High-speed engine fuel oil pipeline system and exhaust, pressure building and pressure stabilizing method thereof

Abstract

The invention discloses a high-speed engine fuel oil pipeline system and an exhaust, pressure building and pressure stabilizing method thereof. The high-speed engine fuel oil pipeline system comprises a front low-pressure fuel oil pipeline and a rear fuel oil pipeline. The front low-pressure fuel oil pipeline comprises a daily oil tank, a three-way electronic valve, a DC 24V electric fuel oil pre-supply pump, a fuel oil coarse filter, a low-pressure fuel oil delivery pump, a manual fuel oil pre-supply pump and a duplex fuel oil filter; the rear fuel oil pipeline comprises a high-pressure oil pump, an oil sprayer, an engine cylinder cover, an oil-gas separator, a flow meter and a fuel oil cooler. According to the high-speed engine fuel oil pipeline system and the exhausting, pressure building and pressure stabilizing method thereof, rapid starting and rapid air leakage elimination of a high-speed engine are achieved, the sealing performance of the high-speed engine fuel oil system is checked, the pressure is prevented from being too high in the pre-supply pump exhausting operation process, and therefore smooth starting and initial stable operation of the high-speed engine are guaranteed. And the reliable operation of the high-speed engine is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a fuel pipeline system for a high-speed engine and its methods for exhaust, pressure building, and pressure stabilization. Background Art

[0002] At present, the engine-driven fuel transfer pumps for high-speed engines are mostly gear pumps. Due to the working characteristics of gear pumps, when the fuel tank is lower than the inlet of the fuel transfer pump of the high-speed engine, or after the fuel filter, high-pressure oil pump, or fuel pipe is maintained and replaced in the fuel system, there is air in the fuel pipeline before the high-speed engine runs, resulting in difficult engine starting or unstable operation. It may even cause "cavitation" of the high-pressure oil pump and injector, accelerating wear, and even posing a fire risk. Moreover, if the high-speed engine is shut down for a long time, the fuel in the fuel pipeline will return, and there will be a problem of re-establishing the oil pressure. When there is a leakage fault in the low-pressure pipeline, it is not easy to locate the leakage point because the fuel pipeline in front of the fuel transfer pump is in a negative pressure state. Therefore, ensuring the smooth start and initial stable operation of the high-speed engine is an urgent problem to be solved at present. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects, and provide a fuel pipeline system for a high-speed engine and its methods for exhaust, pressure building, and pressure stabilization, which can ensure the smooth start and initial stable operation of the high-speed engine, avoid incomplete air discharge from the fuel system before the high-speed engine runs, and effectively solve the problems in the background art.

[0004] To achieve the above object, the present invention provides the following technical solution: A fuel pipeline system for a high-speed engine, comprising a front low-pressure fuel pipeline and a rear fuel pipeline;

[0005] The front low-pressure fuel pipeline includes a daily fuel tank, a three-way solenoid valve, a DC24V electric fuel pre-feed pump, a fuel coarse filter, a low-pressure fuel transfer pump, a manual fuel pre-feed pump, and a duplex fuel filter;

[0006] The rear fuel pipeline includes a high-pressure oil pump, an injector, an engine cylinder head, an oil-gas separator, a flow meter, and a fuel cooler.

[0007] As a preferred technical solution of the present invention, the daily-use fuel tank is connected in series in the fuel pipeline through the fuel inlet pipe LY1 and the quick-closing valve. The quick-closing valve is connected to the first check valve through the fuel inlet pipe LY2. The first check valve is connected to the three-way solenoid valve through the fuel inlet pipe LY3. One end of the three-way solenoid valve is connected to the fuel coarse filter through the fuel inlet pipe LY4. The other end of the three-way solenoid valve is connected to the DC24V electric fuel pre-feed pump through the fuel inlet pipe LY7. The DC24V electric fuel pre-feed pump is connected to the daily-use fuel tank through the fuel inlet pipe LY8. The fuel coarse filter is connected to the second check valve through the fuel inlet pipe LY5. The second check valve is connected to the low-pressure fuel delivery pump and the manual fuel pre-feed pump respectively through the fuel inlet pipe LY6. The low-pressure fuel delivery pump is connected to the third check valve through the fuel inlet pipe LY9. The manual fuel pre-feed pump is equipped with pipe connection bolts for automatic or manual air bleeding and oil draining. One ends of the third check valve and the manual fuel pre-feed pump are connected to the double fuel filter through the fuel inlet pipe LY10. The double fuel filter is equipped with a bleed plug I and a bleed plug II for automatic or manual air bleeding and oil draining. The double fuel filter is connected to the pressure gauge through the fuel inlet pipe LY12. The pressure gauge is connected to the over-guarantee solenoid valve through a pipeline;

[0008] The high-pressure oil pump includes an oil inlet, a relief valve and an oil outlet. The oil inlet is connected to the over-guarantee solenoid valve through the fuel inlet pipe LY13. The relief valve is connected to the fourth check valve through a fuel pipeline. The fourth check valve is connected to the daily-use fuel tank through the fuel return pipe HY5. The oil outlet of the high-pressure oil pump is connected to the fuel injector through the high-pressure oil pipe HY1. One end of the fuel injector is connected to the engine cylinder head. The injector return port in the fuel injector is connected to the fifth check valve through the fuel return pipe HY6. The fifth check valve is connected to the oil-gas separator inlet in the oil-gas separator through the fuel return pipe HY4. The fuel return pipe HY4 is connected to the over-guarantee solenoid valve through the fuel inlet pipe LY11. A sixth check valve is arranged on the fuel inlet pipe LY11. The oil-gas separator pressure-stabilized oil outlet in the oil-gas separator is connected to the flow meter through the fuel return pipe ZQ2. The flow meter is connected to the fuel inlet pipe LY1 through a pipeline. The oil-gas separator return port in the oil-gas separator is connected to the stop valve I through the fuel return pipe ZQ1. The stop valve I is connected to the fuel cooler through the fuel return pipe ZQ3. The fuel cooler is connected to the daily-use fuel tank through the fuel return pipe ZQ4.

