JP2002070648A - Hybrid rocket engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid rocket engine allowing effective cooling of a nozzle part, keeping respective parts below allowable temperature to prevent deterioration of materials, and allowing easy inspection and replacement to allow reuse. SOLUTION: This hybrid rocket engine has a liquid propellant tank 8 storing a liquid propellant 7, a solid motor case 10 storing a solid propellant 3, and a turbo pump 9 comprising a pump 9a and a turbine 9b. The solid motor case 10 has a double-cylinder structure with a refrigerant passage 11. The liquid propellant 7 is passed through the passage 11 to cool the motor case 10, vaporized or temperature-raised gas is supplied to the turbine 9b to rotationally drive the pump 9a, and a shape of the passage 11 is kept proper by the solid propellant 3. Thereby, the solid motor case 10 is reusable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solid motor case of a hybrid rocket engine using a liquid propellant and a solid propellant, and a cooling method thereof.

[0002]

2. Description of the Related Art Hybrid rocket engines using a liquid propellant and a solid propellant include those using a liquid fuel as a liquid propellant, a solid oxidant as a solid propellant, and those using a solid fuel and a liquid oxidant. There is. These hybrid rocket engines have high safety because the fuel and oxidant are separated, and have the features of combining the advantages of solid rockets (stability) with the advantages of liquid rockets (controllability). The development of a high rocket engine is currently in progress.

[0003] Hybrid rocket engines can be broadly classified into a gas pushing system and a pump system depending on the supply system of the liquid propellant. The gas-push type hybrid rocket engine is disclosed in, for example, Japanese Patent No. 2666883, Japanese Patent No. 2673663, Japanese Patent Laid-Open No.
No. 3,110,594 and 7,310,595. As a pump type hybrid rocket engine, Japanese Patent Application Laid-Open Nos. 8-93557 and 8-935 have been disclosed.
No. 58 is disclosed.

[0004]

FIG. 7 is a structural view showing an example of a conventional solid rocket engine. As shown in this figure, in the conventional solid rocket engine, the solid motor case 1 constituting the combustor is used without cooling, and the heat insulating material 2 (insulation liner, combustion inhibitor, etc.) reduces the temperature of the motor case 1. It was used below the allowable temperature of the material. Further, all the heat generated by the combustion gas is released to the outside and is not used. In this figure, 3 is a solid propellant, 4 is a nozzle, and 5 is a graphite throat.

When the conventional solid rocket engine shown in FIG. 7 is applied to the above-mentioned hybrid rocket engine, there are the following problems. (1) Since the nozzle portion 4 and the throat portion 5 are not cooled, it is necessary to use a heat-resistant material (for example, graphite or ceramics) and cannot be reused. (2) Since the solid propellant 3 is adhered to the inner surface of the solid motor case 1 through the heat insulating material 2 such as asbestos, it is more difficult to reuse the solid propellant 3. (3) If the combustion efficiency is improved, the thrust pattern is adjusted, etc., the durability of the portion where the combustion gas is in direct contact with the wall surface is reduced, and it cannot be reused. (4) Since different materials are used for the motor case, the heat insulating material, the nozzle portion, the throat portion, and the like, the production is difficult, and the inspection and replacement are difficult, so that they cannot be reused.

The present invention has been made to solve such a problem. In other words, an object of the present invention is to provide a hybrid that can effectively cool the nozzle portion, maintain each portion at or below an allowable temperature to prevent deterioration of the material, and can be easily inspected and replaced for reuse. To provide a rocket engine.

[0007]

According to the present invention, a liquid propellant tank (8) containing a liquid propellant (7), a solid motor case (10) containing a solid propellant (3),
A hybrid rocket engine including a pump (9a) and a turbo pump (9) including a turbine (9b), wherein the solid motor case (10) has a double cylinder structure having a coolant passage (11). A hybrid rocket engine characterized in that a liquid propellant is passed through the passage (11) to cool the motor case, and vaporized or heated gas is supplied to the turbine to rotate the pump. You.

According to the structure of the present invention, the liquid propellant (7)
The motor case is cooled by passing through the coolant passage (11), so that the motor case (10) can be effectively cooled, and an alloy having a relatively low heat-resistant temperature can be used.
In addition, durability and life can be extended and reuse can be made possible. Further, since the liquid propellant is used as the coolant, the turbo pump (9) can be efficiently driven using the heated gas as a power source.

