A method for automatically responding to natural gas pipeline operation plans

Abstract

The present invention provides a method for automatically responding to a natural gas pipeline operation plan, comprising the following steps: 1) Based on a pipeline network simulation model, simulate and calculate the operation plan, import the feasible operation plan into the operation plan database, and realize digital management of the operation plan, including the addition, modification and deletion of the operation plan; 2) Automatic response to the operation plan that meets the safe operation of the pipeline and the upstream and downstream production needs is realized through the operation plan database, and the automatic response includes automatic response to normal working conditions and emergency working conditions. 3) The operation plan is comprehensively evaluated by using the "hierarchy analysis method + fuzzy membership function method" comprehensive evaluation method; 4) In view of the shortcoming that the automatic response of the database cannot guarantee the optimality, the optimization algorithm automatic response module can be called to solve the optimal operation plan through the pipeline network operation optimization model. The present invention can be widely used in the field of natural gas pipeline networks, improve the decision-making efficiency of on-site dispatchers, and ensure the safe and efficient operation of the pipeline network system.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas pipeline network operation, and in particular to an automatic response method for operation schemes based on pipeline network simulation and pipeline network operation optimization. Background Art

[0002] With the development of technology, long-distance natural gas transmission pipelines have evolved from a single-gas source, single-pipe, non-pressurized transmission mode to a multi-gas source, multi-pipe, and multiple compression station transmission mode. The distribution of gas volume from multiple sources, the selection of compressor startup plans, the selection of pressure ratios for each compressor station, and the handling of abnormal operating conditions have led to the complexity of pipeline operation plans. At present, my country's natural gas pipeline operation plans mostly rely on traditional methods for data management, which is cumbersome and error-prone, and has low data value density. There is a lack of scientific methods for unified management of large-scale operation plans. In the actual operation of the pipeline, most operation plans are qualitatively analyzed and formulated by technical personnel based on experience. When considering multiple different compressor startup plans, different pressure ratios, and different power operation plans, it is difficult to make accurate judgments based on experience. As the pipeline system gradually expands, efficient data management technology and optimization tools are urgently needed to assist in the formulation of operation plans, reduce pipeline transportation costs, and improve economic benefits.

[0003] In the process of natural gas pipeline transportation, there will inevitably be energy consumption, which is divided into direct consumption and indirect consumption. Among them, direct energy consumption refers to the energy consumption of pressurization at the compressor station and the energy consumption of pipeline resistance loss, etc.; indirect energy consumption refers to the loss caused by gas leakage during transportation. The amount of energy consumption mainly depends on the pipeline operation plan. The main way to reduce pipeline operation costs is to reasonably choose a pipeline operation plan. Through scientific planning of gas supply and compressor startup plans along the line, the gas pipeline can complete the task of transporting the specified amount of natural gas to downstream users under the premise of stable and safe operation, ensuring users' gas use while reducing energy consumption.

[0004] When selecting a natural gas pipeline operation plan, the main consideration is how to transport the same amount of gas with the lowest possible energy consumption, ensure the user's safe, continuous and stable gas use, and improve economic benefits. The response methods of the operation plan mainly include optimization methods, simulation software simulation calculations and expert experience. The optimization method can ensure the optimality of the operation plan, but due to the complexity of the mathematical model and the large scale of the solution, it may not be possible to obtain a feasible solution or an optimal solution, and the solution time is long. Simulation software simulation calculations and expert experience can obtain feasible solutions, but the optimality of the operation plan cannot be guaranteed. Therefore, it is necessary to combine the two methods to establish an automatic response method system for the natural gas pipeline operation plan to ensure the optimality of the operation plan on the basis of meeting the pipeline gas transmission requirements. Summary of the invention

[0005] The present invention mainly overcomes the deficiencies in the prior art and aims to provide a method for automatically responding to a natural gas pipeline operation plan based on pipeline network simulation and pipeline network operation optimization.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A natural gas pipeline operation plan automatic response method, characterized in that the automatic response method comprises the following steps:

[0008] S1: Based on the database design principles and demand analysis, a natural gas pipeline network operation plan database was established. The startup plan information table includes 22 operating parameters, including the gas volume of each gas source, pipeline interconnection, pipeline gas transmission capacity, total compressor power, and pipeline storage; the operation parameter information table includes detailed parameters such as the number of stations started, station flow, inlet pressure, outlet pressure, pressure ratio, speed, calculated power, etc.

