CN114233516B

CN114233516B - Composite material detonation engine combustion chamber structure with regeneration cooling function

Info

Publication number: CN114233516B
Application number: CN202111586335.2A
Authority: CN
Inventors: 张禄; 葛海浪; 高希光; 张义宁; 宋迎东
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2021-12-23
Filing date: 2021-12-23
Publication date: 2023-05-09
Anticipated expiration: 2041-12-23
Also published as: CN114233516A

Abstract

The invention discloses a composite material detonation engine combustion chamber structure with a regeneration cooling function, wherein a combustion chamber sleeve is formed by processing a ceramic matrix composite material, at least one groove is formed in the outer wall surface of the combustion chamber sleeve, a heat exchange tube is arranged in the groove, and cooling liquid flows in the heat exchange tube. The cooling liquid flowing in the heat exchange tube is aviation kerosene used by the detonation engine, the tail end of the heat exchange tube is connected with the detonation engine, and the aviation kerosene subjected to heat exchange is directly used by the detonation engine. An interface layer is arranged between the heat exchange tube and the groove surface of the groove. The invention realizes the rapid cooling of the inner wall of the combustion chamber of the detonation engine, has simple structure, large heat exchange area and high convection heat exchange coefficient, and the ceramic matrix composite material can effectively improve the working temperature of the detonation engine and reduce the weight of the engine, thereby having good beneficial effects on improving various performances of the detonation engine.

Description

Composite material detonation engine combustion chamber structure with regeneration cooling function

Technical Field

The invention relates to the technical field of engine combustion chambers, in particular to a composite material detonation engine combustion chamber structure with a regeneration cooling function.

Background

The detonation engine is a brand new engine which utilizes detonation waves to generate thrust and is greatly different from the traditional gas turbine engine in working mode, the detonation engine utilizes the detonation waves to increase working fluid and perform isovolumetric combustion, so that the working fluid can obtain more internal energy, better cycle efficiency is achieved, the detonation engine has the advantages of high thermal cycle efficiency, simple structure, light weight, large thrust-weight ratio and the like, but the combustion chamber of the detonation engine is very complex and severe in thermal environment, the combustion chamber is a core part of the engine, when the Mach number reaches more than 6, the temperature in the combustion chamber can reach more than 2600K, and the inner wall of the combustion chamber can generate conditions of cracks, ablation, structural damage and the like, so that the high-temperature resistance and thermal protection of the combustion chamber of the engine are very important, and the high-temperature alloy cannot meet the high-temperature load of the combustion chamber.

Disclosure of Invention

The invention aims to solve the problems in the background art and provides a composite material knocking engine combustion chamber structure with a regenerative cooling function. By adopting Ceramic Matrix Composite (CMC) as the combustion chamber sleeve, the high temperature resistance of the combustion chamber can be effectively improved, the weight of the detonation engine can be reduced, the structure of the detonation engine can be simplified, and the efficiency and the thrust-weight ratio of the detonation engine can be effectively improved.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

the utility model provides a combined material detonation engine combustion chamber structure with regeneration cooling function, includes the combustion chamber sleeve, and combustion chamber sleeve one end is the combustion chamber entry, the other end is the combustion chamber export, wherein: the combustion chamber sleeve is formed by processing a ceramic matrix composite material, at least one groove is formed in the outer wall surface of the combustion chamber sleeve, a heat exchange tube is arranged in the groove, and cooling liquid flows in the heat exchange tube.

In order to optimize the technical scheme, the specific measures adopted further comprise:

the detonation engine generates detonation waves by combusting aviation kerosene, the detonation waves enter the combustion chamber sleeve from the inlet of the combustion chamber and propagate along the inner wall surface of the combustion chamber sleeve, cooling liquid flowing in the heat exchange tube is aviation kerosene used by the detonation engine, the tail end of the heat exchange tube is connected with the detonation engine, and the aviation kerosene subjected to heat exchange is directly used by the detonation engine.

The grooves are arranged along the axial direction of the combustion chamber sleeve, and heat exchange tubes are arranged in each groove.

An interface layer is arranged between the heat exchange tube and the groove surface of the groove.

The interface layer is made of graphite.

The heat exchange tube is a copper alloy tube.

The interface layer has a thickness of 1mm.

The invention has the following advantages:

1. according to the invention, the grooves are formed in the outer wall surface of the combustion chamber sleeve, the heat exchange tubes are arranged in the grooves, and cooling liquid flows in the heat exchange tubes, so that the inner wall of the combustion chamber of the detonation engine can be rapidly cooled, and the cooling device has the advantages of simple structure, large heat exchange area and high convection heat exchange coefficient.

