Hybrid fuel supply device for liquid hydrocarbon fuel and gas-entrained solid fuel

Abstract

The present application relates to ramjet engine technical field, specifically to liquid hydrocarbon fuel cracking gas carries solid fuel mixed fuel supply device, fuel supply device contains fuel storage room, the piston for solid fuel push is slidably installed in fuel storage room, fuel storage room is communicated with gas collection warehouse, the device is provided with gas collection warehouse, macromolecular hydrocarbon fuel cracking gas enters the circumferential gas collection chamber through three air inlet holes, the circumferential gas collection chamber is equipped with flow guide circular platform, and the slit between flow guide circular platform and air outlet baffle is used to carry out shearing flow to solid fuel along the radial centripetal direction, and shearing flow effectively realizes the carrying and mixing of solid fuel, the air inlet slit of cracking gas is arranged in the device, the slit is composed of flow guide platform and baffle, the slit distance is small, even if a small amount of cracking gas still has a large speed to shear the solid fuel carried by the slit.

Description

Technical Field

[0001] The invention relates to the technical field of ramjet engines, and in particular to a mixed fuel supply device for liquid hydrocarbon fuel cracking gas carrying solid fuel. Background Art

[0002] The solid-liquid hybrid high-Mach ramjet is a new concept engine that uses both solid powder and liquid fuel as propellants. Its operating principle is as follows: Liquid fuel cools the supersonic combustion chamber through regenerative cooling channels, producing high-temperature, high-density fuel pyrolysis gas or vapor. The pyrolysis gas is pneumatically transported to fluidize, blend, and inject the solid powdered fuel into the combustion chamber for combustion, generating thrust using the principle of jet propulsion.

[0003] This new concept of a solid-liquid hybrid high-Mach ramjet engine uses high-energy metal or boron powder as solid propellant. It combines the advantages of liquid-fueled ramjet engines, including adjustable thrust, flexible flow control, and high specific impulse, with the safety, reliability, and simple structure of solid rocket ramjet engines. For ramjets using powdered fuel, solid powders lack inherent flow properties, resulting in poor flow controllability. The combustion chamber's thermal protection relies on passive thermal protection provided by high-temperature resistant materials. Furthermore, solid powders are difficult to ignite and burn within the combustion chamber. The advantages of using metal powder particles as fuel include chemical stability, safety, convenient storage, and a short operational response time. Furthermore, the combustion products are high-boiling-point metal oxides that are not easily dissociated. Using liquid fuel through the regenerative cooling channel to generate cracked gas, which carries the solid powder particles, imparts flow properties to the solid powder particles and significantly enhances flow controllability. The ignition and combustion of the cracked gas serves as an ignition source for the solid particles, improving the combustion characteristics of the combustion chamber. The heat absorption of the fuel during the cracking process contributes to the thermal protection of the combustion chamber.

[0004] During long-term operation, the engine needs to continuously consume the mixed fuel. After the gas-solid two-phase region of the mixed fuel is evenly mixed, it is further mixed with the incoming air in the combustion chamber and then ignited and burned. Summary of the Invention

[0005] The present invention aims to provide a mixed fuel supply device for a solid-liquid hybrid scramjet engine. Micron-sized, high-energy solid fuel is propelled by a piston. Under the shear and entrainment of cracked gas from large-molecule hydrocarbon fuels, it acquires flow properties that adapt to the engine's multi-mode operating conditions, achieving uniform mixing of the gas and solid phases in the mixed fuel supply for a solid-liquid hybrid scramjet engine.

[0006] The technical solution adopted by the present invention is: comprising a plunger pump for driving the macromolecular liquid hydrocarbon fuel, a regenerative cooling channel for cracking the macromolecular liquid hydrocarbon fuel, and a fuel supply device for carrying out flow mixing with the solid fuel;

[0007] The fuel supply device comprises a fuel storage chamber, in which a piston for solid fuel to push is slidably installed, and the fuel storage chamber is communicated with a gas collecting bin.

[0008] Furthermore, the fuel storage chamber is divided into three parts: a storage chamber straight section, a storage chamber contraction section and a thin straight section.

[0009] Furthermore, baffles are installed at both ends of the air collecting bin, namely a front baffle and a rear baffle. An air inlet is provided at an eccentric position of the front baffle, and a guide platform is provided at one end of the thin straight section of the storage chamber away from the contraction section of the storage chamber, and a narrow gap is formed between the guide platform and the rear baffle.

[0010] Furthermore, three air inlet holes are provided.

[0011] Furthermore, a piston rod is provided on the piston, and the piston rod is installed at the output end of the motor.

[0012] Furthermore, a frustum is provided at one end of the straight section of the storage chamber away from the contraction end of the storage chamber, and a baffle is installed at one end away from the straight section of the storage chamber, and the piston rod is slidably installed on the baffle.