According to a preferred embodiment of the present invention, the coolant passage (11) is configured to be parallel, perpendicular, or spiral with respect to an axis. With this configuration, by changing the direction of the cooling groove, cooling of the motor case can be performed in most combustion systems.

[0010] Further, it is preferable that the coolant passage (11) is formed so that the coolant passage is separated from the propellant at a portion along the solid propellant. With this configuration, by adjusting the thickness of the cooling groove and the inner wall, a portion requiring cooling and a portion not requiring much cooling can be appropriately cooled, and for example, the solid propellant is prevented from freezing at a low temperature by a coolant. be able to.

Further, a heat insulating material is provided outside the solid motor case (10). With this configuration, it is possible to prevent the temperature of the refrigerant from rising due to the outside air temperature.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the same reference numerals are given to the common parts in the respective drawings, and the duplicate description will be omitted.

FIG. 1 is an overall system diagram showing a first embodiment of a hybrid rocket engine according to the present invention. As shown in the figure, the hybrid rocket engine of the present invention has a liquid propellant tank 8 containing a liquid propellant 7.
A solid motor case 10 containing the solid propellant 3;
A turbo pump 9 including a pump 9a and a turbine 9b is provided.

As a liquid propellant, for example, liquefied hydrogen or LNG is used as a liquid fuel, and liquefied oxygen is used as a liquid oxidant. As the solid propellant, a propellant conventionally used in a solid rocket can be used. The pump 9a and the turbine 9b of the turbopump 9 are preferably connected by the same shaft as shown in FIG. Also,
They may be connected via a gear train instead of the same shaft. The solid motor case 10 is formed in a double cylinder structure having a coolant passage 11. The liquid propellant is supplied to the coolant passage 11.
To cool the motor case 10 and supply the vaporized or heated gas to the turbine 9b to rotate the pump 9a.

FIG. 2 is a view showing a first embodiment of the solid motor case of FIG. In this figure, (A) is an entire cross-sectional view of the solid motor case 10, (B) is an enlarged view of a portion A, and (C) is another configuration diagram of (B).

In FIG. 2A, 13a and 13b are coolant ports, and 12 is an injector. As shown in this figure, this embodiment is of the collision combustion type, in which a pair of hollow cylindrical solid propellants 3 are built in vertically spaced apart, and the collision combustion (pre-combustion) is performed in the gap. It is supposed to. In this case, the solid motor case 10 facing this gap
The inner surface is heated more than the other parts.

As shown in FIG. 2B, in this embodiment, in the portion where the solid propellant 3 is provided, the coolant passage 11 is configured to be separated from the propellant, and conversely, in the portion where the solid propellant 3 is not provided, the inner wall is provided. It is located near. That is, in this example, the coolant passage 11 is configured as a gap between the inner member 10a and the outer member 10b. In this case, the inner member 10a is preferably made of a material having high thermal conductivity, for example, copper or a copper alloy, and the outer member 10b is preferably made of a material having good pressure resistance, for example, Inconel material. With this configuration, a portion that requires cooling and a portion that does not require cooling can be appropriately cooled, and for example, the solid propellant can be prevented from freezing at a low temperature by a coolant.

In this embodiment, a heat insulating material 14 is provided outside the solid motor case 10 in order to prevent the temperature of the refrigerant from rising due to the outside air temperature.

FIG. 2C is another block diagram of FIG. 2B. That is, in this example, a spacer block 10c (for example, a Ti block) is interposed between the inner member 10a and the outer member 10b, and the coolant passage 11 is configured to be separated from the propellant in a portion where the solid propellant 3 exists, Conversely, the portion without the solid propellant 3 is located near the inner wall. With this configuration, the shape of the coolant passage 11 can be more easily changed.

FIG. 3 is a view showing a second embodiment of the solid motor case 10. 3A is an overall sectional view of the solid motor case 10, and FIG. 3B is an enlarged view of a portion A. In this example, the solid propellant is of the impingement type,
A pair of solid propellants 3 are built in at intervals vertically. However, in this example, the coolant passage 11 is arranged in a cylindrical shape so as to surround the upper and lower spaces of the pair of solid propellants 3,
This part that is easily overheated is actively cooled. Other configurations are the same as in the first embodiment.