[0009] As a preferred technical solution of the present invention, the daily-use fuel tank includes a PLC control system, a pressure sensor and a gas release device. When the pressure sensor signals that the air pressure in the fuel system of the daily-use fuel tank exceeds the limit, the gas release device of the daily-use fuel tank is automatically opened through the logical judgment of the PLC control system and automatically closed when a certain pressure is reached.

[0010] As a preferred technical solution of the present invention, the rear fuel pipeline further includes a fuel leakage alarm system, which includes a fuel leakage sensor, a leakage overflow pipe HY3, and a leakage fuel tank. The fuel leakage sensor is arranged in the connecting oil pipe HY2, the connecting oil pipe HY2 is connected to the high-pressure oil pipe HY1, and the other end of the connecting oil pipe HY2 is connected to the leakage fuel tank through the leakage overflow pipe HY3.

[0011] An exhaust and pressure building method for a fuel pipeline system of a high-speed engine includes an exhaust and pressure building method realized by a DC24V electric fuel pre-supply pump and an exhaust and pressure building method realized by a manual fuel pre-supply pump.

[0012] As a preferred technical solution of the present invention, the exhaust and pressure building method of the DC24V electric fuel pre-supply pump is as follows: in the state of short-time shutdown of the high-speed engine, the PLC control system controls the DC24V electric fuel pre-supply pump to act, and at the same time, the PLC control system controls the three-way solenoid valve to switch to connect the fuel inlet pipe LY4 and the fuel inlet pipe LY7. When it is ensured that the low-pressure fuel delivery pump is not stuck, keep the DC24V electric fuel pre-supply pump continuing to pump oil. Manually and slowly loosen the bleed plug of the DC24V electric fuel pre-supply pump until the fuel flowing out has no bubbles, then manually tighten the bleed plug of the DC24V electric fuel pre-supply pump, keep the DC24V electric fuel pre-supply pump continuing to pump oil, manually and slowly loosen the bleed plugs I and II of the double fuel filter until the fuel flowing out has no bubbles, then manually tighten the bleed plugs I and II of the double fuel filter, keep the DC24V electric fuel pre-supply pump continuing to pump oil, manually and slowly loosen the overflow valve of the high-pressure oil pump until the fuel flowing out has no bubbles, manually and slowly tighten the overflow valve. After operating the bleed of the DC24V electric fuel pre-supply pump, the double fuel filter and the high-pressure oil pump, observe that the reading value on the pressure gauge display panel does not jump, indicating that the exhaust of the fuel system is successful, and the reading value of the pressure gauge being 0.3 MPa indicates that the pressure building is successful.

[0013] As a preferred technical solution of the present invention, the method for exhausting air and building pressure of the manual fuel pre-supply pump is as follows: when the high-speed engine is in a shutdown state, the PLC control system controls the three-way solenoid valve to switch to connect the fuel inlet pipe LY3 and the fuel inlet pipe LY4. First, slowly loosen the pipe connection bolt of the manual fuel pre-supply pump, and manually operate the manual fuel pre-supply pump to pump fuel until the fuel flowing out has no bubbles. Then, manually tighten the pipe connection bolt. Manually and slowly loosen the air release plugs I and II of the double fuel filter, and manually operate the manual fuel pre-supply pump to pump fuel until the fuel flowing out has no bubbles. While continuing to manually operate the manual fuel pre-supply pump to pump fuel, manually tighten the air release plugs I and II of the double fuel filter. Manually and slowly loosen the overflow valve of the high-pressure oil pump, and manually operate the manual fuel pre-supply pump to pump fuel until the fuel flowing out has no bubbles. Manually and slowly loosen the overflow valve. After exhausting air from the manual fuel pre-supply pump, the double fuel filter and the high-pressure oil pump, observe that the value on the pressure gauge display panel does not jump, indicating that the fuel system has successfully exhausted air. When the value displayed on the pressure gauge is 0.3 MPa, it indicates that the pressure has been successfully built up.

[0014] A method for stabilizing the pressure of the fuel pipeline system of a high-speed engine. When the high-speed engine successfully shuts down, the fuel is still in a state where the fuel pipeline is full of fuel. The fuel is collected from the fuel return pipe HY5 and the fuel return pipe HY6 of the fuel injector to the fuel return pipe HY4. The fuel in the fuel return pipe HY4 flows to the oil-gas separator's oil inlet. According to the PLC control logic of the flow meter, the oil-gas separator distributes the fuel flow and connects part of the fuel to the high-pressure oil pipe HY1 through the pressure-stabilizing oil outlet and returns it to the daily-use fuel tank.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The fuel pipeline system of the high-speed engine and its methods for exhausting air, building pressure and stabilizing pressure solve the problems that when the fuel tank is lower than the inlet of the high-speed engine fuel delivery pump or after the fuel filter, high-pressure oil pump or fuel pipe in the fuel system is maintained or replaced, it is difficult for the high-speed engine to start or the operation is unstable due to the presence of air in the fuel pipeline before the engine runs; (2) It solves the problem that when the high-speed engine shuts down for a long time, the fuel in the fuel pipeline will return, resulting in the high-pressure oil pump re-establishing the oil pressure and making it impossible for the high-speed engine to start quickly; (3) It solves the problem that it is not easy to detect the air leakage point because the fuel pipeline in front of the fuel delivery pump is in a negative pressure state; (4) It proposes a method for exhausting air and building pressure of the pre-supply pump and measures to avoid fuel leakage and excessive pressure, thereby realizing the problems of quick start of the high-speed engine, quick exhausting of air leakage, checking the tightness of the high-speed engine fuel system, avoiding excessive pressure during the process of operating the pre-supply pump to exhaust air, etc., so as to ensure the smooth start and initial stable operation of the high-speed engine, enabling the operator to understand potential risks in advance for timely handling and avoiding the occurrence of equipment damage or safety accidents. Description of the Drawings

[0016] Figure 1 Schematic diagram of the fuel pipeline system of the present invention;

[0017] Figure 2 Flow chart of the fuel pressure stabilization method after the high-speed engine of the present invention shuts down;

[0018] Figure 3 Flow chart of avoiding excessive pressure during the use of the manual fuel pre-feed pump in the present invention;

[0019] Figure 4 Flow chart of avoiding excessive pressure during the use of the DC24V electric fuel pre-feed pump in the present invention;

[0020] Figure 5 Flow chart of the redundant design of the fuel pre-feed system of the present invention;

[0021] Figure 6 Flow chart of the redundant design of the exhaust of the fuel system of the present invention.

