Water medium loading pressure stabilizing system

Abstract

The invention discloses a water medium loading pressure stabilizing system, and relates to the technical field of concrete water load simulation. The system comprises a loading unit used for applying water pressure to a concrete test piece, a pressure stabilizing unit connected with the loading unit and used for providing stable power input for the loading unit, a water supplementing unit used for supplementing water to the system and a control system. The pressure stabilizing unit comprises a hydraulic cylinder and a proportional control valve, and the control system dynamically adjusts the oil pressure of the hydraulic cylinder through the proportional control valve according to a water pressure signal collected by the pressure sensor in real time, so that the output water pressure of the loading unit is accurately controlled. Through closed-loop feedback control, the problems that in the prior art, the pressure stabilizing precision is insufficient, and time-varying load and seepage compensation are difficult to simulate are solved, high-precision and dynamic pressure stabilizing loading of the concrete structural surface with natural defects in a real water medium environment is achieved, and a reliable test platform is provided for research of a hydraulic fracturing mechanism and dam safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete structure service environment simulation, and particularly relates to a water medium loading and pressure stabilizing system for simulating the real water load environment of a water conservancy concrete structure surface of a dam under high water head action. BACKGROUND

[0002] In the simulation research of concrete structure service environment, the environmental simulation technology has developed from single climate parameters such as temperature and humidity to comprehensive simulation of multi-field coupling such as climate-mechanical environment. Although existing devices such as artificial marine environment test boxes and plateau high-cold simulation boxes can effectively simulate light, heat and other climate conditions, the mechanical environment simulation is still mainly based on single mechanical action such as static load, vibration or impact. For the specific water load environment of a dam and other water conservancy concrete structures, especially the real simulation of the hydraulic splitting effect under high water head action, the existing technology has not fully solved the matching problem of the load medium, the structure surface form and the actual service conditions.

[0003] At present, water load simulation devices are mainly divided into two categories: one is mechanical loading, which cannot restore the physical nature of water medium penetration; the other is direct water pressure loading, but it is mostly limited to local water injection or overall immersion and pressurization of small-sized test pieces. The former is difficult to reflect the real response of mass concrete due to the size effect of the test piece, and the latter simplifies the water pressure transmission mechanism by ignoring the seepage path of the structure surface. Although some scholars have improved the crack water pressure applying device, the water tightness design is still based on artificial precast cracks, which is difficult to simulate the gradual damage process of the real dam structure surface in the water environment.

[0004] In addition, the existing water load devices generally have the problems of insufficient pressure stabilizing precision and limited time-varying load simulation capability. The water load borne by the real concrete dam has dynamic nature and spatial distribution complexity due to the influence of water level fluctuation, seepage gradient and the like, while the current devices mostly rely on constant pressure water source or simple valve control, lack of high-precision pressure stabilizing and real-time feedback mechanism, resulting in deviation between the test data and the actual working conditions. The existing technology cannot meet the core requirements of "real structure surface, real water medium and real load characteristics" at the same time, and there is still a big difference between the water load action of the concrete high dam under the existing test conditions and the real service conditions.

[0005] Therefore, there is an urgent need for a water load pressure stabilizing device, that is, a water load device capable of simulating the long-term bearing of high water head pressure of mass concrete structure surface in the water environment, having dynamic pressure stabilizing function and taking into account the seepage-mechanical coupling effect, to provide a reliable test platform for the study of hydraulic splitting mechanism and dam safety. SUMMARY

[0006] The application aims to provide a water medium loading pressure stabilizing system to solve the problems of insufficient pressure stabilizing precision, difficulty in simulating dynamic time-varying load and real seepage-mechanical coupling effect in the prior art.

[0007] To achieve the above-mentioned object, the application provides a water medium loading pressure stabilizing system, comprising: a loading unit for containing water medium and applying water pressure to a concrete test piece arranged therein; a pressure stabilizing unit connected with the loading unit, the pressure stabilizing unit being used for providing controllable power input for the loading unit to maintain stable water pressure output; a water supplementing unit for supplementing water medium to the loading unit; a control system, the loading unit, the pressure stabilizing unit and the water supplementing unit being signal connected with the control system, the control system being used for receiving pressure signals and controlling the actions of the pressure stabilizing unit and the water supplementing unit to realize accurate loading and stable maintenance of water pressure.

