A flow control method and system based on a conical spool pilot valve

Abstract

The application discloses a kind of flow control method and system based on conical valve core pilot valve, belong to the technical field of valve flow control, according to working condition, carry out quick pressure regulating or stable pressure regulating or intelligent pressure regulating.The quick pressure regulating: first, empty the water in the pilot upper cavity, so that the pilot valve reaches minimum opening, and the pilot valve core differential pressure is maximum;By controlling the water injection speed of the pilot upper cavity, the pressure of the main pressure reducing valve upper cavity is quickly reduced.The stable pressure regulating: first, fill the pilot upper cavity with water, so that the pilot valve quickly reaches maximum opening;By controlling the drainage speed of the pilot upper cavity, the pilot valve core differential pressure slowly rises.The intelligent pressure regulating: based on the differential pressure between the real-time pressure after the current main pressure reducing valve and the target pressure after the main pressure reducing valve, the water injection speed or drainage speed of the pilot upper cavity is controlled by using quick pressure regulating or stable pressure regulating method.The application can meet the needs of different working conditions, and realizes the intelligentization and diversification of pressure regulating process.

Description

Technical Field

[0001] This invention belongs to the technical field of valve flow control, specifically relating to a flow control method and system based on a conical valve core pilot valve. Background Technology

[0002] Pilot control is a hydraulic control technology that uses pilot valve pressure regulation to actuate the main valve. Its core principle is to establish a low-pressure control pressure using an external or internal fluid source (such as water or oil), driving the main valve spool to adjust system flow or pressure. Typical applications include electro-hydraulic directional valves and in-line pressure control valves. External control requires an independent fluid supply system, while internal control directly utilizes the main hydraulic circuit pressure. The structural design often employs pressure differential to drive the valve spool. The pilot valve spool senses the pressure difference and drives the axial sliding of the valve spool, working in conjunction with sealing components and adjustment mechanisms to ensure control accuracy and stability.

[0003] Specifically, existing pilot-operated pressure reducing valves are hydraulic or pneumatic control components that control the operation of the main pressure reducing valve through changes in the pressure of the pilot chamber. They are widely used in industrial automation, construction machinery, and hydraulic support systems in coal mines. The core advantage of pilot-operated pressure reducing valves lies in using a small-flow pilot signal to adjust the large-flow output pressure of the main pressure reducing valve, thereby achieving precise control of the system pressure. However, the existing flow control modes based on pilot-operated pressure reducing valves are relatively simple, and the flow area of ​​the valve core in existing pilot-operated pressure reducing valves exhibits non-linear characteristics, further reducing the accuracy of pressure regulation and making it unable to flexibly cope with complex and changing scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a flow control method and system based on a conical valve core pilot valve, which aims to solve the above-mentioned problems.

[0005] This invention is mainly achieved through the following technical solutions:

[0006] A flow control method based on a conical valve core pilot valve, which can perform rapid pressure regulation, stable pressure regulation, or intelligent pressure regulation according to the operating conditions;

[0007] The rapid pressure regulation is as follows: First, the water in the upper pilot chamber is drained, so that the pilot valve reaches its minimum opening and the pilot valve core pressure difference is maximized; by controlling the water injection speed in the upper pilot chamber, the pressure in the upper chamber of the main pressure reducing valve is rapidly reduced, and the opening of the main pressure reducing valve is rapidly increased, so as to rapidly reduce the outlet pressure of the main pressure reducing valve.

[0008] The pressure stabilization process involves: first, filling the upper pilot chamber with water to quickly bring the pilot valve to its maximum opening; then, by controlling the drainage rate of the upper pilot chamber, slowly increasing the pressure difference in the pilot valve core, slowly increasing the pressure in the upper chamber of the main pressure reducing valve, and slowly decreasing the opening of the main pressure reducing valve to gradually adjust the outlet pressure of the main pressure reducing valve.

[0009] The intelligent pressure regulation: Based on the pressure difference between the real-time pressure after the main pressure reducing valve and the target pressure after the main pressure reducing valve, the water injection speed or drainage speed of the pilot upper cavity is controlled by means of rapid pressure regulation or stable pressure regulation.

[0010] To better realize the present invention, the rapid voltage regulation further includes the following steps:

[0011] Step S1: Drain the water from the pilot cavity;

[0012] Step S2: Close the drain solenoid valve of the pilot upper cavity and open the water injection solenoid valve to inject water into the pilot upper cavity until:

[0013] ;

[0014] in: The real-time downstream pressure of the main pressure reducing valve;

[0015] The target pressure downstream of the main pressure reducing valve;

[0016] The set threshold;

[0017] Step S3: Estimate the total flow rate of the valve based on the inlet volume in the pilot upper cavity.

[0018] To better realize the present invention, further, in step S2, the single opening time of the water injection solenoid valve is... for:

[0019] ;

[0020] in: This is the minimum downstream pressure of the main pressure reducing valve when the pilot upper chamber is emptied and filled with water;

[0021] This is the minimum operating cycle time of the solenoid valve;

[0022] This is the maximum multiple of the minimum operating time cycle of the solenoid valve;

[0023] This is the threshold value for the minimum operating cycle of the solenoid valve.

[0024] To better realize the present invention, the voltage stabilization further includes the following steps:

[0025] Step T1: Fill the upper cavity of the pilot tube with water;

[0026] Step T2: Close the water injection solenoid valve of the pilot upper cavity and open the drain solenoid valve to control the drainage of the pilot upper cavity until:

[0027] ;

[0028] in: The real-time downstream pressure of the main pressure reducing valve;

[0029] The target pressure downstream of the main pressure reducing valve;

[0030] The set threshold;

[0031] Step T3: Estimate the total flow rate of the valve based on the drainage volume in the upper cavity of the pilot valve.

[0032] To better realize the present invention, further, in step T2, the single opening time of the drain solenoid valve is:

[0033] ;

[0034] in: The pressure before the main pressure reducing valve;

[0035] This is the minimum operating cycle time of the solenoid valve;

[0036] This is the maximum multiple of the minimum operating time cycle of the solenoid valve;

[0037] The threshold for the minimum operating cycle of the solenoid valve

[0038] The real-time downstream pressure of the main pressure reducing valve;

[0039] The target pressure downstream of the main pressure reducing valve.

