A mixed ball valve control system based on oil and water medium

Abstract

The application discloses a kind of mixed ball valve control systems based on oil, water medium, it is related to water inlet ball valve hydraulic control technical field, comprising: water medium operating unit is configured as using water medium control water inlet ball valve opening and closing and the commissioning seal is put off and put on;Oil medium control unit is configured as using oil medium to realize electro-hydraulic conversion and hydraulic protection logic function;Medium coupling unit, using control cavity and constant pressure cavity complete isolation of liquid control reversing valve, is configured to realize the pressure signal transmission and logic linkage of oil, water medium.The application uses water medium for the direct operation circuit of water inlet ball valve, uses oil medium for control circuit, and realizes the function coupling and logic transmission of two kinds of media by isolated liquid control reversing valve, realizes the control of water inlet ball valve, both solves the technical problems that existing full-oil pressure control system is higher in cost, pollutes environment when leaking, unsafe and inconvenient to maintain, and solves the technical problem that full-water pressure control system is poor in reliability.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology for inlet ball valves, specifically to a hybrid ball valve control system based on oil and water media. Background Technology

[0002] The high-head pumps / turbines are connected to the upstream reservoir via pressure steel pipes. Water from the upstream reservoir is transported to the downstream units through these pipes. Each unit is equipped with an inlet ball valve at the spiral casing inlet to cut off the water flow when necessary. In an emergency, the inlet ball valve can be closed under full flow conditions to protect the units and power plant equipment.

[0003] The inlet ball valve is opened and closed by operating a relay. The controlled objects of the inlet ball valve usually include the valve, maintenance seal, and working seal. There are strict sequence requirements between the valve, working seal, and maintenance seal. In practical applications, it is usually necessary to implement sequential logic in the hydraulic system to prevent misoperation from causing damage to key components such as the working seal ring and maintenance seal ring, resulting in downtime for maintenance.

[0004] Currently, inlet ball valves typically employ a fully hydraulic control system for operation relays. For example, document CN108194688A discloses a hydraulic control system for an inlet ball valve, which includes a sealing and locking control oil circuit and a ball valve control oil circuit. It features full hydraulic and mechanical interlocking protection and an automatic working seal activation function after valve closure. The sealing and locking control oil circuit includes: a control oil source via a branch oil circuit of the maintenance seal interlocking valve to the interlocking activation hydraulic control valve, and then connected to the hydraulic locking device via a hydraulic locking solenoid valve; the control oil source via the working seal operating valve and the maintenance seal operating valve, respectively connected to the working seal and the maintenance seal; and a shuttle valve connected to the working seal pilot valve, the interlocking activation hydraulic control valve, and the working seal operating valve. The ball valve control oil circuit includes: a branch oil circuit leading from the oil line of the relay opening chamber to the pressure replenishment oil circuit via the replenishment and pressure holding combination valve to the control oil port on the opening valve side of the main operating valve; the control oil source to the opening valve solenoid valve is sequentially equipped with a maintenance sealing lock valve, a working sealing lock valve, and a hydraulic lock pin lock valve, forming a lockout oil circuit; the rest are actuation oil circuits. This hydraulic control system has the function of preventing damage to the inlet ball valve, but after careful analysis, it was found that the following technical problems still exist in operating the relay using a fully hydraulic control system: 1. The system is complex and has high investment costs. Large-scale generator sets have large-capacity ball valve relays; the fuel consumption for a full stroke from fully open to fully closed is over 1m³. 3 Based on relevant standards and considering the common requirement in current engineering projects that pressure oil tanks store at least four times the volume of the relay when operating at the lower limit of normal working oil pressure, and taking into account that the oil-to-air ratio of the pressure oil tank at rated oil pressure is between 1:2 and 1:3, and that the lower limit of normal working oil pressure is lower than the rated operating oil pressure, the volume of pressure oil tanks in general engineering projects is at least 18 to 20 m³.3 In addition, a complete hydraulic system requires a matching return oil tank, oil pump, and filter, as well as a medium-pressure air replenishment system and automatic air replenishment device to maintain a constant total gas volume in the pressure tank. This results in a significant increase in investment in facilities and equipment, such as the medium-pressure air replenishment station building, air compressor, and compressed air storage tank. This not only increases equipment costs but also occupies considerable valuable factory space.

[0005] 2. There is a potential leakage risk in the working sealing ring and the maintenance sealing ring. Oil in their engagement / disengagement chambers may enter the working flow channel of the ball valve through the leakage point, and then enter the reservoir, causing environmental pollution. Water in the flow channel may enter the engagement / disengagement chamber of the working / maintenance seal through the leakage point, and then enter the hydraulic system, causing hydraulic medium pollution, leading to system medium failure and significantly reducing the reliability of the hydraulic system.

[0006] 3. The equipment maintenance workload is large, and there are risks of leakage and pollution. The added hydraulic device and medium-pressure air supply system require daily operation and maintenance and regular inspection. Moreover, the hydraulic oil has extremely high cleanliness requirements. During maintenance, the hydraulic oil in the equipment and pipeline system must be drained. Oil leakage will not only pollute the plant and other hydraulic structures, but also pollute the environment, and the treatment cost is extremely high.

[0007] 4. Significant operational safety risks exist. Large-capacity pressure oil tanks and compressed air storage tanks are special equipment that operate under pressure for extended periods. In particular, the air supply pipeline runs through the entire main plant building, posing a risk of physical explosion due to fatigue, corrosion, or quality defects, which would seriously threaten the safety of nearby equipment and personnel.