FIG. 4 is a view showing a third embodiment of the solid motor case. In this example, the coolant passage 11 is configured to be parallel to the axis at the nozzle portion, and is configured to be helical to the axis at the main body portion containing the solid propellant. The solid propellant 3 of this example is of an end combustion type. With this configuration, cooling suitable for the nozzle portion and the main body portion can be performed.

FIG. 5 is a view showing a fourth embodiment of the solid motor case. In this figure, (A) is an overall side view of the solid motor case 10, (B) is a cross-sectional view taken along AA,
(C) is BB sectional drawing. The solid propellant 3 of this example is of an internal combustion type, and the coolant passage 11 is configured to be parallel to the axis at both the nozzle portion and the main body portion. FIG.
In the main body portion of FIG. 5B, the coolant passage 11 is arranged closer to the outer wall. In the nozzle portion of FIG. 5C, the coolant passage 11 is arranged closer to the inner wall. With this configuration,
The nozzle portion can be more actively cooled than the main body portion.

FIG. 6 is a view showing a fifth embodiment of the solid motor case. In this figure, (A) is an overall sectional view of the solid motor case 10, (B) is an AA sectional view,
(C) is BB sectional drawing. Solid propellant 3 in this example
Is an external combustion type, and the entire solid motor case 10 is exposed to a flame and is overheated. For this reason, in the motor case 10 of the present invention, the coolant passage 11 is configured to be parallel to the axis at both the nozzle portion and the main body portion, and is formed as shown in FIG.
In both the main body portion and the nozzle portion of FIG. 5C, the coolant passage 11 is disposed closer to the inner wall. With this configuration, both the nozzle portion and the main body portion can be actively cooled.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0025]

As described above, according to the structure of the present invention, the motor case is cooled through the coolant passage 11 of the liquid propellant 7, so that the motor case 10 can be cooled effectively. An alloy having a relatively low heat-resistant temperature can be used, and durability and life can be extended to enable reuse. Further, since the liquid propellant is used as the coolant, the turbo pump 9 can be efficiently driven using the pressurized gas as a power source.

Therefore, the hybrid rocket engine of the present invention can effectively cool the nozzle portion, and keep each portion below the allowable temperature to prevent deterioration of the material.
It has excellent effects such as easy inspection and replacement and reuse.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hybrid rocket engine of the present invention.

FIG. 2 is a view showing a first embodiment of the solid motor case of FIG. 1;

FIG. 3 is a view showing a second embodiment of the solid motor case.

FIG. 4 is a view showing a third embodiment of a solid motor case.

FIG. 5 is a view showing a fourth embodiment of the solid motor case.

FIG. 6 is a view showing a fifth embodiment of the solid motor case.

FIG. 7 is a structural view showing an example of a conventional solid rocket engine.

[Explanation of symbols]

1 solid motor case, 2 heat insulator, 3 solid propellant,
4 Nozzle part, 5 throat part, 7 liquid propellant, 8
Liquid propellant tank, 9 turbo pump, 9a pump,
9b Turbine, 10 solid motor case, 10a inner member, 10b outer member, 10c spacer block, 11 coolant passage, 12 injector, 13a, 13b
Coolant doorway

Claims (4)

[Claims] 1. A liquid propellant tank (8) containing a liquid propellant (7), a solid motor case (10) containing a solid propellant (3), a pump (9a) and a turbine (9).
b) a hybrid rocket engine comprising a turbo pump (9), wherein the solid motor case (10) has a coolant passage (11).
A double cylindrical structure having a liquid propellant in the passage (1).
1) A hybrid rocket engine, wherein the motor case is cooled through 1), and vaporized or heated gas is supplied to the turbine to rotate a pump. 2. The hybrid rocket engine according to claim 1, wherein the coolant passage (11) is configured to be parallel, perpendicular, or spiral with respect to an axis. 3. The hybrid rocket engine according to claim 1, wherein the coolant passage (11) is configured so that the coolant passage is separated from the propellant at a portion along the solid propellant. 4. The hybrid rocket engine according to claim 1, further comprising a heat insulating material outside the solid motor case (10).