[0008] Preferably, the pressure stabilizing unit comprises a hydraulic cylinder and a proportional control valve, the proportional control valve being used for adjusting the flow and direction of hydraulic oil flowing to the hydraulic cylinder according to the instruction of the control system; the loading unit comprises a loading pressure stabilizing water cylinder, the loading pressure stabilizing water cylinder being communicated with a loading water tank, the concrete test piece being arranged in the loading water tank, the piston of the loading pressure stabilizing water cylinder being linked with the piston rod of the hydraulic cylinder; a pressure sensor is arranged at the pressure water inlet of the loading water tank, and the pressure sensor is signal connected with the control system.

[0009] Preferably, the proportional control valve is a proportional reversing valve, the proportional reversing valve receiving the current signal output from the proportional amplifier of the control system through a proportional electromagnet to proportionally control the displacement of the valve core.

[0010] Preferably, a water pressing one-way valve and a water absorbing one-way valve are arranged between the loading unit and the water supplementing unit; when the piston of the loading pressure stabilizing water cylinder advances, the water medium flows to the loading area of the concrete test piece through the water pressing one-way valve; when the piston of the loading pressure stabilizing water cylinder retreats, the water medium is absorbed from the water supplementing unit through the water absorbing one-way valve.

[0011] Preferably, the water supplementing unit comprises a water storage tank, a water level meter and a water supplementing electromagnetic valve; the water level meter is used for monitoring the water level in the water storage tank, and the control system controls the opening and closing of the water supplementing electromagnetic valve according to the water level signal monitored by the water level meter to automatically supplement water from an external water source to the water storage tank.

[0012] Preferably, a gas releasing valve is arranged on the loading water tank, and the gas releasing valve is used for discharging the gas inside the loading water tank.

[0013] Preferably, the loading water tank is a pressure vessel made of stainless steel, and the maximum design pressure of the loading water tank is not less than 5 MPa.

[0014] Preferably, the pressure stabilizing unit further comprises a hydraulic station for supplying oil to the hydraulic cylinder, the hydraulic station comprising an oil tank, a servo motor and an oil pump; the servo motor is signal-connected with the control system, and the servo motor is connected with the oil pump and used to drive the oil pump to work; an outlet pipeline of the oil pump is communicated with the proportional control valve, and the outlet pipeline of the oil pump is also communicated with an overflow valve.

[0015] Preferably, the hydraulic station further comprises a cooling fan, and the cooling fan is used to cool the hydraulic oil flowing through the overflow valve.

[0016] Preferably, the water medium loading pressure stabilizing method based on the water medium loading pressure stabilizing system comprises the following steps: placing a concrete test piece in a loading area of the loading unit; setting a target water pressure value and a pressure maintaining parameter by the control system; starting the system, and driving the loading unit to apply water pressure to the test piece by the pressure stabilizing unit; real-time collecting an actual water pressure of the loading area and feeding back to the control system; comparing the actual water pressure with the target water pressure by the control system, dynamically compensating pressure deviation by adjusting the proportional control valve of the pressure stabilizing unit, and realizing pressure stabilization; when the water medium is reduced due to seepage, water absorption or system micro-leakage of the test piece during the loading process, the water supplement unit automatically supplements water to the system under the control of the control system, so as to maintain water balance and pressure stability of the system.

[0017] Compared with the prior art, the present application has the following advantages and technical effects: The water medium loading pressure stabilizing system provided by the present application realizes simulation of a real water medium environment of a concrete structure surface with natural defects through the cooperative work of the loading unit, the pressure stabilizing unit based on hydraulic proportional control, the automatic water supplement unit and the closed-loop control system. The system can compensate pressure and supplement water in real time and accurately according to pressure loss caused by seepage, water absorption and the like of the concrete test piece during pressure bearing, and solves the problems of low pressure stabilization precision and inability to simulate dynamic seepage coupling of the traditional device. The system has high pressure control precision (up to ±1%), can be operated stably for a long time, provides a highly realistic and reliable test means for dam hydraulic splitting mechanism research and damage evolution process analysis of concrete under high water head, and has important engineering application value. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 The figure is a schematic diagram of the principle of the water medium loading and pressure stabilizing system of the present application.