[0040] To better realize the present invention, the intelligent voltage regulation further includes the following steps:

[0041] Step P1: Calculate the pressure difference between the current real-time downstream pressure of the main pressure reducing valve and the target downstream pressure of the main pressure reducing valve. :

[0042] ;

[0043] in: The real-time downstream pressure of the main pressure reducing valve;

[0044] The target pressure downstream of the main pressure reducing valve;

[0045] Step P2: If If so, no adjustment is needed; otherwise:

[0046] like Then record the current time t. n , and if Then proceed to step P3;

[0047] like Then record the current time t. n , and if Then proceed to step P4;

[0048] in: The set threshold;

[0049] The leakage rate of the pilot upper cavity;

[0050] The threshold percentage for allowing cumulative leakage;

[0051] This represents the maximum volume of the pilot cavity;

[0052] This refers to the moment when the last voltage regulation was completed.

[0053] This is the time to prepare for pressure adjustment;

[0054] Step P3: Perform rapid voltage adjustment and proceed to step P5;

[0055] Step P4: Perform voltage stabilization and proceed to step P5;

[0056] Step P5: Estimate the total flow rate of the valve based on the volume of water entering and exiting the pilot chamber.

[0057] To better implement the present invention, the estimation of the total flow rate of the valve further includes the following steps:

[0058] Step A1: Determine the action time of the solenoid valve in the pilot upper chamber and calculate the inlet and outlet water volumes in the pilot upper chamber;

[0059] Step A2: Based on the inlet and outlet water volumes of the solenoid valve, calculate the stroke of the pilot valve and determine the opening degree of the conical valve core;

[0060] Step A3: Calculate the flow area of ​​the pilot valve based on the opening degree of the conical valve core;

[0061] Step A4: Calculate the pressure in the upper chamber of the main pressure reducing valve based on the relationship between the flow area of ​​the pilot valve and the pressure difference;

[0062] Step A5: Based on the pressure in the upper chamber of the main pressure reducing valve, calculate the compression stroke of the main pressure reducing valve spring, and then determine the flow area of ​​the main pressure reducing valve;

[0063] Step A6: Calculate the flow rate of the main pressure reducing valve based on the flow area of ​​the main pressure reducing valve and the pressures before and after the valve. ; and then calculate the total flow rate of the valve. ;

[0064] in: This represents the flow rate in the pilot valve passage.

[0065] To better realize the present invention, further, in step A1, the inflow and outflow water volumes in the pilot upper cavity are:

[0066] ;

[0067] ;

[0068] in: The inflow and outflow volume within the minimum operating time period;

[0069] For the correction factor of influent and effluent;

[0070] This is the minimum operating time cycle of the solenoid valve;

[0071] The inlet and outlet water flow rates of the pilot upper cavity;

[0072] This refers to the inner diameter of the pipe.

[0073] The pressure before the main pressure reducing valve;

[0074] Standard atmospheric pressure;

[0075] For fluid density;

[0076] The length of the pipe;

[0077] This is the frictional resistance coefficient along the friction path.

[0078] To better realize the present invention, further, in step A1, the inflow and outflow water volumes in the pilot upper cavity are:

[0079] ;

[0080] ;

[0081] in: The inlet and outlet water volumes after the nth pressure stabilization;

[0082] The volume of water entering and exiting after the (n-1)th pressure stabilization is denoted as .

[0083] The inlet and outlet water flow rates of the pilot upper cavity after the nth pressure stabilization;

[0084] This represents the minimum operating time period of the solenoid valve after the nth voltage stabilization.

[0085] The pressure before the main pressure reducing valve;

[0086] Standard atmospheric pressure;

[0087] The Hooke's constant of the spring under pilot conditions;

[0088] S u This is the equivalent area of ​​the upper diaphragm;

[0089] This refers to the inner diameter of the pipe.

[0090] For fluid density;

[0091] The length of the pipe;

[0092] This is the frictional resistance coefficient along the friction path.

[0093] To better realize the present invention, furthermore, when the initial control or leakage requires correction, stable pressure regulation is performed during peak water usage periods, and rapid pressure regulation is performed during off-peak water usage periods; when the pressure is adjusted again and no correction is required, intelligent pressure regulation is performed.

[0094] A flow control system based on a conical valve core pilot valve, implemented based on the above-mentioned flow control method based on a conical valve core pilot valve, includes a fast pressure regulating module, a stable pressure regulating module, an intelligent pressure regulating module, and a flow prediction module;

[0095] The rapid voltage adjustment module is used to rapidly adjust the voltage according to the operating conditions;

[0096] The voltage stabilization module is used to stabilize and regulate voltage according to operating conditions.

[0097] The intelligent voltage regulation module is used to intelligently regulate the voltage according to the operating conditions.

[0098] The flow prediction module is used to estimate the total flow of valves that offer rapid pressure regulation, stable pressure regulation, or intelligent pressure regulation.

[0099] The beneficial effects of this invention are as follows:

[0100] (1) Based on a dynamic pressure regulation strategy, this invention constructs three modes: rapid pressure regulation, stable pressure regulation, and intelligent pressure regulation. These modes can adapt to different operating conditions, realizing the intelligent and diversified nature of the pressure regulation process and improving the robustness of the system. Based on the intelligent flow estimation method using fluid dynamics and geometric parameters, this invention achieves accurate quantification of total flow for the first time, providing data-driven decision-making capabilities for complex systems. Specifically, in practical applications, the pressure regulation mode can be flexibly selected according to different situations such as initial pressure regulation, leakage correction requirements, and peak and off-peak water usage periods. This maximizes the satisfaction of pressure regulation requirements under complex operating conditions and improves the system's operating efficiency and reliability.

[0101] (2) This invention achieves dynamic, precise, and adaptive control of system pressure by combining fluid pressure monitoring technology with pressure regulation records (such as the opening time of inlet and outlet solenoid valves). During initial pressure regulation or leakage correction, stable pressure regulation is implemented during peak periods, and rapid pressure regulation is implemented during off-peak periods; when no correction is required, intelligent pressure regulation is implemented, improving the ability to flexibly adapt flow control according to operating conditions. This invention, through the deep integration of multi-physics coupling modeling, dynamic pressure regulation strategies, and intelligent flow estimation systems, constructs a system-level intelligent control for pressure control and flow management that is adaptable to complex operating conditions, has low energy consumption, and high precision.

