A high-precision network solution method based on mass-volume flow double coupling

Abstract

The application discloses a high-precision network solving method based on mass-volume flow double coupling, relates to the technical field of mine ventilation, and adopts Kruskal algorithm to select a minimum wind resistance tree; mass air quantity of all branches is represented by the mass air quantity of a residual tree chord, and a wind pressure balance equation set is established; the mass air quantity of the residual tree chord is calculated, and a correction value of each residual tree chord mass air quantity is calculated; the mass air quantity of all branches is iteratively corrected, and when a convergence condition is reached, high-precision mass air quantity of all branches is obtained; and then high-precision volume air quantity of all branches is calculated. The application takes mass flow as a calculation reference, the calculation of the mass flow is not disturbed by air density change, the air flow dynamics in the mine ventilation network can be more accurately simulated, the volume flow solving error is significantly reduced, and the calculation precision and efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of mine ventilation technology, and in particular to a high-precision network solution method based on mass-volume flow rate dual coupling. Background Technology

[0002] Coal resources are the cornerstone of my country's energy security. With the increasing frequency and normalization of deep mining activities, improving the level of intelligent mine ventilation technology has become an urgent task. The intelligent transformation of ventilation systems is not only a core element in building intelligent mines but also crucial for ensuring safe mine production. The scientific and rational design of these systems directly affects mine safety and production efficiency. By introducing advanced intelligent technologies, dynamic monitoring and optimized management of ventilation systems can be achieved, thereby promoting efficient and sustainable mine production while ensuring safety, and providing a strong guarantee for national energy security.

[0003] Zhong Deyun et al. addressed the problems of chaotic fan management and recirculating air in traditional mine ventilation designs by employing a depth-first search (DFS) method to find the minimum independent closed loop and establishing a solution method for multi-fan, multi-stage station ventilation networks. Lei Yajun et al. addressed the issues of inaccurate measurement and constantly changing mine ventilation parameters by adopting a multi-scenario adaptive ventilation network solution method. Through improvements to the nodal pressure energy equation and clustering noise reduction algorithm, they achieved high fidelity in reproducing the operating state of the ventilation network. Qin Tao et al. addressed the problems of traditional coal mine ventilation systems lacking intelligent adjustment, regional pollution, and poor ventilation by dynamically adjusting ventilation system parameters based on a three-dimensional network model and mathematical model, combined with sensor data, thus improving the intelligent adjustment and optimization capabilities of airflow within the mine. Tan Xiaolin et al. addressed the issues of mine ventilation... To address the slow convergence and inability to converge in network solutions, a method was adopted that first checks for the existence of self-loops in the ventilation network. If no self-loops exist, the ventilation network is simplified and solved using the loop airflow method; if self-loops exist, the nodal air pressure method is used, effectively improving computational efficiency and accuracy. Xie Biao et al. addressed the lag and high error rate of traditional mine ventilation network solutions by employing tree simplification and graph theory methods, effectively improving solution speed and accuracy, and providing an efficient and accurate data processing method for intelligent mine ventilation systems. Liu Hui et al. addressed the problem that traditional ventilation network solution models cannot simultaneously handle daily ventilation and disaster simulation by using a one-to-three-dimensional coupled model, combining rapid one-dimensional calculation with accurate three-dimensional simulation, achieving adaptive solution of the entire mine ventilation network, and improving computational efficiency and accuracy. Han Xiaohui et al. addressed the slow speed and poor accuracy of mine ventilation network solutions by employing methods such as meshing, weight assignment, and dual-path methods to achieve rapid convergence and improve solution speed and accuracy.

[0004] Existing mine ventilation network airflow calculation techniques commonly employ traditional methods based on volumetric flow rate, which neglect the impact of air density variations. This has significant drawbacks. Traditional methods assume a constant air density, but environmental conditions change significantly with increasing mine depth. During iterative airflow calculations, these methods fail to adequately account for the influence of air density variations on ventilation flow rate, leading to substantial discrepancies between the calculated volumetric flow rate and the actual flow rate in mine environments with uneven air density distribution. This discrepancy not only hinders accurate airflow allocation but may also adversely affect the design and operation of the ventilation system, ultimately impacting mine safety. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems by providing a high-precision network calculation method based on mass-volume flow rate dual coupling, thus overcoming the shortcomings of existing technologies in terms of calculation errors caused by changes in air density.