[0020] In the figure: 1, oil tank; 2, servo motor; 3, oil pump; 4, oil pressure gauge; 5, overflow valve; 6, proportional reversing valve; 7, hydraulic cylinder; 8, loading and pressure stabilizing water cylinder; 9, water pressure check valve; 10, water suction check valve; 11, water storage tank; 12, water level gauge; 13, control system; 14, water replenishing electromagnetic valve; 15, water inlet pipe of tap water; 16, pressure sensor; 17, air release valve; 18, cooling fan; 19, loading water tank. DETAILED DESCRIPTION

[0021] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The described embodiments are only some of the embodiments of the present application, not all. All other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] As shown in Figure 1 The present application provides a water medium loading and pressure stabilizing system, comprising: A loading unit for containing water medium and applying water pressure to a concrete test piece placed therein; A pressure stabilizing unit connected with the loading unit, the pressure stabilizing unit being configured to provide controllable power input to the loading unit to maintain stable water pressure output; A water replenishing unit configured to replenish water medium to the loading unit; A control system 13, the loading unit, the pressure stabilizing unit and the water replenishing unit are all signal connected with the control system 13; the control system 13 is configured to receive pressure signals and control the actions of the pressure stabilizing unit and the water replenishing unit to realize accurate loading and stable maintenance of water pressure.

[0023] This invention, through the configuration of a loading unit, a pressure stabilizing unit, a water supply unit, and a control system 13, can construct a complete, closed-loop system for loading and maintaining stability of water medium pressure. Specifically, the loading unit directly simulates the water load environment, the pressure stabilizing unit provides a precise and controllable power source, the water supply unit ensures the supply of the medium, and the control system 13 acts as the brain coordinating all actions. Together, they solve the core problem mentioned in the background art—the difficulty of simultaneously satisfying "real structural surface, real water medium, and real load characteristics"—and achieve high-precision loading simulation of concrete specimens in a real water environment.

[0024] The scheme is further optimized. The pressure stabilizing unit includes a hydraulic cylinder 7 and a proportional control valve. The proportional control valve adjusts the flow rate and direction of the hydraulic oil flowing to the hydraulic cylinder 7 according to the instructions of the control system 13. The loading unit includes a loading and pressure stabilizing water cylinder 8, which is connected to a loading water tank 19. The concrete specimen is placed in the loading water tank 19. The piston of the loading and pressure stabilizing water cylinder 8 is linked with the piston rod of the hydraulic cylinder 7. A pressure sensor 16 is installed at the pressure water inlet of the loading water tank 19. The pressure sensor 16 is connected to the control system 13.

[0025] By using hydraulic cylinder 7 and a proportional control valve, the electrical control signal can be precisely converted into mechanical action, thereby driving the loading unit. Hydraulic drive provides high power and fast response, making it suitable for high water pressure loading. The proportional control valve allows for continuous, smooth, stepless adjustment of the hydraulic oil flow and direction, overcoming the shortcomings of traditional on / off valves, such as low control accuracy and large impact. This provides a crucial actuator for achieving high-precision, dynamically stable water pressure control.

[0026] The scheme is further optimized so that the proportional control valve is a proportional directional valve 6. The proportional directional valve 6 receives the current signal output from the proportional amplifier of the control system 13 through a proportional electromagnet to proportionally control the valve core displacement.

[0027] By specifying the proportional control valve as a proportional directional valve 6, precise proportional control of the liquid flow direction and flow rate via electrical signals can be achieved. The minute current changes output by the control system 13 are amplified by a proportional amplifier to drive a proportional electromagnet. The thrust generated by the electromagnet is proportional to the current, thereby causing the valve core to displace proportionally to the current. This direct electromechanical conversion method offers fast response and good control linearity, forming the basis for closed-loop pressure control.

[0028] To further optimize the scheme, a pressure check valve 9 and a suction check valve 10 are installed between the loading unit and the water replenishment unit. When the piston of the loading pressure stabilizing cylinder 8 is pushed forward, the water medium flows to the loading area of ​​the concrete specimen through the pressure check valve 9. When the piston of the loading pressure stabilizing cylinder 8 is retracted, the water medium is drawn from the water replenishment unit through the suction check valve 10.

