A compressed air energy storage gas storage reservoir parallel wellhead dispatching control method and system

Abstract

The application discloses a compressed air energy storage gas storage library parallel well mouth scheduling control method and system, belongs to the technical field of compressed air energy storage system, the scheduling control method, including: obtaining the gas storage library side pressure, the gas storage library side temperature and the pipeline flow; the pipeline real-time flow rate is calculated; the pipeline real-time flow rate is compared with the target flow rate, and the target PID control signal is generated to the pipeline real-time flow rate reaches the target flow rate; the opening of the regulating valve in the compressed gas pipeline is controlled to realize the regulation of the pipeline flow size; the execution part in the scheduling control system includes the gas injection regulating valve group and the gas production regulating valve group, the detection part includes the pressure measuring point sensor, the temperature measuring point sensor and the flowmeter, and the control part includes the gas injection algorithm unit and the gas production algorithm unit. The application can effectively solve the technical problem of uneven distribution of injection and production gas volume of parallel well mouth, and avoid the risk of injection and production pipe well structure damage caused by the air flow rate in part of injection and production pipe exceeding the erosion flow rate.

Description

Technical Field

[0001] This invention relates to a scheduling and control method and system for parallel wellheads of compressed air energy storage gas storage tanks, belonging to the technical field of compressed air energy storage systems. Background Technology

[0002] Compressed air energy storage technology, as a new type of large-scale energy storage technology, has advantages such as large energy storage capacity, high operating efficiency, strong safety and reliability, and environmental friendliness. It can effectively solve the intermittency and volatility problems of new energy power generation (such as wind power and photovoltaic), realize efficient storage and rational allocation of electrical energy, and has broad application prospects in the fields of power system peak shaving, frequency regulation, and backup power. It is one of the core energy storage technologies supporting the construction of new power systems.

[0003] Currently, commonly used gas storage facilities in compressed air energy storage systems mainly include salt cavern gas storage, rock cavern gas storage, and underground aquifer gas storage. Among them, salt cavern gas storage has become the preferred gas storage carrier for large-capacity compressed air energy storage systems due to its good sealing performance, short construction period, large capacity, relatively low cost, and small environmental impact. It is especially suitable for long-term storage and dispatch of large-scale electrical energy.

[0004] As compressed air energy storage technology develops towards larger capacity and higher parameters, large-capacity compressed air energy storage units typically require multiple injection and production wells, employing multiple injection and production pipes operating in parallel to meet the demands of large-scale gas injection and production, thereby improving the flexibility and reliability of system operation. However, due to the differences in the wellhead locations of the multiple injection and production wells, the pipeline resistance and flow characteristics of each parallel injection and production pipe inherently differ. This can easily lead to uneven distribution of injected and produced gas during simultaneous operation of multiple pipes.

[0005] When the injection and production gas volumes are unevenly distributed, some injection and production pipes may experience excessive air intake, causing the air velocity inside the pipe to exceed its allowable erosion velocity. Under long-term operation, the high-speed airflow will continuously erode the inner wall of the injection and production pipe, causing wear, thinning, and even structural damage such as cracks and leaks. This seriously undermines the stability of the wellbore operation, which not only affects the normal injection and production operation of the compressed air energy storage system, but may also lead to a decrease in the sealing performance of the gas storage tank, a reduction in energy storage efficiency, and even safety hazards, thus adversely affecting the long-term stable and safe operation of the entire compressed air energy storage system.

[0006] Furthermore, there is currently a lack of effective means to detect the flow state of the medium within the injection and production pipes, making it impossible to obtain real-time and accurate air velocity data within each parallel injection and production pipe. Consequently, it is impossible to reasonably control the flow velocity within the pipes, making it difficult to prevent erosion damage caused by excessive flow velocity at the source. This further exacerbates the safety risks and instability of parallel wellhead injection and production operations. Therefore, there is an urgent need to develop a scheduling and control system and operating strategy for gas storage parallel wellheads that can avoid the aforementioned safety risks and ensure stable system operation. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a scheduling and control method and system for parallel wellheads of compressed air energy storage gas storage tanks. This method and system can effectively solve the technical problem of uneven distribution of injection and production gas at parallel wellheads and avoid the risk of damage to the wellbore structure caused by the air velocity in some injection and production pipes exceeding the erosion velocity.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention discloses a scheduling and control method for parallel wellheads of compressed air energy storage gas storage facilities, comprising the following steps:

[0010] Obtain the pressure, temperature, and pipeline flow rate of the gas storage facility;

[0011] The real-time flow velocity in the pipeline is calculated based on the pressure and temperature of the gas storage side and the pipeline flow rate.

