Same-stroke oil supply adjusting structure and method for small gas turbine engine

Abstract

The invention discloses a same-stroke oil supply adjusting structure and method for a small gas turbine engine, and belongs to the field of gas turbine engine assembly design. The same-stroke oil supply adjusting structure comprises an oil injection ring, an oil return adjusting valve, a plurality of backflow centrifugal nozzles and a nozzle baffle ring. Fuel oil enters an oil supply loop in the oil injection ring from an oil inlet of the oil return adjusting valve, is supplied to the backflow centrifugal nozzles through the oil supply loop, and is injected into a combustion chamber through injection holes by the backflow centrifugal nozzles. The special design of the backflow centrifugal nozzle enables part of fuel oil to return to the piston front cavity of the backflow centrifugal nozzle through the oil return loop, the same-stroke loop and the hole, and the oil return cavity is opened for oil return according to the pressure of the piston front cavity. Working in different working modes can be carried out according to different working states of the engine, the oil supply adjusting requirements of all working conditions such as engine starting, transition state acceleration and deceleration and steady state closed loop are met, and the control response speed is increased.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine engine component design, and more specifically, relates to a parallel fuel supply regulation structure and method for a small gas turbine engine. Background Technology

[0002] Fuel regulation in gas turbine engines primarily involves redirecting excess fuel back to the fuel pump via a regulating mechanism at the fuel pump outlet, enabling on-demand fuel supply. The main fuel supply structure after the fuel pump consists mainly of fuel line nozzles and the regulating mechanism. Its structure must ensure a wide range of fuel flow variations, balancing combustion efficiency and stability requirements at both high and low power levels, while also meeting the response time requirements for transitional acceleration and deceleration. In the fuel supply structure after the fuel pump, the regulating mechanism is generally located independently in the flow path and is often electrically operated. Due to the compact structure and diverse nozzle types in small gas turbine engines, the layout of their fuel line nozzles varies. To ensure high control precision, the mainstream fuel line nozzle layouts for small gas turbine engines currently include ignition fuel line + centrifugal atomizing nozzle and main fuel line + centrifugal atomizing nozzle (or evaporator pipe or fuel slinger ring), as well as a single main line combined with centrifugal atomizing nozzles.

[0003] Small gas turbine engines have a compact spatial structure. Adopting a dual-fuel-line configuration not only requires more space and weight but also increases system complexity and design difficulty, reducing system maintainability and reliability. On the other hand, single-fuel-line centrifugal nozzles have drawbacks such as low fuel supply pressure leading to poor atomization quality at low pressures and excessive fuel flow leading to excessive system pressure at high pressures. Therefore, using a single-line manifold and a single-fuel-line centrifugal nozzle layout results in relatively small fuel flow regulation for the entire system. Since gas turbine engines typically use multiple nozzles, the resistance matching of each nozzle is rarely considered in existing fuel supply structures (the simple matching method is not only time-consuming and labor-intensive but also often difficult to match properly, requiring special redesign and matching based on testing). This leads to uneven combustion, generating localized high temperatures that damage the combustion chamber structure. In addition, the separate electric adjustment mechanism further complicates the overall spatial layout and significantly increases manufacturing costs. Summary of the Invention

[0004] The present invention aims to address the shortcomings of the prior art by providing a parallel fuel supply regulation structure and method for a small gas turbine engine.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention first provides a parallel fuel supply regulation structure for a small gas turbine engine, which includes a fuel injection ring, a return fuel regulating valve, a plurality of return centrifugal nozzles evenly arranged in the circumferential direction within the fuel injection ring, and a nozzle retaining ring for axially fixing the return centrifugal nozzles.

[0007] The return oil regulating valve is installed on the injection ring. Its interior is divided into a piston front chamber and a piston rear chamber by a piston rod. The piston front chamber is connected to a die, and the piston rod is provided with a wedge-shaped pin that mates with the die. Adjusting the position of the piston rod can change the position of the pin in the die, thereby changing the die opening. The return oil regulating valve also has a return oil chamber, which is separated from the piston front chamber by a sealing steel ball driven by a negative feedback spring. The return oil regulating valve has an oil inlet and a return oil port that communicates with the return oil chamber. The oil inlet is connected to the oil supply loop inside the injection ring, and the oil inlet is also connected to the piston rear chamber through the oil passage and capillary damping tube inside the return oil regulating valve.