[0022] In the figure: 1 daily-use fuel tank, 2 quick shut-off valve, 3 first one-way valve, 4 three-way solenoid valve, 5 second one-way valve, 6 DC24V electric fuel pre-feed pump, 6-1 bleed bolt, 7 low-pressure fuel transfer pump, 8 manual fuel pre-feed pump, 8-1 pipe connection bolt, 9 third one-way valve, 10 double fuel filter, 11 high-pressure oil pump, 12 fourth one-way valve, 13 injector, 14 fifth one-way valve, 15 oil-gas separator, 15-1 oil-gas separator inlet, 15-2 oil-gas separator stabilized oil outlet, 15-3 oil-gas separator return port, 16 stop valve I, 17 pressure sensor, 18 bleeding device, 19 inlet port, 20 overflow valve, 21 bleed plug I, 22 bleed plug II, 23 injector return port, 24 engine cylinder head, 25 observation window, 26 stop valve II, 27 sixth one-way valve, 28 outlet port, K1 fuel cooler, K2 fuel coarse filter, K3 over-guarantee solenoid valve, K4 leakage fuel tank, K5 fuel leakage sensor, K6 pressure gauge, K7 flow meter. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] As Figure 1 , the present invention provides a technical solution: a fuel pipeline system for a high-speed engine, including a front low-pressure fuel pipeline and a rear fuel pipeline;

[0025] The front low-pressure fuel pipeline includes a daily-use fuel tank 1, a three-way solenoid valve 4, a DC24V electric fuel pre-feed pump 6, a fuel coarse filter K2, a low-pressure fuel transfer pump 7, a manual fuel pre-feed pump 8, and a duplex fuel filter 10;

[0026] The daily-use fuel tank 1 is equipped with a liquid level sensor, a low liquid level alarm switch, a high liquid level alarm switch, and a visual liquid level gauge, and is provided with a make-up oil inlet, a fuel outlet, a fuel return inlet, an exhaust port, an overflow port, and a drain port. The liquid level sensor, the low liquid level alarm switch, and the high liquid level alarm switch are respectively connected to the control module by signals. The daily-use fuel tank 1 itself has a stop valve II26, which is well-known technology and will not be elaborated here;

[0027] The daily-use fuel tank 1 and a quick shut-off valve 2 are connected in series in the fuel pipeline through a fuel inlet pipe LY1. The quick shut-off valve 2 is connected to a first check valve 3 through a fuel inlet pipe LY2. The first check valve 3 is connected to the three-way solenoid valve 4 through a fuel inlet pipe LY3. One end of the three-way solenoid valve 4 is connected to the fuel coarse filter K2 through a fuel inlet pipe LY4. The other end of the three-way solenoid valve 4 is connected to the DC24V electric fuel pre-feed pump 6 through a fuel inlet pipe LY7. The DC24V electric fuel pre-feed pump 6 is connected to the daily-use fuel tank 1 through a fuel inlet pipe LY8 and is connected in parallel with the fuel inlet pipe LY1, the quick shut-off valve 2, and the first check valve 3 in the fuel pipeline. The DC24V electric fuel pre-feed pump 6 itself has the function of a stop valve. The fuel coarse filter K2 is connected to a second check valve 5 through a fuel inlet pipe LY5. The second check valve 5 is connected to the low-pressure fuel transfer pump 7 and the manual fuel pre-feed pump 8 respectively through a fuel inlet pipe LY6. The low-pressure fuel transfer pump 7 is connected to a third check valve 9 through a fuel inlet pipe LY9. The manual fuel pre-feed pump 8 is equipped with a pipe connection bolt 8-1 for automatic or manual air bleeding and oil draining. The manual fuel pre-feed pump 8 is connected in parallel with the low-pressure fuel transfer pump 7, the fuel inlet pipe LY9, and the third check valve 9 in the fuel pipeline and is connected to the duplex fuel filter 10 through a fuel inlet pipe LY10. The duplex fuel filter 10 is equipped with a bleed plug I21 and a bleed plug II22 for automatic or manual air bleeding and oil draining. The duplex fuel filter 10 is connected to a pressure gauge K6 through a fuel inlet pipe LY12. The pressure gauge K6 is connected to an over-guarantee solenoid valve K3 through a pipeline;