[0008] In recent years, to simplify systems and reduce costs, water-based hydraulic systems have emerged that directly utilize water pressure in pressurized steel pipes as a power source. However, water has characteristics such as low viscosity, poor lubricity, easy corrosion, and cavitation, leading to low reliability, short lifespan, and low standardization of water-based hydraulic components. In particular, the technological maturity of electro-hydraulic conversion and complex logic control is far lower than that of hydraulic systems. Therefore, existing technologies lack a hydraulic control scheme that can both utilize water to drive the main operating mechanism of a ball valve and simultaneously ensure high-reliability logic control and system protection. Summary of the Invention

[0009] To address the shortcomings and defects of the existing technologies, this invention proposes a hybrid ball valve control system based on oil and water media. By using water media in the direct operating circuit of the inlet ball valve and oil media in the control circuit, and by using an isolated hydraulic directional valve to achieve functional coupling and logical transmission between the two media, the control of the inlet ball valve is realized. This solves the technical problems of existing all-oil pressure control systems, such as the need to establish an oil station, high cost, environmental pollution, safety issues, and inconvenience in maintenance when leaking, as well as the technical problem of poor reliability of all-water pressure control systems.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A mixed ball valve control system based on oil and water media includes: The water medium operating unit is configured to control the opening and closing of the inlet ball valve and the activation and deactivation of the maintenance seal using water medium. The oil medium control unit is configured to use oil medium to realize electro-hydraulic conversion and hydraulic protection logic functions; The medium coupling unit, which employs a hydraulically controlled directional valve that completely isolates the control chamber from the constant pressure chamber, is configured to realize the transmission of pressure signals and logical linkage between oil and water media.

[0011] The water medium operation unit includes: The relay is configured to control the opening and closing of the inlet ball valve; The water pressure cartridge valve assembly, controlled by the media coupling unit, is configured to connect to the opening chamber of the servo, the closing chamber of the servo, the pressure water source, and the drain outlet, respectively, and is used to control the connection of the opening / closing chamber of the servo to the pressure water source / drain. The maintenance seal control valve is configured to connect to both the maintenance seal engagement / disengagement chamber and the pressurized water source.

[0012] The media coupling unit includes a first hydraulically controlled directional valve, a second hydraulically controlled directional valve, a third hydraulically controlled directional valve, and a fourth hydraulically controlled directional valve. Both the first and second hydraulically controlled directional valves have an oil medium control chamber and a water medium constant pressure chamber, and both the third and fourth hydraulically controlled directional valves have an oil medium constant pressure chamber and a water medium control chamber. The water medium constant pressure chamber and water medium inlet of both the first and second hydraulically controlled directional valves are connected to a pressurized water source. The water medium outlet of the first hydraulically controlled directional valve is connected to a water-pressure cartridge valve assembly for controlling its operation. The water medium outlet of the second hydraulically controlled directional valve is connected to a working seal for controlling its operation. The first hydraulic directional valve is engaged or disengaged; the oil medium control chamber of the second hydraulic directional valve is connected to the pressure oil source via an engagement / disengagement solenoid valve; the oil medium constant pressure chambers of the third and fourth hydraulic directional valves are both connected to the pressure oil source; the water medium control chamber of the third hydraulic directional valve is connected to the engagement chamber of the working seal; the water medium control chamber of the fourth hydraulic directional valve is connected to the engagement chamber of the maintenance seal; port B of the third hydraulic directional valve is connected to port P of the fourth hydraulic directional valve; port B of the fourth hydraulic directional valve is connected to the pressure oil source; the oil medium control unit is connected between the oil medium control chamber of the first hydraulic directional valve and port P of the third hydraulic directional valve.

[0013] In the first and second hydraulically controlled directional valves, the cross-sectional area of ​​the oil medium control chamber is larger than the cross-sectional area of ​​the water medium constant pressure chamber; in the third and fourth hydraulically controlled directional valves, the cross-sectional area of ​​the oil medium constant pressure chamber is smaller than the cross-sectional area of ​​the water medium control chamber.

[0014] The oil medium control unit includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a fifth hydraulic control valve, and a sixth hydraulic control valve. The oil port P of the sixth hydraulic control valve is connected to the third hydraulic control directional valve. The oil port B of the sixth hydraulic control valve is connected to the oil port P of the fifth hydraulic control valve. The oil port B of the fifth hydraulic control valve is connected to the oil port P of the third solenoid valve. The oil port B of the third solenoid valve is connected to the oil ports B of the first solenoid valve and the second solenoid valve, respectively. The oil port P of the second solenoid valve is connected to the oil port A of the first solenoid valve. The oil port P of the first solenoid valve is connected to the oil medium control chamber of the first hydraulic control directional valve.

[0015] Both the fifth and sixth hydraulic control valves are two-position four-way hydraulic control directional valves. The hydraulic control chamber of the fifth hydraulic control valve is connected to the mechanical overspeed protection device, and the hydraulic control chamber of the sixth hydraulic control valve is connected to the tail brake fully open position stroke directional valve.

[0016] The water pressure cartridge valve assembly includes two or four cartridge valves. When it includes four cartridge valves, the four cartridge valves are arranged in parallel in pairs and are respectively connected to the opening chamber of the relay, the closing chamber of the relay, the pressure water source and the drain port.

[0017] The cartridge valve includes a valve body with a valve cover fixed at the upper end and two water inlets at the lower end. A valve seat is fixed inside one of the water inlets. A valve core that can move up and down is provided inside the valve body. The valve core cooperates with the valve seat to control the opening and closing of the water inlet. A piston is provided in the middle of the valve core, which divides the inner cavity of the valve body into upper and lower control chambers. The valve body has connection ports that communicate with the control chambers respectively. The area of ​​the two control chambers acting on the axial movement hydraulic pressure of the valve core is greater than the sum of the areas of the two water inlets acting on the valve core. The valve body also has two sets of elastic sealing components. One set of elastic sealing components is located between the piston and the valve body, and the other set of elastic sealing components is located both between the valve core and the valve body and between the lower control chamber and the water inlet.

[0018] The elastic sealing assembly includes an O-ring and a guide strip. The guide strip is made of PTFE mixed with copper powder. A stepped annular groove including a bottom groove and an outer groove is opened in the valve body. The width of the outer groove is greater than the width of the bottom groove. The O-ring is installed in the bottom groove and the guide strip is installed in the outer groove.

