A method for on-site diagnosis of hydraulic control valve performance

Abstract

The present application belongs to the technical field of mechanical equipment maintenance and equipment management, and particularly relates to a hydraulic control valve performance on-site diagnosis method. The method comprises the following steps: step 1, diagnosis of a hydraulic control switch valve; and step 2, diagnosis of a hydraulic control regulating valve. The method has the following advantages: through the diagnosis of the hydraulic control switch valve, the following effects can be achieved: (1) through the measurement of the valve oil pressure and the pull pressure, the effective action area of the hydraulic piston is determined, and accurate results are provided for the subsequent accurate diagnosis of the valve performance; (2) through the measurement of the displacement from opening to closing of the valve, the quick closing time of the valve is determined, and the steam turbine crisis shutdown function of the valve is evaluated. Through the diagnosis of the hydraulic control regulating valve, the following effects can be achieved: (1) through the measurement of the valve oil pressure and the pull pressure, the effective action area of the hydraulic piston is determined, and accurate results are provided for the subsequent accurate diagnosis of the valve performance.

Description

Technical Field

[0001] This invention belongs to the field of mechanical equipment maintenance and equipment management technology, and specifically relates to a method for on-site diagnosis of the performance of hydraulic control valves. Background Technology

[0002] Hydraulic control valves are a common type of equipment in nuclear power plants, especially in emergency shutdown of conventional island turbine generator units, where they play a crucial role. The operating status of the hydraulic system directly affects the safe and stable operation of the nuclear power unit. To ensure the operational status of hydraulic control switches, in addition to comprehensive disassembly and inspection of the hydraulic control valves, the sealing performance, actuation performance, control response performance, and sub-performance of key sub-components of the hydraulic control device can be tested without disassembly. Currently, the traditional method is to remove the hydraulic system from the main equipment and transport it to a specialized manufacturer for offline testing (hydraulic actuators and driven valves are generally large in size and are usually welded to large pipelines on site, making it difficult to conduct overall off-site testing of the valves). This method not only increases the workload on-site but also incurs significant outsourcing costs. In practice, the risks associated with transporting equipment off-site are also relatively high. Furthermore, the drawback of this method is that traditional off-site testing cannot verify the actual performance of the hydraulic actuator valves on-site. Summary of the Invention

[0003] The purpose of this invention is to provide a method for on-site performance diagnosis of hydraulic control valves, which can perform overall performance diagnosis of hydraulic control valves to evaluate whether the functions of hydraulic actuators and valve bodies can meet operational requirements, ensure the reliability of equipment operation in the next cycle, and evaluate whether the status of the hydraulic control module (hydraulic actuator) after maintenance is correct and its impact on the entire hydraulic control system.

[0004] The technical solution of the present invention is as follows: A method for on-site performance diagnosis of a hydraulic control valve, comprising the following steps:

[0005] Step 1: Diagnostic examination of the hydraulic control switching valve;

[0006] Step 2: Diagnose the hydraulic control regulating valve.

[0007] Step 1 includes the following steps:

[0008] Step 11: Measurement of the effective working area of ​​the hydraulic piston;

[0009] Step 12: Valve fast closing time measurement;

[0010] Step 13: Measure valve operating resistance, spring strength, and valve sealing force;

[0011] Step 14: Measurement of internal leakage in the hydraulic device;

[0012] Step 15: Evaluation of the sealing performance of the pressure chamber;

[0013] Step 16: Evaluate the solenoid valve's operating performance.

[0014] Step 11 involves installing tension and compression sensors, ensuring the spring force and cylinder force are perpendicular to the sensor's working surface, and installing a displacement sensor between the cylinder drive rod and the cylinder mounting base. The diagnostic device outputs pressure to slightly increase the pressure in the testing device, causing the tension and compression sensors to change synchronously, while the displacement sensor's displacement remains constant.

[0015] Unit: mm 2

[0016] Step 12 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move in a straight line relative to each other when the valve operates. A safety oil level is established using a diagnostic device. The valve opens, and the diagnostic device simulates a real shut-off function, rapidly releasing the safety oil and quickly closing the valve. After a delay, the diagnostic device establishes the safety oil level again, opens the valve, simulates a real shut-off function, rapidly releasing the safety oil, and quickly closing the valve again. The calculation is then performed.

[0017] Unit: s

[0018] Step 13 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, causing the valve to gradually open until it is fully open. Subsequently, the oil supply port of the diagnostic device slowly and linearly decreases the oil pressure, causing the valve to gradually close until the oil pressure and displacement are zero. The pressure then begins to rise from point 0, gradually increasing to overcome the spring force and operating resistance. At point 1, the valve gradually opens. At point 2, the valve is fully open. The oil pressure continues to rise to point 3, and then begins to decrease. At point 4, the valve begins to close until point 5, when the valve is fully closed. The oil pressure continues to decrease until it reaches zero, returning to point 0.