[0028] The post-fuel pipeline includes a high-pressure oil pump 11, an injector 13, an engine cylinder head 24, an oil-gas separator 15, a flowmeter K7, and a fuel cooler K1. The high-pressure oil pump 11 includes an oil inlet 19, a relief valve 20, and an oil outlet 28. The oil inlet 19 is connected to an over-guarantee solenoid valve K3 through a fuel inlet pipe LY13. The relief valve 20 is connected to a fourth check valve 12 through a fuel pipeline. The fourth check valve 12 is connected to a daily-use fuel tank 1 through a fuel return pipe HY5. The oil outlet of the high-pressure oil pump 11 is connected to the injector 13 through a high-pressure oil pipe HY1. The injector 13 atomizes the fuel provided by the high-pressure oil pump 11 and sprays it into the diesel engine cylinder head 24. The injector return oil port 23 in the injector 13 is connected to a fifth check valve 14 through a fuel return pipe HY6. The fifth check valve 14 is connected to an oil-gas separator inlet 15-1 in the oil-gas separator 15 through a fuel return pipe HY4. An observation window 25 is arranged outside the oil-gas separator 15 for workers to observe conveniently. The fuel filling the oil-gas separator 15 flows out through an oil-gas separator pressure-stabilizing oil outlet 15-2 and an oil-gas separator return oil port 15-3 respectively. The fuel return pipe HY4 is connected to the over-guarantee solenoid valve K3 through a fuel inlet pipe LY11. A sixth check valve 27 is arranged on the fuel inlet pipe LY11. The oil-gas separator pressure-stabilizing oil outlet 15-2 in the oil-gas separator 15 is connected to the flowmeter K7 through a fuel return pipe ZQ2. The flowmeter K7 is connected to the fuel inlet pipe LY1 through a pipeline. The oil-gas separator return oil port 15-3 in the oil-gas separator 15 is connected to a stop valve I16 through a fuel return pipe ZQ1. The stop valve I16 is connected to the fuel cooler K1 through a fuel return pipe ZQ3. The fuel cooler K1 is connected to the daily-use fuel tank 1 through a fuel return pipe ZQ4.

[0029] Further, for the convenience of exhaust, the daily-use fuel tank 1 includes a PLC control system, a pressure sensor 17, and a gas release device 18. When the pressure sensor 17 collects signals and the air pressure in the fuel system of the daily-use fuel tank 1 exceeds the limit, the gas release device 18 of the daily-use fuel tank 1 is automatically opened through the logical judgment of the PLC control system and automatically closed after reaching a certain pressure.

[0030] Further, the post-fuel pipeline also includes a fuel leakage alarm system. The fuel leakage alarm system includes a fuel leakage sensor K5, a leakage overflow pipe HY3, and a leakage fuel tank K4. The fuel leakage sensor K5 is arranged in a connecting oil pipe HY2. The connecting oil pipe HY2 is connected to the high-pressure oil pipe HY1. The other end of the connecting oil pipe HY2 is connected to the leakage fuel tank K4 through the leakage overflow pipe HY3. The fuel leakage sensor K5 detects and alarms the bursting and oil leakage of the high-pressure oil pipe 11, reducing the fuel leakage points during use and lowering the cost. The low-pressure fuel delivery pump 7 can accelerate the flow of fuel, thereby meeting the starting and pressure-building requirements for entering the high-pressure oil pump.

[0031] The present invention provides a method for exhausting air and building pressure for a DC24V electric fuel pre-feed pump 6, which can be described as follows: when the high-speed engine is in a short-term shutdown state, the PLC control system controls the operation of the DC24V electric fuel pre-feed pump 6. At the same time, the PLC control system controls the three-way solenoid valve 4 to switch to connect the fuel inlet pipe LY4 and the fuel inlet pipe LY7. When it is ensured that the low-pressure fuel delivery pump 7 is not stuck, the DC24V electric fuel pre-feed pump 6 continues to pump fuel. Manually and slowly loosen the air release plug 6-1 of the DC24V electric fuel pre-feed pump 6 until the fuel flowing out has no bubbles, and then manually tighten the air release plug 6-1 of the DC24V electric fuel pre-feed pump 6. Keep the DC24V electric fuel pre-feed pump 6 continuing to pump fuel. Manually and slowly loosen the air release plug I21 and the air release plug II22 of the double fuel filter 10 until the fuel flowing out has no bubbles, and then manually tighten the air release plug I21 and the air release plug II22 of the double fuel filter 10. Keep the DC24V electric fuel pre-feed pump 6 continuing to pump fuel. Manually and slowly loosen the overflow valve 20 of the high-pressure oil pump 11 until the fuel flowing out has no bubbles, and then manually and slowly tighten the overflow valve 20. After exhausting air from the DC24V electric fuel pre-feed pump 6, the double fuel filter 10 and the high-pressure oil pump 11, observe that the reading on the pressure gauge display panel does not jump, indicating that the fuel system has successfully exhausted air. When the reading on the pressure gauge is 0.3 MPa, it indicates that the pressure has been successfully built up.

[0032] Preferably, if there is no fuel flowing out during the process of exhausting air from the DC24V electric fuel pre-feed pump 6, the double fuel filter 10 and the high-pressure oil pump 11, it is necessary to confirm whether the DC24V electric fuel pre-feed pump 6 is operating normally and check whether the fuel inlet pipe LY8 from the daily fuel tank 1 to the DC24V electric fuel pre-feed pump 6 is blocked or leaking.

[0033] Preferably, if there are still bubbles after repeatedly exhausting air during the operation of the DC24V electric fuel pre-feed pump 6, the double fuel filter 10 and the high-pressure oil pump 11, the first step is to check whether the fuel pipeline is damaged or the connection joints are loose; the second step is to confirm whether the fuel coarse filter K2 and the double fuel filter 10 are blocked; the third step is to confirm whether the oil level in the daily fuel tank 1 is too low to avoid the suction pipe being exposed outside the liquid level.

[0034] The present invention provides a method for exhausting air and building pressure of the manual fuel pre - supply pump 8, which can be described as follows: when the high - speed engine is in a shutdown state, the PLC control system controls the three - way solenoid valve 4 to switch to connect the fuel inlet pipe LY3 and the fuel inlet pipe LY4. First, slowly loosen the pipe - connecting bolt 8 - 1 of the manual fuel pre - supply pump 8, and operate the manual fuel pre - supply pump 8 by hand to pump fuel until the fuel flowing out has no bubbles. Then, manually tighten the pipe - connecting bolt 8 - 1. Manually and slowly loosen the air - bleeding plug I 21 and the air - bleeding plug II 22 of the double - fuel filter 10, and operate the manual fuel pre - supply pump 8 by hand to pump fuel until the fuel flowing out has no bubbles. While continuing to operate the manual fuel pre - supply pump 8 by hand to pump fuel, manually tighten the air - bleeding plug I 21 and the air - bleeding plug II 22 of the double - fuel filter 10. Manually and slowly loosen the overflow valve 20 of the high - pressure oil pump 11, and operate the manual fuel pre - supply pump 8 by hand to pump fuel until the fuel flowing out has no bubbles. Manually and slowly turn the overflow valve 20. After exhausting air from the manual fuel pre - supply pump 8, the double - fuel filter 10, and the high - pressure oil pump 11, observe that the value on the pressure gauge display panel does not jump, indicating that the fuel system has successfully exhausted air. When the value shown on the pressure gauge is 0.3 MPa, it indicates that the pressure has been successfully built up.

