External self-adaptive pressure stabilizing nozzle suitable for high-temperature environment and adjusting method of external self-adaptive pressure stabilizing nozzle

Abstract

The invention discloses an external self-adaptive pressure stabilizing nozzle suitable for a high-temperature environment and an adjusting method of the external self-adaptive pressure stabilizing nozzle. The self-adaptive pressure stabilizing nozzle comprises a valve rod which is in threaded connection with a gland and fixed through a positioning pin, and a high-temperature alloy spring arranged on the valve rod in a sleeving mode is connected between the gland and a linear bearing in an abutting mode; the linear bearing is fixed to the valve rod, connected with the base and located between the spring and the packing sealing piece. The lower portion of the base is provided with a fuel cavity and a conical nozzle, and the packing sealing piece is arranged between the base and the valve rod to isolate high-temperature and high-pressure fluid. By adjusting the balance between the pretightening force of the high-temperature alloy spring and the fuel fluid pressure, the self-adaptive adjustment of the opening degree of the conical nozzle is realized, the injection area is dynamically controlled, and the problem of poor adaptability of a fixed spray hole to the pressure change in a cooling channel is solved; meanwhile, the external high-temperature alloy spring is completely prevented from being in contact with high-temperature cracking gas, and the failure risk of an elastic device in a high-temperature and high-pressure environment is fundamentally eliminated.

Description

Technical Field

[0001] This invention relates to the field of fuel injection and pressure control technology for scramjet engines, and in particular to an external adaptive pressure stabilizing nozzle suitable for high-temperature environments and its adjustment method. Background Technology

[0002] In certain systems, nozzles face significant operational challenges: the injected fluid must flexibly switch between liquid and high-temperature gas states, a process involving a wide temperature range and significant pressure fluctuations depending on the operating conditions. To ensure stable system operation, designing a nozzle capable of adapting to a wide temperature range and maintaining stable injection pressure is crucial. Taking a scramjet engine system as an example, hydrocarbon fuel undergoes heating, phase change, and cracking reactions within a small-diameter cooling channel, effectively absorbing heat from the engine combustion chamber for cooling. Subsequently, the cracked gas is injected into the combustion chamber for combustion, generating thrust. During this process, the nozzle must adapt to both liquid and cracked gaseous fuel states simultaneously, and must possess stable pressure regulation capabilities to cope with dynamically changing fuel pressure within the cooling channel.

[0003] However, existing scramjet engine fuel nozzle technology has significant limitations: most employ a fixed nozzle design, relying on small-diameter nozzles under cold, low-pressure conditions, while requiring a switch to large-diameter nozzles under hot, high-pressure conditions. This frequent adjustment not only complicates operation but also impacts the overall system efficiency. Although a few designs attempt to utilize high-temperature, high-pressure fluids directly acting on elastic materials to regulate flow, these materials are prone to failure under extreme conditions, leading to a decline in nozzle performance.

[0004] Further examination of existing technologies reveals that the application of pressure-adaptive nozzles is largely limited to dual-source air supply equipment, PDC drill bits, and agricultural drones. In these scenarios, the operating temperature typically does not exceed 300℃, and high-temperature adaptability is not a primary concern during design. Therefore, pressure-adaptive nozzle technology capable of simultaneously meeting the demands of both ambient temperature and high-temperature, high-pressure environments is still immature. Specifically, regarding pressure-adaptive nozzles for fuel injection, some designs control nozzle opening and closing through a combination of internal baffles and springs. However, these baffles and springs are directly exposed to the high-temperature fuel fluid, making them highly susceptible to failure under high-temperature, high-pressure conditions, thus rendering them unsuitable for high-temperature applications such as engine fuel cooling.

[0005] In summary, existing technologies are inadequate in dealing with wide temperature ranges and dynamic pressure changes, and there is an urgent need to develop a pressure-adaptive nozzle that can be used in a wider range of temperature and pressure. Summary of the Invention

[0006] This invention provides an external adaptive pressure-regulating nozzle and its adjustment method suitable for high-temperature environments, in order to solve the technical problems in scramjet engine systems where traditional nozzles cannot adapt to the wide temperature range and dynamic pressure changes caused by the switching between liquid and high-temperature gaseous fuel states, and are prone to failure and unstable adjustment of injection pressure under high-temperature and high-pressure environments.

[0007] In view of the above technical problems, embodiments of the present invention provide an external adaptive pressure stabilizing nozzle for high-temperature environments, including a valve stem, a positioning pin, a gland, a high-temperature alloy spring, a linear bearing, a packing seal, a base, a fuel chamber, and a conical nozzle;

[0008] The valve stem passes through the top of the gland and is threadedly connected to the gland. The position of the gland can be adjusted by rotating it along the axial direction of the valve stem and is fixed by the locating pin.

