An aviation engine fuel supply system

Abstract

The present invention discloses an aircraft engine fuel supply system, comprising a normal fuel supply system, a negative pressure fuel tank test system, and a fuel heating system. The normal fuel supply system uses a booster pump to increase pressure, and then uses a pressure reducing valve to reduce pressure, thereby achieving normal fuel supply to the engine. When a negative pressure fuel test is required, the system switches to the negative pressure fuel tank test system by controlling a solenoid valve. A vacuum pump evacuates the negative pressure fuel tank, causing the negative pressure fuel tank to deliver fuel at a specified pressure to the fuel heating system. The fuel then exchanges heat through a heat exchanger in the fuel heating system to heat the fuel before supplying it to the engine. The fuel supply system of the present invention can perform fuel heating and negative pressure fuel testing on the engine, meeting the standards for aircraft engine development, prototyping, and test evaluation, thereby improving the adaptability of the fuel supply system.

Description

Technical Field

[0001] The invention relates to aviation engine ground test equipment, in particular to an aviation engine fuel supply system. Background Art

[0002] The requirements for aircraft engine development, prototyping, and routine test assessments have added fuel heating and fuel negative pressure test requirements, that is, the engine fuel is supplied to the specified temperature through online heating; a fuel negative pressure tank is installed upstream of the fuel online heating device to assess the self-priming oil capacity of the engine suction pump. When using the negative pressure tank test, the fuel needs to be depressurized and then heated through the online heating device to be supplied to the engine. However, the currently commonly used fuel supply systems are directly used to supply fuel to the engine, and the engine cannot be tested for fuel heating and fuel negative pressure. Therefore, there is an urgent need for an oil circuit system that can conveniently realize fuel heating and fuel negative pressure testing of the engine to improve the adaptability of the fuel supply system to meet the requirements of aircraft engine development, prototyping, and routine test assessments. Summary of the Invention

[0003] The present invention provides an aviation engine fuel supply system, which can perform fuel heating and fuel negative pressure tests on the engine, complies with the research and development, prototyping and case test assessment standards of aviation engines, and improves the adaptability of the fuel supply system.

[0004] The technical solutions of the present invention are as follows:

[0005] An aviation engine fuel supply system includes a normal fuel supply system, a negative pressure fuel tank test system and a fuel heating system;

[0006] The normal fuel supply system includes a first filter, a boost pump, a second filter, a third filter, a normally open solenoid valve, and a pressure reducing valve, which are sequentially connected in series via a fuel pipeline; wherein the inlet of the first filter is connected to the oil reservoir, and the outlet of the pressure reducing valve is connected to the fuel heating system, wherein the fuel heating system heats the fuel and outputs it to the engine fuel inlet, and a first temperature sensor is provided at the engine fuel inlet;

[0007] The negative pressure fuel tank test system includes a negative pressure fuel tank and a vacuum pump; the oil inlet at the top of the negative pressure fuel tank is connected to the fuel pipeline between the third filter and the normally open solenoid valve through a first normally closed solenoid valve, and the oil outlet at the bottom of the negative pressure fuel tank is connected to the fuel pipeline between the pressure reducing valve and the fuel heating system through a second normally closed solenoid valve. A first pressure sensor is provided on the top of the negative pressure fuel tank, and a first liquid level sensor is provided on one side; the air inlet of the vacuum pump is connected to the top of the negative pressure fuel tank through an air intake pipeline, and the air outlet of the vacuum pump is connected to an exhaust pipeline.

[0008] The fuel heating system includes a constant temperature oil tank, a circulating oil pump, a heat exchanger, a heater, and a water-cooled radiator; the oil outlet of the constant temperature oil tank is connected to the inlet of the circulating oil pump, the outlet of the circulating oil pump is connected to the medium inlet of the heat exchanger, the medium outlet of the heat exchanger is connected to the inlet of the heater, the outlet of the heater is connected to the medium inlet of the water-cooled radiator, the medium outlet of the water-cooled radiator is connected to the oil inlet of the constant temperature oil tank, the constant temperature oil tank is provided with a second temperature sensor, and a second liquid level sensor is provided on one side; a third temperature sensor is provided between the heat exchanger and the heater, the heat exchange pipeline inlet of the heat exchanger is connected to the outlet of the pressure reducing valve, and the heat exchange pipeline outlet of the heat exchanger is connected to the engine oil inlet.

