A method and system for controlling the output flow of a fracturing pump

Abstract

The present invention provides a method and system for controlling the output flow rate of a fracturing pump. The method includes: obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump; determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value; in the case where the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, so as to control the flow rate output by the fracturing pump. The method for controlling the output flow rate of the fracturing pump provided by the present invention can timely correct the output flow rate deviation of the fracturing pump, effectively reduce the fluctuation amount, and thus improve the flow rate stability and working quality of the fracturing pump.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent control, and relates to a method and system for controlling the output flow rate of a fracturing pump. In addition, it also relates to an electronic device and a processor-readable storage medium. Background Art

[0002] A fracturing pump is a petroleum machine used for pumping sand-mixed fluid and fracturing in the process of increasing oil production in oil fields. For a fracturing pump driven by a hydraulic cylinder, its transmission system uses a hydraulic cylinder to drive a fracturing piston, and through the coordinated action of multiple hydraulic cylinders, the stable output of the output flow rate of the fracturing pump is achieved. In the prior art, usually, the stroke of the hydraulic cylinder is collected by a hydraulic cylinder stroke sensor, and the controller performs timing control and connection control on the stroke of the hydraulic cylinder to achieve closed-loop control of the strokes of multiple hydraulic cylinders. However, the function of the hydraulic cylinder is to drive the fracturing piston to output flow rate, and the output flow rate of the fracturing piston and its stability are the ultimate working quality of the fracturing pump. Only the closed-loop control of the hydraulic cylinder stroke is performed, while the output flow rate of the fracturing piston is still open-loop controlled, and the flow rate deviation caused by interference factors such as leakage and air suction cannot be corrected. In the actual working process of the fracturing piston system, the leakage conditions of each piston are different and changing, the frictional resistance of the piston is different and changing, and the fracturing piston may also be air suctioned. These interference factors cause the output flow rate of the fracturing piston to be unstable, thereby affecting the working quality of the fracturing pump.

[0003] Therefore, there is currently a lack of a practical technical solution to effectively control the flow rate stability of multiple fracturing pistons, resulting in low flow rate stability and working quality of the fracturing pump. How to design a more effective fracturing pump output flow rate control scheme to improve control stability has become an urgent technical problem to be solved. Summary of the Invention

[0004] For this reason, the present invention provides a method and system for controlling the output flow rate of a fracturing pump to solve the problem that the control accuracy of the fracturing pump output flow rate control scheme in the prior art is low, resulting in poor operation stability and working quality.

[0005] The present invention provides a method for controlling the output flow rate of a fracturing pump, including:

[0006] Obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump;

[0007] Based on the actual flow rate data, determining the flow rate fluctuation amount of the fracturing pump, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value;

[0008] When the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, the control current of the hydraulic valve of the fracturing pump is adjusted based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump.

[0009] Further, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump includes:

[0010] Based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, and a preset current adjustment amount estimation model, determine the corresponding current adjustment amount; wherein, the current adjustment amount estimation model is a PID control model obtained by adjusting parameters based on historical data and using an online learning method;

[0011] Based on the current adjustment amount, increase or decrease the current of the first hydraulic valve controlling the movement of the first hydraulic cylinder to control the magnitude of the flow rate output by the fracturing pump; and / or, based on the current adjustment amount, increase or decrease the current of the second hydraulic valve controlling the movement of the second hydraulic cylinder to control the magnitude of the flow rate output by the fracturing pump;

[0012] Wherein, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0013] Further, after adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes:

[0014] Adjust the start time of the hydraulic valve that controls the fracturing pump to start commutation;

[0015] The adjustment of the start time of the hydraulic valve that controls the fracturing pump to start commutation specifically includes: adjusting the start time of the first hydraulic valve that controls the first hydraulic cylinder to start commutation; and / or, adjusting the start time of the second hydraulic valve that controls the second hydraulic cylinder to start commutation; the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0016] Further, the first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; if the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

[0017] Further, before adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes:

[0018] Compare the difference with a preset threshold value to determine whether the difference is less than or greater than the preset threshold value. If so, determine whether the current fracturing pump is in a commutation state.