[0102] (3) By draining the water from the upper chamber of the pilot valve, the pilot valve quickly reaches its minimum opening, and the pressure difference of the pilot valve core is maximized. This causes the pressure in the upper chamber of the main pressure reducing valve to decrease rapidly, and the opening of the main pressure reducing valve to increase rapidly, thereby achieving rapid pressure regulation and a rapid decrease in outlet pressure. This mode is suitable for emergency situations that require rapid adjustment of system pressure. It can adjust the system pressure to the target value in a short time and improve the system's response speed. For example, it is suitable for emergency pressure relief or sudden working conditions.

[0103] (4) This invention fills the upper pilot chamber with water and then slowly drains it, causing a gradual change in the pressure difference of the pilot valve core. This allows for gradual adjustment of the pressure and opening of the upper chamber of the main pressure reducing valve, and by slowly adjusting the pilot valve opening, the opening of the main pressure reducing valve is gradually reduced. This achieves stable pressure regulation and ensures system stability during peak water usage periods and other high-flow-rate conditions. This mode is suitable for operating conditions with high system stability requirements, such as during peak water usage periods. It ensures that the system pressure remains stable during adjustment, preventing pressure fluctuations from damaging the equipment.

[0104] (5) Based on historical pressure regulation data and real-time monitoring (such as leakage compensation), this invention automatically determines whether drainage or water injection is needed, achieving intelligent pressure regulation and adaptive adjustment without manual intervention (suitable for long-term operation or complex fluctuation scenarios). Specifically, after the previous pressure regulation is completed, if no correction is needed, the pilot upper cavity is intelligently controlled to drain or inject water according to the current cavity pressure. When the pilot upper cavity drains to a certain extent, the correction mechanism is automatically triggered. This intelligent pressure regulation method can automatically adjust the pressure regulation strategy according to the actual operation of the system, improving the system's adaptability and intelligence level.

[0105] (6) This invention provides precise flow management and data-driven decision-making capabilities for scenarios such as smart water management and industrial automation. This invention derives the flow area by analyzing the pilot valve core position and geometry, and, combined with the pressure difference across the main pressure reducing valve and fixed design parameters (such as valve seat diameter and flow path length), estimates the flow rate in the main pressure reducing valve passage using Bernoulli's equation and the Darcy-Weisbach formula. Simultaneously, the flow rates in the main pressure reducing valve passage and the pilot passage are added together to obtain the total valve flow rate. This invention not only achieves real-time quantification of flow rate but also directly correlates flow rate with pressure, geometric parameters, and power source characteristics through mathematical modeling, providing a theoretical basis for dynamic system adjustment and fault early warning.

[0106] (7) This invention innovatively adopts a conical valve core design, deeply integrating fluid mechanics principles with mechanical geometric characteristics. From a fluid mechanics perspective, the conical shape makes the flow field distribution more uniform and reasonable when the fluid passes through the valve core, effectively reducing turbulence and energy loss at the valve core and improving the flow efficiency of the fluid. Compared with traditional valve cores, the conical valve core design of this invention fundamentally solves the problem of inaccurate pressure regulation caused by nonlinear flow area, providing a solid structural foundation for high-precision pressure control.

[0107] (8) Based on Bernoulli's equation and Darcy-Weisbach's formula in fluid mechanics, and combined with the recording of the opening time of the inlet and outlet solenoid valves in the mode adjustment, this invention establishes a precise flow estimation method. By calculating the flow velocity of the cavity drainage and water injection, and combining the opening time of the inlet and outlet solenoid valves, the volume of the upper pilot chamber is accurately calculated. The position of the pilot valve core is determined based on the volume of the upper pilot chamber (leakage compensation is introduced during intelligent pressure regulation), and the flow area of ​​the valve core is determined by combining the position and geometry of the pilot valve core. This invention accurately determines the flow rate of the pilot valve passage and the pressure of the upper chamber of the main pressure reducing valve by using the flow area of ​​the pilot valve, the pressure before and after the valve, and fixed design parameters. Then, the flow area of ​​the main pressure reducing valve is determined based on the pressure of the upper chamber of the main pressure reducing valve and the valve core parameters of the main pressure reducing valve. Finally, the flow rate of the main pressure reducing valve passage is determined by the flow area of ​​the main pressure reducing valve and the pressure difference before and after. The sum of the main (pressure reducing) valve passage and the pilot passage is the total valve flow rate. Attached Figure Description

[0108] Figure 1 This is a schematic diagram of the connection structure between the pilot valve and the main pressure reducing valve.

[0109] Figure 2 A schematic diagram of the valve plug for a conical valve core;

[0110] Figure 3 This is a schematic diagram of the flow control system based on a conical valve core pilot valve according to the present invention.

[0111] Wherein: 100-pilot valve, 200-main pressure reducing valve, 201-upper chamber of main pressure reducing valve, 202-main pressure reducing valve chamber, 203-pressure reducing valve core. Detailed Implementation

[0112] Example 1:

[0113] A flow control system based on a conical valve core pilot valve, such as Figure 3 As shown, it includes a fast voltage regulation module, a stable voltage regulation module, an intelligent voltage regulation module, and a flow prediction module;

[0114] The rapid pressure regulating module discharges water from the upper chamber of the pilot valve, causing the pilot valve 100 to quickly reach its minimum opening. At this point, the pressure difference in the pilot valve 100 core is at its maximum, increasing the pressure in the upper chamber 201 of the main pressure reducing valve. As the pressure difference in the pilot valve 100 core rapidly decreases, the pressure in the upper chamber 201 of the main pressure reducing valve rapidly decreases, and the opening of the main pressure reducing valve 200 rapidly increases, thus achieving the purpose of rapid pressure regulation.

[0115] The pressure stabilization module fills the upper pilot chamber with water, causing the pilot valve 100 to quickly reach its maximum opening, draining the upper pilot chamber. As the opening of the pilot valve 100 decreases, the pressure difference of the pilot valve 100 core slowly increases, the upper chamber 201 of the main pressure reducing valve slowly increases, and the opening of the main pressure reducing valve 200 slowly decreases, thus achieving the purpose of stabilizing pressure.

