Electric servo pump control system for controlling opening degree of steam admission regulating valve of steam turbine
Through the electric servo pump control system, the connection between the hydraulic cylinder and the hydraulic pump and the pilot directional valve are used to solve the problem of slow response speed of the turbine steam inlet regulating valve, achieve the effect of rapid adjustment and reduced energy consumption, and improve the braking performance of the turbine.
Patent Information
- Application Number
- CN202423295411.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-27
AI Technical Summary
The existing turbine steam inlet regulating valve is driven by an oil motor, which has large throttling losses, high energy consumption, and slow response speed. In particular, the valve core of the regulating valve moves slowly when the turbine is braked, resulting in a long time for the turbine to stop steam intake.
An electric servo pump control system is adopted, which is connected to the hydraulic pump through a hydraulic cylinder. The hydraulic pump is driven by a motor as a bidirectional pump. Combined with a pilot directional valve and a spring box, rapid movement of the hydraulic cylinder piston is achieved, the action speed of the turbine steam inlet regulating valve is enhanced, and a closed hydraulic system is constructed through a relief valve and an accumulator to reduce energy consumption and improve response speed.
It realizes the rapid movement of the hydraulic cylinder piston, improves the action speed of the turbine steam inlet regulating valve, reduces energy consumption, and improves the quick closing response speed of the oil motor during turbine braking, thereby enhancing the reliability and safety of the system.
Smart Images
Figure CN223483013U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of hydrostatic drive systems, and in particular to an electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve. Background Art
[0002] A steam turbine inlet regulating valve is a device used to control the flow rate of fluids in steam turbine equipment. It is widely used in steam turbine equipment and is a key device for regulating the speed of steam turbines and the operating power of the unit.
[0003] Existing steam turbine inlet regulating valves are driven by hydraulic actuators, which use electro-hydraulic servo valves as their core control element. In a constant pressure source system, the flow rate into the hydraulic cylinder is adjusted according to the input signal from the electro-hydraulic servo valve, thereby driving the hydraulic cylinder to move. The piston rod of the hydraulic cylinder is connected to the valve core of the steam turbine inlet regulating valve. The extension and retraction of the hydraulic cylinder actuates the valve core, thereby controlling the opening degree of the regulating valve, and thus regulating the steam intake of the steam turbine, achieving the effect of controlling the steam turbine output power.
[0004] The aforementioned technical solutions have the following drawbacks: the electro-hydraulic servo valve has throttling losses and high energy consumption; when the turbine is braked, the hydraulic cylinder moves slowly, which in turn makes the valve core of the regulating valve move slowly, resulting in a longer time for the turbine to stop steam intake and a slower response speed. Utility Model Content
[0005] In order to reduce energy consumption and improve the fast-closing response speed of the hydraulic actuator during turbine braking, this application provides an electric servo pump control system for controlling the opening degree of the turbine inlet regulating valve.
[0006] The electric servo pump control system for controlling the opening degree of the steam inlet regulating valve of a steam turbine provided in this application adopts the following technical solution:
[0007] An electric servo pump control system for controlling the opening of a steam turbine inlet regulating valve includes an integrated valve group, a hydraulic pump, a motor, a hydraulic cylinder, and a spring box. The cylinder body of the hydraulic cylinder is connected to the spring box, and the hydraulic pump is connected to the hydraulic cylinder through the integrated valve group. The hydraulic cylinder is used to drive the steam turbine inlet regulating valve to operate. The motor is used to drive the pump shaft of the hydraulic pump to rotate. The hydraulic pump is used to extract hydraulic oil from one oil chamber in the hydraulic cylinder and pressurize it into another oil chamber. The two oil chambers in the hydraulic cylinder are connected through the integrated valve group. A pilot-operated directional valve is provided between the two oil chambers to control the connection between the two oil chambers.