[0019] Further, the determination of whether the current fracturing pump is in a commutation state specifically includes: obtaining the start time of the first hydraulic valve when the first hydraulic cylinder starts to commutate and / or the start time of the second hydraulic valve when the second hydraulic cylinder starts to commutate, and determining whether the fracturing pump is in a commutation state based on the sequence relationship between the current time and the start time; or,

[0020] Obtain the running speed change information of the first hydraulic cylinder and / or the running speed change information of the second hydraulic cylinder, and determine whether the fracturing pump is in a commutation state based on the running speed change information; or,

[0021] Obtain the distance information of the first hydraulic cylinder to the stroke end point and / or the distance information of the second hydraulic cylinder to the stroke end point, and determine whether the fracturing pump is in a commutation state based on the distance information.

[0022] Further, determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data specifically includes: obtaining two flow rate data within a preset time interval from the actual flow rate data; and determining the flow rate fluctuation amount of the fracturing pump based on the difference between the two flow rate data.

[0023] The present invention also provides a fracturing pump output flow control system, including:

[0024] A flow rate detection module for obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump;

[0025] A fluctuation amount analysis module for determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data and determining the difference between the flow rate fluctuation amount and the preset fluctuation amount value;

[0026] A first flow rate control module for adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value when the difference is greater than or less than the preset threshold value and the current fracturing pump is in a commutation state, so as to control the flow rate output by the fracturing pump.

[0027] Further, the first flow rate control module is specifically used for:

[0028] Determine a corresponding current adjustment amount based on the difference between the flow rate fluctuation amount and a preset fluctuation amount value, and a preset current adjustment amount estimation model; wherein, the current adjustment amount estimation model is a PID control model obtained by adjusting parameters based on historical data and using an online learning method;

[0029] Increase or decrease the current of the first hydraulic valve that controls the movement of the first hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump; and / or, increase or decrease the current of the second hydraulic valve that controls the movement of the second hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump;

[0030] Wherein, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0031] Further, the flow rate output control system of the fracturing pump further includes: a second flow rate control module; the second flow rate control module is used for: when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjust the starting time of the hydraulic valve that controls the fracturing pump to start commutation;

[0032] The adjustment of the starting time of the hydraulic valve that controls the fracturing pump to start commutation specifically includes: adjusting the starting time of the first hydraulic valve that controls the first hydraulic cylinder to start commutation; and / or, adjusting the starting time of the second hydraulic valve that controls the second hydraulic cylinder to start commutation; the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0033] Further, the first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; if the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

[0034] Further, before adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes:

[0035] A judgment module, used to compare the difference with a preset threshold, judge whether the difference is less than or greater than the preset threshold, and if so, judge whether the current fracturing pump is in a commutation state.

[0036] Further, the determination module is specifically configured to: obtain the start time of the first hydraulic valve when the first hydraulic cylinder starts to reverse and / or the start time of the second hydraulic valve when the second hydraulic cylinder starts to reverse, and determine whether the fracturing pump is in a reversing state based on the sequence relationship between the current time and the start time; or,

[0037] obtain the operating speed change information of the first hydraulic cylinder and / or the operating speed change information of the second hydraulic cylinder, and determine whether the fracturing pump is in a reversing state based on the operating speed change information; or,

[0038] obtain the distance information of the first hydraulic cylinder to the stroke end point and / or the distance information of the second hydraulic cylinder to the stroke end point, and determine whether the fracturing pump is in a reversing state based on the distance information.

[0039] Further, the fluctuation amount analysis module is specifically configured to: obtain two flow rate data within a preset time interval from the actual flow rate data; and determine the flow rate fluctuation amount of the fracturing pump based on the difference between the two flow rate data.

[0040] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the fracturing pump output flow rate control method as described in any one of the above are implemented.

[0041] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the fracturing pump output flow rate control method as described in any one of the above are implemented.