[0012] The real-time flow velocity in the pipeline is compared with the preset target flow velocity, and a PID control signal is generated with the real-time flow velocity in the pipeline reaching the target flow velocity as the objective.

[0013] The opening degree of the regulating valve in the compressed gas pipeline is controlled by the PID control signal to regulate the pipeline flow rate.

[0014] The real-time flow velocity in the pipeline, calculated based on the gas storage side pressure, gas storage side temperature, and pipeline flow rate, includes:

[0015] First, calculate the density of the compressed gas in the pipeline. The specific calculation formula is as follows:

[0016] (1);

[0017] in, This indicates the density of the compressed gas. Indicates the pressure on the gas storage side. Represents the specific gas constant. This indicates the temperature on the gas storage side;

[0018] Next, calculate the real-time flow velocity in the pipe. The specific calculation formula is as follows:

[0019] (2);

[0020] in, This indicates the real-time flow rate in the pipeline. Indicates pipeline flow rate, Indicates the outer diameter of the injection / production pipe. This indicates the wall thickness of the injection / production tube.

[0021] The formula for generating the PID control signal is:

[0022] (3);

[0023] in, For PID control signals, For proportional gain, This represents the deviation signal, specifically the difference between the target flow velocity and the real-time flow velocity in the pipeline. For integral gain, Historical traffic error For differential gain, Indicates the current moment.

[0024] If the pressure on the gas storage side is greater than the upper pressure alarm value or less than the lower pressure alarm value, the opening of the regulating valve in the control pipeline will be zero.

[0025] Secondly, this invention discloses a scheduling and control system for a parallel wellhead of a compressed air energy storage gas reservoir, comprising: a compressor, an air turbine, and a gas reservoir. The compressor and air turbine are connected to the gas reservoir via a compressed gas pipeline. An injection pipeline and a gas production pipeline are connected in parallel in the middle of the compressed gas pipeline. An injection regulating valve group and a production regulating valve group are respectively installed on the injection pipeline and the production pipeline. A pressure measuring sensor and a temperature measuring sensor are installed on the side of the compressed gas pipeline near the gas reservoir. A flow meter is installed on the compressed gas pipeline. The pressure measuring sensor, the temperature measuring sensor, and the flow meter are all electrically connected to the signal input terminals of the injection algorithm unit and the production algorithm unit. The signal output terminals of the injection algorithm unit and the production algorithm unit are respectively electrically connected to the injection regulating valve group and the production regulating valve group. The injection algorithm unit and the production algorithm unit are configured to execute the scheduling and control method for the parallel wellhead of the compressed air energy storage gas reservoir.

[0026] The flow meter includes a device-side bidirectional flow meter and a gas storage-side bidirectional flow meter. The device-side bidirectional flow meter is installed on the compressed gas pipeline near the compressor and air turbine. The gas storage-side bidirectional flow meter is installed on the compressed gas pipeline near the gas storage. The device-side bidirectional flow meter and the gas storage-side bidirectional flow meter are respectively connected to the signal input terminal of the flow selection module. The signal output terminal of the flow selection module is electrically connected to the gas injection algorithm unit and the gas sampling algorithm unit.

[0027] The gas injection regulating valve group includes a first isolation valve, a second isolation valve, and a gas injection regulating valve. The first isolation valve and the second isolation valve are located on both sides of the gas injection regulating valve, and the gas injection regulating valve is electrically connected to the gas injection algorithm unit.

