阅读说明：本技术 一种多级泵级间分流的核热发动机系统 (Nuclear heat engine system with multistage pump interstage shunting ) 是由 王浩泽 徐凯 何雪晴 赵海龙 胡长喜 于槟恺 于 2020-04-07 设计创作，主要内容包括：一种多级泵级间分流的核热发动机系统,包括贮箱、多级泵、涡轮、轴系、主阀、副控阀、反应堆和推力室。本发明采用级间分流的方式,即部分工质从多级泵的非最末级叶轮2a输出端流出,另一部分工质从多级泵的最末级叶轮2b输出端流出。且从侧反射层7c出来的工质和从辅助加热元件7b出来的工质在集合腔7d入口处的压力几乎相等,两路工质压差的绝对值≤0.8MPa。本发明解决了现有核热火箭发动机闭式膨胀循环方案中涡轮泵轴功浪费的问题,实现了涡轮泵分系统轴功的降低,提高了核热火箭发动机的室压和比冲,并填补了国内低轴功核热火箭发动机闭式膨胀循环系统方案的空白。(A nuclear heat engine system with multi-stage pump interstage shunting comprises a storage tank, a multi-stage pump, a turbine, a shaft system, a main valve, a secondary control valve, a reactor and a thrust chamber. The invention adopts an interstage flow dividing mode, namely part of working medium flows out from the output end of the non-final-stage impeller 2a of the multi-stage pump, and the other part of working medium flows out from the output end of the final-stage impeller 2b of the multi-stage pump. And the pressure of the working medium from the side reflecting layer 7c and the pressure of the working medium from the auxiliary heating element 7b at the inlet of the collecting cavity 7d are almost equal, and the absolute value of the pressure difference of the two working mediums is less than or equal to 0.8 MPa. The invention solves the problem of shaft work waste of the turbopump in the closed expansion circulation scheme of the conventional nuclear thermal rocket engine, realizes the reduction of the shaft work of the turbopump subsystem, improves the room pressure and the specific impulse of the nuclear thermal rocket engine, and fills the blank of the domestic closed expansion circulation scheme of the low-shaft-work nuclear thermal rocket engine.)

1. A nuclear heat engine system with multistage pump interstage porting, characterized by: comprises a storage tank (1), a multi-stage pump (2), a turbine (3), a shaft system (4), a main valve (5), an auxiliary control valve (6), a reactor (7) and a thrust chamber (8); the reactor (7) is of a cylindrical structure, the innermost layer is a fuel element (7a), the outer side of the fuel element (7a) is coated with an auxiliary heating element (7b), the outer side of the auxiliary heating element (7b) is coated with a side reflecting layer (7c), and a collection cavity (7d) is arranged above the fuel element (7a) and the auxiliary heating element (7 b); a plurality of holes are arranged inside the fuel element (7a) and the auxiliary heating element (7 b); the thrust chamber (8) comprises a spray pipe (8a) and a regenerative cooling jacket (8b), wherein the regenerative cooling jacket (8b) is positioned outside the spray pipe (8 a); working medium channels communicated with each other are processed in the regenerative cooling jacket (8b) and the side reflecting layer (7c), and working medium inlet channels and working medium outlet channels communicated with each other are processed in the auxiliary heating element (7 b);

the multistage pump (2) is formed by connecting multistage impellers in series; the multistage pump (2) is connected with the turbine (3) through a shaft system (4), and the three components form a turbine pump subsystem; the outlet of the storage tank (1) is connected with the input end of a first-stage impeller of the multi-stage pump (2) through a pipeline, the output end of a non-last-stage impeller (2a) in the multi-stage pump (2) is connected with a main valve (5) through a pipeline, and the main valve (5) is connected with a working medium channel in a regenerative cooling jacket (8b) through a pipeline; the working medium channel outlet in the side reflecting layer (7c) is connected with the collecting cavity (7d) through a pipeline; the output end of the last-stage impeller (2b) of the multi-stage pump (2) is connected with an auxiliary control valve (6) through a pipeline, the auxiliary control valve (6) is connected with a working medium inlet channel in an auxiliary heating element (7b) through a pipeline, the outlet of a working medium outlet channel in the auxiliary heating element (7b) is connected with the inlet of a turbine (3) through a pipeline, and the outlet of the turbine (3) is connected with a collection cavity (7d) through a pipeline; the main valve (5), the secondary control valve (6) and the reactor (7) are all connected with an external control system.