[0042] The fracturing pump output flow rate control method provided by the present invention determines the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data output by the fracturing pump, and determines the difference between the flow rate fluctuation amount and a preset fluctuation amount value. When the difference is greater than or less than a preset threshold and the current fracturing pump is in a reversing state, the control current of the hydraulic valve of the fracturing pump is adjusted based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump. It can timely correct the output flow rate deviation of the fracturing pump, effectively reduce the fluctuation amount, and thus improve the flow rate stability and working quality of the fracturing pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 is one of the schematic flowcharts of the output flow control method of the fracturing pump provided by the present invention;

[0045] Figure 2 is the second of the schematic flowcharts of the output flow control method of the fracturing pump provided by the present invention;

[0046] Figure 3 is the third of the schematic flowcharts of the output flow control method of the fracturing pump provided by the present invention;

[0047] Figure 4 is the schematic structural diagram of the output flow control system of the fracturing pump provided by the present invention;

[0048] Figure 5 is the schematic structural diagram of the electronic device provided by the present invention. Detailed Embodiments

[0049] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0050] The following is a detailed description of the embodiments based on the output flow control method of the fracturing pump described in the present invention. As Figure 1 shown, it is the schematic flowchart of the output flow control method of the fracturing pump provided by the embodiments of the present invention, and the specific implementation process includes the following steps:

[0051] Step 101: Obtain the actual flow rate data output by the fracturing pump.

[0052] As Figure 2 shown, the fracturing pump may also be a piston pump composed of piston cylinders driven by multiple hydraulic cylinders. The actual flow rate data includes the output flow rate data of all pistons (such as 3 pistons) included in the fracturing pump or piston pump. In the specific implementation process, the output pressure data of the piston pump composed of piston cylinders driven by multiple hydraulic cylinders may also be collected, so as to adjust the control current or switching time of the two hydraulic cylinders participating in the stroke connection and switching in the subsequent steps, so as to reduce the fluctuation amount of the output flow rate or output pressure of the piston pump and improve the smoothness.

[0053] In addition, it should be noted that during the detection process, in addition to collecting the actual flow rate data Q output by the fracturing pump, it is also necessary to pre-collect the control current IA of the hydraulic valve A (i.e., the first hydraulic valve), the start time TA of the hydraulic valve A, the control current IB of the hydraulic valve B (i.e., the second hydraulic valve), and the start time TB of the hydraulic valve B. Among them, the hydraulic valve A refers to the control hydraulic valve of a hydraulic cylinder A of the plunger pump, and the hydraulic cylinder A is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulically connected cylinders. The hydraulic valve A refers to the control hydraulic valve of a hydraulic cylinder A of the plunger pump, and the hydraulic cylinder A is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulically connected cylinders; the start time TA refers to the start time when the control current of the hydraulic valve A changes from near the maximum value to near the zero value. The hydraulic valve B refers to the control hydraulic valve of a hydraulic cylinder B of the plunger pump, and the hydraulic cylinder B is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulically connected cylinders. The hydraulic valve B refers to the control hydraulic valve of a hydraulic cylinder B of the plunger pump, and the hydraulic cylinder B is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulically connected cylinders; the start time TB refers to the start time when the control current of the hydraulic valve B changes from near the maximum value to near the zero value.

[0054] Step 102: Determine the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, and determine the difference between the flow rate fluctuation amount and the preset fluctuation amount value.

[0055] During the implementation of this step, two flow rate data at a preset time interval can be obtained from the actual flow rate data; based on the difference between the two flow rate data, the flow rate fluctuation amount of the fracturing pump is determined. Specifically, Figure 3As shown, calculate the flow rate fluctuation δQ of the piston pump. The calculation method is: the difference between two sampled values of the piston pump flow rate; compare the flow rate fluctuation δQ with a preset fluctuation value δQ1 to determine whether δQ is greater than δQ1. Here, δQ1 is a constant greater than zero. In S32, compare the flow rate fluctuation δQ with a preset fluctuation value δQ2 to determine whether δQ is less than δQ2. Here, δQ2 is a constant less than zero. Further, determine whether the current piston pump is in a commutation state. The determination method is: after the hydraulic valve A (the first hydraulic valve) or the hydraulic valve B (the second hydraulic valve) is in its commutation time, the piston pump is in the commutation process. The first hydraulic valve and the second hydraulic valve are two hydraulic cylinders with connected strokes. When δQ is greater than δQ1 and the piston pump is in the commutation state, take at least one of the following measures: reduce the current of the hydraulic valve A or the hydraulic valve B; and / or, change the start time of the hydraulic valve A or the hydraulic valve B. Here, the specific method of changing the start time of the hydraulic valve A or the hydraulic valve B is: advance the start time of the hydraulic valve A, or delay the start time of the hydraulic valve B. When δQ is less than δQ2 and the piston pump is in the commutation state, take at least one of the following measures: increase the current of the hydraulic valve A or the hydraulic valve B; change the start time of the hydraulic valve A or the hydraulic valve B. The specific method is: delay the start time of the hydraulic valve A, or advance the start time of the hydraulic valve B.

