Multivariable-based safety early warning method for gas pressure regulator
Technical Field
The invention relates to the technical field of gas transmission and distribution, in particular to a safety early warning method for a gas pressure regulator based on multivariable.
Background
At present, the operation management of a gas pressure regulating station is mainly realized through daily routing inspection, and whether a gas pressure regulator fails or not is judged according to the experience of a manager; however, there are many problems with this conventional, manual method of determining.
(1) There is no unified criterion for the fault state and the normal state of the gas regulator: the fault elimination by relying only on the experience of the technician can generate a plurality of uncertain factors, for example, for the same condition, some technicians consider the fault condition, and some technicians consider the fault condition, so that the potential safety hazard of the gas pressure regulator is buried.
(2) Slight abnormal conditions of the gas pressure regulator are difficult to find: in the actual operation process of the gas pressure regulator, certain damage can occur to some parts after working for a period of time, but the slight abnormal condition that appears is often difficult to discover by managers, especially for the gas pressure regulator in the looped network, the pressure, the flow and the like can complement each other, and the abnormal condition can not be judged according to a single variable. If the whole pressure regulating process deviates from the normal state for a long time, the faults of the gas pressure regulator are increasingly worsened, and more maintenance cost is increased when the aggravated abnormal condition is discovered.
(3) The waste of manpower and financial resources is serious: in order to ensure the safe operation of the gas pressure regulator, the existing method is to set up a set of strict maintenance operation flow, which requires strict execution by personnel at all levels, but the conservative operation and maintenance and management system greatly increases the production and operation cost.
Therefore, how to accurately determine whether the gas pressure regulator has a fault, find a slight abnormal condition of the gas pressure regulator in time, and reduce the operation cost of the gas pressure regulator becomes a key point for the technical problems to be urgently solved and the research of the technicians in the field.
Disclosure of Invention
In order to solve the problems that whether the gas pressure regulator fails or not, slight abnormal conditions are discovered too late, the operation cost is too high and the like in the conventional gas pressure regulator management, the invention innovatively provides a multivariable-based gas pressure regulator safety early warning method, and the monitoring, the fault early warning and the alarm of the operation condition of the gas pressure regulator are preferably realized, so that whether the gas pressure regulator fails or not is accurately judged, the slight abnormal conditions are discovered as soon as possible, the cost investment is effectively reduced, the intelligent and fine management of the gas pressure regulator is realized, and the working safety of the gas pressure regulator is greatly improved.
In order to achieve the technical purpose, the invention innovatively provides a multivariable-based gas pressure regulator safety early warning method, which comprises the following steps,
step 1, collecting an outlet pressure signal of a gas pressure regulator;
step 2, obtaining a first frequency band energy distribution rule of the outlet pressure signal in a wavelet packet energy analysis mode;
step 3, determining a gas pressure regulator with high-frequency faults or low-frequency faults by using the first frequency band energy distribution rule;
step 4, acquiring a pressure radar chart of the gas pressure regulator with the high-frequency fault or the low-frequency fault, wherein the pressure radar chart comprises an outlet pressure radar chart and/or a load pressure radar chart;
and 5, judging whether to perform fault early warning or fault alarm on the gas regulator according to the pressure radar chart.
The invention innovatively adopts a wavelet packet energy analysis mode to process the outlet pressure signal of the gas pressure regulator, thereby realizing the preliminary judgment of low-frequency faults or high-frequency faults of the gas pressure regulator, and selectively carrying out fault early warning or fault alarming according to the actual conditions of each gas pressure regulator on the basis, thereby realizing the accurate judgment of the faulted gas pressure regulator, finding the slight abnormality of the gas pressure regulator as early as possible, and further greatly reducing the maintenance cost of the gas pressure regulator and the integral production and operation cost.
Further, in order to realize early warning or alarm on specific high-frequency fault types, in step 3 of the invention, for the gas pressure regulator with the high-frequency fault, a second frequency band energy distribution rule of a load pressure signal is obtained in a wavelet packet energy analysis mode, and a first correlation relation between the load pressure signal and an outlet pressure signal is determined; determining a high-frequency fault type by utilizing the second frequency band energy distribution rule and the first correlation;
in step 5, for the gas pressure regulator with the high-frequency fault, the fault early warning or fault alarm information comprises the high-frequency fault type.
Further, in step 3, if the second frequency band energy distribution rule conforms to the signal frequency band energy distribution change caused by surge and the first correlation coefficient calculated through the first correlation relation is greater than a first preset coefficient, the high-frequency fault type is director surge; otherwise, the high frequency fault type is main valve surge.
Further, in order to realize early warning or alarm on specific low-frequency fault types, in step 3 of the invention, for the gas pressure regulator with low-frequency faults, a first voltage stabilization index of the gas pressure regulator at a gas consumption peak time period and a second voltage stabilization index of the gas pressure regulator at a gas consumption low-peak time period are respectively calculated; if the second stable voltage index is larger than the first stable voltage index, the low-frequency fault type is that the outlet pressure is high; if the first voltage stabilization index is larger than the second voltage stabilization index, the low-frequency fault type is low outlet pressure;
in step 5, for the gas pressure regulator with the low-frequency fault, fault early warning or fault warning information of the gas pressure regulator comprises a low-frequency fault type.
