High-combustion-efficiency grain type water ram test engine

Abstract

The invention discloses a high-combustion-efficiency grain type water stamping test engine which comprises a front end socket, an outer barrel, a rear end socket, an afterburning chamber, a spray pipe, an inner barrel, an injection part, a piston and a propellant grain, wherein the front end socket, the outer barrel, the rear end socket, the afterburning chamber and the spray pipe are sequentially connected; the front end of the front sealing head is an air inlet channel; a water inlet is formed in the outer cylinder body, and an interlayer is formed by the outer cylinder body and the inner cylinder body; a round hole is formed in the rear end of the inner cylinder and forms a water flow channel with the injection piece; a combustion chamber is formed in the inner cylinder; the front end of the piston makes contact with filling gas, and the rear end of the piston makes close contact with the propellant grain. A water flow channel is formed in an interlayer of the injection piece, and water can be injected into the combustion chamber through small round holes in the injection piece. The propellant grain is a metal-rich fuel propellant, and during combustion, water reaction metal in the propellant chemically reacts with water to release energy. When the device works, the propellant grain is gradually combusted and retreats, the filling gas pushes the piston through the gas inlet channel so that the optimal constant distance can be kept between the combustion surface of the propellant grain and the water flow nozzle, and it is guaranteed that the combustion efficiency is continuously kept in the highest state.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater power, and relates to a high combustion efficiency charge-column type water ramjet test engine. Background Art

[0002] In the mid-to-late 20th century, Russia, the United States and other countries successively proposed a new type of underwater power device, namely a water ramjet, which uses water in the working environment of underwater vehicles as an oxidant and only carries high-energy metal fuel. According to relevant reports, underwater weapons such as torpedoes that use water ramjet engine technology and "supercavitation" technology integrate high-speed penetration, high-speed attack, and high hit rate, which can greatly improve their combat performance.

[0003] The water ramjet engine is mainly composed of water inlet pipeline, water flow nozzle, combustion chamber, tail nozzle, fuel, etc. The fuel can be divided into two types: pure water reaction metal powder and water-rich reaction metal powder composite solid propellant grain. That is, the water ramjet engine can be divided into: powder water ramjet engine and grain-type water ramjet engine. Grain-type water ramjet engine has the advantages of simple structure, fast system startup response, high reliability, easy use and maintenance, etc., and has attracted widespread attention. However, during the operation of the engine, the burning surface of the propellant grain gradually retreats away from the water flow nozzle, making it difficult to ensure that the metal fuel and water are fully mixed and reacted, and then it is difficult to maintain high combustion efficiency, which affects the engine specific impulse performance. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high combustion efficiency grain-type water ramjet test engine to solve the problems of the existing grain-type water ramjet engine in which the propellant grain burns and gradually retreats away from the water nozzle during operation, the metal fuel cannot be fully mixed and reacted with water, it is difficult to maintain high-efficiency combustion, and the engine specific impulse performance is affected.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] A high combustion efficiency grain-type water ramjet test engine comprises a front head, an outer cylinder, an inner cylinder, a piston, a propellant grain, an injection piece, a rear head, an afterburner chamber, and a nozzle; the front head, the outer cylinder, the rear head, the afterburner chamber, and the nozzle are sequentially connected; the inner cylinder is arranged in the outer cylinder, the piston and the propellant grain are arranged in the inner cylinder and closely attached to the inner wall of the inner cylinder, and the annular injection piece is arranged at the rear end of the inner cylinder;

[0007] The front end interface of the front head can be connected to the external gas source, and the rear end face of the front head is in contact with the front end face of the inner cylinder; the front and rear ends of the inner cylinder are sealed by a sealing ring, and a water flow layer is formed between the inner cylinder and the outer cylinder, and a plurality of water inlets are provided on the outer cylinder, and external water flow can enter the water flow layer through the water inlets; a plurality of circular holes are circumferentially arranged at the rear of the inner cylinder and correspond to the injection piece to form a water flow channel, and the front and rear ends of the injection piece are sealed by a sealing ring and a plurality of small circular holes are circumferentially arranged on its side wall, and the water flow entering the water flow layer can be injected into the internal combustion chamber of the inner cylinder 3 in sequence through the circular holes, the water flow channel and the small circular holes; the front end of the piston can contact the gas filled in the front head interface, and the rear end is tightly adhered to the propellant grain coating.

