Tailing conveying pipeline dynamic alarm method based on pressure signals
Technical Field
The invention belongs to the technical field of monitoring of states of tailing conveying pipelines, and particularly relates to a dynamic alarming method for a tailing conveying pipeline based on pressure signals.
Background
In the tailing conveying process, the tailings of the separation products in the ore dressing need to be conveyed to a tailing dam for storage, so that firstly, pollution is prevented, and secondly, secondary development and utilization are waited. The tailings are powered by a diaphragm pump and are conveyed to a tailing dam through a tailing conveying pipeline.
In the actual production process, problems of pipeline blockage, pipeline leakage and the like can occur, and if the problems are found out not timely, serious consequences such as pipeline crack, large-range tailing leakage and the like can be caused. The pipeline blockage and pipeline leakage can cause the change of pipeline pressure at the outlet of the diaphragm pump, and the pressure sensor is generally arranged at the outlet of the diaphragm pump, so that pressure data can be obtained in real time. Therefore, the pressure value of the pipeline at the outlet of the diaphragm pump is monitored in real time, so that the state of the tailing conveying pipeline can be monitored to judge whether the tailing conveying pipeline breaks down or not. However, in daily production operations, the diaphragm pump needs to be adjusted according to actual production requirements, and the pressure value of the pipeline at the outlet also changes under normal conditions. According to the traditional alarm method, when the fixed threshold range is set to be too large, the situation that an alarm is not given out due to a problem is caused; when the fixed threshold range is set too small, a no problem false alarm condition will result.
At present, no automatic and effective alarm method exists for the faults of the tailing conveying pipeline, and whether the faults occur is judged only through the experience of workers on site.
Disclosure of Invention
The invention aims to solve the problem that a set of automatic and effective alarm system aiming at the faults of a tailing pipeline does not exist in a tailing pipeline conveying field, and provides a tailing pipeline dynamic alarm method based on pressure signals.
The purpose of the invention is realized by the following technical scheme:
the invention discloses a pressure signal-based dynamic alarm method for a tailing conveying pipeline, which is characterized by comprising the following steps of:
step 1: establishing a pressure mechanism model at an outlet of the diaphragm pump, and analyzing a change rule;
step 2: pressure data at the outlet of the diaphragm pump is collected through a pressure sensor, meanwhile, set value data of the diaphragm pump are collected, a database is established, and the pressure data and the set value data are simultaneously collected in time so as to avoid influence on the setting of an alarm threshold value;
and step 3: fitting a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump by using a least square method;
and 4, step 4: establishing a relational expression of a diaphragm pump set value and an alarm threshold value according to the fitting relational expression in the step 3 and formulating an alarm rule;
and 5: and comparing the pressure value acquired in real time with an alarm threshold value, and determining whether to alarm or not according to an alarm rule.
In the step 1, a pressure mechanism model at the outlet of the diaphragm pump is established, and a change rule is analyzed, and the method specifically comprises the following steps:
step 1.1: establishing a diaphragm pump mechanism model;
Q=Q1+Q2+Q3+…+Qn
p=α·Q
step 1.2: and (4) determining the pressure change rule of the outlet pipeline according to the mechanism model in the step (1).
In the step 2, pressure data at the outlet pressure of the diaphragm pump is collected through the pressure sensor, meanwhile, data of the set value of the diaphragm pump is collected, and a database is established, wherein the method specifically comprises the following steps:
step 2.1: under the condition of the same diaphragm pump set value, acquiring data of the change of the pressure of a pump outlet pipeline of the diaphragm pump along with time, and extracting the maximum value and the minimum value in each period;
step 2.2: and (4) adjusting the set value of the diaphragm pump, repeating the step 2.1, and establishing 2 databases of the maximum value of the set value of the diaphragm pump-outlet pressure of each period and the minimum value of the set value of the diaphragm pump-outlet pressure of each period.
In the step 3, a least square method is used for fitting a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump, and the specific steps are as follows:
step 3.1: selecting a first-order, second-order, third-order and fourth-order polynomial function to fit a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump;
step 3.2: and (4) selecting the most appropriate fitting function according to the fitting result in the step 3.1, and storing the function relation.
In the step 4, according to the fitting relation in the step 3, a relation between a set value of the diaphragm pump and an alarm threshold is established, and an alarm rule is formulated, and the specific steps are as follows:
step 4.1: establishing an alarm threshold value relational expression according to the functional relational expression fitted in the step 3 and the data collected in the step 1;
step 4.2: and (4) formulating an alarm rule according to the running condition of the actual diaphragm pump.