2. The combustion chamber sleeve is processed by ceramic matrix composite materials, the ceramic matrix composite materials (CMC for short) can work for a long time at 1932K, the mass is only 1/3 of that of high-temperature alloy, and the combustion chamber sleeve can greatly improve the temperature resistance of a combustion chamber, reduce the cooling air quantity, reduce the weight of a detonation engine, improve the efficiency and thrust-weight ratio of the detonation engine and has extremely high application value for ultra-high sonic velocity aircrafts when being applied to the combustion chamber sleeve of the detonation engine.

3. The cooling liquid flowing in the heat exchange tube is aviation kerosene used by the detonation engine, the tail end of the heat exchange tube is connected with the detonation engine, and the aviation kerosene subjected to heat exchange is directly used by the detonation engine. After the temperature is raised through the cooling pipeline, the fuel is sprayed into the combustion chamber through the injector to be used as fuel, so that energy can be greatly saved, the working efficiency of the detonation engine is improved, and a regenerative cooling system is formed.

4. And a graphite interface layer is arranged between the heat exchange tube and the groove surface of the groove and is used for solving the problem of how much thermal stress is caused by expansion under the high temperature condition, and the addition of the interface layer is also beneficial to improving the heat conduction efficiency between the copper tube and the combustion chamber sleeve and enhancing the cooling effect.

Drawings

FIG. 1 is a schematic view of the structure of the present invention

FIG. 2 is a schematic cross-sectional view of a combustion chamber of the present invention;

FIG. 3 is a cross-sectional view of a groove and heat exchange tube of the present invention.

Name of the label in the figure: a combustion chamber inlet 1, a combustion chamber sleeve 2, a heat exchange tube 3, a cooling liquid inlet 4, a combustion chamber outlet 5, a cooling liquid outlet 6, an inner wall surface 7, an outer wall surface 8, a fuel gas channel 9, a cooling channel 10, a groove 11 and an interface layer 12 of the combustion chamber sleeve.

Detailed Description

Embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

Referring to fig. 1,2 and 3, an embodiment of the present invention includes:

the utility model provides a ceramic matrix composite material detonation engine combustion chamber structure with regeneration cooling function, including combustion chamber sleeve 2, heat exchange tube 3, coolant inlet 4, coolant outlet 6, combustion chamber inlet 1, combustion chamber outlet 5, gas passageway 9 and cooling passageway 10 constitute, the coolant inlet is located combustion chamber head, during operation detonation engine detonation wave propagates along combustion chamber sleeve inner wall surface 7, high temperature gas flow and inner wall surface direct contact, inner wall surface temperature rise, progressively along axial and radial conduction heat, mainly heat conduction to outer wall surface 8; the combustion chamber is an annular combustion chamber, the combustion chamber sleeve is of an annular structure, the combustion chamber sleeve is provided with an inner wall surface and an outer wall surface, a groove is formed in the outer wall surface, a copper pipe is placed, and in order to reduce thermal stress generated by high-temperature expansion between the copper pipe and the combustion chamber sleeve, an interface layer 12 is added between the copper pipe and the combustion chamber sleeve, and the interface layer is made of graphite.

As shown in figures 2 and 3, the grooves are formed in the outer wall of the combustion chamber sleeve, compared with the grooves formed in the combustion chamber sleeve, the grooves are easy to process and install a cooling pipe, the accuracy is high, the bottom edge of the groove is 10.7-16.5 mm, the two edges are arranged on the extension lines of the top points A and B of the bottom edges and the circle center O, the top edges are circular arcs C and D (C and D are the intersection points of the upper edges of the grooves and the outer wall surface), and thus the top edges of the copper alloy pipe and the outer wall surface of the combustion chamber form the complete outer wall surface of the combustion chamber.

The copper alloy tube is made of copper alloy with higher heat conductivity coefficient, the size of the copper alloy tube is consistent with the slotting size of the combustion chamber sleeve, and the thickness of the copper alloy tube is 1mm.

The width and the spacing of the cooling pipes are 1:1,1.5:1,2:1,2.5:1,3:1, the cooling effect is gradually improved under the condition that the structural stress requirement is met by the above dimensional ratios.

