Fuel supply device

Abstract

To improve filling performance of fuel in a pump chamber during initial filling of fuel in the empty pump chamber of a fuel pump.SOLUTION: A fuel supply device 10 includes: an upstream side supply line 14 connecting a fuel tank 12 that stores fuel and a fuel pump 20; and a downstream side supply line 30 connecting the fuel pump 20 and an engine 32. An upstream side bypass line 50 that is branched from the upstream side supply line 14 and merges with a pump chamber of the fuel pump 20 is provided. A check valve 60 that inhibits a backflow is provided in the upstream side bypass line 50.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a fuel supply device. [Background technology]

[0002] A conventional fuel supply device (fuel pump) is disclosed, for example, in Patent Document 1. The fuel pump transmits the driving force of a motor to a pump section via a magnetic coupling, rotating the impeller of the pump section, thereby drawing up fuel from a fuel tank and supplying it to a fuel-requiring device such as an engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-269275 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, fuel in a fuel tank is drawn up by a fuel pump through an upstream supply line and supplied to a fuel demanding device through a downstream supply line. Therefore, when initially filling a pump chamber with fuel when the pump is empty, it takes a long time for the air (corresponding to "vapor" in this specification) in the pump chamber to be discharged and for the pump chamber to become liquid-tight. In other words, there is a problem in that the pump chamber is not easily filled with fuel.

[0005] The problem to be solved by the technique disclosed in this specification is to improve the ability to fill a pump chamber with fuel when initially filling an empty pump chamber with fuel. [Means for solving the problem]

[0006] In order to solve the above problems, the technology disclosed in this specification takes the following measures.

[0007] The first means is a fuel supply device that includes an upstream supply line that connects a fuel tank that stores fuel to a fuel pump, and a downstream supply line that connects the fuel pump to a fuel demanding device, and that is provided with an upstream bypass line that branches off from the upstream supply line and joins the pump chamber of the fuel pump.

[0008] According to the first aspect, when the pump chamber of the fuel pump is initially filled with fuel while it is empty, fuel flows into the pump chamber from both the upstream supply line and the upstream bypass line. This improves vapor discharge from the pump chamber. Therefore, it is possible to improve the efficiency of filling the pump chamber with fuel when the pump chamber is initially filled with fuel.

[0009] The second means is the fuel supply device of the first means, wherein the upstream bypass line is provided with a check valve for preventing backflow.

[0010] According to the second means, the check valve can prevent backflow in the upstream bypass line, thereby suppressing a decrease in the output of the fuel pump.

[0011] The third means is the fuel supply device of the first means, which is provided with a pressure sensor that detects the fuel pressure in the downstream supply line, and a solenoid valve that closes based on the detection result of the pressure sensor to prevent backflow in the upstream bypass line.

[0012] According to the third aspect, the solenoid valve closes based on the detection result of the pressure sensor, thereby preventing backflow in the upstream bypass line. This makes it possible to suppress a decrease in the output of the fuel pump. Furthermore, when the pump output decreases due to cavitation of the fuel pump, the solenoid valve opens to discharge vapor from the pump chamber.

[0013] The fourth means is a fuel supply device including an upstream supply line that connects a fuel tank that stores fuel to a fuel pump, and a downstream supply line that connects the fuel pump to a fuel demanding device, and further including a downstream bypass line that branches off from a pump chamber of the fuel pump and joins the downstream supply line.

[0014] According to the fourth aspect, when the pump chamber of the fuel pump is initially filled with fuel while it is empty, fuel flows into the pump chamber, causing vapor in the pump chamber to be discharged from both the downstream supply line and the downstream bypass line. This improves vapor discharge from the pump chamber. Therefore, it is possible to improve the efficiency of filling the pump chamber with fuel when the pump chamber is initially filled with fuel.

[0015] A fifth means is the fuel supply device of the fourth means, wherein the downstream bypass line is provided with a check valve for preventing backflow.

[0016] According to the fifth aspect, the check valve can prevent backflow in the downstream bypass line, thereby suppressing a decrease in the output of the fuel pump.

[0017] A sixth means is the fuel supply device of the fourth means, which is provided with a pressure sensor that detects the fuel pressure in the downstream supply line, and a solenoid valve that closes based on the detection result of the pressure sensor to prevent backflow in the downstream bypass line.

