Liquefied fuel droplet generation device with adjustable particle size

Abstract

The invention belongs to the technical field of aerospace propulsion, and particularly relates to a particle size adjustable liquefied fuel droplet generation device which comprises an injector shell, a linear driving assembly and an electric heating assembly. A piston is arranged in the injector shell in a sliding mode, and the head of the injector shell is used for being connected with nozzles with different diameters. The linear driving assembly is arranged at the tail part of the injector shell, and the output end of the linear driving assembly is connected with the piston; the electric heating assembly is arranged outside the injector shell and used for heating and melting fuel in the injector shell. According to the device, liquid drops can be generated for liquefied fuel which is in a solid phase at normal temperature, and research can be carried out under the actual working pressure of an engine.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aerospace propulsion, and particularly relates to a liquid fuel droplet generating device with adjustable particle size. BACKGROUND

[0002] Liquid fuel has a good application prospect in solid-liquid hybrid rocket engine and ramjet engine due to the advantages of convenient storage, good economy and controllable combustion.

[0003] At present, the research on the evolution and combustion mechanism of liquid fuel droplets in flow is not deep enough, and the premise of the related research is to establish a fuel droplet generating device with adjustable particle size and adaptability to high pressure. The existing combustion science and technology discloses a droplet generating system, which comprises a micro vacuum pump, a pipeline, an oil tank and a flat needle head. The micro vacuum pump is connected with the oil tank through the pipeline, and the oil tank is connected with the flat needle head through the pipeline. The pressure difference between the oil tank and the combustion chamber is controlled to be 0.01 MPa by the micro vacuum pump, so that the liquid fuel in the oil tank is sprayed out in the form of oil droplets after flowing through the flat needle head, so as to realize the smooth and repeatable supply of oil droplets in a low-pressure environment.

[0004] However, the existing fuel droplet generating system has the following defects: 1. The fuel flow in the oil tank is controlled by pressure difference, which is only suitable for fuels that are liquid at room temperature, and is not suitable for liquid fuels that are solid at room temperature, and cannot generate liquid droplets for liquid fuels that are solid at room temperature. 2. The working pressure range of the micro vacuum pump is limited, and the droplet generating system cannot carry out research under the actual working environment of the engine exceeding 1 MPa.

[0005] Therefore, it is necessary to provide a liquid fuel droplet generating device with adjustable particle size to solve the above problems. SUMMARY

[0006] In order to solve the problems that the existing liquid droplet generating device is only suitable for fuels that are liquid at room temperature, cannot generate liquid droplets for liquid fuels that are solid at room temperature (such as paraffin-containing fuels), and cannot carry out research under the actual working pressure (greater than 1 MPa) of the engine, the application provides a liquid fuel droplet generating device with adjustable particle size to solve the existing problems.

[0007] The first aspect of the application provides a liquid fuel droplet generating device with adjustable particle size, which adopts the following technical scheme, comprising: a syringe shell, a piston is slidably arranged in the syringe shell, and the head of the piston is used for connecting nozzles with different diameters; a linear drive assembly arranged at the tail of the syringe shell, and the output end of the linear drive assembly is connected with the piston; and an electric heating assembly arranged outside the syringe shell and used for heating and melting the fuel in the syringe shell; wherein the upper limit of the thrust of the linear drive assembly is greater than the pressure borne by the nozzle.

[0008] The further technical scheme of the present application is that the linear drive assembly comprises a stepper motor, and the output shaft of the stepper motor is connected with the piston.

[0009] The further technical scheme of the present application is that the end of the output shaft of the stepper motor is provided with external threads, and a threaded hole is formed in the piston, and the external threads of the end of the output shaft of the stepper motor are connected with the threaded hole of the piston.

[0010] The further technical scheme of the present application is that a counterbore is arranged in the radial direction of the piston, and a countersunk screw is arranged in the counterbore, and the countersunk screw is fixed with the output shaft of the stepper motor after penetrating through the piston and entering the threaded hole.

[0011] The further technical scheme of the present application is that two sealing grooves are arranged on the outer periphery of the piston, and a sealing ring is arranged in each sealing groove.

[0012] The further technical scheme of the present application is that the stepper motor is coaxially connected with the tail of the injector housing through a support.

[0013] The further technical scheme of the present application is that the electric heating assembly is a tubular ceramic electric heating ring, and the tubular ceramic electric heating ring is sleeved and fixed on the injector housing.