[0035] Preferably, during the process of exhausting air from the manual fuel pre - supply pump 8, the double - fuel filter 10, and the high - pressure oil pump 11, if no fuel flows out, it is necessary to confirm whether the manual fuel pre - supply pump 8 operates normally and check whether the fuel pipeline from the daily - use fuel tank 1 to the manual fuel pre - supply pump 8 is blocked or leaking.

[0036] Preferably, when repeatedly exhausting air during the operation of the manual fuel pre - supply pump 8, the double - fuel filter 10, and the high - pressure oil pump 11 and there are still bubbles, it is necessary to: first, check whether the fuel pipeline is damaged or the connection joints are loose; second, confirm whether the fuel coarse filter K2 and the double - fuel filter 10 are blocked; third, confirm whether the oil level in the daily - use fuel tank 1 of the fuel is too low to avoid the suction pipe being exposed outside the liquid level.

[0037] As Figure 2 The present invention provides a method for stabilizing the pressure of the fuel pipeline system of a high - speed engine after the high - speed engine has successfully run and shut down, which can be described as follows: at the moment when the high - speed engine successfully runs and shuts down, the fuel is still in a state where the fuel pipeline is full of fuel. The fuel is collected through the fuel return pipe HY5 and the fuel return pipe HY6 of the fuel injector 13 into the fuel return pipe HY4. The fuel in the fuel return pipe HY4 flows to the oil - gas separator 15 at the oil inlet 15 - 1. According to the PLC control logic of the flowmeter K7, the oil - gas separator 15 distributes the fuel flow and part of the fuel is connected to the high - pressure pipe HY1 through the pressure - stabilizing oil outlet 15 - 2 and returns to the daily - use fuel tank 1.

[0038] After the engine stops, the pressure stabilization system forms a closed-loop circuit for the entire fuel system through the quick-closing valve 2, the first one-way valve 3, the three-way solenoid valve 4, the fuel coarse filter K2, the second one-way valve 5, the low-pressure fuel transfer pump 7, the double fuel filter 10, the over-guarantee solenoid valve K3, the pressure gauge K6, the fuel return pipes LY1 to LY13, the high-pressure oil pump 11, the injector 13, the injector return port 23 pipeline, the fifth one-way valve 14, the oil-gas separator inlet 15-1, the oil-gas separator pressure-stabilized outlet 15-2, and the flowmeter K7, maintaining the pressure in the fuel pipeline. It can also be described as that the return oil volume of the high-pressure oil pump 11 is large and the oil temperature is high. If it returns to the inlet pipe, it will affect the cooling of the fuel injection pump, causing the plunger pair to get stuck. At the same time, due to the high oil temperature, it will affect the fuel volume entering the cylinder, resulting in a decrease in the power of the high-speed engine. Therefore, through the internal design of the oil-gas separator 15, a large part of the return oil of the high-pressure oil pump 11 is returned to the daily-use fuel tank 1, leaving a small part to maintain the pressure of the oil-gas separator 15; also considering that the return oil volume of the injector 13 is small, in order to solve the problem of poor return oil of the injector 13 due to the certain pressure of the fuel in the inlet pipe, a fifth one-way valve 14 is designed in the injector return pipeline. The fifth one-way valve 14 can only flow in one direction and cannot flow in the reverse direction, finally realizing the fuel pressure stabilization system after the high-speed engine successfully runs and stops.

[0039] The present invention provides measures to avoid fuel leakage before the pre-feed pump pumps oil. It can be described as follows: Before the pre-feed pump pumps oil, first check whether there are looseness, cracks in the bodies and connections of each fuel pipeline, the double fuel filter 10, the DC24V electric fuel pre-feed pump 6, and the manual fuel pre-feed pump 8, and whether the filter element of the double fuel filter 10 is tightly installed and leaking oil. Secondly, check whether the sealing rings of the DC24V electric fuel pre-feed pump 6 and the manual fuel pre-feed pump 8 are aged or damaged. Thirdly, check whether the tightness of the daily-use fuel tank 1 is good; the fuel pre-feed operation control should be standardized. It can be described as that the manual fuel pre-feed pump 8 should be slowly operated to pump oil and pressurize, and at the same time observe whether there is oil leakage or dripping in the fuel pipeline and the body of the fuel filter 10; it can also be described as observing whether there is oil leakage or dripping in the fuel pipeline, the fuel filter 10, and the body of the DC24V electric fuel pre-feed pump 6 during the 15-minute process of the PLC control system controlling the DC24V electric fuel pre-feed pump 6 to pump oil; after the pre-feed pump finishes pumping oil, stand still for 10 minutes. After pressurization, wait for ten minutes and then watch whether the pressure gauge K6 jumps and whether there is slow leakage due to poor pressure maintenance. Finally, complete cleaning the oil stains on the surface of the fuel pipeline and pay attention to whether there are new leakage points.