When the detonation engine works, high-temperature and high-frequency pressure load is generated on the inner wall of the combustion chamber, the inner wall of the combustion chamber and a high-temperature gas channel in the combustion chamber are subjected to heat convection, the temperature of the inner wall of the combustion chamber can be gradually increased, the temperature of the inner wall of the combustion chamber can be gradually conducted outwards, if a cooling system is not provided, the temperature of a sleeve barrel of the combustion chamber of the inner wall can reach more than 2500K, the structural durability of the combustion chamber of the detonation engine is affected, the service life of the combustion chamber of the engine can be greatly reduced, the sleeve barrel of the combustion chamber adopts ceramic matrix composite materials, and the ceramic matrix composite materials are made of various C/Sic materials which are woven in two dimensions, so that the detonation engine has good mechanical properties in an ultra-high temperature environment, can work for a short time at 2500K temperature and work for a long time below 1932K temperature, the cooling air quantity of the detonation engine can be reduced, the structure of the detonation engine is simplified, the weight of the detonation engine is reduced, and the efficiency and the thrust weight ratio of the detonation engine are improved; the combustion chamber sleeve is made of a two-dimensional braided C/Sic material capable of resisting high temperature, but cannot stably work under the ultra-high temperature condition for a long time, so that an active cooling structure is required to cool the combustion chamber, cooling liquid is aviation kerosene required by the operation of a detonation engine, the cooling liquid enters a copper alloy pipe from a cooling liquid inlet, fluid flows in, the concrete inflow mass is determined with the fuel consumption of the detonation engine, fuel of the detonation engine flows into the combustion chamber of the detonation engine through an injector after flowing through a cooling passage of the cooling liquid, the cooling liquid flows in the copper alloy pipe to exchange heat with the facing flow of the inner wall of the copper alloy pipe, and flows out from a cooling liquid outlet to take away heat of the copper alloy pipe. As shown in figure 3, the copper alloy tube and the combustion chamber sleeve are provided with three contact interfaces, the three contact interfaces are interface layers, the interface layers are formed by graphite, and the combustion chamber sleeve and the copper alloy tube are in a high-temperature environment when in operation, so that the combustion chamber sleeve and the copper alloy tube can be heated and expanded at high temperature, and high thermal stress is caused to the contact surfaces, the purpose of the interface layers is to effectively reduce the thermal stress, the interface layers are made of graphite, have a relatively low thermal expansion coefficient and a relatively small elastic modulus, and the size is selected between 0.5mm and 1.5mm, so that the heat transfer coefficient between the copper alloy tube and the combustion chamber sleeve can be improved.

The invention can realize the rapid cooling of the inner wall of the combustion chamber of the detonation engine, has simple structure, large heat exchange area and high convection heat exchange coefficient, and the Ceramic Matrix Composite (CMC) can effectively improve the working temperature of the detonation engine and reduce the weight of the engine, thereby having good beneficial effects on improving various performances of the detonation engine.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the invention without departing from the principles thereof are intended to be within the scope of the invention as set forth in the following claims.

Claims

1. The utility model provides a combined material detonation engine combustion chamber structure with regeneration cooling function, includes combustion chamber sleeve (2), combustion chamber sleeve (2) one end be combustion chamber entry (1), the other end is combustion chamber export (5), characterized by: the combustion chamber sleeve (2) is formed by processing a ceramic matrix composite material, at least one groove (11) is formed in the outer wall surface (8) of the combustion chamber sleeve (2), a heat exchange tube (3) is arranged in the groove (11), and cooling liquid flows in the heat exchange tube (3); the grooves (11) are arranged along the axial direction of the combustion chamber sleeve (2), and each groove (11) is internally provided with a heat exchange tube (3); an interface layer (12) is arranged between the heat exchange tube (3) and the groove surface of the groove (11); the interfacial layer (12) is made of graphite.

2. The composite detonation engine combustion chamber structure with a regenerative cooling function of claim 1, wherein: the detonation engine generates detonation waves through combusting aviation kerosene, the detonation waves enter the combustion chamber sleeve (2) from the combustion chamber inlet (1) and propagate along the inner wall surface of the combustion chamber sleeve, cooling liquid flowing in the heat exchange tube (3) is the aviation kerosene used by the detonation engine, the tail end of the heat exchange tube (3) is connected with the detonation engine, and the aviation kerosene subjected to heat exchange is directly used by the detonation engine.

3. The composite detonation engine combustion chamber structure with a regenerative cooling function of claim 2, wherein: the heat exchange tube (3) is a copper alloy tube.

4. A composite detonation engine combustion chamber structure with regenerative cooling function as claimed in claim 3 wherein: the thickness of the interface layer (12) is 1mm.