[0008] The fuel injection ring is internally provided with a fuel supply ring, a fuel return ring, and a parallel ring; the fuel supply ring is connected to each return centrifugal nozzle; the return centrifugal nozzle has two fuel passages inside, one passage leads to its nozzle for injecting fuel into the combustion chamber, and the other passage leads to the fuel return ring.

[0009] The return oil loop and the same-path loop are connected at the pipeline position furthest from the oil inlet of the return oil regulating valve; the same-path loop is connected to the orifice of the return oil regulating valve.

[0010] According to a preferred embodiment of the present invention, the reflux centrifugal nozzle includes a nozzle housing, and a nozzle seat, a swirl seat, and a sealing adjustment block sequentially disposed within the nozzle housing; the nozzle housing and the swirl seat are coaxially mounted, with a gap between them forming a fuel passage, through which fuel enters the fuel passage from a through hole provided on the nozzle housing; the end face of the swirl seat in contact with the nozzle seat is provided with a swirl groove and a central return oil hole, wherein the swirl groove connects the fuel passage and the interior of the nozzle seat to introduce fuel from the fuel passage into the nozzle seat; the central return oil hole is used to allow excess fuel to flow from the nozzle seat into the return oil passage inside the swirl seat; the nozzle seat is provided with a spray hole for spraying fuel into the combustion chamber for combustion; the sealing adjustment block is used to install the nozzle seat and the swirl seat into the nozzle housing, and its central opening allows fuel from the return oil passage inside the swirl seat to flow into the return oil loop.

[0011] The present invention also provides a method for regulating the same-path fuel supply of a gas turbine engine based on the above-mentioned same-path fuel supply regulation structure: fuel enters the fuel supply loop from the fuel inlet, and the fuel is supplied to each return centrifugal nozzle through the fuel supply loop. The return centrifugal nozzle injects fuel into the combustion chamber through the spray hole. Part of the fuel enters the return loop, and enters the piston front chamber through the return loop, the same-path loop, and the orifice.

[0012] Depending on the engine's operating state, the method includes three operating modes:

[0013] a) During steady-state operation: The pressure in the piston front chamber and piston rear chamber is equal, the piston rod stays in a fixed position, the die needle separates from the die hole, and the piston front chamber is open. When the fuel flow is small, the pressure difference between the piston front chamber and the return oil chamber is insufficient to push the sealing steel ball, so there is no return oil and the return oil chamber does not open. When the fuel flow is large enough to push the sealing steel ball, there is return oil. The fuel return oil enters the return oil chamber through the piston front chamber. When there is a certain pressure fluctuation, the piston front chamber remains open, and the return oil chamber automatically adjusts the return oil amount according to the return oil amount through the negative feedback spring to complete the negative feedback adjustment.

[0014] b) When the engine accelerates, the pressure at the fuel inlet continues to rise. Since the fuel inlet is connected to the rear chamber of the piston through a thin damping tube, the pressure in the rear chamber of the piston increases, pushing the piston rod forward. The pin fills the die hole, causing the front chamber of the piston to close. Fuel cannot enter the front chamber of the piston, thus quickly entering the combustion chamber for combustion and improving the engine performance.

[0015] c) When the engine decelerates, the pressure at the fuel inlet continues to decrease, the pressure in the piston rear chamber decreases, the piston rod moves backward, the die pin leaves the die hole, the opening of the piston front chamber increases, more fuel is diverted into the piston front chamber, the pressure in the piston front chamber increases, when the pressure reaches a certain value, the negative feedback spring begins to be compressed, the return oil chamber connects with the piston front chamber, and fuel returns through the return oil chamber, thereby reducing the amount of fuel entering the combustion chamber.

[0016] Compared with the prior art, the present invention has the following effects and advantages:

[0017] 1) Compared with the traditional dual-oil-path and single-oil-path centrifugal nozzle structure layout, the structure is compact, which reduces system complexity, system pressure, volume and weight, and improves space utilization and system reliability.