[0040] Such as Figure 3, the present invention provides measures to avoid excessive pressure during the fuel pumping process of the manual fuel pre-feed pump 8, which can be described as follows: The manual fuel pre-feed pump 8 is generally a plunger type or a diaphragm type. When operating the manual fuel pre-feed pump 8, whether the resistance increases significantly or whether the pump rod of the manual fuel pre-feed pump 8 is difficult to press down. Moreover, whether the value displayed by the pressure gauge K6 is ≥ 0.3 MPa. If the resistance increases when operating the manual fuel pre-feed pump 8, or the pump rod of the manual fuel pre-feed pump 8 is difficult to press down, or the value is ≥ 0.3 MPa, it indicates that the pressure in the fuel system pipeline is close to the limit value, and the pressurization should be stopped.

[0041] Preferably, the measures to avoid excessive pressure during the fuel pumping process of the manual fuel pre-feed pump 8 can be described as follows: After the pressure has exceeded the limit value of 0.3 MPa, pressure relief is completed through manual or automatic design to ensure the safety of the fuel pipeline; Manual pressure relief can be described as manually and slowly loosening the air release plug I 21, air release plug II 22 of the double filter 10, the overflow valve 20 of the high-pressure oil pump 11, or the pipe connection bolt 8-1 of the manual fuel pre-feed pump 8 to release the pressure, or through automatic pressure relief. For example, the pipe connection bolt 8-1 of the manual fuel pre-feed pump 8 is a spring device, which is automatically opened and closed by pressure. Another example is that the fuel system is equipped with a pressure relief valve, which automatically opens to relieve pressure when the pressure exceeds the set value of 0.3 PMa.

[0042] Such as Figure 4 , the present invention provides measures to avoid excessive pressure during the fuel pumping process of the DC24V electric fuel pre-feed pump 6. The PLC control system controls the fuel pumping of the DC24V electric fuel pre-feed pump 6. Whether the value displayed by the pressure gauge K6 is ≥ 0.3 MPa. If the value is ≥ 0.3 MPa, it indicates that the pressure in the fuel system pipeline is close to the limit value, and the pressurization should be stopped.

[0043] Preferably, the measures to avoid excessive pressure during the fuel pumping process of the DC24V electric fuel pre-feed pump 6 can be described as follows: After the pressure has exceeded the limit value of 0.3 MPa, pressure relief is completed through manual or automatic design to ensure the safety of the fuel pipeline; Manual pressure relief can be described as manually and slowly loosening the air release plug I 21, air release plug II 22 of the double filter 10, the overflow valve 20 of the high-pressure oil pump 11, or the air release bolt 6-1 of the DC24V electric fuel pre-feed pump 6 to release the pressure, or through automatic pressure relief. For example, the air release bolt 6-1 of the DC24V electric fuel pre-feed pump 6 can be an electric or spring design, which is automatically opened and closed by pressure to complete the pressure relief of the fuel pipeline. Another example is that the fuel system is equipped with a pressure relief valve, which automatically opens to relieve pressure when the pressure exceeds the set value of 0.3 PMa.

[0044] Such as Figure 5, the present invention provides a redundant design for the fuel pre-supply system. To ensure better air discharge from the fuel pipeline of the high-speed engine fuel system and prevent "cavitation" of each component, the exhaust can be completed according to the shutdown time before the start-up of the high-speed engine. For an engine with a long shutdown time, the PLC control system is selected to control the DC24V electric fuel pre-supply pump 6 to exhaust, build pressure, and maintain pressure in the fuel system before starting the engine; for an engine with a short shutdown time, manual operation of the manual fuel pre-supply pump 8 is selected to exhaust, build pressure, and maintain pressure in the fuel system before starting the engine.

[0045] As Figure 6 , the redundant design for fuel system exhaust provided by the present invention can be described as follows: After the high-speed engine runs successfully, to avoid incomplete air discharge from the fuel system before operation, an oil-gas separator 15 is designed in the fuel pipeline. The installation height of the oil-gas separator 15 is higher than that of the fuel delivery pump and the fuel filter, and it is located at the highest point of the fuel pipeline. One side of the bottom of the oil-gas separator 15 is provided with an oil-gas separator inlet 15-1, and the oil-gas separator inlet 15-1 is connected to the return oil pipeline of the injector 13 and one end of the fuel return pipe HY5 of the high-pressure oil pump 11 through the fuel return pipe HY4. The other side of the bottom of the oil-gas separator 15 is provided with an oil-gas separator stable oil outlet 15-2, and the top of the oil-gas separator 15 is provided with an oil-gas separator return oil port 15-3. The oil-gas separator return oil port 15-3 is connected to the stop valve I16 through the fuel return pipe ZQ1 to automatically supplement fuel into the oil-gas separator 15. When the oil-gas separator 15 is filled with fuel, due to the action of the gravity of the fuel liquid, it flows through the stable oil outlet 15-2 at the bottom of the oil-gas separator to the low-pressure pipeline layout in front of the high-pressure oil pump 11. The low-pressure pipeline layout in front of the high-pressure oil pump 11 includes a quick-closing valve 2, a check valve 3, a fuel coarse filter K2, a second check valve 5, a low-pressure fuel delivery pump 7, a third check valve 9, a double fuel filter 10, a pressure gauge K6, and an over-guarantee solenoid valve K3, so as to maintain a positive pressure in front of the high-pressure oil pump 11 and prevent gas accumulation, achieving the purpose of automatically discharging the gas in the fuel pipeline.

[0046] Preferably, when the high-speed engine starts and runs, the fuel return pipe HY1 of the high-pressure oil pump 11 is connected to the oil-gas separator inlet 15-1 through the fuel return pipe HY4 of the injector 13 to automatically supplement fuel into the oil-gas separator 15. When the oil-gas separator 15 is filled with fuel, the PLC control system controls the flowmeter K7 to reasonably distribute the excess fuel to flow back to the daily fuel tank 1 through the oil-gas separator return oil port 15-3 at the top of the oil-gas separator 15 through the stop valve I16. The oil-gas separator inlet 15-1 at the bottom of the oil-gas separator 15 is connected to the two-way fuel inlet pipe LY1 through the flowmeter K7 and always remains connected during the operation of the high-speed engine. The flowmeter K7 can adjust the fuel flow rate through the logical programming of the PLC control system; the control technologies of the flowmeter K7 and the PLC control system are mature technologies and will not be elaborated here.