[0116] Among them, the intelligent pressure regulating module, after the previous pressure regulation is completed, if no correction is required, will intelligently determine based on the current cavity pressure and first guide the upper cavity to drain or inject water; the correction condition is that the water in the upper cavity leaks to a certain extent.

[0117] Module selection: When correction is needed for the first time or due to leakage, the stable pressure regulating module is activated during peak water usage periods (to ensure water supply); when correction is needed for the first time or due to leakage, the fast pressure regulating module is activated during off-peak water usage periods; when pressure is regulated again and correction is not required, the intelligent pressure regulating module is activated.

[0118] Preferably, such as Figure 1As shown, the pilot valve 100 includes a conical valve core, a valve body, an upper diaphragm, and a lower diaphragm. The valve body includes a pilot upper cavity, an atmospheric cavity, and a pilot cavity arranged sequentially from top to bottom. The atmospheric cavity is connected to the atmosphere. The conical valve core is disposed inside the pilot cavity. The upper diaphragm and the lower diaphragm are slidably disposed between the pilot upper cavity and the atmospheric cavity, and between the atmospheric cavity and the pilot cavity, respectively. A pilot upper spring with a large Hooke's coefficient (approximately rigid) is disposed between the upper and lower diaphragms. The conical valve core includes a valve seat and a valve plug. The valve plug has a conical structure. The top of the valve plug is connected to the lower diaphragm, and a pilot lower spring is disposed between the bottom of the valve plug and the pilot cavity.

[0119] Preferably, the main pressure reducing valve 200 includes an upper chamber 201, a body 202, and a pressure reducing valve core 203. The pressure reducing valve core 203 is disposed within the body 202. A diaphragm is disposed between the upper chamber 201 and the body 202, and a spring is disposed between the diaphragm and the upper chamber 201. The bottom of the diaphragm is connected to the valve plug of the pressure reducing valve core 203. The upper and lower chambers of the pilot chamber are respectively connected to the upper chamber 201 and the outlet of the main pressure reducing valve 200 via pipes. The inlet of the main pressure reducing valve 200 is connected to the upper chamber 201 and the pilot upper chamber via pipes. Solenoid valves are respectively disposed at the inlet and outlet ends of the pilot upper chamber.

[0120] According to the principle of energy conservation and Bernoulli's equation in fluid mechanics, the pressure at the convergence point of the main pipe and the bypass in a fluid system is equal. The law of equal pressure difference in parallel pipe systems states that in a parallel pipe system (i.e., fluid flows from a main pipe to multiple branch pipes and eventually returns to the main pipe), the pressure difference (ΔP) between the inlet and outlet of each branch pipe is equal, and also equal to the pressure difference before and after the branching in the main pipe. Therefore, the following holds:

[0121] The pressure balance formula for the main pressure reducing valve 200 is:

[0122] ;

[0123] in: Pressure loss in the main pressure reducing valve 200 circuit and the pilot valve 100 circuit;

[0124] : The pressure before the main pressure reducing valve 200;

[0125] : The pressure downstream of the main pressure reducing valve 200.

[0126] Pilot valve 100 pressure balance formula:

[0127] Setting: Since the cross-section of the upper pilot chamber of pilot valve 100 is much larger than the cross-section of the flow guide pipe of pilot valve 100, the pressure loss of the upper chamber 201 of the main pressure reducing valve due to flow is ignored. ,

[0128]

[0129] in: The dynamic pressure loss from the inlet of the main pressure reducing valve 200 to the upper chamber 201 of the main pressure reducing valve corresponds to the effective length of the pipeline. ;

[0130] The dynamic pressure loss from the upper chamber 201 of the main pressure reducing valve to the valve chamber of the pilot valve 100 corresponds to the effective length of the pipeline. ;

[0131] Dynamic pressure loss of the conical valve core;

[0132] The dynamic pressure loss from the pilot valve 100 valve chamber to the outlet of the main pressure reducing valve 200 corresponds to the effective pipeline length of: ;

[0133] The equivalent pipeline pressure loss of the main pressure reducing valve upper chamber 201 and pilot chamber is 0 by default.

[0134] This invention calculates the flow velocity of drainage or injection in the pilot upper cavity using Bernoulli's equation, the West-Weisbach formula, and mechanical equilibrium; calculates the volume of the pilot upper cavity using the drainage or injection flow velocity and the opening time of the solenoid valves at the inlet and outlet, thereby determining the position of the pilot valve 100 spool (intelligent pressure regulation requires leakage compensation); determines the flow area of ​​the pilot valve 100 spool using its position and geometry; determines the flow rate of the pilot valve 100 passage and the pressure of the main pressure reducing valve upper cavity 201 using the flow area of ​​the pilot valve 100 spool, the pressure before / after the valve, and fixed design parameters; determines the flow area of ​​the main pressure reducing valve 200 using the pressure of the main pressure reducing valve upper cavity 201 and the spool parameters of the main pressure reducing valve 200; determines the flow rate of the main pressure reducing valve 200 passage using the flow area of ​​the main pressure reducing valve 200 and the pressure difference before and after the valve; and the sum of the flow rate of the main pressure reducing valve 200 passage and the flow rate of the pilot valve 100 passage is the total valve flow rate.

[0135] Example 2:

[0136] A flow control method based on a conical valve core pilot valve for rapid pressure regulation includes the following steps:

[0137] Step 1: Preset the minimum valve opening of pilot valve 100;

[0138] Step 2: Drain the water from the pilot cavity;

[0139] Step 3: When the downstream pressure of the main pressure reducing valve 200 remains constant (the main pressure reducing valve 200 is preset to a minimum opening), close the drain solenoid valve and open the water injection solenoid valve to inject water into the upper pilot chamber; the time for each opening of the solenoid valve is as follows:

[0140] ;

[0141] in:

[0142] : The minimum downstream pressure (pressure) of the main pressure reducing valve 200 when the pilot upper cavity is emptied and water is injected.

[0143] The minimum operating cycle time of the solenoid valve;

[0144] The maximum multiple of the minimum operating time cycle of the solenoid valve;

[0145] The threshold value for the minimum operating cycle of the solenoid valve;

[0146] : Real-time downstream pressure (pressure) of main pressure reducing valve 200.

