Fuel Supply System

Abstract

To provide a fuel supply system capable of suppressing an increase in size by optimizing cylinder capacity, and also suppressing deterioration of components.SOLUTION: A fuel supply system 1 comprises an ecology device 6 which collects remaining fuel in a fuel supply part 7. The ecology device 6 comprises: a first passage 11 and a second passage 12; a cylinder 10 and a piston 14 which are provided between the first passage 11 and second passage 12; an energization part 15 which energizes the piston 14; and a third passage 13 which branches off from the first passage 11 and has a check valve 25. Here in-operation first capacity B1 is larger than necessary recovery capacity D, where the in-operation first capacity B1 is capacity A1 of a first space 31 of the cylinder 10 when the gas turbine engine is in operation, and the necessary recovery capacity D is the total of fuel remaining in a fuel manifold 4 and fuel nozzle 5 when the gas turbine engine is at a stop.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fuel supply system. [Background technology]

[0002] In gas turbine engines used in aircraft and the like, there is known a fuel supply system having a fuel manifold for supplying fuel to a fuel nozzle. In these fuel supply systems, when the engine is stopped, the fuel remaining in the fuel nozzle may turn into coke, which may result in reduced engine efficiency and damage to the combustor. For this reason, various techniques have been proposed for recovering the remaining fuel in the fuel manifold when the engine is stopped.

[0003] For example, Patent Document 1 discloses an ecology valve (ecology device) for recovering and storing fuel from a fuel manifold, which includes a cylinder that communicates with a fuel pump and a fuel manifold, a piston that slides in the cylinder between an operating position when the engine is operating and a discharge position when the engine is stopped, and a muscle valve that connects a flow path on the outlet side of the cylinder to a flow path on the inlet side. According to the technology described in Patent Document 1, at the discharge position, the piston moves so as to increase the volume inside the cylinder, which makes it possible to recover residual fuel in the fuel manifold and store it in the cylinder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-11276 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 does not specify in detail the relationship between the cylinder volume and the fuel capacity. If the cylinder volume is smaller than the capacity of the residual fuel, the residual fuel in the fuel nozzle and the fuel manifold cannot be sufficiently collected, which may lead to coking of the fuel nozzle. On the other hand, if the cylinder volume is too large compared to the capacity of the residual fuel, it may lead to an increase in the size of the entire fuel supply system and an increase in costs. Therefore, the conventional technology has a problem in optimizing the cylinder volume and preventing the fuel supply system from becoming larger. Furthermore, in the technology described in Patent Document 1, the residual fuel collected when the engine is stopped flows into both spaces inside the cylinder partitioned by the piston. At this time, some of the combustion gas may be collected together with the residual fuel. Therefore, there is a risk that the collected combustion gas may oxidize the parts inside the cylinder, causing deterioration of the parts.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a fuel supply system that can prevent an increase in size by optimizing the cylinder volume and can also prevent deterioration of components. [Means for solving the problem]

[0007] In order to solve the above problems, a fuel supply system according to the invention recited in claim 1 (e.g., the fuel supply system 1 in the first embodiment) is a fuel supply system for a gas turbine engine, and includes a fuel tank (e.g., the fuel tank 2 in the first embodiment), a fuel manifold (e.g., the fuel manifold 4 in the first embodiment) that supplies fuel from the fuel tank to a fuel nozzle (e.g., the fuel nozzle 5 in the first embodiment), and an ecology device (e.g., the ecology device 6 in the first embodiment) that is provided between the fuel tank and the fuel manifold and that recovers fuel from the fuel manifold, the ecology device including a first passage (e.g., the first passage 11 in the first embodiment) connected to the fuel tank, a second passage (e.g., the second passage 12 in the first embodiment) connected to the fuel manifold, and a third passage (e.g., the second passage 13 in the first embodiment) that is provided between the first passage and the second passage and communicates with the first passage. a cylinder (e.g., the cylinder 10 in the first embodiment) having one port (e.g., the first port 21 in the first embodiment) and a second port (e.g., the second port 22 in the first embodiment) communicating with the second passage; a piston (e.g., the piston 14 in the first embodiment) that divides an internal space of the cylinder into a first space (e.g., the first space 31 in the first embodiment) communicating with the first passage and a second space (e.g., the second space 32 in the first embodiment) communicating with the second passage and sliding inside the cylinder; a biasing portion (e.g., the biasing portion 15 in the first embodiment) that biases the piston from the second port side toward the first port side; a third passage (e.g., the third passage 13 in the first embodiment) that branches off from the first passage and communicates with the second passage; and a check valve (e.g., the check valve 25 in the first embodiment) that is provided in the third passage and prevents communication from the second passage to the first passage; a fourth passage (for example, a fourth passage 314 in the third embodiment) branching off from the first passage and connected to the fuel tank; and a selective changeover valve (for example, a second valve 332 and a third valve 333 in the third embodiment) capable of switching between the first passage and the fourth passage;a volume of the cylinder is equal to a sum of a volume of the first space (e.g., volume A1 in the first embodiment) and a volume of the second space (e.g., volume A2 in the first embodiment), and when a volume of the first space of the cylinder during engine operation of the gas turbine engine is defined as a first operating volume (e.g., a first operating volume B1 in the first embodiment) and a total volume of the inside of the fuel manifold and the fuel nozzle during engine stop of the gas turbine engine is defined as a required recovery volume (e.g., a required recovery volume D in the first embodiment), the first operating volume is larger than the required recovery volume. When the engine is operating, the selective changeover valve is controlled so that the fuel flows through the first passage and is supplied to the ecology device, and when the engine is stopped, the selective changeover valve is controlled so that the fuel filled in the first space flows through the fourth passage and is returned to the fuel tank. It is characterized by the following.