[0013] Furthermore, a sliding bearing is installed between the baffle and the piston rod.

[0014] Furthermore, the rear baffle is connected to the front baffle by bolts.

[0015] Furthermore, a mixing pipe is installed on the rear baffle.

[0016] Furthermore, a flow regulating valve is provided at the output position of the plunger pump.

[0017] The beneficial effects of the present invention are:

[0018] The device is provided with a gas collecting chamber, and the cracked gas of the large molecular hydrocarbon fuel enters the circumferential gas collecting chamber through three air inlet holes. The circumferential gas collecting chamber is provided with a guide cone. The cracked gas shears the solid fuel along the radial centripetal direction through the slit between the guide cone and the air outlet baffle. The shear flow effectively realizes the carrying and mixing of the solid fuel. The device is provided with an air inlet slit for the cracked gas. The slit is composed of a guide table and a baffle. The slit distance is small. Even if a small amount of cracked gas passes through the slit, it still has a large speed to shear and carry the solid fuel. The solid fuel flow can be controlled by controlling the speed of the motor; the cracked gas flow rate can be controlled by the valve in the pipeline before the cracked gas diversion; the single-phase flow of the mixed fuel is separately adjusted, and the solid-gas ratio of the mixed fuel can be adjusted in a wide range, which matches the operating conditions of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is a schematic structural diagram of the mixed fuel supply device for liquid hydrocarbon fuel cracking gas carrying solid fuel according to the present invention;

[0020] Figure 2 is a schematic diagram of the fuel supply device of the present invention;

[0021] Figure 3 is a schematic cross-sectional structural diagram of the fuel supply device of the present invention;

[0022] In the figure: oil storage tank 1; plunger pump 2; flow regulating valve 3; regeneration cooling channel 4; fuel supply device 5; piston rod 51; sealing ring 52; baffle 53; piston 54; fuel storage chamber 55; air collecting chamber 56; baffle 53; air inlet 57; baffle 53; guide platform 58; mixing pipe 59; motor 6. DETAILED DESCRIPTION

[0023] Example 1

[0024] For missions with flight speeds of Mach numbers 8 to 10, a high-Mach number scramjet engine using liquid fuel cracking gas to carry solid powder particles as fuel, known as a solid-liquid hybrid scramjet engine, is proposed. The engine's fuel supply system must fluidize the solid powder particles with liquid hydrocarbon fuel, blending them with each other and carrying them into the combustion chamber for combustion. The present invention provides a fuel supply system for this engine. The solid fuel is stored in a fuel storage chamber 55, and the liquid hydrocarbon fuel is stored in an oil tank 1. During actual engine operation, the liquid hydrocarbon fuel first flows through a regenerative cooling channel on the wall of the engine's combustion chamber. Under the high temperature and high pressure of the regenerative cooling channel, the liquid hydrocarbon fuel cracks into small-molecule fuel cracking gas. The cracking gas at the cooling channel outlet enters through the air inlet of the gas collection chamber 56 and flows out through the slit of the gas collection chamber 56, shearing and entraining the solid fuel pushed by the piston 54. The solid fuel is then mixed in the blending pipe 59 before entering the engine's combustion chamber for combustion.

[0025] The present invention relates to a mixed fuel supply device for liquid hydrocarbon fuel cracking gas carrying solid fuel. The device comprises a plunger pump 2 for driving large-molecule liquid hydrocarbon fuel. The plunger pump 3 pushes the large-molecule liquid hydrocarbon fuel in an oil storage tank 1 into a regeneration cooling channel 4 of a scramjet engine. The large-molecule liquid hydrocarbon fuel absorbs heat and cracks into small-molecule cracking gas. The cracking gas at the outlet of the regeneration cooling channel 4 enters a fuel supply device 5. The fuel supply device 5 realizes the function of carrying and mixing the solid fuel.

[0026] The fuel supply device 5 includes a fuel storage chamber 55, in which solid fuel is located. A piston 54 for pushing the solid fuel is slidably installed in the fuel storage chamber 55. The fuel storage chamber 55 is connected to a gas collecting bin 56, and the solid fuel is pushed into the gas collecting bin 56 by the piston 54. The fuel storage chamber 55 and the gas collecting bin 56 are coaxially arranged. A slit is provided in the gas collecting bin 56. The liquid hydrocarbon fuel cracking gas is generated by the engine regeneration cooling channel 4 and enters the gas collecting bin 56, and flows out from the circumferential slit at the outlet of the gas collecting bin 56, thereby realizing the functions of shearing, carrying and mixing the solid fuel.

