A fracturing pump fault detection system and method

Abstract

The application provides a fracturing pump fault detection system and method, relates to the technical field of engineering machinery, and is applied to a fracturing pump. The fracturing pump comprises a cross head, an upper sliding rail and a lower sliding rail, and the cross head is slidingly connected between the upper sliding rail and the lower sliding rail. The fracturing pump fault detection system comprises a controller and a sensor assembly. The upper calibration position of the upper sliding rail and the lower calibration position of the lower sliding rail are respectively provided with the sensor assembly. The sensor assembly comprises at least one of a strain sensor, a linear velocity sensor and a temperature sensor, and the sensor assembly is electrically connected to the controller. By arranging the sensor assembly on the upper sliding rail and the lower sliding rail, the corresponding parameters can be detected by the sensor assembly. The controller can compare the detected actual parameter value with a judgment threshold value, and then judge whether the suction valve sealing element or / and the discharge valve sealing element is damaged or not.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, in particular to a fracturing pump fault detection system and method. BACKGROUND

[0002] Fracturing operation is an important measure to improve oil and gas production and recoverable reserves. Fracturing pump is the main executive mechanism of fracturing operation. According to the working condition of fracturing construction, the fracturing pump is required to have high pressure, large displacement, corrosion resistance and strong wear resistance, etc. This makes the liquid end seal of the fracturing pump easy to wear, especially the upper discharge valve seal and the lower suction valve seal need to be replaced frequently. The existing fracturing pump is usually a 5-cylinder pump or more, and each cylinder has 2 sets of valve body seals that need to be maintained, which is a large amount of maintenance work. Usually, the fracturing pump equipment uses a regular maintenance mode, but this regular maintenance mode may cause over-maintenance and maintenance not in time. Over-maintenance will cause waste of wear parts and increase unnecessary work, and maintenance not in time will cause faults during operation and cause the equipment to be out of service, affecting the entire fracturing construction process. SUMMARY

[0003] The present application aims to solve the problem that the existing fracturing pump cannot accurately and timely know whether the liquid end seal is damaged.

[0004] To solve the above problems, the present application provides a fracturing pump fault detection system applied to a fracturing pump, the fracturing pump comprising a crosshead, an upper slide rail and a lower slide rail, and the crosshead being slidably connected between the upper slide rail and the lower slide rail, the fracturing pump fault detection system comprising a controller and a sensor assembly, the upper calibration position of the upper slide rail and the lower calibration position of the lower slide rail being respectively provided with the sensor assembly, the sensor assembly comprising at least one of a strain sensor, a linear velocity sensor and a temperature sensor, and the sensor assembly being electrically connected with the controller.

[0005] The fracturing pump provided by the present application has the following beneficial effects compared with the prior art, but is not limited to the following:

[0006] In addition to the upper slide rail, the lower slide rail and the crosshead, the fracturing pump usually comprises a crank, a crank connecting rod, a plunger connecting rod and a plunger, wherein when the crank rotates, the crosshead can be driven to move linearly back and forth between the upper slide rail and the lower slide rail through the crank connecting rod, and in turn the plunger connected with the crosshead through the plunger connecting rod is driven to move linearly back and forth, so as to realize the working of the fluid end of the fracturing pump, that is, when the plunger moves backward, the discharge valve on the upper side of the fluid end is closed, the suction valve on the lower side is opened to suck liquid, and when the plunger moves forward, the suction valve is closed and the liquid is compressed to discharge high-pressure liquid from the discharge valve. If the discharge valve seal or / and the suction valve seal of the fluid end is damaged, some parameters in the fluid end will change under the same working condition, such as the change of internal pressure, the change of internal temperature and the change of plunger moving speed, and the change of these parameters will also cause some parameters in the power end of the fracturing pump to change, such as the actual force of the upper slide rail, the actual force of the lower slide rail, the actual temperature of the upper slide rail, the actual temperature of the lower slide rail, the moving speed of the crosshead, etc. Therefore, the present application sets sensor assemblies at the upper calibration position of the upper slide rail and the lower calibration position of the lower slide rail, so as to detect the corresponding parameters through the sensor assemblies, and the controller automatically compares the actual parameter values detected with the preset judgment threshold, so as to judge whether the suction valve seal or / and the discharge valve seal is damaged, and since the sensor assemblies are arranged on the upper slide rail and the lower slide rail in the power end, even if the seal of the fluid end needs to be replaced, the sensor assemblies will not be damaged due to the replacement of the seal, and in addition, since the lower slide rail and the upper slide rail are fixed components, the sensor assemblies are also fixed after being arranged on the fixed components, so that the signal detection of the related parameters is more accurate and the signal transmission is more stable.

[0007] Further, the strain sensors in the two sensor assemblies are arranged at the first upper calibration position of the upper slide rail and the first lower calibration position of the lower slide rail respectively, the first upper calibration position of the upper slide rail is the middle part of the upper slide rail, and the first lower calibration position of the lower slide rail is the middle part of the lower slide rail.

