A dynamic calculation and optimization method and system for a pipeline gas recovery process

Abstract

The application discloses a kind of dynamic calculation and optimization method and system of pipeline gas recovery process, applied to pipeline residual gas recovery technical field.The method comprises the following steps: obtaining compressor rated inlet pressure, rated pressure-increasing scale, pipeline start-stop pressure, target recovery gas amount and segmentation number;Pressure distribution sequence is generated, and the total volume of pipeline and the volume of gas at each pressure point in standard state are calculated;According to the dynamic correction of compressor processing capacity according to the change of inlet pressure, the recovery gas amount, the theoretical recovery time, the cumulative recovery gas amount and the recovery rate are calculated according to the pressure section;Further output pressure-time, cumulative gas amount-time and recovery rate-time curve, and give the optimization suggestion of recovery end point, compressor configuration and operation strategy.The application can reflect the processing capacity attenuation characteristics in later stage of recovery, improve the accuracy of recovery scheme design, operation control and economic evaluation.

Description

Technical Field

[0001] This invention relates to the field of pipeline residual gas recovery technology, and more specifically to a dynamic calculation and optimization method and system for pipeline gas recovery processes. Background Technology

[0002] At distribution stations or city gate stations of long-distance natural gas pipelines, throttling valves are commonly used to directly reduce the pressure of incoming high-pressure gas to meet the pressure requirements of downstream users or urban pipeline networks. This process is a typical irreversible throttling effect thermodynamically, resulting in a significant amount of high-quality pressure energy being irreversibly converted into low-grade heat energy, which is then dissipated through methods such as air cooling. For high-pressure, high-flow-rate pipeline systems, this continuous energy loss accumulates to a considerable amount, constituting a long-neglected hidden cost in pipeline operation and directly impacting the operational efficiency and economic benefits of the entire industry chain.

[0003] In existing recovery processes, venting or low-pressure emission modes carry inherent safety and environmental risks. During pressure regulation or maintenance, to ensure safety, it is often necessary to release some pipeline gas directly into the atmosphere. This not only results in direct energy waste, but more importantly, methane, the main component of natural gas, is a potent greenhouse gas with a greenhouse effect potential far exceeding that of carbon dioxide. Even trace but continuous escape emissions pose a potential threat to the regional atmospheric environment. Simultaneously, toxic and harmful components such as hydrogen sulfide that may be present in natural gas, if not properly handled under venting or low-pressure conditions, can directly threaten the safety of on-site personnel and the surrounding ecological environment. The industry's intelligent and refined operation places new demands on technological equipment. With the deepening of IoT, big data technology, and the concept of smart pipeline networks, traditional operation models relying on manual experience, qualitative judgment, and extensive management are no longer suitable for the safe, efficient, and reliable operation requirements of modern energy infrastructure. The market urgently needs technological equipment that can integrate pressure energy recovery, gas pressurization, online monitoring, and intelligent control. This type of equipment not only needs to address the question of whether it can be recycled, but also needs to answer quantitative questions such as how much can be recycled, at what speed, and what the economic benefits are through precise design calculations and simulations. This will provide a scientific basis for investment decisions, operational optimization, and risk management. Therefore, how to provide a dynamic calculation and optimization method and system for the pipeline gas recovery process is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a dynamic calculation and optimization method and system for pipeline gas recovery process, in order to solve the problem that the estimation of recovery time, recovery rate and equipment configuration caused by the use of static compressor processing capacity in the prior art is inaccurate.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A dynamic calculation and optimization method for a pipeline gas recovery process includes the following steps: Obtain the compressor unit's rated parameters and pipeline recovery parameters. The compressor unit's rated parameters include the rated inlet pressure. Rated outlet pressure and rated boost capacity Pipeline recovery parameters include the initial upper limit pressure of the pipeline for recovery. , Recovery end pipeline lower limit pressure Target total gas recovery volume Pressure segment number and atmospheric pressure absolute value compensation constant ; Based on the initial upper limit pressure of the recovery pipeline , Recovery end pipeline lower limit pressure and pressure segment number , generate from Start decreasing to Pressure distribution sequence ; Based on the target total gas recovery volume and and Calculate the equivalent total volume of the pipeline to be recovered based on the pressure difference between them. ; For pressure distribution sequence Calculate the volume of gas in the pipeline under standard conditions at each pressure point. And determine the segmented recovery gas volume between adjacent pressure points. ; For each pressure range, based on the rated inlet pressure Determine the dynamic boosting capacity of the compressor unit Dynamic boosting scale With rated inlet pressure The decrease is due to the reduction; Based on the segmented recovery gas volume of each pressure section and the corresponding dynamic boost scale Calculate the theoretical recovery time And accumulate the cumulative recovery time. Cumulative gas recovery volume and recovery rate ; Based on the cumulative calculation results, the system outputs the recovery pressure-time curve, the cumulative recovered gas volume-time curve, and the recovery rate-time curve, generating optimization results for adjusting the recovery endpoint pressure, the number of pressure segments, the compressor configuration, and the operating strategy.