[0027] Large-molecule liquid hydrocarbon fuels: Aviation engines widely use RP-3 jet fuel, which has an average carbon content of approximately 10 per molecule. Researchers generally use n-decane as a substitute. In chemical kinetics research, molecules with lower carbon contents are referred to as small-molecule hydrocarbon fuels, such as C1-C4, which are in the gaseous fuel state, while molecules with higher carbon contents are referred to as large-molecule hydrocarbon fuels, such as C10 and C11. The term "large-molecule hydrocarbon fuel" has been widely used in various publications. For example, Zuo Jingying of Harbin Institute of Technology mentioned the use of high-temperature gaseous large-molecule hydrocarbon fuels to form supersonic films in "Study on the Cooling and Drag Reduction Characteristics of Hydrocarbon Fuel Films in Scramjet Engines." Chi Yicheng of the Hong Kong Polytechnic University mentioned in "High-Precision Thermochemical Study of the Hydrogen Abstraction Reaction of Macromolecular Branched Alkanes CnH2n+2+(H,OH,HO2)" that developing high-precision chemical reaction mechanisms for large-molecule hydrocarbon fuels is crucial to developing the chemical reaction mechanisms of aviation kerosene.

[0028] Endothermic cracking conditions and completion of the working stage: During the actual operation of a scramjet engine, the core temperature of the combustion chamber can reach 2500K, which is far higher than the melting point of the engine material. Therefore, during actual operation, the engine combustion chamber wall needs to be cooled to prevent the engine from burning. Regenerative cooling is a widely used cooling method. By casting a regenerative cooling channel 4 on the wall of the engine combustion chamber, the liquid fuel passes through the regenerative cooling channel 4 before entering the combustion chamber for combustion, and the wall is cooled by the physical and chemical heat sinks of the fuel. Since the interior of the combustion chamber is under high pressure and the outlet of the regenerative cooling channel 4 is connected to the combustion chamber, the interior of the regenerative cooling channel is also under high pressure. At the same time, the wall of the cooling channel is the wall of the engine combustion chamber, and the temperature inside the channel is very high. Under high temperature and high pressure, when the large-molecule liquid hydrocarbon fuel passes through the engine regenerative cooling channel, it will be cracked into small-molecule hydrocarbon fuel.

[0029] Therefore, the cracking heat absorption condition requires the high temperature and high pressure environment within the engine's regenerative cooling channel 4. This occurs within the regenerative cooling channel 4 on the combustion chamber wall. Cooling of the engine's combustion chamber wall is achieved by utilizing the physical heat sink of the macromolecular liquid hydrocarbon fuel and the chemical heat sink of the cracking reaction's heat absorption. The cracking reaction requires high temperature and high pressure, and the regenerative cooling channel on the combustion chamber wall provides these conditions.

[0030] Example 2

[0031] On the basis of Example 1, in this embodiment, the fuel storage chamber 55 is divided into three parts: a storage chamber straight section, a storage chamber contraction section and a thin straight section. The storage chamber contraction section is conical, and the solid fuel is pushed by the piston 54. The solid fuel enters the gas collecting bin 56 from the storage chamber straight section through the storage chamber contraction section and the thin straight section in sequence. Since the inner diameter of the fuel storage chamber 55 gradually becomes smaller during the pushing process of the solid fuel, the flow rate of the solid fuel is controlled, so that the position where the solid fuel enters the gas collecting bin 56 is located at the center of the gas collecting bin 56.

[0032] Example 3

[0033] On the basis of Example 2, in this embodiment, the gas collecting bin 56 is a ring-mounted structure, with baffles 53 installed at both ends, namely a front baffle and a rear baffle. The baffles 53 are annular thin sheets, wherein the front baffle is sleeved on the outer wall of the contraction section of the storage chamber, and its installation method is casting (known technical means such as crimping and welding can also be used). A sealing ring 52 is installed between the rear baffle and the gas collecting bin 56, and the function of sealing the gas collecting bin 56 is achieved by the two baffles 53. An air inlet hole 57 is provided at the eccentric position of the front baffle, and the thin straight section of the storage chamber is away from the contraction section of the storage chamber. A guide platform 58 is provided at one end. The guide platform 58 is coaxially arranged on the outer wall of the storage chamber contraction section. A slit is formed between the guide platform 58 and the rear baffle. The guide platform 58 is a ring-shaped structure. A buffer fillet is inverted on the edge line away from the storage chamber contraction section. The liquid hydrocarbon fuel cracking gas entering from the air inlet 57 acts on the guide platform 58 and is guided by the guide platform 58 to flow around the guide platform 58, thereby controlling the direction of the liquid hydrocarbon fuel cracking gas and realizing the functions of shearing, carrying and mixing the solid fuel in the gas collecting bin 56.