[0008] By adopting the above technical solution, the hydraulic cylinder is connected to the hydraulic pump, which is driven by a motor. The hydraulic pump is configured as a bidirectional pump, which can extract hydraulic oil from one oil chamber of the hydraulic cylinder and press it into the other oil chamber, thereby moving the piston inside the hydraulic cylinder. This achieves the effect of controlling the extension and retraction of the hydraulic cylinder and reducing energy consumption. By connecting a spring to the piston rod of the hydraulic cylinder, the piston can compress the spring in the spring box when it moves, causing the spring to contract. When the pilot-operated directional valve is opened, the two oil chambers in the hydraulic cylinder are connected. At this time, the piston is pushed by the spring and moves. The hydraulic oil on both sides of the piston can flow freely through the pilot-operated directional valve, making the piston action speed of the hydraulic cylinder faster. This, in turn, increases the action speed of the turbine inlet regulating valve, thereby improving the fast-closing response speed of the hydraulic actuator during turbine braking.
[0009] Optionally, the integrated valve assembly includes a valve block with multiple holes forming a channel. The valve block is fixedly connected to the hydraulic cylinder, and a pilot-operated directional valve is mounted on the valve block.
[0010] By adopting the above technical solution, by opening holes in the valve block, hydraulic oil can flow in the channels inside the valve block. By installing the valve body on the valve block, the user can make the hydraulic oil flow in the valve block, thus achieving the effect of simplifying the structure.
[0011] Optionally, the valve block is provided with two relief valves and an accumulator. The relief valves and the accumulator are mounted on the valve block. Each oil chamber of the hydraulic cylinder is connected to the accumulator. A relief valve is provided between the accumulator and the hydraulic cylinder. Each oil chamber is connected to a relief valve.
[0012] By adopting the above technical solution, by setting an overflow valve on the valve block, the overflow valve is positioned between the accumulator and the hydraulic cylinder. When the oil pressure in any oil chamber of the hydraulic cylinder is too high, the pressure difference on both sides of the overflow valve becomes too large, causing the overflow valve core to move. This allows the hydraulic oil in the oil chamber of the hydraulic cylinder to flow into the accumulator, which can collect the hydraulic oil, thereby protecting the hydraulic cylinder and keeping the pressure in the hydraulic cylinder within the rated value.
[0013] Optionally, a check valve is connected between the accumulator and the hydraulic cylinder, and the check valve controls the hydraulic oil to flow from the accumulator into the hydraulic circuit where the hydraulic cylinder is located.
[0014] By adopting the above technical solution, a one-way valve is installed between the accumulator and the hydraulic cylinder, allowing the hydraulic oil to flow in one direction within the one-way valve.
[0015] Optionally, the hydraulic pump has three oil ports: the first oil port is connected to one oil chamber of the hydraulic cylinder, the second oil port is connected to another oil chamber of the hydraulic cylinder, and the third oil port is connected to the accumulator.
[0016] By adopting the above technical solution, multiple oil ports are set on the hydraulic pump to connect the hydraulic pump with the two oil chambers in the hydraulic cylinder. When the hydraulic pump is working, leakage is likely to occur. The leaked hydraulic oil is discharged to the accumulator through the third oil port. The accumulator serves to store the hydraulic oil, thus constructing a closed hydraulic system that does not require an external oil source.
[0017] Optionally, the check valve includes a first check valve, a second check valve, and a third check valve. The first check valve is located between the first oil port and the accumulator, the second check valve is located between the second oil port and the accumulator, and the third check valve is located between the third oil port and the accumulator. The first and second check valves control the hydraulic oil to flow unidirectionally from the accumulator into the hydraulic circuit where the hydraulic cylinder is located, and the third check valve controls the hydraulic oil to flow unidirectionally from the hydraulic pump into the accumulator.
[0018] By adopting the above technical solution, by setting a first check valve and a second check valve on the two oil chambers of the hydraulic cylinder, when the oil pressure in the accumulator is high, the hydraulic oil can push the check valve, so that the hydraulic oil can flow from the accumulator into the circuit where the hydraulic cylinder is located, achieving the effect of replenishing oil. When the hydraulic pump is working, leakage is likely to occur in the hydraulic pump. The leaked hydraulic oil is discharged to the accumulator through the third oil port, thus constructing a closed hydraulic system that does not require external oil source supply.
[0019] Optionally, a position sensor is provided inside the hydraulic cylinder to detect the position of the piston inside the hydraulic cylinder.