[0008] The present application also provides a fracturing pump fault detection method based on the fracturing pump fault detection system as described above, which comprises the following steps:

[0009] The sensor assemblies arranged at the upper slide rail and the sensor assemblies arranged at the lower slide rail acquire the corresponding parameter values respectively;

[0010] According to the parameter values and the preset judgment threshold, it is determined whether the suction valve seal or / and the discharge valve seal of the fracturing pump is damaged.

[0011] The application can detect corresponding parameters through the sensor assemblies, and the controller compares the detected actual parameter values with preset judgment thresholds, and then judges whether the suction valve seal or / and the discharge valve seal is damaged or not.

[0012] Further, the corresponding parameter values obtained by the sensor assembly arranged at the upper slide rail and the sensor assembly arranged at the lower slide rail respectively include:

[0013] The first actual force value of the upper slide rail under the calibration condition is detected by the first upper strain sensor arranged at the first upper calibration position of the upper slide rail, and the second actual force value of the lower slide rail under the calibration condition is detected by the first lower strain sensor arranged at the first lower calibration position of the lower slide rail.

[0014] The preset judgment threshold includes an upper slide rail force threshold and a lower slide rail force threshold under the calibration condition.

[0015] The determination of whether the suction valve seal or / and the discharge valve seal of the fracturing pump is damaged or not according to the parameter values and the preset judgment threshold includes:

[0016] When the first actual force value is greater than the upper slide rail force threshold, the discharge valve seal of the corresponding liquid cylinder is damaged; or / and, when the second actual force value is less than the lower slide rail force threshold, the suction valve seal of the corresponding liquid cylinder is damaged.

[0017] Further, the corresponding parameter values obtained by the sensor assembly arranged at the upper slide rail and the sensor assembly arranged at the lower slide rail respectively include:

[0018] When the crosshead retreats, the first actual temperature of the upper slide rail under the calibration condition is detected by the second upper temperature sensor arranged at the second upper calibration position of the upper slide rail, and when the crosshead advances to work, the second actual temperature of the lower slide rail under the calibration condition is detected by the second lower temperature sensor arranged at the second lower calibration position of the lower slide rail.

[0019] The preset judgment threshold includes an upper slide rail temperature threshold and a lower slide rail temperature threshold under the calibration condition.

[0020] The determination of whether the suction valve seal or / and the discharge valve seal of the fracturing pump is damaged or not according to the parameter values and the preset judgment threshold includes:

[0021] when the first actual temperature is higher than the upper slide rail temperature threshold, the exhaust valve seal of the corresponding cylinder is failed; or / and, when the second actual temperature is lower than the lower slide rail temperature threshold, the suction valve seal of the corresponding cylinder is failed.

[0022] Further, the parameters values obtained by the sensor assembly arranged at the upper slide rail and the sensor assembly arranged at the lower slide rail respectively include:

[0023] a third upper linear velocity sensor arranged at a third upper calibration position of the upper slide rail and / or a third lower linear velocity sensor arranged at a third lower calibration position of the lower slide rail are arranged to detect actual forward speed and actual backward speed of the cross head;

[0024] the preset judgment threshold includes forward speed threshold and backward speed threshold under the calibration working condition;

[0025] the determination of whether the suction valve seal and / or the exhaust valve seal of the fracturing pump is failed according to the parameter values and the preset judgment threshold includes:

[0026] when the actual forward speed is greater than the forward speed threshold, the suction valve seal of the corresponding cylinder is failed; or / and, when the actual backward speed is less than the backward speed threshold, the exhaust valve seal of the corresponding cylinder is failed.

[0027] Further, the fracturing pump fault detection method further includes:

[0028] the obtaining of the preset judgment threshold includes:

[0029] establishing a threshold judgment data table based on the working condition when the suction valve seal and the exhaust valve seal are good, wherein the threshold judgment data table includes force values of the upper slide rail and the lower slide rail under different set working conditions;

[0030] when the calibration working condition during construction matches one of the set working conditions in the threshold judgment data table, the force value of the upper slide rail under the set working condition is taken as the upper slide rail force threshold, and the force value of the lower slide rail under the set working condition is taken as the lower slide rail force threshold.

[0031] Further, the fracturing pump fault detection method further includes:

[0032] the obtaining of the preset judgment threshold includes:

[0033] the lower slide rail force threshold is determined according to a first formula;

[0034] the first formula is:

[0035] determining the upper slide rail stress threshold according to a second formula;

[0036] The second formula is:

[0037] Wherein, a is a crosshead force coefficient, b1 is a lower slide rail stress coefficient, b2 is an upper slide rail stress coefficient, c1 is a correction value of the lower slide rail affected by other forces, c2 is a correction value of the upper slide rail affected by other forces, P1 is a discharge pressure, P2 is a suction pressure, d is a diameter of the plunger, and m is a weight of the crosshead.

[0038] Further, the fracturing pump fault detection method further comprises:

[0039] Obtaining the preset judgment threshold comprises:

[0040] According to the sum of the actual stresses of the lower slide rails in all hydraulic cylinders under the calibration condition, the average stress of the lower slide rails under the calibration condition is obtained, and the average stress of the lower slide rails under the calibration condition is taken as the lower slide rail stress threshold.

