CN114912291A - Newly-added monitoring point arrangement method and device serving water supply network hydraulic model checking - Google Patents

Abstract

The invention discloses a method for arranging newly added monitoring points serving for water supply pipe network hydraulic model checking, which comprises the following steps: step 1, calculating and obtaining a pressure sensitivity matrix and a measurement node set of each node of the water supply network under a standard working condition of the water supply network hydraulic model; step 2, constructing a target function for calculating the monitoring effect distance between the node to be arranged and the existing monitoring point, and taking the node corresponding to the minimum solution of the target function as a newly added monitoring point; and 3, after adding the newly added monitoring points into the existing monitoring points, repeating the process in the step 2 until the arrangement state of the newly added monitoring points meets the termination condition. The invention also provides a newly added monitoring point arrangement device based on the method. According to the method provided by the invention, the measurement node set is introduced, so that the monitoring points of the scheme are finally arranged, the monitoring capability of the original monitoring points is considered, the defects of the original monitoring points are overcome, and the checking precision of the whole water supply network is improved.

Description

Layout method and device for newly added monitoring points for hydraulic model checking of water supply network

technical field

The invention belongs to the technical field of urban water supply pipe network layout, and in particular relates to a new monitoring point layout method and device for checking the hydraulic model of the water supply pipe network.

Background technique

In recent years, intelligent management of urban water supply network has become a major trend. In order to better understand the current operating status of the pipeline network, the real-time hydraulic model of the water supply pipeline network is more and more widely used in practice. Establishing a high-precision and high-efficiency real-time hydraulic model of the pipe network and using it effectively can effectively ensure the safety of urban water supply. In order to improve the accuracy of the hydraulic model of the water supply pipe network, it is necessary to check the data such as the node water demand in the model at a certain frequency based on the monitoring data of the monitoring points arranged in the pipe network. Therefore, the accuracy of the final hydraulic model is largely related to the quality of the monitoring point layout scheme.

In the actual operation of the water supply network, it is generally not necessary to dismantle or replace all the original sensors just because of the new sensors. Therefore, how to consider the original monitoring points while arranging the new monitoring points, so that the newly arranged monitoring points can complement the monitoring data of the old monitoring points, is a problem worthy of study. In view of this, the present invention proposes a method for arranging new monitoring points for hydraulic model checking of water supply network, which can effectively arrange new monitoring points in the monitoring blind area of original monitoring points and improve the checking accuracy of hydraulic model.

Patent document CN106870955B discloses a monitoring point optimization method for inversion of water demand in water supply pipe network nodes, including: 1. Selecting a reference condition for pipe network adjustment, obtaining node pressure and pipe flow, and obtaining a pressure sensitivity matrix , create a pressure influence coefficient matrix; 2. Invert the node water demand based on the monitoring values of the existing monitoring points, and adjust the node pressure and pipeline flow to create an error matrix; 3. Multiply the pressure influence coefficient matrix with the pressure error matrix , set the node corresponding to the largest element of the product as the new pressure monitoring point, and set the pipeline corresponding to the largest element of the flow error matrix as the new flow monitoring point; 4. Terminate the iteration when the number of monitoring points reaches the upper limit, otherwise continue to calculate and increase Monitoring points. This method reduces the error of the inversion algorithm by improving the traditional pressure sensitivity matrix. However, this method still needs to perform iterative calculation during the monitoring point layout process, and the generation efficiency of the layout plan has not changed.

Patent document CN114429034A discloses a method for moving and arranging pressure monitoring points for checking the water quantity of a hydraulic model of a water supply pipe network, including: dividing the checking period according to the total number of nodes in the pipe network and the number of pressure monitoring sensors; Jacobian matrix of pressure related to node water volume; according to Jacobian matrix and improved implicit enumeration optimization method, the moving arrangement scheme of monitoring points is solved; according to the monitoring data obtained from the deployment scheme of monitoring point position in each check cycle, the water supply is checked and calculated The nodal water parameters of the hydraulic model of the pipe network have improved the calculation accuracy. This method introduces a perturbation parameter into the pressure sensitivity matrix to simplify the calculation process, but it will reduce the accuracy of the final result.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a new monitoring point arrangement method for checking the hydraulic model of the water supply network. Based on the traditional pressure sensitivity matrix, the method introduces the concept of measuring node sets. The author constructs an objective function for calculating the monitoring effect distance between the nodes to be arranged and the existing monitoring points, and uses the minimum solution of the objective function each time as the new monitoring point, so that the monitoring points of the final layout plan not only take into account the original monitoring points The monitoring capabilities of the new monitoring points allow the new monitoring points to synergize with the original monitoring points, and at the same time make up for the deficiencies of the original monitoring points, and improve the calibration accuracy of the overall water supply network and specific areas.