[0019] The upper part of the valve cover is provided with a self-resetting protection component for keeping the valve core in the closed position when the control chamber loses pressure. The self-resetting protection component includes a valve cover fixed to the upper part of the valve cover. The valve cover is provided with a reset spring, a guide spring post and a spring seat. The lower end of the guide spring post is fixed to the valve core and the upper end moves out of the valve cover. The spring seat and the reset spring are both movably sleeved on the guide spring post, and the reset spring is located between the spring seat and the valve core.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The hybrid ball valve control system provided by this invention employs water-medium control for the circuit directly controlling the opening and closing of the inlet ball valve, and oil-medium control for the circuit implementing hydraulic protection logic. A hydraulically controlled directional valve, with its control chamber and constant pressure chamber completely isolated, serves as the coupling unit between the oil and water media to achieve pressure signal transmission and logical linkage between the two media. Its core concept lies in using water as the main operating circuit, leveraging the advantages of water's cleanliness, environmental friendliness, ease of maintenance, system simplicity, and low cost. Simultaneously, the pilot control circuit uses oil as the medium, employing traditional and mature oil-medium hydraulic components, greatly improving system reliability. Furthermore, the oil-medium component can utilize hydraulic components conforming to GB / ISO / DIN standards, with mature technology, a complete supply chain, and a high degree of standardization. Compared to existing technologies, on the one hand, it can utilize existing pressurized water sources, eliminating the need for large hydraulic devices, saving equipment and space, reducing costs, and simplifying the structure. On the other hand, the main operating unit uses water as the medium, eliminating oil contamination during maintenance, making maintenance simpler. It also reduces the use of hydraulic oil and the risk of leakage, resulting in better environmental performance and higher safety. Furthermore, by using technologically mature hydraulic components for electro-hydraulic conversion and logic control, and employing water-based control only in the main operating unit, the reliability issues of hydraulic components in complex control systems can be avoided. In short, this invention combines the economic and environmental benefits of water-based media with the high reliability of oil-based media, making it suitable for high-head hydro-turbine generator sets and pump-turbine units. It offers advantages such as simplified structure, low cost, convenient maintenance, and safety redundancy.

[0021] 2. In the medium coupling unit, the cross-sectional area of ​​the control chamber is designed to be larger than that of the constant pressure chamber. When the pressure sources of the two chambers are properly matched with their cross-sectional areas, when the pressure in the control chamber is removed, the hydraulic valve is driven to switch to the return position under the action of the hydraulic pressure in the constant pressure chamber. When the control chamber is pressurized, due to the larger area of ​​the control chamber, the hydraulic force on one side of the control chamber is greater than that on the constant pressure chamber side, and the combined force drives the hydraulic valve to switch to the operating position. This setting can achieve the switching of the hydraulic valve simply by switching between no pressure and pressure in the control chamber, which helps to simplify the control logic.

[0022] 3. When any of the working seals / maintenance seals is engaged in the cavity under pressure, the medium coupling unit with a specific structure can cut off the oil supply to the ball valve control oil circuit, keeping the ball valve valve in the closed position and preventing it from opening, thus protecting the contact surface between the moving seal ring and the fixed seal ring from damage.

[0023] 4. The hydraulic control chamber of the fifth hydraulic control valve is connected to the mechanical overspeed protection device. When the unit overspeed protection device is activated, it can interlock and close the inlet ball valve to protect the unit's safety. The hydraulic control chamber of the sixth hydraulic control valve is connected to the tailgate fully open position stroke reversing valve. When the tailgate fully open position signal disappears, it can interlock and close the ball valve to protect the safety of the hydraulic equipment in the flow channel.

[0024] 5. This invention uses water as the hydraulic medium for a direct-opening ball valve. It should be noted that water has low viscosity, and natural water, in particular, contains minerals and other impurities, making it prone to microbial growth. This results in inadequate lubrication of the friction pairs, often leading to severe adhesive and abrasive wear on the friction surfaces, and even jamming, causing the hydraulic system to malfunction. Furthermore, the low viscosity of water makes it prone to severe leakage at the sealing points of hydraulic components, causing severe wire-drawing erosion and scouring of the sealing parts, and cavitation near the valve port. Due to these characteristics of water-hydraulic transmission, cartridge valves, directional valves, pressure regulating valves, and flow regulating valves widely used in oil systems cannot be easily converted for use in water-hydraulic systems.

[0025] To address this, the present invention specifically designs a cartridge valve suitable for hydraulic transmission with water media. This cartridge valve creatively incorporates an elastic sealing assembly and a self-resetting protection assembly. The elastic sealing assembly employs a structure combining an O-ring seal and a guide band, featuring two stepped annular grooves. The upper annular groove is wider and used to install the guide band. The O-ring seal is installed within the closed groove formed by the guide band and the lower annular groove. The groove depth of the upper step matches the guide band, providing strong support and constituting the lateral load-bearing portion of the guide band. This provides lateral support and lubrication for moving parts, effectively reducing friction on the valve core during movement. The O-ring seal provides elastic support to the guide band, ensuring close pressure between the guide band and the outer surface of the valve core, enhancing the sealing effect and achieving sealing and isolation of the media on both sides of the combined sealing element. This reduces leakage at the sealing point and mitigates wear and erosion. This guide-seal structure combines guiding and sealing functions, greatly improving the sealing effect of the guide band. For combinations that include both guide bands and sealing rings, this composite guide-seal structure significantly reduces axial space and equipment size, saving materials and facilitating installation. It is ideal for applications requiring a certain level of sealing in the guide area while allowing for minimal leakage, making it highly suitable for isolating the internal chambers of hydraulic valves. The self-resetting protection component keeps the valve core in the closed position when the control chamber loses pressure, solving the problem of cartridge valves failing to reset correctly after control source pressure loss. This allows the cartridge valve to automatically close the main circuit under extreme conditions, improving operational safety. Attached Figure Description

[0026] Figure 1 This is a structural diagram (I) of the present invention; Figure 2 This is a structural diagram (II) of the present invention; Figure 3 This is a cross-sectional view of a cartridge valve. Figure 4 This is a three-dimensional structural diagram of a cartridge valve; Figure 5This is a planar structural diagram of the elastic sealing assembly.