[0008] The present invention also includes the following technical features:

[0009] Specifically, the piston is composed of two parts, the front end part is made of a heat-insulating material, and the rear end part is made of a high-temperature resistant ceramic composite material, and the two parts are tightly bonded together by an adhesive.

[0010] Specifically, the propellant grain is a water-rich reactive metal fuel propellant, including a composite solid propellant rich in Al, Mg, and Li metal powders.

[0011] Specifically, the front end surface and side wall of the propellant grain are provided with a coating layer, so that the burning surface of the propellant grain is only on the rear end surface.

[0012] Specifically, the front head is threadedly connected to the front end of the outer cylinder; the rear head is threadedly connected to the rear end of the outer cylinder, and the front end face is in contact with the end face of the injection piece; the afterburner chamber is threadedly connected to the rear head; and the nozzle is threadedly connected to the afterburner chamber.

[0013] Specifically, the nozzle is composed of a convergent section, a throat and an expansion section from front to back, the convergent section is connected to the afterburner chamber through threads, and the expansion section is connected to the outside.

[0014] Specifically, the rear head is provided with a pressure measuring interface and an ignition interface.

[0015] Specifically, the rear end surface of the propellant grain can be glued to the ignition powder package, and the ignition wire of the ignition powder package is led out through the ignition interface.

[0016] Specifically, a pressure sensor is provided at the pressure measuring interface.

[0017] The working method of the high combustion efficiency grain type water ramjet test engine is as follows: when the engine is working, the propellant grain gradually burns and retreats, the front end of the piston begins to be filled with gas to increase the pressure, and the gas pressure is used to control the movement of the piston. When the gas pressure is greater than the combustion chamber pressure, the piston can be pushed to keep the burning surface of the propellant grain and the water injection port at an optimal constant distance, thereby ensuring that the combustion efficiency is maintained at the highest state.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] The high combustion efficiency grain-type water ramjet test engine provided by the present invention utilizes gas pressure to control piston movement after the engine enters a working state. When the gas pressure is greater than the combustion chamber pressure, the propellant grain moves toward the rear end to produce a corresponding displacement. By controlling the pressure, the combustion surface of the propellant grain retreats and the water nozzle always maintains an optimal distance, ensuring that the metal fuel fully reacts with water to maintain a high combustion efficiency, generate more energy, and ensure the specific impulse performance of the engine. The high combustion efficiency grain-type water ramjet test engine lays a foundation for the development and testing of water ramjet engine prototypes, and provides a theoretical and technical basis for the application of ultra-high-speed underwater propulsion systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of the overall structure of the engine according to an embodiment of the present invention.

[0021] Figure 2 It is a three-dimensional axonometric view of the outer cylinder of the engine in an embodiment of the present invention.

[0022] Figure 3 It is a three-dimensional axonometric view of the inner cylinder of the engine in an embodiment of the present invention.

[0023] Figure 4 It is a three-dimensional axonometric view of the engine injection part in an embodiment of the present invention.

[0024] Figure 5 It is a three-dimensional axonometric view of the rear head of the engine in an embodiment of the present invention.

[0025] The meaning of each number in the figure is:

[0026] 1. Front head; 2. Outer cylinder; 3. Inner cylinder; 4. EPDM piston; 5. High temperature resistant ceramic composite material (W / UHTCs) piston; 6. Coating layer; 7. Propellant column; 8. Injection piece; 9. Rear head; 10. Afterburning chamber; 11. Nozzle; 12. Ignition charge. DETAILED DESCRIPTION

[0027] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0028] Embodiment 1:

[0029] like Figures 1 to 5As shown, this embodiment provides a high combustion efficiency grain-type water ramjet test engine, including a front head 1, an outer cylinder 2, an inner cylinder 3, a piston, a propellant grain 7, an injection piece 8, a rear head 9, a post-combustion chamber 10, and a nozzle 11; the front head 1, the outer cylinder 2, the rear head 9, the post-combustion chamber 10, and the nozzle 11 are connected in sequence; the inner cylinder 3 is arranged in the outer cylinder 2, the piston and the propellant grain 7 are arranged in the inner cylinder 3 and close to the inner wall of the inner cylinder 3, and the annular injection piece 8 is arranged at the rear end of the inner cylinder 3.