[0041] According to the sum of the actual stresses of the upper slide rails in all hydraulic cylinders under the calibration condition, the average stress of the upper slide rails under the calibration condition is obtained, and the average stress of the upper slide rails under the calibration condition is taken as the upper slide rail stress threshold.

[0042] Further, the fracturing pump fault detection method further comprises:

[0043] Obtaining the preset judgment threshold comprises:

[0044] A digital twin model is established, and simulation analysis is performed through the digital twin model to obtain the preset judgment threshold under the calibration condition. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a structure schematic diagram of the hydraulic end of the fracturing pump of the embodiment of the present application;

[0046] Figure 2 It is a structure schematic diagram of the power end of the fracturing pump of the embodiment of the present application;

[0047] Figure 3 It is a flowchart of the embodiment of the present application Figure 1 ;

[0048] Figure 4 It is a flowchart of the embodiment of the present application Figure 2 ;

[0049] Figure 5 It is a flowchart of the embodiment of the present application Figure 3 ;

[0050] Figure 6 Flowchart of the embodiment of the present application Figure 4 .

[0051] Reference signs:

[0052] 1, crank; 2, crank connecting rod; 3, upper slide rail; 4, lower slide rail; 5, crosshead; 6, plunger connecting rod; 7, sensor assembly; 8, suction valve; 9, discharge valve; 10, plunger. DETAILED DESCRIPTION

[0053] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings.

[0054] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the present application.

[0055] Moreover, in the drawings, the Z-axis represents the vertical direction, that is, the up-down position, and the positive direction of the Z-axis, that is, the direction in which the arrow of the Z-axis points, represents the up direction, and the negative direction of the Z-axis, that is, the direction opposite to the positive direction of the Z-axis, represents the down direction; in the drawings, the X-axis represents the longitudinal direction, that is, the front-rear position, and the positive direction of the X-axis, that is, the direction in which the arrow of the X-axis points, represents the front direction, and the negative direction of the X-axis, that is, the direction opposite to the positive direction of the X-axis, represents the rear direction.

[0056] It should be noted that the above-mentioned meanings of the Z-axis and the X-axis are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the present application.

[0057] Referring to Figure 1 and Figure 2 , the fracturing pump fault detection system of the embodiment is applied to a fracturing pump, the fracturing pump comprises a crosshead 5, an upper slide rail 3 and a lower slide rail 4, the crosshead 5 is slidingly connected between the upper slide rail 3 and the lower slide rail 4, the fracturing pump fault detection system comprises a controller and a sensor assembly 7, the upper calibration position of the upper slide rail 3 and the lower calibration position of the lower slide rail 4 are respectively provided with the sensor assembly 7, the sensor assembly 7 comprises at least one of a strain sensor, a linear velocity sensor and a temperature sensor, and the sensor assembly 7 is electrically connected with the controller.

[0058] In this embodiment, in addition to the cross head 5, the upper slide rail 3 and the lower slide rail 4, the pressure pump usually further comprises a crank 1, a crank connecting rod 2, a plunger connecting rod 6 and a plunger 10, the crank 1, the crank connecting rod 2, the cross head 5, the plunger connecting rod 6 and the plunger 10 are sequentially connected, when the crank 1 rotates, the cross head 5 can be driven to reciprocate linearly between the upper slide rail 3 and the lower slide rail 4 through the crank connecting rod 2, and in turn drive the plunger 10 connected with the cross head 5 through the plunger connecting rod 6 to reciprocate linearly, finally realize the working of the fluid end of the fracturing pump, that is, when the plunger 10 moves backward, the discharge valve 9 on the upper side of the fluid end is closed, the suction valve 8 on the lower side is opened and liquid is sucked in, when the plunger 10 moves forward, the suction valve 8 is closed and the liquid is compressed, so that the high-pressure liquid is discharged from the discharge valve 9. Among them, if the discharge valve seal or / and the suction valve seal of the fluid end is damaged and fails, some parameters in the fluid end under the same working condition will change, such as the change of internal pressure, the change of internal temperature, the change of the moving speed of the plunger 10, and the change of some parameters in the power end of the fracturing pump caused by the change of these parameters, such as the actual stress of the upper slide rail 3, the actual stress of the lower slide rail 4, the actual temperature of the upper slide rail 3, the actual temperature of the lower slide rail 4, the moving speed of the cross head 5, etc. Therefore, in this embodiment, the sensor assembly 7 is arranged at the upper calibration position of the upper slide rail 3 and the lower calibration position of the lower slide rail 4, respectively, so that the corresponding parameters can be detected by the sensor assembly 7, and the actual parameter values detected by the controller are compared with the preset judgment threshold value, so as to judge whether the suction valve seal or / and the discharge valve seal is damaged and fails. Moreover, since the sensor assembly 7 is arranged on the upper slide rail 3 and the lower slide rail 4 in the power end, even if the seal of the fluid end needs to be replaced, the sensor assembly 7 will not be damaged due to the replacement of the seal. In addition, since the lower slide rail 4 and the upper slide rail 3 are fixed components, the sensor assembly 7 is fixed after being arranged on the fixed components, the signal detection of the related parameters is more accurate and the signal transmission is more stable. Moreover, since the sensor assembly 7 is fixed, power supply and signal transmission can be realized by wired mode, which can further improve the detection accuracy of the corresponding signal of the related parameters and the stability of the signal transmission, and the cable will not move, avoiding the winding or interference with other components.