[0018] According to the sixth aspect, the solenoid valve closes based on the detection result of the pressure sensor, thereby preventing backflow in the downstream bypass line. This makes it possible to suppress a decrease in the output of the fuel pump. Furthermore, when the pump output decreases due to cavitation of the fuel pump, the solenoid valve opens to discharge vapor from the pump chamber.

[0019] A seventh means is a fuel supply device according to the first or fourth means, wherein the fuel is a compressed fuel such as ammonia liquefied fuel, and is supplied to the pump chamber by the ejection pressure from the fuel tank.

[0020] According to the seventh means, the compressed fuel can be filled into the empty pump chamber of the fuel pump by the ejection pressure from the fuel tank. [Effects of the Invention]

[0021] According to the technique disclosed in this specification, it is possible to improve the efficiency of filling the pump chamber with fuel when initially filling the pump chamber with fuel when the pump chamber is empty. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a configuration diagram showing a fuel supply device according to a first embodiment. [Figure 2] FIG. 2 is a side view showing a fuel pump with a part cut away. [Figure 3] FIG. [Figure 4] FIG. 10 is a configuration diagram showing a fuel supply device according to a second embodiment. [Figure 5] FIG. 10 is a configuration diagram showing a fuel supply device according to a third embodiment. [Figure 6] FIG. [Figure 7] FIG. 10 is a configuration diagram showing a fuel supply device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments for carrying out the techniques disclosed in this specification will be described with reference to the drawings.

[0024] [Embodiment 1] A fuel supply device according to this embodiment will be described. FIG. 1 is a configuration diagram showing the fuel supply device. As shown in FIG. 1, a fuel supply device 10 supplies fuel stored in a fuel tank 12 to a combustion chamber 33 of an engine 32 by an in-line fuel pump 20. The fuel is, for example, a compressed fuel such as ammonia liquefied fuel (liquefied ammonia). The engine 32 corresponds to the "fuel demanding device" referred to in this specification.

[0025] The fuel supply device 10 includes an upstream supply line 14 that connects a fuel tank 12 and a fuel pump 20, and a downstream supply line 30 that connects the fuel pump 20 and a combustion chamber 33 of an engine 32. A shutoff valve 15 that functions as a main valve for the fuel tank 12 is provided midway along the upstream supply line 14. The shutoff valve 15 is controlled to open and close by an electronic control unit (hereinafter referred to as ECU) 40 of the engine 32. The ECU 40 controls the shutoff valve 15 and the fuel pump 20 (more specifically, a pump section 21, which will be described later) based on a control program previously stored in an internal memory. The ECU 40 corresponds to the "control means" as referred to in this specification.

[0026] (Fuel Pump 20) Fig. 2 is a partially cutaway side view of fuel pump 20. As shown in Fig. 2, fuel pump 20 is an electric pump with an integrated motor that includes a Westco-type (impeller-type, cascade-type, etc.) pump section 21 that draws in fuel, pressurizes it, and discharges it, a motor section 26 that drives pump section 21, and a magnetic coupling section 28 that transmits the power of motor section 26 to pump section 21.

[0027] The magnetic coupling unit 28 includes an outer member 28a having an outer magnet a1, an inner member 28b having an inner magnet b1, and a partition wall 28c that separates the two coupling members 28a, 28b. The outer member 28a is connected to an output shaft 26a of the motor unit 26. The inner member 28b is connected to a pump shaft 29 of the pump unit 21. The partition wall 28c prevents fuel from entering the interior of the motor unit 26 from the pump unit 21. The pump housing 22 of the pump unit 21 is connected to a motor housing 27 of the motor unit 26 via the partition wall 28c.

[0028] A pump chamber 23 is formed within the pump housing 22 of the pump section 21. An impeller 24 is rotatably disposed within the pump chamber 23. The impeller 24 is connected to an inner member 28b via a pump shaft 29. A group of grooves aligned in the circumferential direction is formed on the outer periphery of the front and back surfaces of the impeller 24. The recesses on the front and back surfaces are connected to each other. A pump flow path 23a is formed on the outer periphery of the pump chamber 23, corresponding to the group of grooves on the front and back surfaces of the impeller 24 and having a C-shape in the circumferential direction. The pump housing 22 is formed with a fuel intake port 22a that connects the starting end of the pump flow path 23a to the outside, and a fuel discharge port 22b that connects the terminal end of the pump flow path 23a to the outside. The downstream end of the upstream supply line 14 is connected to the fuel intake port 22a. The upstream end of the downstream supply line 30 is connected to the fuel discharge port 22b.