[0030] The front end interface of the front head 1 can be connected to the external air source device system, and the rear end face of the front head 1 contacts and cooperates with the front end face of the inner cylinder 3; the front and rear ends of the inner cylinder 3 are sealed by a sealing ring, and a water flow sandwich is formed between the outer cylinder 2, and a plurality of water inlets are provided on the outer cylinder 2 and the external water flow can enter the water flow sandwich through the water inlet. The water flow in the water flow sandwich provides water flow for the engine combustion chamber and cools the engine cylinder, thereby reducing the process of designing the insulation layer; the water inlet is welded to the outer cylinder 2 and connected to the external water inlet device to provide the engine with a water flow of a certain pressure, and the water inlet flow can be controlled by controlling the external pressure; a plurality of circular holes are circumferentially arranged at the rear of the inner cylinder 3 and correspond to the injection piece 8 to form a water flow channel. Specifically, the rear end of the inner cylinder 3 is designed with 24 The front and rear ends of the injection piece 8 are sealed with sealing rings and a plurality of small circular holes are arranged on the side wall. Specifically, the injection piece 8 has 8 The water entering the water flow interlayer can be injected into the combustion chamber inside the inner cylinder 3 through the circular hole, the water flow channel and the small circular hole in sequence; the water flow is injected into the combustion chamber through the small circular hole, and the water outlet of the water flow nozzle is in a spraying state by adjusting the external water inlet pressure; the water after spraying and atomization reacts with the metal fuel in the combustion chamber to release energy, and the energy does work to generate thrust. The front end of the piston can contact the gas filled in the interface of the front head 1, and the rear end is tightly adhered to the coating layer 6 of the propellant column 7 to ensure that the displacement is accurately controllable. The front end of the piston contacts the filling gas, and the gas pressure is used to control the movement of the piston. When the gas pressure is greater than the combustion chamber pressure, the propellant column 7 moves toward the rear end to produce a corresponding displacement.

[0031] The piston consists of two parts, the front end is made of insulating material, specifically an insulating material EPDM piston 4, and the rear end is made of high-temperature resistant ceramic composite material, specifically a high-temperature resistant ceramic composite material (W / UHTCs) piston 5. The two parts are tightly bonded together by an adhesive.

[0032] The propellant grain 7 is a water-rich reactive metal fuel propellant, including a composite solid propellant rich in metal powders such as Al, Mg, and Li. In this embodiment, it is a composite solid propellant rich in Al metal powder (wt 80%).

[0033] The front end face and side wall of the propellant grain 7 are provided with a coating layer 6 so that the burning surface of the propellant grain 7 is only at the rear end face.

[0034] The front head 1 is threadedly connected to the front end of the outer cylinder 2; the rear head 9 is threadedly connected to the rear end of the outer cylinder 2, and the front end face contacts and cooperates with the end face of the injection piece 8; the afterburner chamber 10 is threadedly connected to the rear head 9; the nozzle 11 is threadedly connected to the afterburner chamber 10.

[0035] The nozzle 11 is composed of a convergent section, a throat and an expansion section from front to back. The convergent section is connected to the afterburner 10 by a thread, and the expansion section is connected to the outside. The inner lining of the nozzle 11 is made of an anti-scouring material to prevent metal particles from scouring and causing the throat to become larger, the expansion ratio to change, and the specific impulse performance to be affected.

[0036] The rear end cover 9 is provided with a pressure measuring interface and an ignition interface.

[0037] The rear end surface of the propellant grain 7 can be glued to the ignition powder bag 12, and the ignition wire of the ignition powder bag 12 is led out through the ignition interface.

