Slurry mixing system, control method thereof, storage medium, and controller

Abstract

The application belongs to the field of hydraulic devices, and discloses a mud mixing system, a control method thereof, a storage medium and a controller. The mud mixing system comprises a hydraulic circuit, a throttling flow path and a switching device. A motor and an oil pump are arranged on the hydraulic circuit. The throttling flow path is provided with a throttle valve. The switching device switches the outlet of the motor to be communicated with the throttling flow path or the inlet of the oil pump. After the pressure collision phenomenon occurs, the oil pump is controlled to stop oil supply, the oil liquid driven by the motor is guided to the throttling flow path through the switching device, the damage of the oil pump caused by the oil liquid is avoided, the output of the oil liquid of the motor is gradually adjusted through the throttle valve, the motor is gradually stopped until it is stopped, the damage of the oil pump caused by the sudden closing of the oil pump is avoided, and the excessive output of the mud is avoided to cause the excessive pressure in the mud pipeline and damage the pipeline.

Description

Technical Field

[0001] This invention relates to the field of hydraulic device technology, and in particular to a slurry mixing system and its control method, storage medium, and controller. Background Technology

[0002] Hydraulically driven cementing trucks utilize a closed-loop hydraulic system to power a large pump. The pump's start and stop are controlled by the switching of current through the oil pump. During cementing operations, if a "pressure surge" occurs in the pipeline, the large pump must be manually stopped as soon as possible to prevent damage from excessive pressure. However, manually stopping the pump requires a high level of operator experience, and when the oil pump is stopped abruptly, the mud pump continues to rotate due to inertia, powering the motor and causing a surge in oil pressure flowing from the motor to the oil pump. This results in a significant pressure shock, reducing the lifespan of components and pipelines. Summary of the Invention

[0003] The main objective of this invention is to provide a slurry mixing system and its control method, storage medium, and controller, which aims to solve the problem that excessive impact will occur when the pump stops during a pressure test in the slurry mixing system.

[0004] To achieve the above objectives, the present invention provides a slurry mixing system, comprising:

[0005] A hydraulic circuit, wherein a motor and an oil pump are provided;

[0006] A throttling flow path, wherein a throttling valve is provided on the throttling flow path; and,

[0007] A switching device that switches the outlet of the motor to the throttling flow path or the inlet of the oil pump.

[0008] Optionally, the switching device includes a reversing valve, which includes a first valve port, a second valve port, and a third valve port. The first valve port is connected to the inlet of the oil pump, the second valve port is connected to the outlet of the motor, and the third valve port is connected to the throttling flow path. The second valve port can switch to be connected to either the first valve port or the third valve port.

[0009] Optionally, the mixing system may also include a mud pump connected to the motor drive.

[0010] Optionally, the mixing system further includes an overflow path, an overflow valve is provided on the overflow path, the overflow path is connected to the throttling path, and is connected between the throttling valve and the switching device.

[0011] The present invention also provides a control method for a slurry mixing system, comprising the slurry mixing system according to any one of the above, wherein the control method for the slurry mixing system comprises:

[0012] Determine the maximum operating pressure of the motor, and determine the impact pressure based on the maximum operating pressure;

[0013] After the cementing operation begins, the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor are obtained.

[0014] When the real-time outlet pressure is greater than the impact pressure, the oil pump is controlled to stop supplying oil, and the switching device is controlled to switch the throttling flow path to the outlet of the motor.

[0015] Based on the real-time well casing pressure, reduce the opening of the throttle valve until it is closed.

[0016] Optionally, reducing the opening of the throttle valve until it is closed based on the real-time well casing pressure includes:

[0017] During the process of the real-time well casing pressure rising from the impact pressure to the first preset pressure, the opening of the throttle valve is reduced until it is closed.

[0018] Optionally, after obtaining the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor after the cementing operation begins, the method further includes:

[0019] Determine the adjustment trigger pressure based on the maximum working pressure;

[0020] When the real-time outlet pressure is greater than the adjustment trigger pressure, reduce the power of the oil pump until the real-time outlet pressure is less than or equal to the adjustment trigger pressure.

[0021] Optionally, after obtaining the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor after the cementing operation begins, the method further includes:

[0022] Obtain the preset target flow rate of the mixing system and the cumulative flow rate of the mud pump;

[0023] The adjustment trigger flow is determined based on the preset target flow rate;

[0024] When the cumulative flow rate is greater than the adjustment trigger flow rate, the discharge rate of the mud pump is reduced to less than or equal to the preset discharge rate.