[0009] In the present invention, the flow process of the normal oil supply system is as follows:

[0010] The fuel flows out of the oil tank and then undergoes a first coarse filtration through the first filter. It is then pressurized by the booster pump and then undergoes a second fine filtration through the second filter and a third fine filtration through the third filter. After three levels of filtration, the fuel meets the fuel cleanliness requirements. A normally open solenoid valve is then installed on the subsequent fuel pipeline to control the opening and closing of the normal oil supply circuit. The oil supply pressure of the normal oil circuit is adjusted by a pressure reducing valve at the outlet of the normally open solenoid valve to ensure that the pressure at the engine oil inlet is within the operating pressure range.

[0011] When a fuel negative pressure test is required, the normally open solenoid valve is energized to cut off the normal oil supply, so that the fuel after three-stage filtration flows into the negative pressure tank test system. After negative pressure adjustment, it flows into the fuel heating system. The fuel heating system heats the fuel to the specified temperature before supplying it to the engine. The first temperature sensor is used to monitor whether the oil temperature has reached the specified temperature, thereby completing the fuel heating and fuel negative pressure test of the engine.

[0012] The principle of the fuel negative pressure test is as follows:

[0013] Before the negative pressure test, the engine is supplied with oil in the normal oil circuit. When the negative pressure test is carried out according to the test requirements, the first normally closed solenoid valve and the second normally closed solenoid valve are first opened (energized), and then the normally open solenoid valve is closed (energized) to complete the negative pressure switch. Then the vacuum pump is started. The vacuum pump uses an inverter to control the motor speed. The inverter is remotely adjusted to enable the vacuum pump to evacuate the negative pressure tank, thereby ensuring that the vacuum degree of the fuel flowing out of the negative pressure tank is within the specified range. Finally, the fuel flows into the fuel heating system for heating and temperature increase. After the fuel temperature reaches the specified temperature, it is supplied to the engine oil inlet;

[0014] Among them, the air extracted by the vacuum pump is discharged through the exhaust pipe, and the first pressure sensor is used to monitor the pressure in the negative pressure tank in real time, so as to realize the control and adjustment of the frequency converter of the vacuum pump to ensure that the vacuum degree of the outflowing fuel reaches the specified range; at the same time, the high and low point positions of the first liquid level sensor on the negative pressure tank are set. When the low point position is reached, the first normally closed solenoid valve of the oil inlet pipe of the negative pressure tank is energized, and the negative pressure tank is filled with oil. When the liquid level reaches the high point position, the first normally closed solenoid valve is de-energized and closed. When there is no need to perform a negative pressure test, the normally open solenoid valve is opened (de-energized) first, and then the two normally closed solenoid valves are closed.

[0015] The process of heating the fuel by the fuel heating system is as follows:

[0016] The fuel is heated in intervals. A constant temperature oil tank, circulating oil pump, heat exchanger, heater and water-cooled radiator are set to form a heat transfer oil circulation loop. Before each test, the second liquid level sensor is used to check whether the heat transfer oil level in the constant temperature oil tank is at the appropriate position. The second liquid level sensor is set with high and low liquid levels. When the oil tank level reaches the low point, the controller alarms and prompts to add heat transfer oil. Otherwise, the filling is stopped. After the inspection is completed, the circulating oil pump is started to flow the heat transfer oil in the constant temperature oil tank through the heat exchanger and then into the heater. The fuel is heated by the heat exchanger and then flows back to the thermostatic oil tank through the water-cooled radiator, completing a circulation of the heat transfer oil. When the second temperature sensor detects that the temperature of the thermostatic oil tank has reached the set value, the fuel heating test can be carried out. At this time, the fuel flows into the heat exchange pipe inlet of the heat exchanger, exchanges heat with the heat transfer oil in the heat exchanger to increase the temperature. After the fuel is heated, it is output to the engine fuel supply port through the heat exchange pipe outlet of the heat exchanger. The first temperature sensor monitors the oil temperature in real time, and the maximum temperature of the output fuel does not exceed 57°C.

