Cylinder structure and control method for valve actuator of high-temperature wind tunnel liquid oxygen system

Abstract

This invention belongs to the field of high-temperature wind tunnel testing technology, and discloses a cylinder structure and control method for a valve actuator in a high-temperature wind tunnel liquid oxygen system. The cylinder structure of the valve actuator in the high-temperature wind tunnel liquid oxygen system employs a dual-cylinder structure that can be controlled independently to control the opening and closing of the valve. Through pressure feedback and a cylinder control system, downstream pressure feedback is applied to both cylinders. The control method of the cylinder structure of the valve actuator in the high-temperature wind tunnel liquid oxygen system controls the intake and exhaust modes of the upper and lower cylinders through downstream pressure feedback, enabling the valve actuator to operate with either a single or dual cylinder. This effectively reduces the stress on the sealing surface while meeting the sealing pressure requirements, thus meeting the usage requirements of valves in high-temperature wind tunnel liquid oxygen systems, extending valve service life, and possessing practical engineering value.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature wind tunnel testing technology, specifically relating to the cylinder structure and control method for valve actuators in liquid oxygen systems of high-temperature wind tunnels. Background Technology

[0002] The high-temperature wind tunnel liquid oxygen supply system mainly consists of two high-pressure liquid oxygen storage tanks (tank A and tank B), two liquid oxygen pneumatic shut-off valves (valve A and valve B), and supply pipelines. Valve A and valve B are respectively located at the bottom of tank A and tank B, and then connected to a main supply pipeline to supply oxygen externally. Supply can be achieved by controlling the opening and closing of the valves at the bottom of the tanks, either by a single tank or by two tanks in parallel. Therefore, the pneumatic shut-off valve is the core control component of the high-temperature wind tunnel liquid oxygen supply system. The pneumatic shut-off valve is usually composed of a pneumatic actuator, valve body, valve core, etc. Among them, the cylinder is an important component of the pneumatic actuator, and the cylinder structure and its control method directly determine the reliability of the valve seal.

[0003] The operating pressure of the liquid oxygen system in the high-temperature wind tunnel reaches as high as 30 MPa, requiring the pneumatic shut-off valve to maintain good sealing performance under high pressure. Therefore, the pneumatic shut-off valve is selected and designed based on the maximum cylinder force and the sealing specific pressure of the sealing surface. When the pneumatic shut-off valve is under a large sealing specific pressure for a long time, it will have a significant impact on the sealing performance of the sealing surface and the service life of the valve.

[0004] Currently, there is an urgent need to develop a cylinder structure and control method for valve actuators in high-temperature wind tunnel liquid oxygen systems. Summary of the Invention

[0005] One technical problem to be solved by the present invention is to provide a cylinder structure for a valve actuator in a liquid oxygen system of a high-temperature wind tunnel. Another technical problem to be solved by the present invention is to provide a control method for the cylinder structure for a valve actuator in a liquid oxygen system of a high-temperature wind tunnel, so as to overcome the defects of the prior art.

[0006] The cylinder structure for a valve actuator in a high-temperature wind tunnel liquid oxygen system of the present invention includes an upper cylinder and a lower cylinder connected in series. The top cover of the upper cylinder is the upper cylinder cover. The upper cylinder and the lower cylinder are separated by a middle cylinder cover. The bottom cover of the lower cylinder is the lower cylinder cover. The upper cylinder and the lower cylinder are fixedly connected by several bolts running through the circumference. A piston rod runs from bottom to top along the central axis of the upper cylinder and the lower cylinder. Two pistons are mounted on the piston rod, which are parallel to each other. One piston is located in the upper cylinder, and the upper section of the corresponding piston rod is guided to the middle cylinder head by a guide copper sleeve I. The other piston is located in the lower cylinder, and the lower section of the corresponding piston rod is guided to the lower cylinder head by a guide copper sleeve II. The piston ring is fixed to the corresponding piston by a piston pressing plate, the piston is fixed to the piston rod by a shaft retaining ring, and the piston ring is sealed with the upper cylinder and the lower cylinder by an O-ring respectively.