[0029] When the motor unit 26 is driven, the impeller 24 of the pump unit 21 is rotated via the magnetic coupling unit 28, causing fuel in the fuel tank 12 (see FIG. 1) to be drawn into the pump flow path 23a from the fuel intake port 22a via the upstream supply line 14 and pressurized. The fuel is then discharged from the fuel discharge port 22b. The fuel discharged from the fuel discharge port 22b is then supplied to the combustion chamber 33 (see FIG. 1) of the engine 32 via the downstream supply line 30.

[0030] (Characteristic configuration of embodiment 1) 1, a branch portion 14a is provided midway along the upstream supply line 14. A communication port 22c that connects the pump chamber 23 to the outside is provided in a pump housing 22 (see FIG. 2) of the fuel pump 20. The branch portion 14a of the upstream supply line 14 and the communication port 22c of the fuel pump 20 are connected via an upstream bypass line 50 (more specifically, a downstream line portion 50b).

[0031] A check valve 60 that prevents backflow is provided in the upstream bypass line 50. The check valve 60 allows fuel to flow (forward flow) from the upstream supply line 14 to the fuel pump 20, and blocks (prevents) fuel from flowing in the opposite direction (backflow). In the upstream bypass line 50, the portion upstream of the check valve 60 is referred to as an upstream line section 50a, and the portion downstream of the check valve 60 is referred to as a downstream line section 50b. FIG. 3 is a cross-sectional view showing the check valve 60.

[0032] The check valve 60 includes a valve housing 61, a valve element 62, and a spring 63. A hollow cylindrical valve chamber 64 is concentrically formed within the valve housing 61. A cylindrical valve seat 65 is concentrically formed at one end (the upper end in FIG. 3) of the valve housing 61. A tapered seat portion 65a that gradually reduces in diameter toward the top is formed at the tip (the lower end in FIG. 3) of the valve seat 65. The hollow portion of the valve seat 65 serves as an inlet 61a. An outlet 61b is eccentrically formed at the other end (the lower end in FIG. 3) of the valve housing 61. The downstream end of the upstream line portion 50a is connected to the inlet 61a. The upstream end of the downstream line portion 50b is connected to the outlet 61b.

[0033] The valve element 62 is a ball valve, and is provided so as to be movable in the axial direction (up and down in FIG. 3) within the valve chamber 64. The valve element 62 seats on and releases from a seat portion 65a of a valve seat 65. The spring 63 is a coil spring, and constantly biases the valve element 62 in the opening direction (downward in FIG. 3).

[0034] When the fuel pressure in the downstream line portion 50b is lower than the elastic force of the spring 63, the valve element 62 of the check valve 60 is opened by the elastic force of the spring 63 (see solid line 62 in FIG. 3). This allows forward flow through the upstream bypass line 50. When the fuel pressure in the downstream line portion 50b becomes higher than the elastic force of the spring 63, the valve element 62 is seated on a seat portion 65a of a valve seat 65 against the elastic force of the spring 63, thereby closing (see two-dot chain line 62 in FIG. 3). This prevents reverse flow through the upstream bypass line 50.

[0035] (Function of the fuel supply device 10) Assume now that the fuel supply flow path from the fuel tank 12 to the engine 32 is empty. The fuel supply flow path includes the upstream supply line 14, the downstream supply line 30, the flow path of the pump section 21 of the fuel pump 20, and the upstream bypass line 50. Unless otherwise specified, it is assumed that the ECU 40 controls the shutoff valve 15 and the fuel pump 20.

[0036] In this state, when the ignition switch of the engine 32 is turned on, the shutoff valve 15 is opened. Then, the compressed fuel in the fuel tank 12 is supplied to the combustion chamber 33 of the engine 32 through the upstream supply line 14, the fuel pump 20, and the downstream supply line 30 by the ejection pressure from the fuel tank 12. This fuel flow causes vapor (air) in the upstream supply line 14, the fuel pump 20, and the downstream supply line 30 to be discharged into the combustion chamber 33 of the engine 32.

[0037] At this time, a portion of the fuel flowing through the upstream supply line 14 flows into the pump chamber 23 via the upstream bypass line 50. That is, fuel flows into the pump chamber 23 from both the upstream supply line 14 and the upstream bypass line 50. At this time, the check valve 60 is in an open state (see solid line 62 in FIG. 3).