[0008] In addition, in the fuel supply system according to the invention described in claim 2, the first operating volume is determined by a balance between the pressure difference between the first space and the second space and the biasing force of the biasing part when the engine is operating, and the magnitude of the biasing force of the biasing part is set so that the first operating volume is larger than the required recovery volume.

[0009] The fuel supply system according to the invention described in claim 3 further comprises a stopper (e.g., stopper 250 in the second embodiment) provided in the second space and limiting the movement of the piston toward the second port, wherein when the engine is operating, the piston abuts against the stopper, the volume of the first space in the cylinder when the piston abuts against the stopper is set to the first operating volume, and the stopper is provided at a position such that the first operating volume is larger than the required recovery volume.

[0010] In addition, the fuel supply system according to the invention recited in claim 4 is characterized in that the first operating volume is set to be equal in size to the required recovery volume.

[0011] The fuel supply system according to the invention recited in claim 5 is characterized in that it includes an on-off valve (for example, the first valve 331 in the third embodiment) provided in the first passage, and closes the on-off valve when the engine is stopped for a short period of time.

[0013] In addition, claims 6 The fuel supply system according to the invention described in ,before A three-way valve (for example, three-way valve 330 in the third embodiment) in which the on-off valve and the selective switching valve are integrated is provided at a connection portion between the first passage and the fourth passage. Effect of the Invention

[0014] According to the fuel supply system of claim 1 of the present invention, an ecology device is provided between a fuel tank and a fuel manifold, and the ecology device includes a first passage, a second passage, a cylinder having a first port and a second port, a piston, an urging part, and a third passage having a check valve. The piston divides the space inside the cylinder into a first space and a second space. When the engine is operating, fuel supplied from the fuel tank flows through the third passage and is supplied to the fuel manifold, and the piston moves toward the second port side due to the flow rate of fuel discharged from the fuel pump. The volume of the first space at this time is the first volume during operation. On the other hand, when the engine is stopped, the flow rate of fuel discharged from the fuel pump decreases, and the piston moves toward the first port side. As a result, the second space becomes negative pressure, and the residual fuel in the fuel nozzle connected to the second space of the cylinder via the second port and the second passage is collected into the second space of the cylinder. Therefore, the residual fuel can be collected when the engine is stopped, and coking of the fuel nozzle can be suppressed. The first volume during operation, which is the volume of the first space when the engine is operating, is larger than the required recovery volume, which is the total volume of the fuel in the fuel manifold and the fuel nozzle. Here, the volume of the residual fuel that can be recovered by the ecology device is equal to the volume of the second space that increases with the movement of the piston. In an aspect of the present invention, the volume of the cylinder is equal to the sum of the volumes of the first space and the second space partitioned by the piston. Therefore, the volume of the second space that increases with the movement of the piston, i.e., the volume of the residual fuel that can be recovered, is equal to the volume of the first space that decreases with the movement of the piston. According to an aspect of the present invention, since the first volume during operation is larger than the required recovery volume, the residual fuel can be reliably recovered by the piston moving to narrow the first space when the engine is stopped. In addition, the size of the first space can be set according to the volume of the residual fuel. This optimizes the cylinder volume and prevents the cylinder from becoming excessively large. Furthermore, since the recovery function can be achieved with one cylinder and piston, the configuration can be simplified and made smaller and lighter than the conventional technology in which a muscle valve is provided in addition to the cylinder and piston. In addition, the recovered residual fuel is contained only in the second space and does not flow into the first space or the first passage. This makes it possible to prevent the combustion gas from entering the supply flow path on the fuel pump side, even if the combustion gas is mixed in when the residual fuel is being recovered. This makes it possible to minimize the area that the combustion gas comes into contact with, thereby suppressing oxidation caused by the combustion gas and deterioration of parts. Therefore, it is possible to provide a fuel supply system that can prevent an increase in size by optimizing the cylinder volume and also suppress deterioration of parts. The fuel supply system also includes a fourth passage and a selective switching valve. The selective switching valve is controlled so that the fuel flows through the first passage when the engine is operating and flows through the fourth passage when the engine is stopped. In this way, the flow path through which the fuel flows is different when the engine is operating (when the fuel is being supplied) and when the engine is stopped (when the fuel is being recovered). Therefore, even when a one-way fuel pump is used, for example, the fuel can be supplied and recovered without wearing out the pump. Furthermore, since the fuel supply path and the fuel recovery path are different, it is easy to manage the amount of fuel supplied and recovered. Therefore, the amount of fuel supplied from the fuel tank to the fuel nozzle, etc. can be more precisely controlled.

[0015] According to the fuel supply system of claim 2 of the present invention, the first operating volume is determined by the balance between the pressure difference between the first space and the second space and the biasing force of the biasing part when the engine is operating. The biasing force of the biasing part is set to a magnitude such that the first operating volume is larger than the required recovery volume. By setting the biasing force of the biasing part in this manner, a desired first operating volume can be automatically ensured by the balance between the two forces when the engine is operating. Therefore, there is no need to provide a control system or the like for electrically controlling the position of the piston, and the configuration of the fuel supply system can be simplified.

[0016] According to the fuel supply system of claim 3 of the present invention, when the engine is operating, the piston abuts against a stopper provided in the second space. The stopper is provided at a position such that the volume of the first space of the cylinder (first volume during operation) becomes larger than the required recovery volume when the piston abuts against the stopper. This makes it possible to stably ensure a desired first volume during operation when the engine is operating without being affected by fluctuations in the flow rate of fuel discharged from the fuel pump. Therefore, all of the remaining fuel can be more reliably recovered when the engine is stopped.