[0028] The gas extraction regulating valve group includes a third isolation valve, a fourth isolation valve, and a gas extraction regulating valve. The third isolation valve and the fourth isolation valve are located on both sides of the gas extraction regulating valve, and the gas extraction regulating valve is electrically connected to the gas extraction algorithm unit.

[0029] Beneficial Effects: This invention provides a scheduling and control method and system for parallel wellheads of compressed air energy storage gas storage facilities. It compares the real-time flow velocity in the pipeline with a preset target flow velocity, generating a PID control signal based on the target flow velocity. The opening of the regulating valve in the compressed gas pipeline is controlled according to the PID control signal to adjust the pipeline flow rate. This proactive protection of the gas storage injection and production process at the control strategy level enables balanced control of the injection and production flow at each wellhead, effectively solving the technical problem of uneven gas distribution in each branch when multiple injection and production pipes are connected in parallel. It prevents local flow velocities from exceeding the material erosion threshold, thereby avoiding wellbore structural damage caused by erosion, reducing the risk of wellbore failure, and enhancing the system's adaptability to complex operating conditions. This provides crucial support for the continuous, efficient, and safe operation of compressed air energy storage power stations. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the scheduling and control method for parallel wellheads of a compressed air energy storage gas storage facility according to the present invention.

[0031] Figure 2 This is a schematic diagram of the scheduling and control system for a compressed air energy storage gas storage facility connected to parallel wellheads according to the present invention.

[0032] The reference numerals in the diagram are as follows: 110-Compressor; 120-Air turbine; 200-Gas storage tank; 301-Equipment-side bidirectional flow meter; 302-Gas storage tank bidirectional flow meter; 303-Pressure sensor; 304-Temperature sensor; 305-Flow selection module; 410-Injection algorithm unit; 420-Gas sampling algorithm unit; 601-First isolation valve; 602-Second isolation valve; 603-Third isolation valve; 604-Fourth isolation valve; 610-Injection regulating valve; 620-Gas sampling regulating valve. Detailed Implementation

[0033] The present invention will be further described below. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, this invention discloses a scheduling and control method for parallel wellheads of compressed air energy storage gas storage facilities, comprising the following steps:

[0036] Step 1: Obtain the pressure, temperature, and pipeline flow rate of the gas storage facility.

[0037] Step two involves calculating the real-time flow velocity in the pipeline based on the gas storage side pressure, gas storage side temperature, and pipeline flow rate, including:

[0038] First, calculate the density of the compressed gas in the pipeline. The specific calculation formula is as follows:

[0039] (1);

[0040] in, This indicates the density of the compressed gas. Indicates the pressure on the gas storage side. Represents the specific gas constant. This indicates the temperature on the gas storage side;

[0041] Next, calculate the real-time flow velocity in the pipe. The specific calculation formula is as follows:

[0042] (2);

[0043] in, This indicates the real-time flow rate in the pipeline. Indicates pipeline flow rate, Indicates the outer diameter of the injection / production pipe.

[0044] Based on the wellbore design requirements, the preferred values ​​are 273mm or 340mm. This indicates the wall thickness of the injection and production pipes, which is preferably selected from 11.5mm to 15mm based on the wellbore design conditions. If the pressure on the gas storage side is greater than the upper pressure alarm value or less than the lower pressure alarm value, the opening of the regulating valve in the pipeline will be directly controlled to zero.

[0045] Step 3: Compare the real-time flow velocity in the pipeline with the preset target flow velocity, and generate a PID control signal with the real-time flow velocity reaching the target flow velocity as the objective. The preset target flow velocity Vm is the upper limit of the medium flow velocity in the injection and extraction pipe, and a value of 10 m / s is preferred.

[0046] The formula for generating the PID control signal is:

[0047] (3);

[0048] in, For PID control signals, For proportional gain, This represents the deviation signal, specifically the difference between the target flow velocity and the real-time flow velocity in the pipeline. For integral gain, Historical traffic error For differential gain, Indicates the current moment.

[0049] Step four: Control the opening of the regulating valve in the compressed gas pipeline according to the PID control signal to adjust the pipeline flow rate.