[0029] By setting up the pressure check valve 9 and the suction check valve 10, the water medium can be ensured to flow in one direction in the system, realizing the automatic and orderly switching between the loading and suction processes. The pressure check valve 9 prevents high-pressure water from flowing back during the piston's return stroke, while the suction check valve 10 ensures that the piston can only draw water from the water storage tank 11 during the return stroke, avoiding chaotic operation and energy loss. This allows the loading and pressure-stabilizing water cylinder 8 to work cyclically like a "water pump," continuously providing and regulating water pressure.

[0030] The water replenishment unit is further optimized to include a water storage tank 11, a water level gauge 12, and a water replenishment solenoid valve 14. The water level gauge 12 is used to monitor the water level in the water storage tank 11. The control system 13 controls the opening and closing of the water replenishment solenoid valve 14 according to the water level signal monitored by the water level gauge 12, so as to connect an external water source to automatically replenish water to the water storage tank 11.

[0031] The water replenishment unit automatically maintains the overall balance of the system's working medium. In cases of long-term testing or sudden specimen cracking requiring a large influx of water, the water storage tank 11 provides buffering and reserves. The water level gauge 12 monitors the water level in real time. When the water level falls below the set lower limit, the control system 13 automatically opens the water replenishment solenoid valve 14 to introduce external water (such as tap water) until the water level returns to the set value, at which point it closes. This ensures a sufficient water supply to the system under any operating conditions, a crucial guarantee for maintaining long-term pressure stability.

[0032] To further optimize the design, a vent valve 17 is installed on the loading water tank 19. The vent valve 17 is used to remove the gas inside the loading water tank 19.

[0033] The vent valve 17 serves to release gas from the loading unit and its pipelines after initial water injection or maintenance. If gas is present in the system, it will be compressed during pressurization, leading to slow pressure response, decreased control accuracy, and even pressure pulsation and "air hammer" phenomena, severely affecting the authenticity of the test and equipment safety. The vent valve 17 ensures that the loading medium is pure water, enabling rapid and accurate pressure transmission, which meets the application requirements of Pascal's principle.

[0034] The design was further optimized so that the loading tank 19 is a pressure vessel made of stainless steel, and the maximum design pressure of the loading tank 19 is not less than 5MPa.

[0035] By designing the loading tank 19 as a stainless steel tank with a pressure-bearing capacity of no less than 5MPa, it can simultaneously meet the requirements of high strength, corrosion resistance, and long-term service. Stainless steel (such as 304 stainless steel) has high strength and can withstand minimal deformation under 5MPa high pressure (e.g., strain not exceeding 1e). -6It ensures the geometric stability of the loading space; at the same time, it has strong resistance to water corrosion, ensuring the reliability and life of the equipment in humid and high-pressure environments, meeting the engineering requirements of simulating a 300-meter-high dam head (about 3MPa) with sufficient safety margin.

[0036] In a further optimized design, the pressure stabilizing unit also includes a hydraulic station that supplies oil to the hydraulic cylinder 7. The hydraulic station includes an oil tank 1, a servo motor 2, and an oil pump 3. The servo motor 2 is connected to the control system 13 via a signal, and the servo motor 2 is connected to the oil pump 3 and used to drive the oil pump 3 to work. The outlet pipe of the oil pump 3 is connected to a proportional control valve, and the outlet pipe of the oil pump 3 is also connected to an overflow valve 5.

[0037] The hydraulic station provides a stable and clean hydraulic oil source for the entire pressure stabilization unit, ensuring system safety. Servo motor 2 drives oil pump 3, providing power to the system. Relief valve 5 acts as a safety valve, opening to overflow when the system pressure exceeds a set safety value, preventing damage to hydraulic components due to overpressure; it is an essential safety device for the hydraulic system.

[0038] In a further optimized design, the hydraulic station also includes a cooling fan 18, which is used to cool the hydraulic oil flowing through the relief valve 5.

[0039] The cooling fan 18 serves to manage the thermal performance of the hydraulic system and prevent the hydraulic oil from overheating. During continuous long-term operation, especially under high load and pressure stabilization, the hydraulic oil temperature rises due to throttling and friction. Excessive oil temperature leads to decreased oil viscosity, poor lubrication performance, accelerated aging of seals, and even oil oxidation and deterioration. The cooling fan 18 effectively controls the oil temperature within a reasonable range by providing forced air cooling to the oil tank or oil circuit radiator, ensuring the long-term stable operation of the hydraulic system.