[0006] The technical solution adopted in this invention is as follows:

[0007] A high-precision network solution method based on mass-volume flow rate dual coupling includes the following steps:

[0008] S1, Input the ventilation network topology diagram of the target mine, which includes several branches. Input each branch Data, calculate each node relative humidity at the location air density Calculate the volumetric airflow within each branch. Mass airflow M within the branch, branch ventilation resistance H, and frictional resistance. ;

[0009] S2, using Kruskal's algorithm to generate the minimum drag tree. ;

[0010] S3, increase the mass airflow of all branches Yu Shuxian's mass air volume This indicates that a system of wind pressure balance equations is established to solve for the mass air volume of Yu Shuxian. ;

[0011] S4, calculate the wind pressure error of the wind pressure balance equation, and obtain the correction value of the mass air volume of each coherent tree chord based on the wind pressure error;

[0012] S5, based on the correction value of the mass airflow of each coaxial tree chord, adjust the mass airflow of all branches. After iterative correction, and upon reaching the convergence condition after t iterations, the high-precision mass air volume of all branches is obtained. ;

[0013] S6 utilizes high-precision mass airflow across all branches. The high-precision volumetric air volume of all branches is calculated. .

[0014] Furthermore, in S2, the Kruskal algorithm is used to select the minimum drag tree. The method includes the following steps:

[0015] S201, Initialization Phase: For all branches According to frictional wind resistance Sort in ascending order to form an ordered branch set. = , Indicates the first One branch, Indicates the first Branches Frictional wind resistance; creating an empty set Initialize the full node set Full node set Store all nodes Initialize the disjoint-set data structure so that each node Independently forming single-element connected components, disjoint-set data structure and array that satisfies and , Represents the set of all nodes There are nodes , Represents the set of all nodes There is a unique node. ;

[0016] S202, Core Processing Stage: Algorithm Traversal Each branch For the current branch The starting node is obtained through the disjoint-set data structure operation. and end node , Indicates the current branch The starting node The root of the connected component. , Indicates the current branch End node The root of the connected component , This function represents the process of finding a node; when a node is detected... hour, If they belong to different connected components, then the corresponding branches join in Set, corresponding starting node Through disjoint-set data collection Operation merge For the corresponding connected components, update the parent and rank arrays of the disjoint-set data structure; when a connection is detected... Skip the branch. To prevent loops from forming; each successful addition of a new branch Post-detection termination conditions , Represents a set of nodes The number of nodes in express The number of branches in the set;

[0017] S203, Result Output Stage: When the algorithm meets the termination condition, record the result at this point. Minimum drag tree And output it.

[0018] Furthermore, the method for establishing the wind pressure balance equation in S3 includes the following steps:

[0019] S301, the ventilation network topology diagram belongs to the minimum wind resistance tree. Branches in This is referred to as a tree branch, and it does not belong to the minimum resistance tree in the ventilation network topology diagram. branch This is called a residual tree string. Each residual tree string corresponds to an independent loop in the ventilation network. The residual tree string airflow is extracted, and it is the airflow of its corresponding independent loop. The residual tree string airflow includes the residual tree string mass airflow. The volumetric air volume of Yu Shuxian Calculate the mass air volume of the remaining tree chord. The volumetric air volume of Yu Shuxian :

[0020] Assume the mass air volume of the remaining tree chord Let the wind density of the remaining tree string be... Let the volume of the remaining tree string be the air volume. , Then there is

[0021]

[0022] In the above formula, , Indicates the first The mass air volume of the remaining tree string Indicates the first The volume of windage of a single tree string. Indicates the first The airflow density of the remaining tree string;

[0023] S302, using Yu Shuxian's mass air volume Establishing the wind pressure balance equation includes the following steps:

[0024] The wind pressure balance equation for the independent loop is as follows:

[0025]

[0026] In the above formula, Indicates the first The branch and the first The topological relationship of an independent loop; express ; ;

[0027] Mass air volume of all branches Both are written as Yu Shuxian's mass air volume The function is used to establish a system of wind pressure balance equations, and the mass air volume of Yu Shuxian is obtained by solving the equations. :

[0028]

[0029] The above formula represents the expression by The mass air volume of the tree string The set of wind pressure balance equations. Indicates the first The system of wind pressure balance equations can be solved by finding the solution. The mass air volume of the tree string , Indicates the first branch among all branches Frictional wind resistance of each branch Indicates the first branch among all branches The airflow density of each branch, Indicates the first branch among all branches The wind pressure of the fan contained in each branch. Indicates the first branch among all branches The natural wind pressure contained in each branch. Indicates the first branch among all branches The mass air volume of each branch.