[0038] A pressure sensor is provided at the pressure measuring interface.

[0039] The assembly sequence of the high combustion efficiency charge-type water ramjet test engine of the present invention is as follows:

[0040] First, put a sealing ring in the sealing groove at the rear end of the front head and connect it to the outer cylinder through a threaded connection; put sealing rings in the sealing grooves at both ends of the inner cylinder and install it into the inner cavity of the outer cylinder; further, use a strong adhesive to bond the EPDM piston and the high-temperature resistant ceramic composite material piston (W / UHTCs) into one body, and install the integrated piston into the inner cavity of the inner cylinder until it reaches the predetermined positioning groove; apply strong glue to the bottom of the outer coating tube of the propellant column, and then install it into the inner cavity of the inner cylinder, and the bottom end is connected to the ceramic composite material piston. Plug contact; put sealing rings in the sealing grooves at both ends of the injection piece, install the lower end into the inner cavity of the inner cylinder, and the higher end is close to the end face of the inner cylinder; use resin glue to bond the pre-installed ignition powder bag to the end face of the propellant column, and lead the ignition wire through the ignition interface on the rear head. Immediately thereafter, the rear head is connected to the outer cylinder 2 by threads, wherein the leftmost end face of the rear head is close to the rear end face of the injection piece; put a sealing ring on the rear port of the rear head, and then connect it to the afterburner chamber by threads; connect the nozzle to the afterburner chamber by threads.

[0041] Specifically, the inner cylinder and the outer cylinder together form a water flow interlayer; the water inlet is welded on the outer cylinder, and is a channel for the external water medium to enter the interlayer chamber. At the same time, this channel forms a regenerative cooling system. The external water medium is heated in the interlayer chamber to increase the thermal efficiency of the engine. The high-speed flow of the water medium takes away a large amount of heat from the engine casing, and the temperature of the engine casing drops, which can effectively reduce the thermal protection pressure of the combustion chamber.

[0042] The engine ignition is carried out by the ignition powder package igniting the propellant column, wherein the ignition powder package is mainly composed of large black particles, small black particles, magnesium powder and polytetrafluoroethylene, and the electric ignition head is wrapped in the ignition powder package.

[0043] The pressure sensor is connected to the sensor interface on the rear head to measure the pressure changes during the engine operation process.

[0044] The assembled engine is connected to the external air supply and water supply system. The front end interface of the front head is connected to the external air intake pipeline, and the four water intake interfaces on the outer cylinder are connected to the external water intake pipeline.

[0045] Embodiment 2:

[0046] The present embodiment provides a working method of a high combustion efficiency grain-type water ramjet test engine. When the engine is working, the propellant grain gradually burns and retreats, and the front end of the piston begins to be filled with gas to increase the pressure. The gas pressure is used to control the movement of the piston. When the gas pressure is greater than the combustion chamber pressure, the piston can be pushed to keep the burning surface of the propellant grain and the water injection port at an optimal constant distance, thereby ensuring that the combustion efficiency is maintained at the highest state.

[0047] Specifically, the timing program of ignition, air intake and water intake is controlled by the external measurement and control system. After the engine receives the ignition command, the ignition charge ignites and ignites the propellant grain, and the external air intake and water intake system triggers the timing sequence to start working until the propellant grain is completely burned;

[0048] More specifically, the air intake sequence triggers the solenoid valve within 10ms after the ignition is completed, and the gas pushes the piston so that the displacement of the propellant grain is proportional to the propellant burning rate; the water intake sequence triggers the solenoid valve 200ms after the propellant grain starts to burn to open the water inlet device, so that the external water medium enters the water flow interlayer through the water inlet interface, and then the water is formed into a jet state through the water flow nozzle of the injection part to enter the combustion chamber to participate in the reaction. The gas-solid two-phase flow after the initial reaction enters the afterburning chamber to continue the reaction, and finally the working fluid formed in the afterburning chamber is ejected at high speed through the nozzle to do work, thereby generating thrust.