2. The nuclear heat engine system with multistage pump interstage flow splitting according to claim 1, wherein: the absolute value of the pressure difference between the gas working medium entering the inlet of the collecting cavity (7d) through the working medium channel of the side reflecting layer (7c) and the gas working medium entering the inlet of the collecting cavity (7d) from the outlet of the turbine (3) is less than or equal to 0.8 MPa.

3. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: the output end of the non-final-stage impeller (2a) and the output end of the final-stage impeller (2b) are both provided with adjusting elements for adjusting the mass flow of the flowing working medium.

4. A multi-stage pump interstage split nuclear heat engine system according to claim 3, wherein: the sum of the mass flow of the working medium flowing out of the output end of the non-final-stage impeller (2a) and the mass flow of the working medium flowing out of the output end of the final-stage impeller (2b) is equal to the total mass flow of the working medium flowing out of the storage tank (1), and the mass flow of the working medium flowing out of the output end of the final-stage impeller (2b) accounts for 20-50% of the total mass flow of the working medium flowing out of the storage tank (1).

5. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: the fuel element (7a) is made of tungsten-based metal ceramic, graphite-based composite fuel, binary carbide fuel or ternary carbide fuel.

6. The nuclear heat engine system with multistage pump interstage flow splitting according to claim 5, wherein: the tungsten-based cermet is UO₂、Gd₂O₃The graphite-based composite fuel is ZrC_x、UC_xIn admixture with graphite, the binary carbide fuel being UC_xAnd ZrC_xThe ternary carbide fuel is UC_x、NbC_xAnd ZrC_xA mixture of (a).

7. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: the side reflecting layer (7c) is made of Be or BeO.

8. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: when the reactor type is a thermal neutron reactor, the auxiliary heating element (7b) is a support tube with a slowing function, and the material of the support tube is high-temperature alloy or stainless steel; when the reactor type is a fast neutron reactor, the auxiliary heating element (7b) is a driving element and is made of the same material as the fuel element (7 a).

9. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: the working medium in the storage tank (1) is liquid hydrogen, liquid helium, liquid nitrogen, liquid oxygen or liquid methane.

10. A multi-stage pump interstage split nuclear heat engine system as claimed in claim 2 wherein: the operation process of the nuclear heat engine system is as follows:

s1, when the engine is started, the external control system controls the reactor (7) to generate nuclear fission reaction;

s2, the external control system controls the main valve (5) and the secondary control valve (6) to be opened;

s3, enabling the working medium to flow into the multi-stage pump (2) from the storage tank (1) for pressurization, enabling one path of working medium to flow out of the output end of the non-last-stage impeller (2a) of the multi-stage pump (2), and enabling the other path of working medium to flow out of the output end of the last-stage impeller (2b) of the multi-stage pump (2);

s4, enabling the working medium flowing out of the output end of the non-last-stage impeller (2a) of the multi-stage pump (2) to flow through the main valve (5), sequentially entering a regenerative cooling jacket (8a) of the thrust chamber (8) and a side reflecting layer (7c) of the reactor (7) for heat absorption, and enabling the gas working medium flowing out of the side reflecting layer (7c) to enter a collecting cavity (7 d);

s5, enabling working media flowing out of the output end of the last-stage impeller (2b) of the multi-stage pump (2) to flow through the auxiliary control valve (6), enabling the working media to enter an auxiliary heating element (7b) of a reactor (7) for absorbing heat, enabling formed gas to enter a turbine (3) for releasing heat and doing work so as to drive the multi-stage pump (2) to rotate; the gas flowing out from the outlet of the turbine (3) enters a collecting cavity (7 d);

s6, mixing the two paths of gas working media in a collecting cavity (7d) of the reactor (7), enabling the mixed working media to flow into a fuel element (7a) from the collecting cavity (7d) for convective heat absorption, enabling the temperature of the working media at an outlet of the fuel element (7a) to be more than or equal to 2500K, and enabling all the gas working media after heat absorption to enter a spray pipe (8a) for expansion work to generate thrust.

Technical Field

The invention relates to a nuclear heat engine system with multi-stage pump interstage shunting, and belongs to the field of rocket power system design.

