Water hammer effect protection system and method in carrier rocket filling process

Abstract

The invention discloses a water hammer effect protection system and method in the filling process of a carrier rocket. The protection system comprises a liquid storage tank, an engine storage tank, a main pipeline, a shunting pipeline and a backflow pipeline, the main pipeline is used for conveying a propellant from the liquid storage tank to the engine storage tank, and a storage tank liquid outlet valve, a variable frequency pump, a regulating valve DT1, a pressure sensor, a pipeline control ball valve, a first-stage filling pipeline control ball valve and a second-stage filling pipeline control ball valve are sequentially arranged on the main pipeline; the backflow pipeline is used for conveying unused propellants back into the liquid storage tank and is provided with a backflow ball valve and a storage tank liquid inlet valve, and the storage tank liquid inlet valve is connected with the liquid storage tank; a DT2 and a shunting pipeline ball valve are sequentially arranged on the shunting pipeline, and the shunting pipeline ball valve is connected with the storage tank liquid inlet valve. Major potential safety hazards such as pipeline leakage and even explosion caused by the water hammer effect are avoided, the service life of the pipeline and the ball valve is prolonged, the maintenance cost is reduced, and the reliability of a propellant filling system is improved.

Description

Technical Field

[0001] The present invention relates to the field of preventing failures of ground equipment at a launch site, and particularly to a protection system and method for water hammer effect during the propellant filling process of a launch vehicle. Background Art

[0002] The basic task of the propellant filling system is to fill the propellant into the rocket tank "safely, reliably, precisely, and quickly". The basic working principle is to transfer the propellant in the storage tank in the warehouse to the rocket tank through the filling fixed pipeline and filling hose by means of pressurization, extrusion or self-flow of the filling pump. For current rockets, they can be divided into two-stage or three-stage rockets. Taking a two-stage rocket as an example below, after the filling of the first-stage tank of the rocket is completed, how to switch from the first-stage filling state to the second-stage filling state without stopping the pump, so as to complete the filling task safely and quickly within the specified time is crucial for ensuring the successful launch of the rocket.

[0003] After the first-stage filling is completed, the propellant is in a state of flowing back to the warehouse before the second-stage filling starts. When the filling state is switched to the second stage, the second-stage filling pipeline is communicated. Since some propellants have filled the filling pipeline from the warehouse to the tower, at the moment when the upper tower valve is opened, the propellant in the pipeline will generate a water hammer effect with the pipeline and equipment in the warehouse. If not controlled properly, it will cause pipeline vibration and flow rate change in the lightest case; in the severest case, it will lead to pipeline bursting, causing significant economic losses and accident injuries. The so-called water hammer phenomenon refers to the phenomenon that during the filling process, when the fluid in the pressure pipeline undergoes a sharp change in flow velocity due to certain reasons, due to the inertia of the fluid, a rapid alternation of the internal pressure of the fluid occurs, and this alternately rising and falling pressure acts on the pipe wall, valve or other pipeline components like hammer blows.

[0004] In systems related to the water hammer effect, the prevention of the water hammer effect mainly includes: one is the water hammer caused by opening and closing the valve too quickly, which can be prevented by extending the time for opening and closing the valve; the other is the water hammer caused by the pump. For normal start and stop of the pump and emergency stop of the pump, the air in the pipeline can be removed, and the pump can be started after the pipeline is filled with water. In addition, it may also be caused by the too-fast closing of the check valve in the outlet pipe. Therefore, canceling the check valve can eliminate the water hammer caused by pump stop.

[0005] During the process of filling the propellant of a launch vehicle from the first stage to the second stage or further to the third stage, there will be changes in the operating conditions of the pump and valve switching in the pipeline. Therefore, when designing the propellant filling of a launch vehicle, water hammer analysis, prediction and simulation of the occurrence and propagation law of water hammer under accident conditions should be carried out in advance. How to design the opening time and sequence of each valve in the warehouse pipeline during this process, so as to avoid the water hammer effect, is of great significance for the filling process and even the successful launch of the launch vehicle. This is the key to optimizing the engineering design, reducing the project cost and ensuring the safe operation of the system, and has important theoretical significance and practical value. Summary of the Invention

[0006] In view of the technical defects in dealing with the water hammer effect during the fueling process of existing launch vehicles, the present invention provides a water hammer effect protection system and method for the fueling process of launch vehicles. During the stage conversion of the launch vehicle fueling, the water hammer effect generated by the propellant filled in the tower pipeline on the pipeline in the storage warehouse is controlled by adjusting the opening and closing times of several key pneumatic ball valves and the opening degree of the electric control valve in the pipeline in the storage warehouse. By shunting and boosting the pipeline, the pressure on one side of the main pipeline is not lower than the pressure on the side of the return pipeline, so as to successfully complete the stage conversion process of the launch vehicle propellant fueling, avoid the occurrence of the water hammer effect, and ensure the safety of the launch vehicle propellant fueling. The specific technical solutions are as follows:

[0007] A water hammer effect protection system for the fueling process of a launch vehicle, the protection system includes a liquid storage tank, an engine storage tank, a main pipeline, a shunt pipeline, and a return pipeline, where:

[0008] The engine storage tank includes a first-stage storage tank and a second-stage storage tank;

[0009] The main pipeline is used to transport the propellant from the liquid storage tank to the engine storage tank, and is sequentially provided with a storage tank liquid outlet valve, a variable frequency pump, a control valve DT1, a pressure sensor, a pipeline control ball valve, a first-stage fueling pipeline control ball valve, and a second-stage fueling pipeline control ball valve;

[0010] The pressure sensor is used to measure the pressure in the pipeline;

[0011] The pipeline control ball valve is an anti-hammer effect valve, and the filling of the liquid propellant is realized by the opening and closing of this valve;

[0012] The first-stage fueling pipeline control ball valve is connected to the first-stage storage tank, and the first-stage fueling pipeline control ball valve is used to control the opening and closing of the propellant in the first-stage storage tank;

[0013] The second-stage fueling pipeline control ball valve is connected to the second-stage storage tank and is used to control the opening and closing of the propellant in the second-stage storage tank;

[0014] The return pipeline is used to send the unused propellant back to the liquid storage tank, and is sequentially provided with a return ball valve and a storage tank liquid inlet valve, and the storage tank liquid inlet valve is connected to the liquid storage tank;

[0015] The return ball valve is used to keep the variable frequency pump running without stopping during stage conversion and keep the propellant liquid in a flowing state;

[0016] The shunt pipeline is sequentially provided with a control valve DT2 and a shunt pipeline ball valve, and the shunt pipeline ball valve is connected to the storage tank liquid inlet valve;

[0017] Furthermore, the control valve DT1 and the control valve DT2 are electric control valves, and the flow rate of the liquid propellant is adjusted by adjusting the opening degree;

[0018] Further, the variable-frequency pump, regulating valve DT1, and regulating valve DT2 are all driven by motors;

[0019] Further, the rotation speed of the canned motor pump, the opening degree of the electric regulating valve, and the opening and closing of the pneumatic ball valve are all controlled by the PLC system.

[0020] The present invention also discloses a method for using the above-mentioned water hammer effect protection system during the fueling process of a launch vehicle, which includes the following steps:

[0021] S1. After the first stage of the launch vehicle is fueled, it is the stage of the first and second stage state conversion. At this time, the propellant is in the state of pumping back, the shunt pipeline ball valve is in the closed state, and the warehouse return ball valve is in the open state;

[0022] S2. After the second stage fueling starts, delay for 60 s, and the regulating valve DT2 automatically adjusts the opening degree to 80%, and opens the shunt pipeline ball valve to ensure that there will be no pump cavitation phenomenon after the warehouse return ball valve is closed subsequently;

[0023] S3. After a delay of 20 s, the warehouse return ball valve is automatically closed. At this time, the variable-frequency pump keeps running, the return pipeline through the warehouse return ball valve is closed, the shunt pipeline through the shunt pipeline ball valve is opened, the flow resistance of the liquid behind the pump increases, and the pressure sensor on the main pipeline continuously increases.

[0024] Further, the return main pipeline is a pipeline with a diameter of DN100, and the shunt pipeline is a pipeline with a diameter of DN50;

[0025] S4. After a delay of 15 s, when the pressure detected by the pressure sensor at the propellant upper tower gradually rises to be equal to the pressure generated by the propellant in the return pipeline on the pipeline, the pipeline control ball valve is opened. Since the pressure before and after the pipeline control ball valve is basically balanced, the water hammer effect caused by the valve opening process is effectively protected;

[0026] 5) After a delay of 2 s, the shunt pipeline ball valve is closed, and the opening degree of the regulating valve DT2 is adjusted to 30%, and the shunt pipeline is closed, and the process ends, and the second stage fueling is carried out according to the normal process;

[0027] 6) All subsequent inter-stage conversions are operated according to steps 1) to 5) to achieve the protection of the water hammer effect.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] After the implementation of the protection method provided by the present invention and through multiple experimental verifications and actual mission executions, the average pressure detected by the pressure sensor is 1.4 MPa, which is close to the normal operating pressure of 1.2 MPa and far lower than 1.2 MPa when the water hammer protection system is not adopted. There are no noises or leakage phenomena in on-site pipelines, ball valves and other equipment, avoiding major safety hazards such as pipeline leakage and even explosion caused by the water hammer effect, thus extending the service life of the propellant pipeline and ball valve, reducing the maintenance cost, and improving the reliability of the propellant filling system. Brief Description of the Drawings

[0030] Figure 1 It is a schematic diagram of a water hammer effect protection system for a launch vehicle filling process provided by the present invention.