[0147] : The target pressure downstream of the main pressure reducing valve 200.

[0148] Step 4: After the water injection solenoid valve completes its operation, wait for a period of time (usually 30-120 seconds, default 60 seconds) until the system reaches equilibrium, then compare the pressure after the valve.

[0149] Step 5: If Then repeat steps 3 to 4;

[0150] like Then the voltage regulation ends, and the voltage regulation time te is recorded;

[0151] in: : The set threshold.

[0152] Step 6: Estimate the total flow rate of the valve;

[0153] Step 61: Count the number of times the water injection solenoid valve actuates, n, and the time of the i-th actuation is... Calculate the action time of the water injection solenoid valve;

[0154] ;

[0155] in: : The operating time of the water injection solenoid valve.

[0156] Step 62: Calculate the inlet volume of the solenoid valve;

[0157] Method 1) Low-computing-power fast estimation:

[0158] The minimum inlet and outlet water volumes generated by the solenoid valve on the pilot upper cavity under the design pressure are determined by Bernoulli's equation; based on the valve principle, the stroke of the upper diaphragm is determined by the volume of water discharged by the solenoid valve in the minimum action time period (the limit time of opening and closing); and then the inlet and outlet water velocities are calculated.

[0159] For incompressible fluids (such as liquids), neglecting elevation changes, Bernoulli's equation simplifies to:

[0160] ;

[0161] in: , These represent the flow velocities before and inside the pipe connected to the upper cavity of the pilot tube, respectively. If the pipe diameter remains constant, ;

[0162] The pressure before the main pressure reducing valve 200, i.e. ;

[0163] Standard atmosphere;

[0164] Friction loss along the friction path is calculated using the Darcy-Weisbach formula:

[0165] ;

[0166] Friction resistance coefficient along the pipe, which is related to the Reynolds number Re and the pipe wall roughness;

[0167] Fluid density;

[0168] : Length of the pipe (m);

[0169] : Inner diameter of the pipe (m);

[0170] : Inlet and outlet water flow velocity (m / s) of the pilot upper cavity. And the calculation formula is:

[0171] ;

[0172] Note: Water injection is continuous, and the injection speed decreases as the stroke progresses.

[0173] Example 1: The pressure before the valve is 1000 kPa (design maximum pressure), atmospheric pressure is 101.3 kPa, pipe diameter is 6 mm, equivalent pipe length (including bends, joints, valve body, etc.) is 20 m, water density is 1000 kg / m³, and equivalent friction coefficient is 0.5; substitute these values ​​into the formula to calculate the inlet and outlet flow velocities of the pilot upper cavity:

[0174] .

[0175] Example 2: The pressure before the valve is 450 kPa (actual working pressure), atmospheric pressure is 101.3 kPa, pipe diameter is 6 mm, equivalent pipe length (including equivalent bends, joints, valve body, etc.) is 20 m, water density is 1000 kg / m³, and equivalent friction coefficient is 0.5; substitute these values ​​into the formula to calculate the inlet and outlet water velocities of the pilot upper cavity:

[0176] The maximum inlet volume of the water injection solenoid valve is calculated as follows:

[0177] ;

[0178] in: Minimum operating time cycle (limited switching time) of the water injection solenoid valve.

[0179] : The volume of water entering the system within the minimum operating time period;

[0180] : Correction factor for water intake, default is 1.

[0181] Method 2) High-performance computing:

[0182] Each pressure adjustment causes a slight change in flow rate (which can be estimated to be negligible). The flow rate when the solenoid valve is first opened is:

[0183] ;

[0184] The volume of water injected after the first pressure stabilization is:

[0185] ;

[0186] The initial valve opening is:

[0187] The stroke generated by the upper diaphragm is as follows:

[0188] ;

[0189] ;

[0190] in: The first injection of water into the diaphragm creates the stroke;

[0191] : Equivalent diameter of the upper diaphragm;

[0192] S u This is the equivalent area of ​​the upper diaphragm;

[0193] And so on, the flow velocity generated in the nth iteration is:

[0194] ;

[0195] The volume of water injected after the nth pressure stabilization is:

[0196] .

[0197] in: The inlet water volume after the nth pressure stabilization;

[0198] The volume of water entering the system after the (n-1)th pressure stabilization.

[0199] The inlet and outlet water flow rates of the pilot upper cavity after the nth pressure stabilization;

[0200] The minimum operating time cycle of the water injection solenoid valve after the nth pressure stabilization;

[0201] The pressure before the main pressure reducing valve 200;

[0202] Standard atmospheric pressure;

[0203] The Hooke's constant of the spring under pilot conditions;

[0204] S u This is the equivalent area of ​​the upper diaphragm;

[0205] This refers to the inner diameter of the pipe.

[0206] For fluid density;

[0207] The length of the pipe;

[0208] This is the frictional resistance coefficient along the friction path.

[0209] Step 63: Calculate the stroke of pilot valve 100;

[0210] The stroke generated by the upper diaphragm is as follows:

[0211] ;

[0212] ;

[0213] in: : Equivalent diameter of the upper diaphragm;

[0214] Step 64: Calculate the flow area of ​​pilot valve 100;

[0215] ;

[0216] The relationship between L1 and L2 is as follows:

[0217] ;

[0218] in: for Figure 2 The cone surface area of ​​the cone formed by the virtual radius r1 shown;

[0219] for Figure 2 The area of ​​the cone surface formed by the virtual radius r2 shown;

[0220] The cone angle of the valve plug in a conical valve core;

[0221] The bottom diameter of the valve plug in a conical valve core;

[0222] The top diameter of the valve plug in a conical valve core;

[0223] : The cone height of the valve plug in a conical valve core;

[0224] : The opening degree of the conical valve core;

[0225] ;

[0226] : Minimum effective stroke of valve core.

[0227] The flow area is corrected to:

[0228] ;

[0229] in: Corrected flow area of ​​pilot valve 100;

[0230] : Correction factor for the flow area of ​​pilot valve 100, default value is 1.

[0231] Step 65: Calculate the pressure in the upper chamber 201 of the main pressure reducing valve;

[0232] Based on the relationship between the flow area of ​​the valve core and the pressure difference, we have:

[0233] ;

[0234] Where: ΔP 12 The difference between the upstream pressure P1 and the downstream pressure P2 of the main pressure reducing valve 200;

[0235] The valve core flow coefficient varies with the Reynolds number and is obtained through laboratory calibration or by referring to a table.