Background

Since the 21 st century, interplanetary manned flight plans such as returning to the moon, landing on mars and the like are actively discussed in all aerospace and major countries in the world, and in order to realize corresponding space tasks, an aerospace propulsion power system is required to have higher propulsion performance. The nuclear thermal rocket engine replaces a combustion chamber of the liquid rocket engine with a nuclear fission reactor, the propellant is heated to high temperature by energy generated by nuclear fission and then expanded through the supersonic velocity spray pipe to generate thrust, and when hydrogen with the minimum molecular weight is used as the propellant of the nuclear thermal rocket engine, the specific impulse can reach 900s or more, which is about 2 times of that of the liquid hydrogen/liquid oxygen rocket engine, and the nuclear thermal rocket engine is ideal power for realizing a deep space exploration task.

The nuclear thermal rocket engine has the characteristics of single propellant and no combustion process, and suitable system schemes comprise a closed expansion cycle, an open expansion cycle and an air extraction cycle, wherein the closed expansion cycle scheme is the scheme with the highest specific impulse and is the optimal selection of the nuclear thermal rocket engine system scheme.

In the scheme of the closed expansion circulation system of the existing nuclear heat engine, working media are divided into two paths before entering a turbine, and the shunting position is arranged behind a pump or at the outlet of a regenerative cooling jacket of a thrust chamber. The system scheme has the problems that the pressure difference of two paths of working media reaches 2-6MPa when the two paths of working media enter a collecting cavity at the inlet of a reactor, a throttling element is required to be adopted for reducing the pressure of a high-pressure path before the two paths of working media enter the collecting cavity, the pressure is reduced to the same pressure as that of a low-pressure path, obvious pressure waste is caused, the shaft work burden of a subsystem of a turbopump is increased, and the room pressure and specific impulse of a nuclear thermal rocket engine are also limited to be improved.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the defects of the prior art are overcome, the nuclear heat engine system with the multi-stage pump interstage flow dividing function is provided, the problem that the shaft work of the turbine pump is wasted in the closed expansion circulation scheme of the existing nuclear heat rocket engine is solved, the shaft work of the turbine pump subsystem is reduced, the room pressure and the specific impulse of the nuclear heat rocket engine are improved, and the blank of the domestic low-shaft-work closed expansion circulation system scheme of the nuclear heat rocket engine is filled.

The technical solution of the invention is as follows:

a nuclear heat engine system with multi-stage pump interstage shunting comprises a storage tank, a multi-stage pump, a turbine, a shaft system, a main valve, an auxiliary control valve, a reactor and a thrust chamber; the reactor is of a cylindrical structure, the innermost layer is a fuel element, the outer side of the fuel element is coated with an auxiliary heating element, the outer side of the auxiliary heating element is coated with a side reflecting layer, and a collecting cavity is arranged above the fuel element and the auxiliary heating element; a plurality of holes are arranged inside the fuel element and the auxiliary heating element; the thrust chamber comprises a spray pipe and a regenerative cooling jacket, wherein the regenerative cooling jacket is positioned outside the spray pipe; working medium channels communicated with each other are processed in the regenerative cooling jacket and the side reflecting layer, and working medium inlet channels and working medium outlet channels communicated with each other are processed in the auxiliary heating element;

the multistage pump is formed by connecting multistage impellers in series; the multistage pump is connected with the turbine through a shaft system, and the multistage pump, the turbine and the turbine form a turbine pump subsystem; the outlet of the storage tank is connected with the input end of a first-stage impeller of the multi-stage pump through a pipeline, the output end of a non-last-stage impeller in the multi-stage pump is connected with a main valve through a pipeline, and the main valve is connected with a working medium channel in the regenerative cooling jacket through a pipeline; the working medium channel outlet in the side reflecting layer is connected with the collecting cavity through a pipeline; the output end of the last-stage impeller of the multi-stage pump is connected with an auxiliary control valve through a pipeline, the auxiliary control valve is connected with a working medium inlet channel in an auxiliary heating element through a pipeline, a working medium outlet channel outlet in the auxiliary heating element is connected with a turbine inlet through a pipeline, and a turbine outlet is connected with a collection cavity through a pipeline; the main valve, the secondary control valve and the reactor are all connected with an external control system.