[0018] 2) This invention employs a return-flow centrifugal nozzle structure. The principle of this nozzle is essentially the same as that of a single-circuit centrifugal nozzle. The difference lies in the fact that the return-flow centrifugal nozzle has a channel before and after the swirl seat: one leads to the injection orifice, injecting fuel into the combustion chamber; the other leads to the return loop, allowing fuel to flow back to the fuel tank. Therefore, the return-flow centrifugal nozzle can be understood as being composed of two simple pressure nozzles stacked together. When the nozzle is working, the fuel flow entering the nozzle is divided into two streams: injection and return. Theoretical analysis and actual experiments show that when the inlet pressure remains constant, the total inlet fuel volume does not change significantly. Therefore, by changing the return fuel volume, the injection fuel volume also changes automatically. The return-flow nozzle utilizes this characteristic to regulate the load, giving it a wider load regulation range and a larger fuel flow regulation ratio than a single-circuit centrifugal nozzle. Therefore, the return-flow centrifugal nozzle has the advantages of simple structure and low cost compared to a dual-circuit centrifugal nozzle, and the advantages of a wider flow channel, less clogging, and a larger flow regulation ratio compared to a single-circuit centrifugal nozzle.

[0019] 3) One drawback of centrifugal return nozzles is that the return fuel volume (which affects the injection volume) is highly sensitive to changes in return fuel pressure; that is, the injection volume is highly sensitive to differences in resistance within the return fuel path. In gas turbines and aero-turbine engines using multi-nozzle fuel supply systems, this will affect the uniformity of injection volume across nozzles. This invention employs an additional parallel loop structure, ensuring that the resistance from the fuel inlet to the return fuel inlet remains essentially consistent, balancing the return fuel resistance of each nozzle and facilitating return fuel control.

[0020] 4) The pure mechanical hydraulic fuel regulating mechanism has a simple and reliable structure, positive and negative feedback, automatic adjustment capability, and fast transition acceleration and deceleration response. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the same-stage oil supply regulation mechanism;

[0022] Figure 2 This is a schematic diagram showing the connection between the fuel injection ring and the return oil regulating valve;

[0023] Figure 3 This is a schematic diagram showing the connection between the fuel injection ring and the nozzle.

[0024] Figure 4 This is a schematic diagram of the three-way annular cavity inside the fuel injection ring;

[0025] Figure 5 This is a cross-sectional view of a single-path annular cavity.

[0026] Figure 6 This is a longitudinal sectional view of the return oil regulating valve;

[0027] Figure 7 This is a cross-sectional view of the return oil regulating valve;

[0028] Figure 8 A schematic diagram of nozzle retaining ring installation;

[0029] Figure 9 A schematic diagram of a sealing connector installed in the internal oil circuit between the oil inlet and the capillary damping tube;

[0030] Figure 10 This is a schematic diagram of the capillary damping tube installation.

[0031] Figure 11 This is a schematic diagram of a reflux centrifugal nozzle;

[0032] Figure 12 Schematic diagram of the swirling channel inside a centrifugal nozzle;

[0033] Figure 13 This is a schematic diagram of the fuel flow direction inside a centrifugal recirculation nozzle.

[0034] In the diagram: 1. Injection ring, 2. Return oil regulating valve, 3. Nozzle retaining ring, 4. Return centrifugal nozzle, 11. Oil supply loop, 12. Return oil loop, 13. Same-path loop, 14. Plug, 15. Outer flange mounting hole, 16. Inner flange mounting hole, 17. Nozzle retaining ring mounting screw hole, 21. Oil inlet, 22. Oil return port, 23. Oil return chamber, 24. Piston front chamber, 25. Piston rear chamber, 26. Adapter valve block, 27. Negative feedback spring, 28. Sealing steel ball 29. Fixed orifice plate; 210. Spring; 211. Hole; 212. Pin; 213. Piston rod; 214. Piston cylinder; 215. End cap; 216. Plug; 217. Countersunk screw; 218. Sealing connector; 219. Mounting hole; 220. Mounting screw hole; 221. Capillary damping tube; 41. Sealing adjustment block; 42. Nozzle housing; 43. Swirl seat; 44. Nozzle seat; 45. Spray hole; 46. Center oil return hole; 47. Swirl groove. Detailed Implementation