[0020] By adopting the above technical solution, and by setting a position sensor inside the hydraulic cylinder, the position sensor can detect the piston position inside the hydraulic cylinder. Combined with the control system, the pump speed can be adjusted to achieve the effect of precisely controlling the position of the hydraulic cylinder.
[0021] Optionally, two pilot-operated directional valves are provided between the two oil chambers of the hydraulic cylinder, and the two pilot-operated directional valves are connected in parallel.
[0022] By adopting the above technical solution, and by setting two pilot-operated directional valves between the oil chambers of the hydraulic cylinder to form a redundant design, the reliability of the fast-closing circuit is further improved.
[0023] In summary, the beneficial technical effects of this application are as follows:
[0024] 1. By connecting the hydraulic cylinder to the hydraulic pump, which is driven by a motor and configured as a bidirectional pump, the hydraulic pump can extract hydraulic oil from one oil chamber of the hydraulic cylinder and press it into the other oil chamber, thereby moving the piston inside the hydraulic cylinder. This achieves the effect of controlling the extension and retraction of the hydraulic cylinder and reducing energy consumption. By connecting a spring to the piston rod of the hydraulic cylinder, the piston can compress the spring in the spring box when it moves, causing the spring to contract. When the pilot-operated directional valve is opened, the two oil chambers in the hydraulic cylinder are connected. At this time, the piston is pushed by the spring and moves. The hydraulic oil on both sides of the piston can flow freely through the pilot-operated directional valve, making the piston of the hydraulic cylinder move faster. This, in turn, increases the operating speed of the turbine inlet regulating valve, thereby improving the fast-closing response speed of the hydraulic actuator during turbine braking.
[0025] 2. By installing a relief valve on the valve block, the relief valve is positioned between the accumulator and the hydraulic cylinder. When the oil pressure in any oil chamber of the hydraulic cylinder is too high, the pressure difference on both sides of the relief valve becomes too large, causing the valve core of the relief valve to move. This allows the hydraulic oil in the oil chamber of the hydraulic cylinder to flow into the accumulator. The accumulator can collect the hydraulic oil, thereby protecting the hydraulic cylinder and keeping the pressure inside the hydraulic cylinder within the rated value.
[0026] 3. By installing a position sensor inside the hydraulic cylinder, the position sensor can detect the piston position inside the hydraulic cylinder. Combined with the control system, the pump speed can be adjusted to achieve precise control of the hydraulic cylinder position. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application. Figure 1 .
[0028] Figure 2 This is a schematic diagram of the overall structure of an embodiment of this application. Figure 2 .
[0029] Figure 3 This is a hydraulic block diagram of an embodiment of this application.
[0030] Reference numerals: 1. Integrated valve assembly; 11. Valve block; 12. Check valve; 13. Relief valve; 14. Pilot-operated directional valve; 15. Accumulator; 2. Hydraulic pump; 3. Motor; 4. Hydraulic cylinder; 41. First oil chamber; 42. Second oil chamber; 5. Spring box. DETAILED DESCRIPTION
[0031] The present application will be further described in detail below with reference to the accompanying drawings.
[0032] This application discloses an electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve, referring to... Figure 1 , Figure 2 and Figure 3The system includes an integrated valve assembly 1, a hydraulic pump 2, a motor 3, a hydraulic cylinder 4, and a spring box 5. The hydraulic cylinder 4 is connected to the spring box 5, which supports the hydraulic cylinder 4. The integrated valve assembly 1 is mounted on the hydraulic cylinder 4, and the hydraulic pump 2 is connected to the integrated valve assembly 1. The motor 3 is connected to the hydraulic pump 2. The motor 3 drives the pump shaft of the hydraulic pump 2 to rotate, thereby causing the hydraulic pump 2 to drive the hydraulic cylinder 4, allowing the piston rod of the hydraulic cylinder 4 to slide within the cylinder. The piston rod of the hydraulic cylinder 4 is connected to the turbine inlet steam regulating valve. The spring box 5 is used to drive the piston rod of the hydraulic cylinder 4, enabling the hydraulic cylinder 4 to close the turbine inlet steam regulating valve, thus accelerating the response speed of the turbine inlet steam regulating valve, reducing the probability of fluid leakage within the regulating valve, and improving safety.