[0006] Optionally, generate a pressure distribution sequence. Specifically, this involves calculating the step size of the pressure distribution sequence. Generate pressure distribution sequence ; Calculate the equivalent total volume of the pipeline to be recycled. Specifically: ,in Constants related to the conversion between pressure units, standard conditions, and volume units; Calculate the volume of gas in the pipeline under standard conditions. Specifically: Determine the segmented recovery gas volume between adjacent pressure points. Specifically: .

[0007] Optionally, the volume of gas in the pipeline under standard conditions. The real gas law is modified as follows: ; ; ; In the formula, For the first The absolute pressure at each pressure point For the first The pressure gauge pressure at each pressure point in the pipeline. For the first Gas volume converted to standard conditions at each pressure point. The equivalent volume of the pipeline to be recycled. The standard compressibility factor. Standard temperature For the first The compressibility factor at each pressure point For the first Gas temperature at each pressure point For the first Standard state pressure at each pressure point, and represents the dimensionless parameters of the state equation.

[0008] Optional, calculate the theoretical recovery time. Specifically: Calculate the cumulative recovery time Cumulative gas recovery volume and recovery rate Specifically: , , .

[0009] Optionally, determine the dynamic boosting scale of the compressor unit. Specifically: The compressor unit's processing capacity is dynamically adjusted according to changes in inlet pressure.

[0010] Optional, dynamic boost scale A comprehensive correction is made based on inlet temperature, gas compressibility factor, volumetric efficiency, load factor, and mechanical efficiency, specifically: ; In the formula, This is the revised dynamic boost level. The number of compressors operating in parallel. The rated processing capacity of a single compressor. For the first Absolute pressure at the inlet of each pressure segment The rated inlet absolute pressure, The rated inlet temperature, For the first Inlet temperature of each pressure section, The rated inlet compressibility factor, For the first Each pressure segment inlet compressibility factor For volumetric efficiency, This is the load adjustment coefficient. For mechanical transmission efficiency, This is a pressure correction index. This is the temperature correction index. This is the compression factor correction index.

[0011] Optionally, the optimization results are obtained by comparing different numbers of pressure segments, lower limit pressure of the recovery end pipeline, rated boost capacity of the compressor unit, or number of compressors in parallel. At least one of the following is used as the optimization objective: total recovery time, target recovery gas volume achievement rate, energy consumption reduction, or emission reduction. The multi-objective constraint function is as follows: ; In the formula, The vector of variables to be optimized. To comprehensively optimize the objective function, , , , and These are the weights for time, energy consumption, long tail, recycling rate, and constraint violation penalty function, respectively. Total recovery time, As a time normalization benchmark, Total energy consumption, As a benchmark for energy consumption normalization, To recover long-tail metrics in the later stages, As a long-tail normalization benchmark, This represents the actual recovery rate. For the target recovery rate, To constrain the penalty function for violations.

[0012] Optionally, when the boost pressure is obtained through dynamic calculation If the pressure drops below the preset boost threshold or the time required for a unit recovered gas volume exceeds the preset time threshold, a long-tail warning message for the later stage of recovery is generated, and the following options are output: stop recovery, switch compressors, add parallel compressors, or adjust the lower limit pressure. The suggestion.

[0013] Optionally, the detection unit collects pipeline pressure data in real time, and the real-time pressure is compared with the pressure distribution sequence. When the predicted pressure deviation exceeds the preset pressure threshold, the boosting scale, theoretical recovery time, and cumulative recovery rate are recalculated, and the optimization results are updated.