[0017] According to the fuel supply system of claim 4 of the present invention, the first volume during operation is set to be equal to the required recovery volume. This allows the cylinder volume to be further optimized while reliably recovering the remaining fuel. This allows the size of the cylinder to be kept to a minimum, and the fuel supply system to be further miniaturized, weight-reduced, and cost-reduced.

[0018] According to the fuel supply system of claim 5 of the present invention, the first passage is provided with an on-off valve, and the on-off valve is closed when the engine is stopped for a short time. Here, for example, the engine may misfire unintentionally and the engine may be stopped for a short time. In such a case, since the engine needs to be restarted immediately, it is desirable to retain the fuel in the fuel manifold and the fuel nozzle without recovering the fuel. According to the aspect of the present invention, since the first passage and the fourth passage on the fuel pump side are closed by closing the on-off valve, the piston does not move to the first port side even when the engine is stopped. Therefore, the fuel is not recovered and remains in the fuel manifold and the fuel nozzle, so that the engine can be quickly restarted. In addition, the versatility of the fuel supply system can be improved by switching the recovery operation on or off according to the length of the engine stop time.

[0020] Claims of the invention 6 According to the fuel supply system described in the above, the on-off valve and the selective switching valve are integrated into a three-way valve. This allows the above-mentioned effects of each valve to be achieved with a simple configuration. In addition, since there is no need to provide multiple valves in the passage, the space required for installing the valves can be saved and the passage can be shortened. This prevents the fuel supply system from becoming too heavy or too large. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic configuration diagram of a fuel supply system according to a first embodiment. [Diagram 2] FIG. 4 is a diagram showing an operation of the fuel supply system according to the first embodiment during fuel recovery. [Diagram 3] FIG. 7 is a schematic configuration diagram of a fuel supply system according to a second embodiment. [Figure 4] FIG. 11 is a schematic configuration diagram of a fuel supply system according to a third embodiment. [Diagram 5] FIG. 11 is a diagram showing an operation of the fuel supply system according to the third embodiment during fuel recovery. [Figure 6] FIG. 11 is a diagram showing the operation of the fuel supply system according to the third embodiment when the engine is stopped for a short period of time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] (First embodiment) (Fuel supply system) Fig. 1 is a schematic configuration diagram of a fuel supply system 1 according to a first embodiment. Fig. 1 is a diagram showing the operation when fuel is being supplied to a combustor of an engine (when the engine is operating). The fuel supply system 1 is a system for supplying fuel to a combustion chamber (not shown) of a gas turbine hybrid engine or a gas turbine engine (hereinafter, sometimes simply referred to as an engine) mounted on, for example, an aircraft (not shown). The fuel supply system 1 supplies fuel stored in a fuel tank 2 to a fuel nozzle 5 for supplying fuel to the combustion chamber, for example, when the engine is operating. Furthermore, the fuel supply system 1 is capable of recovering at least fuel remaining in the fuel nozzle 5 when the engine is stopped. The fuel supply system 1 includes the fuel tank 2, a fuel supply unit 7, and an ecology device 6.

[0024] The fuel tank 2 stores fuel. The fuel tank 2 is connected to the fuel pump 3 via a connecting pipe 8. That is, the fuel tank 2 is connected to one end of the connecting pipe 8, and the fuel pump 3 is connected to the other end of the connecting pipe 8. The fuel pump 3 is an electric pump that is driven by power from a battery (not shown), for example. The fuel pump 3 draws fuel from the fuel tank 2 and supplies the fuel to the ecological device 6 and the fuel supply unit 7.

[0025] The fuel supply unit 7 is connected to the fuel tank 2 (fuel pump 3) via an ecology device 6, which will be described in detail later. Fuel is supplied to the fuel supply unit 7 from the fuel tank 2. The fuel supply unit 7 supplies the fuel circulated from the fuel tank 2 to a combustion chamber of the engine. The fuel supply unit 7 has a fuel nozzle 5 and a fuel manifold 4.

[0026] At least a portion of the fuel nozzle 5 communicates with the combustion chamber, and injects and supplies fuel into the combustion chamber when the engine is operating. In this embodiment, a plurality of fuel nozzles 5 are provided. The fuel manifold 4 is disposed upstream of the fuel nozzles 5 in the fuel flow direction. The fuel manifold 4 supplies fuel from the fuel tank 2 to each of the plurality of fuel nozzles 5. The number of fuel manifolds 4 provided is smaller than the number of fuel nozzles 5. In this embodiment, one fuel manifold 4 is provided for each of the plurality of fuel nozzles 5. The fuel manifold 4 is formed in an annular shape. The fuel manifold 4 has an inlet portion 41 into which the fuel flows in, and a plurality of outlet portions 42 that respectively communicate with the plurality of fuel nozzles 5. The outlet portions 42 are provided, for example, lined up along the circumferential direction of the annular fuel manifold 4. The fuel flows out from the plurality of outlet portions 42, so that the fuel manifold 4 can simultaneously supply fuel to the plurality of fuel nozzles 5.

[0027] The ecology device 6 is provided between the fuel tank 2 and the fuel supply unit 7 in the fuel flow direction. The ecology device 6 supplies fuel to the fuel supply unit 7 when the engine is operating, and recovers fuel remaining in the fuel supply unit 7 when the engine is stopped. Specifically, the ecology device 6 has a cylinder 10, a first passage 11, a second passage 12, a third passage 13, a piston 14, and a biasing unit 15.