[0056] Step 103: When the difference is greater than or less than a preset threshold and the current fracturing pump is in the commutation state, adjust the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation and the preset flow rate fluctuation value to control the flow rate output by the fracturing pump.

[0057] During the implementation of this step, it is necessary to compare the difference with the preset threshold in advance to determine whether the difference is less than or greater than the preset threshold. If so, determine whether the current fracturing pump is in the commutation state. Here, the specific implementation process of determining whether the current fracturing pump is in the commutation state includes: obtaining the start time of the first hydraulic valve when the first hydraulic cylinder starts to commutate and / or the start time of the second hydraulic valve when the second hydraulic cylinder starts to commutate, and determining whether the fracturing pump is in the commutation state based on the sequence relationship between the current time and the start time. For example, the current time exceeds the start time; or, obtaining the running speed change information of the first hydraulic cylinder and / or the running speed change information of the second hydraulic cylinder, and determining whether the fracturing pump is in the commutation state based on the running speed change information. For example, the running speed is in a dynamic change process of decreasing or increasing; or, obtaining the distance information of the first hydraulic cylinder to the stroke end point and / or the distance information of the second hydraulic cylinder to the stroke end point, and determining whether the fracturing pump is in the commutation state based on the distance information. For example, the distance information is less than a preset distance threshold.

[0058] When the difference is greater than or less than a preset threshold and the current fracturing pump is in the commutation state, based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, and a preset current adjustment amount estimation model, determine the corresponding current adjustment amount. Among them, the current adjustment amount estimation model is a PID control model (i.e., Proportional Integral Derivative, proportional, integral, and differential control system) obtained by adjusting parameters based on historical data and using an online learning method. Then, based on the current adjustment amount, increase or decrease the current of the first hydraulic valve that controls the movement of the first hydraulic cylinder to control the size of the flow rate output by the fracturing pump; and / or, based on the current adjustment amount, increase or decrease the current of the second hydraulic valve that controls the movement of the second hydraulic cylinder to control the size of the flow rate output by the fracturing pump. Among them, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder. The first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; if the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

[0059] In addition, when the difference is greater than or less than a preset threshold and the current fracturing pump is in the commutation state, the start time of the hydraulic valve (such as hydraulic valve A or hydraulic valve B) that controls the start of commutation of the fracturing pump can also be adjusted. Specifically, the adjustment of the start time of the hydraulic valve that controls the start of commutation of the fracturing pump corresponds to the following implementation process: adjust the start time of the first hydraulic valve that controls the start of commutation of the first hydraulic cylinder; and / or, adjust the start time of the second hydraulic valve that controls the start of commutation of the second hydraulic cylinder. The fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder. The first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes. If the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

[0060] In an embodiment of the present invention, when the difference ΔQ is greater than a preset threshold value ΔQ1 and the piston pump is in a commutation state, at least one of the following measures is taken: reducing the current of hydraulic valve A or hydraulic valve B or changing the start time of hydraulic valve A or hydraulic valve B.

[0061] Specifically, when the difference ΔQ is greater than the preset threshold value ΔQ1 and the piston pump is in a commutation state, it indicates that there is a stroke overlap during the commutation of hydraulic cylinder A and hydraulic cylinder B. The method for reducing and eliminating the stroke overlap is to reduce the speed of hydraulic cylinder A or reduce the speed of hydraulic cylinder B and delay its commutation time. Therefore, the speed of hydraulic cylinder A can be controlled to decrease by reducing the current of hydraulic valve A, thereby controlling the flow rate of hydraulic valve A to decrease; of course, the speed of hydraulic cylinder B can also be decreased by reducing the current of hydraulic valve B, thereby reducing the flow rate of hydraulic valve B. Further, the method for reducing the current of hydraulic valve A or hydraulic valve B is: performing PID control on ΔQ, that is, the current adjustment amount estimation model corresponding to the adjustment current of the hydraulic valve is: ΔI = P×ΔQ + I×∑ΔQ + D×dΔQ / dt; where P, I, and D are preset coefficients; furthermore, the values of P, I, and D can be adjusted in real time based on historical data and using an online learning method.