[0009] S2: Based on the pipe network simulation model, simulate the operation plan, import the feasible operation plan into the designed operation database, and realize the digital management of the operation plan, including the addition, modification and deletion of the operation plan;

[0010] S3: Automatic response to the optimal operation plan with safe and stable operation of the pipeline and low energy consumption is achieved through the operation plan database. The automatic response includes automatic response under normal operating conditions and emergency conditions. Normal operating conditions refer to the pipeline being able to meet the gas demand of downstream users under conventional gas supply conditions, without the need for emergency gas sources from gas storage facilities or interconnected pipelines to coordinate gas volume; emergency conditions refer to a serious imbalance in gas supply and sales due to abnormalities in the upstream gas source of the pipeline, the compressor stations along the pipeline, the pipeline itself, or downstream users. The present invention only discusses emergency gas supply events caused by excessive or insufficient gas supply from the upstream gas source of the pipeline, which are scenarios where the gas supply from the gas source is insufficient and the gas supply from the gas source exceeds the gas consumption of the user;

[0011] S4: The comprehensive evaluation system of "analytic hierarchy process + fuzzy membership function method" is used to comprehensively evaluate the operation plan and sort the evaluation results, so that users can obtain the best operation plan that meets the working conditions in a relatively short time;

[0012] S5: To address the shortcoming that the automatic response of the database cannot guarantee optimality, an automatic response module based on an optimization algorithm can be used. The automatic response module based on the optimization algorithm can achieve the optimization solution of the pipeline under the conditions of certain gas supply and uncertain gas supply, and complete the full-time operation optimization of the natural gas pipeline. This module mainly solves the optimal operation plan of the natural gas pipeline network by calling the pipeline network operation optimization model. The operation plan includes the optimal compressor startup plan along the line and the optimal gas supply of the gas source.

[0013] Furthermore, the specific steps of step S2 are:

[0014] Using pipeline network simulation software, based on pipeline hydraulic and thermal calculations, with basic physical parameters of pipelines and operating control conditions as boundaries, combined with the operating characteristics of equipment such as compressors in the pipeline network, a steady-state simulation model of the pipeline network is established;

[0015] Based on the steady-state simulation model of the pipeline network, the gas transmission capacity analysis of the operation scheme is carried out. Through simulation calculations of different operation schemes, the impact of different compressor startup schemes on pipeline gas transmission capacity, pipeline storage, and total power of trunk compressors is analyzed, and the operation scheme that meets the gas transmission capacity requirements is imported into the operation scheme database;

[0016] The operation plan database management mainly realizes the functions of adding, modifying and deleting operation plans in the database. The specific implementation method is: using the database as a support, creating execution statements, and finally processing execution management operations.

[0017] Furthermore, the specific steps of step S3 are:

[0018] Based on a large number of operation plans in the operation plan database, the database fuzzy query technology is adopted. Under normal working conditions, four query modes can be used, namely flow query mode, compressor station query mode, flow + compressor station query mode and compressor startup plan query mode. Under emergency conditions, two query modes can be used, namely under-quantity query mode and over-quantity query mode.

[0019] According to the actual working conditions on site, select the appropriate query method to automatically respond to pipeline operation plans under different working conditions.

[0020] Furthermore, the specific steps of step S4 are:

[0021] After querying the operation plans that meet the conditions, the evaluation steps are combined with the "hierarchy analysis method + fuzzy membership function method" comprehensive evaluation method: ① Construct a hierarchical analysis structure of the pipeline operation plan database, in which the target layer is the pipeline operation plan evaluation score, the criterion layer is the operation safety and economy, and the indicator layer is the pipeline inventory, pressure fluctuation range, number of gas source points, pipeline gas transmission capacity, and boosting power consumption; ② Construct a judgment matrix to check the consistency of the criterion layer and the indicator layer; ③ Calculate the indicator weight; ④ Dimensionless processing of pipeline operation plan evaluation indicators; ⑤ Comprehensive evaluation calculation of pipeline operation plans.

[0022] The evaluation scores of the startup plan information and operating parameter information in the operation plan are entered into the database to facilitate on-site personnel to quickly screen out the operation plan with higher safety.

[0023] Furthermore, the specific steps of step S5 are:

[0024] Call the automatic response module based on the optimization algorithm and choose to use the model with known or unknown gas supply according to the actual situation on site;

[0025] Under the condition of known gas supply volume, combined with known parameters such as gas supply volume, node distribution volume, compression performance parameters, based on the optimization model, with the lowest operating energy consumption as the optimization goal, the optimal operation plan of the pipeline is solved. The operation plan includes the commissioning mode of the compressor station, the number of compressors started, the inlet and outlet pressures, the compressor speed and the single-unit power.

[0026] When the gas supply volume is unknown, the gas supply volume of the gas source changes from a known quantity to an optimization variable. Combined with known parameters such as the node distribution volume and compression performance parameters, the objective function and constraints in the optimization model are the same as those under the known conditions of the gas supply volume. The optimal operation plan of the pipeline is solved. The operation plan includes the gas supply volume of the gas source, the commissioning mode of the compressor station, the number of compressors in operation, the inlet and outlet pressures, the compressor speed and the single-unit power.

[0027] The objective function expression of the pipeline operation optimization model under the condition that the gas supply volume of the gas source in step S5 is known is:

[0028]

[0029] Where, f is the energy consumption cost of the compressor station, yuan; is the total number of compressor stations along the pipeline, seats; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor, yuan / h; W l,k is the power of the lth compressor of the kth compressor station, kW; t l is the working time of the compressor of the lth compressor station, h.

[0030] The gas flow constraint is:

[0031]

[0032]

[0033] In the formula, is the flow rate into node i, 10 4 m 3 / d; is the outflow of node i, 10 4 m 3 / d;Q j is the flow rate from the pipe segment j connected to the node i into the node, 104 m 3 / d; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum demand flow of demand node d, 10 4 m 3 / d;Q d is the demand flow of demand node d, 10 4 m 3 / d.