[0014] A dynamic calculation and optimization system for a pipeline gas recovery process, applying the aforementioned dynamic calculation and optimization method for a pipeline gas recovery process, includes: The input parameter acquisition module is used to acquire the rated parameters of the compressor unit and the pipeline recovery parameters; The pressure distribution calculation module is connected to the input parameter acquisition module and generates a pressure distribution sequence based on the upper limit pressure of the initial recovery pipeline and the lower limit pressure of the recovery pipeline. The total pipeline volume calculation module, connected to the pressure distribution calculation module, is used to calculate the equivalent total pipeline volume of the pipeline to be recovered, the volume at each pressure point under standard conditions, and the segmented recovery gas volume. The dynamic pressurization scale calculation module is connected to the total pipeline volume calculation module and is used to determine the dynamic pressurization scale of each pressure segment. The segmented recovery process simulation module is connected to the dynamic boosting scale calculation module, and is used to calculate the theoretical recovery time based on the segmented recovery gas volume and the dynamic boosting scale. The cumulative calculation and efficiency evaluation module is connected to the segmented recovery process simulation module. It is used to calculate the cumulative recovery time, cumulative recovered gas volume and recovery rate, and generate optimization results, long-tail warning in the later stage of recovery and optimization suggestions. The results output module is connected to the input parameter acquisition module and the cumulative calculation and efficiency evaluation module. It is used to output the recovery pressure-time curve, the cumulative recovered gas volume-time curve, the recovery rate-time curve, and optimization suggestions.