[0062] During the control process, the coefficients such as P, I, and D are fine-tuned one by one to see if ΔQ decreases. If ΔQ decreases, the coefficients are updated until ΔQ reaches the minimum.

[0063] Changing the start time of hydraulic valve A (i.e., the first hydraulic valve) or hydraulic valve B (i.e., the second hydraulic valve), the specific method is: advancing the start time of hydraulic valve A or delaying the start time of hydraulic valve B. When the difference ΔQ is greater than the preset threshold value ΔQ1 and the piston pump is in a commutation state, it indicates that there is a stroke overlap during the commutation of hydraulic cylinder A and hydraulic cylinder B. The method for reducing and eliminating the stroke overlap is: pausing the movement of hydraulic cylinder A or B for a short period of time. The specific method is: the meaning of advancing the start time of hydraulic valve A is that as long as hydraulic cylinder B has commuted, regardless of whether hydraulic cylinder A has reached the end point of the maximum stroke (i.e., reached the end), immediately control hydraulic valve A to make hydraulic cylinder A commute; the meaning of delaying the start time of hydraulic valve B is: although hydraulic cylinder B has reached the end and can commute, because hydraulic cylinder A has not reached the end, hydraulic cylinder B stops at the end and waits for hydraulic cylinder A to reach the end before commuting simultaneously.

[0064] When the difference ΔQ is less than the preset threshold value ΔQ2 and the piston pump is in a commutation state, at least one of the following measures is taken: increasing the current of hydraulic valve A or hydraulic valve B or changing the start time of hydraulic valve A or hydraulic valve B.

[0065] Specifically, when the difference ΔQ is greater than a preset threshold ΔQ1 and the piston pump is in the commutation state, it indicates that there is a stroke overlap during the commutation of hydraulic cylinder A and hydraulic cylinder B. The methods for increasing and eliminating the stroke overlap are to increase the speed of hydraulic cylinder A or increase the speed of hydraulic cylinder B to delay its commutation time. Therefore, the current of hydraulic valve A can be increased to control the increase in the flow rate of hydraulic valve A, thereby increasing the speed of hydraulic cylinder A; of course, the current of hydraulic valve B can also be increased to control the increase in the flow rate of hydraulic valve B, thereby increasing the speed of hydraulic cylinder B. Further, the method for increasing the current of hydraulic valve A or hydraulic valve B is: perform PID control on ΔQ, that is, the adjustment current ΔI of the hydraulic valve = P×ΔQ + I×∑ΔQ + D×dΔQ / dt; where P, I, and D are preset coefficients; furthermore, the values of P, I, and D can be adjusted in real time through online learning. For example: during the control process, fine-tune the coefficients such as P, I, and D one by one to see if ΔQ increases. If ΔQ increases, update the coefficients until ΔQ reaches the minimum.

[0066] Change the start time of hydraulic valve A or hydraulic valve B. The specific method is: delay the start time of hydraulic valve A or advance the start time of hydraulic valve B. When the difference ΔQ is greater than a preset threshold ΔQ1 and the piston pump is in the commutation state, it indicates that there is a stroke overlap during the commutation of hydraulic cylinder A and hydraulic cylinder B. The methods for reducing and eliminating the stroke overlap are: pause the movement of hydraulic cylinder A or B for a short period of time. The specific method is: the meaning of delaying the start time of hydraulic valve A is that as long as hydraulic cylinder B has commuted, regardless of whether hydraulic cylinder A has reached the end point of the maximum stroke (i.e., reached the end), immediately control hydraulic valve A to make hydraulic cylinder A commute; the meaning of advancing the start time of hydraulic valve B is: although hydraulic cylinder B has reached the end point and can commute, because hydraulic cylinder A has not reached the end point yet, hydraulic cylinder B stops at the end point and waits for hydraulic cylinder A to reach the end point before commuting simultaneously. In the actual implementation process, the stroke signal of the hydraulic cylinder can be collected to determine whether the end point of the maximum stroke is reached. For example: the distance from the initial point to the end point of the maximum stroke is 100 cm. At this time, hydraulic cylinder A is the hydraulic cylinder that pushes forward, and its stroke reaches the end point of the maximum forward stroke, that is, 100 cm; at this time, hydraulic cylinder B is the hydraulic cylinder that pulls backward, and its stroke has not reached the end point of the maximum backward stroke, such as 90 cm; correspondingly, the short period of time can be the time required for hydraulic cylinder B to continue moving from the 90 cm position to 100 cm, so that when hydraulic cylinder A that pushes forward reaches the end point of the maximum stroke, the hydraulic cylinder B that pulls backward reaches the end point of the maximum backward stroke, thereby maintaining the stability of the output flow rate.