[0028] The cylinder 10 is formed with a space of a predetermined size inside. The size of the space inside the cylinder 10 will be described in detail later. The cylinder 10 has a first port 21 provided at an end and a second port 22 provided at an end opposite to the first port 21. The first port 21 communicates with the first passage 11. The second port 22 communicates with the second passage 12. In other words, the cylinder 10 is provided between the first passage 11 and the second passage 12.

[0029] The first passage 11 connects a first port 21 of the cylinder 10 and the fuel tank 2 (more specifically, the fuel pump 3). The first passage 11 is in communication with both the first port 21 of the cylinder 10 and the fuel pump 3. Therefore, fuel sucked from the fuel tank 2 by the fuel pump 3 flows through the first passage 11 and into the cylinder 10 from the first port 21. The second passage 12 connects the second port 22 of the cylinder 10 and the inlet portion 41 of the fuel manifold 4. The second passage 12 is in communication with the second port 22 of the cylinder 10 and the fuel manifold 4. Therefore, the fuel in the cylinder 10 flows through the second passage 12 into the fuel manifold 4.

[0030] The third passage 13 branches off from the first passage 11 and communicates with the second passage 12. In other words, the third passage 13 connects the first passage 11 and the second passage 12 without passing through the cylinder 10. A check valve 25 is provided in the third passage 13. The check valve 25 allows communication from the first passage 11 to the second passage 12 and prevents communication from the second passage 12 to the first passage 11.

[0031] The piston 14 is provided inside the cylinder 10. The piston 14 is configured to be able to slide inside the cylinder 10. The piston 14 divides the space inside the cylinder 10 into a first space 31 communicating with the first passage 11 and a second space 32 communicating with the second passage 12. The piston 14 blocks the flow of fuel between the first space 31 and the second space 32. That is, the first space 31 and the second space 32 are independent spaces sandwiching the piston 14. The piston 14 slides between a first position P1 (see FIG. 2) located on the first port 21 side and a second position P2 located on the second port 22 side from the first position P1. The first position P1 is a stop position of the piston 14 when the ecology device 6 collects the residual fuel in the fuel supply unit 7 when the engine is stopped. The second position P2 is a stop position of the piston 14 when the ecological device 6 supplies fuel from the fuel tank 2 to the fuel supply unit 7 during engine operation.

[0032] In this embodiment, the first position P1 is a position when the piston 14 abuts against an end of the cylinder 10 on the first port 21 side. That is, the first position P1 is set so that the volume A1 of the first space 31 becomes zero when the piston 14 is located at the first position P1. In addition, the second position P2 is a position closer to the second port 22 than the center of the cylinder 10 in the longitudinal direction of the cylinder 10 (the direction along the movement direction of the piston 14).

[0033] The biasing part 15 is provided inside the second space 32 of the cylinder 10. The biasing part 15 is, for example, a spring. The biasing part 15 connects the end of the cylinder 10 on the second port 22 side to the piston 14. The biasing part 15 biases the piston 14 from the second port 22 side toward the first port 21 side. The biasing part 15 (spring) is in a most compressed state when the piston 14 is in the second position P2, and in a most extended state when the piston 14 is in the first position P1.

[0034] (Cylinder volume) In the ecological device 6 configured as described above, the size of the volume of the cylinder 10 will be described in detail below. The volume of the cylinder 10 is equal to the sum of the volume A1 of the first space 31 and the volume A2 of the second space 32. The volume A1 of the first space 31 and the volume A2 of the second space 32 gradually change inversely proportional to each other due to the movement of the piston 14, but the volume of the entire cylinder 10 (i.e., the sum of the volume A1 of the first space 31 and the volume A2 of the second space 32) is, in principle, a constant value regardless of the position of the piston 14.

[0035] Here, when the engine is in operation, the piston 14 is located at the second position P2. The volume A1 of the first space 31 of the cylinder 10 at this time is called the first volume B1 during operation. In addition, when the engine is stopped, the total volume of the fuel that can remain in the fuel manifold 4 and the fuel nozzle 5 is defined as the required recovery volume D. The volume of the piston 14 is set so that the first volume B1 during operation is equal to or larger than the required recovery volume D (B1≧D). Furthermore, it is preferable that the volume of the piston 14 is as close as possible to the first volume B1 during operation and the required recovery volume D within a range that satisfies the above-mentioned condition B1≧D. In this embodiment, the volume of the cylinder 10 is set so that the first volume B1 during operation is equal to the required recovery volume D (B1=D).

[0036] (The biasing force of the biasing portion) Next, the magnitude of the biasing force of the biasing portion 15 provided in the second space 32 will be described. The above-mentioned first volume B1 at the time of operation is the volume A1 of the first space 31 when the piston 14 is located at the second position P2. The second position P2 is determined by the balance between the fuel pressure from the fuel tank 2 flowing into the first space 31 and the biasing force of the biasing portion 15 when the engine is operating. In other words, the first volume B1 at the time of operation is equal to the volume A1 of the first space 31 when the pressure difference between the first space 31 and the second space 32 and the biasing force of the biasing portion 15 are balanced when the engine is operating. The biasing force of the biasing portion 15 is set to a magnitude such that the first volume B1 at the time of operation is larger than the required collection volume D. In this embodiment, the biasing force of the biasing portion 15 is set so that the first volume B1 at the time of operation is equal to or larger than the required collection volume D.