[0034] Example 4

[0035] On the basis of Example 2, in this embodiment, three air inlet holes 57 are provided, and the three air inlet holes 57 are evenly arranged along the circumference of the front baffle, thereby increasing the uniformity of gas phase distribution in the gas collecting chamber 56, ensuring the stability of the radial flow state of the gas at the slit, and realizing the shear carrying function for the solid fuel.

[0036] Example 5

[0037] On the basis of Example 1, in this embodiment, a piston rod 51 is provided on the piston 54, and the piston rod 51 is installed at the output end of the motor 6 and is driven by the motor 6. The flow rate of the solid fuel can be controlled by controlling the rotation speed of the motor 6. An annular groove is provided on the outer wall of the piston 54, and a sealing ring is installed between the annular groove and the inner wall of the straight section of the storage chamber to achieve a sealing function and prevent the solid fuel from leaking from between the inner wall of the straight section of the storage chamber and the piston 54.

[0038] Example 6

[0039] On the basis of Example 2, in this embodiment, a cone is provided at one end of the straight section of the storage chamber away from the contraction end of the storage chamber. The cone is in the shape of an annular thin sheet. A baffle is installed at one end of the straight section of the storage chamber away from the storage chamber. The baffle is in the shape of a circular thin sheet. The baffle is connected to the cone by bolts. A hole is opened at the center of the baffle and an annular boss is cast. The piston rod 51 is installed in the annular boss, and the piston rod 51 can slide freely in the annular boss.

[0040] Example 7

[0041] On the basis of Example 6, in this embodiment, a sliding bearing is installed between the annular boss and the piston rod 51, and a ball is provided inside the sliding bearing, thereby reducing the friction between the piston rod 51 and the sliding bearing.

[0042] Example 8

[0043] On the basis of Example 3, in this embodiment, a plurality of threaded holes are provided at eccentric positions of the rear baffle and the front baffle, and the rear baffle and the front baffle are connected by bolts, thereby achieving fixed position of the rear baffle.

[0044] Example 9

[0045] On the basis of Example 3, a mixing tube 59 is installed on the rear baffle in this embodiment, and the mixing tube 59 can achieve uniform mixing of the gas and solid phases entering the combustion chamber.

[0046] Example 10

[0047] On the basis of Example 1, in this embodiment, a flow regulating valve 3 is provided at the output position of the plunger pump 2. The flow regulating valve 3 can be used to control the flow of the macromolecular liquid hydrocarbon fuel, thereby adjusting the flow of the macromolecular liquid hydrocarbon fuel and achieving the solid-gas ratio of the gas-solid two-phase mixing.

[0048] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention also fall within the scope of protection of the present invention.

Claims

1. A mixed fuel supply device for cracked gas carrying solid fuel, characterized by: The invention comprises a plunger pump for driving a macromolecular liquid hydrocarbon fuel, a regenerative cooling channel for cracking the macromolecular liquid hydrocarbon fuel, and a fuel supply device for carrying and mixing the solid fuel; the fuel supply device comprises a fuel storage chamber, in which a piston for driving the solid fuel is slidably mounted, and the fuel storage chamber is connected to a gas collecting chamber; Baffles are installed at both ends of the gas collecting bin, namely a front baffle and a rear baffle. An air inlet is provided at an eccentric position of the front baffle. A guide platform is provided at one end of the thin straight section of the storage chamber away from the contraction section of the storage chamber. A slit is formed between the guide platform and the rear baffle, and the cracking gas shears the solid fuel radially and centripetally through the slit.

2. The mixed fuel supply device for cracked gas and solid fuel according to claim 1, characterized in that: The fuel storage chamber is divided into three parts: a storage chamber straight section, a storage chamber contraction section and a thin straight section.

3. The mixed fuel supply device for cracked gas and solid fuel according to claim 2, characterized in that: There are three air inlet holes.

4. The mixed fuel supply device for cracked gas and solid fuel according to claim 1, characterized in that: The piston is provided with a piston rod, which is installed at the output end of the motor.

5. The mixed fuel supply device for cracked gas and solid fuel according to claim 2, characterized in that: The end of the straight section of the storage chamber away from the contraction end of the storage chamber is provided with a round table, and the end away from the straight section of the storage chamber is installed with a baffle, and the piston rod is slidably installed on the baffle.

6. The mixed fuel supply device for cracked gas and solid fuel according to claim 5, characterized in that: A sliding bearing is installed between the baffle and the piston rod.

7. The mixed fuel supply device for cracked gas and solid fuel according to claim 1, characterized in that: The rear baffle is connected to the front baffle via bolts.

8. The mixed fuel supply device for cracked gas and solid fuel according to claim 3, characterized in that: A mixing pipe is installed on the rear baffle.

9. The mixed fuel supply device for cracked gas and solid fuel according to claim 2, characterized in that: A flow regulating valve is provided at the output position of the plunger pump.

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