[0015] As can be seen from the above technical solution, compared with the prior art, the present invention provides a dynamic calculation and optimization method and system for pipeline gas recovery process, which has the following beneficial effects: 1. Based on the actual working condition of continuous decrease in inlet pressure during pipeline recycling, this invention establishes a calculation model for the compressor boosting scale to be dynamically corrected as the inlet pressure changes. This model can reflect the changing law of gradual decay of compressor suction capacity, processing capacity and effective recycling efficiency caused by the decrease in inlet pressure. It avoids the estimation deviation of recycling time and equipment selection error caused by simply treating the compressor boosting scale as a constant value in traditional methods, thereby improving the authenticity and engineering applicability of the calculation results of the recycling process. 2. This invention simulates the pipeline gas recovery process in segments according to pressure ranges, calculating the standard gas volume, segmented recovered gas volume, theoretical recovery time, cumulative recovered gas volume, and cumulative recovery rate for each pressure range. It also generates recovery pressure-time curves, cumulative recovered gas volume-time curves, and recovery rate-time curves, transforming the pipeline residual gas recovery process, which previously relied on experience-based judgment, into a quantifiable, traceable, and comparable dynamic calculation process. Through these curve results, operators can intuitively identify the inefficient range in the later stages of recovery where the recovered gas volume per unit time decreases significantly due to lower inlet pressure, providing a basis for determining whether to continue recovery or terminate it prematurely. 3. This invention can provide a quantitative optimization basis for the design of pipeline gas recovery schemes. By changing parameters such as the recovery endpoint pressure, the number of pressure segments, the compressor's rated inlet pressure, rated outlet pressure, rated boosting scale, the number of parallel compressors, and the operating combination mode, the system can quickly compare the total recovery time, total recovered gas volume, recovery rate, and compressor operating load changes under different schemes. This helps to determine the optimal recovery endpoint pressure, equipment specifications, and operating strategies, reducing investment waste caused by oversized equipment configuration and avoiding problems such as low recovery efficiency or excessively long recovery cycles due to insufficient equipment capacity. 4. This invention can improve the safety and environmental protection of pipeline gas recovery operations. By dynamically simulating and assessing the residual gas recovery process in advance, it can reduce the situation of blind venting, repeated debugging and reliance on manual experience in operation, reduce energy waste, greenhouse gas emissions and the risk of diffusion of flammable, toxic and harmful gases caused by direct emission of natural gas or industrial gas, and help improve the intrinsic safety level in operation scenarios such as maintenance, shutdown, replacement and pressure regulation. 5. This invention has good applicability and scalability. Its calculation method is not only applicable to residual gas recovery in scenarios such as long-distance natural gas pipelines, distribution stations, and city gate stations, but also to systems with pressure reduction recovery characteristics, such as industrial gas pipelines, gas storage facilities, and station process pipelines. By adjusting the input parameters and calculation constants, it can be adapted to different gas media, different pipeline volumes, different pressure levels, and different compressor configurations, and has strong engineering application value. 6. This invention helps to realize the digital and intelligent management of pipeline gas recovery process. By integrating input parameter acquisition, pressure distribution calculation, compressor boosting scale dynamic calculation, segmented recovery simulation, cumulative efficiency evaluation and result output into a unified process, it can provide a foundation for subsequent access to online pressure sensors, flow meters, compressor operation data and station control systems, enabling the pipeline gas recovery process to develop from static estimation to dynamic simulation, online monitoring and intelligent optimization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a flowchart of the dynamic calculation and optimization method for the pipeline gas recovery process of the present invention; Figure 2 This is a flowchart of the input parameter acquisition and pressure distribution model generation process of the present invention; Figure 3 This is a schematic diagram of the dynamic calculation and optimization system for the pipeline gas recovery process of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention discloses a dynamic calculation and optimization method for a pipeline gas recovery process, such as... Figure 1 and Figure 2 As shown, it includes the following steps: Obtain the compressor unit's rated parameters and pipeline recovery parameters. The compressor unit's rated parameters include the rated inlet pressure. Rated outlet pressure and rated boost capacity Pipeline recovery parameters include the initial upper limit pressure of the pipeline for recovery. , Recovery end pipeline lower limit pressure Target total gas recovery volume Pressure segment number and atmospheric pressure absolute value compensation constant ; Based on the initial upper limit pressure of the recovery pipeline , Recovery end pipeline lower limit pressure and pressure segment number , generate from Start decreasing to Pressure distribution sequence ; Based on the target total gas recovery volume and and Calculate the equivalent total volume of the pipeline to be recovered based on the pressure difference between them. ; For pressure distribution sequence Calculate the volume of gas in the pipeline under standard conditions at each pressure point. And determine the segmented recovery gas volume between adjacent pressure points. ; For each pressure range, based on the rated inlet pressure Determine the dynamic boosting capacity of the compressor unit Dynamic boosting scale With rated inlet pressure The decrease is due to the reduction; Based on the segmented recovery gas volume of each pressure section and the corresponding dynamic boost scale Calculate the theoretical recovery time And accumulate the cumulative recovery time. Cumulative gas recovery volume and recovery rate ; Based on the cumulative calculation results, the system outputs the recovery pressure-time curve, the cumulative recovered gas volume-time curve, and the recovery rate-time curve, generating optimization results for adjusting the recovery endpoint pressure, the number of pressure segments, the compressor configuration, and the operating strategy.

[0020] Furthermore, a pressure distribution sequence is generated. Specifically, this involves calculating the step size of the pressure distribution sequence. Generate pressure distribution sequence ; Calculate the equivalent total volume of the pipeline to be recycled. Specifically: ,in Constants related to the conversion between pressure units, standard conditions, and volume units; Calculate the volume of gas in the pipeline under standard conditions. Specifically: Determine the segmented recovery gas volume between adjacent pressure points. Specifically: .

[0021] In this embodiment of the invention, a real gas correction model, a compressor dynamic capability model, an energy consumption constraint model, and an online deviation correction model can also be used for correction. The above models can be used as a supplement to the pressure segment calculation without changing the original pressure distribution, segmented recovery, and cumulative evaluation process.

[0022] Furthermore, the volume of gas inside the pipeline under standard conditions The real gas law is modified as follows: ; ; ; In the formula, For the first The absolute pressure at each pressure point For the first The pressure gauge pressure at each pressure point in the pipeline. For the first Gas volume converted to standard conditions at each pressure point. The equivalent volume of the pipeline to be recycled. The standard compressibility factor. Standard temperature For the first The compressibility factor at each pressure point For the first Gas temperature at each pressure point For the first Standard state pressure at each pressure point, and represents the dimensionless parameters of the state equation.