[0030] Furthermore, in S4, the wind pressure error of the wind pressure balance equation is calculated. The wind pressure balance equation is then subjected to a Taylor expansion, and the Jacobi matrix is ​​simplified using the Seidel principle. The specific steps are as follows:

[0031] Wind pressure balance equations After the second iteration, the mass air volume of Yu Shuxian was obtained. :

[0032]

[0033] In the above formula, Indicates the first During the nth iteration Mass air volume of the remaining tree chord;

[0034] The first The wind pressure balance equation during iteration is expanded using the Taylor formula:

[0035]

[0036] In the above formula, Indicates the first A wind pressure balance equation Indicates the first At the +1st iteration, the... Residual tree chord mass air volume, Indicates the first During the nth iteration Correction value for mass air volume of the remaining tree chord. , Indicates the number of nodes. Indicates the number of branches. ;

[0037] Neglecting the second-order higher-order differentials in the above equation, then the... The linear approximation is:

[0038]

[0039] Rewrite the above equation in matrix form:

[0040]

[0041] The simplified calculation is as follows:

[0042]

[0043] In the above formula, Indicates the first The wind pressure balance equation for the first The mass air volume of the tree string The partial derivatives, first derivatives, and Jacobi coefficient matrix have strict diagonal dominance. Neglecting derivatives of the same order, i.e., neglecting off-diagonal terms in the coefficient matrix, yields:

[0044]

[0045] The above formula can be written as:

[0046]

[0047] Right now:

[0048]

[0049] In the above formula, Indicates the first The wind pressure error in the wind pressure balance equation.

[0050] Furthermore, the method for obtaining the correction value of the mass air volume of each cofactory tree chord based on the wind pressure error in S4 is as follows:

[0051] Will Described as The function, derivation The specific expression:

[0052]

[0053] In the above formula, Indicates the first Quality flow of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the number of nodes. Indicates the number of branches. , ;

[0054] Combining the above equation with the wind pressure balance equation, we get:

[0055]

[0056] In the above formula, Indicates the first A wind pressure balance equation Indicates the first The branch and the first Topological relationships of individual loops, Indicates the first Frictional wind resistance of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the first The airflow density of each branch, Indicates the first The wind pressure of the fan contained in each branch. Indicates the first The natural wind pressure contained in each branch. Indicates branch Frictional wind resistance;

[0057] In the above formula right Taking the derivative, we get:

[0058]

[0059] In the above formula, Indicates the first Branches , represents a constant, therefore ,when right Differentiation is only possible when Its derivative is not zero, therefore Similarly,

[0060]

[0061] We can obtain:

[0062]

[0063] Represented as:

[0064]

[0065] In the above formula, Indicates the first During the nth iteration The mass air volume of the remaining tree string Indicates the first Branches and loops Topological relationships;

[0066] Yu Shuxian's mass air volume correction value The formula for calculation is:

[0067] .

[0068] Furthermore, the mass airflow of all branches in S5 The method for iterative correction is as follows:

[0069] No. sequence The mass air volume of each branch is :

[0070]

[0071] In the above formula, Indicates the number of nodes. Indicates the number of branches. , Indicates the first During the nth iteration Mass air volume of each branch Indicates the first Branches and loops Topological relationships, Indicates the first After the nth iteration Correction value for the mass air volume of the remaining tree chord.

[0072] Furthermore, the convergence condition in S5 is:

[0073] Iterate continuously on the quality airflow correction values ​​for each independent loop. Until the t-th iteration, the maximum independent loop mass airflow correction value is... Less than the set precision That is,

[0074]

[0075] The high-precision mass air volume of all branches can be obtained by solving the problem. = , .

[0076] Furthermore, The flow rate is 0.00001 to 0.01 kg / min.

[0077] Furthermore, the S6 employs high-precision mass airflow across all branches. Calculate the high-precision volumetric air volume of all branches The method is as follows:

[0078]

[0079]

[0080] In the above formula, , This indicates that after the t-th iteration reaches the convergence condition, the th iteration... High-precision volumetric air volume for each branch. Indicates the first After the convergence condition is met in the nth iteration, the th... Mass air volume of each branch Indicates the first The airflow density of each branch.

[0081] Furthermore, in S1 at each node Set up measurement points at the location to obtain data for each branch. The data.

[0082] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0083] 1. This invention uses mass flow rate as the calculation benchmark. Since the calculation of mass flow rate is unaffected by changes in air density and fully considers these changes, it can more accurately simulate the airflow dynamics in mine ventilation networks, significantly reducing volumetric flow rate calculation errors and improving calculation accuracy and efficiency. This enables precise and efficient maintenance and fault diagnosis of ventilation systems, helping to reduce long-term operation and maintenance costs. Based on adaptive parallel computing technology, this invention can handle multiple computational tasks simultaneously, greatly shortening the solution time. This invention is applicable to large and complex ventilation networks.

[0084] 2. This invention adopts a multi-threaded and multi-process parallel computing strategy, which can simultaneously process the flow calculation of multiple branches or nodes, shorten the solution time, and improve the computing efficiency. This invention is applicable to mines under large ventilation network conditions.