[0009] The high-temperature alloy spring is sleeved on the valve stem, with one end of the high-temperature alloy spring abutting against the inner top wall of the gland and the other end abutting against the first end of the linear bearing;

[0010] The linear bearing is fixedly sleeved on the valve stem, and the second end of the linear bearing is threadedly connected to the first end of the base and is disposed between the high-temperature alloy spring and the packing seal to ensure the coaxiality of the valve stem.

[0011] The packing seal is disposed between the base and the valve stem to seal the fuel chamber and isolate the high-temperature and high-pressure fluid in the fuel chamber.

[0012] The base has a fuel chamber at its lower part, and the base has a fuel inlet communicating with the fuel chamber. The conical nozzle is located at the bottom of the fuel chamber.

[0013] Optionally, the outer wall of the pressure cap is provided with a positioning hole that matches the positioning pin.

[0014] Optionally, the valve stem is provided with a connecting part with a tapered cross section, and the connecting part and the tapered nozzle form a tapered surface seal.

[0015] Optionally, the upper part of the base is provided with a connecting flange for fixing the external adaptive pressure stabilizing nozzle suitable for high-temperature environments to the engine combustion chamber wall, and the fuel chamber is connected to the engine active cooling channel through the fuel inlet.

[0016] This invention also provides a method for adjusting an external adaptive pressure stabilizing nozzle suitable for high-temperature environments, comprising:

[0017] S1. Set the preload force by rotating the pressure cap to compress the high-temperature alloy spring to the preset compression amount. The high-temperature alloy spring generates an upward preload force on the pressure cap and valve stem. Insert the positioning pin to fix the pressure cap in the axial adjustment position of the valve stem.

[0018] S2. During engine operation, fuel flows into the fuel chamber, and the fuel fluid exerts downward fluid pressure on the valve stem, which counteracts the upward preload force exerted by the high-temperature alloy spring on the valve stem.

[0019] S3. When the fluid pressure exceeds the preload threshold, the valve stem moves downward against the upward preload, the conical nozzle opens, and fuel is injected from the gap between the base and the valve stem into the engine combustion chamber. The injection area increases with the increase of fluid pressure. After depressurization, it automatically returns to its original position, forming a negative feedback pressure stabilization mechanism.

[0020] S4. Wide temperature range adaptive adjustment: In the low temperature liquid fuel stage, the fuel density is high and the flow rate is low. The injection area can be reduced by adjusting the preload generated by the high temperature alloy spring. In the high temperature cracked gas stage, the fluid density is low and the flow rate is high. The injection area can be increased by adjusting the preload generated by the high temperature alloy spring.

[0021] In this invention, by adjusting the difference between the upward preload force generated by the high-temperature alloy spring on the valve stem and the downward fluid pressure generated by the feed fluid on the valve stem, the opening of the conical nozzle is adaptively adjusted, thereby dynamically controlling the injection area. This effectively solves the problem of poor adaptability of existing fixed-orifice nozzles to dynamic changes in fuel pressure within the cooling channel. Simultaneously, the elastic device (high-temperature alloy spring) of this invention adopts an external structure, completely avoiding direct contact with the high-temperature, high-pressure pyrolysis gas generated by the thermal decomposition of fuel in the cooling channel. This fundamentally eliminates the risk of failure due to material performance degradation of the elastic device under high-temperature, high-pressure conditions, and also avoids damage to the elastic device (high-temperature alloy spring) in such environments. Furthermore, it eliminates the problem of demagnetization of magnetic materials under high-temperature, high-pressure conditions when controlling injection pressure with electromagnetic force. Through the threaded connection structure between the pressure cap and the nozzle valve stem, this invention allows for precise adjustment of the injection pressure by simply rotating the pressure cap, compressing the high-temperature alloy spring. This demonstrates advantages such as simple structure, convenient manufacturing, and efficient assembly and disassembly. In particular, the conical connection at the bottom of the valve stem and the conical nozzle's conical structure design ensure uniform fuel injection and an umbrella-like diffusion effect. This invention not only significantly expands the applicable temperature range of the nozzle, but also demonstrates excellent reliability and stability in extreme high-temperature environments. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention 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.

[0023] Figure 1 This is a cross-sectional view of an external adaptive pressure stabilizing nozzle suitable for high-temperature environments, according to an embodiment of the present invention.

[0024] The reference numerals in the accompanying drawings are as follows:

[0025] 1-Valve stem, 11-Connecting part, 2-Positioning pin, 3-Gland, 4-High temperature alloy spring, 5-Linear bearing, 6-Packing seal, 7-Base, 8-Fuel chamber, 9-Conical nozzle, 10-Fuel inlet. Detailed Implementation

[0026] To make the technical problems solved, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0027] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] like Figure 1As shown, an embodiment of the present invention provides an external adaptive pressure stabilizing nozzle suitable for high-temperature environments, including a valve stem 1, a positioning pin 2, a pressure cap 3, a high-temperature alloy spring 4, a linear bearing 5, a packing seal 6, a base 7, a fuel chamber 8, and a conical nozzle 9.