[0049] The present invention calibrates the water flow rate of the entire system before conducting an ignition test, that is, explores the relationship between the water flow pressure (MPa) and the water flow rate (Kg / s), so as to control the water flow pressure when the engine is working to adjust the water flow rate entering the combustion chamber; the flow calibration process is carried out before the propellant charge is loaded in the assembly sequence.

[0050] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0052] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A high combustion efficiency grain type water ramjet test engine, characterized in that: The invention comprises a front end cap (1), an outer cylinder (2), an inner cylinder (3), a piston, a propellant charge (7), an injection piece (8), a rear end cap (9), a post-combustion chamber (10), and a nozzle (11); the front end cap (1), the outer cylinder (2), the rear end cap (9), the post-combustion chamber (10), and the nozzle (11) are connected in sequence; the inner cylinder (3) is arranged in the outer cylinder (2); the piston and the propellant charge (7) are arranged in the inner cylinder (3) and are closely attached to the inner wall of the inner cylinder (3); and the annular injection piece (8) is arranged in the rear end of the inner cylinder (3); The front end interface of the front end cover (1) can be connected to an external gas source, and the rear end surface of the front end cover (1) contacts and cooperates with the front end surface of the inner cylinder (3); the front and rear ends of the inner cylinder (3) are sealed by a sealing ring, and a water flow sandwich is formed between the inner cylinder (3) and the outer cylinder (2); the outer cylinder (2) is provided with a plurality of water inlets, and external water can enter the water flow sandwich through the water inlets; a plurality of circular holes are arranged circumferentially at the rear of the inner cylinder (3) and correspond to the injection piece (8) to form a water flow channel, the front and rear ends of the injection piece (8) are sealed by a sealing ring, and a plurality of small circular holes are arranged circumferentially on its side wall, and the water flow entering the water flow sandwich can be injected into the internal combustion chamber of the inner cylinder (3) through the circular holes, the water flow channel and the small circular holes in sequence; the front end of the piston can contact the gas filled in the front end cover (1) interface, and the rear end is tightly adhered to the coating layer (6) of the propellant charge (7).

2. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The piston consists of two parts, the front end part is made of a heat-insulating material, and the rear end part is made of a high-temperature resistant ceramic composite material, and the two parts are tightly bonded together by an adhesive.

3. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The propellant grain (7) is a water-rich reactive metal fuel propellant, including a composite solid propellant rich in Al, Mg and Li metal powders.

4. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The front end surface and side wall of the propellant grain (7) are provided with a coating layer (6), so that the burning surface of the propellant grain (7) is only on the rear end surface.

5. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The front end cap (1) is threadedly connected to the front end of the outer cylinder (2); the rear end cap (9) is threadedly connected to the rear end of the outer cylinder (2), and the front end face is in contact with the end face of the injection piece (8); the afterburning chamber (10) is threadedly connected to the rear end cap (9); and the nozzle (11) is threadedly connected to the afterburning chamber (10).

6. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The nozzle (11) comprises a convergent section, a throat and an expansion section from front to back, the convergent section is connected to the afterburning chamber (10) via a thread, and the expansion section is connected to the outside.

7. The high combustion efficiency grain type water ramjet test engine according to claim 1, characterized in that: The rear end cover (9) is provided with a pressure measuring interface and an ignition interface.

8. The high combustion efficiency grain type water ramjet test engine according to claim 7, characterized in that: The rear end surface of the propellant charge column (7) can be glued to the ignition powder bag (12), and the ignition wire of the ignition powder bag (12) is led out through the ignition interface.

9. The high combustion efficiency grain type water ramjet test engine according to claim 7, characterized in that: A pressure sensor is provided at the pressure measuring interface.

10. The operating method of the high combustion efficiency grain type water ramjet test engine according to any one of claims 1 to 9, characterized in that: When the engine is working, the propellant grain gradually burns and retreats, and the front end of the piston begins to fill with gas to increase the pressure. The gas pressure is used to control the movement of the piston. When the gas pressure is greater than the combustion chamber pressure, it can push the piston to keep the burning surface of the propellant grain at an optimal constant distance from the water injection port, ensuring that the combustion efficiency is maintained at the highest state.

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