[0085] 3. By coupling the dynamic relationship between mass flow rate and volume flow rate, this invention can comprehensively capture the distribution and variation characteristics of air density in shafts and tunnels, and significantly improve the real-time performance and accuracy of the solution by leveraging a big data parallel computing architecture.

[0086] 4. The precise flow calculation method in this invention supports a more reasonable ventilation network design, ensuring the effectiveness and safety of the system, thereby significantly improving the production efficiency and safety of the mine. Attached Figure Description

[0087] Figure 1 This is a flowchart illustrating the present invention;

[0088] Figure 2 This invention generates a minimum drag tree based on Kruskal's algorithm. Flowchart;

[0089] Figure 3 This is a diagram of the ventilation network topology of the target mine in the experimental simulation. Detailed Implementation

[0090] The present invention will now be described in detail with reference to the accompanying drawings.

[0091] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0092] Example 1

[0093] A high-precision network solution method based on mass-volume flow rate dual coupling, such as Figure 1 , Figure 2 As shown, it includes the following steps:

[0094] S1, Input the ventilation network topology diagram of the target mine, which includes several branches. Input each branch The data, each branch The data includes branch number and starting node. End node Branch cross-sectional area S, dry bulb temperature wet-bulb temperature ; at each node Measuring points are set up at each point, and the dry-bulb temperature of the air at each measuring point is measured using a dry-bulb thermometer. The wet-bulb temperature of the air at each measuring point was measured using a wet-bulb thermometer. The absolute static pressure P at each measuring point is measured using a mine ventilation parameter detector used for underground measurement; at the mine entrance, a base point is set up to calibrate the mine ventilation parameter detector.

[0095] Calculate the relative humidity at each node v. air density Calculate the volumetric airflow within each branch. Mass airflow M within the branch, branch ventilation resistance H, and frictional resistance. :

[0096] Calculate each node At dry-bulb temperature, the saturated vapor pressure of water vapor saturated vapor pressure of water vapor at wet-bulb temperature :

[0097]

[0098]

[0099] In the above formula, This represents the saturated vapor pressure of water vapor at dry-bulb temperature, in kPa. Indicates dry bulb temperature; Indicates wet-bulb temperature This represents absolute static pressure, in kPa. This represents the saturated vapor pressure of water vapor at wet-bulb temperature, in kPa.

[0100] Calculate the relative humidity at node v :

[0101]

[0102] In the above formula, Indicates relative humidity of the air. This represents the saturated vapor pressure of water vapor at dry bulb temperature. This represents the saturated vapor pressure of water vapor at the wet-bulb temperature. Indicates absolute static pressure;

[0103] Calculate the air density at node v :

[0104]

[0105] In the above formula, Indicates air density, Indicates dry bulb temperature. Indicates absolute static pressure. Indicates relative humidity of the air. It represents the saturated vapor pressure of water vapor at dry-bulb temperature.

[0106] Calculation branch Volume air volume : At the starting node of branch e and end node The actual average wind speed is obtained by averaging the wind speeds measured at each location. Calculate the branches using the following formula. Volume air volume :

[0107]

[0108] In the above formula, Indicates branch Volumetric airflow of internal air, in units , Indicates branch The cross-sectional area at that location, , Indicates branch Actual average wind speed, unit ;

[0109] Calculate the branches using the following formula. mass air volume :

[0110]

[0111] In the above formula, Indicates branch The mass airflow of the internal airflow. , Indicates air density, Indicates branch The volumetric airflow of the internal airflow.

[0112] measuring point To the measuring point Corresponding branches are formed between them. The test section, branch The starting node Corresponding measuring points End node Corresponding measuring points Calculate this branch according to Bernoulli's equation. ventilation resistance for:

[0113]

[0114] In the above formula, Indicates the measuring point To the measuring point The ventilation resistance formed between the measuring sections, Pa; Indicates the measuring point The absolute static pressure of air at that location. Pa; Indicates the measuring point The absolute static pressure of air at that location. Pa; , They represent reading respectively and At that time, the corresponding measured values ​​of the mine ventilation parameter detector are corrected at the baseline. Pa; , These are the correction coefficients for the underground mine ventilation parameter measuring instrument and the benchmark-calibrated mine ventilation parameter measuring instrument, respectively. For measuring points Airflow density at the location; For measuring points Wind flow and wind speed at the location; For measuring points Airflow density at the location; For measuring points Wind flow and wind speed at the location; It is the acceleration due to gravity; For measuring points The gravitational pressure energy at that location; For measuring points The gravitational pressure energy at that location; for The average airflow density of the measurement section at the measurement point and measuring points After measuring the airflow density at each location, the average value was taken to obtain... Average airflow density of the measurement section .