[0040] The overall implementation process of the water-medium loading and stabilizing system provided by this invention is as follows: During implementation, the concrete specimen to be tested (which can simulate the structural surface of a dam) is first placed in a custom-designed high-head loading tank 19 (belonging to the loading area), and then closed and sealed. Through the touchscreen interface of the control system 13, parameters such as the target water pressure value (e.g., within the range of 0.5MPa to 5MPa), pressure holding time, and pressure control accuracy (e.g., ±5% or higher) are set. After checking that the water level in the storage tank 11 is sufficient, the vent valve 17 is opened, the system is started, and the loading pressure-stabilizing cylinder 8 is allowed to reciprocate several times to expel residual gas from the pipeline. Then, the vent valve 17 is closed.

[0041] After the system starts, servo motor 2 drives oil pump 3 to draw oil from oil tank 1 and generate pressurized oil. The pressurized oil enters hydraulic cylinder 7 through relief valve 5 (sets the system's maximum safe pressure) and proportional directional valve 6. According to the initial settings, control system 13 outputs a command signal to the proportional solenoid of proportional directional valve 6, driving the valve core to move, controlling hydraulic cylinder 7 to extend, and thus pushing the piston of loading and stabilizing water cylinder 8 forward. When the piston moves forward, suction check valve 10 closes and pressure check valve 9 opens, forcing water medium into high-head loading water tank 19 to apply pressure to the concrete specimen.

[0042] Pressure sensor 16 monitors the water pressure in loading tank 19 in real time and feeds the signal back to control system 13. The core controller (such as a PLC) of control system 13 compares the real-time pressure with the target pressure and calculates the pressure deviation. Based on the magnitude and direction of the deviation, the system adjusts the current signal output to proportional directional valve 6 in real time using a built-in control algorithm (such as a PID algorithm). Changes in the current signal precisely alter the opening size and direction of proportional directional valve 6, thereby regulating the flow rate and direction of the oil entering hydraulic cylinder 7, dynamically adjusting the thrust and movement of hydraulic cylinder 7, and ultimately achieving precise closed-loop control of the output water pressure of loading and stabilizing water cylinder 8. For example, when the actual pressure is lower than the target value, the system controls hydraulic cylinder 7 to advance further, increasing the output and achieving pressure stabilization.

[0043] During the loading and pressure holding process, because the concrete specimen is a porous medium, water will seep through its internal microcracks and pores, or be absorbed by the concrete material, resulting in a slight decrease in the water volume in the loading water tank 19 and a downward pressure trend. At this time, the pressure sensor 16 detects the pressure drop, and the control system 13 immediately starts the pressure stabilization program. By fine-tuning the proportional directional valve 6, it drives the hydraulic cylinder 7 and the loading and pressure stabilizing water cylinder 8 to make subtle compensating thrusting movements, quickly restoring the pressure to the set value. This process is automatic, continuous, and rapid, with a response time of up to seconds, thus achieving dynamic pressure stabilization under specimen seepage conditions.

[0044] Meanwhile, during the reciprocating operation of the pressure-stabilizing water cylinder 8, water is drawn from the water storage tank 11 through the suction check valve 10 when the piston retracts, replenishing the volume of its working chamber. The water level in the water storage tank 11 is monitored by the water level gauge 12. As the test progresses, especially when the concrete specimen cracks and a large amount of water needs to be replenished instantly, the water level in the water storage tank 11 will drop. When the water level falls below the preset minimum water level, the water level gauge 12 sends a signal to the control system 13, which then opens the water replenishment solenoid valve 14. External water (such as tap water) flows into the water storage tank 11 through the tap water inlet pipe 15 until the water level returns to the preset height, at which point the solenoid valve closes. This ensures a continuous and sufficient water supply for the entire system, supporting long-term uninterrupted testing.

[0045] The heat generated by the hydraulic system during prolonged operation is forcibly dissipated by the cooling fan 18 to the oil circuit or oil tank, maintaining a stable oil temperature. The vent valve 17 on top of the loading water tank 19 can be manually opened when necessary to release any accidentally accumulated gas and ensure the purity of the pressure transmission medium.

[0046] The water-medium loading and stabilizing system provided by this invention is theoretically divided into two parts: pressurization and stabilization.

[0047] 1. Pressurization principle The water pressure of the pressure-stabilizing water cylinder 8 is controlled by the oil pressure of the hydraulic cylinder 7. The working principle of the hydraulic cylinder 7 is Pascal's law, which states that in a static fluid in a closed container, a pressure change at a certain point will be transmitted equally to all parts of the fluid.