[0031] Description of the Reference Numerals in the Drawings:

[0032] 1. Liquid outlet valve of the storage tank; 2. Liquid inlet valve of the storage tank; 3. Ball valve of the shunt pipeline; 4. Ball valve of the warehouse return pipeline; 5. Pipeline control ball valve; 6. First-stage filling pipeline control ball valve; 7. Second-stage filling pipeline control ball valve; 8. Liquid storage tank; 9. First-stage storage tank; Variable frequency pump; 10. Second-stage storage tank; 12. Pressure sensor. Detailed Embodiment

[0033] The present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] As Figure 1 shown, a water hammer effect protection system for a launch vehicle filling process, the protection system includes a liquid storage tank 8, an engine storage tank, a main pipeline, a shunt pipeline, and a return pipeline, wherein:

[0035] The engine storage tank includes a first-stage storage tank 9 and a second-stage storage tank 10;

[0036] The main pipeline is used to transport the propellant from the liquid storage tank 8 to the engine storage tank, and is sequentially provided with a liquid outlet valve 1 of the storage tank, a variable frequency pump 11, a regulating valve DT1, a pressure sensor (P1) 12, a pipeline control ball valve 5, a first-stage filling pipeline control ball valve 6, and a second-stage filling pipeline control ball valve 7;

[0037] The pressure sensor 12 is used to display the pressure in the pipeline;

[0038] The pipeline control ball valve 5 is an anti-hammer effect valve, and the filling of the liquid propellant is realized through the opening and closing of this valve;

[0039] The first-stage filling pipeline control ball valve 6 is connected to the first-stage storage tank 9, and the first-stage filling pipeline control ball valve 6 is used to control the opening and closing of the propellant in the first-stage storage tank;

[0040] The secondary filling pipeline control ball valve 7 is connected to the secondary storage tank 10 and is used to control the opening and closing of the propellant in the secondary storage tank;

[0041] The return pipeline is used to send the unused propellant back into the liquid storage tank 8, and is successively provided with a return ball valve 4 and a storage tank inlet valve 2, and the storage tank inlet valve 2 is connected to the liquid storage tank 8;

[0042] The return ball valve 4 is used to keep the variable frequency pump 11 running during stage conversion and maintain the propellant liquid in a flowing state;

[0043] The shunt pipeline is successively provided with a regulating valve DT2 and a shunt pipeline ball valve 3, and the shunt pipeline ball valve 3 is connected to the storage tank inlet valve 2;

[0044] Further, the regulating valve DT1 and the regulating valve DT2 are electric regulating valves, and the flow rate of the liquid propellant is adjusted by adjusting the opening degree;

[0045] Further, the variable frequency pump 1 and the regulating valves DT1 and DT2 are driven by a motor;

[0046] Further, the rotation speed of the canned motor pump, the opening degree of the electric regulating valve, and the opening and closing of the pneumatic ball valve are all controlled by the PLC system.

[0047] A method for protecting against water hammer effect during the filling process of a launch vehicle. In this embodiment, the return main pipeline uses a pipeline with a diameter of DN100, and the shunt pipeline uses a pipeline with a diameter of DN50. The specific steps are as follows:

[0048] S1. After the first-stage filling of the launch vehicle is completed, it is the stage of the first- and second-stage state conversion. At this time, the propellant is in the state of pumping back. At this time, the first-stage filling pipeline control ball valve 6 is closed, the shunt pipeline ball valve 3 is closed, and the warehouse return ball valve 4 is opened;

[0049] S2. After waiting for the start of secondary filling, delay for 60 s, and the regulating valve DT2 automatically adjusts the opening degree of the electric regulating valve to 80%, and opens the shunt pipeline ball valve 3 to ensure that there will be no pump choking phenomenon after the warehouse return ball valve 4 is closed subsequently;

[0050] S3. After a delay of 20 s, the warehouse return ball valve 4 is automatically closed. At this time, the variable frequency pump 11 keeps running. The return pipeline through the warehouse return ball valve 4 is closed, and the shunt pipeline through the shunt pipeline ball valve 3 is opened. The liquid flow resistance after the variable frequency pump increases, and the main pipeline pressure sensor 12 continuously increases.

[0051] S4. Delay for 15 s. When the pressure detected by the pressure sensor 12 at the propellant upper tower gradually rises to be equal to the pressure generated by the propellant in the tower return pipeline in the pipeline, open the pipeline control ball valve 5. Since the pressure before and after the pipeline control ball valve 5 is basically balanced, the water hammer effect caused by the valve opening process is effectively protected;

[0052] 7) Delay for 2 s, close the shunt pipeline ball valve 3, and adjust the opening of the regulating valve DT2 electric regulating valve to 30%, close the shunt pipe, and the process ends. Perform the second-stage filling according to the normal process;

[0053] 8) All subsequent inter-stage conversions can be operated according to the above method to achieve the protection of the water hammer effect.