[0019] The valve's operating resistance is calculated, resulting in a valve operating resistance curve. This curve is then linearly fitted to obtain an average resistance curve with a zero slope. Finally, the spring strength is calculated.

[0020] Unit: N / mm

[0021] Calculate valve sealing force:

[0022] Unit: N.

[0023] Step 14 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure. The valve gradually opens until it is fully open. After reaching point 1, the valve begins to open until it reaches full opening at point 2. The oil pressure then continues to rise until it stops at point 3. During this process, the oil volume of the hydraulic actuator first rises rapidly from point 0 to point 1. Then, as the valve gradually opens, the oil pressure begins to drop until the valve is fully open. At this point, the leakage corresponding to point 2 is the internal leakage of the hydraulic device, i.e., the leakage of the unloading valve and the piston.

[0024] Step 15 involves establishing a safety oil supply for the diagnostic device. The pressure sensor is connected to pressure tap 1. The diagnostic device outputs an oil supply pressure of 1.25 times the operating pressure to P1, maintains the pressure at P1 for 3 minutes, closes the oil supply line and the safety oil line isolation valve, and collects the oil pressure change trend curve. The pressure is maintained for T1, and the pressure chamber leakage rate can be obtained.

[0025] Unit: bar / s

[0026] During the pressure test, leaks can be checked at sealed parts such as external interfaces and modules.

[0027] Step 16 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure relative linear motion between them when the valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device's signal output cable is connected to the test solenoid valve. The diagnostic device establishes safety oil, and its oil supply port slowly outputs a linearly increasing oil pressure, gradually opening the valve until it is fully open. The diagnostic device outputs a energized signal to the test solenoid valve, causing the valve to gradually close to full closure, and the oil pressure drops to zero. The test solenoid valve remains energized. The diagnostic device outputs a de-energized signal to the test solenoid valve, causing the valve to gradually open from closed to fully open, and the oil pressure gradually rises from zero to the working oil pressure. Throughout this process, the displacement-time curve, oil pressure-time curve, and [other parameters] are recorded. Figure 1 If the results are consistent, it indicates that the test solenoid valve is in normal condition. If, through repeated operation, the slope of the upward and downward displacement lines is similar to that of the oil pressure curve, it indicates that the test solenoid valve has not deteriorated significantly.

[0028] Step 2 includes the following:

[0029] Step 21: Measurement of the effective working area of ​​the hydraulic piston;

[0030] Step 22: Measurement of valve operating resistance, spring strength, and valve sealing force;

[0031] Step 23: Measurement of internal leakage of the hydraulic device;

[0032] Step 24: Evaluation of the sealing performance of the pressure chamber;

[0033] Step 25: Servo valve control performance evaluation;

[0034] Step 26: Measure the internal leakage of the servo valve under different valve position states.

[0035] Step 21 involves installing tension / compression sensors, ensuring the spring force and cylinder force are perpendicular to the sensor's working surface, installing a displacement sensor between the cylinder drive rod and the cylinder mounting base, replacing the servo valve with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while the return pipe is blocked, and slightly increasing the pressure output by the diagnostic device to slightly increase the pressure of the testing device. The tension / compression sensors change synchronously, while the displacement sensor's displacement remains constant. Calculations are then performed.

[0036] Unit: mm 2

[0037] Step 22 involves installing a displacement sensor between the moving and fixed parts of the switching valve to ensure that they move linearly relative to each other when the valve operates. A pressure sensor is connected to pressure tap 1. The servo valve is replaced with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while blocking the return pipe. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, gradually opening the valve until it is fully open. Then, the oil supply port of the diagnostic device slowly and linearly decreases the oil pressure, gradually closing the valve until the oil pressure and displacement are zero. The pressure increases from point 0, gradually overcoming the spring force and action resistance. At point 1, the valve gradually opens. At point 2, the valve is fully open. The oil pressure continues to increase to point 3, and then begins to decrease. At point 4, the valve begins to close until point 5, when the valve is fully closed. The oil pressure continues to decrease until it is zero, returning to point 0.

[0038] The valve's actuation resistance is calculated, and the average resistance curve with a zero slope is obtained by linear fitting. The spring strength is then calculated.

[0039] Unit: N / mm

[0040] Calculate valve sealing force:

[0041] Unit: N.

[0042] Step 23 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve operates. A pressure sensor is connected to pressure tap 1. The servo valve is replaced with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while the return pipe is blocked. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure. The valve gradually opens until it is fully open. After reaching point 1, the valve begins to open until it reaches full opening at point 2. The oil pressure then continues to rise until it stops at point 3. During this process, the oil volume of the hydraulic actuator first rises rapidly from point 0 to point 1. Then, as the valve gradually opens, the oil pressure begins to drop until the valve is fully open. At this point, the leakage corresponding to point 2 is the internal leakage of the hydraulic device, i.e., the leakage of the unloading valve and the piston.