[0048] A force F1 is applied to oil pump 3. According to the pressure formula: According to Pascal's law, pressure P1 is transmitted equally to the entire closed system through incompressible hydraulic oil, and the pressure in the water pump is also P1.

[0049] The force F2 output by the water pump is: The magnification factor is obtained as the ratio of the water pump piston area to the oil pump piston area. In this device, it is taken as 2.47. That is, when the water pressure is 2MPa, the oil pressure should be set to 2 x 2.47 = 4.94MPa.

[0050] 2. Voltage stabilization principle The concrete dam structure is directly placed in the loading water tank 19. Under load, the structure undergoes a certain opening displacement, and the water medium inside the tank seeps into the dam body through the structure, forming pressurized seepage within the micro-cracks of the dam body. Therefore, during pressure-stabilized loading, the seepage problem within the concrete cracks must be considered. The mechanism of water transport in concrete is studied, the water transport process under pressure is analyzed, and the pressure head loss during loading is predicted. Based on this, the pressure compensation system is adjusted to precisely control the pressurization.

[0051] Consider a closed system consisting of a water tank, a concrete specimen, and external piping. Its spatial boundaries are leak-proof and do not undergo structural deformation (i.e., rigid boundaries). When water in the system is subjected to external pressure, it seeps, adsorbs, or undergoes volume compression along the concrete pore network. Then, at any time t, the total mass of water in the system must satisfy conservation, i.e.: Initial water mass + input water mass = absorbed mass + seepage mass + compressed water mass The corresponding mathematical expression is: in, The initial water mass in the pressurized container at the start of the test is represented by the following formula: in, This is the density of water, expressed in kg / m³. 3 (Commonly taken as 998kg / m) 3 (at 20℃); V0 is the volume of water in the tank, in cubic meters. 3 .

[0052] The mass of water injected into the system from the external pressurization system before time t is typically obtained by measuring the flow rate using a cumulative flow meter, converting it to volume, and then multiplying it by the water density. The calculation formula is as follows: in, The instantaneous volumetric velocity recorded by the flow meter, in meters per second (m). 3 / s; This represents the mass of water absorbed in concrete (i.e., water that enters its pore network without forming channels). As a porous material, concrete's pore network allows liquid water to enter through mechanisms such as capillary adsorption, surface tension, and pore pressure gradients under water pressure or capillary drive. The calculation formula is as follows: Where A is the area of ​​the concrete specimen in contact with water, in m². 2 S represents the water absorption rate of the material, which is affected by the capillary distribution of the concrete, the interfacial contact state, and the water saturation. The unit is m·s. (-1 / 2) t represents the water absorption time, measured in seconds (s).

[0053] This represents the mass of water seeping through cracks in concrete. Seepage refers to the flow of fluid in a porous medium. A porous medium is a substance composed of granular or fragmented materials and containing many pores or cracks. Concrete is a typical porous medium. Applying this law to concrete—assuming the channels formed by the pores in the concrete are in a low-velocity, stable state—we obtain the following calculation formula: Where k is the permeability, in meters. 2 μ is the dynamic viscosity of water, in Pa·s; L is the penetration thickness, in m; P(t) is the pressure at the pressurized end, in Pa.

[0054] The term representing the additional mass change caused by the volume compression of water in a pressurized container under high pressure is calculated using the following formula: in, The initial water density (the density of water when the water pressure is 0), in kg / m³. 3 ; The volume compressibility of water is approximately 4.5 × 10⁻⁶ at 20°C. -10 Pa -1 ; The volume of water involved in the compression, in meters (m). 3 .

[0055] The sum of the above five masses constitutes a closed mass balance system. The left side represents the real-time measurement and calculation, while the right side represents the theoretical calculation. By comparing the masses on the left and right sides, if the left side is greater than the right side, the water pressure is too high; if the left side is less than the right side, the water pressure is too low; and if the left side is equal to the right side, a stable pressure is achieved.