[0037] (Fuel supply system operation) Next, a description will be given of the operation of the fuel supply system 1. First, a description will be given of the operation when fuel is supplied from the fuel tank 2 to the fuel supply unit 7 via the ecology device 6 (when the engine is operating). As shown in FIG. 1, when the engine is in operation, first, the fuel pump 3 is driven to cause fuel to flow from the fuel tank 2 into the first passage 11. Part of the fuel that has flowed into the first passage 11 flows from the first port 21 into the first space 31 of the cylinder 10, and the fuel pressure moves the piston 14 toward the second port 22. When the piston 14 reaches the first position P1 where the fuel pressure and the biasing force of the biasing portion 15 are balanced, the movement of the piston 14 almost stops, and the inflow of fuel into the first space 31 stops. After the inflow into the first space 31 stops, the pressure of the check valve 25 increases to the set pressure, and at the same time, the remaining part of the fuel in the first passage 11 flows through the third passage 13 and flows into the second passage 12. Then, the fuel flows from the second passage 12 through the inlet portion 41 of the fuel manifold 4 and is filled into the fuel manifold 4. Furthermore, the fuel in the fuel manifold 4 is supplied from the outlet portion 42 to each fuel nozzle 5, and is injected from the tip of each fuel nozzle 5 into the combustion chamber.

[0038] FIG. 2 is a diagram showing the operation of the fuel supply system 1 according to the first embodiment during fuel recovery. With reference to FIG. 2, the operation when the ecology device 6 recovers the fuel remaining in the fuel supply section 7 (when the engine is stopped) will be described. 2, when the engine is stopped from a running state, the operation of the fuel pump 3 is stopped and the supply of fuel from the fuel tank 2 is stopped. When the fuel pump 3 is stopped, the fuel pressure decreases, and as a result, the biasing force of the biasing portion 15 becomes greater than the fuel pressure. In other words, the total pressure of the pressure in the second space 32 and the biasing force becomes greater than the pressure in the first space 31. As a result, the biasing force moves the piston 14 from the second position P2 toward the first position P1 on the first port 21 side.

[0039] When the piston 14 moves toward the first port 21, the volume A2 of the second space 32 increases, causing a negative pressure inside the second space 32. Here, a check valve 25 is provided in the third passage 13, and prevents fuel from flowing from the second passage 12 to the first passage 11. Therefore, when the second space 32 becomes negative pressure, the remaining fuel in the fuel manifold 4 and the fuel nozzle 5 flows into the second space 32. As a result, the remaining fuel in the fuel supply unit 7 is collected by the ecology device 6.

[0040] At this time, the volume of fuel recovered by the ecology device 6 is equal to the volume A2 of the second space 32 that has increased as a result of the piston 14 moving from the second position P2 to the first position P1. Since the first position P1 is a position where the volume A1 of the first space 31 is zero, the increased volume A2 of the second space 32 is equal to the volume A1 of the first space 31 when the engine is operating (first volume B1 during operation). In this embodiment, the first volume B1 during operation is equal to the total volume of the fuel manifold 4 and the fuel nozzle 5. Therefore, the ecology device 6 can recover almost all of the fuel in the fuel manifold 4 and the fuel nozzle 5.

[0041] (Action, effect) Next, the operation and effects of the above-mentioned fuel supply system 1 will be described. According to the fuel supply system 1 of this embodiment, an ecology device 6 is provided between the fuel tank 2 and the fuel manifold 4, and the ecology device 6 includes a cylinder 10 having a first passage 11, a second passage 12, a first port 21 and a second port 22, a piston 14, a biasing portion 15, and a third passage 13 having a check valve 25. The piston 14 divides the space inside the cylinder 10 into a first space 31 and a second space 32. When the engine is operating, fuel supplied from the fuel tank 2 flows through the third passage 13 and is supplied to the fuel manifold 4, and the piston 14 moves toward the second port 22 side due to the pressure from the fuel tank 2. The volume A1 of the first space 31 at this time is set to the first volume B1 during operation. On the other hand, when the engine is stopped, the pressure from the fuel tank 2 decreases, and the piston 14 moves toward the first port 21 side. As a result, the second space 32 becomes negative pressure, and the residual fuel in the fuel nozzle 5 connected to the second space 32 of the cylinder 10 via the second port 22 and the second passage 12 is collected into the second space 32 of the cylinder 10. Therefore, the residual fuel can be collected when the engine is stopped, and coking of the fuel nozzle 5 can be suppressed.

[0042] The first volume B1 during operation, which is the volume A1 of the first space 31 during engine operation, is larger than the required recovery volume D, which is the total of the fuel in the fuel manifold 4 and the fuel nozzle 5. Here, the volume of the residual fuel that can be recovered by the ecology device 6 is equal to the volume A2 of the second space 32 that increases with the movement of the piston 14. In this embodiment of the present invention, the volume of the cylinder 10 is equal to the sum of the volume A1 of the first space 31 and the volume A2 of the second space 32 partitioned by the piston 14. Therefore, the volume A2 of the second space 32 that increases with the movement of the piston 14, i.e., the volume of the residual fuel that can be recovered, is equal to the volume A1 of the first space 31 that decreases with the movement of the piston 14. According to this embodiment of the present invention, since the first volume B1 during operation is larger than the required recovery volume D, the piston 14 moves to narrow the first space 31 when the engine is stopped, so that the residual fuel can be reliably recovered. In addition, the size of the first space 31 can be set according to the volume of the residual fuel. This optimizes the volume of the cylinder 10 and prevents the cylinder 10 from becoming excessively large. Furthermore, since the recovery function can be achieved by a single cylinder 10 and piston 14, the configuration can be simplified and made smaller and lighter than in the prior art in which a muscle valve is provided in addition to the cylinder 10 and piston 14.