[0014] The further technical scheme of the present application is that the head of the injector housing is a transfusion tube with a smaller diameter than the inner diameter of the injector housing, an external thread is arranged on the outer periphery of the transfusion tube, and the nozzle is connected with the transfusion tube through the external thread and the thread of the transfusion tube. The second aspect of the present application provides a particle size adjustable liquefied fuel droplet generation method, which is generated by using the particle size adjustable liquefied fuel droplet generation device provided in the first aspect of the present application, and the liquefied fuel droplet generation comprises: The linear drive assembly drives the piston to move downward until the piston compacts the fuel and then the linear drive assembly is closed; The electric heating assembly is started to continuously heat the fuel until the fuel is completely melted and reaches a preset temperature; The linear drive assembly is started according to a preset stroke and rotating speed to drive the piston to move the molten fuel in the injector housing, and the fuel droplets reaching the designed size for analysis are formed after passing through the nozzle.

[0015] The present application has the following beneficial effects: The temperature of the electric heating assembly can be adjusted to ensure that liquefied fuels with different melting points can form liquid droplets after melting for research, thereby solving the problem that research can only be carried out on fuels in liquid phase at room temperature. The upper limit of the thrust of the stepper motor is much higher than the pressure borne by the nozzle, thereby solving the problem that liquid droplet evolution and combustion research can only be carried out under low pressure conditions. By replacing the nozzle, the throat diameter of the nozzle, the pulse frequency and the number of steps of the stepper motor can be matched to adjust the particle size of the liquid droplets, and the practicability is good. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a liquefied fuel droplet generation device with adjustable particle size according to the present invention; Figure 2 for Figure 1 Schematic diagram of the piston structure; Figure 3 for Figure 2 Sectional view of CC; Figure 4 for Figure 1 Schematic diagram of the middle support; Figure 5 for Figure 4 Sectional view of AA; Figure 6 for Figure 1 A schematic diagram of the syringe housing; Figure 7 for Figure 6 Top view; Figure 8 for Figure 6 Sectional view of BB; Figure 9 for Figure 1 Schematic diagram of the nozzle structure; Figure 10 for Figure 9 The top view in the image.

[0018] In the diagram: 1. Stepper motor; 2. Support; 3. Syringe housing; 4. Piston; 5. Nozzle; 6. Tubular ceramic heating coil. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] An embodiment of the liquefied fuel droplet generation device with adjustable particle size according to the present invention, such as... Figures 1-10As shown, it includes: a syringe housing 3, a linear drive assembly, and an electric heating assembly; the syringe housing 3, as... Figure 6 , Figure 7 and Figure 8 As shown, a piston 4 is slidably disposed inside the syringe housing 3, and the head of the syringe housing 3 is used to connect nozzles 5 of different diameters; a linear drive assembly is disposed at the tail of the syringe housing 3, and the output end of the linear drive assembly is connected to the piston 4; an electric heating group is disposed outside the syringe housing 3 and is used to heat and melt the fuel inside the syringe housing 3; wherein, the upper limit of the thrust of the linear drive assembly is greater than the pressure borne by the nozzle 5.

[0021] For example, in one specific embodiment, the linear drive assembly includes a stepper motor 1, the output shaft of which is connected to a piston 4.

[0022] For example, in one specific embodiment, the output shaft end of the stepper motor 1 is provided with an external thread. Figure 2 and Figure 3 As shown, the piston 4 has a threaded hole, and the external thread at the end of the output shaft of the stepper motor 1 connects to the threaded hole of the piston 4. Specifically, a countersunk hole is provided radially on the piston, and a countersunk screw is installed in the countersunk hole. The countersunk screw passes through the piston, enters the threaded hole, and is fixed to the output shaft of the stepper motor. Specifically, in this embodiment, two sealing grooves are provided on the outer periphery of the piston 4, and sealing rings are installed in the sealing grooves.

[0023] For example, in one specific embodiment, the stepper motor 1 is coaxially connected to the tail of the syringe housing 3 via the support 2, specifically, as shown in... Figure 4 and Figure 5 As shown, in this embodiment, connecting flanges are provided at both ends of the support 2, at the tail of the syringe housing 3, and on the housing of the stepper motor 1. The connecting flange of the housing of the stepper motor 1 is connected to the connecting flange at one end of the support 2, and the connecting flange on the syringe housing 3 is connected to the connecting flange at the other end of the support 2 by connecting screws.

[0024] For example, in one specific embodiment, the electric heating component is a tubular ceramic heating coil 6, which is fitted and fixed on the syringe housing 3; the tubular ceramic heating coil 6 is tightly wrapped around the syringe housing 3 by adjusting the fastening screws of the tubular ceramic heating coil 6 for heating the fuel.

[0025] For example, in one specific embodiment, the head of the syringe housing 3 is an infusion tube with a diameter smaller than the inner diameter of the syringe housing 3, and the outer periphery of the infusion tube is provided with external threads, such as... Figure 9 and Figure 10 As shown, nozzle 5 is connected to the infusion tube via an external thread.

