CN109989832A - An expansion precooling cycle system for aerospace engine - Google Patents

Abstract

The invention discloses an expansion and pre-cooling cycle system for aerospace engines, comprising a heat exchange expansion unit. In a single basic heat exchange expansion unit, heat is absorbed from the outside through a heat exchanger, and a low temperature fuel is used as a working medium for turbo expansion. The power is output to the outside by the low-temperature fuel working fluid, which continuously absorbs heat and performs work in a plurality of connected basic heat exchange expansion units, making full use of the large heat sink of the low-temperature fuel and the heat sink after the work is expanded by the endothermic working fluid. The characteristics of the whole device make the whole device have greater heat absorption under the limited low-temperature fuel flow, so that the amount of low-temperature fuel required for cooling is not greater than the amount of combustion, and the power can be output to the outside. This expansion cooling cycle system is used in aerospace After the aircraft power system is installed, the cooling ability of low-temperature fuel as a cold source can be fully utilized to meet the requirements of supersonic vehicles, hypersonic vehicles and single/dual-stage orbiting spacecraft.

Description

An expansion precooling cycle system for aerospace engine

technical field

The invention relates to the technical field of aerospace, in particular to an expansion precooling cycle system for aerospace engines.

Background technique

In the military and civilian fields, there is an urgent need for high-speed aircraft and to reduce the cost of space launch. Therefore, supersonic, hypersonic vehicles and single/dual-stage orbiting spacecraft have become one of the research hotspots in the aerospace field.

At present, the main problem of the above-mentioned aircraft is that due to the high temperature generated by the stagnation of high-speed airflow during high-speed flight, the existing aircraft and their power cannot fully meet the requirements of supersonic aircraft, hypersonic aircraft and single/dual-stage orbiting spacecraft due to their respective reasons. Require. By using the low-temperature fuel used by the aircraft as a cold source to cool the incoming high-temperature air flow, the shortcomings of the existing aircraft and their power can be overcome, and it is the best choice for the power system of supersonic aircraft, hypersonic aircraft and single/dual-stage orbiting spacecraft. A new technological path.

However, as far as the prior art is concerned, the current precoolers mostly use low-temperature fuel for aerospace as a cold source. Due to the high temperature and high heat after the stagnation of the incoming high-speed airflow, the amount of low-temperature fuel required for cooling is greater than the amount of combustion. A large amount of fuel is directly discharged, resulting in a serious waste of fuel. In addition, the heat absorbed by the fuel from the high-temperature air is not fully utilized. Therefore, the power performance of the aircraft using the existing pre-cooling method is poor, and its power specific impulse and thrust-weight ratio are small, which cannot meet the requirements of supersonic aircraft, hypersonic aircraft and single/double-stage orbiting spacecraft.

Therefore, how to provide an expansion pre-cooling cycle system for aerospace engines so as to give full play to the cooling capacity of low-temperature fuel as a cold source is a technical problem to be solved urgently by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide an expansion pre-cooling cycle system for aerospace engines, so as to give full play to the cooling ability of low-temperature fuel as a cold source.

In order to achieve the above object, the present invention provides the following technical solutions:

An expansion precooling cycle system for an aerospace engine, comprising a heat exchange expansion unit, the heat exchange expansion unit comprising a heat exchanger, a first pipeline, a second pipeline, a third pipeline, a valve and a medium turbine, wherein,

The outlet of the cold side of the heat exchanger is communicated with the first pipe, and the outlet of the medium turbine is communicated with the third pipe,

The inlet of the second pipe is communicated with the first pipe, the outlet of the second pipe is communicated with the third pipe, and the valve is arranged on the second pipe,

The inlet of the medium turbine is communicated with the first pipeline,

The working medium on the cold side of the heat exchanger is aerospace low temperature fuel.

Preferably, there are multiple heat exchange expansion units.

Preferably, a plurality of the heat exchange and expansion units are connected in series, wherein, in two adjacent heat exchange and expansion units, the third pipe of the previous heat exchange expansion unit and the next heat exchange expansion unit The inlet of the cold side of the device is connected to form a series connection.