[0007] Further, the upper cylinder head is provided with 1 upper cylinder exhaust port and 1 upper cylinder air intake and exhaust port. The outlet of the upper cylinder exhaust port of the upper cylinder head is connected to a two-position two-way normally open solenoid valve K2; the middle cylinder head is provided with one upper cylinder air intake and exhaust port and one lower cylinder air intake and exhaust port. The upper cylinder air intake and exhaust port of the middle cylinder head is connected to a two-position five-way solenoid valve G1, and the lower cylinder air intake and exhaust port of the middle cylinder head is connected to a two-position five-way solenoid valve G2; the lower cylinder head is provided with one lower cylinder air intake and exhaust port, and the lower cylinder air intake and exhaust port of the lower cylinder head is connected to the two-position five-way solenoid valve G2; a two-position two-way normally closed solenoid valve K1 is connected between the two-position five-way solenoid valve G1 and the two-position five-way solenoid valve G2, and a nitrogen intake port is opened between the two-position two-way normally closed solenoid valve K1 and the two-position five-way solenoid valve G2.

[0008] Further, the high-temperature wind tunnel liquid oxygen system consists of 2 high-pressure liquid oxygen storage tanks including storage tank A and storage tank B, and 2 liquid oxygen pneumatic stop valves including pneumatic stop valve A and pneumatic stop valve B. The pneumatic stop valve A and the pneumatic stop valve B are respectively arranged at the bottoms of the storage tank A and the storage tank B. The pneumatic stop valve A and the pneumatic stop valve B are connected in parallel to the supply pipeline. A pressure transmitter is connected to the supply pipeline, and the opening of the supply pipeline is the output port of the high-temperature wind tunnel liquid oxygen system.

[0009] The control method for the cylinder structure of the valve actuator of the high-temperature wind tunnel liquid oxygen system of the present invention includes the following contents: a. Before the high-temperature wind tunnel runs, set the critical pressure for single-cylinder and double-cylinder switching as P0. When storage tank A supplies alone, open the pneumatic stop valve A and close the pneumatic stop valve B at the same time. b. When the high-temperature wind tunnel is running, pressurize storage tank A together with the supply pipeline, and measure the pressure of the high-temperature wind tunnel liquid oxygen system as P with a pressure transmitter. When P < P0, the two-position two-way normally closed solenoid valve K1 is powered off, and the two-position two-way normally open solenoid valve K2 is powered off. It is in the single-cylinder mode. By controlling the power on and off of the two-position five-way solenoid valve G2 to control the intake and exhaust of the lower cylinder, the piston ring action is realized to drive the piston rod action, thereby realizing the opening and closing of the valve. When P > P0, the two-position two-way normally closed solenoid valve K1 is powered on, and the two-position two-way normally open solenoid valve K2 is powered on. It is in the double-cylinder mode. By controlling the power on and off of the two-position five-way solenoid valve G2 and the two-position five-way solenoid valve G1 at the same time to control the intake and exhaust of the upper cylinder and the lower cylinder, the piston ring action is realized to drive the piston rod action, thereby realizing the opening and closing of the valve. c. After the high-temperature wind tunnel runs, depressurize storage tank A together with the supply pipeline, and the pneumatic stop valve B returns to the single-cylinder mode again.

[0010] The cylinder structure and control method for valve actuators in high-temperature wind tunnel liquid oxygen systems of this invention employs a dual-cylinder structure valve actuator that can be controlled independently to control the opening and closing of the valves. Through pressure feedback and a cylinder control system, downstream pressure feedback is applied to the dual cylinders. When the high-temperature wind tunnel liquid oxygen system uses only storage tank A for supply, valve A at the bottom of storage tank A is in the open state, and valve B is in the closed state. During operation, the pressure of storage tank A and its downstream pipeline will vary from 0-30 MPa, and the downstream pressure of valve B will change accordingly. Considering the sealing reliability and service life of valve B, the actuator cylinder is equipped with both single-cylinder and dual-cylinder operating modes, with a set critical pressure P0. When the downstream pressure of valve B equals P0, valve B operates in single-cylinder mode; when the downstream pressure of valve B is greater than P0, valve B operates in dual-cylinder mode.