[0236] The flow coefficient of a small pipeline varies with the Reynolds number and is obtained through laboratory calibration or by referring to a table.

[0237] The cross-sectional area of ​​the valve core inlet is equivalent to the flow area of ​​a small pipe. ;

[0238] The cross-sectional area of ​​the valve core outlet is obtained from the 100-degree stroke of the pilot valve. ;

[0239] : Flow rate in branch pipes, and the flow rate is equal at all points in the branch;

[0240] Friction resistance coefficient along the pipe, which is related to the pipe wall roughness;

[0241] : Equivalent length of the pipeline (m) ;

[0242] : Inner diameter of the small pipe (m);

[0243] Fluid density (kg / m³).

[0244] Step 66: Calculate the compression stroke of the main pressure reducing valve spring;

[0245] ;

[0246] in: : Hooke's constant of the main pressure reducing valve spring;

[0247] : The pressure in the upper chamber 201 of the main pressure reducing valve;

[0248] Real-time downstream pressure of the main pressure reducing valve 200;

[0249] : The effective bearing area of ​​the diaphragm 201 in the upper chamber of the main pressure reducing valve;

[0250] : The pressure before the main pressure reducing valve 200;

[0251] : The flow area of ​​the main pressure reducing valve 200.

[0252] Step 67: Calculate the flow area of ​​the main pressure reducing valve 200:

[0253] The typical opening height of a concave (and cylindrical) valve core, which is the cylindrical area formed by the circumference and height of the through-hole, is:

[0254] ;

[0255] in: The diameter of the valve core of the main pressure reducing valve 200;

[0256] : The opening degree of the conical valve core;

[0257] : Equivalent coefficient of flow area, default 0.95 .

[0258] Step 68: Calculate the flow rate of the main pressure reducing valve 200 using the flow area of ​​the main pressure reducing valve 200 and the pressures before and after the valve;

[0259] ;

[0260] in: The flow coefficient of the main pressure reducing valve 200 valve core varies with the Reynolds number and is obtained by laboratory calibration or by referring to a table.

[0261] The flow coefficient of the main pressure reducing valve 200 pipeline varies with the Reynolds number and is obtained by laboratory calibration or by referring to a table.

[0262] : Main pressure reducing valve 200 pipeline flow area;

[0263] Main pressure reducing valve 200 flow rate;

[0264] Simplifying, we get:

[0265] ;

[0266] Therefore, the relationship between the flow rate of the branch pipe and the flow area of ​​the valve core is as follows:

[0267] ;

[0268] The total flow rate is:

[0269] .

[0270] Example 3:

[0271] A flow control method based on a conical valve core pilot valve for stable pressure regulation includes the following steps:

[0272] Step 1: Preset the minimum valve opening of pilot valve 100;

[0273] Step 2: Fill the upper cavity of the pilot tube with water;

[0274] Step 3: When the downstream pressure of the main pressure reducing valve 200 equals the upstream pressure, the main pressure reducing valve 200 reaches its maximum opening, closing the water injection solenoid valve and opening the drain solenoid valve. The single opening time of the solenoid valve is:

[0275] ;

[0276] in: : The pressure before the main pressure reducing valve 200;

[0277] The minimum operating cycle time of the solenoid valve;

[0278] The maximum multiple of the minimum operating time cycle of the solenoid valve;

[0279] The threshold value for the minimum operating cycle of the solenoid valve;

[0280] Real-time downstream pressure of the main pressure reducing valve 200;

[0281] : The target pressure downstream of the main pressure reducing valve 200.

[0282] Step 4: After the drain solenoid valve completes its operation, wait for a period of time (usually 30-120 seconds, default 60 seconds) until the system reaches equilibrium, then compare the pressure after the valve.

[0283] Step 5: If If so, repeat steps 3-4; Then the voltage regulation ends, and the voltage regulation time te is recorded;

[0284] in: : The set threshold.

[0285] Step 6: Estimate valve flow rate;

[0286] Step 61: Count the number of electromagnetic actions n and the time of each action. Calculate the action time of the drain solenoid valve;

[0287] ;

[0288] in: : The operating time of the drain solenoid valve;

[0289] Total number of solenoid valve actuations;

[0290] : Action time of a single drain solenoid valve;

[0291] Step 62: Calculate the drainage volume of the solenoid valve;

[0292] Method 1) Low-computing-power fast estimation:

[0293] Similarly to Example 2, calculate the maximum drainage volume of the drain solenoid valve:

[0294] ;

[0295] in: Minimum operating time cycle (limited switching time) of the drain solenoid valve.

[0296] The volume of water drained within the minimum action time period;

[0297] : Drainage correction factor, default 1.

[0298] Method 2) High-performance computing;

[0299] Similarly to Example 2, the volume of water injected after the nth pressure stabilization is:

[0300] .

[0301] in: The volume of water discharged after the nth pressure stabilization;

[0302] This represents the volume of water drained after the (n-1)th pressure stabilization.

[0303] The inlet and outlet water flow rates of the pilot upper cavity after the nth pressure stabilization;

[0304] This is the minimum operating time cycle of the drain solenoid valve after the nth pressure stabilization.

[0305] This refers to the inner diameter of the pipe.

[0306] Step 63: Calculate the stroke of pilot valve 100;

[0307] The stroke generated by the upper diaphragm is as follows:

[0308] ;

[0309] Wherein: S u This is the equivalent area of ​​the upper membrane.

[0310] Step 64: Calculate the flow area of ​​pilot valve 100;

[0311] Flow area The calculation formula for the flow area correction is the same as in Example 2, so it will not be repeated here; among them, the opening degree of the conical valve core for:

[0312] ;

[0313] in: : Maximum effective stroke of valve core.

[0314] Step 65: Calculate the pressure in the upper chamber 201 of the main pressure reducing valve;

[0315] Step 66: Calculate the main pressure reducing valve spring stroke:

[0316] Step 67: Calculate the flow area of ​​the main pressure reducing valve 200:

[0317] Step 68: Calculate the flow rate of the main pressure reducing valve 200 using the flow area of ​​the main pressure reducing valve 200 and the pressures before and after the valve;

[0318] The calculation principles of steps 64 to 68 are the same as those in Example 2, so they will not be repeated here.