The absolute value of the pressure difference between the gas working medium entering the inlet of the collecting cavity through the working medium channel of the side reflecting layer and the gas working medium entering the inlet of the collecting cavity from the outlet of the turbine is less than or equal to 0.8 MPa.

And the output end of the non-final-stage impeller and the output end of the final-stage impeller are both provided with adjusting elements for adjusting the mass flow of the flowing working medium.

The sum of the mass flow of the working medium flowing out of the non-final-stage impeller output end and the mass flow of the working medium flowing out of the final-stage impeller output end is equal to the total mass flow of the working medium flowing out of the storage box, and the mass flow of the working medium flowing out of the final-stage impeller output end accounts for 20% -50% of the total mass flow of the working medium flowing out of the storage box.

The fuel element material is tungsten-based metal ceramic, graphite-based composite fuel, binary carbide fuel or ternary carbide fuel.

The tungsten-based cermet is UO₂、Gd₂O₃The graphite-based composite fuel is ZrC_x、UC_xIn admixture with graphite, the binary carbide fuel being UC_xAnd ZrC_xThe ternary carbide fuel is UC_x、NbC_xAnd ZrC_xA mixture of (a).

The side reflecting layer is made of Be or BeO.

When the reactor type is a thermal neutron reactor, the auxiliary heating element is a support tube with a slowing-down function, and the material of the support tube is high-temperature alloy or stainless steel; when the reactor type is a fast neutron reactor, the auxiliary heating element is a driving element and is made of the same material as the fuel element.

The working medium in the storage tank is liquid hydrogen, liquid helium, liquid nitrogen, liquid oxygen or liquid methane.

The operation process of the nuclear heat engine system is as follows:

s1, when the engine is started, the external control system controls the nuclear fission reaction of the reactor;

s2, the external control system controls the opening of the main valve and the secondary control valve;

s3, enabling the working medium to flow into the multistage pump from the storage tank for pressurization, enabling one path of working medium to flow out of the non-final-stage impeller output end of the multistage pump, and enabling the other path of working medium to flow out of the final-stage impeller output end of the multistage pump;

s4, enabling the working medium flowing out of the non-final-stage impeller output end of the multi-stage pump to flow through the main valve, sequentially entering a regenerative cooling jacket of the thrust chamber and a side reflecting layer of the reactor for absorbing heat, and enabling the gas working medium flowing out of the side reflecting layer to enter a collecting cavity;

s5, enabling working media flowing out of the last-stage impeller output end of the multi-stage pump to flow through the secondary control valve, enabling the working media to enter an auxiliary heating element of the reactor to absorb heat, enabling formed gas to enter a turbine to release heat and do work to drive the multi-stage pump to rotate; gas flowing out of the turbine outlet enters the collecting cavity;

s6, mixing the two paths of gas working media in a collecting cavity of the reactor, enabling the mixed working media to flow into a fuel element from the collecting cavity to absorb heat in a convection manner, enabling the temperature of the working media at an outlet of the fuel element to be more than or equal to 2500K, and enabling all the gas working media after heat absorption to enter a spray pipe to perform expansion work to generate thrust.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention adopts the way of flow division among the stages of the multi-stage pump to directly divide the working medium into two paths flowing out from the outlets of the blades at different stages in the multi-stage pump, and realizes that the pressures of the two paths of gas working media at the inlet of the collecting cavity 7d are almost equal, so that the shaft power waste of the turbine pump subsystem is greatly reduced, the shaft power waste value is reduced by about 75-90% compared with the prior art, and the total shaft power of the turbine pump subsystem is about 80-90% of the prior art.

(2) The invention reduces the waste of the shaft work of the subsystem of the turbine pump, leads the volume of the turbine to be smaller, and leads the blade size of the last-stage impeller of the multi-stage pump to be reduced because the working medium entering the last-stage impeller of the multi-stage pump is only partial working medium but not all working medium, thus the weight of the subsystem of the turbine pump can be reduced by 5 to 10 percent compared with the prior scheme.

(3) Under the condition of the same shaft work, compared with the prior art, the invention can improve the room pressure of the engine by 0.5-1.5MPa, the improvement proportion accounts for 10% -30% of the numerical value of the room pressure, and the specific impulse of the engine is improved by 0.8s-2s along with the improvement of the room pressure of the engine.