Further, in step 3, in order to avoid the misjudgment of the low-frequency fault, the invention determines a second correlation relationship between the outlet pressure signal and the flow signal of the gas pressure regulator with the low-frequency fault, and if the second correlation number calculated by the second correlation relationship is greater than a second preset coefficient, the current gas pressure regulator operates normally and cancels the judgment of the low-frequency fault.
Further, in order to realize safety early warning more specifically, in the step 1, the operation data of all the gas pressure regulators in one day is read, the branch where the gas pressure regulator with the average load pressure greater than the average outlet pressure is located is determined as a main operation pressure regulating branch, and the outlet pressure signal of the gas pressure regulator on the main operation pressure regulating branch is acquired.
Further, in order to improve the accuracy and reliability of the calculation of the voltage stabilization index, in step 3 of the invention, the first and/or second voltage stabilization index is calculated in the following way:
where K denotes the voltage stabilization index to be calculated, P i Indicating the actual value of the outlet pressure, P, of the gas pressure regulator s The set pressure value of the gas pressure regulator is represented, and n represents the number of outlet pressure collection points.
Further, in order to improve the accuracy and reliability of the correlation calculation, in step 3 of the present invention, the first and/or second correlation is determined as follows:
wherein ρ XY Denotes a correlation coefficient, cov (X, Y) denotes a covariance between two random variables X and Y, and D (X), D (Y) denote variances of the two random variables X and Y, respectively.
Further, in step 2, performing 3-layer wavelet packet decomposition on the outlet pressure signal, so that 8 sequentially arranged frequency band energies are in the obtained first frequency band energy distribution rule;
in step 3, screening out a gas pressure regulator with the frequency band energy mean value higher than a preset safety value, wherein: the gas pressure regulator with the frequency band energy increasing trend has high-frequency faults, and the gas pressure regulator with the 1 st frequency band energy higher than other frequency band energy has low-frequency faults.
The invention has the beneficial effects that: the invention realizes the monitoring of the operation condition of the gas pressure regulator and the fault early warning alarm, thereby obviously improving the safety and the reliability of the work of the gas pressure regulator, realizing the intelligent and fine management of the gas pressure regulator and effectively solving a plurality of problems in the management of the existing gas pressure regulator.
Drawings
Fig. 1 is a schematic flow chart of a multivariable-based gas pressure regulator safety early warning method.
Detailed Description
The safety precaution method of the gas pressure regulator based on multivariable of the invention is explained and explained in detail below with reference to the attached drawings.
As shown in the attached figure 1, the invention specifically discloses a multivariable-based gas pressure regulator safety early warning method which is used for safety early warning of a gas pressure regulating station and specifically comprises the following steps.
Step 1, collecting an outlet pressure signal of a gas pressure regulator; specifically, the present embodiment performs the data preprocessing operation: reading the operation data of all the gas pressure regulators in one day, wherein the operation data is read once per minute, so that 1440 groups are in total in one day, determining a branch where the gas pressure regulator with the average load pressure being greater than the average outlet pressure is located as a main operation pressure regulating branch, and collecting outlet pressure signals of the gas pressure regulators on the main operation pressure regulating branch; and if the pressure difference between the average load pressure and the average outlet pressure does not change along with the flow or the average outlet pressure is greater than the average load pressure, directly judging that the gas pressure regulator is in a closed state. In this embodiment, since the judgment principle uses data of one day as the minimum unit, only branches that are opened in a certain time period in one day are ignored, and only branches that are opened all day are analyzed.
The present embodiment determines the high-frequency fault and the low-frequency fault by a wavelet packet energy method, which is described below.
And 2, decomposing the high-frequency signal and the low-frequency signal without leakage in a wavelet packet energy analysis mode to obtain a first frequency band energy distribution rule of the outlet pressure signal. In this embodiment, a wavelet packet basis function db6 may be adopted to perform 3-layer wavelet packet decomposition on the outlet pressure signal, so that the obtained first frequency band energy distribution rule has 8 sequentially arranged frequency band energies, and the gas pressure regulator with a good operation state has a small integral wavelet packet frequency band energy; the latter items of the wavelet packet frequency band energy of the pressure regulator with the surge fault tendency are higher; while a regulator with a higher or lower outlet pressure has a relatively higher first term for the wavelet band energy.
Step 3, determining a gas pressure regulator with a high-frequency fault or a low-frequency fault by using a first frequency band energy distribution rule; in this embodiment, select the gas pressure regulator that frequency band energy mean value is higher than predetermineeing the safe value, wherein: among the screened gas pressure regulators, the gas pressure regulator with the frequency band energy increasing trend has high-frequency faults, and the gas pressure regulator with the 1 st frequency band energy higher than the energy of other frequency bands has low-frequency faults. For the preset safety value, the safety value can be reasonably set according to the specific condition of the gas pressure regulating station.