[0017] Among them, when the flow rate of fuel inflow is small, the heat exchange amount of the heat exchanger is also small, and the temperature of the heat transfer oil measured by the third temperature sensor is too high. The cooling water electric regulating valve of the water-cooled radiator can be opened to allow the water-cooled radiator to dissipate heat from the heat transfer oil, ensuring that the temperature of the heat transfer oil is within the set range, so that when it flows back to the constant temperature oil tank, the temperature of the constant temperature oil tank is kept within the set range.

[0018] The function of the water-cooled radiator is to lower the temperature of the heat transfer oil entering the heat exchanger when the fuel supply is low flow. When the fuel supply is high flow, the water-cooled radiator stops dissipating heat and turns off the cooling water to ensure that the temperature of the heat transfer oil entering the heat exchanger is within the range to heat the fuel. Another function of the water-cooled radiator is protection, which is to limit the maximum temperature of the heat transfer oil circulation backflow to ensure that the temperature does not exceed the maximum value when the fuel is supplied to the engine.

[0019] The present invention, through the above-mentioned normal fuel supply system, negative pressure fuel tank test system and fuel heating system, can not only supply fuel to the engine normally, but also conveniently perform fuel heating and fuel negative pressure testing. The fuel supply pressure can be adjusted in the normal fuel supply system, the vacuum degree of the fuel can be adjusted in the negative pressure fuel tank test system, and the fuel supply temperature can be adjusted in the fuel heating system. Through the fuel supply system of the present invention, it can be ensured that the fuel is output to the engine fuel supply port while meeting the test standards.

[0020] Furthermore, an overflow valve and a regulating valve are connected in parallel at both ends of the booster pump.

[0021] The regulating valve is used to adjust the boost range of the boost valve. The overflow valve is a hydraulic pressure control valve that acts as a constant pressure overflow for the boost pump, stabilizes the output pressure of the boost pump, and acts as an unloading and safety protection valve.

[0022] Furthermore, a first pressure gauge is provided at the outlet of the second filter, and a second pressure gauge is provided at the inlet of the fuel heating system.

[0023] The first pressure gauge is installed at the outlet of the boost pump to monitor the boost pressure of the fuel to prevent excessive boost and to adjust the output pressure of the boost pump in time to meet the pre-valve pressure requirement of the subsequent pressure reducing valve; the second pressure gauge is used to monitor the fuel pressure after the pressure reducing valve is reduced to ensure that the fuel is within the appropriate supply pressure range.

[0024] Among them, since the engine's fuel supply needs to be tested under negative pressure and heated, a pressure transmitter with a measuring range of -90kPa-500kPa can be installed at the engine's fuel supply port. It is called a fuel supply pressure transmitter and can accurately display the actual pressure of the fuel after negative pressure and heating.

[0025] Furthermore, a fire damper is provided on the fuel pipeline between the second filter and the third filter, and an emergency stop solenoid valve is provided on the fuel pipeline communicating between the pressure reducing valve and the fuel heating system.

[0026] Fire dampers and emergency stop solenoid valves are installed on the fuel pipeline to ensure the safety of the fuel supply system. In an emergency, the fire dampers and emergency stop solenoid valves will lose power and close, which can cut off the fuel supply in time to ensure safety and avoid accidents.

[0027] Furthermore, an oil drain port with a valve is provided on the fuel pipeline connecting the fire damper and the third filter.

[0028] Generally, the oil drain port is set at the high point of the fuel pipeline. The oil drain port is used to exhaust air and remove the air in the pipeline to reduce impurities in the fuel.

[0029] Furthermore, a two-position three-way solenoid valve is provided on the fuel pipeline connecting the fire damper and the second filter. The two outlets of the two-position three-way solenoid valve are respectively connected to a mass flow meter and a first turbine flow meter. The outlets of the two flow meters are both connected to the inlet of the fire damper, and a second turbine flow meter is provided on the fuel pipeline connecting the pressure reducing valve and the emergency stop solenoid valve.

[0030] The fuel flow is measured using a mass flow meter or a first turbine flow meter, which is switched by a remote two-position three-way solenoid valve. To improve measurement accuracy, during the engine development phase, a second turbine flow meter is connected in series after the pressure reducing valve and before the engine fuel inlet to verify the flow rate. The flow rate can be verified by comparing the errors of the two flow meters before and after the pressure reducing valve to determine the accuracy of the flow meter measurement.