[0034] The pipeline compressor station constraints are:

[0035]

[0036]

[0037]

[0038] Where P j is the pressure of the jth pipe section, MPa; is the maximum allowable operating pressure of the pipe section, MPa; P dn is the demand node pressure, MPa; is the minimum delivery pressure at the demand node, MPa; N cs is the number of compressor stations put into operation along the line; is the total number of compressor stations along the line.

[0039] The compressor constraints are:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048] In the formula, is the total number of compressors in the lth compressor station; r l is the speed of the kth compressor in the lth compressor station, rpm; is the minimum speed allowed for the kth compressor in the lth compressor station, rpm; is the maximum speed allowed for the kth compressor in the lth compressor station, rpm; Q l,k is the flow rate of the kth compressor in the lth compressor station, m 3 / d; is the surge flow rate of the kth compressor in the lth compressor station, m 3 / d; is the stagnant flow of the kth compressor in the lth compressor station, m 3 / d;ε l,k is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio of the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station, MPa; is the maximum outlet pressure allowed by the kth compressor in the lth compressor station, MPa; W l,k is the power of the kth compressor in the lth compressor station, kW; is the minimum power allowed for the kth compressor in the lth compressor station, kW; The maximum power allowed for the kth compressor in the lth compressor station, kW.

[0049] The objective function expression of the pipeline operation optimization model under the condition of unknown gas source supply volume in step S5 is:

[0050]

[0051] Where, f is the energy consumption cost of the compressor station, yuan; is the total number of compressor stations along the pipeline, seats; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor, yuan / h; W l,k is the power of the lth compressor of the kth compressor station, kW; t l is the working time of the compressor of the lth compressor station, h.

[0052] The gas supply quantity constraint of the gas source is:

[0053]

[0054] In the formula, Q s is the supply flow rate of gas source s, 10 4 m 3 / d; is the minimum supply flow rate of gas source s, 10 4 m 3 / d; is the maximum supply flow rate of gas source s, 10 4 m 3 / d.

[0055] The gas flow constraint is:

[0056]

[0057]

[0058] In the formula, is the flow rate into node i, 10 4 m 3 / d; is the outflow of node i, 10 4 m 3 / d; is the flow rate of the pipe segment j connected to the node into the node, 10 4 m 3 / d; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum node requirement, 10 4 m 3 / d;Q dn is the node demand, 10 4 m 3 / d;.

[0059] The pipeline compressor station constraints are:

[0060]

[0061]

[0062]

[0063] Where P j is the pressure of the jth pipe section, MPa; is the maximum allowable operating pressure of the pipe section, MPa; P dn is the demand node pressure, MPa; is the minimum delivery pressure at the demand node, MPa; N cs is the number of compressor stations put into operation along the line; is the total number of compressor stations along the line.

[0064] The compressor constraints are:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] In the formula, is the total number of compressors in the lth compressor station; r l is the speed of the kth compressor in the lth compressor station, rpm; is the minimum speed allowed for the kth compressor in the lth compressor station, rpm; is the maximum speed allowed for the kth compressor in the lth compressor station, rpm; Q l,k is the flow rate of the kth compressor in the lth compressor station, m 3 / d; is the surge flow rate of the kth compressor in the lth compressor station, m 3 / d; is the stagnant flow of the kth compressor in the lth compressor station, m 3 / d;ε l,k is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio of the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station, MPa; is the maximum outlet pressure allowed by the kth compressor in the lth compressor station, MPa; W l,k is the power of the kth compressor in the lth compressor station, kW; is the minimum power allowed for the kth compressor in the lth compressor station, kW; The maximum power allowed for the kth compressor in the lth compressor station, kW.

[0074] Beneficial effects:

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] Based on the pipeline network simulation theory, pipeline network operation optimization theory and comprehensive evaluation theory, combined with the advantages of pipeline network simulation technology, pipeline network operation optimization technology and database technology, an automatic response method for natural gas pipeline network operation scheme is proposed. First, according to the demand analysis and database construction principles, the operation scheme database structure is designed. Based on the pipeline simulation model, the gas transmission capacity of the operation scheme under different compressor startup modes is analyzed to provide data support for the operation scheme database. In order to realize the scheme comparison in the operation scheme database, the "hierarchy analysis method + fuzzy membership function method" is used to establish a comprehensive evaluation method, and the operation scheme is comprehensively evaluated considering technical feasibility and economy. Based on the database fuzzy query technology, a pipeline operation scheme query method under normal and emergency conditions is proposed. Combined with the comprehensive evaluation theory of the operation scheme, an automatic response method based on the operation scheme database is formed. Through the analysis of the characteristics of the operation scheme database and the optimization algorithm, the necessity of the optimization model and the relationship between the two automatic response methods are explained. Taking the minimum energy consumption of pipeline compressor as the objective function and considering constraints such as node flow balance, an optimization model of pipeline operation scheme under different gas source conditions is established to achieve the optimization solution of pipeline network operation scheme under conditions with known gas supply volume and unknown gas supply volume.