The invention has the advantages that:
compared with the prior art, the tailings conveying pipeline dynamic alarm method based on the pressure signal has the following advantages that: the pressure change rule of the diaphragm pump is known by establishing a mechanism model of the diaphragm pump, an alarm threshold dynamic calculation formula is established by a data fitting method, and an alarm rule is established according to the actual situation. The monitoring and alarming function of the tailing conveying system is realized, and the problems of no alarm and no false alarm are effectively avoided.
Drawings
Fig. 1 is a flow chart of a dynamic alarm method for a tailing conveying pipeline of the invention.
FIG. 2 is a plot of the fitted diaphragm pump set point as a function of the upper alarm threshold pressure at the outlet in an example of the invention.
FIG. 3 is a plot of the fitted diaphragm pump set point as a function of the lower alarm threshold pressure at the outlet in an example of the invention.
FIG. 4 is a graph of pressure data and alarm threshold values collected in real time in an example of the invention.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
As shown in fig. 1-4, the method for dynamically alarming the tailings conveying pipeline based on the pressure signal is characterized by comprising the following steps:
step 1: establishing a pressure mechanism model at an outlet of the diaphragm pump, and analyzing a change rule;
step 2: pressure data at the outlet of the diaphragm pump is collected through a pressure sensor, meanwhile, set value data of the diaphragm pump are collected, a database is established, and the pressure data and the set value data are simultaneously collected in time so as to avoid influence on the setting of an alarm threshold value;
and step 3: fitting a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump by using a least square method;
and 4, step 4: establishing a relational expression of a diaphragm pump set value and an alarm threshold value according to the fitting relational expression in the step 3 and formulating an alarm rule;
and 5: and comparing the pressure value acquired in real time with an alarm threshold value, and determining whether to alarm or not according to an alarm rule.
In the step 1, a pressure mechanism model at the outlet of the diaphragm pump is established, and a change rule is analyzed, and the method specifically comprises the following steps:
step 1.1: establishing a diaphragm pump mechanism model:
Q=Q1+Q2+Q3+…+Qn
p=α·Q
step 1.2: and (4) determining the pressure change rule of the outlet pipeline according to the mechanism model in the step (1).
In the step 2, pressure data at the outlet pressure of the diaphragm pump is collected through the pressure sensor, meanwhile, data of the set value of the diaphragm pump is collected, and a database is established, wherein the method specifically comprises the following steps:
step 2.1: under the condition of the same diaphragm pump set value, acquiring data of the change of the pressure of a pump outlet pipeline of the diaphragm pump along with time, and extracting the maximum value and the minimum value in each period;
step 2.2: and (4) adjusting the set value of the diaphragm pump, repeating the step 2.1, and establishing 2 databases of the maximum value of the set value of the diaphragm pump-outlet pressure of each period and the minimum value of the set value of the diaphragm pump-outlet pressure of each period.
In the step 3, a least square method is used for fitting a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump, and the specific steps are as follows:
step 3.1: selecting a first-order, second-order, third-order and fourth-order polynomial function to fit a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump;
step 3.2: and (4) selecting the most appropriate fitting function according to the fitting result in the step 3.1, and storing the function relation.
In the step 4, according to the fitting relation in the step 3, a relation between a set value of the diaphragm pump and an alarm threshold is established, and an alarm rule is formulated, and the specific steps are as follows:
step 4.1: establishing an alarm threshold value relational expression according to the functional relational expression fitted in the step 3 and the data collected in the step 1;
step 4.2: and (4) formulating an alarm rule according to the running condition of the actual diaphragm pump.
Example 1
The following will explain the specific implementation of the present invention in detail by taking the actual situation of a certain concentrating mill 1 as an example with reference to fig. 1.
The dynamic alarm method for the tailing conveying pipeline comprises the following steps:
step 1: establishing a pressure mechanism model at an outlet of the diaphragm pump, and analyzing a change rule;
step 1.1: the plant adopts a three-cylinder single-action diaphragm pump, and establishes a diaphragm pump mechanism model:
Q=Q1+Q2+Q3
step 1.2: determining the pressure change rule of the outlet pipeline according to the mechanism model in the step 1, which comprises the following specific steps:
step 2: pressure data at the outlet of the diaphragm pump is collected through the pressure sensor, and meanwhile data of set values of the diaphragm pump are collected to establish a database. The pressure data and the set value data are ensured to be simultaneously acquired in time so as to avoid influencing the setting of the alarm threshold value;
step 2.1: under the condition of the same diaphragm pump set value, acquiring data of the change of the pressure of a pump outlet pipeline of the diaphragm pump along with time, and extracting the maximum value and the minimum value in each period;
step 2.2: and (4) adjusting the set value of the diaphragm pump, repeating the step 2.1, and establishing 2 databases of the maximum value of the set value of the diaphragm pump-outlet pressure of each period and the minimum value of the set value of the diaphragm pump-outlet pressure of each period.