[0030] The valve stem 1 passes through the top of the pressure cap 3 and is threadedly connected to the pressure cap 3. The pressure cap 3 can be adjusted by rotating and moving along the axial direction of the valve stem 1, and is fixed by the positioning pin 2.

[0031] The high-temperature alloy spring 4 is sleeved on the valve stem 1, with one end of the high-temperature alloy spring 4 abutting against the inner top wall of the pressure cap 3 and the other end abutting against the first end of the linear bearing 5. Understandably, by using the external high-temperature alloy spring 4 sleeved on the valve stem 1, and with the fuel chamber 8 using a high-temperature resistant packing seal or a diaphragm valve seal, the external installation of the high-temperature alloy spring 4 can reduce the ambient temperature of the high-temperature alloy spring 4 and prevent a decrease in the elastic modulus of the high-temperature alloy spring 4.

[0032] The linear bearing 5 is fixedly sleeved on the valve stem 1. The second end of the linear bearing 5 is threadedly connected to the first end of the base 7 and is positioned between the high-temperature alloy spring 4 and the packing seal 6 to ensure the coaxiality of the valve stem 1.

[0033] The packing seal 6 is disposed between the base 7 and the valve stem 1 to seal the fuel chamber 8, thereby isolating the high-temperature and high-pressure fluid in the fuel chamber 8 and preventing the leakage of high-temperature and high-pressure pyrolysis gas.

[0034] The base 7 has a fuel chamber 8 at its lower part, and the base 7 has a fuel inlet 10 that communicates with the fuel chamber 8. The conical nozzle 9 is located at the bottom of the fuel chamber 8.

[0035] In one embodiment, such as Figure 1 As shown, the outer wall of the pressure cap 3 is provided with a positioning hole that is adapted to the positioning pin 2.

[0036] In one embodiment, such as Figure 1 As shown, the valve stem 1 is provided with a connecting part 11 with a tapered cross section, and the connecting part 11 and the tapered nozzle 9 form a tapered surface seal.

[0037] In one embodiment, such as Figure 1 As shown, the upper part of the base 7 is provided with a connecting flange for fixing the external adaptive pressure stabilizing nozzle suitable for high temperature environment to the engine combustion chamber wall. The fuel chamber 8 is connected to the engine active cooling channel through the fuel inlet 10.

[0038] This invention also provides a method for adjusting an external adaptive pressure stabilizing nozzle suitable for high-temperature environments, comprising:

[0039] S1. Set the preload force by rotating the pressure cap 3 to compress the high-temperature alloy spring 4 to the preset compression amount. The high-temperature alloy spring 4 generates an upward preload force on the pressure cap 3 and the valve stem 1. Insert the positioning pin 2 to fix the pressure cap 3 in the axial adjustment position of the valve stem 1.

[0040] Understandably, the gland 3 is threadedly connected to the valve stem 1. By rotating the gland 3, it can be pressed down or raised along the direction of the valve stem 1. After adjusting the position of the gland 3, the locating pin 2 is used to fix the gland 3. The inner top wall of the gland 3 directly abuts against the top of the high-temperature alloy spring 4. When the gland 3 is pressed down, the high-temperature alloy spring 4 is compressed, the elastic force is increased, and an upward elastic force is provided to the gland 3 and the valve stem 1.

[0041] S2. During engine operation, fuel flows into the fuel chamber 8, and the fuel fluid exerts downward fluid pressure on the valve stem 1, which counteracts the upward preload force exerted by the high-temperature alloy spring 4 on the valve stem 1.

[0042] Understandably, the gland 3 is threadedly connected to the valve stem 1. Adjusting the position of the gland 3 by rotating it changes the compression of the high-temperature alloy spring 4, thereby adjusting the elastic force exerted by the high-temperature alloy spring 4 on the valve stem 1. A gasket at the lower end of the high-temperature alloy spring 4 enhances structural stability and protects it from direct impact. When the fuel pressure exceeds the preload of the high-temperature alloy spring 4, the valve stem 1 moves downward, triggering the opening of the conical nozzle 9, achieving adaptive pressure regulation.