[0023] In this embodiment of the invention, the gas compressibility factor It can be obtained through table lookup, state equations, or online fitting; when rapid engineering estimation is required, the following second-order modified model can be used: ; In the formula, , , , , These are correction factors obtained from gas properties or on-site calibration; This represents the volume fraction of carbon dioxide. For nitrogen gas, the integral fraction can be used; for other industrial gases, it can also be... and Replace with the volume fraction of the corresponding component.

[0024] For natural gas or multi-component industrial gases containing carbon dioxide, nitrogen, hydrogen, etc., the dimensionless parameters of the equation of state are calculated based on the composition of the mixed gas: ; ; ; ; In the formula, The gas constant is... For the first Parameters of the gas attraction term at each pressure point; For the first Parameters of the repulsion term of the mixed gas at each pressure point; The quantity of gas components; and The first The first pressure point Class and First Mole fraction of the class of components; and The first Class and First The pure component attraction term parameters of the class of components; For the first Pure component exclusion term parameters of class components; For the first Class and First Binary interaction coefficients between class components For the first Critical temperature of the component class; For the first Critical pressure of class components; This is a temperature correction factor; For the first Component eccentricity factor.

[0025] Furthermore, the theoretical recovery time is calculated. Specifically: Calculate the cumulative recovery time Cumulative gas recovery volume and recovery rate Specifically: , , .

[0026] Furthermore, determine the dynamic boosting scale of the compressor unit. Specifically: The compressor unit's processing capacity is dynamically adjusted according to changes in inlet pressure.

[0027] Furthermore, the dynamic boosting scale A comprehensive correction is made based on inlet temperature, gas compressibility factor, volumetric efficiency, load factor, and mechanical efficiency, specifically: ; In the formula, This is the revised dynamic boost level. The number of compressors operating in parallel. The rated processing capacity of a single compressor. For the first Absolute pressure at the inlet of each pressure segment The rated inlet absolute pressure, The rated inlet temperature, For the first Inlet temperature of each pressure section, The rated inlet compressibility factor, For the first Each pressure segment inlet compressibility factor For volumetric efficiency, This is the load adjustment coefficient. For mechanical transmission efficiency, This is a pressure correction index. This is the temperature correction index. This is the compression factor correction index.

[0028] In this embodiment of the invention, when a reciprocating compressor or a compressor with a significant clearance volume effect is used, the volumetric efficiency can be corrected by the following formula: ; In the formula, This is the compressor clearance coefficient. compressor outlet absolute pressure, It is a variable compression index.

[0029] If the first The average pressure boost and theoretical recovery time are calculated by taking the weighted average of the processing capacities at the beginning and end of each pressure segment: ; ; In the formula, For the first Average boost pressure across each pressure range; For the first The dynamic boost pressure scale corresponding to each pressure point; This is the average weighting coefficient, with a value range of 0 ≤ ≤1; For the first The theoretical recovery time for each pressure segment.

[0030] Furthermore, the optimization results are obtained by comparing different numbers of pressure segments, lower limit pressure of the recovery end pipeline, rated boost capacity of the compressor unit, or number of compressors in parallel. At least one of the following is used as the optimization objective: total recovery time, target recovery gas volume achievement rate, energy consumption reduction, or emission reduction. The multi-objective constraint function is as follows: ; In the formula, The vector of variables to be optimized. To comprehensively optimize the objective function, , , , and These are the weights for time, energy consumption, long tail, recycling rate, and constraint violation penalty function, respectively. Total recovery time, As a time normalization benchmark, Total energy consumption, As a benchmark for energy consumption normalization, To recover long-tail metrics in the later stages, As a long-tail normalization benchmark, This represents the actual recovery rate. For the target recovery rate, To constrain the penalty function for violations.

[0031] In this embodiment of the invention, in order to evaluate energy consumption simultaneously during the scheme design phase, the first Compression power of each pressure range It can be estimated based on polyvariable compression relations: ; In the formula, The adiabatic index of the gas. For the first Molar flow rate of each pressure segment For the first The variable efficiency of each pressure section. The segmented energy consumption, total recovery time, and total energy consumption can be expressed as: ; ; For the first Energy consumption of each pressure zone; Total recovery time; The number of pressure segments.

[0032] Long-tail indicators in the later stages of recovery It can be calculated using the following formula: ; The larger the value, the more time is required for a unit volume of gas in the later stage compared to the first stage; This is the theoretical recovery time for the first pressure stage; This refers to the segmented recovery gas volume for the first pressure stage.