[0077] This method can not only achieve rapid matching of pipeline network operation plans and improve the decision-making efficiency of on-site personnel, but also ensure the economy of natural gas pipeline operation plans through optimization algorithms and comprehensive evaluation methods. In addition to being used for automatic response to natural gas pipeline network operation plans, the present invention can also provide theoretical references for water supply networks, finished oil gathering and transportation networks, etc., and has wide application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a flow chart of the automatic response method system of the natural gas pipeline operation scheme provided by the present invention;

[0079] Figure 2 It is a schematic diagram of an automatic response process of a pipeline operation plan based on an operation plan database provided by the present invention;

[0080] Figure 3 It is a schematic diagram of an automatic response flow of a pipeline operation scheme based on an optimization algorithm database provided by the present invention;

[0081] Figure 4 This is a flow query result diagram provided by an embodiment of the present invention;

[0082] Figure 5 is a diagram of comprehensive evaluation results of a natural gas pipeline operation plan provided by an embodiment of the present invention;

[0083] Figure 6 It is a schematic diagram of an automatic response module of a natural gas pipeline operation plan based on an optimization algorithm provided by an example of the present invention. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0085] Example:

[0086] A natural gas pipeline operation plan automatic response method, characterized in that the automatic response method comprises the following steps:

[0087] S1: Based on the database design principles and demand analysis, a natural gas pipeline network operation plan database was established. The startup plan information table includes 22 operating parameters, including the gas volume of each gas source, pipeline interconnection, pipeline gas transmission capacity, total compressor power, and pipeline storage; the operation parameter information table includes detailed parameters such as the number of stations started, station flow, inlet pressure, outlet pressure, pressure ratio, speed, calculated power, etc.

[0088] S2: Based on the pipe network simulation model, simulate the operation plan, import the feasible operation plan into the designed operation database, and realize the digital management of the operation plan, including the addition, modification and deletion of the operation plan;

[0089] S3: Automatic response to the optimal operation plan with safe and stable operation of the pipeline and low energy consumption is achieved through the operation plan database. The automatic response includes automatic response under normal operating conditions and emergency conditions. Normal operating conditions refer to the pipeline being able to meet the gas demand of downstream users under conventional gas supply conditions, without the need for emergency gas sources from gas storage facilities or interconnected pipelines to coordinate gas volume; emergency conditions refer to a serious imbalance in gas supply and sales due to abnormalities in the upstream gas source of the pipeline, the compressor stations along the pipeline, the pipeline itself, or downstream users. The present invention only discusses emergency gas supply events caused by excessive or insufficient gas supply from the upstream gas source of the pipeline, which are scenarios where the gas supply from the gas source is insufficient and the gas supply from the gas source exceeds the gas consumption of the user;

[0090] S4: The comprehensive evaluation system of "analytic hierarchy process + fuzzy membership function method" is used to comprehensively evaluate the operation plan and sort the evaluation results, so that users can obtain the best operation plan that meets the working conditions in a relatively short time;

[0091] S5: To address the shortcoming that the automatic response of the database cannot guarantee optimality, an automatic response module based on an optimization algorithm can be used. The automatic response module based on the optimization algorithm can achieve the optimization solution of the pipeline under the conditions of certain gas supply and uncertain gas supply, and complete the full-time operation optimization of the natural gas pipeline. This module mainly solves the optimal operation plan of the natural gas pipeline network by calling the pipeline network operation optimization model. The operation plan includes the optimal compressor startup plan along the line and the optimal gas supply of the gas source.

[0092] Furthermore, the specific steps of step S2 are:

[0093] Using pipeline network simulation software, based on pipeline hydraulic and thermal calculations, with basic physical parameters of pipelines and operating control conditions as boundaries, combined with the operating characteristics of equipment such as compressors in the pipeline network, a steady-state simulation model of the pipeline network is established;

[0094] Based on the steady-state simulation model of the pipeline network, the gas transmission capacity analysis of the operation scheme is carried out. Through simulation calculations of different operation schemes, the impact of different compressor startup schemes on pipeline gas transmission capacity, pipeline storage, and total power of trunk compressors is analyzed, and the operation scheme that meets the gas transmission capacity requirements is imported into the operation scheme database;

[0095] The operation plan database management mainly realizes the functions of adding, modifying and deleting operation plans in the database. The specific implementation method is: using the database as a support, creating execution statements, and finally processing execution management operations.

[0096] Furthermore, the specific steps of step S3 are:

[0097] Based on a large number of operation plans in the operation plan database, the database fuzzy query technology is adopted. Under normal working conditions, four query modes can be used, namely flow query mode, compressor station query mode, flow + compressor station query mode and compressor startup plan query mode. Under emergency conditions, two query modes can be used, namely under-quantity query mode and over-quantity query mode.

[0098] According to the actual working conditions on site, select the appropriate query method to automatically respond to pipeline operation plans under different working conditions.