Drawings

FIG. 1 is a view showing the constitution of the present invention.

Detailed Description

As shown in fig. 1, the present invention provides a nuclear thermal rocket engine system with multi-stage pump inter-stage flow division, which adopts a closed expansion cycle scheme, and the system comprises: the system comprises a storage tank 1, a multistage pump 2, a turbine 3, a shaft system 4, a main valve 5, a secondary control valve 6, a reactor 7 and a thrust chamber 8.

The number of stages of the multistage pump 2 is more than or equal to 2, and the multistage pump is indicated by a two-stage pump in figure 1. Where 2a denotes the non-last stage impeller of the multi-stage pump and 2b denotes the last stage impeller of the multi-stage pump. The reactor 7 is a nuclear fission reactor, the outline of which is in a cylindrical structure, the reactor type can be a thermal neutron reactor, a fast neutron reactor and a mixed reactor, and the reactor 7 mainly comprises four parts: fuel element 7a, auxiliary heating element 7b, side reflective layer 7c and collection chamber 7 d. The thrust chamber 8 is mainly composed of two parts: a lance 8a and a regenerative cooling jacket 8 b. The innermost layer of the reactor 7 is a fuel element 7a, the outer side of the fuel element 7a is coated with an auxiliary heating element 7b, the outer side of the auxiliary heating element 7b is coated with a side reflecting layer 7c, and a collection cavity 7d is arranged above the fuel element 7a and the auxiliary heating element 7 b. A plurality of holes are arranged inside the fuel element 7a and the auxiliary heating element 7 b; the thrust chamber 8 comprises a lance 8a and a regenerative cooling jacket 8b, wherein the regenerative cooling jacket 8b is located outside the lance 8 a; working medium channels communicated with each other are processed in the regeneration cooling jacket 8b and the side reflecting layer 7c, and working medium inlet channels and working medium outlet channels communicated with each other are processed in the auxiliary heating element 7 b.

The multistage pump 2, the turbine 3 and the shaft system 4 jointly form a turbine pump subsystem. The outlet of the storage tank 1 is connected with the input end of a first-stage impeller of the multi-stage pump 2 through a pipeline, the output end of a non-last-stage impeller 2a in the multi-stage pump 2 is connected with a main valve 5 through a pipeline, and the main valve 5 is connected with a working medium channel in a regenerative cooling jacket 8b through a pipeline; the working medium channel outlet in the side reflecting layer 7c is connected with the collecting cavity 7d through a pipeline; the output end of the last-stage impeller 2b of the multi-stage pump 2 is connected with an auxiliary control valve 6 through a pipeline, the auxiliary control valve 6 is connected with a working medium inlet channel in an auxiliary heating element 7b through a pipeline, the outlet of a working medium outlet channel in the auxiliary heating element 7b is connected with the inlet of a turbine 3 through a pipeline, and the outlet of the turbine 3 is connected with a collection cavity 7d through a pipeline; the main valve 5, the secondary control valve 6 and the reactor 7 are all connected with an external control system.

Different reactor types correspond to different auxiliary heating elements, the auxiliary heating elements are support tubes with a slowing function for a thermal neutron reactor, and the auxiliary heating elements are driving elements with the same material composition as the fuel elements 7a for a fast neutron reactor.

The fuel element 7a is made of tungsten-based cermet (UO)₂、Gd₂O₃Mixture with W), graphite-based composite fuel (ZrC)_x、UC_xMixture with graphite), binary carbide fuel (UC)_xAnd ZrC_xMixtures of) or ternary carbide fuels (UC)_x、NbC_xAnd ZrC_xMixtures of (a) and (b).

When the auxiliary heating element 7b is a driving element, the material is the same as that of the fuel element 7a, and when the auxiliary heating element 7b is a support tube, the material is a high temperature alloy or stainless steel. The side reflecting layer 7c is made of Be or BeO.

The working medium flows into the multistage pump 2 from the storage tank 1 to be pressurized, interstage division is performed in the multistage pump 2, the number of interstage division paths of the working medium is 2, and the division positions are the non-final-stage impeller 2a output end and the final-stage impeller 2b output end of the multistage pump 2. Namely, one path of working medium flows out from the output end of the non-final-stage impeller 2a of the multi-stage pump 2, and the other path of working medium flows out from the output end of the final-stage impeller 2b of the multi-stage pump 2. The sum of the mass flow of the two paths of working media is equal to the total mass flow of the working media flowing out of the storage tank 1, and the mass flow of the working media flowing out of the output end of the final-stage impeller 2b accounts for 20-50% of the total mass flow of the working media flowing out of the storage tank 1.