[0025] The present invention also provides a storage medium, characterized in that the storage medium stores a control program for a mixing system, and when the control program for the mixing system is executed by a processor, it implements the control method for the mixing system as described in any of the preceding claims.

[0026] The present invention also provides a controller, characterized in that the controller includes a memory and a processor, and a control program for a mixing system stored in the memory and capable of running on the processor, the control program for the mixing system being configured to implement the steps of the control method for the mixing system as described in any one of the above.

[0027] This invention provides a slurry mixing system in which a motor and an oil pump are hydraulically driven through a hydraulic circuit. The oil pump supplies oil to the motor to drive its rotation. A switching device switches the throttling flow path between the oil pump inlet and the motor outlet. In the event of a collision, the oil pump stops supplying oil. Due to the action of the slurry, the motor continues to rotate. At this time, the oil in the hydraulic circuit continues to flow towards the oil pump. The switching device guides the oil driven by the motor to the throttling flow path, preventing the oil from damaging the pump. Simultaneously, the throttling valve gradually adjusts the oil output of the motor, causing the motor to gradually stop rotating until it stops completely. This avoids damage to the oil pump caused by sudden pump shutdown and allows for gradual motor shutdown, preventing excessive slurry output from causing excessive pressure in the slurry pipeline and damaging the pipeline. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the connection structure of the mixing system provided in the embodiment of the present invention;

[0029] Figure 2 This is a flowchart of the control method for the mixing system provided in the embodiment of the present invention.

[0030] Explanation of icon numbers:

[0031] 100. Mixing system; 11. Motor; 12. Oil pump; 21. Throttle valve; 3. Switching device; 41. Mud pump; 51. Overflow valve.

[0032] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0035] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0036] Please see Figure 1 The present invention provides a mixing system 100, including a hydraulic circuit, a throttling flow path and a switching device 3; the hydraulic circuit is provided with a motor 11 and an oil pump 12; the throttling flow path is provided with a throttling valve 21; the switching device 3 switches the outlet of the motor 11 to the throttling flow path 21 or the inlet of the oil pump 12.

[0037] This invention provides a slurry mixing system 100. The motor 11 and the oil pump 12 are hydraulically driven through a hydraulic circuit. The oil pump 12 supplies oil to the motor 11 to drive the motor 11 to rotate. Through the switching device 3, the throttling flow path is switched to between the inlet of the oil pump 12 and the outlet of the motor 11. After a collision occurs, the oil pump 12 is controlled to stop supplying oil. Due to the action of the slurry, the motor 11 will continue to rotate. At this time, the oil in the hydraulic circuit will continue to flow towards the oil pump 12. The switching device 3 guides the oil driven by the motor 11 to the throttling flow path to avoid the oil pump 12 being damaged due to the oil driving the oil pump. At the same time, the throttling valve 21 gradually adjusts the oil output of the motor 11, so that the motor 11 gradually stops rotating until it stops, avoiding damage to the oil pump caused by sudden shutdown of the oil pump 12. It can also gradually stop the motor 11 to avoid excessive output of slurry causing excessive pressure in the slurry pipeline and damaging the pipeline.

[0038] It should be noted that the switching device 3 can be implemented in various ways, such as a valve group composed of multiple switching valves, which controls the opening and closing of the outlet and inlet of the motor 11 and the oil pump 12, and the passage of the throttling flow path, so as to connect the throttling flow path to the outlet of the motor 11.

[0039] Specifically, in this embodiment, the switching device 3 includes a reversing valve, which includes a first valve port, a second valve port, and a third valve port. The first valve port is connected to the inlet of the oil pump 12, the second valve port is connected to the outlet of the motor 11, and the third valve port is connected to the throttling flow path. The second valve port can switch between the first valve port and the third valve port. In this embodiment, the switching between flow paths is performed using a three-way valve, which is simple to operate and can achieve flow path on / off control while controlling the circuit. The structure is simple and reliable.

[0040] Furthermore, the mixing system 100 also includes a mud pump 41 driven and connected to the motor 11. In this embodiment, the motor 11 drives the mud pump 41 to rotate, so as to transport mud.