[0027] The following are labeled in the diagram: 1. Relay valve, 2. Hydraulic cartridge valve assembly, 3. First hydraulic directional valve, 4. Second hydraulic directional valve, 5. Third hydraulic directional valve, 6. Fourth hydraulic directional valve, 7. Fifth hydraulic valve, 8. Sixth hydraulic valve, 9. Oil medium control chamber, 10. Water medium constant pressure chamber, 11. Maintenance sealing control valve, 12. Oil medium constant pressure chamber, 13. Water medium control chamber, 14. Engagement / retraction solenoid valve, 15. First solenoid valve, 16. Second solenoid valve, 17. Third solenoid valve, 18. Valve body, 19. Valve cover, 20. Valve seat, 21. Valve core, 22. Valve cover, 23. Return spring, 24. Guide spring column, 25. Spring seat, 26. Piston, 27. Connection port, 28. Elastic sealing assembly, 29. O-ring seal, 30. Guide band, 31. Stepped annular groove. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0029] Example 1 like Figure 1 , 2 As shown, this embodiment provides a mixed ball valve control system based on oil and water media. The system specifically includes: The water-medium operating unit is configured to control the opening and closing of the inlet ball valve and the activation and deactivation of the maintenance seal using water media.

[0030] The oil medium control unit is configured to use oil medium to realize electro-hydraulic conversion and hydraulic protection logic functions; The media coupling unit employs a hydraulically controlled directional valve with complete isolation between the control chamber and the constant pressure chamber. It is configured to transmit pressure signals and perform logical linkages between oil and water media, as well as to enable and disable the working seal.

[0031] Specifically, the aforementioned water-medium operating unit includes: The relay 1, having an opening chamber and a closing chamber, is configured to control the opening and closing of the inlet ball valve.

[0032] The hydraulic cartridge valve assembly 2, controlled by the media coupling unit, is configured to connect to the opening chamber, closing chamber, pressurized water source, and drain port of the servo 1, respectively. It controls the connection of the opening chamber / closing chamber of the servo 1 to the pressurized water source / drainage. When the opening chamber is connected to the pressurized water source, the closing chamber is connected to the drain; when the closing chamber is connected to the pressurized water source, the opening chamber is connected to the drain. The hydraulic cartridge valve assembly 2 controls the operation of the servo 1 by controlling the inlet and outlet of the opening and closing chambers, thereby controlling the opening and closing of the ball valve.

[0033] The maintenance seal control valve 11, operated by a handle, is configured to connect to the maintenance seal engagement / disengagement chamber and a pressure water source respectively, and is used to control the engagement and disengagement of the maintenance seal.

[0034] Specifically, the aforementioned media coupling unit includes a first hydraulically controlled directional valve 3 for controlling the water pressure cartridge valve assembly 2, a second hydraulically controlled directional valve 4 for controlling the working seal, a third hydraulically controlled directional valve 5 for engaging and locking the working seal, and a fourth hydraulically controlled directional valve 6 for engaging and locking the maintenance seal. The first hydraulic directional valve 3 and the second hydraulic directional valve 4 both have an oil medium control chamber 9, a water medium constant pressure chamber 10, a water medium inlet, and two water medium outlets. The third hydraulic directional valve 5 and the fourth hydraulic directional valve 6 both have an oil medium constant pressure chamber 12 and a water medium control chamber 13. In this embodiment, the structures of each hydraulic directional valve are completely identical. The constant pressure chamber, control chamber, and input / output chamber of the hydraulic directional valve are completely physically isolated, and can be connected to different hydraulic working media such as oil and water. The oil medium control chamber 9, water medium constant pressure chamber 10, oil medium constant pressure chamber 12, and water medium control chamber 13 are named according to the different media introduced into the control chamber and constant pressure chamber.

[0035] The water medium constant pressure chamber 10 and water medium inlet of the first hydraulic directional valve 3, and the water medium constant pressure chamber 10 and water medium inlet of the second hydraulic directional valve 4 are all connected to a pressurized water source. The two water medium outlets of the first hydraulic directional valve 3 are connected to the water pressure cartridge valve group 2 to control the operation of the water pressure cartridge valve group 2. The two water medium outlets of the second hydraulic directional valve 4 are connected to the working seal to control the engagement or disengagement of the working seal. The oil medium control chamber 9 of the second hydraulic directional valve 4 is connected to a pressurized oil source through a solenoid valve 14, that is, the oil medium control chamber 9 of the second hydraulic directional valve 4 is connected to the oil port B of the solenoid valve 14, and the oil port P of the solenoid valve 14 is connected to the pressurized oil source.

[0036] The oil medium constant pressure chamber 12 of the third hydraulic directional valve 5 and the oil medium constant pressure chamber 12 of the fourth hydraulic directional valve 6 are both connected to a pressure oil source. The water medium control chamber 13 of the third hydraulic directional valve 5 is connected to the working seal input chamber. The water medium control chamber 13 of the fourth hydraulic directional valve 6 is connected to the maintenance seal input chamber. The oil port B of the third hydraulic directional valve 5 is connected to the oil port P of the fourth hydraulic directional valve 6. The oil port B of the fourth hydraulic directional valve 6 is connected to a pressure oil source. The oil medium control unit is connected between the oil medium control chamber 9 of the first hydraulic directional valve 3 and the oil port P of the third hydraulic directional valve 5.

[0037] The media coupling unit with the above-mentioned specific structure can achieve complete isolation of oil and water media through the control chamber and the constant pressure chamber, and effectively realize the transmission of pressure signals and logical linkage of oil and water media, thereby ensuring stable and reliable control of the ball valve.

[0038] In both the first hydraulic directional control valve 3 and the second hydraulic directional control valve 4, the cross-sectional area of ​​the oil medium control chamber 9 is larger than that of the water medium constant pressure chamber 10. The water medium constant pressure chamber 10 is connected to a relatively stable pressure water source via a pressure steel pipe. The hydraulic directional control valve has an automatic reset function for the oil medium control chamber 9 when it loses pressure. When the oil medium control chamber 9 is pressurized, it pushes the valve core 21 of the hydraulic directional control valve towards the water medium constant pressure chamber 10. For the first hydraulic directional control valve 3, the control pressure output from its two water medium outlets switches the water pressure cartridge valve group 2 to the open state of the relay 1. For the second hydraulic directional control valve 4, the control pressure output from its two water medium outlets switches the working seal to the engaged state. When the pressure in the oil medium control chamber 9 is removed, the hydraulic pressure in the water medium constant pressure chamber 10 will push the valve core 21 towards the oil medium control chamber 9 side of the hydraulically controlled directional valve. For the first hydraulically controlled directional valve 3, the control pressure output from its two water medium outlets will switch the water pressure cartridge valve group 2 to the closed state of the relay 1. For the second hydraulically controlled directional valve 4, the control pressure output from its two water medium outlets will switch the working seal to the exit state.