[0115] Calculation branch Frictional wind resistance The method is as follows:

[0116]

[0117] In the formula, Indicates branch Frictional wind resistance, Indicates branch ventilation resistance, Indicates branch The volumetric airflow of the internal airflow.

[0118] S2, using Kruskal's algorithm to generate the minimum drag tree. ;

[0119] S3, increase the mass airflow of all branches mass air volume by Yu Shuxian This indicates that a system of wind pressure balance equations is established to solve for the mass air volume of Yu Shuxian. ;

[0120] S4, calculate the wind pressure error of the wind pressure balance equation, and obtain the correction value of the mass air volume of each coherent tree chord based on the wind pressure error;

[0121] S5, based on the correction value of the mass airflow of each coaxial tree chord, adjust the mass airflow of all branches. After iterative correction, and upon reaching the convergence condition after t iterations, the high-precision mass air volume of all branches is obtained. ;

[0122] S6 utilizes high-precision mass airflow across all branches. Calculate the high-precision volumetric air volume of all branches. .

[0123] In S2, the Kruskal algorithm is used to select the minimum drag tree. The method includes the following steps:

[0124] S201, Initialization Phase: For all branches According to frictional wind resistance Sort in ascending order to form an ordered branch set. = , Indicates the first One branch, Indicates the first Branches Frictional wind resistance; creating an empty set Initialize the full node set Full node set Store all nodes Initialize the disjoint-set data structure so that each node Independently forming single-element connected components, disjoint-set data structure and array that satisfies and , Represents the set of all nodes There are nodes , Represents the set of all nodes There is a unique node. ;

[0125] S202, Core Processing Stage: Algorithm Traversal Each branch For the current branch The starting node is obtained through the disjoint-set data structure operation. and end node , Indicates the current branch The starting node The root of the connected component. , Indicates the current branch End node The root of the connected component , This function represents the process of finding a node; when a node is detected... hour, If they belong to different connected components, then the corresponding branches join in Set, corresponding starting node Through disjoint-set data collection Operation merge For the corresponding connected components, update the parent and rank arrays of the disjoint-set data structure; when a connection is detected... Skip the branch. To prevent loops from forming; each successful addition of a new branch Post-detection termination conditions , Represents a set of nodes The number of nodes in express The number of branches in the set;

[0126] S203, Result Output Stage: When the algorithm meets the termination condition, record the result at this point. Minimum drag tree And output it.

[0127] The method for establishing the wind pressure balance equation in S3 includes the following steps:

[0128] S301, the ventilation network topology diagram belongs to the minimum wind resistance tree. Branches in This is referred to as a tree branch, and it does not belong to the minimum resistance tree in the ventilation network topology diagram. branch This is called a residual tree string. Each residual tree string corresponds to an independent loop in the ventilation network. The residual tree string airflow is extracted, and it is the airflow of its corresponding independent loop. The residual tree string airflow includes the residual tree string mass airflow. The volumetric air volume of Yu Shuxian Calculate the mass air volume of the remaining tree chord. The volumetric air volume of Yu Shuxian :

[0129] Assume the mass air volume of the remaining tree chord = Let the wind density of the remaining tree string be... Let the volume of the remaining tree string be the air volume. = , Then there is

[0130]

[0131] In the above formula, , Indicates the first The mass air volume of the remaining tree string Indicates the first The volume of windage of a single tree string. Indicates the first The airflow density of the remaining tree string;

[0132] S302, using Yu Shuxian's mass air volume Establishing the wind pressure balance equation includes the following steps:

[0133] The wind pressure balance equation for the independent loop is as follows:

[0134]

[0135] In the above formula, Indicates the first The branch and the first The topological relationship of an independent loop; Indicates the first Wind pressure in each branch; ;

[0136] Mass air volume of all branches Both are written as Yu Shuxian's mass air volume The function is used to establish a system of wind pressure balance equations, and the mass air volume of Yu Shuxian is obtained by solving the equations. :

[0137]

[0138] The above formula represents the expression by The mass air volume of the tree string The set of wind pressure balance equations. Indicates the first The system of wind pressure balance equations can be solved by finding the solution. The mass air volume of the tree string , Indicates the first branch among all branches Frictional wind resistance of each branch Indicates the first branch among all branches The airflow density of each branch, Indicates the first branch among all branches The wind pressure of the fan contained in each branch. Indicates the first branch among all branches The natural wind pressure contained in each branch. Indicates the first branch among all branches The mass air volume of each branch.