[0059] Referring to Figure 3 , another embodiment of the present application also provides a fracturing pump fault detection method based on the fracturing pump fault diagnosis system described above, the fracturing pump fault detection method comprises:

[0060] S1: acquiring the corresponding parameter values by the sensor assembly 7 arranged at the upper slide rail 3 and the sensor assembly 7 arranged at the lower slide rail 4, respectively;

[0061] S2: determining whether the suction valve seal or / and the discharge valve seal of the fracturing pump is invalid according to the parameter value and a preset judgment threshold.

[0062] In the embodiment, the sensor assembly 7 is arranged at the upper calibration position of the upper slide rail 3 and the lower calibration position of the lower slide rail 4, so that the corresponding parameters can be detected by the sensor assembly 7, and the controller compares the detected actual parameter value with the preset judgment threshold, and then determines whether the suction valve seal or / and the discharge valve seal is damaged or invalid.

[0063] Referring to Figure 4 , the corresponding parameter values obtained by the sensor assembly 7 arranged at the upper slide rail 3 and the sensor assembly 7 arranged at the lower slide rail 4 include:

[0064] S11: detecting a first actual force value of the upper slide rail 3 under the calibration condition by a first upper strain sensor arranged at a first upper calibration position of the upper slide rail 3, and detecting a second actual force value of the lower slide rail 4 under the calibration condition by a first lower strain sensor arranged at a first lower calibration position of the lower slide rail 4;

[0065] The preset judgment threshold includes an upper slide rail force threshold and a lower slide rail force threshold under the calibration condition;

[0066] The determining whether the suction valve seal or / and the discharge valve seal of the fracturing pump is invalid according to the parameter value and a preset judgment threshold includes:

[0067] S21: when the first actual force value is greater than the upper slide rail force threshold, the discharge valve seal of the corresponding hydraulic cylinder is invalid; or / and, when the second actual force value is less than the lower slide rail force threshold, the suction valve seal of the corresponding hydraulic cylinder is invalid.

[0068] In the embodiment, in combination with Figure 2, the crank 1 is only in the initial position of the rear side (when the crank 1 rotates 0°) and rotates to the most front side position (when the crank 1 rotates 180°), the crank connecting rod 2 is in a horizontal state, when the crank 1 rotates to other positions, the crank connecting rod 2 is inclined, and the force given by the inclined crank connecting rod 2 to the cross head 5 will have a vertical component acting on the upper slide rail 3 or the lower slide rail 4. Specifically, when the crank connecting rod 2 drives the cross head 5 to advance, it gives the lower slide rail 4 a downward component force, and when the crank connecting rod 2 drives the cross head 5 to retreat, it gives the upper slide rail 3 an upward component force. In this embodiment, the first lower strain sensor at the first lower calibration position of the lower slide rail 4 detects the second actual force value of the lower slide rail 4 under the calibration working condition, and if the second actual force value of the lower slide rail 4 under the calibration working condition is less than the lower slide rail force threshold value under the calibration working condition, it indicates that the internal pressure of the cross head 5 increases when the cross head 5 advances, that is, the high-pressure liquid in the exhaust pipe manifold connected to the exhaust valve 9 flows into the cylinder cavity from the damaged exhaust valve seal, at this time the controller can control the alarm device or the display device to output the prompt of the exhaust valve seal failure of the corresponding cylinder (here the corresponding cylinder refers to the cylinder where the exhaust valve seal is damaged).

[0069] In addition, in this embodiment, the first upper strain sensor and the first lower strain sensor are arranged at the first upper calibration position of the upper slide rail 3 and the first lower calibration position of the lower slide rail 4 respectively, so that even if the seal of the hydraulic end needs to be replaced, the sensor assembly 7 will not be damaged due to the replacement of the seal. In addition, since the lower slide rail 4 and the upper slide rail 3 are fixed components, the first upper strain sensor and the first lower strain sensor are arranged behind the fixed components, and the first upper strain sensor and the first lower strain sensor are also fixed, so that the signal detection of the related parameters is more accurate and the signal transmission is more stable.

[0070] It should be noted that the first upper strain sensor detects the force of the upper slide rail 3 at the first upper calibration position, and the first lower strain sensor detects the force of the lower slide rail 4 at the first lower calibration position.

[0071] Optionally, the strain sensors in the two sensor assemblies 7 are arranged at a first upper calibration position of the upper slide rail 3 and a first lower calibration position of the lower slide rail 4 respectively, the first upper calibration position of the upper slide rail 3 is a middle part of the upper slide rail 3, and the first lower calibration position of the lower slide rail 4 is a middle part of the lower slide rail 4.