[0038] This allows the empty pump chamber 23 of the fuel pump 20 to be filled with fuel quickly, thereby improving the vapor discharge performance from the pump chamber 23. The fuel from the pump chamber 23 is then supplied to the combustion chamber 33 of the engine 32 from the fuel discharge port 22b via the downstream supply line 30.

[0039] Furthermore, the fuel pump 20 is driven after a predetermined time has elapsed since the ignition switch was turned on. Here, the predetermined time is defined as the time required from the time the ignition switch was turned on until the empty pump chamber 23 of the fuel pump 20 was completely filled with fuel plus a time α. The time from the time the ignition switch was turned on until the start of driving the fuel pump 20 corresponds to the initial fuel filling time (initial filling).

[0040] When the fuel pump 20 is driven, compressed fuel in the fuel tank 12 is drawn into the pump chamber 23 of the fuel pump 20 via the upstream supply line 14 and the upstream bypass line 50, where it is pressurized. The compressed fuel is then supplied from the fuel discharge port 22b through the downstream supply line 30 to the combustion chamber 33 of the engine 32, where it is burned. When the fuel pressure in the downstream line portion 50b becomes higher than the fuel pressure in the upstream line portion 50a, the valve element 62 closes (see the two-dot chain line 62 in FIG. 3 ). This prevents backflow in the upstream bypass line 50.

[0041] (Advantages of the characteristic configuration of embodiment 1) According to the first embodiment, when the pump chamber 23 of the fuel pump 20 is initially filled with fuel while the fuel pump 20 is empty, compressed fuel flows into the pump chamber 23 from both the upstream supply line 14 and the upstream bypass line 50. This improves the vapor discharge efficiency from the pump chamber 23. Therefore, the efficiency of filling the pump chamber 23 with fuel during the initial filling of the pump chamber 23 can be improved. In other words, the time required to fill the pump chamber 23 with fuel can be shortened.

[0042] Furthermore, the check valve 60 can prevent backflow in the upstream bypass line 50, thereby suppressing a decrease in the output of the fuel pump 20. The check valve 60 may be of a type in which the valve element 62 opens under its own weight.

[0043] In addition, compressed fuel can be filled into the empty pump chamber 23 of the fuel pump 20 by the ejection pressure from the fuel tank 12.

[0044] [Embodiment 2] This embodiment is a modification of the first embodiment (see FIG. 1), so the modifications will be described, and the same parts as those in the first embodiment will be assigned the same reference numerals and will not be described again. FIG. 4 is a structural diagram showing the fuel supply device 10.

[0045] 4, in place of the check valve 60 (see FIG. 1) of the first embodiment, a solenoid valve 70 that opens and closes the upstream bypass line 50 is provided midway along the upstream bypass line 50. Also, a pressure sensor 72 that detects the fuel pressure in the downstream supply line 30 is provided in the downstream supply line 30. The detection result of the pressure sensor 72 is input to a solenoid valve control unit 40a of the ECU 40. The solenoid valve control unit 40a is included in the ECU 40.

[0046] The solenoid valve control unit 40a opens the solenoid valve 70 during initial fuel filling. The solenoid valve control unit 40a also closes the solenoid valve 70 while the fuel pump 20 is operating. The solenoid valve control unit 40a also opens and closes the solenoid valve 70 based on the detection result from the pressure sensor 72 while the fuel pump 20 is operating. That is, when the fuel pressure in the downstream supply line 30 becomes higher than a normal value, the solenoid valve control unit 40a closes the solenoid valve 70 to prevent backflow in the upstream bypass line 50. The solenoid valve control unit 40a also opens the solenoid valve 70 when the fuel pressure in the downstream supply line 30 is lower than a normal value, i.e., when the pressure sensor 72 detects a drop in fuel pressure due to a pressure abnormality caused by air entrapment due to cavitation or the like (for example, an abnormality in which the fuel pressure does not increase no matter how much the fuel pump 20 is rotated).

[0047] (Advantages of embodiment 2) According to this embodiment, the solenoid valve 70 closes based on the detection result of the pressure sensor 72, thereby preventing backflow in the upstream bypass line 50. This makes it possible to suppress a decrease in the output of the fuel pump 20. Furthermore, when the pump output of the fuel pump 20 decreases due to cavitation, the solenoid valve 70 opens to discharge vapor from the pump chamber 23.