In particular, for gas regulators that fail at high frequencies, there may be two reasons: on one hand, the damage of an internal cavity or a leather membrane of a main valve of the pressure regulator causes extreme instability of internal airflow organization to cause surging of outlet pressure; on the other hand, the surge of the load pressure caused by the over-sensitivity of the commander spring further causes the surging phenomenon of the outlet pressure. The invention innovatively obtains a second frequency band energy distribution rule of a load pressure signal in a wavelet packet energy analysis mode, and determines a first correlation relation between the load pressure signal and an outlet pressure signal; determining a high-frequency fault type by using a second frequency band energy distribution rule and the first correlation; in this embodiment, if the second frequency band energy distribution rule conforms to the signal frequency band energy distribution change caused by surge and the first correlation coefficient calculated through the first correlation relationship is greater than the first preset coefficient, the high-frequency fault type is director surge; otherwise, the high frequency fault type is main valve surge. In this embodiment, the first predetermined coefficient is 0.5.
Specifically, for the gas pressure regulator with the low-frequency fault, a second correlation relation between an outlet pressure signal and a flow signal of the gas pressure regulator is determined, and if the second correlation number calculated through the second correlation relation is larger than a second preset coefficient, it is indicated that the pressure fluctuation of the outlet of the gas pressure regulator is caused by large fluctuation of the flow, namely the current gas pressure regulator operates normally, and the judgment that the low-frequency fault exists in the current gas pressure regulator is cancelled. If the second correlation number calculated by the second correlation is less than or equal to a second preset coefficient, calculating a first pressure stabilization index KH of the gas pressure regulator and a second pressure stabilization index KL of the gas pressure regulator during a peak-to-gas period (7 to 10 am and 18 to 20 pm); if the second voltage stabilization index is larger than the first voltage stabilization index, the low-frequency fault type is that the outlet pressure is high; if the first voltage stabilization index is larger than the second voltage stabilization index, the low-frequency fault type is low outlet pressure; therefore, the technical scheme disclosed by the invention can realize real-time fault diagnosis and early warning alarm for the station in the fault frequent time periods such as the gas consumption low peak time period, the gas consumption high peak time period and the like, thereby ensuring the production safety and greatly saving the operation cost. In this embodiment, the second predetermined coefficient is 0.8; the first standard index range and the second standard index range can be reasonably set according to actual conditions on the basis of the technical scheme disclosed by the invention.
In this embodiment, the first and/or second stability indicator is calculated as follows: root mean square deviation of actual outlet pressure of the gas pressure regulator from the set pressure as a percentage of the set pressure.
Where K denotes the voltage stabilization index to be calculated, P i Representing the actual value of the outlet pressure (in bar) of the gas pressure regulator, P s And a set pressure value (unit is bar) of the gas pressure regulator is represented, and n represents the number of outlet pressure acquisition points.
In this embodiment, the first and/or second correlation relationship is determined as follows: the sign indicates the direction of correlation, the absolute value indicates the degree of correlation between the variables, and the larger the correlation coefficient, the higher the degree of correlation between two random variables.
Where ρ is XY Representing a correlation coefficient, cov (X, Y) representing a covariance between two random variables X and Y, and D (X), D (Y) representing a variance of the two random variables X and Y, respectively; in this embodiment, the correlation coefficient has a value range of [ -1,1 [ ]]Where | ρ | XY |>, 0.9 represents significant correlation; | ρ XY | ≧ 0.8 indicates high correlation; rho is not less than 0.5 XY I < 0.8 indicates moderate correlation; l ρ XY An | of < 0.5 indicates a general correlation.
And 4, acquiring a pressure radar map of the gas pressure regulator with the high-frequency fault or the low-frequency fault, wherein the pressure radar map comprises an outlet pressure radar map and/or a load pressure radar map.
And 5, judging whether to perform fault early warning or fault alarm on the gas regulator according to the pressure radar map. Specifically, whether further maintenance is needed or not and whether alarming or early warning is needed or not can be confirmed in a mode of automatically judging or manually judging the pressure radar map by a technician, and for the gas pressure regulator with the high-frequency fault, the fault early warning or fault warning information comprises a high-frequency fault type; for the gas pressure regulator with low-frequency faults, fault early warning or fault warning information comprises low-frequency fault types, so that fault identification and early warning of the gas pressure regulator are realized.
In specific implementation, the safety early warning method disclosed by the invention can be mainly realized by a specially designed multivariable safety early warning knowledge model of the gas pressure regulator, and the knowledge model adopts a plurality of early warning indexes: band energy E i Voltage stabilization index K and correlation coefficient rho XY After data collected on site of the gas regulator is preprocessed, the preprocessed data are input into the knowledge model, and output results are used for guiding safe production operation and later-stage perfection and optimization of the gas system. In addition, the invention can also continuously optimize the knowledge model in the accumulation process of the subsequent fault cases, thereby achieving the purpose of effectively reducing the false alarm rate.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise.
In the description of the present specification, reference to the description of the terms "this embodiment," "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and simplifications made in the spirit of the present invention are intended to be included in the scope of the present invention.