[0072] In the embodiment, referring to Figure 2 , the first upper strain sensor is arranged at the middle part of the upper slide rail 3, and the first lower strain sensor is arranged at the middle part of the lower slide rail 4. In this way, when the crank 1 rotates to the uppermost 90° position, the inclination angle of the crank connecting rod 2 reaches the maximum, and the downward component force of the lower slide rail 4 is the largest. By arranging the first lower strain sensor at the middle part of the lower slide rail 4, the first lower strain sensor is most easily subjected to force detection at this position. Similarly, when the crank 1 rotates to the lowermost 270° position, the inclination angle of the crank connecting rod 2 also reaches the maximum, and the upward component force of the upper slide rail 3 is the largest. By arranging the first upper strain sensor at the middle part of the upper slide rail 3, the first upper strain sensor is most easily subjected to force detection at this position.

[0073] Referring to Figure 5 , optionally, the respective parameter values obtained by the sensor assembly 7 arranged at the upper slide rail 3 and the sensor assembly 7 arranged at the lower slide rail 4 include:

[0074] S12: When the crosshead 5 retreats, the first actual temperature of the upper slide rail 3 under the calibration working condition is detected by the second upper temperature sensor arranged at the second upper calibration position of the upper slide rail 3; when the crosshead 5 advances to work, the second actual temperature of the lower slide rail 4 under the calibration working condition is detected by the second lower temperature sensor arranged at the second lower calibration position of the lower slide rail 4.

[0075] The preset judgment threshold value includes an upper slide rail temperature threshold value and a lower slide rail temperature threshold value under the calibration working condition;

[0076] The determination of whether the suction valve seal or / and the discharge valve seal of the fracturing pump is invalid according to the parameter values and the preset judgment threshold value includes:

[0077] S22: When the first actual temperature is higher than the upper slide rail temperature threshold value, the discharge valve seal of the corresponding hydraulic cylinder is invalid; or / and, when the second actual temperature is lower than the lower slide rail temperature threshold value, the suction valve seal of the corresponding hydraulic cylinder is invalid.

[0078] In the embodiment, when the crosshead 5 is advancing, the suction valve 8 is closed and the discharge valve 9 is opened. If the second actual temperature of the lower slide 4 at the second lower calibration position is lower than the lower slide temperature threshold value under the calibration working condition, it is very likely that the internal liquid temperature is exchanged with the low-temperature liquid in the external suction manifold due to the failure of the suction valve seal. At this time, the controller can control the display device or the alarm device to output a prompt of the failure of the suction valve seal of the corresponding cylinder. When the crosshead 5 is retreating, the suction valve 8 is opened and the discharge valve 9 is closed. If the first actual temperature of the upper slide 3 at the first upper calibration position is higher than the upper slide temperature threshold value under the calibration working condition, it is very likely that the high-temperature liquid in the discharge manifold enters the cylinder chamber due to the failure of the discharge valve seal. At this time, the controller can control the display device or the alarm device to output a prompt of the failure of the discharge valve seal of the corresponding cylinder.

[0079] Referring to Figure 6 Optionally, the respective parameter values are obtained by the sensor assembly 7 arranged at the upper slide 3 and the sensor assembly 7 arranged at the lower slide 4, respectively, and the respective parameter values include:

[0080] S13: detecting the actual advancing speed and the actual retreating speed of the crosshead 5 by a third upper linear speed sensor arranged at a third upper calibration position of the upper slide 3 and / or a third lower linear speed sensor arranged at a third lower calibration position of the lower slide 4.

[0081] The preset judgment threshold values include an advancing speed threshold value and a retreating speed threshold value under the calibration working condition.

[0082] The determination of whether the suction valve seal or / and the discharge valve seal of the fracturing pump is failed according to the parameter values and the preset judgment threshold values includes:

[0083] S23: when the actual advancing speed is greater than the advancing speed threshold value, the suction valve seal of the corresponding cylinder is failed; or / and when the actual retreating speed is less than the retreating speed threshold value, the discharge valve seal of the corresponding cylinder is failed.

[0084] In this embodiment, when the crosshead 5 advances, the suction valve 8 is closed and the exhaust valve 9 is opened. If the actual advancing speed of the crosshead 5 passing through the third lower calibration position of the lower slide rail 4 is greater than the advancing speed threshold value in the calibration condition when the crosshead 5 advances, it indicates that the suction valve seal may be damaged and fail, causing the internal pressure of the cylinder cavity to leak. At this time, the controller can control the alarm device or the display device to output a prompt that the suction valve seal of the corresponding hydraulic cylinder has failed. When the crosshead 5 retreats, the suction valve 8 is opened and the exhaust valve 9 is closed. If the actual retreating speed of the crosshead 5 passing through the third upper calibration position of the upper slide rail 3 is greater than the retreating speed threshold value in the calibration condition, it indicates that the exhaust valve seal may be damaged and fail, causing the internal pressure of the cylinder cavity to increase, so that the actual retreating speed of the crosshead 5 passing through the third lower calibration position of the lower slide rail 4 is greater than the retreating speed threshold value in the calibration condition. At this time, the controller can control the alarm device or the display device to output a prompt that the exhaust valve seal of the corresponding hydraulic cylinder has failed.