[0033] Reference Figure 1 , Figure 2 and Figure 3 The integrated valve assembly 1 includes a valve block 11, three check valves 12, two relief valves 13, two pilot-operated directional valves 14, and an accumulator 15. The check valves 12 and relief valves 13 are mounted on the valve block 11, which is then mounted on the hydraulic cylinder 4. The valve block 11 is made of a high-strength metal block and has multiple holes forming oil passages. The hydraulic cylinder 4 forms a first oil chamber 41 and a second oil chamber 42, which are located on both sides of the piston inside the cylinder. The hydraulic pump 2 is configured as a bidirectional pump, and the hydraulic pump 2 has a first oil port, a second oil port and a third oil port. The first oil port is connected to the first oil chamber 41 through the valve block 11, and the second oil port is connected to the second oil chamber 42 through the valve block 11. When the hydraulic pump 2 is driven by the motor 3, it can draw out the hydraulic oil in one cavity and press it into the other cavity, thereby moving the piston in the cylinder and causing the hydraulic cylinder 4 to move.
[0034] Reference Figure 1 , Figure 2 and Figure 3The first port of hydraulic pump 2 is connected to the first oil chamber 41 of hydraulic cylinder 4, and the second port of hydraulic pump 2 is connected to the second oil chamber 42 of hydraulic cylinder 4. A check valve 12 and a relief valve 13 are connected in parallel in the oil circuit between accumulator 15 and hydraulic cylinder 4. The third port of hydraulic pump 2 is connected to accumulator 15, and a filter and check valve 12 are installed between hydraulic pump 2 and accumulator 15. When the oil pressure in hydraulic cylinder 4 is greater than the threshold value set by relief valve 13, relief valve 13 is activated, and hydraulic oil in hydraulic cylinder 4 can flow into accumulator 15 through relief valve 13. When the oil pressure in hydraulic cylinder 4 is too low and the oil pressure in accumulator 15 is too high, hydraulic oil in accumulator 15 can flow back to the circulation loop of hydraulic cylinder 4 and hydraulic pump 2 through check valve 12, achieving the effect of replenishing oil in the hydraulic system. During the operation of hydraulic pump 2, hydraulic oil is prone to leakage when it enters hydraulic pump 2 through the first or second oil port. The leaked oil flows out from the third oil port and enters accumulator 15. When the leaked oil flows, it enters accumulator 15 through check valve 12. Accumulator 15 plays the role of collecting leaked oil. When the oil pressure in accumulator 15 is higher than the oil pressure in the oil chamber of hydraulic cylinder 4, the hydraulic oil causes check valve 12 between hydraulic pump 2 and hydraulic cylinder 4 to be activated, thereby allowing hydraulic oil to flow back from accumulator 15 to hydraulic cylinder 4.
[0035] Reference Figure 1 , Figure 2 and Figure 3 Two pilot-operated directional valves 14 are connected in parallel and positioned in the oil circuit connecting the first oil chamber 41 and the second oil chamber 42. The pilot-operated directional valves 14 are solenoid valves. When both pilot-operated directional valves 14 are open, the first oil chamber 41 and the second oil chamber 42 are connected. At this time, the pressure on both sides of the piston in the hydraulic cylinder 4 is equal, and the spring box 5 can release elastic potential energy, thereby causing the piston rod in the hydraulic cylinder 4 to move rapidly, which in turn causes the turbine inlet regulating valve to act quickly and adjust to the closed state. By setting two pilot-operated directional valves 14 to form a redundant design, the reliability of the fast-closing circuit can be further improved.
[0036] Reference Figure 1 A position sensor is installed inside the hydraulic cylinder 4. The position sensor is used to detect the position of the piston inside the hydraulic cylinder 4. When the piston inside the cylinder moves to the end of the cylinder, the position sensor outputs an electrical signal, which facilitates the control of the speed, reverse, or stop the operation of the hydraulic pump 2.