[0043] Furthermore, the recovered residual fuel is contained only in the second space 32, and does not flow into the first space 31 or the first passage 11. As a result, even if combustion gas is mixed in when the residual fuel is being recovered, the combustion gas can be prevented from entering the supply flow path on the fuel tank 2 side. This makes it possible to minimize the area with which the combustion gas comes into contact, thereby preventing oxidation, etc. caused by the combustion gas and preventing deterioration of parts. Therefore, it is possible to provide a fuel supply system 1 that can prevent the size of the cylinder 10 from increasing by optimizing the volume of the cylinder 10 and also suppress deterioration of the components.

[0044] The first operating volume B1 is determined by the balance between the pressure difference between the first space 31 and the second space 32 and the biasing force of the biasing unit 15 when the engine is operating. The magnitude of the biasing force of the biasing unit 15 is set so that the first operating volume B1 is larger than the required collection volume D. By setting the biasing force of the biasing unit 15 in this manner, a desired first operating volume B1 can be automatically ensured by the balance between the two forces when the engine is operating. Therefore, there is no need to provide a control system or the like for electrically controlling the position of the piston 14, and the configuration of the fuel supply system 1 can be simplified.

[0045] The first volume B1 during operation is set to be equal in size to the required recovery volume D. This allows the remaining fuel to be reliably recovered while further optimizing the volume of the cylinder 10. This allows the size of the cylinder 10 to be minimized, and the fuel supply system 1 to be further reduced in size, weight, and cost.

[0046] Second embodiment Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic diagram of a fuel supply system 201 according to the second embodiment. The configurations of the fuel tank 2 and the fuel supply unit 7 in the second embodiment are the same as those in the first embodiment. For this reason, FIG. 3 illustrates only the ecology device 206, and the fuel tank 2 and the fuel supply unit 7 are not illustrated. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. This embodiment differs from the first embodiment described above in that the ecology device 206 further includes a stopper 250.

[0047] 3, in this embodiment, an ecological device 206 has a cylinder 10, a first passage 11, a second passage 12, a third passage 13, a piston 14, a biasing portion 215, and a stopper 250. The configurations of the cylinder 10, the first passage 11, the second passage 12, the third passage 13, and the piston 14 are similar to those in the first embodiment, and therefore description thereof will be omitted. The biasing force of the biasing portion 215 in the second embodiment is equivalent to the biasing force of the biasing portion 15 in the first embodiment.

[0048] The stopper 250 is provided in the second space 32 of the cylinder 10. The stopper 250 is provided closer to the second port 22 than the piston 14, and limits the movement of the piston 14 toward the second port 22. The stopper 250 is formed, for example, so as to protrude from the inner wall of the cylinder 10 toward the inside of the cylinder 10. Note that the stopper 250 may be configured as a separate part from the cylinder 10, or may be formed integrally with the inner wall of the cylinder 10.

[0049] When the engine is operating, the piston 14 abuts against the stopper 250. The volume A1 of the first space 31 of the cylinder 10 when the piston 14 abuts against the stopper 250 is set as a first volume B1 during operation. The stopper 250 is provided at a position such that the first volume B1 during operation is larger than the required recovery volume D (see FIG. 1). Here, the biasing force of the biasing portion 215 is set at the minimum pressure value among the engine conditions when the engine is stopped and fuel is recovered, so that the piston 14 can be reliably brought into contact with the stopper 250 during the engine operation.

[0050] According to this embodiment, when the engine is operating, the piston 14 abuts against the stopper 250 provided in the second space 32. The stopper 250 is provided at a position such that the volume A1 (first volume B1 during operation) of the first space 31 of the cylinder 10 becomes larger than the required recovery volume D when the piston 14 abuts against the stopper 250. This makes it possible to stably ensure a desired first volume B1 during operation during engine operation without being affected by pressure fluctuations in the fuel tank 2. Therefore, all of the remaining fuel can be more reliably recovered when the engine is stopped.

[0051] Third embodiment Next, a third embodiment according to the present invention will be described. FIG. 4 is a schematic diagram of a fuel supply system 301 according to the third embodiment. FIG. 5 is a diagram showing the operation of the fuel supply system 301 according to the third embodiment when collecting fuel. FIG. 6 is a diagram showing the operation of the fuel supply system 301 according to the third embodiment when the engine is stopped for a short time. In the following description, the same components as those in the first embodiment described above are given the same reference numerals and the description is omitted as appropriate. This embodiment differs from the first embodiment described above in that the fuel supply system 301 further includes a fourth passage 314 and a three-way valve 330, and in that an operation different from that during the normal engine stop described above is performed during the engine stop for a short time.

[0052] As shown in FIG. 4, in this embodiment, a fuel supply system 301 further includes a fourth passage 314 and a three-way valve 330 in addition to the configuration of the first embodiment described above. The fourth passage 314 branches off from the first passage 11 on the fuel upstream side of the connection point of the first passage 11 with the third passage 13 and is connected to the fuel tank 2. One end of the fourth passage 314 is connected to the first passage 11. The other end of the fourth passage 314 is connected to the fuel tank 2. The fourth passage 314 is used as a flow path for the fuel to flow during fuel recovery. The fuel in the first passage 11 flows into the fourth passage 314. In the following description, the part of the first passage 11 upstream of the connection point with the fourth passage 314 may be referred to as a pump-side first passage 311A. The part of the first passage 11 downstream of the connection point with the fourth passage 314 may be referred to as a cylinder-side first passage 311B.