[0035] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0036] like Figures 1 to 3As shown, the parallel fuel supply regulation structure for a small gas turbine engine of the present invention integrates four components: an injection ring 1, a return fuel regulating valve 2, a nozzle retaining ring 3, and a reflux centrifugal nozzle 4. The structure is compact. The return fuel regulating valve 2 is bolted to the injection ring 1. Multiple reflux centrifugal nozzles 4 are installed in axially evenly arranged seat holes on the injection ring. The nozzle retaining ring 3 is bolted to fix the reflux centrifugal nozzles 4 within the injection ring seat holes to prevent axial movement of the nozzles. The nozzle retaining ring 3 has a central opening, the size of which is larger than the nozzle orifice size of the reflux centrifugal nozzle. The parts with flow path connections between the components are sealed with sealing rings.

[0037] like Figure 4 and Figure 5 As shown, the fuel injection ring 1 is provided with a fuel supply ring 11, a fuel return ring 12 and a parallel ring 13; the fuel supply ring 11 is connected to the internal oil passage of each return centrifugal nozzle 4; the return centrifugal nozzle has two oil passages inside, one passage leads to its nozzle for injecting fuel into the combustion chamber, and the other passage leads to the fuel return ring.

[0038] Specifically, such as Figures 11 to 13 As shown, in an embodiment of the present invention, the reflux centrifugal nozzle includes a nozzle housing 42, and a nozzle seat 44, a swirl seat 43, and a sealing adjustment block 41 sequentially arranged within the nozzle housing. The nozzle housing and the swirl seat are coaxially mounted, with a gap between them forming a fuel passage. Fuel enters the fuel passage through a through hole provided on the nozzle housing. The end face of the swirl seat that contacts the nozzle seat is provided with a swirl groove 47 and a central return oil hole 46. The swirl groove 47 connects the fuel passage and the interior of the nozzle seat to introduce fuel from the fuel passage into the central oil passage of the nozzle. The nozzle seat is provided with a spray hole 45 for spraying fuel into the combustion chamber for combustion. The central return oil hole 46 is used to allow excess fuel to flow from the nozzle seat into the return oil passage inside the swirl seat. Therefore, part of the fuel flows through the fuel injector and the spray hole to be sprayed into the combustion chamber for combustion, and the other part enters the return oil loop through the central return oil hole. The sealing adjustment block 41 is used to install the nozzle seat and the swirl seat into the nozzle housing. Then, the sealing adjustment block, swirl seat, and nozzle seat are connected and sealed through the axial end face. By controlling the axial length of the sealing adjustment block, the nozzle can have axial preload after being installed and fixed by the nozzle retaining ring to ensure axial end face sealing.

[0039] like Figure 2 ,、 Figures 6 to 10As shown, the return oil regulating valve 2 is divided into a piston front chamber 24 and a piston rear chamber 25 by a piston rod 213. The piston front chamber 24 is connected to a shaped hole 211. A wedge-shaped pin 212 that mates with the shaped hole is provided on the piston rod. Adjusting the position of the piston rod can change the position of the pin in the shaped hole, thereby changing the opening of the shaped hole. The return oil regulating valve also has a return oil chamber 23. The return oil chamber 23 is separated from the piston front chamber 24 by a sealing steel ball 28 driven by a negative feedback spring 27. The return oil regulating valve 2 has an oil inlet 21 and a return oil port 22 that communicates with the return oil chamber 23. The oil inlet 21 is connected to the oil supply ring 11 inside the injection ring. The oil inlet 21 is also connected to the piston rear chamber 25 through the oil passage starting inside the return oil regulating valve 2 and the capillary damping tube 221. The inner diameter of the capillary damping tube is between 0.4 and 1.5 mm. The specific value needs to be determined based on the dynamic adjustment characteristics of the fuel and the response time. In addition, the acceleration response time can be designed by selecting different inner diameters and lengths of the capillary damping tube.