Preferably, the above-mentioned expansion and pre-cooling cycle system for aerospace engines further includes a fourth pipeline and a fifth pipeline, and a plurality of the heat exchange and expansion units are connected in parallel, wherein the The inlets of the cold side of the heat exchanger are all communicated with the fourth conduit, and the third conduit of each of the heat exchange and expansion units is communicated with the fifth conduit.

Preferably, the above-mentioned heat exchange expansion unit includes a parallel group unit and a series group unit,

In the series unit, a plurality of the heat exchange and expansion units are connected in series, wherein, in the two adjacent heat exchange and expansion units, the third pipe of the previous heat exchange expansion unit is connected to the next one. The inlets of the cold side of the heat exchanger of the heat exchange expansion unit are connected to form a series connection,

The parallel group unit further includes a fourth pipeline and a fifth pipeline, and a plurality of the heat exchange and expansion units are connected in parallel, wherein,

The inlet of the cold side of the heat exchanger of each of the heat exchange and expansion units communicates with the fourth conduit, and the third conduit of each of the heat exchange and expansion units communicates with the fifth conduit ,

The third pipe of the last heat exchange expansion unit in the series group unit communicates with the fourth pipe in the parallel group unit.

Preferably, the above-mentioned aerospace low-temperature fuel is liquid methane.

Preferably, the above-mentioned heat exchangers are plural.

Preferably, the above-mentioned second pipeline and the valve are plural.

The expansion precooling cycle system for aerospace engines provided by the present invention includes a heat exchange expansion unit, and the heat exchange expansion unit includes a heat exchanger, a first pipeline, a second pipeline, a third pipeline, a valve and a medium turbine, Wherein, the outlet of the cold side of the heat exchanger is communicated with the first pipe, the outlet of the medium turbine is communicated with the third pipe, and the inlet of the second pipe is communicated with the first pipe, so The outlet of the second pipe is communicated with the third pipe, the valve is arranged on the second pipe, the inlet of the medium turbine is communicated with the first pipe, and the work of the cold side of the heat exchanger is connected. The quality is aerospace cryogenic fuel.

In a single basic heat exchange expansion unit, heat is absorbed from the outside through a heat exchanger, and the turboexpansion with low temperature fuel as the working medium does work to output power to the outside, and the low temperature fuel working medium is used in multiple connected basic heat exchange expansion units. Continuously absorb heat and perform work, and make full use of the characteristics of the large heat sink of low-temperature fuel and the further increase of heat sink after the expansion of the endothermic working medium to do work, so that the entire device has a larger heat absorption under the limited low-temperature fuel flow, so that the cooling required. The amount of low-temperature fuel is not greater than the amount of combustion, and the power can be output to the outside. After this expansion cooling cycle system is used in the power system of aerospace vehicles, the cooling capacity of low-temperature fuel as a cold source can be fully utilized to meet the requirements of supersonic aircraft and hypersonic aircraft. and requirements for single/dual stage orbiting spacecraft.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of a heat exchange expansion unit provided by an embodiment of the present invention;

2 is a schematic structural diagram of a plurality of heat exchange expansion units provided in an embodiment of the present invention when they are connected in series;

3 is a schematic structural diagram of a plurality of heat exchange expansion units provided in an embodiment of the present invention when they are connected in parallel;

4 is a schematic structural diagram of a plurality of heat exchange expansion units provided in an embodiment of the present invention when they are connected in series and parallel;

FIG. 5 is a schematic structural diagram of three heat exchange expansion units connected in series according to an embodiment of the present invention.

In Figure 1-5 above:

Heat exchanger 1, valve 2, medium turbine 3, fourth pipeline 4, fifth pipeline 5, heat exchange expansion unit 6, first heat exchanger 11, first valve 12, first medium turbine 13, second heat exchange 14 , the second valve 15 , the second medium turbine 16 , and the third heat exchanger 17 .

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Please refer to FIGS. 1 to 5. FIG. 1 is a schematic structural diagram of a heat exchange and expansion unit provided by an embodiment of the present invention; FIG. 2 is a schematic structural diagram of a plurality of heat exchange and expansion units provided in an embodiment of the present invention when they are connected in series; Figure 4 is a schematic structural diagram of a plurality of heat exchange expansion units provided in an embodiment of the present invention when they are connected in parallel; Schematic diagram of the structure of heat exchange expansion units connected in series.