[0043] S3. Adaptive adjustment is activated. When the fluid pressure exceeds the preload threshold, the valve stem 1 moves downward against the upward preload, the conical nozzle 9 opens, and fuel is injected into the engine combustion chamber from the gap between the base 7 and the valve stem 1. The injection area increases with the increase of fluid pressure, and automatically returns to its original position after pressure relief, forming a negative feedback pressure stabilization mechanism. The preloaded high-temperature alloy spring 4 applies force to the valve stem 1 to balance the pressure in the fuel chamber 8, thereby controlling the nozzle's initial injection pressure. When the pressure in the fuel chamber 8 increases, the opening degree of the conical nozzle 9 increases, releasing part of the pressure and forming negative feedback, thus maintaining the pressure within a reasonable range to prevent a significant increase in pressure in the fuel chamber 8, which could lead to a decrease in flow rate and exacerbate high-temperature coking.

[0044] S4. Wide temperature range adaptive adjustment: In the low temperature liquid fuel stage, the fuel density is high and the flow rate is low. The injection area is reduced by adjusting the preload generated by the high temperature alloy spring 4. In the high temperature cracking gas stage, the high temperature cracking gas (temperature can reach about 800℃) is generated. The fluid density decreases and the flow rate increases. The injection area is increased by adjusting the preload generated by the high temperature alloy spring 4.

[0045] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An externally mounted adaptive pressure-regulating nozzle suitable for high-temperature environments, characterized in that, It includes a valve stem (1), a positioning pin (2), a gland (3), a high-temperature alloy spring (4), a linear bearing (5), a packing seal (6), a base (7), a fuel chamber (8), and a conical nozzle (9); The valve stem (1) passes through the top of the pressure cap (3) and is threadedly connected to the pressure cap (3). The pressure cap (3) can be adjusted by rotating and moving axially along the valve stem (1) and is fixed by the positioning pin (2). The high-temperature alloy spring (4) is sleeved on the valve stem (1), with one end of the high-temperature alloy spring (4) abutting against the inner top wall of the pressure cap (3) and the other end abutting against the first end of the linear bearing (5); The linear bearing (5) is fixedly sleeved on the valve stem (1). The second end of the linear bearing (5) is threadedly connected to the first end of the base (7) and is placed between the high-temperature alloy spring (4) and the packing seal (6) to ensure the coaxiality of the valve stem (1). The packing seal (6) is disposed between the base (7) and the valve stem (1) to seal the fuel chamber (8) and isolate the high-temperature and high-pressure fluid in the fuel chamber (8); The base (7) is provided with a fuel chamber (8) at its lower part. The base (7) is provided with a fuel inlet (10) that communicates with the fuel chamber (8). The conical nozzle (9) is provided at the bottom of the fuel chamber (8).

2. The external adaptive pressure-stabilizing nozzle suitable for high-temperature environments according to claim 1, characterized in that, The outer wall of the pressure cap (3) is provided with a positioning hole that is compatible with the positioning pin (2).

3. The external adaptive pressure-stabilizing nozzle suitable for high-temperature environments according to claim 2, characterized in that, The valve stem (1) is provided with a connecting part (11) with a tapered cross section, and the connecting part (11) and the tapered nozzle (9) form a tapered surface seal.

4. The external adaptive pressure-stabilizing nozzle suitable for high-temperature environments according to claim 3, characterized in that, The base (7) is provided with a connecting flange on the upper part for fixing the external adaptive pressure stabilizing nozzle suitable for high temperature environment to the combustion chamber wall of the engine. The fuel chamber (8) is connected to the engine active cooling channel through the fuel inlet (10).

5. A method for adjusting an external adaptive pressure-regulating nozzle suitable for high-temperature environments, characterized in that, Adjustment is achieved using an external adaptive pressure-regulating nozzle suitable for high-temperature environments as described in any one of claims 1-4, comprising: S1. Set the preload force and compress the high-temperature alloy spring (4) to the preset compression amount by rotating the pressure cap (3). The high-temperature alloy spring (4) generates an upward preload force on the pressure cap (3) and the valve stem (1). Insert the positioning pin (2) to fix the pressure cap (3) in the axial adjustment position of the valve stem (1). S2. During engine operation, fuel flows into the fuel chamber (8), and the fuel fluid generates downward fluid pressure on the valve stem (1), which counteracts the upward preload force generated by the high-temperature alloy spring (4) on the valve stem (1). S3. When the fluid pressure exceeds the threshold of the preload, the valve stem (1) moves downward against the upward preload, the conical nozzle (9) opens, and fuel is injected into the engine combustion chamber from the gap between the base (7) and the valve stem (1). The injection area increases with the increase of fluid pressure. After depressurization, it automatically returns to its original position, forming a negative feedback pressure stabilization mechanism. S4. Wide temperature range adaptive adjustment: In the low temperature liquid fuel stage, the fuel density is high and the flow rate is low. The injection area is reduced by adjusting the pre-tightening force generated by the high temperature alloy spring (4); In the high temperature cracked gas stage, the fluid density is reduced and the flow rate is increased. The injection area is increased by adjusting the pre-tightening force generated by the high temperature alloy spring (4).

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