[0039] In the third hydraulic directional valve 5 and the fourth hydraulic directional valve 6, the cross-sectional area of ​​the oil medium constant pressure chamber 12 is smaller than that of the water medium control chamber 13. The oil medium constant pressure chamber 12 is connected to a relatively stable oil source. The third hydraulic directional valve 5 and the fourth hydraulic directional valve 6 have an automatic reset function for the water medium control chamber 13 when it loses pressure. When the water medium control chamber 13 is pressurized, the output ports P of the third hydraulic directional valve 5 and the fourth hydraulic directional valve 6 are connected to the input ports A to connect the return oil; the pressure oil source between their output ports P and the oil medium control chamber 9 of the first hydraulic directional valve 3 is cut off, inhibiting the opening of the ball valve. When the pressure in the water medium control chamber 13 is removed, for the third hydraulic control directional valve 5, its output port P is connected to the input port B to supply the pressure oil output from the output port P of the fourth hydraulic control directional valve 6, so that the ball valve control circuit has the opening conditions in the current stage; for the fourth hydraulic control directional valve 6, its output port P is connected to the input port B to supply the pressure oil source, so that the ball valve control circuit has the opening conditions in the current stage.

[0040] In this embodiment, the first hydraulic directional valve 3, the second hydraulic directional valve 4, the third hydraulic directional valve 5, and the fourth hydraulic directional valve 6 are designated as HV001, HV402, HV004, and HV005, respectively; the maintenance sealing control valve 11 is designated as MV408; and the engagement / disengagement solenoid valve 14 is designated as EV402. The specific structure and connection relationship of each valve are as follows: The medium inlet of MV408, the water medium inlet P and the water medium constant pressure chamber 10 of HV001, and the water medium inlet P and the water medium constant pressure chamber 10 of HV402 are all connected to a pressurized water source. The oil medium control chamber 9 of HV001 is connected to a pressurized oil source through an oil medium control unit and part of the medium coupling unit. The oil medium control chamber 9 of HV402 is connected to a pressurized oil source through oil ports B and P of EV402. Oil port P of EV402 and oil port B of HV005 are both connected to a pressurized oil source. Oil port B of EV402 is connected to the oil medium control chamber 9 of HV402 for controlling HV402.

[0041] MV408 is a ball valve maintenance seal control valve 11. Since the maintenance seal only needs to be engaged or disengaged during unit maintenance, it is a manual multi-way directional valve, and the operating medium is water.

[0042] HV402 is the second hydraulically controlled directional valve 4 for working seal control. Since the working seal needs to participate in the ball valve's start-up and shutdown process, a solenoid-driven hydraulically controlled directional valve is used. The operating chamber medium of HV402 is water, while the control chamber uses oil, so as to facilitate the use of a mature oil-medium solenoid valve to achieve electro-hydraulic conversion.

[0043] HV004 is a two-position three-way hydraulic directional valve. Its input port B is connected to the output port P of HV005. HV004 is used for working seal engagement and locking. Its water medium control chamber 13 is connected to the working seal engagement chamber. When the working seal engagement chamber is pressurized, the output port P of HV004 is connected to its port A to connect the return oil, causing the circuit between its output port P and the oil medium control chamber 9 of HV001 to lose pressure and lock the ball valve open.

[0044] HV005 is a two-position three-way hydraulic directional valve. Its output port P is connected to the input port B of HV004. HV005 is used for maintenance seal engagement and locking. Its hydraulic control is connected to the maintenance seal engagement chamber. When the maintenance seal engagement chamber is pressurized, the port P of HV005 is connected to its port A to connect the return oil, causing the circuit between its output port P and the oil medium control chamber 9 of HV001 to lose pressure and lock the ball valve open.

[0045] In this embodiment, the water pressure cartridge valve assembly 2 may adopt a structure including two cartridge valves or four cartridge valves, wherein, Figure 1The diagram shows a hydraulic cartridge valve assembly 2 with four cartridge valves connected in parallel, in pairs, and connected to the opening chamber, closing chamber, pressure water source, and drain port of the servo 1, respectively. When the opening chamber of the servo 1 is connected to the pressure water source through one set of cartridge valves, the drain of the other cartridge valve in the same group will be closed; simultaneously, the closing chamber is connected to the drain through another set of cartridge valves, and the other cartridge valve in the same group connected to the pressure water source will be closed. The cartridge valves have bidirectional flow capability, and their inlet and outlet ports can be partially or entirely interchanged. The opening / closing of the cartridge valves is achieved by the first hydraulically controlled directional valve 3 connected to its control chamber switching the pressure of its oil medium control chamber 9.

[0046] In this embodiment, four cartridge valves are designated as CV001, CV002, CV003, and CV004. The water inlets B of CV001 and CV004 are connected to the closing chamber of the servo motor 1; the water inlets B of CV002 and CV003 are connected to the opening chamber of the servo motor 1; the water inlets A of CV001 and CV002 are connected to a pressurized water source; and the water inlets A of CV003 and CV004 are connected to a drain outlet. The control chambers x and y of these four cartridge valves are connected in pairs to the two water medium output ports A and B of HV001. When the servo motor 1 is switched to the open state, the valve core of HV001 moves to the side of the water medium constant pressure chamber 10 under the oil pressure of the oil medium control chamber 9. The output water pressure control CV001 closes, cutting off the connection between the closed chamber of the servo motor 1 and the pressure water source. CV004 opens to connect the closed chamber of the servo motor 1 to the drainage. CV002 opens to connect the open chamber of the servo motor 1 to the pressure water source. CV003 closes to cut off the connection between the open chamber of the servo motor 1 and the drain outlet.

[0047] Figure 2 The diagram shows a hydraulic cartridge valve assembly 2 with two cartridge valves. This structure is equivalent to eliminating cartridge valves CV001 and CV004, retaining only CV002 and CV003. Based on this structure, the water inlet B of CV002 and CV003 is connected to the opening chamber of the servo motor 1; the water inlet A of CV002 is connected to the closing chamber of the servo motor 1 and connected to the pressure water source; and the water inlet A of CV003 is connected to the drain outlet. The control chambers x and y of each cartridge valve are connected to the two water medium output ports A and B of HV001, respectively. The control method of the four cartridge valves controlling the opening and closing process of the servo motor 1 is consistent and will not be described further.