[0050] This invention compares the real-time flow velocity in the pipeline with a preset target flow velocity, and generates a PID control signal with the real-time flow velocity reaching the target flow velocity as the objective. The opening of the regulating valve in the compressed gas pipeline is controlled according to the PID control signal to adjust the pipeline flow rate. This achieves active protection of the gas storage injection and production process from the control strategy level, and can realize balanced control of the injection and production flow at each wellhead, effectively solving the technical problem of uneven gas distribution in each branch when multiple injection and production pipelines are connected in parallel.

[0051] Example 2

[0052] like Figure 2 As shown, this invention discloses a scheduling and control system for a compressed air energy storage gas storage tank connected to a parallel wellhead, comprising: a compressor 110, an air turbine 120, and a gas storage tank 200. The compressor 110 and air turbine 120 are connected to the gas storage tank 200 via compressed gas pipelines, with an injection pipeline and a gas extraction pipeline connected in parallel in the middle of the compressed gas pipelines. The compressor draws in air from the atmospheric environment at 110 and compresses it to obtain high-pressure gas. The high-pressure gas is cooled by a cold source and then enters the gas storage tank 200 through the injection pipeline. The high-pressure gas stored in the gas storage tank 200 is heated by a heat source through the gas extraction pipeline and then entered into the turbine 120 for expansion and work before being discharged into the atmosphere.

[0053] The gas injection pipeline and the gas extraction pipeline are respectively equipped with a gas injection regulating valve group and a gas extraction regulating valve group. The gas injection regulating valve group includes a first isolation valve 601, a second isolation valve 602, and a gas injection regulating valve 610. The first isolation valve 601 and the second isolation valve 602 are located on opposite sides of the gas injection regulating valve 610, and the gas injection regulating valve 610 is electrically connected to the gas injection algorithm unit 410. The gas extraction regulating valve group includes a third isolation valve 603, a fourth isolation valve 604, and a gas extraction regulating valve 620. The third isolation valve 603 and the fourth isolation valve 604 are located on opposite sides of the gas extraction regulating valve 620, and the gas extraction regulating valve 620 is electrically connected to the gas extraction algorithm unit 420.

[0054] A pressure measuring sensor 303 and a temperature measuring sensor 304 are installed on the side of the compressed gas pipe near the gas storage tank 200. A flow meter is installed on the compressed gas pipe. The pressure measuring sensor 303, the temperature measuring sensor 304, and the flow meter are all electrically connected to the signal input terminals of the gas injection algorithm unit 410 and the gas production algorithm unit 420. The signal output terminals of the gas injection algorithm unit 410 and the gas production algorithm unit 420 are electrically connected to the gas injection regulating valve group and the gas production regulating valve group, respectively. The gas injection algorithm unit 410 and the gas production algorithm unit 420 are configured to execute the scheduling and control method of the parallel wellhead of the compressed air energy storage gas storage tank in Example 1.

[0055] The flow meters include a bidirectional flow meter 301 on the equipment side and a bidirectional flow meter 302 on the gas storage side. Both the equipment-side bidirectional flow meter 301 and the gas storage side bidirectional flow meter 302 are ultrasonic bidirectional flow meters. The equipment-side bidirectional flow meter 301 is installed on the compressed gas pipeline near the compressor 110 and the air turbine 120, while the gas storage side bidirectional flow meter 302 is installed on the compressed gas pipeline near the gas storage tank 200. Both the equipment-side bidirectional flow meter 301 and the gas storage side bidirectional flow meter 302 are connected to the signal input terminals of the flow selection module 305, and the signal output terminals of the flow selection module 305 are electrically connected to the gas injection algorithm unit 410 and the gas sampling algorithm unit 420, respectively. The flow selection module 305 averages the flow values ​​collected by the equipment-side bidirectional flow meter 301 and the gas storage side bidirectional flow meter 302 and then transmits the averaged values ​​to the gas injection algorithm unit 410 and the gas sampling algorithm unit 420, thereby improving detection accuracy.