[0031] Furthermore, a one-way valve is provided at one end of the air intake pipe connected to the vacuum pump, and the air intake pipe is connected to an air supply pipe, the inlet of the air supply pipe is connected to the air source, and a stop valve is provided on the air supply pipe.

[0032] When the vacuum pump is evacuating the negative pressure oil tank, the one-way valve can allow gas to be extracted from the negative pressure oil tank, but can prevent external gas from entering the negative pressure oil tank, thereby ensuring the vacuum degree of the negative pressure oil tank and preventing external gas from contaminating the negative pressure oil tank.

[0033] A tee is opened in the air intake pipe to add an air supply pipe. An adjustment switch and a filter can also be set on the air supply pipe to ensure the cleanliness of the supplied air. The air supply pipe is used to remove the vacuum in the negative pressure tank when the vacuum is too high or the test is stopped. Before the test, manually open the stop valve and add air to the upper part of the negative pressure tank through the air supply pipe to remove the vacuum in the negative pressure tank. Then close the stop valve to complete the air supply and start the vacuum pump to evacuate the air to ensure the normal conduct of the negative pressure test.

[0034] Furthermore, the outlet of the exhaust pipe is connected to a water tank, and the outlet is placed below the liquid level of the water tank, and an exhaust port is provided on the top of the water tank.

[0035] The air outlet of the vacuum pump is connected to a water tank filled with cleaning fluid. The gas containing oil molecules vaporized in the negative pressure tank can be purified by the water tank and then discharged into the room through the exhaust port, thus ensuring the cleanliness of the air in the test workshop.

[0036] Furthermore, a first sewage pipe with a valve is provided at the bottom of the negative pressure oil tank, and the sewage of the negative pressure oil tank can be drained and cleaned when no test is carried out.

[0037] Furthermore, an air filter is provided at the top air outlet of the constant temperature oil tank to filter and discharge the heat conduction oil and gas in the constant temperature oil tank to avoid polluting the workshop. At the same time, a second drain pipe with a valve is provided at the bottom of the constant temperature oil tank. When no test is carried out, the drain pipe can drain and clean the constant temperature oil tank.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The aircraft engine fuel supply system of the present invention consists of a normal fuel supply system, a negative pressure fuel tank test system and a fuel heating system. The present invention can not only provide normal fuel supply to the engine, but also conveniently perform fuel heating and fuel negative pressure testing, conforming to the research and development, prototyping and test assessment standards of aircraft engines, and improving the adaptability of the fuel supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of an aviation engine fuel supply system according to the present invention;

[0041] Figure 2 This is a schematic diagram of a normal oil supply system;

[0042] Figure 3 It is a schematic diagram of the negative pressure tank test system;

[0043] Figure 4 Schematic diagram of the fuel heating system.

[0044] In the figure: first filter 1, boost pump 2, second filter 3, third filter 4, normally open solenoid valve 5, pressure reducing valve 6, first temperature sensor 7, negative pressure oil tank 8, vacuum pump 9, first normally closed solenoid valve 10, second normally closed solenoid valve 11, first pressure sensor 12, first liquid level sensor 13, intake pipe 14, exhaust pipe 15, constant temperature oil tank 16, circulating oil pump 17, heat exchanger 18, heater 19, water cooling radiator 20, second temperature sensor 21, first Second liquid level sensor 22, third temperature sensor 23, overflow valve 24, regulating valve 25, first pressure gauge 26, second pressure gauge 27, fire damper 28, emergency stop solenoid valve 29, one-way valve 30, air supply pipeline 31, stop valve 32, water tank 33, exhaust port 34, first sewage pipe 35, air filter 36, second sewage pipe 37, oil drain port 38, two-position three-way solenoid valve 39, mass flowmeter 40, first turbine flowmeter 41, second turbine flowmeter 42. DETAILED DESCRIPTION

[0045] The drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate the embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent actual product dimensions. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted from the drawings. The positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0046] Example 1:

[0047] like Figures 1-4 As shown, an aircraft engine fuel supply system includes a normal fuel supply system, a negative pressure fuel tank test system and a fuel heating system;

[0048] The normal fuel supply system includes a first filter 1, a boost pump 2, a second filter 3, a third filter 4, a normally open solenoid valve 5, and a pressure reducing valve 6, which are sequentially connected in series via a fuel pipeline. The inlet of the first filter 1 is connected to the oil reservoir, and the outlet of the pressure reducing valve 6 is connected to the fuel heating system. The fuel heating system heats the fuel and outputs it to the engine fuel inlet. A first temperature sensor 7 is provided at the engine fuel inlet.