[0056] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A water-medium loaded voltage stabilization system, characterized in that, include: A loading unit is used to contain a water medium and apply water pressure to a concrete specimen placed therein. A pressure stabilizing unit is connected to the loading unit, and the pressure stabilizing unit is used to provide a controllable power input to the loading unit to maintain a stable water pressure output; A water replenishment unit is used to replenish the loading unit with water medium. The control system (13) is connected to the loading unit, the pressure stabilizing unit and the water replenishment unit by signal. The control system (13) is used to receive pressure signals and control the actions of the pressure stabilizing unit and the water replenishment unit to achieve precise loading and stable maintenance of water pressure.

2. The water-medium loading and stabilizing system according to claim 1, characterized in that, The pressure stabilizing unit includes a hydraulic cylinder (7) and a proportional control valve. The proportional control valve adjusts the flow rate and direction of the hydraulic oil flowing to the hydraulic cylinder (7) according to the instructions of the control system (13). The loading unit includes a loading pressure stabilizing water cylinder (8). The loading pressure stabilizing water cylinder (8) is connected to a loading water tank (19). The concrete specimen is placed in the loading water tank (19). The piston of the loading pressure stabilizing water cylinder (8) is linked with the piston rod of the hydraulic cylinder (7). A pressure sensor (16) is provided at the pressure water inlet of the loading water tank (19). The pressure sensor (16) is connected to the control system (13) via a signal.

3. The water-medium loading and stabilizing system according to claim 2, characterized in that, The proportional control valve is a proportional directional valve (6). The proportional directional valve (6) receives the current signal output from the proportional amplifier of the control system (13) through a proportional electromagnet to proportionally control the valve core displacement.

4. The water-medium loading and stabilizing system according to claim 2, characterized in that, A pressure check valve (9) and a suction check valve (10) are provided between the loading unit and the water replenishment unit. When the piston of the loading pressure stabilizing cylinder (8) is pushed forward, the water medium flows to the loading area of ​​the concrete specimen through the pressure check valve (9). When the piston of the loading pressure stabilizing cylinder (8) is retracted, the water medium is drawn from the water replenishment unit through the suction check valve (10).

5. The water-medium loading and stabilizing system according to claim 1, characterized in that, The water replenishment unit includes a water storage tank (11), a water level gauge (12), and a water replenishment solenoid valve (14). The water level gauge (12) is used to monitor the water level in the water storage tank (11). The control system (13) controls the opening and closing of the water replenishment solenoid valve (14) according to the water level signal monitored by the water level gauge (12) so as to connect an external water source to automatically replenish water to the water storage tank (11).

6. The water-medium loading and stabilizing system according to claim 2, characterized in that, The loading water tank (19) is equipped with a vent valve (17), which is used to release the gas inside the loading water tank (19).

7. The water-medium loading and stabilizing system according to claim 2, characterized in that, The loading water tank (19) is a pressure vessel made of stainless steel, and the maximum design pressure of the loading water tank (19) is not less than 5MPa.

8. The water-medium loading and stabilizing system according to claim 2, characterized in that, The pressure stabilizing unit also includes a hydraulic station for supplying oil to the hydraulic cylinder (7). The hydraulic station includes an oil tank (1), a servo motor (2), and an oil pump (3). The servo motor (2) is connected to the control system (13) via a signal, and the servo motor (2) is connected to the oil pump (3) and used to drive the oil pump (3) to work. The outlet pipe of the oil pump (3) is connected to the proportional control valve, and the outlet pipe of the oil pump (3) is also connected to an overflow valve (5).

9. The water-medium loading and stabilizing system according to claim 8, characterized in that, The hydraulic station also includes a cooling fan (18) for cooling the hydraulic oil flowing through the relief valve (5).

10. The water-medium loading and stabilizing system according to any one of claims 1-9, characterized in that, The water-medium loading voltage stabilization method based on the aforementioned water-medium loading voltage stabilization system includes the following steps: Place the concrete specimen in the loading area of ​​the loading unit; The target water pressure value and pressure holding parameters are set through the control system (13); The system is started, and the pressure stabilizing unit drives the loading unit to apply water pressure to the specimen; Real-time acquisition of actual water pressure in the loading area and feedback to the control system (13); The control system (13) compares the actual water pressure with the target water pressure and dynamically compensates for the pressure deviation by adjusting the proportional control valve of the pressure stabilizing unit to achieve pressure stabilization. When the water medium is reduced due to seepage, water absorption or micro-leakage of the test specimen during loading, the water replenishment unit automatically replenishes water to the system under the control of the control system (13) to maintain the system water balance and pressure stability.

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