[0040] In a specific embodiment of the present invention, the negative feedback spring is disposed in the oil return chamber, which drives the sealing steel ball to block the connection between the oil return chamber and the piston front chamber; when the pressure difference between the oil return chamber and the piston front chamber is greater than the elastic force of the negative feedback spring, the negative feedback spring is compressed, and the oil return chamber and the piston front chamber are connected. A spring 210 is disposed in the piston front chamber 24, and the spring 210 is connected to the piston rod 213. The piston rod moves slightly due to the pressure difference between the piston front chamber and the piston rear chamber. When the piston rod moves, it drives the spring to move until the spring elastic force balances the pressure difference.

[0041] In a specific embodiment of the present invention, the opening direction of the shaped hole 211 is the same as the moving direction of the piston rod, and the shaped hole is opened directly opposite the position of the shaped pin on the piston rod; the size of the shaped pin gradually increases from the tip to the tail, wherein the size of the tail end fixed to the piston rod is the same as the size of the shaped hole. It should be noted that the shape of the shaped pin 212 from the tip to the tail can be linear or non-linear, and can be adjusted and determined according to the oil supply characteristics and through experimental testing.

[0042] In a specific embodiment of the present invention, the oil supply loop, the oil return loop, and the same-path loop are all annular oil passages opened around the circumference of the oil injection ring within the oil injection ring; the oil supply loop is connected to the oil inlet at the installation position of the oil return regulating valve 2; and the same-path loop is connected to the orifice at the installation position of the oil return regulating valve.

[0043] Working principle: The fuel inlet and outlet are both located on the return fuel regulating valve. Fuel enters from the fuel pump outlet into the inlet 21 of the return fuel regulating valve 2, and then enters the fuel supply loop 11 within the injection ring 1. The fuel supply loop 11 is connected to each return centrifugal nozzle 4. A portion of the fuel enters the combustion chamber through the injection orifice 45 for atomization and combustion, while the excess fuel enters the return fuel loop 12 through the central return fuel hole 46. At the position furthest from the inlet and outlet of the return fuel regulating valve, the return fuel loop 12 connects with the return fuel flow loop 12. Loop 13 is interconnected, and the same-path loop is connected to the return oil regulating valve 2. The additional same-path loop can effectively balance the return oil resistance of each nozzle, thereby maintaining a relatively stable return oil pressure. Therefore, after entering the same-path loop 13, the fuel returns to the return oil regulating valve 2, flows through the piston front chamber 24 and the return oil chamber 23, and finally returns to the fuel pump through the return oil port 22. At the same time, there is a control oil circuit in the valve that connects the fuel supply loop 11 to the piston rear chamber 25 via the capillary damping tube 221. Inside the return oil regulating valve 2, the states of various mechanisms inside the valve vary depending on the engine operating state.

[0044] Specifically, depending on the engine's operating state, the method includes three operating modes:

[0045] a) During steady-state operation: The pressures in the piston front chamber 24 and piston rear chamber 25 are equal, the piston rod 213 is stationary at a fixed position, the die pin 212 is separated from the die hole 211, and the piston front chamber 24 is open. When the fuel flow is small, the pressure difference between the piston front chamber 24 and the return oil chamber 23 is insufficient to push the sealing steel ball 28, so there is no return oil and the return oil chamber 23 is not open. When the fuel flow is large enough to push the sealing steel ball 28, there is return oil. The returned fuel enters the return oil chamber 23 through the piston front chamber 24. When there is a certain pressure fluctuation, the piston front chamber 24 remains open, and the return oil chamber 23 automatically adjusts the return oil amount according to the return oil amount through the negative feedback spring 27 to complete the negative feedback adjustment.

[0046] b) When the engine accelerates, the pressure at the oil inlet 21 continues to rise. Since the oil inlet 21 is connected to the piston rear chamber 25 through the thin damping tube 221, the pressure in the piston rear chamber 25 increases, pushing the piston rod 213 forward. The pin 212 fills the hole 211, causing the piston front chamber 24 to close. Fuel cannot enter the piston front chamber 24, thus quickly entering the combustion chamber for combustion and improving the engine state.