The working medium adopted by the invention can be liquid hydrogen, liquid helium, liquid nitrogen, liquid oxygen, liquid methane and the like, the working medium states at the output end of the non-last-stage impeller 2a of the multi-stage pump and the output end of the last-stage impeller 2b of the multi-stage pump are liquid, and the working medium states at the outlet of the regenerative cooling jacket 8a and the outlet of the auxiliary heating element 7b are gas.

In the system, part of working medium flows out from the output end of the non-final-stage impeller 2a of the multi-stage pump, and the other part of working medium flows out from the output end of the final-stage impeller 2b of the multi-stage pump, and the shunting mode is called interstage shunting.

In the invention, the design of the non-final-stage impeller 2a specifically selects which stage of impeller of the multi-stage pump, the working medium mass flow distribution of the output ends of the non-final-stage impeller 2a and the final-stage impeller 2b, the working medium channel length in the regenerative cooling jacket 8b, the working medium channel length in the side reflecting layer 7c, the working medium inlet channel length and the working medium outlet channel length of the auxiliary heating element 7b needs to ensure that the pressures of the working medium from the side reflecting layer 7c and the working medium from the auxiliary heating element 7b at the inlet of the collecting cavity 7d are almost equal, and the absolute value of the pressure difference of the two working mediums is less than or equal to 0.8 MPa.

A control drum is placed in the side reflective layer 7c, which control drum, in the initial state, is facing away from the auxiliary heating element 7b and is connected to an external control system.

The specific working process of the invention is as follows:

s1, when the engine is started, the external control system sends a rotation instruction to the control drum, the control drum starts to rotate, and when the control drum faces the auxiliary heating element 7b, the nuclear fission reaction occurs in the reactor 7;

s2, the external control system controls the main valve 5 and the auxiliary control valve 6 to be opened;

s3, enabling the working medium to flow into the multi-stage pump 2 from the storage tank 1 for pressurization, enabling one path of working medium to flow out of the output end of the non-final-stage impeller 2a of the multi-stage pump 2 and enabling the other path of working medium to flow out of the output end of the final-stage impeller 2b of the multi-stage pump 2;

s4, enabling the working medium flowing out of the output end of the non-final-stage impeller 2a of the multistage pump 2 to flow through the main valve 5, sequentially entering the regenerative cooling jacket 8a of the thrust chamber 8 and the side reflecting layer 7c of the reactor 7 for heat absorption, and enabling the gas working medium flowing out of the side reflecting layer 7c to enter the collecting cavity 7 d; the temperature of the working medium at the outlet of the side reflecting layer 7c is 200K-600K;

s5, enabling the working medium flowing out of the output end of the last-stage impeller 2b of the multistage pump 2 to flow through the auxiliary control valve 6, enabling the working medium to enter an auxiliary heating element 7b of the reactor 7 to absorb heat, enabling all formed gas to enter the turbine 3 to perform heat release and work so as to drive the multistage pump 2 to rotate, and enabling the temperature of the working medium at the outlet of the auxiliary heating element 7b to be 600-1200K; the gas flowing out of the outlet of the turbine 3 enters the collecting chamber 7 d;

s6, mixing the two paths of gas working media in a collecting cavity 7d of the reactor 7, enabling the mixed working media to flow into a fuel element 7a from the collecting cavity 7d for heat convection, enabling the temperature of the working media at an outlet of the fuel element 7a to be more than or equal to 2500K, and enabling all the gas working media after heat absorption to enter a spray pipe 8a for expansion work to generate thrust.

By adopting the system, the shaft work of the turbine pump subsystem is 80-90% of that of the prior art, and the weight of the turbine pump subsystem is reduced by 5-10% compared with that of the prior art. Meanwhile, the chamber pressure of the engine is improved by 0.5MPa to 1.5MPa compared with the prior art scheme, and the specific impulse of the engine is improved by 0.8s to 2s compared with the prior art scheme.

The invention is not described in detail and is within the knowledge of a person skilled in the art.