[0049] The negative pressure fuel tank test system includes a negative pressure fuel tank 8 and a vacuum pump 9. The oil inlet at the top of the negative pressure fuel tank 8 is connected to the fuel pipeline between the third filter 4 and the normally open solenoid valve 5 through a first normally closed solenoid valve 10. The oil outlet at the bottom of the negative pressure fuel tank 8 is connected to the fuel pipeline between the pressure reducing valve 6 and the fuel heating system through a second normally closed solenoid valve 11. A first pressure sensor 12 is provided on the top of the negative pressure fuel tank 8, and a first liquid level sensor 13 is provided on one side. The air inlet of the vacuum pump 9 is connected to the top of the negative pressure fuel tank 8 through an air intake pipe 14, and the air outlet of the vacuum pump 9 is connected to an exhaust pipe 15.

[0050] The fuel heating system includes a constant temperature oil tank 16, a circulating oil pump 17, a heat exchanger 18, a heater 19, and a water-cooled radiator 20; the oil outlet of the constant temperature oil tank 16 is connected to the inlet of the circulating oil pump 17, the outlet of the circulating oil pump 17 is connected to the medium inlet of the heat exchanger 18, the medium outlet of the heat exchanger 18 is connected to the inlet of the heater 19, the outlet of the heater 19 is connected to the medium inlet of the water-cooled radiator 20, and the medium outlet of the water-cooled radiator 20 is connected to the oil inlet of the constant temperature oil tank 16. The constant temperature oil tank 16 is provided with a second temperature sensor 21, and a second liquid level sensor 22 is provided on one side; a third temperature sensor 23 is provided between the heat exchanger 18 and the heater 19, the inlet of the heat exchange pipe of the heat exchanger 18 is connected to the outlet of the pressure reducing valve 6, and the outlet of the heat exchange pipe of the heat exchanger 18 is connected to the oil inlet of the engine.

[0051] In the present invention, the flow process of the normal oil supply system is as follows:

[0052] The fuel flows out of the oil reservoir and then undergoes a first coarse filtration through the first filter 1. It is then pressurized by the booster pump 2, and then undergoes a second fine filtration through the second filter 3 and a third fine filtration through the third filter 4. After three levels of filtration, the fuel meets the fuel cleanliness requirements. Then, a normally open solenoid valve 5 is installed on the subsequent fuel pipeline to control the opening and closing of the normal oil supply circuit. The oil supply pressure of the normal oil circuit is adjusted by a pressure reducing valve 6 at the outlet of the normally open solenoid valve 5 to ensure that the pressure at the engine oil inlet is within the operating pressure range.

[0053] When a fuel negative pressure test is required, the normally open solenoid valve 5 is energized to cut off the normal oil supply, so that the fuel after three-stage filtration flows into the negative pressure tank test system. After negative pressure adjustment, it flows into the fuel heating system, which heats the fuel to the specified temperature before supplying it to the engine. The first temperature sensor 7 is used to monitor whether the oil temperature has reached the specified temperature, thereby completing the fuel heating and fuel negative pressure test of the engine.