[0067] The method for controlling the output flow rate of a fracturing pump according to the embodiments of the present invention determines the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data output by the fracturing pump, and determines the difference between the flow rate fluctuation amount and a preset fluctuation amount value. When the difference is greater than or less than a preset threshold and the fracturing pump is currently in a commutation state, the control current of the hydraulic valve of the fracturing pump is adjusted based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump. It can timely correct the output flow rate deviation of the fracturing pump, effectively reduce the fluctuation amount, and thus improve the flow rate stability and working quality of the fracturing pump.

[0068] Corresponding to the above-provided method for controlling the output flow rate of a fracturing pump, the present invention also provides a system for controlling the output flow rate of a fracturing pump. Since the embodiments of this system are similar to the above method embodiments, the description is relatively simple. For related parts, please refer to the description in the above method embodiment section. The following description of the embodiments of the system for controlling the output flow rate of a fracturing pump is only illustrative. Please refer to Figure 4 As shown, it is a schematic structural diagram of a system for controlling the output flow rate of a fracturing pump provided by an embodiment of the present invention.

[0069] The system for controlling the output flow rate of a fracturing pump according to the present invention specifically includes:

[0070] A flow rate detection module 401 for obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all pistons included in the fracturing pump;

[0071] A fluctuation amount analysis module 402 for determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value;

[0072] A first flow rate control module 403 for adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value when the difference is greater than or less than a preset threshold and the fracturing pump is currently in a commutation state to control the flow rate output by the fracturing pump.

[0073] Further, the first flow rate control module is specifically used for:

[0074] Determining a corresponding current adjustment amount based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value and a preset current adjustment amount estimation model; wherein, the current adjustment amount estimation model is a PID control model obtained by adjusting parameters based on historical data and using an online learning method.

[0075] Based on the current adjustment amount, increase or decrease the current of the first hydraulic valve that controls the movement of the first hydraulic cylinder, so as to control the output flow rate of the fracturing pump; and / or, based on the current adjustment amount, increase or decrease the current of the second hydraulic valve that controls the movement of the second hydraulic cylinder, so as to control the output flow rate of the fracturing pump;

[0076] Wherein, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0077] Further, the output flow rate control system of the fracturing pump further includes: a second flow control module; the second flow control module is used for: when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjust the start time of the hydraulic valve that controls the start of commutation of the fracturing pump;

[0078] The adjustment of the start time of the hydraulic valve that controls the start of commutation of the fracturing pump specifically includes: adjusting the start time of the first hydraulic valve that controls the start of commutation of the first hydraulic cylinder; and / or, adjusting the start time of the second hydraulic valve that controls the start of commutation of the second hydraulic cylinder; the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder.

[0079] Further, the first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; if the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

[0080] Further, before adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes:

[0081] A judgment module, which is used to compare the difference with a preset threshold, judge whether the difference is less than or greater than the preset threshold, and if so, judge whether the current fracturing pump is in a commutation state.

[0082] Further, the judgment module is specifically used for: obtaining the start time of the first hydraulic valve for the first hydraulic cylinder to start commutation and / or the start time of the second hydraulic valve for the second hydraulic cylinder to start commutation, and judging whether the fracturing pump is in a commutation state based on the sequence relationship between the current time and the start time; or,

[0083] Obtain the operating speed change information of the first hydraulic cylinder and / or the operating speed change information of the second hydraulic cylinder, and determine whether the fracturing pump is in a commutation state based on the operating speed change information; or,

[0084] Obtain the distance information of the first hydraulic cylinder to the stroke end point and / or the distance information of the second hydraulic cylinder to the stroke end point, and determine whether the fracturing pump is in a commutation state based on the distance information.

