JP2001124602A - Space navigating body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a space navigating body capable of suppressing damage to an apparatus due to temporary pressure wave developed in a pipe without increasing an installation cost. SOLUTION: In this space navigating body, a fluid in a propellant tank 10 is supplied to a jet tube 19 through a propellant pipe 12. The navigating body is equipped with a branch pipe 20 branching from the propellant pipe 12, an accessory apparatus 22 connected to the branch pipe 20. and a flow adjustment part 24 for limiting the hourly flow rate of the fluid flowing from the propellant pipe 12 into the branch pipe 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacecraft for supplying fluid in a propellant tank to a propulsion device via a propellant pipe in order to obtain a thrust in space.

[0002]

2. Description of the Related Art A spacecraft such as a satellite supplies fluid (propellant) in a tank (propellant tank) to a propulsion device such as a thruster through a pipe (propellant pipe) when moving in space. Thrust may be obtained from the thruster. FIG. 6 shows a propulsion system (propellant propulsion system) in such a conventional space vehicle.
The symbol 1 indicates a propellant tank, the symbol 2 indicates a propellant pipe, and the symbol 3 indicates a propulsion device. The propellant propulsion system is provided with a branch pipe 4 branching from the propellant pipe 2, and an auxiliary device 5 having a pressure gauge and the like is provided at the end of the branch pipe 4.

In the propellant propulsion system, on the ground, a shutoff valve 6 and a propellant valve 7 are closed to prevent the propellant from leaking outside, and the propellant is supplied to the propellant pipe 2 and the branch pipe 4. It is in a state without intervention. After the launch, in the propellant propulsion system, when operating the propellant propulsion system in outer space, first, the shutoff valve 6 is opened to fill the propellant pipe 2 with the propellant (priming). The propellant is supplied to the propulsion device 3 by opening.

[0004]

However, in such a conventional spacecraft, when the shut-off valve 6 is opened, the propellant flows out of the propellant tank 1 into the propellant pipe 2 at a stretch. A temporary pressure wave is generated inside the propellant pipe 2 by colliding with the propellant valve 7, and an excessive surge pressure at this time is generated in the branch pipe 4 via the propellant by the auxiliary equipment 5.
And the incidental device 5 may be damaged.
In particular, a measuring device such as a pressure gauge is often formed with a small pressure receiving area of a detecting portion that comes into contact with a fluid for the purpose of high-accuracy measurement, and thus is easily damaged by a sudden pressure fluctuation. Further, if the auxiliary equipment is configured to have a high pressure resistance so as to withstand a surge pressure, there is a problem that the fluid cannot be measured with sufficient accuracy, and the equipment cost increases.

[0005] The present invention has been made in view of the above circumstances, and without greatly increasing equipment costs.
An object of the present invention is to provide a spacecraft capable of suppressing damage to equipment due to temporary pressure waves generated in piping.

[0006]

The invention according to claim 1 is
In a spacecraft that supplies the fluid in the propellant tank to the propulsion device via propellant piping to obtain thrust in outer space,
Adopts a technology that includes a branch pipe that branches from the propellant pipe, ancillary equipment connected to the branch pipe, and a flow rate adjustment unit that limits the flow rate per hour of the fluid flowing from the propellant pipe into the branch pipe. Is done. According to a second aspect of the present invention, in the space vehicle of the first aspect, a technique is employed in which the flow rate adjusting portion has a flow path formed with a predetermined cross-sectional area smaller than the flow path cross-sectional area of the branch pipe. . The invention according to claim 3 is
In the space vehicle according to the second aspect, a technique is adopted in which the cross-sectional area of the flow path of the flow rate adjusting unit is determined according to the internal volume of the branch pipe. In this spacecraft, since the flow rate per hour of the fluid flowing from the propellant pipe to the branch pipe is limited by the flow rate adjustment unit, it takes time until the fluid flowing from the propellant pipe is filled in the branch pipe. . Therefore, even if a temporary pressure wave occurs in the propellant pipe when the fluid is filled in the propellant pipe, the pressure wave attenuates until the fluid is filled in the branch pipe. Is difficult to propagate. Therefore, the problem described above can be solved by employing the technique of the present invention.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a spacecraft according to the present invention will be described below with reference to the drawings. FIG.
2 shows a propulsion system S in the space vehicle of the present embodiment. The propulsion system S is a propellant propulsion system that uses two types of liquids (propellants), and has two propellant tanks 10 and 11 for storing propellants. An oxidizing agent such as liquid oxygen is stored in the propellant tank 10, and a fuel such as liquid fluorine is stored in the propellant tank 11.