[0047] Preferably, when the high-speed engine stops, since the installation height of the oil-gas separator 15 is higher than that of the low-pressure fuel delivery pump 7 and the double fuel filter 10, the fuel in the oil-gas separator 15 is at the highest position of the entire fuel system and has a height difference with the fuel coarse filter K2, the second one-way valve 5, the DC24V electric fuel pre-supply pump 6, the low-pressure fuel delivery pump 7, the manual fuel pre-supply pump 8, and the double fuel filter 10. Due to the fuel pressure in the oil-gas separator 15, the fuel flows through the fuel return pipe, passes through the flow meter K7, and directly returns to the fuel coarse filter K2 and the double fuel fine filter 10 through the quick-closing valve 2, forming a closed loop. The inlet 19 of the high-pressure oil pump 11 maintains a positive pressure due to the fuel liquid pressure, and the fuel does not fall back in the fuel pipeline at the inlet of the high-pressure oil pump 11, avoiding the accumulation of gas at the inlet 19 of the high-pressure oil pump 11, thus ensuring the normal starting of the diesel engine. The volume of the oil-gas separator 15 can be obtained through bench tests or theoretical calculations of diesel engines with different powers and speeds. Since it is a mature calculation, it will not be elaborated here.

[0048] The present invention realizes the problems of rapid starting of the high-speed engine, rapid elimination of air leakage, inspection of the sealing performance of the fuel system of the high-speed engine, and prevention of excessive pressure during the operation of the pre-supply pump for exhaust through the methods of exhaust and pressure build-up of the pre-supply pump and measures to avoid fuel leakage and excessive pressure, thereby ensuring the smooth starting and initial stable operation of the high-speed engine. It enables the operator to understand potential risks in advance so as to handle them in a timely manner, avoid and prevent equipment damage or safety accidents. Moreover, the pipeline layout is compact, occupying less space, improving the space utilization rate, reducing the number of failure points, being easy to operate, facilitating the maintenance and repair of the fuel system, greatly improving the reliable operation of the high-speed engine, reducing potential safety hazards and construction costs, and also reducing the labor intensity of workers.

[0049] The parts not detailed in the invention are prior art. Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-speed engine fuel pipeline system, characterized in that: It includes a front low-pressure fuel pipeline and a rear fuel pipeline; The front low-pressure fuel pipeline includes a daily-use fuel tank (1), a three-way solenoid valve (4), a DC24V electric fuel pre-feed pump (6), a fuel coarse filter (K2), a low-pressure fuel transfer pump (7), a manual fuel pre-feed pump (8), and a duplex fuel filter (10); The rear fuel pipeline includes a high-pressure oil pump (11), an injector (13), an engine cylinder head (24), an oil-gas separator (15), a flow meter (K7), and a fuel cooler (K1).

2. The fuel pipeline system of a high-speed engine according to claim 1, characterized in that: The daily-use fuel tank (1) is connected in series with a quick shut-off valve (2) through a fuel inlet pipe LY1 in the fuel pipeline. The quick shut-off valve (2) is connected to a first check valve (3) through a fuel inlet pipe LY2. The first check valve (3) is connected to the three-way solenoid valve (4) through a fuel inlet pipe LY3. One end of the three-way solenoid valve (4) is connected to the fuel coarse filter (K2) through a fuel inlet pipe LY4. The other end of the three-way solenoid valve (4) is connected to the DC24V electric fuel pre-feed pump (6) through a fuel inlet pipe LY7. The DC24V electric fuel pre-feed pump (6) is connected to the daily-use fuel tank (1) through a fuel inlet pipe LY8. The fuel coarse filter (K2) is connected to a second check valve (5) through a fuel inlet pipe LY5. The second check valve (5) is respectively connected to the low-pressure fuel transfer pump (7) and the manual fuel pre-feed pump (8) through a fuel inlet pipe LY6. The low-pressure fuel transfer pump (7) is connected to a third check valve (9) through a fuel inlet pipe LY9. The manual fuel pre-feed pump (8) is equipped with a pipe connection bolt (8-1) for automatic or manual air bleeding and oil draining. One end of the third check valve (9) and the manual fuel pre-feed pump (8) is connected to the duplex fuel filter (10) through a fuel inlet pipe LY10. The duplex fuel filter (10) is equipped with an air bleeding plug I (21) and an air bleeding plug II (22) for automatic or manual air bleeding and oil draining. The duplex fuel filter (10) is connected to a pressure gauge (K6) through a fuel inlet pipe LY12. The pressure gauge (K6) is connected to an over-warranty solenoid valve (K3) through a pipeline; The high-pressure oil pump (11) includes an oil inlet (19), a relief valve (20) and an oil outlet (28). The oil inlet (19) is connected to the over-guarantee solenoid valve (K3) through the fuel inlet pipe LY13. The relief valve (20) is connected to the fourth check valve (12) through a fuel pipe. The fourth check valve (12) is connected to the daily-use fuel tank (1) through the fuel return pipe HY5. The oil outlet of the high-pressure oil pump (11) is connected to the fuel injector (13) through the high-pressure pipe HY1. One end of the fuel injector (13) is connected to the engine cylinder head (24). The fuel injector return port (23) in the fuel injector (13) is connected to the fifth check valve (14) through the fuel return pipe HY6. The fifth check valve (14) is connected to the oil-gas separator inlet (15-1) in the oil-gas separator (15) through the fuel return pipe HY4. The fuel return pipe HY4 is connected to the over-guarantee solenoid valve (K3) through the fuel inlet pipe LY11. A sixth check valve (27) is provided on the fuel inlet pipe LY11. The oil-gas separator pressure-stabilized oil outlet (15-2) in the oil-gas separator (15) is connected to the flow meter (K7) through the fuel return pipe ZQ2. The flow meter (K7) is connected to the fuel inlet pipe LY1 through a pipe. The oil-gas separator return port (15-3) in the oil-gas separator (15) is connected to the stop valve I (16) through the fuel return pipe ZQ1. The stop valve I (16) is connected to the fuel cooler (K1) through the fuel return pipe ZQ3. The fuel cooler (K1) is connected to the daily-use fuel tank (1) through the fuel return pipe ZQ4.