[0033] The optimization process should meet the following constraints: ; in, The minimum permissible recovery endpoint pressure; The actual selected endpoint pressure for recovery; To recover the initial upper limit pressure of the pipeline; The minimum allowable dynamic boost level; This refers to the compressor's rated power. For the first Cumulative recovery rate of each pressure zone; The target recovery rate.

[0034] Furthermore, when the boost pressure is obtained through dynamic calculation... If the pressure drops below the preset boost threshold or the time required for a unit recovered gas volume exceeds the preset time threshold, a long-tail warning message for the later stage of recovery is generated, and the following options are output: stop recovery, switch compressors, add parallel compressors, or adjust the lower limit pressure. The suggestion.

[0035] Furthermore, the detection unit collects pipeline pressure data in real time, and the real-time pressure is compared with the pressure distribution sequence. When the predicted pressure deviation exceeds the preset pressure threshold, the boosting scale, theoretical recovery time, and cumulative recovery rate are recalculated, and the optimization results are updated.

[0036] In this embodiment of the invention, when a pressure sensor and a flow meter are connected to the system, the predictive processing capability can be corrected online using measured data. ; In the formula, Predict the boost pressure for the i-th pressure segment after the r-th correction; This is the predicted boost pressure after the last correction; This represents the measured pressure boosting capacity of the i-th pressure segment; This is a smoothing coefficient, with a value range of 0 ≤ ≤1; r represents the number of online calibrations.

[0037] Based on the corrected boost level, the pressure prediction deviation can be further obtained and a recalculation can be triggered: ; ; In the formula, The pressure prediction deviation at the i-th pressure point; The measured pressure at the i-th pressure point; The predicted pressure at the i-th pressure point; This represents the predicted pressure at the (i+1)th pressure point. When the preset pressure deviation threshold is exceeded, the calculation / control unit recalculates the dynamic pressurization scale, theoretical recovery time, energy consumption, and recovery rate of the subsequent pressure segment.

[0038] When evaluating environmental benefits, the equivalent emission reduction corresponding to the recovered gas volume can be estimated using the following formula: ; ; In the formula, The recovery mass of the g-th gas component; The density of the gas mixture under standard conditions; denoted as the volume fraction of the g-th gas component; This is the correction factor for converting the volume fraction of gas component g to the mass fraction. This represents the carbon dioxide equivalent emission reduction; G represents the number of gaseous components involved in the calculation. denoted as the global warming potential coefficient of the g-th gas component.

[0039] Through the above-mentioned modified model, this invention can not only output the recovery time and recovery rate, but also simultaneously output the dynamic boosting scale change, unit gas volume recovery time, segmented energy consumption, total energy consumption, long-tail risk and emission reduction benefits, thereby providing a more complete quantitative basis for the selection of recovery endpoint, compressor configuration and operation strategy.

[0040] In one embodiment of the present invention, a natural gas pipeline shutdown recovery project is taken as an example. 1. Calculate the pressure step size: ; Generate pressure distribution sequence ,from Starting at MPag, decreasing in increments of 0.445 MPag, until... MPag. For example: , , , ..., ; 2. Calculate the total volume of the pipeline: Use the formula: Substitute the values: Verification: Initial standard volume End of standard condition volume. Recoverable gas volume Consistent with the input target; 3. Dynamically calculate the compressor boosting capacity at each pressure point: based on the formula... .exist At MPag ,exist At MPag ,exist At MPag ; The compressor's actual operating capacity decreases significantly as the inlet pressure drops, from an initial 1264 Nm³ / h to only 28 Nm³ / h. This is a key dynamic characteristic that traditional static calculations overlook.

[0041] Segmented simulation of the recycling process (taking segments 1 and 2 as examples): Paragraph 1 (Pressure from) MPag decreased to (MPag). This section requires the recovery of gas volume. The average boost pressure in this section can be taken as... This period of collection time ; Paragraph 2 (Pressure from) MPag decreased to MPag): Recovered gas volume (Equal air volume in each segment, due to uniform pressure distribution), pressurization scale Recycling time

[0042] Cumulative calculation and recovery curve generation: The system automatically completes the above calculations for all 20 pressure segments. Cumulative recovery time: For example, when completing the first 10 segments (recovering approximately 50% of the gas volume), the cumulative time is... Minutes. Total time when all recycling is complete. Minutes. Cumulative recovery rate: ,when hour, when hour .