[0048] [Embodiment 3] This embodiment is a modification of the first embodiment (see FIG. 1), so the modified parts will be described, and the same parts as those in the first embodiment will be assigned the same reference numerals and redundant description will be omitted. FIG. 5 is a configuration diagram showing a fuel supply device 110. Parts modified in this embodiment will be assigned reference numerals in the 100s.

[0049] As shown in Fig. 5, a junction 130a is provided midway along the downstream supply line 130. The fuel pump 20 (more specifically, the communication port 22c (see Fig. 2)) and the junction 130a of the downstream supply line 130 are connected via a downstream bypass line 150. In this embodiment, the upstream supply line 14 (see Fig. 1) of the first embodiment is modified to an upstream supply line 114 that omits the upstream bypass line 50 including the branching portion 14a.

[0050] A check valve 160 that prevents backflow is provided in the downstream bypass line 150. The check valve 160 allows fuel to flow (forward flow) from the fuel pump 20 to the downstream supply line 130, and blocks (prevents) fuel from flowing in the opposite direction (backflow). In the downstream bypass line 150, the part upstream of the check valve 160 is referred to as an upstream line section 150a, and the part downstream of the check valve 160 is referred to as a downstream line section 150b. FIG. 6 is a cross-sectional view showing the check valve 160.

[0051] The check valve 160 has the same basic configuration as the check valve 60 of the first embodiment (see FIG. 3), and therefore the same components are denoted by the same reference numerals and their description will be omitted. The check valve 160 in FIG. 6 is arranged upside down compared to the check valve 60 in FIG. 3. The downstream end of the upstream line section 150a is connected to the inlet 61a. The upstream end of the downstream line section 150b is connected to the outlet 61b.

[0052] The check valve 160 allows forward flow in the downstream bypass line 150 when it is open (see solid line 62 in Figure 6), and prevents reverse flow in the downstream bypass line 150 when it is closed (see dashed line 62 in Figure 6).

[0053] (Function of the fuel supply device 110) Assume now that the fuel supply flow path from the fuel tank 12 to the engine 32 is empty. This fuel supply flow path includes the upstream supply line 14, the downstream supply line 30, the flow path of the pump section 21 of the fuel pump 20, and the downstream bypass line 150. In this state, when the ignition switch of the engine 32 is turned on, the shutoff valve 15 opens. Then, compressed fuel in the fuel tank 12 is supplied to the combustion chamber 33 of the engine 32 via the upstream supply line 114, the fuel pump 20, and the downstream supply line 130 due to the ejection pressure from the fuel tank 12. This fuel flow discharges vapor (air) in the upstream supply line 114, the fuel pump 20, and the downstream supply line 130 into the combustion chamber 33 of the engine 32.

[0054] At this time, a portion of the vapor (air) in the pump chamber 23 is discharged to the downstream supply line 130 via the downstream bypass line 150. That is, the vapor in the pump chamber 23 is discharged from both the downstream supply line 130 and the downstream bypass line 150. This improves the vapor discharge performance from the pump chamber 23, allowing the pump chamber 23 to be filled with fuel quickly. At this time, the check valve 160 is in an open state (see solid line 62 in FIG. 6).

[0055] Furthermore, the fuel pump 20 is driven after a predetermined time has elapsed since the ignition switch was turned on. When the fuel pressure in the downstream line section 150b becomes higher than the fuel pressure in the upstream line section 150a, the valve element 62 closes (see the two-dot chain line 62 in FIG. 6). This prevents backflow in the downstream bypass line 150.

[0056] (Advantages of embodiment 3) According to the third embodiment, when the pump chamber 23 of the fuel pump 20 is initially filled with fuel while the fuel pump 20 is empty, the vapor in the pump chamber 23 is discharged from both the downstream supply line 130 and the downstream bypass line 150 due to the flow of compressed fuel into the pump chamber 23. This improves the vapor discharge performance from the pump chamber 23. Therefore, it is possible to improve the efficiency of filling the pump chamber 23 with fuel when the pump chamber 23 is initially filled with fuel. In other words, it is possible to shorten the time required to fill the pump chamber 23 with fuel.

[0057] Furthermore, the check valve 160 can prevent backflow in the downstream bypass line 150. This can suppress a decrease in the output of the fuel pump 20.

[0058] [Embodiment 4] This embodiment is a modification of the third embodiment (see FIG. 5), so the modifications will be described, and the same parts as those in the third embodiment will be assigned the same reference numerals and will not be described again. FIG. 7 is a structural diagram showing a fuel supply device 110.