3. A high-speed engine fuel pipeline system according to claim 1, characterized in that: The daily-use fuel tank (1) includes a PLC control system, a pressure sensor (17) and a deflation device (18). When the pressure sensor (17) collects signals and the air pressure in the fuel system of the daily-use fuel tank (1) exceeds the limit, the deflation device (18) of the daily-use fuel tank (1) is automatically opened through the logical judgment of the PLC control system and automatically closed after reaching a certain pressure.

4. A high-speed engine fuel pipeline system according to claim 1, characterized in that: The rear fuel pipe further includes a fuel leakage alarm system. The fuel leakage alarm system includes a fuel leakage sensor (K5), a leakage overflow pipe HY3 and a leakage fuel tank (K4). The fuel leakage sensor (K5) is arranged in the connecting pipe HY2. The connecting pipe HY2 is connected to the high-pressure pipe HY1. The other end of the connecting pipe HY2 is connected to the leakage fuel tank (K4) through the leakage overflow pipe HY3.

5. A method for exhausting air and building pressure in a fuel pipeline system of a high-speed engine as described in any one of claims 1-4, characterized in that: It includes an exhaust and pressure-building method realized by the DC24V electric fuel pre-feed pump (6) and an exhaust and pressure-building method realized by the manual fuel pre-feed pump (8).

6. The exhaust and pressure - building method of a fuel pipeline system for a high - speed engine according to claim 5, characterized in that: The method for exhausting air and building pressure of the DC 24V electric fuel pre-feed pump (6) is as follows: When the high-speed engine is in a short-term shutdown state, the PLC control system controls the DC 24V electric fuel pre-feed pump (6) to operate. At the same time, the PLC control system controls the three-way solenoid valve (4) to switch to connect the fuel inlet pipe LY4 and the fuel inlet pipe LY7. On the premise of ensuring that the low-pressure fuel transfer pump (7) is not stuck, keep the DC 24V electric fuel pre-feed pump (6) continuing to pump fuel. Manually and slowly loosen the air release plug (6-1) of the DC 24V electric fuel pre-feed pump (6) until the fuel flowing out has no bubbles, and then manually tighten the air release plug (6-1) of the DC 24V electric fuel pre-feed pump (6). Keep the DC 24V electric fuel pre-feed pump (6) continuing to pump fuel. Manually and slowly loosen the air release plug I (21) and the air release plug II (22) of the double fuel filter (10) until the fuel flowing out has no bubbles, and then manually tighten the air release plug I (21) and the air release plug II (22) of the double fuel filter (10). Keep the DC 24V electric fuel pre-feed pump (6) continuing to pump fuel. Manually and slowly loosen the overflow valve (20) of the high-pressure oil pump (11) until the fuel flowing out has no bubbles, and then manually and slowly tighten the overflow valve (20). After exhausting air from the DC 24V electric fuel pre-feed pump (6), the double fuel filter (10) and the high-pressure oil pump (11), observe that the reading value on the pressure gauge display panel does not jump, indicating that the fuel system has successfully exhausted air. When the reading value on the pressure gauge is 0.3 MPa, it indicates that the pressure has been successfully built up.

7. A method for exhausting air and building pressure in a fuel pipeline system of a high-speed engine according to claim 5, characterized in that: The method for exhausting air and building pressure of the manual fuel pre-feed pump (8) is as follows: When the high-speed engine is in a shutdown state, the PLC control system controls the three-way solenoid valve (4) to switch to connect the fuel inlet pipe LY3 and the fuel inlet pipe LY4. First, slowly loosen the pipe connection bolt (8-1) of the manual fuel pre-feed pump (8), and manually operate the manual fuel pre-feed pump (8) to pump fuel until the fuel flowing out has no bubbles, and then manually tighten the pipe connection bolt (8-1). Manually and slowly loosen the air release plug I (21) and the air release plug II (22) of the double fuel filter (10), and manually operate the manual fuel pre-feed pump (8) to pump fuel until the fuel flowing out has no bubbles. While continuing to manually operate the manual fuel pre-feed pump (8) to pump fuel, manually tighten the air release plug I (21) and the air release plug II (22) of the double fuel filter (10). Manually and slowly loosen the overflow valve (20) of the high-pressure oil pump (11), and manually operate the manual fuel pre-feed pump (8) to pump fuel until the fuel flowing out has no bubbles, and then manually and slowly tighten the overflow valve (20). After exhausting air from the manual fuel pre-feed pump (8), the double fuel filter (10) and the high-pressure oil pump (11), observe that the reading value on the pressure gauge display panel does not jump, indicating that the fuel system has successfully exhausted air. When the reading value on the pressure gauge is 0.3 MPa, it indicates that the pressure has been successfully built up.

8. A pressure stabilization method for a fuel pipeline system of a high-speed engine as described in any one of claims 1 - 4, characterized in that: When the high-speed engine successfully runs and stops, the fuel in the fuel pipeline is still full of fuel. The fuel is collected into the fuel return pipe HY4 through the fuel return pipe HY5 and the fuel return pipe HY6 of the fuel injector (13). The fuel in the fuel return pipe HY4 flows to the inlet (15-1) of the oil-gas separator (15). According to the PLC control logic of the flowmeter (K7), the oil-gas separator (15) distributes the fuel flow and connects part of the fuel to the high-pressure fuel pipe HY1 through the regulated oil outlet (15-2) and returns it to the daily-use fuel tank (1).

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