[0085] Alternatively, whether the suction valve seal is damaged and fails can be determined by a combination of the above-mentioned methods. That is, when the second actual force value of the lower slide rail 4 in the calibration condition is less than the lower slide rail force threshold value in the calibration condition, and when the second actual temperature of the lower slide rail 4 in the calibration condition is lower than the lower slide rail temperature threshold value in the calibration condition, and when the actual advancing speed of the crosshead 5 is greater than the advancing speed threshold value of the crosshead 5 in the calibration condition, it is determined that the suction valve seal has failed. In this way, it can be ensured that there will be no false judgment.

[0086] Similarly, whether the exhaust valve seal is damaged and fails can be determined by a combination of the above-mentioned methods. That is, when the first actual force value of the upper slide rail 3 in the calibration condition is greater than the upper slide rail force threshold value in the calibration condition, and when the first actual temperature of the upper slide rail 3 in the calibration condition is higher than the upper slide rail temperature threshold value in the calibration condition, and when the actual retreating speed of the crosshead 5 is less than the retreating speed threshold value of the crosshead 5 in the calibration condition, it is determined that the exhaust valve seal of the corresponding hydraulic cylinder has failed. In this way, it can be ensured that there will be no false judgment.

[0087] Alternatively, the following conditions should be met before the fracturing pump fault detection method is executed: the pressure fluctuation of the fracturing pump discharge pressure is ≤1 MPa, the suction pressure is >0 MPa, and the input shaft speed is greater than 0. In this way, it is confirmed that the fracturing pump is in a load working state, and false judgments caused by no-load or speed waiting conditions are prevented.

[0088] Alternatively, the fracturing pump fault detection method further comprises:

[0089] The preset judgment threshold is obtained by establishing a threshold judgment data table based on the working conditions when the suction valve seal and the discharge valve seal are in good condition, wherein the threshold judgment data table includes the force values of the upper slide rail 3 and the lower slide rail 4 under different set working conditions.

[0090] When the calibration working condition during construction matches one of the set working conditions in the threshold judgment data table, the force value of the upper slide rail 3 under the set working condition is taken as the upper slide rail force threshold, and the force value of the lower slide rail 4 under the set working condition is taken as the lower slide rail force threshold.

[0091] Table 1 - Threshold judgment data table

[0092]

[0093] In this embodiment, when the suction valve seal and the discharge valve seal are in good condition, or through other same type of fault-free fracturing pumps, a threshold judgment data table is established, as shown in Table 1 above.

[0094] It should be noted that the threshold judgment data table is obtained by fitting various set working conditions, such as different discharge pressure operating parameters, different gear parameters, and corresponding force values of the upper slide rail 3 and the lower slide rail 4, or / and temperature values of the upper slide rail 3 and the lower slide rail 4, or / and moving speed of the crosshead 5 when advancing and moving speed of the crosshead 5 when retreating. Then, when the calibration working condition during actual work of the fracturing pump completely matches one of the set working conditions in the threshold judgment data table, the controller automatically takes the force value of the upper slide rail 3 under the corresponding set working condition in the threshold judgment data table as the upper slide rail force threshold, and takes the force value of the lower slide rail 4 under the corresponding working condition in the threshold judgment data table as the lower slide rail force threshold.

[0095] Of course, the temperature values of the upper slide rail 3 not shown in the last column of Table 1, which are replaced by ellipses “…”, can also be used as the upper slide rail temperature threshold when the crosshead 5 retreats, the temperature values of the lower slide rail 4 not shown in the last column of Table 1, which are replaced by ellipses “…”, can also be used as the lower slide rail temperature threshold when the crosshead 5 advances, the advancing speed values of the crosshead 5 not shown in the last column of Table 1, which are replaced by ellipses “…”, can also be used as the advancing speed threshold, and the retreating speed values of the crosshead 5 not shown in the last column of Table 1, which are replaced by ellipses “…”, can also be used as the retreating speed threshold. The ellipses “…” in the last row of Table 1 represent corresponding parameter values under different discharge pressures under other gear speeds.

[0096] Optionally, the fracturing pump fault detection method further comprises:

[0097] The preset judgment threshold is obtained by establishing a threshold judgment data table based on the working conditions when the suction valve seal and the discharge valve seal are in good condition, wherein the threshold judgment data table includes the force values of the upper slide rail 3 and the lower slide rail 4 under different set working conditions.

[0098] determining the lower slide rail force threshold according to a first formula;

[0099] The first formula is:

[0100] determining the upper slide rail force threshold according to a second formula;

[0101] The second formula is:

[0102] Wherein, a is a crosshead force coefficient, b1 is a lower slide rail force coefficient, b2 is an upper slide rail force coefficient, c1 is a correction value of the lower slide rail affected by other forces, c2 is a correction value of the upper slide rail affected by other forces, P1 is a discharge pressure, P2 is a suction pressure, d is the diameter of the plunger 10, and m is the weight of the crosshead 5.