[0085] Further, the fluctuation amount analysis module is specifically configured to: obtain two flow rate data within a preset time interval from the actual flow rate data; and determine the flow rate fluctuation amount of the fracturing pump based on the difference between the two flow rate data.

[0086] In the fracturing pump output flow rate control system according to the embodiment of the present invention, by determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data output by the fracturing pump, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value, when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, the control current of the hydraulic valve of the fracturing pump is adjusted based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump. It can timely correct the output flow rate deviation of the fracturing pump, effectively reduce the fluctuation amount, and thus improve the flow rate stability and working quality of the fracturing pump.

[0087] Corresponding to the above-provided fracturing pump output flow rate control method, the present invention also provides an electronic device. Since the embodiment of this electronic device is similar to the above method embodiment, the description is relatively simple. For related parts, please refer to the description in the above method embodiment part. The following-described electronic device is only illustrative. As Figure 5 shown, it is a schematic diagram of the physical structure of an electronic device disclosed in an embodiment of the present invention. The electronic device may include: a processor 501, a memory 502, and a communication bus 503. Among them, the processor 501 and the memory 502 communicate with each other through the communication bus 503 and communicate with the outside through a communication interface 504. The processor 501 can call the logical instructions in the memory 502 to execute the fracturing pump output flow rate control method, and the method includes: obtaining the actual flow rate data output by the fracturing pump; where the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump; determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value; when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump.

[0088] In addition, when the logical instructions in the above-mentioned memory 502 can be implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0089] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the fracturing pump output flow control method provided by the above-mentioned various methods. The method includes: obtaining the actual flow data output by the fracturing pump; the actual flow data includes the output flow data of all the plungers included in the fracturing pump; determining the flow fluctuation amount of the fracturing pump based on the actual flow data, and determining the difference between the flow fluctuation amount and a preset fluctuation amount value; when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow fluctuation amount and the preset fluctuation amount value to control the flow output by the fracturing pump.

[0090] On another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is configured to execute the fracturing pump output flow control method provided by the above-mentioned various methods. The method includes: obtaining the actual flow data output by the fracturing pump; wherein, the actual flow data includes the output flow data of all the plungers included in the fracturing pump; determining the flow fluctuation amount of the fracturing pump based on the actual flow data, and determining the difference between the flow fluctuation amount and a preset fluctuation amount value; when the difference is greater than or less than a preset threshold and the current fracturing pump is in a commutation state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow fluctuation amount and the preset fluctuation amount value to control the flow output by the fracturing pump.

[0091] The system embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative work.

[0092] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the output flow rate of a fracturing pump, characterized in that, Including: Obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump; Determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value; When the difference is greater than or less than a preset threshold and the fracturing pump is currently in a commutation state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump, including: Determining a corresponding current adjustment amount based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, and a preset current adjustment amount estimation model; wherein, the current adjustment amount estimation model is a PID control model obtained by adjusting parameters based on historical data and using an online learning method; Increasing or decreasing the current of the first hydraulic valve controlling the movement of the first hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump; and / or, increasing or decreasing the current of the second hydraulic valve controlling the movement of the second hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump; Wherein, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder; the hydraulic valves of the fracturing pump include the first hydraulic valve and the second hydraulic valve; After adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes: Adjusting the start time of the hydraulic valve that controls the fracturing pump to start commutation, specifically including: adjusting the start time of the first hydraulic valve that controls the first hydraulic cylinder to start commutation; and / or, adjusting the start time of the second hydraulic valve that controls the second hydraulic cylinder to start commutation; The first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; If the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a moving speed increasing from the minimum value among the two hydraulic cylinders with connected strokes; if the second hydraulic cylinder is the hydraulic cylinder with a stroke close to the maximum value and a moving speed reduced to the minimum value among the two hydraulic cylinders with connected strokes, then the first hydraulic cylinder is the hydraulic cylinder with a stroke close to the minimum value and a speed gradually increasing from the minimum value among the two hydraulic cylinders with connected strokes.