The propellant tanks 10 and 11 are connected to propellant pipes 12 and 13, respectively, and are configured to discharge the propellant to the propellant pipes 12 and 13 when the shutoff valves 14 and 15 are opened. Reference numeral 16 denotes a pressurized tank filled with a pressurized gas such as helium gas, for increasing the pressure in the propellant tanks 10 and 11 when discharging the propellant.

One end of the propellant pipes 12 and 13 is connected to a propulsion device 19 such as a thruster via propellant valves 17 and 18. The propellant valves 17 and 18 are connected to a propulsion device 19.
The purpose is to adjust the flow rate of the propellant supplied to the apparatus.
The propulsion device 19 is configured to generate a thrust in outer space by being supplied with a propellant.

In the propellant propulsion system S, the propellant pipe 1
Branch pipes 20 and 21 are provided branching from 2 and 13, and the branch pipes 20 and 21 are connected to auxiliary devices 22 and 23. The auxiliary equipments 22 and 23 are connected to the branch pipe 2
It is for examining the properties and state of the propellant using the propellant charged in 0 and 21, and has a measuring device such as a pressure gauge.

FIG. 3 shows a flow control section 24 provided at a joint between the propellant pipe 12 (or the propellant pipe 13) and the branch pipe 20 (or the branch pipe 21). The flow rate adjusting unit 24 of the present embodiment is configured such that a through-hole (orifice: for example, the inner diameter is smaller) is formed so as to form a flow path having a smaller cross-sectional area than the flow path cross-sectional area of the branch pipe 20 (e.g. (0.5 mm) A cylindrical member having 24a is fitted in the branch pipe 20. Flow control unit 24
Then, a part of the propellant in the propellant pipe 12
The flow rate of the propellant flowing from the propellant pipe 12 to the branch pipe 20 per hour is restricted by flowing to the branch pipe 20 through the branch pipe 20.

A spacecraft equipped with such a propellant propulsion system S is launched into outer space and then, to obtain thrust,
The propellant in the propellant tanks 10 and 11 is supplied to the propulsion device 19 via the propellant pipes 12 and 13. Hereinafter, the propellant is the propulsion device 1
The process up to supply to 9 will be described with reference to FIGS. In addition, although this embodiment has two propellant tanks 10 and 11 as mentioned above, here, the propellant tank 10 side will be described.

First, on the ground, as shown in FIG. 1A, the shutoff valve 14 and the propellant valve 17 are closed to prevent the propellant from leaking from the propulsion device 19 side to the outside. The medicine pipe 12 is filled with a gas such as helium gas or nitrogen gas. The pressure in the propellant pipe 12 at this time is, for example, about 0.5 kg / cm ² .

After the launch, when the operation of the propellant propulsion system S is started in the outer space, first, the shielding valve 14 is opened, and the propellant is filled in the propellant pipe 12 (priming). The internal pressure of the propellant tank 10 at this time is, for example, about 1
0 kg / cm ^2, which is set higher than the pressure in the propellant pipe 12. Therefore, as shown in FIG. 1B, the propellant flows out of the propellant tank 10 at a stretch into the propellant pipe 12 due to the pressure difference, and the propellant is filled in the propellant pipe 12.
Then, as shown in FIG.
A pressure wave is generated inside the propellant pipe 12 due to an impact when it collides with the inner wall of the propellant pipe 7 or 7.

FIG. 4 shows the surge pressure in the propellant pipe 12 due to the pressure wave. The pressure wave has the highest energy at the beginning of the generation, then rapidly decays, and completely decays after a predetermined time Tp (several seconds). The pressure wave propagates through the propellant, and the propellant valve 17 and the propellant pipe 12 shown in FIG.
Acts as a surge pressure on the inner wall of the vehicle. In addition, while the inside of the pipe is not filled with the propellant, the pressure wave hardly propagates, and the surge pressure hardly acts. Further, the propellant valve 17 and the propellant pipe 12 have sufficient rigidity to withstand a temporary surge pressure.

At this time, a part of the propellant in the propellant pipe 12 passes through the orifice 24a of the flow rate adjusting unit 24 and is connected to the branch pipe 20.
Flow into the interior. Since the orifice 24a has a smaller flow path cross-sectional area than the branch pipe 20, the propellant pipe 1
The flow rate per unit time of the propellant flowing from 2 to the branch pipe 20 is limited by the flow rate adjusting unit 24, and it takes some time until the branch pipe 20 is filled with the propellant. Therefore, the pressure wave generated in the propellant pipe 12 is attenuated in the propellant pipe 12 before the branch pipe 20 is filled with the propellant, and
It is hardly propagated to zero.

After the branch pipe 20 is filled with the propellant, the propellant valve 17 is opened and the propellant is supplied to the propulsion device 19 as shown in FIG. Thereby, it is possible to obtain the thrust by the propulsion device 19.