[0043] Step 24 involves establishing a safety oil supply for the diagnostic device. The pressure sensor is connected to pressure tap 1. The servo valve is replaced with a dedicated module that allows the oil supply line to communicate with the oil chamber while the return line is blocked. The diagnostic device outputs an oil supply pressure of 1.25 times the operating pressure to P1. The pressure at P1 is maintained for 3 minutes. The isolation valves of the oil supply line and the safety oil line are then closed. The oil pressure change trend curve can be collected. After maintaining the pressure for T1, the leakage rate of the pressure chamber can be obtained.

[0044] Unit: bar / s

[0045] During the pressure test, leaks can be checked at sealed parts such as external interfaces and modules.

[0046] Step 25 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure linear relative movement between them when the valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device's signal output cable is connected to the servo valve. The diagnostic device establishes safety oil and switches its oil supply to a constant operating pressure. The diagnostic device outputs a linearly increasing signal to the servo valve, causing the oil pressure in the oil chamber to rise linearly, while simultaneously opening the valve non-linearly. Subsequently, the diagnostic device outputs a linearly decreasing signal to the servo valve. The diagnostic device also outputs a non-linearly increasing signal to the servo valve, causing it to open linearly. Then, the diagnostic device outputs a non-linearly decreasing signal to the servo valve, causing it to close linearly. Throughout this process, the on-site measured signal-oil pressure curve, oil pressure-displacement curve, and [other parameters] are recorded. Figure 1 If the slopes of the rising and falling displacement lines are similar and the oil pressure curves are similar, it indicates that the servo valve's control performance is not significantly deteriorated.

[0047] Step 26 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device's signal output cable is connected to the servo valve. The diagnostic device establishes safety oil and switches its oil supply to a constant pressure state. The diagnostic device outputs a non-linear rising signal to the servo valve, causing the valve to open linearly and maintain the valve position for 15 seconds. The diagnostic device measures the internal leakage of the servo valve under stable conditions at each valve position and plots the measured internal leakage line segment on each displacement platform.

[0048] The beneficial effects of this invention are as follows: by diagnosing the hydraulic control switching valve, the following effects can be achieved:

[0049] (1) By measuring the valve oil pressure and tension, the effective working area of ​​the hydraulic piston is determined, providing accurate results for subsequent precise diagnosis of valve performance;

[0050] (2) The valve’s rapid closing time is measured by measuring the valve’s displacement from open to closed, and the turbine emergency shutdown function of the valve is evaluated.

[0051] (3) By measuring valve oil pressure and displacement, determine valve action resistance, spring strength, and valve closing force, and evaluate the overall valve action performance, spring performance, and valve sealing function.

[0052] (4) By measuring the leakage of valves, determine the internal leakage of the hydraulic device (the leakage of the unloading valve and piston), evaluate whether the internal leakage of the valve exceeds the standard, and the impact on the entire control oil system;

[0053] (5) Test the pressure chamber of the cylinder, record the rate of oil pressure drop and external leakage, and evaluate the sealing performance of the cylinder pressure chamber;

[0054] (6) Evaluate the performance of the test solenoid valve by testing its on / off operation and valve displacement measurement.

[0055] By diagnosing the hydraulic control regulating valve, the following effects can be achieved:

[0056] (1) By measuring the valve oil pressure and tension, the effective working area of ​​the hydraulic piston is determined, providing accurate results for subsequent precise diagnosis of valve performance;

[0057] (2) By measuring valve oil pressure and displacement, determine valve action resistance, spring strength, and valve closing force, and evaluate the overall valve action performance, spring performance, and valve sealing function.

[0058] (3) By measuring the leakage of valves, determine the internal leakage of hydraulic devices (leakage of unloading valves and pistons), evaluate whether the internal leakage of valves exceeds the standard, and the impact on the entire control oil system;

[0059] (4) Test the pressure chamber of the cylinder, record the rate of oil pressure drop and external leakage, and evaluate the sealing performance of the cylinder pressure chamber;

[0060] (5) Evaluate the control response performance and action performance (whether it jams, etc.) of the servo valve by controlling the servo valve signal and measuring the valve displacement.

[0061] (6) Control the operation of the servo valve with the servo valve signal and measure the internal leakage (mainly the internal leakage of the servo valve) under different valve position states. Evaluate the sealing state and internal wear of the servo valve core by measuring the internal leakage under the servo valve operation state.