[0103] In this embodiment, the lower slide rail force threshold can be calculated by the first formula, a is a crosshead force coefficient, after the installation position of the strain sensor on the slide rail is determined, the vertical force of the crosshead 5 to the slide rail is constant when the crosshead 5 moves to this position; b1 is a lower slide rail force coefficient, due to the difference in structure, material and stiffness of the lower slide rail 4, the force transmitted to the strain sensor will be different, after the lower slide rail 4 is selected in this embodiment, the ability of the lower slide rail 4 to transmit force to the strain sensor is also determined, therefore b1 is also a constant value, and b2 is also a constant value, c1 is a correction value of the lower slide rail 4 affected by other forces, such as the inertia force of the crosshead 5 and the connecting rod 2, the friction force between the crosshead 5 and the lower slide rail 4, and c2 is also a constant correction value, such as the inertia force of the crosshead 5 and the connecting rod 2, the friction force between the crosshead 5 and the upper slide rail 3, therefore, when calculating the lower slide rail force threshold, only the variable P1 is needed to obtain the lower slide rail force threshold under the corresponding working condition, and similarly, when calculating the upper slide rail force threshold, only the variable P2 is needed to obtain the upper slide rail force threshold under the corresponding working condition.

[0104] Optionally, the fracturing pump fault detection method further comprises:

[0105] obtaining the preset judgment threshold, comprising:

[0106] establishing a digital twin model, and performing simulation analysis through the digital twin model to obtain the preset judgment threshold under the calibration condition, wherein the preset judgment threshold comprises the lower slide rail force threshold and the upper slide rail force threshold.

[0107] In the embodiment, the preset judgment threshold under the calibration condition can be obtained by establishing a digital twin model and then performing simulation analysis through the digital twin model. For example, the lower rail stress threshold and the lower rail stress threshold under the calibration condition can be obtained, and the upper rail temperature threshold and the lower rail temperature threshold can also be obtained. In addition, the forward speed threshold and the backward speed threshold of the crosshead 5 under the calibration condition can also be obtained. The digital twin model can repeatedly collect required data without incurring high experimental costs.

[0108] Optionally, the fracturing pump fault detection method further comprises:

[0109] The preset judgment threshold is obtained, comprising:

[0110] According to the sum of the actual stresses of the lower rails 4 in all hydraulic cylinders under the calibration condition, the average stress of the lower rails 4 under the calibration condition is obtained, and the average stress of the lower rails 4 under the calibration condition is taken as the lower rail stress threshold.

[0111] According to the sum of the actual stresses of the upper rails 3 in all hydraulic cylinders under the calibration condition, the average stress of the upper rails 3 under the calibration condition is obtained, and the average stress of the upper rails 3 under the calibration condition is taken as the upper rail stress threshold.

[0112] In the embodiment, in the calibration condition of actual construction, the sum of the same type of data collected by the sensor assembly 7 in each hydraulic cylinder can be used to calculate the average value of the data, and the average value is taken as the preset judgment threshold of the data. For example, the second actual stress value collected by the first lower strain sensor in all hydraulic cylinders is summed and the average value is calculated, and the average value is taken as the lower rail stress threshold. For example, the first actual stress value collected by the first upper strain sensor in all hydraulic cylinders is summed and the average value is calculated, and the average value is taken as the upper rail stress threshold. In addition, the upper rail temperature threshold of the upper rail 3 under the calibration condition, the lower rail temperature threshold of the lower rail 4 under the calibration condition, the forward speed threshold of the crosshead 5, and the backward speed threshold of the crosshead 5 can also be calculated in this way.

[0113] The above-mentioned various methods for obtaining the preset judgment threshold can ensure the derivation of the preset judgment threshold and avoid unexpected situations. Among them, the first actual stress value of the upper rail 3 under the calibration condition can be obtained by collecting multiple data through the corresponding sensor, and the average value of the multiple data is taken as the first actual stress value of the upper rail 3. Similarly, the second actual stress value of the lower rail 4, the first actual temperature value of the upper rail 3, the second actual temperature value of the lower rail 4, the actual forward speed of the crosshead 5, and the actual backward speed of the crosshead 5 can also be obtained by collecting multiple data through the corresponding sensor, and the average value of the multiple data is taken as the corresponding actual value, further improving the accuracy of fault determination and preventing individual false signals from interfering with the determination result.

[0114] The terms "first" and "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features.

[0115] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present disclosure.

Claims

1. A fracturing pump fault detection system applied to a fracturing pump, the fracturing pump comprising an upper slide rail (3), a lower slide rail (4) and a crosshead (5), and the crosshead (5) is slidingly connected between the upper slide rail (3) and the lower slide rail (4), characterized in that, The upper slide rail (3) and the lower slide rail (4) are provided with sensor assemblies (7) at the upper calibration position and the lower calibration position respectively, the sensor assemblies (7) comprise at least one of strain sensors, linear velocity sensors and temperature sensors, and the sensor assemblies (7) are electrically connected with a controller; the strain sensors in the two sensor assemblies (7) are arranged at the first upper calibration position of the upper slide rail (3) and the first lower calibration position of the lower slide rail (4) respectively, and the first upper calibration position of the upper slide rail (3) is the middle part of the upper slide rail (3), and the first lower calibration position of the lower slide rail (4) is the middle part of the lower slide rail (4).