2. The method for controlling the output flow rate of a fracturing pump according to claim 1, wherein, Before adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, it further includes: Comparing the difference with a preset threshold to determine whether the difference is less than or greater than the preset threshold, and if so, determining whether the fracturing pump is currently in a commutation state.

3. The output flow control method of the fracturing pump according to claim 2, characterized in that, The determination of whether the fracturing pump is currently in a commutation state specifically includes: Obtain the starting time of the first hydraulic valve when the first hydraulic cylinder starts to reverse and / or the starting time of the second hydraulic valve when the second hydraulic cylinder starts to reverse, and determine whether the fracturing pump is in a reversing state based on the sequence relationship between the current time and the starting time; or, Obtain the operating speed change information of the first hydraulic cylinder and / or the operating speed change information of the second hydraulic cylinder, and determine whether the fracturing pump is in a reversing state based on the operating speed change information; or, Obtain the distance information of the first hydraulic cylinder to the stroke end point and / or the distance information of the second hydraulic cylinder to the stroke end point, and determine whether the fracturing pump is in a reversing state based on the distance information.

4. The method for controlling the output flow rate of a fracturing pump according to claim 1, characterized in that, Determine the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, specifically including: Obtain two flow rate data within a preset time interval from the actual flow rate data; determine the flow rate fluctuation amount of the fracturing pump based on the difference between the two flow rate data.

5. A flow control system for the output of a fracturing pump, characterized in that, Include: A flow rate detection module for obtaining the actual flow rate data output by the fracturing pump; wherein, the actual flow rate data includes the output flow rate data of all the plungers included in the fracturing pump; A fluctuation amount analysis module for determining the flow rate fluctuation amount of the fracturing pump based on the actual flow rate data, and determining the difference between the flow rate fluctuation amount and a preset fluctuation amount value; A first flow rate control module for, when the difference is greater than or less than a preset threshold and the current fracturing pump is in a reversing state, adjusting the control current of the hydraulic valve of the fracturing pump based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value to control the flow rate output by the fracturing pump, specifically for: Determine the corresponding current adjustment amount based on the difference between the flow rate fluctuation amount and the preset fluctuation amount value, and a preset current adjustment amount estimation model; wherein, the current adjustment amount estimation model is a PID control model obtained by adjusting parameters based on historical data and using an online learning method; Increase or decrease the current of the first hydraulic valve controlling the movement of the first hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump; and / or, increase or decrease the current of the second hydraulic valve controlling the movement of the second hydraulic cylinder based on the current adjustment amount to control the magnitude of the flow rate output by the fracturing pump; Wherein, the fracturing pump includes the first hydraulic cylinder and the second hydraulic cylinder; the hydraulic valves of the fracturing pump include the first hydraulic valve and the second hydraulic valve; It further includes a second flow rate control module for, when the difference is greater than or less than a preset threshold and the current fracturing pump is in a reversing state, adjusting the starting time of the hydraulic valve that controls the fracturing pump to start reversing, specifically including: adjusting the starting time of the first hydraulic valve that controls the first hydraulic cylinder to start reversing; and / or, adjusting the starting time of the second hydraulic valve that controls the second hydraulic cylinder to start reversing; The first hydraulic cylinder and the second hydraulic cylinder are two hydraulic cylinders with connected strokes; If the first hydraulic cylinder is the one with a stroke approaching the maximum value and a moving speed decreasing to the minimum value among the two stroke-connected hydraulic cylinders, then the second hydraulic cylinder is the one with a stroke approaching the minimum value and a moving speed increasing from the minimum value among the two stroke-connected hydraulic cylinders; if the second hydraulic cylinder is the one with a stroke approaching the maximum value and a moving speed decreasing to the minimum value among the two stroke-connected hydraulic cylinders, then the first hydraulic cylinder is the one with a stroke approaching the minimum value and a speed gradually increasing from the minimum value among the two stroke-connected hydraulic cylinders.

6. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the fracturing pump output flow control method according to any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the fracturing pump output flow control method according to any one of claims 1 to 4.

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