[0062] Based on the above parameters, this invention can also comprehensively evaluate whether the hydraulic control module (hydraulic actuator) is in the correct state after maintenance, such as the orifice plate installation status and the correct installation of seals. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the oil circuit of a typical hydraulic control switch valve drive device;

[0064] Figure 2 This is a schematic diagram of the oil circuit of a typical hydraulic control regulating valve drive device;

[0065] Figure 3 For measuring the effective area of ​​the piston;

[0066] Figure 4 For measuring the effective area of ​​the piston;

[0067] Figure 5 For valve fast closing time measurement;

[0068] Figure 6 For measuring valve operating resistance, spring performance, and valve sealing performance;

[0069] Figure 7 The valve's actuation resistance curve;

[0070] Figure 8 For measuring the internal leakage of hydraulic actuators;

[0071] Figure 9 For measuring the internal leakage of hydraulic actuators;

[0072] Figure 10 For the sealing performance of the pressure-bearing boundary of the hydraulic actuator;

[0073] Figure 11 To evaluate the performance of the solenoid valve;

[0074] Figure 12 To evaluate the performance of the solenoid valve;

[0075] Figure 13 For measuring the effective area of ​​the piston;

[0076] Figure 14 For measuring the effective area of ​​the piston;

[0077] Figure 15 For measuring valve operating resistance, spring performance, and valve sealing performance;

[0078] Figure 16 The valve's actuation resistance curve;

[0079] Figure 17 For measuring the internal leakage of hydraulic actuators;

[0080] Figure 18 For measuring the internal leakage of hydraulic actuators;

[0081] Figure 19 For the sealing performance of the pressure-bearing boundary of the hydraulic actuator;

[0082] Figure 20 To supply linear servo valve signals (linear hydraulic pressure);

[0083] Figure 21 Displacement and oil pressure curves under linear servo valve signal;

[0084] Figure 22 The linear displacement curve is given by a nonlinear servo valve signal.

[0085] Figure 23 To control the valve on each linear displacement platform for the servo valve;

[0086] Figure 24 The internal leakage of the servo valve was measured at various displacement platforms. Detailed Implementation

[0087] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0088] A method for on-site performance diagnosis of hydraulic control valves includes diagnosis of hydraulic control switching valves and diagnosis of hydraulic control regulating valves.

[0089] The diagnosis of hydraulic control switching valves includes:

[0090] (1) The effective working area of ​​the hydraulic piston is determined by measuring the valve oil pressure and tension.

[0091] (2) The valve's rapid closing time is determined by measuring the valve's displacement from open to closed;

[0092] (3) Measure the valve's operating resistance, spring strength, and valve closing force by measuring the valve's oil pressure and displacement;

[0093] (4) Measure the internal leakage of the hydraulic device (leakage of the unloading valve and piston) by measuring the leakage of the valve.

[0094] (5) Test the pressure chamber of the oil cylinder and record the rate of oil pressure drop and external leakage.

[0095] (6) Test the on / off operation of the solenoid valve and measure the valve displacement.

[0096] The diagnosis of hydraulic control valves includes:

[0097] The effective working area of ​​the hydraulic piston is determined by measuring the valve oil pressure and tension.

[0098] (2) By measuring valve oil pressure and displacement, the valve action resistance, spring strength, and valve closing force are determined;

[0099] (3) Measure the internal leakage of the hydraulic device (leakage of the unloading valve and piston) by measuring the leakage of the valve.

[0100] (4) Test the pressure chamber of the oil cylinder and record the rate of oil pressure drop and external leakage.

[0101] (5) Servo valve signal control operation and valve displacement measurement;

[0102] (6) Control the operation of the servo valve with the servo valve signal and measure the internal leakage (mainly the internal leakage of the servo valve) under different valve position states.

[0103] like Figure 1-24 As shown, a method for on-site diagnostics of hydraulic control valve performance includes diagnostics of hydraulic control switching valves and diagnostics of hydraulic control regulating valves.

[0104] Step 1: Diagnosis of hydraulic control switching valves

[0105] Step 12: Measurement of the effective working area of ​​the hydraulic piston

[0106] Install tension / compression sensors so that the spring force and cylinder force are perpendicular to the sensor's working surface; install a displacement sensor between the cylinder drive rod and the cylinder mounting base. The diagnostic device outputs pressure to slightly increase the pressure of the testing device (generally less than 0.1 bar), and the tension / compression sensors change synchronously, see... Figure 3 The displacement sensor displacement remains constant (displacement less than 0.1 mm), see attached. Figure 4 It can be calculated:

[0107] Unit: mm 2

[0108] Step 12: Valve quick-closing time measurement

[0109] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move in a linear fashion relative to each other when the valve actuates. A diagnostic device is used to establish a safety oil level (see schematic diagram of a typical hydraulic control valve actuator). When the valve opens, the diagnostic device simulates a real shut-off function, rapidly depleting the safety oil and quickly closing the valve. After a delay, the diagnostic device re-establishes the safety oil level, opens the valve, and again simulates a real shut-off function, rapidly depleting the safety oil and quickly closing the valve. See [link to diagram]. Figure 10 It can be calculated:

[0110] Unit: s

[0111] Step 13: Measurement of valve operating resistance, spring strength, and valve sealing force

[0112] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device establishes safety oil (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device slowly outputs a linearly increasing oil pressure at its supply port, gradually opening the valve until it is fully open. Subsequently, the diagnostic device slowly and linearly decreases the oil pressure at its supply port, gradually closing the valve until the oil pressure and displacement are zero. This process corresponds to the attached diagram. Figure 6 The curve shown illustrates the process. Pressure increases begin at point 0, gradually overcoming spring force and resistance. At point 1, the valve begins to open. At point 2, the valve is fully open, and pressure continues to rise to point 3. Pressure then begins to decrease, starting at point 4 and closing. At point 5, the valve is fully closed, and pressure continues to drop until it reaches zero, returning to point 0.

[0113] Through append Figure 7 The valve's operating resistance can be calculated from the oil pressure values ​​of curves 12 and 45. This is done by multiplying the oil pressure values ​​on the same horizontal axis (for the same valve position) of curves 12 and 45 by the effective operating area A, subtracting the result, and dividing by two. Figure 7 The valve's operating resistance curve is not actually a curve with a zero slope. It is obtained by linear fitting to form an average resistance curve with a zero slope (see appendix). Figure 7 Double-dotted line.

[0114] Through append Figure 6 The spring strength can be calculated from the characteristic points 11, 12, 21, and 22 where vertical lines 1 and 2 intersect the 12-curve and the 45-curve.

[0115] Unit: N / mm

[0116] Through append Figure 7The oil pressure corresponding to feature point 5 at the end of the 45° curve can be used to calculate the valve sealing force.

[0117] Unit: N

[0118] Step 14: Measurement of internal leakage of hydraulic unit (leakage from unloading valve and piston)

[0119] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device establishes safety oil (see schematic diagram of a typical hydraulic control valve actuator), and the diagnostic device slowly outputs a linearly increasing oil pressure from its supply port, gradually opening the valve until it is fully open. (See attached diagram.) Figure 8 , 9 As the oil pressure gradually rises, it primarily overcomes the spring force and friction. After reaching point 1, the valve begins to open, reaching full opening at point 2. The oil pressure then continues to rise, stopping at point 3. During this process, the oil volume in the hydraulic actuator initially increases rapidly from point 0 to point 1. Subsequently, as the valve gradually opens, the oil pressure begins to decrease until the valve is fully open. The leakage at point 2 represents the internal leakage of the hydraulic system, specifically the leakage from the unloading valve and piston. Figure 8 The middle part is Q-leaking.

[0120] Step 15: Evaluation of the sealing performance of the pressure chamber.

[0121] The diagnostic device establishes safety oil (typical hydraulic control switch valve drive device oil circuit diagram); the pressure sensor is connected to pressure tap 1 (typical hydraulic control switch valve drive device oil circuit diagram); the diagnostic device outputs supply oil pressure 1.25 times the operating pressure to P1, maintains the P1 pressure for 3 minutes, closes the supply oil line and safety oil line isolation valve, and can collect data such as... Figure 10 The oil pressure change trend curve shown, with a holding pressure T1, allows us to obtain the pressure chamber leakage rate.

[0122] Unit: bar / s

[0123] During the pressure test, leaks can be checked at sealed parts such as external interfaces and modules.

[0124] Step 16: Evaluation of the solenoid valve's operating performance

[0125] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device's signal output cable is connected to the test solenoid valve. The diagnostic device establishes safety oil (see schematic diagram of a typical hydraulic control valve actuator), and the diagnostic device slowly outputs a linearly increasing oil pressure from its oil supply port, gradually opening the valve until it is fully open. The diagnostic device outputs an energized signal to the test solenoid valve, as shown in the attached diagram. Figure 11 , 12 The valve gradually closes to full closure, and the oil pressure drops to zero (from point 1 to point 2). The test solenoid valve remains energized (points 2 and 3). The diagnostic device outputs a power failure signal to the test solenoid valve, and the valve gradually opens from closed to full closure, causing the oil pressure to gradually rise from zero to the working oil pressure (point 3 to point 4). Throughout the process, the displacement-time curve, oil pressure-time curve, and [other parameters are mentioned]. Figure 1 If the slopes of the upward and downward displacement lines are similar and the oil pressure curves are similar (the Euclidean distance is similar, which will not be elaborated here), it indicates that the test solenoid valve has not deteriorated significantly.