[0053] The three-way valve 330 is provided at a connection portion between the first passage 11 and the fourth passage 314. The three-way valve 330 is configured to be able to switch at least between the first passage 11 (the pump-side first passage 311A) and the fourth passage 314. The three-way valve 330 has a first valve 331 (an open / close valve in claims), a second valve 332 (a selective switching valve in claims), and a third valve 333 (a selective switching valve in claims). The first valve 331 controls the flow of fuel in the cylinder-side first passage 311B. The second valve 332 controls the flow of fuel in the pump-side first passage 311A. The third valve 333 controls the flow of fuel in the fourth passage 314. The first to third valves 331, 332, 333 are integrally formed as the three-way valve 330. The three-way valve 330 is, for example, a mechanical three-way valve that can switch in a predetermined combination between the open and closed states of the valves 331, 332, and 333. Note that the three-way valve 330 may be, for example, an electromagnetic three-way valve that can independently control the open and closed states of the valves 331, 332, and 333.

[0054] As shown in FIG. 4, when fuel is supplied from the fuel tank 2 to the fuel supply unit 7 via the ecology device 6 (when the engine is operating), the three-way valve 330 is controlled so that the fuel flows through the first passage 11 and is supplied to the ecology device 6. Specifically, when the engine is operating, the first valve 331 and the second valve 332 of the three-way valve 330 are opened, and the third valve 333 is closed. As a result, the pump-side first passage 311A ​​and the cylinder-side first passage 311B are connected to each other. In addition, the flow of fuel from the first passage 11 to the fourth passage 314 is blocked. As a result, similar to the first embodiment, the fuel from the fuel tank 2 flows through the first passage 11, the third passage 13, and the second passage 12 in this order and is supplied to the fuel supply unit 7.

[0055] Next, as shown in FIG. 5, when the ecology device 6 recovers the fuel remaining in the fuel supply unit 7 (when the engine is normally stopped), the three-way valve 330 is controlled so that the fuel recovered by the ecology device 6 flows through the fourth passage 314 and returns to the fuel tank 2. Specifically, when the engine is normally stopped, the first valve 331 and the third valve 333 of the three-way valve 330 are opened, and the second valve 332 is closed. This allows the cylinder-side first passage 311B to communicate with the fourth passage 314. Also, the flow of fuel to the pump-side first passage 311A ​​is blocked. As a result, the fuel filled in the first space 31 flows through the cylinder-side first passage 311B and the fourth passage 314 in this order, and is returned to the fuel tank 2.

[0056] Next, as shown in FIG. 6, when the engine is stopped for a short time due to some factor from a state in which the engine is operating (when the engine is stopped for a short time), the three-way valve 330 is controlled so that the fuel is left in the fuel supply unit 7 (is not recovered by the eco-friendly device 6) in order to quickly restart the engine. Specifically, when the engine is stopped for a short time, the second valve 332 and the third valve 333 of the three-way valve 330 are opened, and the first valve 331 is closed. As a result, the fuel cannot flow from the cylinder-side first passage 311B to either the pump-side first passage 311A ​​or the fourth passage 314. In this case, even if the driving of the fuel pump 3 is stopped due to the engine stopping, the fuel in the cylinder-side first passage 311B is not discharged, so the fuel pressure in the first space 31 is maintained high. Therefore, the volume A2 of the second space 32 does not change, so the fuel is not recovered and remains in the fuel supply unit 7. When restarting the engine, by controlling the three-way valve 330 to open the first valve 331 and the second valve 332 and close the third valve 333 in the same manner as during engine operation described above, the engine can be started quickly using the fuel remaining in the fuel supply unit 7.

[0057] According to this embodiment, the fuel supply system 301 includes a fourth passage 314 and a three-way valve 330 (a selective switching valve and an on-off valve in claims). The three-way valve 330 is controlled so that the fuel flows through the first passage 11 (the pump-side first passage 311A) when the engine is operating, and the fuel flows through the fourth passage 314 when the engine is stopped. In this way, the flow path through which the fuel flows is different when the engine is operating (when the fuel is being supplied) and when the engine is stopped (when the fuel is being recovered). Therefore, even when a one-way fuel pump 3 is used, for example, the supply and recovery of the fuel can be performed without wearing out the pump. In addition, since the supply path and the recovery path of the fuel are different, it is easy to manage the supply amount and the recovery amount of the fuel. Therefore, the supply amount of the fuel from the fuel tank 2 to the fuel nozzle 5 can be more precisely controlled.

[0058] The multiple valves (first valve 331, second valve 332, and third valve 333) are integrated into a three-way valve 330. This allows the above-mentioned effects of the valves 331, 332, and 333 to be achieved with a simple configuration. In addition, since there is no need to provide multiple valves on the passage, the space required for installing the valves can be saved and the passage can be shortened. This prevents the fuel supply system 1 from becoming too heavy or too large.

[0059] A three-way valve 330 is provided in the first passage 11, and when the engine is stopped for a short time, a first valve 331 of the three-way valve 330 is closed. Here, for example, the engine may misfire unintentionally, and the engine may be stopped for a short time. In such a case, since the engine needs to be restarted immediately, it is desirable to retain the fuel in the fuel manifold 4 and the fuel nozzle 5 without recovering the fuel. According to the aspect of the present invention, by closing the first valve 331, the pressure on the fuel tank 2 side is maintained in a high state, so that the piston 14 does not move to the first port 21 side even when the engine is stopped. Therefore, the fuel is not recovered and remains in the fuel manifold 4 and the fuel nozzle 5, so that the engine can be quickly restarted. In addition, by switching between the presence and absence of the recovery operation according to the length of the engine stop time, the versatility of the fuel supply system 1 can be improved.

