas-liquid separator at the current moment is determined in combination with the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between adjacent positioning points. The measurement error caused by the average speed is eliminated through the speed correction term, thereby eliminating the calculation error caused by the traditional liquid level measurement method. Specifically: (1) The echo signal between the first positioning echo moment and the liquid surface echo moment is recorded as the electromagnetic echo signal; The coefficient of variation of all elements in the electromagnetic echo signal is calculated. If the coefficient of variation is less than 1, the velocity correction weight of the electromagnetic wave is set equal to the coefficient of variation. Conversely, if the coefficient of variation is greater than or equal to 1, it is considered that the steam distribution in the steam-liquid separator is too uneven, and the velocity correction weight of the electromagnetic wave is set equal to 1.

[0049] The calculation process of the coefficient of variation is a well-known technique, and the specific calculation steps will not be repeated here.

[0050] (2) Further, based on the velocity correction weight of the electromagnetic wave and the average distribution of the electromagnetic average velocity of all positioning echo signals, the corrected velocity of the electromagnetic wave is determined, specifically: Correction speed of electromagnetic waves The expression is: ; In the formula, It represents the mean value of the electromagnetic average velocity of all positioning echo signals; Represents the speed correction weight of electromagnetic waves; Represents the velocity correction term of electromagnetic waves.

[0051] The velocity correction term is used to characterize the velocity change of electromagnetic waves in the waveguide rod caused by uneven steam distribution, so as to eliminate the measurement error caused by the traditional liquid level measurement method and obtain the corrected velocity of the electromagnetic waves.

[0052] Preferably, the schematic diagram of the electromagnetic wave correction speed extraction process provided in this embodiment is as follows: Figure 4 shown.

[0053] (3) Further, based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid surface is determined, specifically: The distance between the positioning point corresponding to the last positioning echo and the steam liquid level The expression is: ; In the formula, Indicates the length of the liquid surface echo signal; F indicates the preset sampling frequency.

[0054] (4) Further, based on the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid liquid level, combined with the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between adjacent positioning points, the liquid level of the steam gas-liquid separator at the current moment is determined, specifically: The liquid level of the steam gas-liquid separator at the current moment The expression is: ; In the formula, It represents the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator; H represents the number of all positioning points on the waveguide rod; d represents the interval between adjacent positioning points.

[0055] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0056] Based on the same inventive concept as the above method, an embodiment of the present application also provides a steam gas-liquid separator, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the real-time liquid level monitoring method of a steam gas-liquid separator described in any one of the above items are implemented.

[0057] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0058] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Modifications to the technical solutions recorded in the aforementioned embodiments, or equivalent replacement of some of the technical features therein, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for real-time monitoring of liquid level in a steam gas-liquid separator, characterized in that: The method comprises the following steps: The guided wave radar level meter sends electromagnetic waves to the waveguide rod in the steam gas-liquid separator, and obtains the echo signal at the current moment in the guided wave radar level meter, wherein there are multiple positioning points distributed at equal intervals on the waveguide rod; Obtaining the liquid surface echo moment and all positioning echo moments in the echo signal based on the extreme value distribution in the echo signal; dividing the echo signal into a liquid surface echo signal and a plurality of positioning echo signals based on the liquid surface echo moment and all positioning echo moments; Based on the length of each positioning echo signal and the preset sampling frequency, combined with the interval between adjacent positioning points, the electromagnetic average speed of each positioning echo signal is determined; based on the similarity between each positioning echo signal and the liquid surface echo signal, the speed distribution weight of each positioning echo signal is determined, and combined with the electromagnetic average speed, the speed correction term of the electromagnetic wave is determined; The echo signal between the first positioning echo moment and the liquid surface echo moment is recorded as an electromagnetic echo signal, and the corrected speed of the electromagnetic wave is determined based on the discrete degree of all elements in the electromagnetic echo signal and the average distribution of the electromagnetic average speed of all positioning echo signals; Based on the length of the liquid surface echo signal, the correction speed and the sampling frequency, the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid liquid surface is determined, and combined with the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator and the interval between adjacent positioning points, the liquid level of the steam gas-liquid separator at the current moment is determined.

2. A method for real-time monitoring of liquid level of a steam gas-liquid separator according to claim 1, characterized in that: The step of obtaining the liquid surface echo moment and all positioning echo moments in the echo signal includes: The echo signal is used as the input of the extreme value detection algorithm, and all the maximum values ​​in the echo signal are output; The first maximum value greater than the preset threshold is recorded as the positioning echo intensity, and the upper limit of interval D is set to the product of the first preset value and the positioning echo intensity, and the lower limit is set to the product of the second preset value and the positioning echo intensity; If the maximum value is in interval D, the time corresponding to the maximum value in the echo signal is recorded as the positioning echo time, and the time corresponding to the maximum value after the last positioning echo time in the echo signal is recorded as the liquid surface echo time, where the first preset value is greater than the second preset value.

3. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 1, characterized in that: The step of dividing the echo signal into a liquid surface echo signal and a plurality of positioning echo signals comprises: The echo signals between the moment when the guided wave radar level meter starts to receive the echo signal and the moment of the first positioning echo, as well as the echo signals between two adjacent positioning echo moments, are all recorded as positioning echo signals; the echo signal between the moment of the last positioning echo and the moment of the liquid surface echo is recorded as the liquid surface echo signal.

4. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 1, characterized in that: The electromagnetic average speed of each positioning echo signal is the product of the length of each positioning echo signal, the preset sampling frequency and the interval between adjacent positioning points.

5. The method for real-time monitoring of liquid level of a steam gas-liquid separator according to claim 1, characterized in that: The velocity distribution weight of each positioning echo signal is a normalized value of the similarity between each positioning echo signal and the liquid surface echo signal.

6. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 1, characterized in that: The velocity correction term of the electromagnetic wave is the cumulative sum of the products of the velocity distribution weights of all positioning echo signals and the corresponding electromagnetic average velocity.

7. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 1, characterized in that: The method for determining the speed correction weight of the electromagnetic wave is: Calculate the coefficient of variation of all elements in the electromagnetic echo signal. If the coefficient of variation is less than 1, the speed correction weight of the electromagnetic wave is equal to the coefficient of variation. Otherwise, the speed correction weight of the electromagnetic wave is equal to 1. Correction speed of electromagnetic waves The expression is: ; In the formula, It represents the mean value of the electromagnetic average velocity of all positioning echo signals; Represents the speed correction weight of electromagnetic waves; Represents the velocity correction term of electromagnetic waves.

8. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 7, characterized in that: The expression of the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid level is: ; In the formula, Indicates the distance between the positioning point corresponding to the last positioning echo moment and the steam gas-liquid level; Indicates the length of the liquid surface echo signal; F indicates the preset sampling frequency.

9. A method for real-time monitoring of liquid level of a steam gas-liquid separator as claimed in claim 8, characterized in that: The expression of the liquid level height of the steam gas-liquid separator at the current moment is: ; In the formula, Indicates the liquid level of the steam gas-liquid separator at the current moment; It represents the distance from the electromagnetic wave emission position to the bottom of the steam gas-liquid separator; H represents the number of all positioning points on the waveguide rod; d represents the interval between adjacent positioning points.

10. A steam gas-liquid separator, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of a method for real-time monitoring of liquid level of a steam-gas-liquid separator as described in any one of claims 1-9 are implemented.

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