A method for arranging new monitoring points for checking the hydraulic model of a water supply pipe network, wherein the hydraulic model of the water supply pipe network includes the topology relationship of the water supply pipe network, the pipe information of each pipe, and the water demand of each node. Monitoring point layout methods include:

Step 1. According to a standard operating condition of the hydraulic model of the water supply pipe network, calculate and obtain the pressure sensitivity matrix of each node of the water supply pipe network and a set of measuring nodes, and the set of measuring nodes includes the sets of K adjacent nodes closest to the nodes. , the K value is set manually;

Step 2. According to the pressure sensitivity matrix and the set of measurement nodes obtained in step 1, construct an objective function for calculating the monitoring effect distance between the nodes to be arranged and the existing monitoring points, and take the node corresponding to the minimum solution of the objective function as the new target function. add monitoring points;

Step 3: After adding the newly added monitoring point to the existing monitoring point, repeat the process of step 2 until the arrangement state of the newly added monitoring point satisfies the termination condition.

Since the transformation of the traditional water supply pipe network is completed by replacing or adding new sensors, and simple removal or replacement will change the original monitoring range, there will be problems of overlapping monitoring ranges or monitoring blind spots. On the basis of the traditional pressure sensitivity matrix, the invention introduces the concept of measuring node sets, constructs an objective function about the monitoring effect distance between the nodes to be arranged and the existing monitoring points, and obtains the newly added monitoring by solving the minimum solution of the objective function. Therefore, the blind area of the monitoring range between each new monitoring point and the original monitoring point is minimized.

Specifically, the pipeline information of each pipeline includes the pipeline length, pipeline diameter and friction coefficient of each pipeline.

Preferably, the pressure sensitivity matrix in the step 1 is based on the topological relationship of the hydraulic model of the water supply network and the water demand of each node, and is obtained through analytical calculation. The matrix data obtained by this method has high precision, thereby improving the final layout area. Calibration accuracy of old and new monitoring points.

Specifically, the specific construction process of the pressure sensitivity matrix is as follows:

According to the condition that any node in the water supply network satisfies the condition that its inflow and outflow are equal, the continuity equation of the node is constructed:

q _i +∑Q _i,j =0(i,j∈N)

In the formula, qi is the node water demand of node _i , Qi _,j is the flow of the pipeline with node i as the starting node and node j as the end node, that is, the pipeline flow is negative when it flows out, and the pipeline flow is inflow. Positive value; N is the node set in the water supply network model;

Combine the continuity equations corresponding to all nodes and output as a node matrix:

AQ-q=0

表示管网拓扑关系的关联矩阵，n表示水力模型中的节点数量，p表示水力模型中的管道数量，

为管道的流量向量，

为节点的需水量向量；In the formula,

is an association matrix representing the topological relationship of the pipe network, n represents the number of nodes in the hydraulic model, p represents the number of pipes in the hydraulic model,

is the flow vector of the pipeline,

is the water demand vector of the node;

At the same time, the water head difference of the nodes at both ends of any pipe in the water supply network is equal to the head loss of the pipe, so the energy equation of the pipe is constructed:

H _{i,j =} hi -h _j

In the formula, H _i,j is the head loss of the pipeline with node i as the starting node and node j as the end node, hi and h _j are the node water heads of node i and node _j respectively;

Combine the energy equations for all pipes and output as a pipe matrix:

A ^T h+H=0

为节点的水头向量，

为管道的水头损失向量；In the formula, A ^T is the transpose of the correlation matrix,

is the head vector of the node,

is the head loss vector of the pipeline;

According to the change rule of the node water demand in the water supply network, the node matrix and the pipeline matrix are modified:

Node change matrix: A(Q+ΔQ)-(q+Δq)=0

Pipeline variation matrix: A ^T (h+Δh)+(H+ΔH)=0

为管道流量的变化向量，

为节点需水量的变化向量，

为节点水头的变化向量，

为管道水头损失的变化向量；In the formula,

is the change vector of pipeline flow,

is the change vector of node water demand,

is the change vector of the node head,

is the change vector of pipe head loss;