[0011] In summary, the cylinder structure and control method of the present invention for valve actuators in high-temperature wind tunnel liquid oxygen systems control the intake and exhaust modes of the upper and lower cylinders through downstream pressure feedback of the valve, enabling the valve actuator to operate with a single or double cylinder. While meeting the sealing pressure requirements, it effectively reduces the stress on the sealing surface, thus meeting the usage requirements of valves in high-temperature wind tunnel liquid oxygen systems, extending the service life of the valves, and has practical engineering value. Attached Figure Description

[0012] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0013] Figure 1 This is a schematic diagram (front view) of the cylinder structure of the valve actuator for a high-temperature wind tunnel liquid oxygen system according to the present invention. Figure 2 This is a schematic diagram (cross-sectional view) of the cylinder structure of the valve actuator for the liquid oxygen system in a high-temperature wind tunnel according to the present invention. Figure 3 Schematic diagram of the liquid oxygen supply system for high-temperature wind tunnels.

[0014] In the diagram, 1. Lower cylinder head; 2. Lower cylinder; 3. Middle cylinder head; 4. Upper cylinder; 5. Upper cylinder head; 6. Two-position five-way solenoid valve G1; 7. Two-position two-normally closed solenoid valve K1; 8. Two-position five-way solenoid valve G2; 9. Two-position two-normally open solenoid valve K2; 10. Guide copper sleeve I; 11. O-ring; 12. Piston ring; 13. Piston; 14. Piston rod; 15. Guide copper sleeve II; 16. Shaft retaining ring; 17. Piston pressure plate; 18. Pneumatic shut-off valve A; 19. Storage tank A; 20. Storage tank B; 21. Pressure transmitter; 22. Supply pipeline; 23. Pneumatic shut-off valve B. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] Example: Figure 1 , Figure 2 As shown, the cylinder structure for the valve actuator of the liquid oxygen system in the high temperature wind tunnel in this embodiment includes an upper cylinder 4 and a lower cylinder 2 connected in series. The top cover of the upper cylinder 4 is the upper cylinder cover 5. The upper cylinder 4 and the lower cylinder 2 are separated by a middle cylinder cover 3. The bottom cover of the lower cylinder 2 is the lower cylinder cover 1. The upper cylinder 4 and the lower cylinder 2 are fixedly connected by several bolts that run through the circumference. A piston rod 14 runs from bottom to top along the central axis of the upper cylinder 4 and the lower cylinder 2. Two pistons 13 are mounted on the piston rod 14, which are parallel to each other. One piston 13 is located in the upper cylinder 4, and the upper section of the corresponding piston rod 14 is guided to the middle cylinder head 3 by a guide copper sleeve I 10. The other piston 13 is located in the lower cylinder 2, and the lower section of the corresponding piston rod 14 is guided to the lower cylinder head 1 by a guide copper sleeve II 15. The piston ring 12 is fixed to the corresponding piston 13 by the piston pressure plate 17, and the piston 13 is fixed to the piston rod 14 by the shaft retaining ring 16. The piston ring 12 is sealed with the upper cylinder 4 and the lower cylinder 2 by the O-ring 11.

[0017] Furthermore, the upper cylinder head 5 is provided with one upper cylinder exhaust port and one upper cylinder inlet / exhaust port. The outlet of the upper cylinder exhaust port of the upper cylinder head 5 is connected to a two-position two-way normally open solenoid valve K29. The middle cylinder head 3 is provided with one upper cylinder inlet / exhaust port and one lower cylinder inlet / exhaust port. The upper cylinder inlet / exhaust port of the middle cylinder head 3 is connected to a two-position five-way solenoid valve G16, and the lower cylinder inlet / exhaust port of the middle cylinder head 3 is connected to a two-position five-way solenoid valve G28. The lower cylinder head 1 is provided with one lower cylinder inlet / exhaust port, and the lower cylinder inlet / exhaust port of the lower cylinder head 1 is connected to a two-position five-way solenoid valve G28. A two-position two-way normally closed solenoid valve K17 is connected between the two-position two-way normally closed solenoid valve G16 and the two-position five-way solenoid valve G28. A nitrogen inlet is opened between the two-position two-way normally closed solenoid valve K17 and the two-position five-way solenoid valve G28.