And step 3: fitting a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump by using a least square method;
step 3.1: selecting a first-order, second-order, third-order and fourth-order polynomial function to fit a relational expression between the outlet pressure of the diaphragm pump and a set value of the diaphragm pump;
step 3.2: selecting the most appropriate fitting function according to the fitting result in the step 3.1, and storing a function relation formula, wherein the relation formula is as follows:
the fitting function of the set value of the diaphragm pump and the maximum value of the pressure at the outlet is as follows:
f(x)=-0.2354x2+76.98x+1.672
the fitting function of the diaphragm pump set value and the pressure minimum value at the outlet is as follows:
f(x)=-0.233x2+76.69x+2.661
and 4, step 4: establishing a relational expression of a diaphragm pump set value and an alarm threshold value according to the fitting relational expression in the step 3 and formulating an alarm rule;
step 4.1: establishing an alarm threshold value relational expression according to the functional relational expression fitted in the step 3 and the data collected in the step 1, wherein the relational expression is as follows:
the relation between the set value of the diaphragm pump and the upper limit alarm threshold value of the pressure at the outlet is as follows:
f(x)=-0.2354x2+76.98x+20
the relation between the set value of the diaphragm pump and the lower limit alarm threshold value of the pressure at the outlet is as follows:
f(x)=-0.233x2+76.69x-20
step 4.2: according to the operation condition of the actual diaphragm pump, an alarm rule is formulated as follows:
pressure upper limit alarm rules:
the first step is as follows: judging whether the maximum value in continuous 5 working cycles of the diaphragm pump is larger than the upper pressure limit alarm threshold value or not;
the second step is that: if the judgment in the first step is negative, no alarm is given; otherwise, judging whether the membrane pump set value in the third period is larger than the set value in the first period;
the third step: if the second step is judged to be negative, no alarm is given; otherwise, a first-level upper limit alarm is sent to remind an operator of pressure rise caused by problems such as pipeline blockage.
The fourth step: and if the upper limit alarm is sent out, the first step to the third step are repeated in the next 5 periods. And if the set value is unchanged and the pressure value continuously exceeds the upper limit alarm threshold value, a secondary upper limit alarm is sent out.
And (3) a lower pressure limit alarm rule:
the first step is as follows: judging whether the minimum value in continuous 5 working cycles of the diaphragm pump is smaller than a pressure lower limit early warning value or not;
the second step is that: if the judgment in the first step is negative, no alarm is given; otherwise, judging whether the set value of the diaphragm pump in the third period is smaller than the set value in the first period;
the third step: if the second step is judged to be negative, no alarm is given; otherwise, a lower limit alarm is sent to remind an operator of pressure reduction caused by problems such as pipeline leakage and the like.
The fourth step: and if the lower limit alarm is sent out, the first step to the third step are repeated in the next 5 periods. If the set value is unchanged and the pressure value is continuously lower than the lower limit alarm threshold value, a secondary lower limit alarm is sent out.
And 5: and comparing the pressure value acquired in real time with an alarm threshold value, and determining whether to alarm or not according to an alarm rule.
The results of example 1 are shown in fig. 4, which shows the upper alarm threshold, the lower alarm threshold and the real-time data collected during a certain period of time. The time interval for collecting data in this example is 1 second, and the total time is 839 seconds. As can be seen from the figure, the alarm threshold varies with the change in the diaphragm pump setting. Meanwhile, most pressure data can be seen to be in the upper limit alarm threshold range and the lower limit alarm threshold range, when the set value of the diaphragm pump is changed, some pressure data are out of the alarm threshold range, and according to the alarm rule in the step 4, the time that the pressure value is out of the threshold range in the graph is less than 3 diaphragm pump working cycles, so that the alarm cannot be given.
Compared with the existing method, the tailings conveying pipeline dynamic alarm method based on the pressure signal has the following advantages that: the pressure change rule of the diaphragm pump is known by establishing a mechanism model of the diaphragm pump, an alarm threshold dynamic calculation formula is established by a data fitting method, and an alarm rule is established according to the actual situation. The monitoring and alarming function of the tailing conveying system is realized, and the problems of no alarm and no false alarm are effectively avoided.