[0041] On the other hand, the mixing system 100 also includes an overflow path, on which an overflow valve 51 is provided. The overflow path is connected to the throttling path and also connects to the throttling valve 21 and the switching device 3. In this embodiment, after the throttling valve 21 is connected to the hydraulic circuit, it will gradually close until the throttling path is disconnected. To avoid hydraulic shock caused by the continued operation of the motor 11 at this time, an overflow path is connected between the throttling valve and the switching device 3, and an overflow valve 51 is provided on the overflow path. At the disconnection point of the throttling path, if the motor 11 continues to deliver oil, pressure will accumulate at the throttling valve until a preset pressure value is reached. Then the overflow valve 51 opens to release the oil, avoiding damage to the motor 11 and the throttling valve.

[0042] Based on the above-described mixing system, the present invention also provides a controller for the mixing system. Further, in an embodiment of the present invention, the controller includes a memory, a processor, and a control program for the mixing system stored in the memory. The processor executes the control program for the mixing system to implement the following control method for the mixing system:

[0043] Determine the maximum operating pressure of the motor, and determine the impact pressure based on the maximum operating pressure;

[0044] After the cementing operation begins, the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor are obtained.

[0045] When the real-time outlet pressure is greater than the impact pressure, the oil pump is controlled to stop supplying oil, and the switching device is controlled to switch the throttling flow path to the outlet of the motor.

[0046] Based on the real-time well casing pressure, reduce the opening of the throttle valve until it is closed.

[0047] Optionally, reducing the opening of the throttle valve until it is closed based on the real-time well casing pressure includes:

[0048] During the process of the real-time well casing pressure rising from the impact pressure to the first preset pressure, the opening of the throttle valve is reduced until it is closed.

[0049] Optionally, after obtaining the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor after the cementing operation begins, the method further includes:

[0050] Determine the adjustment trigger pressure based on the maximum working pressure;

[0051] When the real-time outlet pressure is greater than the adjustment trigger pressure, reduce the power of the oil pump until the real-time outlet pressure is less than or equal to the adjustment trigger pressure.

[0052] The present invention also provides a control method for a slurry mixing system, including the above-described slurry mixing system 100, wherein the control method for the slurry mixing system includes:

[0053] S10. Determine the maximum working pressure of the motor, and determine the impact pressure based on the maximum working pressure;

[0054] In this embodiment, the maximum working pressure of the motor 11 is first determined, thereby determining the impact pressure when an impact occurs in the pipeline, which helps to protect the normal operation of the motor 11.

[0055] It should be noted that the step of determining the maximum working pressure of the motor includes determining the maximum working pressure of the motor based on the rated pressure of the well casing in which the mixing system operates, thereby ensuring the safety of the well casing.

[0056] S20. After the cementing operation begins, obtain the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor.

[0057] After the cementing operation begins, the oil pump starts working and delivers oil to the inlet of the motor, driving the motor to start working. At this time, it is necessary to monitor the outlet pressure of the oil pump and the working pressure of the motor in real time in order to determine whether a pressure collision has occurred.

[0058] S30. When the real-time outlet pressure is greater than the impact pressure, control the oil pump to stop supplying oil and control the switching device to switch the throttling flow path to the outlet of the motor.

[0059] If the real-time outlet pressure is greater than the impact pressure, it indicates that the oil pump is causing obstruction when driving the motor, resulting in an increase in the pressure at the oil pump outlet. When the real-time outlet pressure of the oil pump is greater than the impact pressure, it indicates that an impact has occurred.

[0060] The impact pressure is 0.75 times the maximum working pressure.

[0061] S40. Based on the real-time well casing pressure, reduce the opening of the throttle valve until it is closed.

[0062] After the real-time outlet pressure exceeds the impact pressure, although the oil pump is shut down, the motor continues to rotate, causing the oil to flow towards the throttling path. By gradually reducing the opening of the throttling valve until it is closed, the motor gradually reduces its speed and eventually shuts down completely, so that the motor no longer drives the mud flow in the well casing, thus protecting the pressure safety in the well casing.

[0063] Furthermore, step S40 includes:

[0064] S40. During the process of the real-time well casing pressure rising from the impact pressure to the first preset pressure, reduce the opening of the throttle valve until it is closed.

[0065] In this embodiment, when the real-time well casing pressure reaches the impact pressure, the throttle valve begins to close until the real-time well casing pressure reaches the first preset pressure, at which point the throttle valve is closed.

[0066] It should be noted that the first preset pressure is 0.91 times the maximum working pressure.