[0099] Furthermore, the specific steps of step S4 are:

[0100] After querying the operation plans that meet the conditions, the evaluation steps are combined with the "hierarchy analysis method + fuzzy membership function method" comprehensive evaluation method: ① Construct a hierarchical analysis structure of the pipeline operation plan database, in which the target layer is the pipeline operation plan evaluation score, the criterion layer is the operation safety and economy, and the indicator layer is the pipeline inventory, pressure fluctuation range, number of gas source points, pipeline gas transmission capacity, and boosting power consumption; ② Construct a judgment matrix to check the consistency of the criterion layer and the indicator layer; ③ Calculate the indicator weight; ④ Dimensionless processing of pipeline operation plan evaluation indicators; ⑤ Comprehensive evaluation calculation of pipeline operation plans.

[0101] The evaluation scores of the startup plan information and operating parameter information in the operation plan are entered into the database to facilitate on-site personnel to quickly screen out the operation plan with higher safety.

[0102] Furthermore, the specific steps of step S5 are:

[0103] Call the automatic response module based on the optimization algorithm and choose to use the known or unknown gas supply model according to the actual situation on site;

[0104] Under the condition of known gas supply volume, combined with known parameters such as gas supply volume, node distribution volume, compression performance parameters, based on the optimization model, with the lowest operating energy consumption as the optimization goal, the optimal operation plan of the pipeline is solved. The operation plan includes the commissioning mode of the compressor station, the number of compressors started, the inlet and outlet pressures, the compressor speed and the single-unit power.

[0105] When the gas supply volume is unknown, the gas supply volume of the gas source changes from a known quantity to an optimization variable. Combined with known parameters such as the node distribution volume and compression performance parameters, the objective function and constraints in the optimization model are the same as those under the known conditions of the gas supply volume. The optimal operation plan of the pipeline is solved. The operation plan includes the gas supply volume of the gas source, the commissioning mode of the compressor station, the number of compressors in operation, the inlet and outlet pressures, the compressor speed and the single-unit power.

[0106] The objective function expression of the pipeline operation optimization model under the condition of known gas source supply volume in step S5 is:

[0107]

[0108] Where, f is the energy consumption cost of the compressor station, yuan; is the total number of compressor stations along the pipeline, seats; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor, yuan / h; W l,k is the power of the lth compressor of the kth compressor station, kW; t l is the working time of the compressor of the lth compressor station, h.

[0109] The gas flow constraint is:

[0110]

[0111]

[0112] In the formula, is the flow rate into node i, 10 4 m 3 / d; is the outflow of node i, 10 4 m 3 / d; is the flow rate of the pipe segment j connected to the node i into the node, 104 m 3 / d; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum demand flow of demand node d, 10 4 m 3 / d;Q d is the demand flow of demand node d, 10 4 m 3 / d;.

[0113] The pipeline compressor station constraints are:

[0114]

[0115]

[0116]

[0117] Where P j is the pressure of the jth pipe section, MPa; is the maximum allowable operating pressure of the pipe section, MPa; P dn is the demand node pressure, MPa; is the minimum delivery pressure at the demand node, MPa; N cs is the number of compressor stations put into operation along the line; is the total number of compressor stations along the line.

[0118] The compressor constraints are:

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127] In the formula, is the total number of compressors in the lth compressor station; r l is the speed of the kth compressor in the lth compressor station, rpm; is the minimum speed allowed for the kth compressor in the lth compressor station, rpm; is the maximum speed allowed for the kth compressor in the lth compressor station, rpm; Q l,k is the flow rate of the kth compressor in the lth compressor station, m 3 / h; is the surge flow rate of the kth compressor in the lth compressor station, m 3 / h; is the stagnant flow of the kth compressor in the lth compressor station, m 3 / h; ε l,k is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio of the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station, MPa; is the maximum outlet pressure allowed by the kth compressor in the lth compressor station, MPa; W l,k is the power of the kth compressor in the lth compressor station, kW; is the minimum power allowed for the kth compressor in the lth compressor station, kW; The maximum power allowed for the kth compressor in the lth compressor station, kW.

[0128] The objective function expression of the pipeline operation optimization model under the condition of unknown gas source supply volume in step S5 is:

[0129]

[0130] Where, f is the energy consumption cost of the compressor station, yuan; is the total number of compressor stations along the pipeline, seats; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor, yuan / h; W l,k is the power of the lth compressor of the kth compressor station, kW; t l is the working time of the compressor of the lth compressor station, h.

[0131] The gas supply quantity constraint of the gas source is:

[0132]

[0133] In the formula, Q s is the supply flow rate of gas source s, 10 4 m 3 / d; is the minimum supply flow rate of gas source s, 10 4 m 3 / d; is the maximum supply flow rate of gas source s, 10 4 m 3 / d.

[0134] The gas flow constraint is:

[0135]

[0136]

[0137] In the formula, is the flow rate into node i, 10 4 m 3 / d; is the outflow of node i, 10 4 m 3 / d; is the flow rate of the pipe segment j connected to the node into the node, 10 4 m 3 / d; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum node requirement, 10 4 m 3 / d;Q dn is the node demand, 10 4 m 3 / d;.