[0319] Example 4:

[0320] A flow control method based on a conical valve core pilot valve for intelligent pressure regulation includes the following steps:

[0321] Step 1: If the valve reaches a stable value, record the current water injection volume V0 of the pilot upper cavity and the time t0;

[0322] Step 2: When the next time period arrives, if the system inlet pressure changes or the target outlet pressure of the main pressure reducing valve 200 changes, it is necessary to adjust the system by controlling the water injection solenoid valve and the drain solenoid valve. The specific steps are as follows:

[0323] Step 21: Calculate the pressure difference between the real-time downstream pressure of the main pressure reducing valve 200 and the target downstream pressure of the main pressure reducing valve 200:

[0324] ;

[0325] in: : Real-time downstream pressure (pressure) of main pressure reducing valve 200.

[0326] The target pressure downstream of the main pressure reducing valve 200;

[0327] Step 22: Compensate for the water injection volume of the pilot upper cavity;

[0328] Setting: 1) No sealing device can achieve an absolute seal, and leakage may occur over time; 2) In fluid mechanics, water is set as an incompressible liquid (ignoring the slight deformation of water), that is, leakage does not change the pressure of the water injection chamber.

[0329] Step 23: Determine whether the solenoid valve needs to be activated:

[0330] Step 231: If If so, the solenoid valve does not need to operate;

[0331] like Then record the current time t. n , and if If the condition is met, proceed to step 232 to enter the fast voltage regulation mode; otherwise, proceed to step 233 to enter the stable voltage regulation mode.

[0332] like (Main pressure reducing valve 200 preset minimum opening), record the current time t. n And if it exists: If the condition is met, proceed to step 232 to enter the fast voltage regulation mode; otherwise, proceed to step 233 to enter the stable voltage regulation mode.

[0333] in: : Leakage rate of the pilot upper cavity;

[0334] The threshold percentage for allowing cumulative leaks;

[0335] : The maximum volume of the pilot cavity;

[0336] The last time the voltage regulation was completed;

[0337] The current moment when pressure adjustment is about to begin.

[0338] Step 232: Fast voltage regulation mode;

[0339] Step 2321: Close the drain solenoid valve and open the water injection solenoid valve; the solenoid valve opening time for a single operation is... The calculation method is the same as in Example 2;

[0340] Step 2322: After the water injection solenoid valve completes its operation, wait for a period of time (usually 30-120 seconds, default 60 seconds) until the system reaches equilibrium, then compare the pressure after the valve.

[0341] Step 2323: If Repeat steps 2321 and 2322; if Then the voltage regulation ends.

[0342] Step 233: Stable voltage regulation mode;

[0343] Step 2331: Close the water injection solenoid valve and open the drain solenoid valve, with the single solenoid valve opening time being [time value missing]. ;

[0344] Step 2332: After the water injection solenoid valve completes its operation, wait for a period of time (usually 30-120 seconds, default 60 seconds) until the system reaches equilibrium, then compare the pressure after the valve.

[0345] Step 2333: If Repeat steps 2331 to 2332; if Then the voltage regulation ends.

[0346] Step 3: Estimate valve flow rate;

[0347] Step 31: Count the number of times the water injection solenoid valve is activated. Time of each action Calculate the action time of the water injection solenoid valve ;

[0348] Count the number of times the drain solenoid valve operates. Time of each action Calculate the valve action time of the drain solenoid valve ;

[0349] Step 32: Calculate the water volume in the pilot upper cavity;

[0350] The minimum inlet and outlet water volumes generated by the solenoid valve on the pilot upper cavity under the design pressure are determined by Bernoulli's equation; based on the valve principle, the stroke of the upper diaphragm is determined by the volume of water discharged by the solenoid valve in the minimum action time period (the limit time of opening and closing); and then the inlet and outlet water velocities are calculated.

[0351] The calculation principle is the same as in Example 2, calculating the ultimate total inlet and outlet water volume of the solenoid valve. :

[0352] ;

[0353] Step 33: Calculate the stroke of pilot valve 100 ;

[0354] Step 34: Calculate the flow area of ​​pilot valve 100;

[0355] Step 35: Calculate the main pressure reducing valve spring stroke;

[0356] Step 35: Calculate the flow area of ​​the main pressure reducing valve 200:

[0357] Step 36: Calculate the flow rate of the main pressure reducing valve 200 using the flow area of ​​the main pressure reducing valve 200 and the pressures before and after the valve;

[0358] The calculation principles of steps 33 to 36 are the same as those in Example 2, so they will not be repeated here.

[0359] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A flow control method based on a conical valve core pilot valve, characterized in that, Depending on the operating conditions, the voltage can be adjusted quickly, steadily, or intelligently. The rapid pressure regulation is as follows: First, the water in the upper pilot chamber is drained, so that the pilot valve reaches its minimum opening and the pilot valve core pressure difference is maximized; by controlling the water injection speed in the upper pilot chamber, the pressure in the upper chamber of the main pressure reducing valve is rapidly reduced, and the opening of the main pressure reducing valve is rapidly increased, so as to rapidly reduce the outlet pressure of the main pressure reducing valve. The pressure regulation is as follows: First, fill the upper chamber of the pilot valve with water so that the pilot valve can quickly reach its maximum opening. By controlling the drainage speed of the upper chamber of the pilot valve, the pressure difference of the pilot valve core increases slowly, the pressure in the upper chamber of the main pressure reducing valve increases slowly, and the opening of the main pressure reducing valve decreases slowly, so as to slowly regulate the outlet pressure of the main pressure reducing valve. The intelligent pressure regulation: Based on the pressure difference between the real-time pressure after the main pressure reducing valve and the target pressure after the main pressure reducing valve, the water injection speed or drainage speed of the pilot upper cavity is controlled by means of rapid pressure regulation or stable pressure regulation. The aforementioned rapid, stable, or intelligent pressure regulation based on operating conditions is as follows: when initial control or leakage correction is required, stable pressure regulation is performed during peak water usage periods, and rapid pressure regulation is performed during off-peak water usage periods; when pressure is adjusted again and no correction is required, intelligent pressure regulation is performed.