According to the matrix and variation matrix obtained above, the head loss of the pipelines in the pipe network is calculated by the Hezen-William formula, and the differential of the pipe flow Q _s is obtained for the head loss H _f of a single pipe:

where H _f is the head loss of a pipe, Q _s is the flow rate of the pipe, L is the length of the pipe, C is the friction coefficient of the pipe, and D is the diameter of the pipe;

Then the equation that includes all pipe head losses is as follows:

ΔH=B ^-1 ΔQ

In the formula, Q _d is the pipeline flow of pipeline d, H _d is the head loss of pipeline d, and p is the total number of pipelines in the hydraulic model;

Combine and integrate the above formulas to obtain the pressure sensitivity matrix:

Specifically, the set of measurement nodes in the step 2, the specific expression is as follows:

In the formula, J _i is the set of measuring nodes of node i, N is the set of all nodes of the water supply network, Dist _i,a and Dist _i,b represent the hydraulic distance from node i to node a and node b respectively, Junc _j represents the water supply Node j in the pipe network, that is, satisfying Junc ₁ , Junc ₂ ... Junc _K are the K nodes closest to node i, and i and j represent the numbers of the nodes.

Specifically, the specific construction process of the measurement node set is as follows:

The distance matrix dist of the initialized node is as follows:

Traverse all relay nodes to update the shortest distance between all nodes, that is, if the distance between two nodes can be reduced through relay nodes, then the distance between the two nodes is updated to a new value. When the node is k, its expression can be rewritten as:

dist _i,j = min(dist _i,j ,dist _i,k +dist _k,j )

Finally, find the K nodes that are closest to each node, and these nodes constitute the node's measurement node set.

Specifically, the hydraulic distance is the shortest distance between two nodes along the pipe section, which is calculated and obtained by the Floyd algorithm based on the topological relationship of the water supply pipe network and the pipe section data.

Specifically, the objective function in the step 2, the specific expression is as follows:

In the formula, g represents the node where the monitoring point is to be arranged, G _i represents the existing monitoring point set, and MED _g,i is the monitoring effect distance of the monitoring point i relative to the node g.

Specifically, the expression of the monitoring effect distance is as follows:

In the formula, J _i ∪ J _j is the union of node i and node j to measure the node set, and S _{i, Junc} represents the sensitivity of node i to the target node Junc. S _{j, Junc} represents the sensitivity of node j to the target node Junc.

Preferably, the termination conditions include:

1. When the number of monitoring points to be arranged reaches the preset value;

2. When the monitoring effect distance of the monitoring points to be arranged reaches the threshold;

If any of the above conditions are met, the operation is terminated.

The present invention also provides a device for arranging new monitoring points, comprising a computer memory, a computer processor, and a computer program stored in the computer memory and executable on the computer processor, wherein the computer memory adopts the above-mentioned method. A method for arranging newly added monitoring points for checking the hydraulic model of the water supply pipe network; the calculator processor implements the following steps when executing the computer program: selecting a standard operating condition of the hydraulic model of the water supply pipe network, inputting a new The total number of monitoring points, after analysis and calculation, output the layout plan of new monitoring points.

Compared with the prior art, the beneficial effects of the present invention:

By reducing the dimensionality of the sensitivity vector when comparing the monitoring capabilities of nodes, focusing on the nodes that can best reflect the monitoring effect, the interference of a large number of nodes with long distances and low sensitivity is removed, and the different monitoring effects and differences between nodes can be more accurately reflected. The scope of the monitoring points can be taken into account in the final arrangement of monitoring points, so that the newly arranged monitoring points can cooperate with the original sensor system to make up for the shortcomings of the original system and improve the calibration accuracy of the overall pipeline network and specific areas.

Description of drawings

1 is a schematic flowchart of a method for arranging a new monitoring point provided by the present invention for checking the hydraulic model of a water supply pipe network;

FIG. 2 is a schematic diagram of the topological relationship of the water supply pipe network and the position of the pressure monitoring point provided by the present embodiment;

FIG. 3 is a schematic diagram of the layout of the output of the newly added monitoring point layout device provided in this embodiment;

FIG. 4 is a comparison diagram of the mean absolute error of nodal pressure provided in this embodiment;

FIG. 5 is a graph of the cumulative probability density distribution of the pressure absolute error provided in this embodiment.