[0054] The principle of the fuel negative pressure test is as follows:

[0055] Before the negative pressure test, the engine is supplied with oil in the normal oil circuit. When the negative pressure test is carried out according to the test requirements, the first normally closed solenoid valve 10 and the second normally closed solenoid valve 11 are first opened (energized), and then the normally open solenoid valve 5 is closed (energized) to complete the negative pressure switch. Then the vacuum pump 9 is started. The vacuum pump 9 uses an inverter to control the motor speed. The inverter is remotely adjusted to enable the vacuum pump 9 to evacuate the negative pressure tank 8, thereby ensuring that the vacuum degree of the fuel flowing out of the negative pressure tank 8 is within the specified range. Finally, the fuel flows into the fuel heating system for heating and temperature increase. After the fuel temperature reaches the specified temperature, it is supplied to the engine oil inlet;

[0056] Among them, the air extracted by the vacuum pump 9 is discharged through the exhaust pipe 15, and the first pressure sensor 12 is used to monitor the pressure in the negative pressure tank 8 in real time, so as to realize the control and adjustment of the frequency converter of the vacuum pump 9 to ensure that the vacuum degree of the outflowing fuel reaches the specified range; at the same time, the high and low point positions of the first liquid level sensor 13 on the negative pressure tank 8 are set. When the low point position is reached, the first normally closed solenoid valve 10 of the oil inlet pipe of the negative pressure tank 8 is energized, and the negative pressure tank 8 is filled with oil. When the liquid level reaches the high point position, the first normally closed solenoid valve 10 is de-energized and closed. When there is no need to perform a negative pressure test, the normally open solenoid valve 5 is first opened (de-energized), and then the two normally closed solenoid valves are closed.

[0057] The process of heating the fuel by the fuel heating system is as follows:

[0058] The fuel is heated in intervals. A thermostatic oil tank 16, a circulating oil pump 17, a heat exchanger 18, a heater 19 and a water-cooled radiator 20 are provided to form a heat transfer oil circulation loop. Before each test, the second liquid level sensor 22 is used to check whether the heat transfer oil level in the thermostatic oil tank 16 is at an appropriate position. The second liquid level sensor 22 is set with a high point and a low point. When the oil tank level reaches the low point, the controller alarms and prompts to add heat transfer oil. Otherwise, the filling is stopped. After the inspection is completed, the circulating oil pump 17 is started to transfer the heat transfer oil in the thermostatic oil tank 16 through the heat exchanger 18 and then to the heat transfer oil cooler. The fuel enters the heater 19 for heating, and then flows back to the thermostatic oil tank 16 through the water-cooled radiator 20, completing a circulation of the heat transfer oil. When the second temperature sensor 21 detects that the temperature of the thermostatic oil tank 16 has reached the set value, the fuel heating test can be carried out. At this time, the fuel flows into the heat exchange pipe inlet of the heat exchanger 18, exchanges heat with the heat transfer oil in the heat exchanger 18 to increase the temperature. After the fuel is heated, it is output to the engine fuel supply port through the heat exchange pipe outlet of the heat exchanger 18. The first temperature sensor 7 monitors the oil temperature in real time, and the maximum temperature of the output fuel does not exceed 57°C.

[0059] Among them, when the flow rate of fuel inflow is small, the heat exchange amount of the heat exchanger 18 is also small, and the temperature of the heat transfer oil measured by the third temperature sensor 23 is too high. The cooling water electric regulating valve of the water-cooled radiator 20 can be opened to allow the water-cooled radiator 20 to dissipate heat from the heat transfer oil, ensuring that the temperature of the heat transfer oil is within the set range, so that when the heat transfer oil flows back to the thermostatic oil tank 16, the temperature of the thermostatic oil tank 16 is maintained within the set range.

[0060] The function of the water-cooled radiator 20 is to reduce the temperature of the heat transfer oil entering the heat exchanger 18 when the fuel supply is low. When the fuel supply is high, the water-cooled radiator 20 stops dissipating heat and turns off the cooling water to ensure that the temperature of the heat transfer oil entering the heat exchanger 18 is within a certain range to heat the fuel. Another function of the water-cooled radiator 20 is a protective function, that is, to limit the maximum temperature of the heat transfer oil circulation backflow to ensure that the temperature of the fuel does not exceed the maximum value when it is supplied to the engine.

[0061] In this embodiment, the normal fuel supply system can be remotely switched to the negative pressure fuel tank test system to test the self-priming ability of the engine fuel pump, so that the fuel pressure at the engine inlet can be adjusted within the range of (-20kPa) to (-40kPa) (pressure gauge).