[0056] The gas production regulating valve group is used to regulate the working fluid flow rate during the gas production process; the gas injection regulating valve group is used to regulate the working fluid flow rate during the gas injection process. The gas production regulating valve group and the gas injection regulating valve group are arranged in parallel in the gas storage pipeline. According to different operating conditions of the gas storage, the corresponding regulating valve group is activated to ensure the safe and stable operation of the wellbore. The operation method of the dispatching and control system for the parallel wellhead of the compressed air energy storage gas storage of this invention is as follows: Gas injection condition: Ensure that the third isolation valve 603, the fourth isolation valve 604, and the gas production regulating valve 620 in the gas production regulating valve group are in the closed state; open the first isolation valve 601 and the second isolation valve 602; gradually open the gas injection regulating valve 610; adjust the opening degree of the gas injection regulating valve 610 through the gas injection control unit 410 to ensure that the working fluid flow rate in the wellbore is within a safe range. Gas production operation: Ensure that the first isolation valve 601, the second isolation valve 602, and the gas injection regulating valve 610 in the gas injection regulating valve group are closed. Open the third isolation valve 603 and the fourth isolation valve 604, and gradually open the gas production regulating valve 620. Adjust the opening degree of the gas production regulating valve 620 through the gas production control unit 420 to ensure that the working fluid flow rate in the wellbore is within a safe range. In addition, for gas storage facilities with multiple wells operating in parallel, the injection and production wells should be put into operation in sequence according to the principle of "nearest first, then farthest" based on their relative distance from the plant area.

[0057] The gas production control module and the gas injection control module include input terminals IN1, IN2, and IN3, an output terminal OUT, setpoint terminals Vm, D, and t, wellbore flow velocity conversion functions F2(x) and F3(x), valve flow characteristic function F1(x), a high-value alarm H1, a low-value alarm L1, a PID control unit, and switching switches T1 and T2. Input terminals IN1, IN2, and IN3 represent the gas storage side pressure, gas storage side temperature, and pipeline flow rate, respectively. The output terminal OUT of the gas injection algorithm unit 410 is connected to the gas injection regulating valve 610, and the output terminal OUT of the gas production algorithm unit 420 is connected to the gas production regulating valve 620. Both the high-value alarm H1 and the low-value alarm L1 are electrically connected to the pressure measuring sensor 303. The high-value alarm H1 is set with an upper pressure alarm value. When the pressure data detected by the pressure measuring sensor 303 exceeds the upper pressure alarm value, an alarm is issued to protect the salt cavern chamber and prevent overpressure within the chamber. The low-value alarm L1 is set with a lower pressure alarm value. When the pressure data detected by the pressure measuring sensor 303 is lower than the lower pressure alarm value, an alarm is issued to protect the salt cavern chamber and prevent pressure loss and collapse within the chamber. The valve flow characteristic function F1(x) is used to map the output signal of the PID controller into the valve degree signal of the flow valve. This is existing technology. The wellbore flow velocity conversion function F2(x) is a density conversion function used to execute formula (1) in the embodiment. The wellbore flow velocity conversion function F3(x) is a flow velocity conversion function used to execute formula (2) in the embodiment. The PID control unit executes formula (3) in the embodiment. Switches T1 and T2 are used to transmit a zero valve opening signal to the gas injection regulating valve 610 and the gas sampling regulating valve 620 when the pressure exceeds the set value, thereby closing the entire compressed gas pipeline.

[0058] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A scheduling and control method for parallel wellheads of compressed air energy storage gas storage facilities, characterized in that: Includes the following steps: Obtain the pressure, temperature, and pipeline flow rate of the gas storage facility; The real-time flow velocity in the pipeline is calculated based on the pressure and temperature of the gas storage side and the pipeline flow rate. The real-time flow velocity in the pipeline is compared with the preset target flow velocity, and a PID control signal is generated with the real-time flow velocity in the pipeline reaching the target flow velocity as the objective. The opening degree of the regulating valve in the compressed gas pipeline is controlled by the PID control signal to regulate the pipeline flow rate.