The expansion precooling cycle system for an aerospace engine provided by the embodiment of the present invention includes a heat exchange expansion unit 6 , and the heat exchange expansion unit 6 includes a heat exchanger 1 , a first pipeline, a second pipeline, a third pipeline, and a valve 2 and the medium turbine 3, wherein the outlet of the cold side of the heat exchanger 1 is communicated with a first pipe, the outlet of the medium turbine 3 is communicated with a third pipe, the inlet of the second pipe is communicated with the first pipe, and the outlet of the second pipe is connected with the first pipe. The third pipeline is connected, the valve 2 is arranged on the second pipeline, the flow rate of the working medium passing through the medium turbine 3 is regulated by the valve 2, the inlet of the medium turbine 3 is communicated with the first pipeline, and the working medium on the cold side of the heat exchanger 1 is aviation Aerospace low temperature fuel, aerospace low temperature fuel can be liquid methane. There are plural heat exchange expansion units 6 .

In a single basic heat exchange and expansion unit 6, heat is absorbed from the outside through the heat exchanger 1, and the medium turbine 3 using low-temperature fuel as the working medium expands and outputs power to the outside. The heat exchange and expansion unit 6 continuously absorbs heat and performs work, making full use of the characteristics of the large heat sink of low-temperature fuel and the further increase of heat sink after the expansion of the heat-absorbing working medium, so that the whole device has a larger heat absorption under the limited low-temperature fuel flow. The amount of low-temperature fuel required for cooling is not greater than the amount of combustion, and power can be output to the outside. After this expansion cooling cycle system is used in the power system of aerospace vehicles, the cooling capacity of low-temperature fuel as a cold source can be fully utilized. Meet the requirements of supersonic vehicles, hypersonic vehicles and single/dual stage orbiting spacecraft.

The expansion precooling cycle system for aerospace engines provided by the embodiments of the present invention is an expansion precooling cycle system suitable for aerospace engines, and is mainly used for supersonic aircraft, hypersonic aircraft and single/double-stage orbiting aerospace propulsion system.

During specific implementation, the plurality of heat exchange expansion units 6 may be connected in series, may be connected in parallel, or may be combined in series and parallel.

When connected in series, a plurality of heat exchange expansion units 6 are connected in series, wherein, in two adjacent heat exchange expansion units 6, the third pipe of the previous heat exchange expansion unit 6 and the inlet of the cold side of the next heat exchanger 6 connected to form a series connection.

When connected in parallel, the above-mentioned expansion precooling cycle system for aerospace engines also includes a fourth pipeline 4 and a fifth pipeline 5, and a plurality of heat exchange expansion units 6 are connected in parallel, wherein the heat exchange of each heat exchange expansion unit 6 The inlets of the cold side of the device 1 are all communicated with the fourth pipe 4 , and the third pipe of each heat exchange and expansion unit 6 is communicated with the fifth pipe 5 .

In the case of series and parallel connection, the heat exchange expansion unit 6 includes a parallel group unit and a series group unit. In the series group unit, a plurality of heat exchange expansion units 6 are connected in series. The third pipe of the heat expansion unit 6 is communicated with the inlet of the cold side of the next heat exchanger 1 to form a series connection. In the parallel group unit, the fourth pipe 4 and the fifth pipe 5 are also included. Connected in parallel, wherein the inlet of the cold side of the heat exchanger 1 of each heat exchange and expansion unit 6 is communicated with the fourth pipe 4, and the third pipe of each heat exchange and expansion unit 6 is communicated with the fifth pipe 5, in series The third pipe of the last heat exchange expansion unit 6 in the group unit communicates with the fourth pipe 4 in the parallel group unit.

In order to further optimize the above solution, in a single heat exchange expansion unit 6, there may be multiple heat exchangers 1. There may be multiple second pipes and valves 2 .