[0018] Further, as Figure 3 shown, the high-temperature wind tunnel liquid oxygen system includes two high-pressure liquid oxygen storage tanks, namely storage tank A19 and storage tank B20, and two pneumatic liquid oxygen stop valves, namely pneumatic stop valve A18 and pneumatic stop valve B23. Pneumatic stop valve A18 and pneumatic stop valve B23 are respectively arranged at the bottoms of storage tank A19 and storage tank B20. Pneumatic stop valve A18 and pneumatic stop valve B23 are connected in parallel to the supply pipeline 22. A pressure transmitter 21 is connected to the supply pipeline 22. The opening of the supply pipeline 22 is the output port of the high-temperature wind tunnel liquid oxygen system.

[0019] The control method for the cylinder structure of the valve actuator of the high-temperature wind tunnel liquid oxygen system in this embodiment includes the following contents: a. Before the high-temperature wind tunnel runs, set the critical pressure for single-cylinder and double-cylinder switching as P0. When storage tank A19 supplies alone, open pneumatic stop valve A18 and close pneumatic stop valve B23 simultaneously. b. When the high-temperature wind tunnel is running, pressurize storage tank A19 together with the supply pipeline 22, and use the pressure transmitter 21 to measure the pressure of the high-temperature wind tunnel liquid oxygen system as P. As shown in Table 1, when P < P0, the two-position two-way normally closed solenoid valve K17 is de-energized, and the two-position two-way normally open solenoid valve K29 is de-energized, in the single-cylinder mode. Through the energization and de-energization control of the five-way two-position solenoid valve G28, the lower cylinder 2 intakes and exhausts air, realizing the movement of the piston ring 12 to drive the movement of the piston rod 14, thereby realizing the opening and closing of the valve. When P > P0, the two-position two-way normally closed solenoid valve K17 is energized, and the two-position two-way normally open solenoid valve K29 is energized, in the double-cylinder mode. Through the simultaneous energization and de-energization control of the five-way two-position solenoid valve G28 and the five-way two-position solenoid valve G16, the upper cylinder 4 and the lower cylinder 2 intake and exhaust air, realizing the movement of the piston ring 12 to drive the movement of the piston rod 14, thereby realizing the opening and closing of the valve. c. After the high-temperature wind tunnel operation ends, depressurize storage tank A19 together with the supply pipeline 22, and pneumatic stop valve B23 returns to the single-cylinder mode.

[0020] Table 1 Corresponding table of valve actuator working status and cylinder working status ; Note: + indicates energized, - indicates de-energized.

[0021] Although the embodiments of the present invention have been disclosed as above, they are not limited to only the applications listed in the specification and the embodiments. For those familiar with the art, without departing from the principle of the present invention, all the features disclosed in the present invention, or all the steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way. The present invention is not limited to the specific details and the illustrated examples here.

Claims

1. A cylinder structure for a valve actuator in a high-temperature wind tunnel liquid oxygen system, characterized in that, The cylinder structure of the valve actuator of the liquid oxygen system includes an upper cylinder (4) and a lower cylinder (2) connected in series. The top cover of the upper cylinder (4) is the upper cylinder cover (5). The upper cylinder (4) and the lower cylinder (2) are separated by a middle cylinder cover (3). The bottom cover of the lower cylinder (2) is the lower cylinder cover (1). The upper cylinder (4) and the lower cylinder (2) are fixedly connected by several bolts running through the circumference. The piston rod (14) runs from bottom to top along the central axis of the upper cylinder (4) and the lower cylinder (2). Two pistons (13) are mounted on the piston rod (14) in parallel. One piston (13) is located in the upper cylinder (4), and the upper section of the corresponding piston rod (14) is guided to the middle cylinder head (3) by the guide copper sleeve I (10). The other piston (13) is located in the lower cylinder (2), and the lower section of the corresponding piston rod (14) is guided to the lower cylinder head (1) by the guide copper sleeve II (15). The piston ring (12) is fixed to the corresponding piston (13) by the piston pressure plate (17), and the piston (13) is fixed to the piston rod (14) by the shaft retaining ring (16). The piston ring (12) is sealed with the upper cylinder (4) and the lower cylinder (2) by O-rings (11).