[0048] In this embodiment, both the control chamber and the operating chamber of the cartridge valve use water as the medium. This not only prevents system failure caused by mutual leakage when using different media, but also has the advantages of simplifying the structure and improving reliability.

[0049] This embodiment does not limit the specific structure of the oil medium control unit; any existing structure that can achieve the above functions is acceptable.

[0050] The core concept of this embodiment lies in using water as the medium in the main operating circuit, leveraging its advantages of being clean, environmentally friendly, easy to maintain, and simple in structure. Meanwhile, the pilot control circuit uses oil as the medium, employing traditional and mature oil-based hydraulic components, thereby greatly improving the reliability of the control.

[0051] Example 2 Based on Example 1, this example further optimizes the structure of the oil medium control unit.

[0052] like Figure 1 , 2 As shown, the oil medium control unit includes a first solenoid valve 15, a second solenoid valve 16, a third solenoid valve 17, a fifth hydraulic control valve 7, and a sixth hydraulic control valve 8. The oil port P of the sixth hydraulic control valve 8 is connected to the third hydraulic control directional valve 5, the oil port B of the sixth hydraulic control valve 8 is connected to the oil port P of the fifth hydraulic control valve 7, the oil port B of the fifth hydraulic control valve 7 is connected to the oil port P of the third solenoid valve 17, the oil port B of the third solenoid valve 17 is connected to the oil port B of the first solenoid valve 15 and the oil port B of the second solenoid valve 16, the oil port P of the second solenoid valve 16 is connected to the oil port A of the first solenoid valve 15, and the oil port P of the first solenoid valve 15 is connected to the oil medium control chamber 9 of the first hydraulic control directional valve 3.

[0053] Furthermore, both the fifth hydraulic control valve 7 and the sixth hydraulic control valve 8 are two-position four-way hydraulic control directional valves. The hydraulic control chamber of the fifth hydraulic control valve 7 is connected to the mechanical overspeed protection device, and the hydraulic control chamber of the sixth hydraulic control valve 8 is connected to the tail brake fully open position stroke directional valve.

[0054] In this embodiment, the first solenoid valve 15, the second solenoid valve 16, and the third solenoid valve 17 are designated as EV001, EV002, and EV003, respectively, and the fifth hydraulic control valve 7 and the sixth hydraulic control valve 8 are designated as HV002 and HV003, respectively. The specific structure and connection relationship of each valve are as follows: EV001 and EV002 are normally energized solenoid valves with automatic reset function upon power failure. Port B of EV001 and EV002 are connected in parallel to port B of EV003. Port P of EV002 is connected to port A of EV001, and port A of EV002 is connected to the return oil. Port P of EV001 is connected to the oil medium control chamber 9 of HV001. This connection structure only allows port P of EV001 to connect to the return oil through EV001 and EV002 when both EV001 and EV002 are simultaneously de-energized, thus resetting HV001 and closing the ball valve.

[0055] EV003 is a two-position four-way solenoid valve. Port P of EV003 is connected to port B of HV002, and port A of EV003 is connected to the return oil. When EV003 is activated, the input oil pressure of EV001 and EV002 can be switched at the same time, thereby controlling the ball valve opening and closing.

[0056] HV002 is a two-position four-way hydraulically controlled directional valve. HV002 is used for mechanical overspeed protection. Its hydraulic control chamber is connected to a mechanical overspeed protection device. When the unit speed does not exceed the device's set value, its hydraulic control chamber remains pressurized, and port B of HV002 is connected to its port P. After an overspeed, its hydraulic control chamber loses pressure, and port B of HV002 switches to connection with the return oil, thereby causing the oil medium control chamber 9 of HV001 to lose pressure, interlocking and closing the ball valve.

[0057] HV003 is a two-position four-way hydraulically controlled directional valve. Its port B is connected to port P of HV002. HV003 is used for hydraulic protection during tail gate closure. Its hydraulic control chamber is connected to the tail gate fully open position stroke directional valve. When the tail gate is fully open, its hydraulic control chamber remains pressurized, and port B of HV003 is connected to its port P. After overspeed, its hydraulic control chamber loses pressure, and port B of HV003 switches to be connected to the return oil, thereby causing the oil medium control chamber 9 of HV001 to lose pressure, causing the ball valve to interlock and close.

[0058] In this embodiment, by setting up a first solenoid valve 15, a second solenoid valve 16, a third solenoid valve 17, a fifth hydraulic control valve 7, and a sixth hydraulic control valve 8 operated by hydraulic pressure between the oil medium control chamber 9 of the first hydraulic control directional valve 3 and the third hydraulic control directional valve 5, the output port of any stage can be switched to return oil, which can cause the oil medium control chamber 9 of the final first hydraulic control directional valve 3 to lose pressure and switch the cartridge valve to the working state of closing the relay 1, thereby improving the reliability and integration performance of the system.

[0059] Example 3 Based on Example 1 or Example 2, in order to overcome the problems of low viscosity of water medium, presence of minerals and other impurities, easy growth of microorganisms, and easy jamming, this example designs a cartridge valve specifically suitable for water medium, the specific structure of which is as follows: like Figure 3-5As shown, the cartridge valve includes a valve body 18, a valve cover 19 fixed at the upper end of the valve body 18, and two water inlets (A, B) at the lower end of the valve body 18. A valve seat 20 is fixed inside one of the water inlets. A valve core 21 that can move up and down is provided inside the valve body 18. The valve core 21 cooperates with the valve seat 20 to control the opening and closing of the water inlet. A piston 26 is fixed in the middle of the valve core 21. By cooperating with the valve body 18 and the end cover, the piston 26 can divide the inner cavity of the valve body 18 into two control chambers (x, y). The area of ​​the two control chambers acting on the axial movement hydraulic pressure of the valve core 21 is greater than the sum of the areas of the two water inlets acting on the valve core 21. A connection port 27 is opened on the valve body 18, which communicates with the two control chambers respectively. The cartridge valve is connected to the water medium output port of the first hydraulic control directional valve 3 through the connection port 27.