[0138] The pipeline compressor station constraints are:

[0139]

[0140]

[0141]

[0142] Where P j is the pressure of the jth pipe section, MPa; is the maximum allowable operating pressure of the pipe section, MPa; P dn is the demand node pressure, MPa; is the minimum delivery pressure at the demand node, MPa; N cs is the number of compressor stations put into operation along the line; is the total number of compressor stations along the line.

[0143] The compressor constraints are:

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152] In the formula, is the total number of compressors in the lth compressor station; r l is the speed of the kth compressor in the lth compressor station, rpm; is the minimum speed allowed for the kth compressor in the lth compressor station, rpm; is the maximum speed allowed for the kth compressor in the lth compressor station, rpm; Q l,k is the flow rate of the kth compressor in the lth compressor station, m 3 / h; is the surge flow rate of the kth compressor in the lth compressor station, m 3 / h; is the stagnant flow of the kth compressor in the lth compressor station, m 3 / h; ε l,k is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio of the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station, MPa; is the maximum outlet pressure allowed by the kth compressor in the lth compressor station, MPa; W l,k is the power of the kth compressor in the lth compressor station, kW; is the minimum power allowed for the kth compressor in the lth compressor station, kW; The maximum power allowed for the kth compressor in the lth compressor station, kW.

[0153] Embodiment 1:

[0154] Assume that a natural gas pipeline network needs to transport gas to the east of compressor station C with a capacity range of 3500-4000m 3 / d, respond to the operation plan of corresponding output in the operation plan database according to the on-site demand, and sort them according to the comprehensive evaluation score.

[0155] (1) Fuzzy query statements

[0156] The specific query statement is: SELECT * FROM `kjfa`

[0157] WHERE GDSQNL_A BETWEEN 3500AND 4000

[0158] ORDER BY GXYSJZGL

[0159] (2) Traffic query results

[0160] In the running solution database, according to the above fuzzy query statement, the query results are as follows: Figure 4 As shown in the figure, there are 257 sets of operation plans. Among them, the gas transmission volume to the east of compressor station C is 3500~4000×10 4 m 3 / d range.

[0161] (3) Comprehensive evaluation of operation plans

[0162] The "hierarchy analysis method + fuzzy membership function method" comprehensive evaluation system is used to comprehensively evaluate the selected operation plans, and the plans are ranked according to their scores, such as Figure 5 In addition to the comprehensive evaluation value of the scheme, the detailed scores of each indicator are also displayed, including the maximum gas transmission volume of the pipeline, compressor power, pressure fluctuation range, pipeline storage value, etc. For example, the operation scheme with ID 269 has a large gas transmission capacity of 4733.8×10 4 m 3 / d, but due to its higher compressor power and wider pressure fluctuation range, its score is lower than other solutions.

[0163] It can be seen that the proposed automatic response method based on the operation plan database based on database fuzzy query technology and comprehensive evaluation method can be well applied to the actual site. According to actual needs, the operation plan database automatically responds to the operation plan that meets the gas conditions of downstream users, operates safely and stably, and has good economic benefits, providing guidance for on-site decision-making.

[0164] Embodiment 2:

[0165] According to the actual pipeline data on a certain day, the gas supply of gas source 1 is 244.96×104m 3 / d, the gas supply of gas source 2 is 1575.1661×10 4 m 3 / d, and the distribution volume of each distribution point along the pipeline is shown in Table 1. The startup plan of the natural gas pipeline network compressor is CSA-1+CSB-1+CSC-2+CSD-2+CSE-2+CSF-1+CSG-3, and the operating energy consumption cost is about 944,800 yuan.

[0166] Table 1 Output point output table

[0167]

[0168]

[0169] The gas supply volume of each gas source and the number of distribution points along the pipeline are imported into the automatic response module of the pipeline operation plan based on the optimization algorithm, and the built-in solver is called to solve the optimization model, such as Figure 6 shown.

[0170] After solving the problem, the startup plan of the natural gas pipeline network compressor was adjusted to CSA-2+CSB-2+CSC-2+CSD-2+CSE-2+CSF-2+CSG-3. The operating energy consumption cost was 9.0759 million yuan, a year-on-year decrease of 3.9%. The detailed solution results are shown in Table 2.

[0171] Table 2

[0172]

[0173]

[0174] The present invention provides an automatic response method for an operation scheme based on pipeline network simulation and pipeline network operation optimization. Based on the pipeline network simulation theory, pipeline network operation optimization theory and comprehensive evaluation theory, and combining the advantages of pipeline network simulation technology, pipeline network operation optimization technology and database technology, an automatic response method for a natural gas pipeline network operation scheme is proposed. First, the operation scheme database structure is designed according to demand analysis and database construction principles. Based on the pipeline simulation model, the gas transmission capacity of the operation scheme under different compressor startup modes is analyzed to provide data support for the operation scheme database. In order to realize the scheme comparison in the operation scheme database, a comprehensive evaluation method is established by using the "hierarchy analysis method + fuzzy membership function method", and the operation scheme is comprehensively evaluated considering technical feasibility and economy. Based on the database fuzzy query technology, a pipeline operation scheme query method under normal working conditions and emergency working conditions is proposed, and combined with the comprehensive evaluation theory of the operation scheme, an automatic response method based on the operation scheme database is formed. By analyzing the characteristics of the operation scheme database and the optimization algorithm, the necessity of the optimization model and the relationship between the two automatic response methods are explained. Taking the minimum energy consumption of pipeline compressor as the objective function and considering constraints such as node flow balance, an optimization model of pipeline operation scheme under different gas source conditions is established to achieve the optimization solution of pipeline network operation scheme under conditions with known gas supply volume and unknown gas supply volume.