[0054] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present invention.

Claims

1. A protection system for water hammer effect during the fueling process of a launch vehicle, characterized in that, The described protection system includes a liquid storage tank 8, an engine storage tank, a main pipeline, a shunt pipeline, and a return pipeline, where: The engine storage tank includes a first-stage storage tank and a second-stage storage tank; The main pipeline is used to transport the propellant from the liquid storage tank to the engine storage tank, and is sequentially provided with a storage tank liquid outlet valve, a variable-frequency pump, a regulating valve DT1, a pressure sensor, a pipeline control ball valve, a first-stage filling pipeline control ball valve, and a second-stage filling pipeline control ball valve; The pressure sensor is used to display the pressure magnitude in the pipeline; The pipeline control ball valve is a water hammer effect prevention valve, and the filling of the liquid propellant is realized through the opening and closing of this valve; The first-stage filling pipeline control ball valve is connected to the first-stage storage tank, and the first-stage filling pipeline control ball valve is used to control the opening and closing of the propellant in the first-stage storage tank; The second-stage filling pipeline control ball valve is connected to the second-stage storage tank and is used to control the opening and closing of the propellant in the second-stage storage tank; The return pipeline is used to send the unused propellant back to the liquid storage tank, and is sequentially provided with a return ball valve and a storage tank liquid inlet valve, and the storage tank liquid inlet valve is connected to the liquid storage tank; The return ball valve is used to keep the variable-frequency pump running during stage conversion and maintain the propellant liquid in a flowing state; The shunt pipeline is sequentially provided with a regulating valve DT2 and a shunt pipeline ball valve, and the shunt pipeline ball valve is connected to the storage tank liquid inlet valve.

2. The water hammer effect protection system for the fueling process of a launch vehicle according to claim 1, wherein The regulating valves DT1 and DT2 are electric regulating valves, and the flow rate of the liquid propellant is adjusted by adjusting the opening degree.

3. The water hammer effect protection system for the fueling process of a launch vehicle according to claim 1, characterized in that, The variable-frequency pump, the regulating valve DT1, and the regulating valve DT2 are all driven by motors.

4. The water hammer effect protection system for the fueling process of a launch vehicle according to claim 1, characterized in that, The rotation speed of the canned motor pump, the opening degree of the electric regulating valve, and the opening and closing of the pneumatic ball valve are all controlled by the PLC system.

5. The water hammer effect protection system for the fueling process of a launch vehicle according to claim 1, characterized in that The return main pipeline is a pipeline with a diameter of DN100, and the shunt pipeline is a pipeline with a diameter of DN50.

6. The water hammer effect protection system for the fueling process of a launch vehicle according to claim 1, wherein The pipeline control ball valve, the first-stage filling pipeline control ball valve, and the second-stage filling pipeline control ball valve are driven by two-position five-way solenoid valves.

7. A method of using the water hammer effect protection system for the fueling process of a launch vehicle according to any one of claims 1 to 6, characterized in that, It includes the following steps: S1. After the first-stage filling of the launch vehicle is completed, it is the stage of the first- and second-stage state conversion. At this time, the propellant is in a return state, the shunt pipeline ball valve is closed, and the warehouse return ball valve is opened; S2. After the start of the second-stage filling, delay for 60 s, and the regulating valve DT2 automatically adjusts the opening degree to 80%, and opens the shunt pipeline ball valve to ensure that there will be no pump cavitation phenomenon after the subsequent closing of the warehouse return ball valve; S3. After a delay of 20 s, automatically close the warehouse return ball valve. At this time, the variable-frequency pump keeps running, the return pipeline through the warehouse return ball valve is closed, the shunt pipeline through the shunt pipeline ball valve is opened, the liquid flow resistance after the variable-frequency pump increases, and the pressure of the pressure sensor in the main pipeline continues to increase; S4. Delay for 15 s. When the pressure at the propellant upper tower detected by the pressure sensor gradually rises to be equal to the pressure generated by the propellant in the tower pipeline on the warehouse, open the pipeline control ball valve. Since the pressure before and after the pipeline control ball valve is basically balanced, the water hammer effect caused by the valve opening process is effectively protected; S5. Delay for 2 s, close the shunt pipeline ball valve, and adjust the opening degree of the regulating valve DT2 to 30%, close the shunt pipeline, and the process ends, and the second-stage filling is carried out according to the normal process; S6. All subsequent stage conversions are operated according to steps 1) to 5) to achieve the protection of the water hammer effect.

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