Detailed ways

As shown in Figure 1, a method for arranging new monitoring points for checking the hydraulic model of a water supply network includes:

Step 1. According to a standard working condition of the hydraulic model of the water supply pipe network, calculate and obtain the pressure sensitivity matrix and measurement node set of each node of the water supply pipe network;

As shown in Figure 2, according to the topological relationship of the water supply network and the location of pressure monitoring points, a pressure sensitivity matrix is constructed:

In this water supply pipe network model, there are a total of 3 water plants, 4242 nodes (ie n=4242), 4841 pipes (ie p=4841), the total length of the pipe section is 1576.98 kilometers, and there are 48 pressure monitoring points, Among them, the correlation matrix B of the topological relationship of the pipe network is as follows:

The matrix inversion algorithm is used to solve the correlation matrix B, and the pressure sensitivity matrix S of the node is obtained:

Use the Floyd algorithm to calculate the hydraulic distance between the nodes in the pipe network, and construct a set of measurement nodes:

According to the start node, end node and length data of the pipeline in the model, the dist matrix is initialized, and then the relay nodes are enumerated to continue to update the dist matrix. An example of the partial values of the hydraulic distance dist matrix calculated using the Floyd algorithm is as follows:

Since the index number of the node in the water supply network model has little correlation with its location, even nodes with similar index numbers may still have a large hydraulic distance. Sort each column of the hydraulic distance matrix dist from small to large, and then intercept the first K rows (K=20 in this embodiment), then the set of measuring nodes of each node can be obtained, and the set of measuring nodes of some nodes is given here:

Each column in the table is the set of measuring nodes of each node. Since the hydraulic distance of a node to itself is the minimum value of 0, the set of measuring nodes of a node will always include the node itself.

Step 2. According to the pressure sensitivity matrix and measurement node set obtained in Step 1, construct an objective function for calculating the monitoring effect distance between the nodes to be arranged and the existing monitoring points, and use the node corresponding to the minimum solution of the objective function as the newly added monitoring. point:

According to the sensitivity matrix S and the measurement node set of the nodes obtained by the above calculation, the monitoring capability difference value MED between the nodes in the pipeline network is calculated. Some examples of the values are as follows:

Step 3: After adding the newly added monitoring point to the existing monitoring point, repeat the process of step 2 until the layout state of the newly added monitoring point satisfies the termination condition, wherein the termination condition includes:

1. When the number of monitoring points to be arranged reaches the preset value;

2. When the monitoring effect distance of the monitoring points to be arranged reaches the threshold;

If any of the above conditions are met, the operation is terminated.

This example also provides a device for arranging newly added monitoring points, including a computer memory, a computer processor, and a computer program stored in the computer memory and executable on the computer processor, where the above-mentioned services are used in the computer memory Layout method of new monitoring points for checking hydraulic model of water supply network;

The calculator processor implements the following steps when executing the computer program: selecting a standard operating condition of the hydraulic model of the water supply pipe network, inputting the total number of newly added monitoring points, and outputting the layout plan of the newly added monitoring points after analysis and calculation.

As shown in Figure 3, it is the final layout plan, and the termination condition this time is that the number of new monitoring points is 10.

According to the reasonable distribution of the total water consumption of the pipe network, the simulated node water demand at a certain time is generated. Through the adjustment calculation, the pressure value of the node where the sensor is located in the pipeline network is obtained, and a noise subject to the mean value of 0 and the standard deviation of 1m is added as the monitoring error, and the simulated monitoring value of all monitoring points is generated. The hydraulic model is then checked using the simulated monitoring values. After checking the hydraulic model, get the check pressure value of each node in the pipe network, compare it with the real pressure value of the simulated data, get the absolute error of the checked pressure, and make statistics to measure the new layout plan The degree to which the calibration accuracy is improved.

As shown in Figure 4, the comparison chart of the mean absolute error of the nodal pressure, including the original monitoring point, the random layout scheme of the system and the layout scheme generated by this method:

The method for arranging new monitoring points proposed by the present invention significantly improves the calibration accuracy of the original model, so that the average absolute error of nodes is reduced from 1.09m to 0.91m. When there are many monitoring points, even if 10 monitoring points are added, the improvement of calibration accuracy is very limited.