[0060] In this embodiment, the area of ​​the two control chambers acting on the axial hydraulic pressure of the valve core 21 is significantly larger than the sum of the areas of the two inlets acting on the valve core 21. Simultaneously, the guide ring provides effective support for the radial force on the valve core 21 and also provides lubrication and sealing, preventing dry friction between the valve core 21 and the valve body 18. Thus, even with minor impurities causing jamming or other factors increasing the resistance to the valve core 21's movement, the cartridge valve can still operate normally in water-medium conditions.

[0061] Furthermore, the valve body 18 is also equipped with two sets of elastic sealing components 28. One set of elastic sealing components 28 is located between the piston 26 and the valve body 18, and the other set of elastic sealing components 28 is located simultaneously between the valve core 21 and the valve body 18 and between the lower control chamber and the water inlet. Specifically, the elastic sealing component 28 includes an O-ring seal 29 and a guide band 30. The valve body 18 has a stepped annular groove 31 including a bottom groove and an outer groove. The width of the outer groove is greater than the width of the bottom groove. The O-ring seal 29 is installed in the bottom groove, and the guide band 30 is installed in the outer groove. The guide band 30 is made of PTFE mixed with copper powder. The width of the guide band 30 is greater than the width of the bottom O-ring seal 29. The steps in the stepped annular groove 31 can provide strong support for the guide band 30, forming the lateral load-bearing part of the guide band 30. The O-ring seal 29, as an elastic support, can reduce the gap between the guide band 30 and the valve core 21, thereby reducing leakage at the sealing part, reducing wear and erosion, and effectively improving its sealing effect.

[0062] This embodiment also considers the precise concentric shaft system of valve core 21, valve body 18, valve seat 20 and end cover. The valve body 18 adopts an integrally formed structure that combines the functions of valve sleeve and cover plate. The dimensions of valve core 21 and valve body 18 are ensured to be concentric by one-time clamping and machining. Valve seat 20 and end cover are required to have concentric inner / outer circular surfaces. A suitable gap is set in the soft sealing part to ensure that there is a reasonable gap between valve core 21 and the inner circular surface of valve body 18 and end cover during movement, to prevent direct friction between metal surfaces, reduce the movement resistance of valve core 21 and improve the reliability of cartridge valve.

[0063] Furthermore, considering that the valve seat 20 frequently bears the impact load of the valve core 21 during operation and serves as the isolation sealing surface between the two ports of the cartridge valve, this embodiment designs the valve seat 20 as a detachable component separate from the valve body 18. It is manufactured using high-performance materials to save costs and facilitate replacement. To ensure a tight seal between the valve core 21 and the sealing part of the valve seat 20 after closure, the sealing surface of the valve seat 20 is designed as a conical structure, with line contact at the sealing part. The assembly clearance between the valve seat 20 and the valve body 18 is appropriately increased, allowing the valve seat 20 to automatically concentricate under the impact of the valve core 21 during operation of the cartridge valve.

[0064] Furthermore, the upper part of the valve cover 19 is provided with a self-resetting protection assembly for keeping the valve core 21 in the closed position when the control chamber loses pressure. This self-resetting protection assembly includes a valve cover 22 fixed to the upper part of the valve cover 19. Inside the valve cover 22 are a return spring 23, a guide spring post 24, and a spring seat 25. The lower end of the guide spring post 24 is fixed to the valve core 21, and the upper end extends movably out of the valve cover 22. The spring seat 25 and the return spring 23 are both movably sleeved on the guide spring post 24, with the return spring 23 located between the spring seat 25 and the valve core 21. This self-resetting protection assembly automatically closes the cartridge valve when the control chamber loses pressure. It uses a high-strength return spring 23, which, in the fully closed position, can overcome the hydraulic pressure from its working chamber without relying on the hydraulic pressure of the control chamber, thus keeping the valve core 21 in the closed state. This solves the problem that the cartridge valve cannot correctly reset after the control chamber loses pressure, thereby closing the main circuit of the cartridge valve under extreme operating conditions and achieving safety protection for the control system and the ball valve.

[0065] It should be noted that the stiffness and compression of the return spring 23 are also matched with the stroke of the cartridge valve core 21. When the cartridge valve reaches its maximum fully open stroke, the compression of the return spring 23 reaches its limit. At this point, under the condition of the lowest hydraulic pressure in the opening and working chambers, it can overcome the closing effect of the spring force and keep the valve core 21 in the fully open position. In addition, the two ends of the return spring 23 abut against the spring seat 25 and the upper end face of the valve core 21, respectively. In the initial state of the cartridge valve being closed, the return spring 23 is pressed by the spring seat 25, providing initial clamping force.

[0066] In summary, the ball valve hydraulic control system provided in this embodiment, by adopting a cartridge valve with a specific structure, can directly use water medium to realize the opening and closing of the relay 1, and can be directly driven by the pressure water source in the pressure steel pipe. Only a small amount of pressure oil is needed for system logic control, and there is no need to set up a dedicated large hydraulic device to provide a driving pressure source for the relay 1. It has the advantages of simplified structure, reduced cost, space saving, avoidance of pollution, and easy maintenance.

[0067] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A mixed ball valve control system based on oil and water media, characterized in that... include: The water medium operating unit is configured to control the opening and closing of the inlet ball valve and the activation and deactivation of the maintenance seal using water medium. The oil medium control unit is configured to use oil medium to realize electro-hydraulic conversion and hydraulic protection logic functions; The medium coupling unit, which employs a hydraulically controlled directional valve that completely isolates the control chamber from the constant pressure chamber, is configured to realize the transmission of pressure signals and logical linkage between oil and water media.

2. The mixed ball valve control system based on oil and water media according to claim 1, characterized in that: The water medium operation unit includes: The relay (1) is configured to control the opening and closing of the inlet ball valve; The water pressure cartridge valve assembly (2), controlled by the medium coupling unit, is configured to connect to the opening chamber, the closing chamber, the pressure water source and the drain of the servo (1) respectively, and is used to control the connection of the opening chamber / closing chamber of the servo (1) to the pressure water source / drain. The maintenance seal control valve (11) is configured to connect to the maintenance seal engagement / disengagement chamber and the pressure water source, respectively.