2. The flow control method based on a conical valve core pilot valve according to claim 1, characterized in that, The rapid voltage regulation includes the following steps: Step S1: Drain the water from the pilot cavity; Step S2: Close the drain solenoid valve of the pilot upper cavity and open the water injection solenoid valve to inject water into the pilot upper cavity until: ； in: The real-time downstream pressure of the main pressure reducing valve; The target pressure downstream of the main pressure reducing valve; The set threshold; Step S3: Estimate the total flow rate of the valve based on the inlet volume in the pilot upper cavity.

3. The flow control method based on a conical valve core pilot valve according to claim 2, characterized in that, In step S2, the single opening time of the water injection solenoid valve for: ； in: This is the minimum downstream pressure of the main pressure reducing valve when the pilot upper chamber is emptied and filled with water; This is the minimum operating cycle time of the solenoid valve; This is the maximum multiple of the minimum operating time cycle of the solenoid valve; This is the threshold value for the minimum operating cycle of the solenoid valve.

4. The flow control method based on a conical valve core pilot valve according to claim 1, characterized in that, The voltage stabilization and regulation includes the following steps: Step T1: Fill the pilot upper cavity with water; Step T2: Close the water injection solenoid valve of the pilot upper cavity and open the drain solenoid valve to control the drainage of the pilot upper cavity until: ； in: The real-time downstream pressure of the main pressure reducing valve; The target pressure downstream of the main pressure reducing valve; The set threshold; Step T3: Estimate the total flow rate of the valve based on the drainage volume in the upper cavity of the pilot valve.

5. The flow control method based on a conical valve core pilot valve according to claim 4, characterized in that, In step T2, the single opening time of the drain solenoid valve is: ； in: The pressure before the main pressure reducing valve; This is the minimum operating cycle time of the solenoid valve; This is the maximum multiple of the minimum operating time cycle of the solenoid valve; The threshold for the minimum operating cycle of the solenoid valve The real-time downstream pressure of the main pressure reducing valve; The target pressure downstream of the main pressure reducing valve.

6. The flow control method based on a conical valve core pilot valve according to claim 1, characterized in that, The intelligent voltage regulation includes the following steps: Step P1: Calculate the pressure difference between the current real-time downstream pressure of the main pressure reducing valve and the target downstream pressure of the main pressure reducing valve. : ； in: The real-time downstream pressure of the main pressure reducing valve; The target pressure downstream of the main pressure reducing valve; Step P2: If If so, no adjustment is needed; otherwise: like Then record the current time t. n , and if Then proceed to step P3; like Then record the current time t. n , and if Then proceed to step P4; in: The set threshold; The leakage rate of the pilot upper cavity; The threshold for the percentage of cumulative leakage allowed; This represents the maximum volume of the pilot cavity; This refers to the moment when the last voltage regulation was completed. Prepare for the current voltage adjustment; Step P3: Perform rapid voltage adjustment and proceed to step P5; Step P4: Perform voltage stabilization and proceed to step P5; Step P5: Estimate the total flow rate of the valve based on the volume of water entering and exiting the pilot chamber.

7. A flow control method based on a conical valve core pilot valve according to any one of claims 2-6, characterized in that, The process of estimating the total flow rate of the valve includes the following steps: Step A1: Determine the action time of the solenoid valve in the pilot upper chamber and calculate the inlet and outlet water volumes in the pilot upper chamber; Step A2: Based on the inlet and outlet water volumes of the solenoid valve, calculate the stroke of the pilot valve and determine the opening degree of the conical valve core; Step A3: Calculate the flow area of ​​the pilot valve based on the opening degree of the conical valve core; Step A4: Calculate the pressure in the upper chamber of the main pressure reducing valve based on the relationship between the flow area of ​​the pilot valve and the pressure difference; Step A5: Based on the pressure in the upper chamber of the main pressure reducing valve, calculate the compression stroke of the main pressure reducing valve spring, and then determine the flow area of ​​the main pressure reducing valve; Step A6: Calculate the flow rate of the main pressure reducing valve based on the flow area of ​​the main pressure reducing valve and the pressures before and after the valve. ; and then calculate the total flow rate of the valve. ; in: This represents the flow rate in the pilot valve passage.

8. The flow control method based on a conical valve core pilot valve according to claim 7, characterized in that, In step A1, the inflow and outflow volumes of the pilot upper cavity are: ； ； in: The inflow and outflow volume within the minimum operating time period; For the correction factor of influent and effluent; This is the minimum operating time cycle of the solenoid valve; The inlet and outlet flow rates of the pilot upper cavity; This refers to the inner diameter of the pipe. The pressure before the main pressure reducing valve; Standard atmospheric pressure; For fluid density; The length of the pipe; This is the frictional resistance coefficient along the friction path.

9. The flow control method based on a conical valve core pilot valve according to claim 7, characterized in that, In step A1, the inflow and outflow volumes of water in the pilot upper cavity are: ； ； in: The inlet and outlet water volumes after the nth pressure stabilization; The volume of water entering and exiting after the (n-1)th pressure stabilization is denoted as . The inlet and outlet water flow rates of the pilot upper cavity after the nth pressure stabilization; This represents the minimum operating time period of the solenoid valve after the nth voltage stabilization. The pressure before the main pressure reducing valve; Standard atmospheric pressure; The Hooke's constant of the spring under pilot conditions; S u This is the equivalent area of ​​the upper diaphragm; This refers to the inner diameter of the pipe. For fluid density; The length of the pipe; This is the frictional resistance coefficient along the friction path.

10. A flow control system based on a conical valve core pilot valve, implemented based on the flow control method based on a conical valve core pilot valve as described in any one of claims 1-9, characterized in that, It includes a fast voltage regulation module, a stable voltage regulation module, an intelligent voltage regulation module, and a flow prediction module; The rapid voltage adjustment module is used to rapidly adjust the voltage according to the operating conditions; The voltage stabilization module is used to stabilize and regulate voltage according to operating conditions. The intelligent voltage regulation module is used to intelligently regulate the voltage according to the operating conditions. The flow prediction module is used to estimate the total flow of valves that offer rapid pressure regulation, stable pressure regulation, or intelligent pressure regulation.

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