2. The cylinder structure for a valve actuator in a high-temperature wind tunnel liquid oxygen system according to claim 1, characterized in that, The upper cylinder head (5) is provided with one upper cylinder exhaust port and one upper cylinder inlet and exhaust port. The outlet of the upper cylinder exhaust port of the upper cylinder head (5) is connected to a two-position two-way normally open solenoid valve K2 (9). The middle cylinder head (3) is provided with one upper cylinder inlet and exhaust port and one lower cylinder inlet and exhaust port. The upper cylinder inlet and exhaust port of the middle cylinder head (3) is connected to a two-position five-way solenoid valve G1 (6), and the lower cylinder inlet and exhaust port of the middle cylinder head (3) is connected to a two-position five-way solenoid valve G2 (8). The lower cylinder head (1) is provided with one lower cylinder inlet and exhaust port. The lower cylinder inlet and exhaust port of the lower cylinder head (1) is connected to a two-position five-way solenoid valve G2 (8). A two-position two-way normally closed solenoid valve K1 (7) is connected between the two-position two-way normally closed solenoid valve K1 (7) and the two-position five-way solenoid valve G2 (8). A nitrogen inlet is opened between the two-position two-way normally closed solenoid valve K1 (7) and the two-position five-way solenoid valve G2 (8).

3. The cylinder structure for a valve actuator in a high-temperature wind tunnel liquid oxygen system according to claim 2, characterized in that, The high-temperature wind tunnel liquid oxygen system consists of two high-pressure liquid oxygen storage tanks, including tank A (19) and tank B (20), and two liquid oxygen actuated shut-off valves, including actuated shut-off valve A (18) and actuated shut-off valve B (23). Actuated shut-off valve A (18) and actuated shut-off valve B (23) are respectively installed at the bottom of tank A (19) and tank B (20). Actuated shut-off valve A (18) and actuated shut-off valve B (23) are connected in parallel to the supply pipeline (22). A pressure transmitter (21) is connected to the supply pipeline (22). The opening of the supply pipeline (22) is the output port of the high-temperature wind tunnel liquid oxygen system.

4. A control method for a cylinder structure used in a valve actuator of a liquid oxygen system in a high-temperature wind tunnel, comprising the cylinder structure described in claim 3 for a valve actuator of a liquid oxygen system in a high-temperature wind tunnel, characterized in that... Includes the following: a. Before the high-temperature wind tunnel is in operation, the critical pressure for switching between single cylinder and double cylinder is set to P0. When the storage tank A (19) supplies the gas alone, the pneumatic shut-off valve A (18) is opened and the pneumatic shut-off valve B (23) is closed. b. When the high-temperature wind tunnel is operating, the storage tank A (19) together with the supply pipeline (22) is pressurized, and the pressure of the liquid oxygen system in the high-temperature wind tunnel is measured as P by the pressure transmitter (21); When P < P0, the two-position two-way normally closed solenoid valve K1 (7) is de-energized, and the two-position two-way normally open solenoid valve K2 (9) is de-energized, being in the single-cylinder mode. The air intake and exhaust of the lower cylinder (2) are controlled by the on-off of the two-position five-way solenoid valve G2 (8), so as to make the piston ring (12) act to drive the piston rod (14) to act, thereby realizing the opening and closing of the valve; When P > P0, the two-position two-way normally closed solenoid valve K1 (7) is energized, and the two-position two-way normally open solenoid valve K2 (9) is energized, being in the double-cylinder mode. The air intake and exhaust of the upper cylinder (4) and the lower cylinder (2) are simultaneously controlled by the on-off of the two-position five-way solenoid valve G2 (8) and the two-position five-way solenoid valve G1 (6), so as to make the piston ring (12) act to drive the piston rod (14) to act, thereby realizing the opening and closing of the valve; c. After the operation of the high-temperature wind tunnel ends, the storage tank A (19) together with the supply pipeline (22) is depressurized, and the pneumatic globe valve B (23) returns to the single-cylinder mode again.

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