[0139] In S4, the wind pressure error of the wind pressure balance equation is calculated by performing a Taylor expansion of the wind pressure balance equation and simplifying the Jacobi matrix using the Seidel principle. The specific steps are as follows:

[0140] Wind pressure balance equations After the second iteration, the mass air volume of Yu Shuxian was obtained. :

[0141]

[0142] In the above formula, Indicates the first During the nth iteration Mass air volume of the remaining tree chord;

[0143] The first The wind pressure balance equation during iteration is expanded using the Taylor formula:

[0144]

[0145] In the above formula, Indicates the first A wind pressure balance equation Indicates the first At the +1st iteration, the... Residual tree chord mass air volume, Indicates the first During the nth iteration Correction value for mass air volume of the remaining tree chord. , Indicates the number of nodes. Indicates the number of branches. ;

[0146] Neglecting the second-order higher-order differentials in the above equation, then the... The linear approximation is:

[0147]

[0148] Rewrite the above equation in matrix form:

[0149]

[0150] The simplified calculation is as follows:

[0151]

[0152] In the above formula, Indicates the first The wind pressure balance equation for the first The mass air volume of the tree string The partial derivatives, first derivatives, and Jacobi coefficient matrix have strict diagonal dominance. Neglecting derivatives of the same order, i.e., neglecting off-diagonal terms in the coefficient matrix, yields:

[0153]

[0154] The above formula can be written as:

[0155]

[0156] Right now:

[0157]

[0158] In the above formula, Indicates the first The wind pressure error in the wind pressure balance equation.

[0159] The method for obtaining the correction value of the mass air volume of each coaxial tree chord based on wind pressure error in S4 is as follows:

[0160] Will Described as The function, derivation The specific expression:

[0161]

[0162] In the above formula, Indicates the first Quality flow of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the number of nodes. Indicates the number of branches. , ;

[0163] Combining the above equation with the wind pressure balance equation, we get:

[0164]

[0165] In the above formula, Indicates the first A wind pressure balance equation Indicates the first The branch and the first Topological relationships of individual loops, Indicates the first Frictional wind resistance of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the first The airflow density of each branch, Indicates the first The wind pressure of the fan contained in each branch. Indicates the first The natural wind pressure contained in each branch. Indicates branch Frictional wind resistance;

[0166] In the above formula right Taking the derivative, we get:

[0167]

[0168] In the above formula, Indicates the first Branches , represents a constant, therefore ,when right Differentiation is only possible when Its derivative is not zero, therefore Similarly,

[0169]

[0170] We can obtain:

[0171]

[0172] Represented as:

[0173]

[0174] In the above formula, Indicates the first During the nth iteration The mass air volume of the remaining tree string Indicates the first Branches and loops Topological relationships;

[0175] Yu Shuxian's mass air volume correction value The formula for calculation is:

[0176] .

[0177] Mass air volume for all branches in S5 The method for iterative correction is as follows:

[0178] No. sequence The mass air volume of each branch is :

[0179]

[0180] In the above formula, Indicates the number of nodes. Indicates the number of branches. , Indicates the first During the nth iteration Mass air volume of each branch Indicates the first Branches and loops Topological relationships, Indicates the first After the nth iteration Correction value for the mass air volume of the remaining tree chord.

[0181] The convergence condition in S5 is:

[0182] Iterate continuously on the quality airflow correction values ​​for each independent loop. Until the t-th iteration, the maximum independent loop mass airflow correction value is... Less than the set precision That is,

[0183]

[0184] The high-precision mass air volume of all branches can be obtained by solving the problem. = , .

[0185] The flow rate is 0.00001 to 0.01 kg / min.

[0186] S6 utilizes high-precision mass airflow across all branches. Calculate the high-precision volumetric air volume of all branches The method is as follows:

[0187]

[0188]

[0189] In the above formula, , This indicates that after the t-th iteration reaches the convergence condition, the th iteration... High-precision volumetric air volume for each branch. Indicates the first After the convergence condition is met in the nth iteration, the th... Mass air volume of each branch Indicates the first The airflow density of each branch.

[0190] The experiment in this embodiment is as follows:

[0191] (1) Verify the accuracy of the network solution method based on mass flow.

[0192] like Figure 3 The diagram shows the mine ventilation network topology. Arrows indicate branch numbers, and circles indicate node numbers. In this embodiment, there are 11 branches and 7 nodes. The column vector of the frictional resistance R is (1.3734, 1.4715, 1.1772, 0.9810, 0.7848, 2.9430, 0.5886, 3.9240, 4.1202, 5.8860, 2.2467). The fan pressure characteristic curve installed in branch 11 is: h = 1046.3 + 59q - 0.859q 2

[0193] Where h is the fan pressure and q is the fan air volume.