[0059] 7, in this embodiment, similar to the second embodiment (see FIG. 4), the check valve 160 in the downstream bypass line 150 of the third embodiment (see FIG. 5) is replaced with a solenoid valve 170, and a pressure sensor 172 is provided in the downstream supply line 130. The detection result of the pressure sensor 172 is input to the solenoid valve control unit 40a of the ECU 40, as in the second embodiment (see FIG. 4).

[0060] The solenoid valve control unit 40a opens the solenoid valve 170 during initial fuel filling. The solenoid valve control unit 40a also closes the solenoid valve 170 while the fuel pump 20 is operating. The solenoid valve control unit 40a also opens and closes the solenoid valve 170 based on the detection result of the pressure sensor 172 while the fuel pump 20 is operating. That is, when the fuel pressure in the downstream supply line 130 becomes higher than a normal value, the solenoid valve control unit 40a closes the solenoid valve 170 to prevent backflow in the downstream bypass line 150. The solenoid valve control unit 40a also opens the solenoid valve 170 when the fuel pressure in the downstream supply line 130 is lower than a normal value, i.e., when the pressure sensor 172 detects a drop in fuel pressure due to a pressure abnormality caused by air entrapment due to cavitation or the like (for example, an abnormality such that the fuel pressure does not increase no matter how much the fuel pump 20 is rotated).

[0061] (Advantages of embodiment 4) According to this embodiment, the solenoid valve 170 closes based on the detection result of the pressure sensor 172, thereby preventing backflow in the downstream bypass line 150. This makes it possible to suppress a decrease in the output of the fuel pump 20. Furthermore, when the pump output of the fuel pump 20 decreases due to cavitation, the solenoid valve 170 opens to discharge vapor from the pump chamber 23.

[0062] [Other embodiments] The technology disclosed in this specification is not limited to the above-described embodiment and can be implemented in various other forms. For example, the technology disclosed in this specification can be applied to liquid fuels other than compressed fuel. The fuel pump 20 may be driven simultaneously with the start of the engine 32. The fuel tank 12 may be a fuel container such as a cylinder. The fuel pump 20 may be a non-positive displacement pump other than a Westco pump. The fuel pump 20 may be configured to discharge fuel from the pump section 21 to the outside via the inside of the motor section 26. The check valves 60 and 160 may be omitted. [Explanation of symbols]

[0063] 10 Fuel supply device 12 Fuel tank 14 Upstream supply line 20 Fuel pump 30 Downstream Supply Line 32 Engine (fuel demand equipment) 40 ECU (control means) 50 Upstream bypass line 60 Check valve 70 Solenoid valve 72 Pressure Sensor 110 Fuel supply system 114 Upstream supply line 130 Downstream Supply Line 150 Downstream Bypass Line 160 Check valve 170 Solenoid valve 172 Pressure Sensor

Claims

1. A fuel supply device including an upstream supply line connecting a fuel tank that stores fuel and a fuel pump, and a downstream supply line connecting the fuel pump and a fuel demand device, a fuel supply system including an upstream bypass line branching off from the upstream supply line and joining the pump chamber of the fuel pump;

2. 2. The fuel supply system according to claim 1, The fuel supply device, wherein the upstream bypass line is provided with a check valve for preventing backflow.

3. 2. The fuel supply system according to claim 1, a pressure sensor for detecting the fuel pressure in the downstream supply line; a solenoid valve that closes based on the detection result of the pressure sensor to prevent backflow in the upstream bypass line; A fuel supply device is provided.

4. A fuel supply device including an upstream supply line connecting a fuel tank that stores fuel and a fuel pump, and a downstream supply line connecting the fuel pump and a fuel demand device, a downstream bypass line branching off from a pump chamber of the fuel pump and joining the downstream supply line;

5. 5. The fuel supply system according to claim 4, The fuel supply device further comprises a check valve provided in the downstream bypass line to prevent backflow.

6. 5. The fuel supply system according to claim 4, a pressure sensor for detecting the fuel pressure in the downstream supply line; a solenoid valve that closes based on the detection result of the pressure sensor to prevent backflow in the downstream bypass line; A fuel supply device is provided.

7. 5. The fuel supply device according to claim 1 or 4, The fuel is a compressed fuel such as liquefied ammonia fuel, and is supplied to the pump chamber by the ejection pressure from the fuel tank.

Images