2. A method of detecting a failure of a fracturing pump based on the system for detecting a failure of a fracturing pump according to claim 1, characterized by, The method comprises the following steps: Respective parameter values are acquired by the sensor assemblies (7) arranged at the upper slide rail (3) and the sensor assemblies (7) arranged at the lower slide rail (4); Whether the suction valve seal or / and the discharge valve seal of the fracturing pump is invalid is determined according to the parameter values and a preset judgment threshold value.

3. The fracturing pump fault detection method of claim 2, wherein, The method comprises the following steps: The first actual force value of the upper slide rail (3) under a calibration condition is detected by a first upper strain sensor arranged at the first upper calibration position of the upper slide rail (3), and the second actual force value of the lower slide rail (4) under the calibration condition is detected by a first lower strain sensor arranged at the first lower calibration position of the lower slide rail (4); The preset judgment threshold value comprises an upper slide rail force threshold value and a lower slide rail force threshold value under the calibration condition; The method comprises the following steps: When the first actual force value is greater than the upper slide rail force threshold value, the discharge valve seal of the corresponding hydraulic cylinder is invalid; or / and, when the second actual force value is less than the lower slide rail force threshold value, the suction valve seal of the corresponding hydraulic cylinder is invalid.

4. The fracturing pump fault detection method of claim 3, wherein, The method comprises the following steps: When the cross head (5) retreats, the first actual temperature of the upper slide rail (3) under the calibration condition is detected by a second upper temperature sensor arranged at the second upper calibration position of the upper slide rail (3); when the cross head (5) advances to work, the second actual temperature of the lower slide rail (4) under the calibration condition is detected by a second lower temperature sensor arranged at the second lower calibration position of the lower slide rail (4); The preset judgment threshold value comprises an upper slide rail temperature threshold value and a lower slide rail temperature threshold value under the calibration condition; The method comprises the following steps: When the first actual temperature is higher than the upper slide rail temperature threshold, the exhaust valve seal of the corresponding hydraulic cylinder fails; or / and, when the second actual temperature is lower than the lower slide rail temperature threshold, the suction valve seal of the corresponding hydraulic cylinder fails.

5. The method of claim 4, wherein, The corresponding parameter values are respectively obtained by the sensor assembly (7) arranged at the upper slide rail (3) and the sensor assembly (7) arranged at the lower slide rail (4) include: A third upper linear velocity sensor arranged at a third upper calibration position of the upper slide rail (3) and / or a third lower linear velocity sensor arranged at a third lower calibration position of the lower slide rail (4) are used to detect the actual forward speed and the actual reverse speed of the cross head (5); The preset judgment threshold includes a forward speed threshold and a reverse speed threshold under the calibration working condition; The determination of whether the suction valve seal and / or the exhaust valve seal of the fracturing pump fails according to the parameter values and the preset judgment threshold includes: When the actual forward speed is greater than the forward speed threshold, the suction valve seal of the corresponding hydraulic cylinder fails; or / and, when the actual reverse speed is less than the reverse speed threshold, the exhaust valve seal of the corresponding hydraulic cylinder fails.

6. The fracturing pump fault detection method of claim 3, wherein, Further comprising: The preset judgment threshold is obtained by: Based on the working condition when the suction valve seal and the exhaust valve seal are good, a threshold judgment data table is established, wherein the threshold judgment data table includes the stress values of the upper slide rail (3) and the stress values of the lower slide rail (4) under different set working conditions; When the calibration working condition during construction matches one of the set working conditions in the threshold judgment data table, the stress value of the upper slide rail (3) under the set working condition is taken as the upper slide rail stress threshold, and the stress value of the lower slide rail (4) under the set working condition is taken as the lower slide rail stress threshold.

7. The fracturing pump fault detection method of claim 3, wherein, Further comprising: The preset judgment threshold is obtained by: The lower slide rail stress threshold is determined according to the first formula; The first formula is: ; The upper slide rail stress threshold is determined according to the second formula; The second formula is: ; wherein a is a crosshead force coefficient, is a lower slide force coefficient, is an upper slide force coefficient, is a correction value of the lower slide force affected by other forces, is a correction value of the upper slide force affected by other forces, is a discharge pressure, is a suction pressure, d is a diameter of the plunger (10), and m is a weight of the crosshead (5).

8. The fracturing pump fault detection method of claim 3, wherein, Further comprising: The preset judgment threshold is obtained by: According to the sum of the actual stresses of the lower slide rail (4) in all hydraulic cylinders under the calibration working condition, the average stress of the lower slide rail (4) under the calibration working condition is obtained, and the average stress of the lower slide rail (4) under the calibration working condition is taken as the lower slide rail stress threshold; According to the sum of the actual stresses of the upper slide rail (3) in all hydraulic cylinders under the calibration working condition, the average stress of the upper slide rail (3) under the calibration working condition is obtained, and the average stress of the upper slide rail (3) under the calibration working condition is taken as the upper slide rail stress threshold.

9. The fracturing pump fault detection method of claim 2, wherein, Further comprising: The preset judgment threshold is obtained by: A digital twin model is established, and simulation analysis is performed through the digital twin model to obtain the preset judgment threshold under the calibration working condition.

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