3. A mixed ball valve control system based on oil and water media according to claim 2, characterized in that: The media coupling unit includes a first hydraulic directional valve (3), a second hydraulic directional valve (4), a third hydraulic directional valve (5), and a fourth hydraulic directional valve (6). The first hydraulic directional valve (3) and the second hydraulic directional valve (4) each have an oil medium control chamber (9) and a water medium constant pressure chamber (10). The third hydraulic directional valve (5) and the fourth hydraulic directional valve (6) each have an oil medium constant pressure chamber (12) and a water medium control chamber (13). The water medium constant pressure chamber (10) and the water medium inlet of the first hydraulic directional valve (3) and the second hydraulic directional valve (4) are connected to a pressurized water source. The water medium outlet of the first hydraulic directional valve (3) is connected to a water pressure cartridge valve assembly (2) to control the operation of the water pressure cartridge valve assembly (2). The water medium outlet of the second hydraulic directional valve (4) is connected to a working seal to control the operation of the working seal. The seal is engaged or disengaged; the oil medium control chamber (9) of the second hydraulic directional valve (4) is connected to the pressure oil source through the engagement / disengagement solenoid valve (14); the oil medium constant pressure chamber (12) of the third hydraulic directional valve (5) and the oil medium constant pressure chamber (12) of the fourth hydraulic directional valve (6) are both connected to the pressure oil source; the water medium control chamber (13) of the third hydraulic directional valve (5) is connected to the engagement chamber of the working seal; the water medium control chamber (13) of the fourth hydraulic directional valve (6) is connected to the engagement chamber of the maintenance seal; the oil port B of the third hydraulic directional valve (5) is connected to the oil port P of the fourth hydraulic directional valve (6); the oil port B of the fourth hydraulic directional valve (6) is connected to the pressure oil source; the oil medium control unit is connected between the oil medium control chamber (9) of the first hydraulic directional valve (3) and the oil port P of the third hydraulic directional valve (5).

4. A mixed ball valve control system based on oil and water media according to claim 3, characterized in that: In the first hydraulic directional valve (3) and the second hydraulic directional valve (4), the cross-sectional area of ​​the oil medium control chamber (9) is greater than the cross-sectional area of ​​the water medium constant pressure chamber (10); in the third hydraulic directional valve (5) and the fourth hydraulic directional valve (6), the cross-sectional area of ​​the oil medium constant pressure chamber (12) is smaller than the cross-sectional area of ​​the water medium control chamber (13).

5. A mixed ball valve control system based on oil and water media according to claim 3, characterized in that: The oil medium control unit includes a first solenoid valve (15), a second solenoid valve (16), a third solenoid valve (17), a fifth hydraulic control valve (7), and a sixth hydraulic control valve (8). The oil port P of the sixth hydraulic control valve (8) is connected to the third hydraulic control directional valve (5). The oil port B of the sixth hydraulic control valve (8) is connected to the oil port P of the fifth hydraulic control valve (7). The oil port B of the fifth hydraulic control valve (7) is connected to the oil port P of the third solenoid valve (17). The oil port B of the third solenoid valve (17) is connected to the oil port B of the first solenoid valve (15) and the oil port B of the second solenoid valve (16). The oil port P of the second solenoid valve (16) is connected to the oil port A of the first solenoid valve (15). The oil port P of the first solenoid valve (15) is connected to the oil medium control chamber (9) of the first hydraulic control directional valve (3).

6. A mixed ball valve control system based on oil and water media according to claim 5, characterized in that: The fifth hydraulic control valve (7) and the sixth hydraulic control valve (8) are both two-position four-way hydraulic control directional valves. The hydraulic control chamber of the fifth hydraulic control valve (7) is connected to the mechanical overspeed protection device, and the hydraulic control chamber of the sixth hydraulic control valve (8) is connected to the tail brake fully open position stroke directional valve.

7. A mixed ball valve control system based on oil and water media according to any one of claims 2-6, characterized in that: The water pressure cartridge valve group (2) includes two cartridge valves or four cartridge valves. When it includes four cartridge valves, the four cartridge valves are arranged in parallel in pairs and are respectively connected to the opening chamber of the relay (1), the closing chamber of the relay (1), the pressure water source and the drain port.

8. A mixed ball valve control system based on oil and water media according to claim 7, characterized in that: The cartridge valve includes a valve body (18), a valve cover (19) fixed at the upper end of the valve body (18), and two water inlets at the lower end of the valve body (18). A valve seat (20) is fixed inside one of the water inlets. A valve core (21) that can move up and down is provided inside the valve body (18). The valve core (21) cooperates with the valve seat (20) to control the opening and closing of the water inlet. A piston (26) is provided in the middle of the valve core (21) to divide the inner cavity of the valve body (18) into two control chambers, and the valve body (18) has a branch opening. The connection port (27) is connected to the control chamber, and the area of ​​the two control chambers acting on the axial motion hydraulic pressure of the valve core (21) is greater than the sum of the areas of the two water ports acting on the valve core (21); the valve body (18) is also provided with two sets of elastic sealing components (28), one set of elastic sealing components (28) is located between the piston (26) and the valve body (18), and the other set of elastic sealing components (28) is located between the valve core (21) and the valve body (18) and between the lower control chamber and the water port.

9. A mixed ball valve control system based on oil and water media according to claim 8, characterized in that: The elastic sealing assembly (28) includes an O-ring (29) and a guide strip (30). The guide strip (30) is made of PTFE mixed with copper powder. The valve body (18) has a stepped annular groove (31) including a bottom groove and an outer groove. The width of the outer groove is greater than the width of the bottom groove. The O-ring (29) is installed in the bottom groove and the guide strip (30) is installed in the outer groove.

10. A mixed ball valve control system based on oil and water media according to claim 8, characterized in that: The upper part of the valve cover (19) is provided with a self-resetting protection component for keeping the valve core (21) in the closed position when the control chamber loses pressure. The self-resetting protection component includes a valve cover (22) fixed on the upper part of the valve cover (19). The valve cover (22) is provided with a reset spring (23), a guide spring post (24) and a spring seat (25). The lower end of the guide spring post (24) is fixed on the valve core (21), and the upper end moves out of the valve cover (22). The spring seat (25) and the reset spring (23) are both movably sleeved on the guide spring post (24), and the reset spring (23) is located between the spring seat (25) and the valve core (21).

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