[0026] A method for generating liquefied fuel droplets with adjustable particle size, using the liquefied fuel droplet generating device of the present invention, includes: controlling a linear drive assembly to drive a piston downward until the piston compacts the fuel, then shutting off the linear drive assembly; activating an electric heating assembly to continuously heat the fuel until the fuel is completely melted and reaches a preset temperature; activating the linear drive assembly according to a preset stroke and rotation speed, driving the piston to push the molten fuel inside the syringe housing to move, and forming fuel droplets of the designed size for analysis after passing through a nozzle.

[0027] Working principle When generating fuel droplets, fuel is placed in the storage chamber of syringe housing 3. Nozzle 5 is rotated and fixed to the end of the infusion tube at the end of syringe housing 3. A tubular ceramic heating coil 6 is wrapped around the outer wall of the storage chamber of syringe housing 3. Syringe housing 3 is connected to support 2 with screws. Piston 4 inside syringe housing 3 is rotated and connected to the output shaft of stepper motor 1 and secured with screws. Stepper motor 1 is then connected to support 3 with screws. Stepper motor 1 is started, and its output shaft drives piston 4 downwards to compact the fuel. Stepper motor 1 is then turned off, and tubular ceramic heating coil 6 is started to continuously heat the fuel until it is completely melted and reaches a preset temperature. Stepper motor 1 is then started according to a preset stroke and speed, driving piston 4 to move the molten fuel inside syringe housing 3. After passing through nozzle 5, the fuel droplets reach the designed size and are suitable for analysis.

[0028] The present invention will be described below with reference to specific parameters: Taking paraffin fuel as an example, the paraffin fuel inside the syringe housing 3 is heated and melted by a tubular ceramic heating coil 6 and maintained at a designed temperature of 90°C. The output shaft of the stepper motor 1 drives the piston 4 to extrude the molten paraffin fuel, which is then extruded through the nozzle 5 to form fuel droplets suitable for research. By adjusting the pulse frequency and number of steps of the stepper motor 1 to change the piston movement speed, and by using nozzles 5 with different diameters, the diameter of the generated droplets can be adjusted. The influence of the pulse frequency and number of steps of the stepper motor 1 and the diameter of the nozzle 5 on the diameter of the paraffin fuel droplets is shown in Table 1.

[0029] Table 1

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for generating liquefied fuel droplets with adjustable particle size, characterized in that, include: The syringe housing has a piston that slides inside, and its head is used to connect nozzles of different diameters. A linear drive assembly is located at the tail of the syringe housing, and its output end is connected to the piston; And an electric heating component, which is located outside the syringe housing, is used to heat and melt the fuel inside the syringe housing; wherein, the upper limit of the thrust of the linear drive component is greater than the pressure that the nozzle can withstand.

2. The liquefied fuel droplet generation device with adjustable particle size according to claim 1, characterized in that, The linear drive assembly includes: a stepper motor, the output shaft of the stepper motor, and a piston connection.

3. The liquefied fuel droplet generation device with adjustable particle size according to claim 2, characterized in that, The output shaft of the stepper motor is provided with an external thread, and the piston is provided with a threaded hole. The external thread at the output shaft end of the stepper motor is connected to the threaded hole of the piston.

4. The liquefied fuel droplet generation device with adjustable particle size according to claim 3, characterized in that, The piston has a countersunk hole in its radial direction, and a countersunk screw is installed in the countersunk hole. The countersunk screw passes through the piston, enters the threaded hole, and is fixed to the output shaft of the stepper motor.

5. The liquefied fuel droplet generation device with adjustable particle size according to claim 1, characterized in that, The piston has two sealing grooves on its outer circumference, and sealing rings are installed in the sealing grooves.

6. The liquefied fuel droplet generation device with adjustable particle size according to claim 1, characterized in that, The stepper motor is coaxially connected to the tail of the syringe housing via a support.

7. The liquefied fuel droplet generation device with adjustable particle size according to claim 1, characterized in that, The electric heating component is a tubular ceramic heating coil, which is fixed to the syringe housing.

8. The liquefied fuel droplet generation device with adjustable particle size according to claim 1, characterized in that, The head of the syringe housing is an infusion tube with a diameter smaller than the inner diameter of the syringe housing. The outer circumference of the infusion tube is provided with external threads, and the nozzle is connected to the infusion tube through the external threads.

9. A method for generating liquefied fuel droplets with adjustable particle size, characterized in that, The liquefied fuel droplet generation device with adjustable particle size according to any one of claims 1-8 is used to generate liquefied fuel droplets, wherein the liquefied fuel droplet generation includes: The linear drive assembly is controlled to move the piston downwards until the piston compacts the fuel, at which point the linear drive assembly is shut off. The electric heating element is activated to continuously heat the fuel until it is completely melted and reaches the preset temperature. The linear drive assembly is activated according to the preset stroke and speed, which drives the piston to move the molten fuel inside the syringe housing. After passing through the nozzle, it forms fuel droplets of the designed size for analysis.

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