[0037] The implementation principle of this application embodiment is as follows: By setting an integrated valve group 1 on the hydraulic cylinder 4 and a hydraulic pump 2 on the integrated valve group 1, the motor 3 drives the hydraulic pump 2 to operate, thereby causing the hydraulic pump 2 to draw hydraulic oil from one oil chamber of the hydraulic cylinder 4 and press it into another oil chamber, enabling the hydraulic cylinder 4 to extend and retract. By setting a one-way valve 12 and a relief valve 13 on the valve block 11, the relief valve 13 protects the hydraulic cylinder 4. When the oil pressure in the first oil chamber 41 or the second oil chamber 42 of the hydraulic cylinder 4 is too high, the relief valve 13 can automatically operate and restore the hydraulic pressure. Hydraulic oil in cylinder 4 flows into accumulator 15. Hydraulic oil in accumulator 15 can automatically flow back to the hydraulic circuit between hydraulic cylinder 4 and hydraulic pump 2 through check valve 12 to achieve oil replenishment. By setting an oil circuit between the two oil chambers of hydraulic cylinder 4, and setting two pilot-operated directional valves 14 in the oil circuit, when the pilot-operated directional valve 14 is opened, the first oil chamber 41 and the second oil chamber 42 are connected. At this time, the piston can move in the cylinder body, and the spring box 5 can drive the piston to reset, thereby causing the turbine inlet steam regulating valve connected to hydraulic cylinder 4 to move quickly to the closed position.
[0038] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.
Claims
1. An electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve, characterized in that: The system includes an integrated valve assembly (1), a hydraulic pump (2), a motor (3), a hydraulic cylinder (4), and a spring box (5). The cylinder body of the hydraulic cylinder (4) is connected to the spring box (5). The hydraulic pump (2) is connected to the hydraulic cylinder (4) through the integrated valve assembly (1). The hydraulic cylinder (4) is used to drive the turbine inlet regulating valve. The motor (3) is used to drive the pump shaft of the hydraulic pump (2) to rotate. The hydraulic pump (2) is used to extract the hydraulic oil in one oil chamber of the hydraulic cylinder (4) and press it into another oil chamber. The two oil chambers in the hydraulic cylinder (4) are connected through the integrated valve assembly (1). A pilot-operated directional valve (14) is provided between the two oil chambers. The pilot-operated directional valve (14) is used to control the connection between the two oil chambers.
2. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 1, characterized in that: The integrated valve group (1) includes a valve block (11), which has multiple holes forming a channel. The valve block (11) is fixedly connected to the hydraulic cylinder (4), and a pilot-operated directional valve (14) is installed on the valve block (11).
3. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 2, characterized in that: The valve block (11) is provided with two relief valves (13) and an accumulator (15). The relief valves (13) and the accumulator (15) are installed on the valve block (11). Each oil chamber of the hydraulic cylinder (4) is connected to the accumulator (15). A relief valve (13) is provided between the accumulator (15) and the hydraulic cylinder (4). Each oil chamber is connected to a relief valve (13).
4. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 3, characterized in that: A check valve (12) is connected between the accumulator (15) and the hydraulic cylinder (4). The check valve (12) controls the hydraulic oil to flow from the accumulator (15) into the hydraulic circuit where the hydraulic cylinder (4) is located.
5. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 4, characterized in that: The hydraulic pump (2) has three oil ports. The first oil port is connected to one oil chamber of the hydraulic cylinder (4), the second oil port is connected to another oil chamber of the hydraulic cylinder (4), and the third oil port is connected to the accumulator (15).
6. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 5, characterized in that: The one-way valve (12) includes a first one-way valve, a second one-way valve and a third one-way valve. The first one-way valve is located between the first oil port and the accumulator (15), the second one-way valve is located between the second oil port and the accumulator (15), and the third one-way valve is located between the third oil port and the accumulator (15). The first one-way valve and the second one-way valve control the hydraulic oil to flow from the accumulator (15) into the hydraulic circuit where the hydraulic cylinder (4) is located in one direction, and the third one-way valve controls the hydraulic oil to flow from the hydraulic pump (2) into the accumulator (15) in one direction.
7. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 1, characterized in that: A position sensor is installed inside the hydraulic cylinder (4), which is used to detect the position of the piston inside the hydraulic cylinder (4).
8. The electric servo pump control system for controlling the opening degree of a steam turbine inlet regulating valve according to claim 1, characterized in that: Two pilot-operated directional valves (14) are provided between the two oil chambers of the hydraulic cylinder (4), and the two pilot-operated directional valves (14) are connected in parallel.