[0194] Using MATLAB software, the ventilation network data file in.txt was edited in the same path as the network_solution.m file. The traditional solution method based on volumetric flow rate (this method is existing technology, derived from the literature "An Algorithm for Mine Ventilation Network Solving Based on Loop Airflow Method") and the serial solution code based on mass-volume flow rate dual coupling were run respectively. The comparison of the output solution results is shown in Table 1.

[0195] Table 1 Comparison of Solution Results

[0196]

[0197] As shown above, the traditional calculation method based on volumetric flow rate results in significant errors in the volumetric air volume of each branch, ranging from 1% to 10%. However, the calculation method based on mass-volume flow rate dual coupling yields high-precision volumetric air volume with errors all less than 1%. This case demonstrates that when the density distribution of the mine ventilation network is uneven, the calculation method based on mass-volume flow rate dual coupling yields more accurate results.

[0198] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

[0199] This document uses specific embodiments to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are only intended to aid in understanding the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0200] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0201] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A high-precision network solution method based on mass-volume flow rate dual coupling, characterized in that, Includes the following steps: S1, Input the ventilation network topology diagram of the target mine, which includes several branches. Input each branch Data, calculate each node relative humidity at the location air density Calculate the volumetric airflow within each branch. Mass airflow M within the branch, branch ventilation resistance H, and frictional resistance. ; S2, using Kruskal's algorithm to generate the minimum drag tree. ; S3, increase the mass airflow of all branches mass air volume by Yu Shuxian This indicates that a system of wind pressure balance equations is established to solve for the mass air volume of Yu Shuxian. This includes the following steps: S301, the ventilation network topology diagram belongs to the minimum wind resistance tree. Branches in This is referred to as a tree branch, and it does not belong to the minimum resistance tree in the ventilation network topology diagram. branch This is called a residual tree string. Each residual tree string corresponds to an independent loop in the ventilation network. The residual tree string airflow is extracted, and it is the airflow of its corresponding independent loop. The residual tree string airflow includes the residual tree string mass airflow. The volumetric air volume of Yu Shuxian Calculate the mass air volume of the remaining tree chord. The volumetric air volume of Yu Shuxian : Assume the mass air volume of the remaining tree chord = Let the wind density of the remaining tree string be... Let the volume of the remaining tree string be the air volume. = , Then there is In the above formula, , Indicates the first The mass air volume of the remaining tree string Indicates the first The volume of windage of a single tree string. Indicates the first The airflow density of the remaining tree string; S302, using Yu Shuxian's mass air volume Establishing the wind pressure balance equation includes the following steps: The wind pressure balance equation for the independent loop is as follows: In the above formula, Indicates the first The branch and the first The topological relationship of an independent loop; Indicates the first Wind pressure in each branch; ; Mass air volume of all branches Both are written as Yu Shuxian's mass air volume The function is used to establish a system of wind pressure balance equations, and the mass air volume of Yu Shuxian is obtained by solving the equations. : The above formula represents the expression by The mass air volume of the tree string The set of wind pressure balance equations. Indicates the first The system of wind pressure balance equations can be solved by finding the solution. The mass air volume of the tree string , Indicates the first branch among all branches Frictional wind resistance of each branch Indicates the first branch among all branches The airflow density of each branch, Indicates the first branch among all branches The wind pressure of the fan contained in each branch. Indicates the first branch among all branches The natural wind pressure contained in each branch. Indicates the first branch among all branches The mass air volume of each branch; S4. Calculate the wind pressure error of the wind pressure balance equation, perform Taylor expansion on the wind pressure balance equation, and use the Seidel principle to simplify the Jacobi matrix. Based on the wind pressure error, obtain the correction value of the mass air volume of each co-tree chord. S5, based on the correction value of the mass airflow of each coaxial tree chord, adjust the mass airflow of all branches. After iterative correction, and upon reaching the convergence condition after t iterations, the high-precision mass air volume of all branches is obtained. ; S6 utilizes high-precision mass airflow across all branches. Calculate the high-precision volumetric air volume of all branches. .

2. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 1, characterized in that, In S2, the Kruskal algorithm is used to select the minimum drag tree. The method includes the following steps: S201, Initialization Phase: For all branches According to frictional wind resistance Sort in ascending order to form an ordered branch set. = , Indicates the first One branch, Indicates the first Branches Frictional wind resistance; creating an empty set Initialize the full node set Full node set Store all nodes Initialize the disjoint-set data structure so that each node Independently forming single-element connected components, disjoint-set data structure and array that satisfies and , Represents the set of all nodes There are nodes , Represents the set of all nodes There is a unique node. ; S202, Core Processing Stage: Algorithm Traversal Each branch For the current branch The starting node is obtained through the disjoint-set data structure operation. and end node , Indicates the current branch The starting node The root of the connected component. , Indicates the current branch End node The root of the connected component , This function represents the process of finding a node; when a node is detected... hour, If they belong to different connected components, then the corresponding branches join in Set, corresponding starting node Through disjoint-set data collection Operation merge For the corresponding connected components, update the parent and rank arrays of the disjoint-set data structure; when a connection is detected... Skip the branch. To prevent loops from forming; each successful addition of a new branch Post-detection termination conditions , Represents a set of nodes The number of nodes in express The number of branches in the set; S203, Result Output Stage: When the algorithm meets the termination condition, record the result at this point. Minimum drag tree And output it.

3. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 1, characterized in that, In S4, the wind pressure error of the wind pressure balance equation is calculated by performing a Taylor expansion of the wind pressure balance equation and simplifying the Jacobi matrix using the Seidel principle. The specific steps are as follows: Wind pressure balance equations After the second iteration, the mass air volume of Yu Shuxian was obtained. : In the above formula, Indicates the first During the nth iteration Mass air volume of the remaining tree chord; The first The wind pressure balance equation during iteration is expanded using the Taylor formula: In the above formula, Indicates the first A wind pressure balance equation Indicates the first At the +1st iteration, the... Residual tree chord mass air volume, Indicates the first During the nth iteration Correction value for mass air volume of the remaining tree chord. , Indicates the number of nodes. Indicates the number of branches. ; Neglecting the second-order higher-order differentials in the above equation, then the... The linear approximation is: Rewrite the above equation in matrix form: The simplified calculation is as follows: In the above formula, Indicates the first The wind pressure balance equation for the first The mass air volume of the tree string The partial derivatives, first derivatives, and Jacobi coefficient matrix have strict diagonal dominance. Neglecting derivatives of the same order, i.e., neglecting off-diagonal terms in the coefficient matrix, yields: The above formula can be written as: Right now: In the above formula, Indicates the first The wind pressure error in the wind pressure balance equation.

4. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 3, characterized in that, The method for obtaining the correction value of the mass air volume of each coaxial tree chord based on wind pressure error in S4 is as follows: Will Described as The function, derivation The specific expression: In the above formula, Indicates the first Quality flow of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the number of nodes. Indicates the number of branches. , ; Combining the above equation with the wind pressure balance equation, we get: In the above formula, Indicates the first A wind pressure balance equation Indicates the first The branch and the first Topological relationships of individual loops, Indicates the first Frictional wind resistance of each branch Indicates the first Branches and loops Topological relationships, Indicates the first The mass air volume of the remaining tree string, Indicates the first The airflow density of each branch, Indicates the first The wind pressure of the fan contained in each branch. Indicates the first The natural wind pressure contained in each branch. Indicates branch Frictional wind resistance; In the above formula right Taking the derivative, we get: In the above formula, Indicates the first Branches , represents a constant, therefore ,when right Differentiation is only possible when Its derivative is not zero, therefore Similarly, We can obtain: Represented as: In the above formula, Indicates the first During the nth iteration The mass air volume of the remaining tree string Indicates the first Branches and loops Topological relationships; Yu Shuxian's mass air volume correction value The formula for calculation is: 。 5. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 1, characterized in that, Mass air volume for all branches in S5 The method for iterative correction is as follows: No. sequence The mass air volume of each branch is : In the above formula, Indicates the number of nodes. Indicates the number of branches. , Indicates the first During the nth iteration Mass air volume of each branch Indicates the first Branches and loops Topological relationships, Indicates the first After the nth iteration Correction value for the mass air volume of the remaining tree chord.

6. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 5, characterized in that, The convergence condition in S5 is: Iterate continuously on the quality airflow correction values ​​for each independent loop. Until the t-th iteration, the maximum independent loop mass airflow correction value is... Less than the set precision That is, The high-precision mass air volume of all branches can be obtained by solving the problem. = , .

7. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 6, characterized in that, The flow rate is 0.00001 to 0.01 kg / min.

8. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 7, characterized in that, S6 utilizes high-precision mass airflow across all branches. Calculate the high-precision volumetric air volume of all branches The method is as follows: In the above formula, , This indicates that after the t-th iteration reaches the convergence condition, the th iteration... High-precision volumetric air volume for each branch. Indicates the first After the convergence condition is met in the nth iteration, the th... Mass air volume of each branch Indicates the first The airflow density of each branch.

9. The high-precision network solution method based on mass-volume flow rate dual coupling according to claim 1, characterized in that, In each node of S1 Set up measurement points at the location to obtain data for each branch. The data.

Images