As shown in Figure 5, in order to draw the cumulative probability density distribution of the pressure absolute error, the distribution of the node pressure absolute error can be better observed:

The method for arranging the newly added monitoring points proposed by the present invention significantly improves the checking accuracy of the hydraulic model of the pipe network. The absolute pressure error of 80% nodes is less than 1.50m, the absolute pressure error of 90% nodes is less than 1.83m, and 95% The absolute pressure error of the node is less than 2.00m. The performance of the optimized layout scheme is obviously better than that of the random layout scheme, not only the maximum pressure absolute error is reduced from 2.68m to 2.43m, but also the pressure absolute error at each quantile point is reduced to a certain extent.

This is because the method proposed in the present invention can measure the monitoring capability of the existing monitoring points, and arranges new sensors in the areas that the monitoring points did not pay attention to before, so that the optimization effect is obvious for those nodes whose original calibration error is very large.

To sum up, the method for arranging new monitoring points provided by the present invention can take into account the monitoring capabilities of existing sensors, reduce the blind area of monitoring, and improve the accuracy of verification, and has practical value.

Claims (9)

1. A newly-added monitoring point arrangement method for service check of a water supply network hydraulic model, wherein the water supply network hydraulic model comprises a topological relation of a water supply network, pipeline information of each pipeline and water demand of each node, and the newly-added monitoring point arrangement method is characterized by comprising the following steps of:

step 1, calculating and obtaining a pressure sensitivity matrix and a measurement node set of each node of the water supply network under a standard working condition of the water supply network hydraulic model, wherein the measurement node set comprises K adjacent node sets nearest to the node, and the K value is set manually;

step 2, according to the pressure sensitivity matrix and the measurement node set obtained in the step 1, constructing a target function for calculating the monitoring effect distance between the node to be arranged and the existing monitoring point, and taking the node corresponding to the minimum solution of the target function as a newly added monitoring point;

and 3, after adding the newly added monitoring points into the existing monitoring points, repeating the process in the step 2 until the arrangement state of the newly added monitoring points meets the termination condition.

2. The method as claimed in claim 1, wherein the pipeline information of each pipeline includes the length of each pipeline, the diameter of each pipeline, and the friction coefficient.

3. The method as claimed in claim 1, wherein the pressure sensitivity matrix in step 1 is calculated by an analytical method based on the topological relation of the water supply network hydraulic model and the water demand of each node.

4. The method as claimed in claim 1, wherein the set of measurement nodes in step 2 is represented by the following formula:

in the formula, J _i Is a set of measurement nodes of the node i, N is a set of all nodes of the water supply network, Dist _i,a And Dist _i,b Respectively representing the hydraulic distances from node i to nodes a and b, Junc _j Indicating a node j in the water supply network, i.e. meeting Junc ₁ ，Junc ₂ …Junc _K Is the K nodes closest to node i, i and j representing the node numbers.

5. The method as claimed in claim 4, wherein the hydraulic distance is the shortest distance between two nodes along the pipeline, and is calculated by Floyd algorithm based on the topological relation of the hydraulic model of the water supply network and the pipeline data of each pipeline.

6. The method as claimed in claim 1, wherein the objective function in step 2 is expressed as follows:

wherein G denotes a node at which a monitoring point is to be arranged, G _i Indicating a set of existing watch points, MED _g,i The monitoring effect distance of the monitoring point i relative to the node g is obtained.

7. The method as claimed in claim 6, wherein the distance between monitoring effects is expressed as follows:

in the formula, J _i ∪J _j Measuring the union of node sets for node i and node j, S _i,Junc And representing the sensitivity of the node i node to the target node Junc. S _j,Junc Representing the sensitivity of node j to the target node Junc.

8. The method of claim 1, wherein the termination condition comprises:

1. when the number of the arranged monitoring points reaches a preset value;

2. when the monitoring effect distance of the monitoring points to be arranged reaches a threshold value;

any one of the above conditions is satisfied, i.e., the operation is terminated.

9. A new monitoring point placement device comprising a computer memory, a computer processor and a computer program stored in said computer memory and executable on said computer processor, wherein said computer memory is adapted to perform the new monitoring point placement method of any of claims 1-8 for use in water supply network hydraulic model verification; the computer program when executed by the computer processor implements the steps of: and selecting a standard working condition of a water supply network hydraulic model, inputting the total number of the newly added monitoring points, and outputting an arrangement scheme of the newly added monitoring points through analysis and calculation.

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