As described above, according to the present embodiment, the flow rate per hour of the propellant flowing from the propellant pipe 12 to the branch pipe 20 is restricted by the flow rate adjusting unit 24, so that the propellant is temporarily stored in the propellant pipe 12. Pressure wave is generated, the pressure wave
2 and is hardly propagated in the branch pipe 20. Therefore, the pressure surge hardly acts on the incidental device 22 connected to the branch pipe 20, and damage to the incidental device 22 can be suppressed.

Here, the orifice 24 of the flow rate adjusting unit 24
A method for determining the flow path cross-sectional area of a will be described. In the present embodiment, the flow path cross-sectional area of the orifice 24 a is determined according to the internal volume of the branch pipe 20. That is, the time Tp from when the pressure wave is generated in the propellant pipe 12 to when the pressure wave is attenuated.
Is obtained by analysis or experiment, and this time Tp
The flow path cross-sectional area of the orifice 24a is determined so that the total flow rate of the propellant passing through the orifice 24a does not reach the internal volume of the branch pipe 20. Thereby, the pressure wave is completely attenuated in the propellant pipe 12 before the propellant is filled in the branch pipe 20, and the damage to the incidental device 22 can be surely suppressed.

Although the propellant tank 10 has been described so far, the propellant tank 11 can also be used in the same manner as described above to prevent the incidental device 23 from being damaged. Further, the shapes, combinations, and the like of the respective constituent members shown in the above-described embodiments are merely examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

FIG. 5 shows another embodiment of the present invention. In the embodiment shown in FIG. 5, an adjustment member 31 is provided in the flow path adjustment unit 30, and by changing the arrangement position of the adjustment member 31, the flow path cross-sectional area of the orifice 30a can be changed. It has a configuration. Thus, according to this embodiment, the orifice 30
The flow path cross-sectional area of “a” can be appropriately adjusted, and the damage to the incidental device 32 can be reliably suppressed according to various use conditions.

[0022]

As described above, according to the present invention, the following effects can be obtained. In the spacecraft according to claim 1, the flow rate per unit time of the fluid flowing from the propellant pipe to the branch pipe is limited by the flow rate adjustment unit, and the time required for the fluid flowing from the propellant pipe to be filled in the branch pipe. Therefore, even if a temporary pressure wave is generated in the propellant pipe, the pressure wave is not easily transmitted to the auxiliary equipment. Therefore, it is possible to suppress the damage to the incidental device due to the temporary pressure wave generated in the propellant pipe. Further, since it is not necessary to make the auxiliary equipment have a configuration with an excessively high pressure resistance, the equipment cost can be suppressed.

In the spacecraft according to the second aspect, since the flow path is formed with a predetermined cross-sectional area smaller than the flow path cross-sectional area of the branch pipe, the time required for the fluid flowing from the propellant pipe into the branch pipe to be increased. Can be easily limited.

In the space vehicle according to the third aspect, since the cross-sectional area of the flow path of the flow rate adjusting unit is determined according to the internal volume of the branch pipe, the propellant pipe is not filled until the distribution pipe is filled with fluid. It is possible to completely attenuate the internal pressure wave, and it is possible to more reliably suppress damage to the incidental devices.

[Brief description of the drawings]

FIG. 1 is a view for explaining a state of a flow of a propellant in an embodiment of a spacecraft according to the present invention.

FIG. 2 is a configuration diagram showing a propulsion system of the embodiment of FIG.

FIG. 3 is a cross-sectional view showing a flow rate adjusting unit of the embodiment of FIG.

FIG. 4 is a waveform diagram showing a surge pressure due to a pressure wave.

FIG. 5 is a cross-sectional view showing another embodiment of the present invention.

FIG. 6 is a diagram for explaining a conventional space vehicle.

[Explanation of symbols]

 10, 11 Propellant tank 12, 13 Propellant pipe 14, 15 Shutoff valve 17, 18 Propellant valve 19 Propulsion machine 20, 21 Branch pipe 22, 23 Auxiliary equipment 24 Flow rate adjustment unit 24a Orifice

Claims (3)

[Claims] 1. A spacecraft for supplying a fluid in a propellant tank to a propulsion device via a propellant pipe in order to obtain a thrust in outer space, comprising: a branch pipe branching off from the propellant pipe; A spacecraft, comprising: ancillary equipment connected to the branch pipe; and a flow rate adjusting unit that limits a flow rate per hour of a fluid flowing from the propellant pipe into the branch pipe. 2. The spacecraft according to claim 1, wherein a flow path having a predetermined cross-sectional area smaller than a flow path cross-sectional area of the branch pipe is formed in the flow rate adjusting unit. 3. The spacecraft according to claim 2, wherein a cross-sectional area of the flow path is determined according to an internal volume of the branch pipe.