[0126] Step 2: Diagnosis of hydraulic control regulating valves

[0127] Step 21: Measurement of the effective working area of ​​the hydraulic piston

[0128] Install tension / compression sensors, ensuring the spring force and cylinder force are perpendicular to the sensor's working surface; install a displacement sensor between the cylinder drive rod and the cylinder mounting base; replace the servo valve with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while blocking the return pipe. The diagnostic device output pressure slightly increases the pressure of the testing device (generally less than 0.1 bar), and the tension / compression sensors change synchronously (see appendix). Figure 13 The displacement sensor displacement remains constant (displacement less than 0.1 mm), see attached. Figure 14 It can be calculated:

[0129] Unit: mm 2

[0130] Step 22: Measurement of valve operating resistance, spring strength, and valve sealing force

[0131] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see typical hydraulic control valve actuator circuit diagram). The servo valve is replaced with a dedicated module that allows the supply oil pipe to communicate with the oil chamber while blocking the return oil pipe. The diagnostic device establishes safety oil (see typical hydraulic control valve actuator circuit diagram). The diagnostic device slowly outputs a linearly increasing oil pressure at its supply port, gradually opening the valve until it is fully open. Subsequently, the diagnostic device slowly and linearly decreases the oil pressure at its supply port, gradually closing the valve until the oil pressure and displacement are zero. This process corresponds to the attached diagram. Figure 15 The curve shown illustrates the process. Pressure increases begin at point 0, gradually overcoming spring force and resistance. At point 1, the valve begins to open. At point 2, the valve is fully open, and pressure continues to rise to point 3. Pressure then begins to decrease, starting at point 4 and closing. At point 5, the valve is fully closed, and pressure continues to drop until it reaches zero, returning to point 0.

[0132] Through append Figure 16 The valve's operating resistance can be calculated from the oil pressure values ​​of curves 12 and 45. This is done by multiplying the oil pressure values ​​on the same horizontal axis (for the same valve position) of curves 12 and 45 by the effective operating area A, subtracting the result, and dividing by two. Figure 16 The valve's operating resistance curve is not actually a curve with a zero slope. It is obtained by linear fitting to form an average resistance curve with a zero slope. (See...) Figure 16 Double-dotted line.

[0133] Through append Figure 16 The spring strength can be calculated from the characteristic points 11, 12, 21, and 22 where vertical lines 1 and 2 intersect the 12-curve and the 45-curve.

[0134] Unit: N / mm

[0135] Through append Figure 16 The oil pressure corresponding to feature point 5 at the end of the 45° curve can be used to calculate the valve sealing force.

[0136] Unit: N

[0137] Step 23: Measurement of internal leakage of hydraulic unit (leakage from unloading valve and piston)

[0138] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The servo valve is replaced with a dedicated module that allows the supply oil pipe to communicate with the oil chamber while blocking the return oil pipe. The diagnostic device establishes safety oil (see schematic diagram of a typical hydraulic control valve actuator), and the diagnostic device slowly outputs a linearly increasing oil pressure at the supply port, gradually opening the valve until it is fully open. (See attached diagram.) Figure 17 , 18 As the oil pressure gradually rises, it primarily overcomes the spring force and friction. After reaching point 1, the valve begins to open, reaching full opening at point 2. The oil pressure then continues to rise, stopping at point 3. During this process, the oil volume in the hydraulic actuator initially increases rapidly from point 0 to point 1. Subsequently, as the valve gradually opens, the oil pressure begins to decrease until the valve is fully open. The leakage at point 2 represents the internal leakage of the hydraulic system, specifically the leakage from the unloading valve and piston. Figure 17 The middle part is Q-leaking.

[0139] Step 24: Evaluation of pressure chamber sealing performance

[0140] The diagnostic device establishes safety oil (typical hydraulic control valve actuator circuit diagram); the pressure sensor is connected to pressure tap 1 (typical hydraulic control valve actuator circuit diagram); the servo valve is replaced with a dedicated module that allows the supply oil line to communicate with the oil chamber while blocking the return oil line; the diagnostic device outputs a supply oil pressure of 1.25 times the operating pressure to P1, maintains the P1 pressure for 3 minutes, closes the supply oil line and safety oil line isolation valve, and can collect data such as... Figure 10 The oil pressure change trend curve shown, with a holding pressure T1, allows us to obtain the pressure chamber leakage rate.

[0141] Unit: bar / s

[0142] During the pressure test, leaks can be checked at sealed parts such as external interfaces and modules.