[0067] On the other hand, step S20 also includes:

[0068] S01. Determine the adjustment trigger pressure based on the maximum working pressure;

[0069] S02. When the real-time outlet pressure is greater than the adjustment trigger pressure, reduce the power of the oil pump until the real-time outlet pressure is less than or equal to the adjustment trigger pressure.

[0070] In this embodiment, after the cementing operation begins, an adjustment trigger pressure is determined. Once the real-time outlet pressure is greater than the adjustment trigger pressure, the power of the oil pump is reduced, the amount of mud delivered in the well casing is reduced, and the risk of pressure impact is reduced.

[0071] On the other hand, after step S20, the following is also included:

[0072] S03. Obtain the preset target flow rate of the mixing system and the cumulative flow rate of the mud pump;

[0073] S04. Determine the adjustment trigger flow rate based on the preset target flow rate;

[0074] S05. When the cumulative flow rate is greater than the adjustment trigger flow rate, reduce the discharge rate of the mud pump to less than or equal to the preset discharge rate.

[0075] When the actual cumulative flow of cement slurry reaches 90% of the theoretical cumulative demand, the control system automatically adjusts the discharge rate of the mud pump to no more than 0.5 cubic meters per minute to avoid large discharge and pressure.

[0076] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A slurry mixing system, characterized in that, include: A hydraulic circuit, wherein a motor and an oil pump are provided; A throttling flow path, wherein a throttling valve is provided on the throttling flow path; as well as, A switching device that switches the outlet of the motor to the throttling flow path or the inlet of the oil pump; The mixing system also includes an overflow path, an overflow valve is provided on the overflow path, the overflow path is connected to the throttling path, and is connected between the throttling valve and the switching device; When a pressure signal indicating a collision during cementing operations is detected, the oil pump is controlled to stop supplying oil, and the switching device is controlled to switch the motor outlet from the inlet connected to the oil pump to the throttling flow path. After the outlet of the motor is connected to the throttling flow path, the opening of the throttling valve is gradually reduced to slow down and stop the motor.

2. The mixing system according to claim 1, characterized in that, The switching device includes a reversing valve, which includes a first valve port, a second valve port, and a third valve port. The first valve port is connected to the inlet of the oil pump, the second valve port is connected to the outlet of the motor, and the third valve port is connected to the throttling flow path. The second valve port can switch to be connected to either the first valve port or the third valve port.

3. The mixing system according to claim 1, characterized in that, The mixing system also includes a mud pump connected to the motor drive.

4. A control method for a slurry mixing system, characterized in that, The mixing system includes any one of claims 1 to 3, and the control method of the mixing system includes: Determine the maximum operating pressure of the motor, and determine the impact pressure based on the maximum operating pressure; After the cementing operation begins, the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor are obtained. When the real-time outlet pressure is greater than the impact pressure, the oil pump is controlled to stop supplying oil, and the switching device is controlled to switch the throttling flow path to the outlet of the motor. Based on the real-time well casing pressure, reduce the opening of the throttle valve until it is closed.

5. The control method for the mixing system according to claim 4, characterized in that, The step of reducing the opening of the throttle valve until it is closed based on the real-time well casing pressure includes: During the process of the real-time well casing pressure rising from the impact pressure to the first preset pressure, the opening of the throttle valve is reduced until it is closed.

6. The control method for the mixing system according to claim 4, characterized in that, After the cementing operation begins, and after obtaining the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor, the process further includes: Determine the adjustment trigger pressure based on the maximum working pressure; When the real-time outlet pressure is greater than the adjustment trigger pressure, reduce the power of the oil pump until the real-time outlet pressure is less than or equal to the adjustment trigger pressure.

7. The control method for the mixing system according to claim 4, characterized in that, After the cementing operation begins, and after obtaining the real-time outlet pressure of the oil pump and the real-time operating pressure of the motor, the process further includes: Obtain the preset target flow rate of the mixing system and the cumulative flow rate of the mud pump; The adjustment trigger flow is determined based on the preset target flow rate; When the cumulative flow rate is greater than the adjustment trigger flow rate, the discharge rate of the mud pump is reduced to less than or equal to the preset discharge rate.

8. A storage medium, characterized in that, The storage medium stores a control program for a mixing system, which, when executed by a processor, implements the control method for the mixing system as described in any one of claims 4 to 7.

9. A controller, characterized in that, The controller includes a memory and a processor, and a control program for the mixing system stored in the memory and capable of running on the processor, the control program for the mixing system being configured to implement the steps of the control method for the mixing system as described in any one of claims 4 to 7.

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