[0175] This method can not only achieve rapid matching of pipeline network operation plans and improve the decision-making efficiency of on-site personnel, but also ensure the economy of natural gas pipeline operation plans through optimization algorithms and comprehensive evaluation methods. In addition to being used for automatic response to natural gas pipeline network operation plans, the present invention can also provide theoretical references for water supply networks, finished oil gathering and transportation networks, etc., and has wide application value.

Claims

1. A natural gas pipeline operation plan automatic response method, characterized in that: The following steps are involved: S1: Establishing a natural gas pipeline operation plan database, wherein the natural gas pipeline operation plan database includes a startup plan information table and an operation parameter information table; The startup plan information table includes the gas volume of each gas source, pipeline interconnection status, pipeline gas transmission capacity, compressor total power, and pipeline storage parameters; The operating parameter information table includes the number of stations in operation, inlet flow, inlet pressure, outlet pressure, pressure ratio, speed, and calculated power parameters; S2: Conduct pipeline simulation on the operation plan, import the feasible operation plan into the pipeline operation plan database, and realize digital management of the operation plan, including adding, modifying and deleting the operation plan; S3: Make intelligent decisions based on the operation plans in the pipeline operation plan database, including intelligent decisions under normal working conditions and emergency working conditions; normal working conditions refer to the situation where the pipeline can meet the gas demand of users under the condition of conventional gas source supply, and no gas volume coordination is required; emergency working conditions refer to the situation where the gas supply of the gas source is insufficient and the gas supply of the gas source exceeds the gas consumption of the user; S4: The comprehensive evaluation system of "analytic hierarchy process + fuzzy membership function method" is used to comprehensively evaluate the operation plan and sort the evaluation results, so that users can obtain the best operation plan that meets the working condition requirements in a relatively short time; S5: The intelligent decision-making module calls a pipeline operation optimization model with minimum energy consumption as the optimization goal. The pipeline optimization model includes a pipeline operation optimization model under the condition of known gas source supply and a pipeline operation optimization model under the condition of unknown gas source supply. The model is solved to obtain the optimal operation plan of the natural gas pipeline. The pipeline operation plan under the condition of known gas source supply includes the optimal compressor startup plan along the line. The pipeline operation plan under the condition of unknown gas source supply includes the optimal compressor startup plan along the line and the optimal gas source supply.

2. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The specific steps of S2 include: S201: Using pipeline simulation software, considering pipeline hydraulic calculation and thermal calculation, taking pipeline physical parameters and operation control conditions as boundaries, and combining the operation characteristics of compressors in the pipeline network, a pipeline steady-state simulation model is established; S202: Based on the steady-state simulation model of the pipeline network, conduct pipeline gas transmission capacity analysis, simulate and calculate different operation plans, analyze the impact of different operation plans on pipeline gas transmission capacity, and import the operation plan that meets the pipeline gas transmission capacity requirements into the pipeline operation plan database; S203: The pipeline operation plan database creates execution statements to implement the functions of adding, modifying and deleting operation plans in the database.

3. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The specific steps of S3 are: S301: Using database fuzzy query technology to query the pipeline operation plan under normal working conditions and emergency working conditions; S302: The normal operating condition query has four query modes: flow query mode, compressor station query mode, flow + compressor station query mode and compressor startup plan query mode; S303: There are two query modes under the emergency condition: under-quantity query mode and over-quantity query mode.

4. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The specific steps of S4 are: S401: constructing a pipeline operation plan hierarchical analysis structure, wherein the target layer is the pipeline operation plan evaluation score, the criterion layer is the operation safety and economy, and the indicator layer is the pipeline storage, pressure fluctuation range, number of gas source points, pipeline gas transmission capacity, and boosting power consumption; S402: construct a judgment matrix to perform consistency check on the criterion layer and the indicator layer; S403: The square root method is used to calculate the indicator weight, and the calculation formula is: In the formula, a ij is the element in the i-th row and j-th column of the judgment matrix; M i is the product of the elements in the i-th row of the judgment matrix; is the geometric mean of the product of the elements in the i-th row of the judgment matrix; w i is the indicator weight; S404: Dimensionless processing of pipeline operation plan evaluation indicators; S405: The evaluation value of each index is obtained by using a linear weighted method. The calculation process is: In the formula, F i is the evaluation value of the i-th indicator layer; t is the number of indicators in the i-th indicator layer; F ij is the quantitative value of the jth indicator in the i-th indicator layer; w ij is the weight of the jth indicator in the ith indicator layer relative to the indicator layer; F is the comprehensive score of the pipeline operation plan; k is the number of indicator layers of the pipeline operation plan; S406: Enter the evaluation scores of the startup plan information and the operation parameter information in the operation plan into the pipeline operation plan database.

5. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The specific steps of S5 are: S501: calling the automatic response module based on the optimization algorithm, and selecting to use the model with known or unknown gas supply volume of the gas source according to the actual situation on site; S502: Under the condition of known gas supply volume, the gas supply volume, node distribution volume, and compression performance parameters are combined to solve the optimization model with the lowest operating energy consumption as the optimization goal, and obtain the optimal pipeline operation plan. The pipeline operation plan includes the operation mode of the compressor station, the number of compressors in operation, the inlet and outlet pressures, the compressor speed, and the single unit power; S503: When the gas supply volume is unknown, the gas supply volume of the gas source is changed from a known quantity to an optimization variable. The gas supply volume, node distribution volume, and compression performance parameters are combined to solve the optimization model with the lowest operating energy consumption as the optimization goal, and the optimal pipeline operation plan is obtained. The pipeline operation plan includes the gas supply volume of the gas source, the operation mode of the compressor station, the number of compressors in operation, the inlet and outlet pressures, the compressor speed, and the single-unit power.

6. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The objective function expression of the pipeline operation optimization model under the condition of known gas source supply volume is: In the formula, f is the energy consumption cost of boosting gas at the compressor station; is the total number of compressor stations along the pipeline; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; δ k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor; W k,l is the power of the lth compressor of the kth compressor station; t l The working time of the compressor of the first compressor station; The gas flow constraint is: In the formula, is the flow into node i; is the outflow of node i; Q i,j is the flow rate from the pipe segment j connected to the node i into the node; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum demand flow of demand node d; Q d is the demand flow of demand node d; The pipeline compressor station constraints are: Where P j is the pressure of the jth pipe section; P d is the demand node pressure; is the minimum delivery pressure of the demand node; N cs is the number of compressor stations put into operation along the pipeline; is the total number of compressor stations along the pipeline; The compressor constraints are: In the formula, is the total number of compressors in the first compressor station; r k,l is the speed of the kth compressor in the lth compressor station; is the minimum speed allowed for the kth compressor in the lth compressor station; is the maximum speed allowed for the kth compressor in the lth compressor station; Q k,l is the flow rate of the kth compressor in the lth compressor station; is the surge flow rate of the kth compressor in the lth compressor station; is the stagnation flow of the kth compressor in the lth compressor station; ε k,l is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio allowed for the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station; W is the maximum outlet pressure allowed by the kth compressor in the lth compressor station; k,l is the power of the kth compressor in the lth compressor station; is the minimum power allowed for the kth compressor in the lth compressor station; It is the maximum power allowed for the kth compressor in the lth compressor station.

7. A natural gas pipeline operation plan automatic response method as claimed in claim 1, characterized in that: The objective function expression of the pipeline operation optimization model under the condition of unknown gas source supply volume is: In the formula, f is the energy consumption cost of boosting gas at the compressor station; is the total number of compressor stations along the pipeline; S l is the variable of compressor station operation, S l = 0, indicating that the lth compressor station is not in operation, S l =1, it means the lth compressor station is in normal operation; δ k,l is the number of compressors in operation in the kth compressor station; E l is the energy price of the compressor; W k,l is the power of the lth compressor of the kth compressor station; t l The working time of the compressor of the first compressor station; The gas supply volume constraint is: In the formula, Q s is the supply flow rate of gas source s; is the minimum supply flow rate of gas source s; is the maximum supply flow of gas source s; The gas flow constraint is: In the formula, is the flow into node i; is the outflow of node i; Q i,j is the flow rate from the pipe segment j connected to the node i into the node; β ij is the direction variable, -1 indicates outflow node, 1 indicates inflow node; is the minimum demand flow of demand node d; Q d is the demand flow of demand node d; The pipeline compressor station constraints are: Where P j is the pressure of the jth pipe section; P d is the demand node pressure; is the minimum delivery pressure of the demand node; N cs is the number of compressor stations put into operation along the pipeline; is the total number of compressor stations along the pipeline; The compressor constraints are: In the formula, is the total number of compressors in the first compressor station; r k,l is the speed of the kth compressor in the lth compressor station; is the minimum speed allowed for the kth compressor in the lth compressor station; is the maximum speed allowed for the kth compressor in the lth compressor station; Q k,l is the flow rate of the kth compressor in the lth compressor station; is the surge flow rate of the kth compressor in the lth compressor station; is the stagnant flow of the kth compressor in the lth compressor station; ε k,l is the pressure ratio of the kth compressor in the lth compressor station; is the minimum pressure ratio allowed for the kth compressor in the lth compressor station; is the maximum pressure ratio allowed for the kth compressor in the lth compressor station; is the outlet pressure of the kth compressor in the lth compressor station; W is the maximum outlet pressure allowed by the kth compressor in the lth compressor station; k,l is the power of the kth compressor in the lth compressor station; is the minimum power allowed for the kth compressor in the lth compressor station; It is the maximum power allowed for the kth compressor in the lth compressor station.

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