Take concatenation as an example:

The expansion precooling cycle system for an aerospace engine provided by the embodiment of the present invention includes three heat exchange expansion units 6 , and the first heat exchange expansion unit includes a first heat exchanger 11 , a first valve 12 , and a first medium turbine. 13. The second heat exchange expansion unit includes a second heat exchanger 14, a second valve 15, a second medium turbine 16, and the third heat exchange expansion unit includes a third heat exchanger 17,

The working fluid is selected as low-temperature fuel liquid methane, the inlet pressure of the system working fluid is 25MPa, the inlet temperature of the system working fluid is 100K, and the working fluid is at the outlet temperature of the first heat exchanger 11, the second heat exchanger 14, and the third heat exchanger 17. is 500K, the expansion ratios of the first medium turbine 13 and the second medium turbine 16 are both 5, and the isentropic efficiencies are both 0.8. According to the calculation and analysis, it can be concluded that the system has a working fluid inlet of 100K and an outlet of 500K. The heat is 1986.6kJ/kg, and the output power per unit working fluid flow of the system is 566.6kJ/kg; traditionally, the heat exchanger is only used to select the same working fluid and working conditions for heat exchange, and the heat absorption per unit flow working fluid is 1357.1kJ/kg , and can not output power; in contrast, the expansion precooling cycle system for aerospace engines provided by the embodiment of the present invention increases the heat absorption per unit flow of working fluid by 46.4%, and the additional output power is 566.6kJ/kg.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. a kind of expansion pre-cooling cycle system for aerospace engine, which is characterized in that including the expansion cell that exchanges heat, institute Stating heat exchange expansion cell includes heat exchanger, first pipe, second pipe, third pipeline, valve and medium turbine, wherein

The outlet of the cold side of the heat exchanger has the first pipe, and the outlet of the medium turbine has the third Pipeline,

The entrance of the second pipe is connected to the first pipe, and the outlet of the second pipe and the third pipeline connect Logical, the valve is arranged on the second pipe,

The entrance of the medium turbine is connected to the first pipe,

The working medium of the cold side of the heat exchanger is aerospace low temp fuel.

2. the expansion pre-cooling cycle system according to claim 1 for aerospace engine, which is characterized in that described The expansion cell that exchanges heat is multiple.

3. the expansion pre-cooling cycle system according to claim 2 for aerospace engine, which is characterized in that multiple The heat exchange expansion cell serial communication, wherein

In the heat exchange expansion cell of adjacent two, it is upper one it is described heat exchange expansion cell the third pipeline with it is next The entrance of the cold side of the heat exchanger is connected to, and forms serial communication.

4. the expansion pre-cooling cycle system according to claim 2 for aerospace engine, which is characterized in that also wrap The 4th pipeline and the 5th pipeline are included,

Multiple heat exchange expansion cell parallel communications, wherein

The entrance of the cold side of the heat exchanger of each heat exchange expansion cell is connected to the 4th pipeline, each described The third pipeline of heat exchange expansion cell is connected to the 5th pipeline.

5. the expansion pre-cooling cycle system according to claim 2 for aerospace engine, which is characterized in that described The expansion cell that exchanges heat includes group unit and series connection group unit in parallel,

In the series connection group unit, multiple heat exchange expansion cell serial communications, wherein the heat exchange expansion of adjacent two In unit, the heat exchange of the third pipeline and next heat exchange expansion cell of a upper heat exchange expansion cell The entrance of the cold side of device is connected to, and forms serial communication,

It further include the 4th pipeline and the 5th pipeline in the group unit in parallel, multiple heat exchange expansion cell parallel communications, In,

The entrance of the cold side of the heat exchanger of each heat exchange expansion cell is connected to the 4th pipeline, each described The third pipeline of heat exchange expansion cell is connected to the 5th pipeline,

In the series connection group unit the last one it is described heat exchange expansion cell third pipeline in the in parallel group of unit The connection of 4th pipeline.

6. the expansion pre-cooling cycle system according to claim 1 for aerospace engine, which is characterized in that described Aerospace low temp fuel is liquid methane.

7. the expansion pre-cooling cycle system according to claim 1 for aerospace engine, which is characterized in that described Heat exchanger is multiple.

8. the expansion pre-cooling cycle system according to claim 1 for aerospace engine, which is characterized in that described Second pipe and the valve are multiple.