[0143] Step 25: Servo Valve Control Performance Evaluation

[0144] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device's signal output cable is connected to the servo valve. The diagnostic device establishes safety oil (see schematic diagram of a typical hydraulic control valve actuator), and switches the oil supply to a constant pressure state at the operating pressure. The diagnostic device outputs a linearly increasing signal to the servo valve, causing the oil pressure in the oil chamber to rise linearly, as shown in the attached diagram. Figure 20 Simultaneously, the valve opens non-linearly, and the displacement-oil pressure curve is as follows: Figure 21Subsequently, the diagnostic device outputs a linearly decreasing signal to the servo valve; the diagnostic device also outputs a non-linearly increasing signal to the servo valve, causing the valve to open linearly, such as... Figure 22 Subsequently, the diagnostic device outputs a non-linear decreasing signal to the servo valve, causing the valve to close linearly. Throughout the process, the on-site measured signal-oil pressure curve, oil pressure-displacement curve, and attached... Figure 1 If the slopes of the upward and downward displacement lines are similar and the oil pressure curves are similar (the Euclidean distance is similar, which will not be elaborated here), it indicates that the servo valve control performance has not deteriorated significantly.

[0145] Step 26: Measure the internal leakage of the servo valve under different valve position states.

[0146] A displacement sensor is installed between the moving and stationary parts of the switching valve to ensure that they move linearly relative to each other when the valve actuates. A pressure sensor is connected to pressure tap 1 (see schematic diagram of a typical hydraulic control valve actuator). The diagnostic device's signal output cable is connected to the servo valve. The diagnostic device establishes a safety oil supply (see schematic diagram of a typical hydraulic control valve actuator), and switches the oil supply to a constant pressure state. The diagnostic device outputs a non-linear rising signal to the servo valve, causing the valve to open linearly and maintain the valve position for 15 seconds. The diagnostic device measures the internal leakage of the servo valve under stable conditions at each valve position and plots a similar value. Figure 21 The line segment shown is used to measure the internal leakage of the servo valve at various displacement platforms.

[0147] By measuring the differences in various parameters and the slopes or shapes of various curves through the above-described implementation methods, it is possible to evaluate and analyze whether the state of the equipment before and after repair is consistent. With the increase of test records, continuous monitoring of the performance of similar or identical equipment can identify any minor deterioration, thereby achieving the purpose of early warning of equipment failure.

Claims

1. A method for on-site performance diagnosis of a hydraulic control valve, characterized in that, Includes the following steps: Step 1: Diagnostic examination of the hydraulic control switching valve; Step 1 includes the following steps: Step 11: Measure the effective working area of ​​the hydraulic cylinder piston; Step 11 involves installing tension and compression sensors, ensuring that the spring force and the hydraulic cylinder force are perpendicular to the working surface of the tension and compression sensors, and installing a displacement sensor between the hydraulic cylinder drive rod and the hydraulic cylinder fixed seat. The diagnostic device outputs pressure to slightly increase the pressure of the test device, causing the tension and compression sensors to change synchronously, while the displacement sensor maintains a constant displacement. Step 12: Valve fast closing time measurement; Step 12 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that they move in a straight line relative to each other when the valve operates. A safety oil level is established using a diagnostic device. The valve opens, and the diagnostic device simulates a real shut-off function, rapidly releasing the safety oil and quickly closing the valve. After a delay, the diagnostic device establishes the safety oil level again, opens the valve, simulates a real shut-off function, rapidly releasing the safety oil, and quickly closing the valve again. The quick-closing time T is then calculated. 快 ; Step 13: Measure valve operating resistance, spring strength, and valve sealing force; Step 13 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that the two parts move linearly relative to each other when the switching valve is activated. The pressure sensor is connected to pressure tap 1. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, causing the valve to gradually open until it is fully open. Subsequently, the oil supply port of the diagnostic device slowly and linearly decreases the oil pressure, causing the valve to gradually close until the oil pressure and displacement are zero. The valve's operating resistance is calculated, and the valve's operating resistance curve is obtained. By linear fitting, an average resistance curve with a slope of zero is obtained. The spring strength is calculated, and the valve's sealing force is calculated. Step 14: Measurement of internal leakage in the hydraulic device; Step 14 involves installing a displacement sensor between the moving and stationary parts of the switching valve to ensure that the two parts move linearly relative to each other when the switching valve is activated. The pressure sensor is connected to pressure tap 1. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, causing the valve to gradually open until it is fully open. Step 15: Evaluation of the sealing performance of the pressure chamber; Step 15 establishes safety oil for the diagnostic device. The pressure sensor is connected to pressure tap 1. The diagnostic device outputs oil pressure 1.25 times the operating pressure to a certain pressure, maintains the pressure for 3 minutes, closes the oil supply line and the isolation valve of the safety oil line, collects the oil pressure change trend curve, maintains the pressure, and obtains the pressure chamber leakage rate. During the pressure test, leakage is checked on the external interface and the sealing parts of the module. Step 16: Evaluation of the action performance of the hydraulic control switching valve; Step 16 involves installing a displacement sensor between the moving and stationary parts of the hydraulic control switch valve to ensure that the two parts move in a linear fashion when the hydraulic control switch valve is activated. A pressure sensor is connected to pressure tap 1. The diagnostic device signal output cable is connected to the switch valve. The diagnostic device establishes safety oil. The diagnostic device slowly outputs a linearly increasing oil pressure from its oil supply port. The valve gradually opens until it is fully open. The diagnostic device outputs an energized signal to the switch valve. The valve gradually closes until it is fully closed. The oil pressure drops to zero. The switch valve remains energized. The diagnostic device outputs a de-energized signal to the switch valve. The valve gradually opens from the closed state to the fully open state. The oil pressure gradually rises from zero to the working oil pressure. Step 2: Diagnose the hydraulic control regulating valve.

2. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 1, characterized in that, Step 2 includes the following: Step 21: Measure the effective working area of ​​the hydraulic cylinder piston; Step 22: Measurement of valve operating resistance, spring strength, and valve sealing force; Step 23: Measurement of internal leakage of the hydraulic device; Step 24: Evaluation of the sealing performance of the pressure chamber; Step 25: Evaluation of the control performance of the hydraulic control regulating valve; Step 26: Measure the internal leakage of the hydraulic control regulating valve under different valve position states.

3. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 21 involves installing tension and compression sensors, ensuring that the spring force and cylinder force are perpendicular to the action surface of the tension and compression sensors, installing a displacement sensor between the cylinder drive rod and the cylinder mounting base, replacing the hydraulic control regulating valve with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while the return pipe is blocked, and using the output pressure of the diagnostic device to slightly increase the pressure of the test device. The tension and compression sensors change synchronously, while the displacement sensor displacement remains constant. The effective action area A is then calculated.

4. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 22 involves installing a displacement sensor between the moving and stationary parts of the hydraulic control valve to ensure that they move linearly relative to each other when the hydraulic control valve operates. A pressure sensor is connected to pressure tap 1. The hydraulic control valve is replaced with a dedicated module that allows the oil supply pipe to communicate with the oil chamber while the return pipe is blocked. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, gradually opening the valve until it is fully open. Subsequently, the oil supply port of the diagnostic device slowly and linearly decreases the oil pressure, gradually closing the valve until the oil pressure and displacement are zero. The valve operating resistance is calculated, and an average resistance curve with a slope of zero is obtained by linear fitting. The spring strength and valve sealing force are then calculated.

5. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 23 involves installing a displacement sensor between the moving and fixed parts of the hydraulic control regulating valve to ensure that the two parts move in a linear fashion when the hydraulic control regulating valve is activated. A pressure sensor is connected to pressure tap 1. The hydraulic control regulating valve is replaced with a special module that allows the oil supply pipe to communicate with the oil chamber and the return pipe to be blocked. The diagnostic device establishes safety oil, and the oil supply port of the diagnostic device slowly outputs a linearly increasing oil pressure, causing the valve to gradually open until it is fully open.

6. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 24 involves establishing a safety oil supply for the diagnostic device, connecting the pressure sensor to pressure tap 1, replacing the hydraulic control regulating valve with a dedicated module that allows the oil supply line to communicate with the oil chamber while the return line is blocked, and having the diagnostic device output an oil supply pressure of 1.25 times the operating pressure to a certain pressure. This pressure is maintained for 3 minutes, and the isolation valves of the oil supply line and safety oil line are closed. The oil pressure change trend curve is collected, and the pressure is maintained to obtain the pressure chamber leakage rate. During the pressure test, leak checks are performed on the external interfaces and the sealing parts of the module.

7. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 25 involves installing a displacement sensor between the moving and stationary parts of the hydraulic control valve to ensure that they move linearly relative to each other when the hydraulic control valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device's signal output cable is connected to the hydraulic control valve. The diagnostic device establishes safety oil and switches its oil supply to a constant operating pressure. The diagnostic device outputs a linearly increasing signal to the hydraulic control valve, causing the oil pressure in the oil chamber to rise linearly, while the valve opens non-linearly. Subsequently, the diagnostic device outputs a linearly decreasing signal to the hydraulic control valve. The diagnostic device also outputs a non-linearly increasing signal to the hydraulic control valve, causing the valve to open linearly, followed by a non-linearly decreasing signal.

8. The method for on-site performance diagnosis of a hydraulic control valve as described in claim 2, characterized in that: Step 26 involves installing a displacement sensor between the moving and stationary parts of the hydraulic control valve to ensure that they move in a straight line relative to each other when the hydraulic control valve operates. A pressure sensor is connected to pressure tap 1. The diagnostic device's signal output cable is connected to the hydraulic control valve. The diagnostic device establishes safety oil and switches its oil supply to a constant pressure state. The diagnostic device outputs a non-linear rising signal to the hydraulic control valve, causing the valve to open linearly and maintain the valve position for 15 seconds. The diagnostic device measures the internal leakage of the hydraulic control valve under stable conditions at each valve position and plots the measured internal leakage line segment on each displacement platform.

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