[0047] c) When the engine decelerates, the pressure at the fuel inlet 21 continuously decreases, the pressure in the piston rear chamber 25 decreases, the piston rod 213 moves backward, the die pin 212 leaves the die hole 211, the opening of the piston front chamber 24 increases, more fuel is diverted into the piston front chamber 24, and the pressure in the piston front chamber increases. When the pressure reaches a certain value, the negative feedback spring begins to compress, the return oil chamber connects with the piston front chamber, and fuel returns through the return oil chamber, thereby reducing the amount of fuel entering the combustion chamber. It can be seen that the deceleration phase is exactly the opposite of the acceleration phase.

[0048] In practical applications, the fuel regulation pattern can be modified and adjusted by changing the shape and position of the needle, the size and length of the capillary damping tube, the size of the orifice, the spring stiffness, the piston diameter, etc., to suit the needs of specific application scenarios.

[0049] This invention employs a return-flow centrifugal nozzle structure. The principle of this nozzle is essentially the same as that of a single-circuit centrifugal nozzle. The difference lies in the fact that the return-flow centrifugal nozzle 4 has a channel before and after the swirl seat 43: one leads to the injection hole 45, injecting fuel into the combustion chamber (referred to as the swirl channel in this invention); the other leads to the return loop 12, allowing fuel to flow back to the fuel tank (referred to as the central return hole 46 in this invention). Therefore, the return-flow centrifugal nozzle 4 can be understood as being formed by two simple pressure nozzles stacked together. When the nozzle is working, the fuel flow entering the nozzle is divided into two streams: injection and return. Theoretical analysis and actual experiments show that when the inlet pressure remains constant, the total inlet fuel volume does not change significantly. Therefore, by changing the return fuel volume, the injection fuel volume also changes automatically. The return-flow nozzle utilizes this characteristic to regulate the load, giving it a wider load regulation range and a greater fuel flow regulation ratio than the single-circuit centrifugal nozzle. Therefore, the return-oil centrifugal nozzle has the advantages of simple structure and low cost compared with the dual-oil-path centrifugal nozzle, and the advantages of wide flow channel, less clogging and large flow rate adjustment ratio compared with the single-oil-path centrifugal nozzle.

[0050] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A parallel-type fuel supply regulation structure for a small gas turbine engine, characterized in that, It includes an injection ring, a return oil regulating valve, multiple circumferentially uniformly arranged centrifugal nozzles in the injection ring, and a nozzle retaining ring for axially fixing the circumferential centrifugal nozzles. The return oil regulating valve is installed on the injection ring. Its interior is divided into a piston front chamber and a piston rear chamber by a piston rod. The piston front chamber is connected to a die, and the piston rod is provided with a wedge-shaped pin that mates with the die. Adjusting the piston position can change the position of the pin in the die, thereby changing the die opening. The return oil regulating valve also has a return oil chamber, which is separated from the piston front chamber by a sealing steel ball driven by a negative feedback spring. The return oil regulating valve has an oil inlet and a return oil port that communicates with the return oil chamber. The oil inlet is connected to the oil supply loop inside the injection ring, and the oil inlet is also connected to the piston rear chamber through the oil passage and capillary damping tube inside the return oil regulating valve. The injection ring is internally provided with a fuel supply ring, a fuel return ring, and a parallel ring; the fuel supply ring is connected to the internal oil circuit of each return centrifugal nozzle; the return centrifugal nozzle has two oil circuit channels, one channel leads to its injection hole for injecting fuel into the combustion chamber, and the other channel leads to the fuel return ring. The return oil loop and the same-path loop are connected at the pipeline position furthest from the oil inlet of the return oil regulating valve; the same-path loop is connected to the orifice of the return oil regulating valve.

2. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, The oil supply loop, oil return loop, and parallel loop are all annular oil passages opened around the circumference of the oil injection ring within the oil injection ring; the oil supply loop is connected to the oil inlet at the installation position of the oil return regulating valve; and the parallel loop is connected to the orifice at the installation position of the oil return regulating valve.

3. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, A spring is installed in the front chamber of the piston. The spring is connected to the piston rod. The piston rod moves slightly due to the pressure difference between the front and rear chambers of the piston. When the piston rod moves, it drives the movement until the spring force balances the pressure difference.

4. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 3, characterized in that, The opening direction of the die hole is the same as the moving direction of the piston rod, and the die hole is opened directly opposite the die pin position on the piston rod; the size of the die pin gradually increases from the tip to the tail, wherein the tail end fixed to the piston rod has the same size as the die hole.

5. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, The negative feedback spring is installed in the oil return chamber, which drives the sealing steel ball to block the connection between the oil return chamber and the piston front chamber. When the pressure difference between the oil return chamber and the piston front chamber is greater than the elastic force of the negative feedback spring, the negative feedback spring is compressed, and the oil return chamber and the piston front chamber are connected.

6. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, The inner diameter of the capillary damping tube is between 0.4 and 1.5 mm.

7. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, The reflux centrifugal nozzle is installed inside the injection ring through the nozzle mounting hole. The reflux centrifugal nozzle is fixed by the nozzle retaining ring. The nozzle retaining ring has a central hole, the size of which is larger than the nozzle orifice size of the reflux centrifugal nozzle.

8. The same-path fuel supply regulation structure for a small gas turbine engine according to claim 1, characterized in that, The centrifugal nozzle includes a nozzle housing, and a nozzle seat, a swirl seat, and a sealing adjustment block arranged sequentially within the nozzle housing. The nozzle housing and the swirl seat are coaxially mounted, with a gap between them forming a fuel passage. Fuel enters the fuel passage through a through hole on the nozzle housing. The end face of the swirl seat that contacts the nozzle seat is provided with a swirl groove and a central return oil hole. The swirl groove connects the fuel passage and the interior of the nozzle seat to introduce fuel from the fuel passage into the nozzle seat. The central return oil hole is used to allow excess fuel to flow from the nozzle seat into the return oil passage inside the swirl seat. The nozzle seat is provided with a spray hole to spray fuel into the combustion chamber for combustion. The sealing adjustment block is used to install the nozzle seat and the swirl seat into the nozzle housing.

9. A method for regulating the fuel supply of a gas turbine engine based on the same-range fuel supply regulation structure according to any one of claims 1-8, characterized in that, Fuel enters the fuel supply loop from the fuel inlet, and is supplied to each return centrifugal nozzle through the fuel supply loop. The return centrifugal nozzle injects fuel into the combustion chamber through the spray hole. Part of the fuel enters the return loop, and enters the piston front chamber through the return loop, the same path loop, and the orifice. Depending on the engine's operating state, the method includes a steady-state operating mode, an engine acceleration mode, and an engine deceleration mode. In steady-state operation, the pressure in the piston front chamber and piston rear chamber is equal, the piston rod remains in a fixed position, and the die needle separates from the die hole. At this time, the piston front chamber is open. When the fuel flow is small, the pressure difference between the piston front chamber and the return oil chamber is insufficient to push the sealing steel ball, so there is no return oil and the return oil chamber does not open. When the fuel flow is large enough to push the sealing steel ball, there is return oil. The returned fuel enters the return oil chamber through the piston front chamber. When there is pressure fluctuation, the piston front chamber remains open, and the return oil chamber automatically adjusts the return oil amount according to the return oil amount through the negative feedback spring to complete the negative feedback regulation.

10. The method for regulating fuel supply in a gas turbine engine according to claim 9, characterized in that, When the engine accelerates, it enters the engine acceleration mode; the pressure at the fuel inlet continues to rise. Because the fuel inlet is connected to the piston rear chamber through the capillary damping tube, the pressure in the piston rear chamber increases, pushing the piston rod forward. The pin fills the die hole, causing the piston front chamber to close, preventing fuel from entering the piston front chamber, thus allowing it to quickly enter the combustion chamber for combustion and improve engine performance. When the engine decelerates, it enters the engine deceleration mode; the pressure at the fuel inlet continues to decrease, the pressure in the piston rear chamber decreases, the piston rod moves backward, the die needle leaves the die hole, the opening of the piston front chamber increases, more fuel is diverted into the piston front chamber, the pressure in the piston front chamber increases, when the pressure reaches the set value, the negative feedback spring begins to be compressed, the return oil chamber is connected to the piston front chamber, and fuel returns through the return oil chamber, thereby reducing the amount of fuel entering the combustion chamber.

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