2. The scheduling and control method for parallel wellheads of compressed air energy storage gas storage tanks according to claim 1, characterized in that: The real-time flow velocity in the pipeline, calculated based on the gas storage side pressure, gas storage side temperature, and pipeline flow rate, includes: First, calculate the density of the compressed gas in the pipeline. The specific calculation formula is as follows: （1）； in, This indicates the density of the compressed gas. Indicates the pressure on the gas storage side. Represents the specific gas constant. This indicates the temperature on the gas storage side; Next, calculate the real-time flow velocity in the pipe. The specific calculation formula is as follows: （2）； in, This indicates the real-time flow rate in the pipeline. Indicates pipeline flow rate, Indicates the outer diameter of the injection / production pipe. This indicates the wall thickness of the injection / production tube.

3. The scheduling and control method for parallel wellheads of compressed air energy storage gas storage tanks according to claim 1, characterized in that: The formula for generating the PID control signal is: （3）； in, For PID control signals, For proportional gain, This represents the deviation signal, specifically the difference between the target flow velocity and the real-time flow velocity in the pipeline. For integral gain, Historical traffic error For differential gain, Indicates the current moment.

4. The scheduling and control method for parallel wellheads of compressed air energy storage gas storage tanks according to claim 1, characterized in that: If the pressure on the gas storage side is greater than the upper pressure alarm value or less than the lower pressure alarm value, the opening of the regulating valve in the control pipeline will be zero.

5. A scheduling and control system for parallel wellheads of compressed air energy storage gas storage facilities, characterized in that: include: The system includes a compressor (110), an air turbine (120), and a gas storage tank (200). The compressor (110) and air turbine (120) are connected to the gas storage tank (200) via compressed gas pipelines. An injection pipeline and a gas sampling pipeline are connected in parallel along the middle of the compressed gas pipelines. Injection regulating valve groups and gas sampling regulating valve groups are respectively installed on the injection pipeline and the gas sampling pipeline. A pressure measuring sensor (303) and a temperature measuring sensor (304) are installed on the compressed gas pipeline near the gas storage tank (200). A flow meter is provided. The pressure measuring sensor (303), temperature measuring sensor (304) and flow meter are all electrically connected to the signal input terminals of the gas injection algorithm unit (410) and the gas extraction algorithm unit (420). The signal output terminals of the gas injection algorithm unit (410) and the gas extraction algorithm unit (420) are electrically connected to the gas injection regulating valve group and the gas extraction regulating valve group, respectively. The gas injection algorithm unit (410) and the gas extraction algorithm unit (420) are configured to execute the scheduling and control method of the parallel wellhead of the compressed air energy storage gas storage tank according to any one of claims 1 to 4.

6. The scheduling and control system for parallel wellheads of compressed air energy storage gas storage tanks according to claim 5, characterized in that: The flow meter includes a device-side bidirectional flow meter (301) and a gas storage-side bidirectional flow meter (302). The device-side bidirectional flow meter (301) is located on the compressed gas pipeline near the compressor (110) and air turbine (120). The gas storage-side bidirectional flow meter (302) is located on the compressed gas pipeline near the gas storage (200). The device-side bidirectional flow meter (301) and the gas storage-side bidirectional flow meter (302) are respectively connected to the signal input terminal of the flow selection module (305). The signal output terminal of the flow selection module (305) is respectively electrically connected to the gas injection algorithm unit (410) and the gas sampling algorithm unit (420).

7. The scheduling and control system for parallel wellheads of compressed air energy storage gas storage tanks according to claim 5, characterized in that: The gas injection regulating valve group includes a first isolation valve (601), a second isolation valve (602) and a gas injection regulating valve (610). The first isolation valve (601) and the second isolation valve (602) are located on both sides of the gas injection regulating valve (610). The gas injection regulating valve (610) is electrically connected to the gas injection algorithm unit (410).

8. The scheduling and control system for parallel wellheads of compressed air energy storage gas storage tanks according to claim 5, characterized in that: The gas extraction regulating valve group includes a third isolation valve (603), a fourth isolation valve (604), and a gas extraction regulating valve (620). The third isolation valve (603) and the fourth isolation valve (604) are located on both sides of the gas extraction regulating valve (620), and the gas extraction regulating valve (620) is electrically connected to the gas extraction algorithm unit (420).

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