[0043] and Figure 1 Corresponding to the method described above, this embodiment of the invention also discloses a dynamic calculation and optimization system for a pipeline gas recovery process. Applying the aforementioned dynamic calculation and optimization method for a pipeline gas recovery process, as follows... Figure 3 As shown, it includes: The input parameter acquisition module is used to acquire the rated parameters of the compressor unit and the pipeline recovery parameters; The pressure distribution calculation module is connected to the input parameter acquisition module and generates a pressure distribution sequence based on the upper limit pressure of the initial recovery pipeline and the lower limit pressure of the recovery pipeline. The total pipeline volume calculation module, connected to the pressure distribution calculation module, is used to calculate the equivalent total pipeline volume of the pipeline to be recovered, the volume at each pressure point under standard conditions, and the segmented recovery gas volume. The dynamic pressurization scale calculation module is connected to the total pipeline volume calculation module and is used to determine the dynamic pressurization scale of each pressure segment. The segmented recovery process simulation module is connected to the dynamic boosting scale calculation module, and is used to calculate the theoretical recovery time based on the segmented recovery gas volume and the dynamic boosting scale. The cumulative calculation and efficiency evaluation module is connected to the segmented recovery process simulation module. It is used to calculate the cumulative recovery time, cumulative recovered gas volume and recovery rate, and generate optimization results, long-tail warning in the later stage of recovery and optimization suggestions. The results output module is connected to the input parameter acquisition module and the cumulative calculation and efficiency evaluation module. It is used to output the recovery pressure-time curve, the cumulative recovered gas volume-time curve, the recovery rate-time curve, and optimization suggestions.

[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0045] Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dynamic calculation and optimization method for a pipeline gas recovery process, characterized in that, Includes the following steps: Obtain the compressor unit's rated parameters and pipeline recovery parameters. The compressor unit's rated parameters include the rated inlet pressure. Rated outlet pressure and rated boost capacity Pipeline recovery parameters include the initial upper limit pressure of the pipeline for recovery. , Recovery end pipeline lower limit pressure Target total gas recovery volume Pressure segment number and atmospheric pressure absolute value compensation constant ; Based on the initial upper limit pressure of the recovery pipeline , Recovery end pipeline lower limit pressure and pressure segment number , generate from Start decreasing to pressure distribution sequence ; Based on the target total gas recovery volume and and Calculate the equivalent total volume of the pipeline to be recovered based on the pressure difference between them. ; For pressure distribution sequence Calculate the volume of gas in the pipeline under standard conditions at each pressure point. And determine the segmented recovery gas volume between adjacent pressure points. ; For each pressure range, based on the rated inlet pressure Determine the dynamic boosting capacity of the compressor unit Dynamic boosting scale With rated inlet pressure The decrease is due to the reduction; Based on the segmented recovery gas volume of each pressure section and the corresponding dynamic boost scale Calculate the theoretical recovery time And accumulate the cumulative recovery time. Cumulative gas recovery volume and recovery rate ; Based on the cumulative calculation results, the system outputs the recovery pressure-time curve, the cumulative recovered gas volume-time curve, and the recovery rate-time curve, generating optimization results for adjusting the recovery endpoint pressure, the number of pressure segments, the compressor configuration, and the operating strategy.

2. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, Generate pressure distribution sequence Specifically, this involves calculating the step size of the pressure distribution sequence. Generate pressure distribution sequence ; Calculate the equivalent total volume of the pipeline to be recycled. Specifically: ,in Constants related to the conversion between pressure units, standard conditions, and volume units; Calculate the volume of gas in the pipeline under standard conditions. Specifically: Determine the segmented recovery gas volume between adjacent pressure points. Specifically: .

3. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, The volume of gas inside the pipeline under standard conditions The real gas law is modified as follows: ； ； ； In the formula, For the first The absolute pressure at each pressure point For the first The pressure gauge pressure at each pressure point in the pipeline. For the first Gas volume converted to standard conditions at each pressure point. The equivalent volume of the pipeline to be recycled. The standard compressibility factor. Standard temperature For the first The compressibility factor at each pressure point For the first Gas temperature at each pressure point For the first Standard state pressure at each pressure point, and represents the dimensionless parameters of the state equation.

4. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, Calculate the theoretical recovery time Specifically: Calculate the cumulative recovery time Cumulative gas recovery volume and recovery rate Specifically: , , .

5. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, Determine the dynamic boosting capacity of the compressor unit Specifically: The compressor unit's processing capacity is dynamically adjusted according to changes in inlet pressure.

6. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 5, characterized in that, Dynamic boost scale A comprehensive correction is made based on inlet temperature, gas compressibility factor, volumetric efficiency, load factor, and mechanical efficiency, specifically: ； In the formula, This is the revised dynamic boost level. The number of compressors operating in parallel. The rated processing capacity of a single compressor. For the first Absolute pressure at the inlet of each pressure segment The rated inlet absolute pressure, The rated inlet temperature, For the first Inlet temperature of each pressure section, The rated inlet compressibility factor, For the first Each pressure segment inlet compressibility factor For volumetric efficiency, This is the load adjustment coefficient. For mechanical transmission efficiency, This is a pressure correction index. This is the temperature correction index. This is the compression factor correction index.

7. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, The optimization results are obtained by comparing different numbers of pressure segments, lower limit pressure of the recovery end pipeline, rated boost capacity of the compressor unit, or number of compressors in parallel. At least one of the following is used as the optimization objective: total recovery time, target recovery gas volume achievement rate, energy consumption reduction, or emission reduction. The multi-objective constraint function is as follows: ； In the formula, The vector of variables to be optimized. To comprehensively optimize the objective function, , , , and These are the weights for time, energy consumption, long tail, recycling rate, and constraint violation penalty function, respectively. Total recovery time, As a time normalization benchmark, Total energy consumption, As a benchmark for energy consumption normalization, To recover long-tail metrics in the later stages, As a long-tail normalization benchmark, This represents the actual recovery rate. For the target recovery rate, To constrain the penalty function for violations.

8. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, When the boost pressure is obtained through dynamic calculation If the pressure drops below the preset boost threshold or the time required for a unit recovered gas volume exceeds the preset time threshold, a long-tail warning message for the later stage of recovery is generated, and the following options are output: stop recovery, switch compressors, add parallel compressors, or adjust the lower limit pressure. The suggestion.

9. The dynamic calculation and optimization method for a pipeline gas recovery process according to claim 1, characterized in that, The detection unit collects pipeline pressure data in real time, and the real-time pressure is compared with the pressure distribution sequence. When the predicted pressure deviation exceeds the preset pressure threshold, the boosting scale, theoretical recovery time, and cumulative recovery rate are recalculated, and the optimization results are updated.

10. A dynamic calculation and optimization system for a pipeline gas recovery process, characterized in that, The dynamic calculation and optimization method for a pipeline gas recovery process according to any one of claims 1-9 includes: The input parameter acquisition module is used to acquire the rated parameters of the compressor unit and the pipeline recovery parameters; The pressure distribution calculation module is connected to the input parameter acquisition module and generates a pressure distribution sequence based on the upper limit pressure of the initial recovery pipeline and the lower limit pressure of the recovery pipeline. The total pipeline volume calculation module, connected to the pressure distribution calculation module, is used to calculate the equivalent total pipeline volume of the pipeline to be recovered, the volume at each pressure point under standard conditions, and the segmented recovery gas volume. The dynamic pressurization scale calculation module is connected to the total pipeline volume calculation module and is used to determine the dynamic pressurization scale of each pressure segment. The segmented recovery process simulation module is connected to the dynamic boosting scale calculation module, and is used to calculate the theoretical recovery time based on the segmented recovery gas volume and the dynamic boosting scale. The cumulative calculation and efficiency evaluation module is connected to the segmented recovery process simulation module. It is used to calculate the cumulative recovery time, cumulative recovered gas volume and recovery rate, and generate optimization results, long-tail warning in the later stage of recovery and optimization suggestions. The results output module is connected to the input parameter acquisition module and the cumulative calculation and efficiency evaluation module. It is used to output the recovery pressure-time curve, the cumulative recovered gas volume-time curve, the recovery rate-time curve, and optimization suggestions.

Images