[0060] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the required recovery volume D is the sum of the volume of the fuel manifold 4 and the volume of the fuel nozzle 5, but is not limited to this. The required recovery volume D may be at least as large as the volume of the fuel nozzle 5. That is, the volume of the cylinder 10 of the ecology device 6 may be set so that at least the fuel in the fuel nozzle 5 can be recovered when the engine is stopped. More specifically, the required recovery volume D may be at least as large as the volume of the fuel nozzle 5 and at most the total volume of the fuel manifold 4 and the fuel nozzle 5. However, the configuration of this embodiment in which the required recovery volume D is the total volume of the fuel manifold 4 and the fuel nozzle 5 is advantageous in that the fuel in the fuel nozzle 5 can be recovered more reliably while suppressing an increase in size of the cylinder 10.

[0061] The ecological device 6 may include, for example, a separate housing or case that holds the cylinder 10 and in which the first to third passages 11, 12, and 13 are formed. In the third embodiment, the first to third valves 331, 332, 333 may be provided separately in each flow path (in this embodiment, the first cylinder-side passage 311B, the first pump-side passage 311A, and the fourth passage 314). However, the configuration of this embodiment in which the three valves 331, 332, 333 are integrated into the three-way valve 330 is advantageous in that it reduces the number of parts and simplifies the configuration.

[0062] In the first and second embodiments, a valve mechanism corresponding to the first valve 331 shown in the third embodiment may be provided. In this case, the valve mechanism may be provided integrally with the fuel pump 3, for example. The valve mechanism may be provided at any position downstream of the fuel pump 3 and upstream of the connection point between the first passage 11 and the third passage 13.

[0063] A relief valve may be used as the check valve in the claims. In the third embodiment described above, when the engine is stopped for a short time, the second valve 332 and the third valve 333 of the three-way valve 330 are opened and the first valve 331 is closed, but this is not limited to the above. The second valve 332 and the third valve 333 of the three-way valve 330 may be closed and the first valve 331 may be opened. In this case, by opening the second valve 332 at the time of starting the engine, the engine can be started quickly using the remaining fuel.

[0064] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described embodiments may be combined as appropriate. [Explanation of symbols]

[0065] 1,201,301 Fuel supply system 2 Fuel tanks 4 Fuel Manifold 5 Fuel Nozzle 6,206,306 Ecological Equipment 10 Cylinders 11 First aisle 12 Second aisle 13 Third aisle 14 Piston 15,215 Actuator 21 First Port 22 Second Port 25 Check valve 31 First space 32 Second space 250 Stopper 314 Fourth aisle 330 Three-way valve 331 First valve (on-off valve) 332 Second valve (selective switching valve) 333 Third valve (selective switching valve) A1 Volume of the first space A2 Volume of the second space B1 First volume during operation D Required collection volume

Claims

1. 1. A fuel supply system for a gas turbine engine, comprising: A fuel tank; a fuel manifold that supplies fuel from the fuel tank to a fuel nozzle; an ecology device provided between the fuel tank and the fuel manifold and configured to collect fuel from the fuel manifold; Equipped with The ecological device comprises: a first passage connected to the fuel tank; a second passage connected to the fuel manifold; a cylinder provided between the first passage and the second passage, the cylinder having a first port communicating with the first passage and a second port communicating with the second passage; a piston that divides an internal space of the cylinder into a first space communicating with the first passage and a second space communicating with the second passage and that slides inside the cylinder; a biasing portion that biases the piston from the second port side toward the first port side; a third passage branching from the first passage and communicating with the second passage; a check valve provided in the third passage and configured to prevent communication from the second passage to the first passage; a fourth passage branching from the first passage and connected to the fuel tank; a selective switching valve capable of switching between the first passage and the fourth passage; Equipped with The volume of the cylinder is equal to the sum of the volume of the first space and the volume of the second space, a volume of the first space of the cylinder during engine operation of the gas turbine engine is defined as an operating first volume; When the gas turbine engine is stopped, the total volume of the fuel manifold and the fuel nozzle is defined as a required recovery volume, the first operating volume is greater than the required recovery volume; When the engine is operating, the selective switching valve is controlled so that the fuel flows through the first passage and is supplied to the ecology device, a selective switching valve being controlled so that, when the engine is stopped, the fuel filled in the first space flows through the fourth passage and returns to the fuel tank.

2. the first operating volume is determined by a balance between a pressure difference between the first space and the second space and the biasing force of the biasing portion during operation of the engine, 2. The fuel supply system according to claim 1, wherein the biasing force of the biasing portion is set to a magnitude such that the first volume during operation is larger than the required recovery volume.

3. a stopper provided in the second space to limit movement of the piston toward the second port; When the engine is operating, the piston abuts against the stopper, a volume of the first space of the cylinder when the piston abuts against the stopper is defined as the first actuation volume; 2. The fuel supply system according to claim 1, wherein the stopper is disposed at a position such that the first volume during operation is greater than the required recovery volume.

4. 4. The fuel supply system according to claim 1, wherein the first operating volume is equal to the required recovery volume.

5. an on-off valve provided in the first passage, 5. The fuel supply system according to claim 1, wherein the on-off valve is closed when the engine is stopped for a short period of time.

6. 6. The fuel supply system according to claim 5, wherein a three-way valve in which the on-off valve and the selective changeover valve are integrated is provided at a connecting portion between the first passage and the fourth passage.

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