[0062] The present invention, through the above-mentioned normal fuel supply system, negative pressure fuel tank test system and fuel heating system, can not only supply fuel to the engine normally, but also conveniently perform fuel heating and fuel negative pressure testing. The fuel supply pressure can be adjusted in the normal fuel supply system, the vacuum degree of the fuel can be adjusted in the negative pressure fuel tank test system, and the fuel supply temperature can be adjusted in the fuel heating system. Through the fuel supply system of the present invention, it can be ensured that the fuel is output to the engine fuel supply port while meeting the test standards.

[0063] In this embodiment, a precision pressure reducing valve 6 is used to adjust the oil supply pressure, which has high accuracy and stable pressure when the flow rate changes greatly. The main technical parameters of the engine oil supply are as follows:

[0064] 1) Oil supply pressure: (30~150) kPa,

[0065] 2) Maximum oil flow: 815L / h

[0066] 3) The fuel cleanliness and mechanical impurity standards at the engine inlet meet the requirements of Grade 7 in GJB420B.

[0067] Because the oil tank outlet of the oil depot is typically less than 3 meters away from the engine's oil inlet, there's flow resistance in the intermediate pipeline, meaning the fuel pressure at the engine's oil inlet is less than 30kPa. Therefore, the normal fuel supply system requires pressurization, which is then reduced to a suitable fuel pressure for the engine using a precision pressure reducing valve 6. A diaphragm-type pressure reducing valve 6 can be used, with the upstream pressure requirement being less than 400kPa and the downstream pressure within an adjustable range of 30kPa-200kPa.

[0068] In this embodiment, a relief valve 24 and a regulating valve 25 are connected in parallel at both ends of the boost pump 2. The regulating valve 25 is used to adjust the boost range of the boost valve 2. The relief valve 24 is a hydraulic pressure control valve that provides a constant pressure relief for the boost pump 2, stabilizing the output pressure of the boost pump 2 and providing load relief and safety protection. After the fuel is boosted by the boost pump 2, the fuel supply pressure can be adjusted within a range of 30 to 150 kPa under conditions where the fuel flow rate to the engine varies significantly.

[0069] In this embodiment, a first pressure gauge 26 is provided at the outlet of the second filter 3, and a second pressure gauge 27 is provided at the inlet of the fuel heating system. The first pressure gauge 26 installed at the outlet of the boost pump 2 monitors the fuel boost pressure to prevent over-boosting and promptly adjust the output pressure of the boost pump 2 to meet the downstream pressure requirement of the pressure reducing valve 6. The second pressure gauge 27 monitors the fuel pressure after the pressure reducing valve 6, ensuring that the fuel remains within the appropriate supply pressure range.

[0070] Among them, since the engine's fuel supply needs to be tested under negative pressure and heated, a pressure transmitter (not shown in the figure) with a measuring range of -90kPa-500kPa can be installed at the engine's fuel supply port. It is called a fuel supply pressure transmitter to accurately display the actual pressure of the fuel after negative pressure and heating.

[0071] In this embodiment, a fire damper 28 is installed on the fuel pipeline between the second filter 3 and the third filter 4, and an emergency stop solenoid valve 29 is installed on the fuel pipeline connecting the pressure reducing valve 6 and the fuel heating system. The installation of fire dampers 28 and emergency stop solenoid valves 29 on the fuel pipeline is to ensure the safety of the fuel supply system. In an emergency, the fire damper 28 and emergency stop solenoid valves 29 will close upon power failure, promptly cutting off the fuel supply and ensuring safety and preventing accidents.

[0072] In this embodiment, since the test bench is already in operation, it is necessary to increase the self-priming capacity of the engine fuel pump. The effective volume of the low-level fuel tank is not less than 1000L. If a low-level fuel tank is used, pit construction is inconvenient, and the solution of sinking the low-level fuel tank in the test bench is not feasible. Therefore, this embodiment adopts the solution of negative pressure fuel tank 8. The negative pressure fuel tank 8 is equipped with a first liquid level sensor 13, which is used to control the liquid level of negative pressure fuel tank 8 to fluctuate within a certain range, ensuring that the volume of the upper space of negative pressure fuel tank 8 is constant, and thus ensuring that the negative pressure value fluctuates within a certain range, meeting the test requirements.

[0073] In this embodiment, a frequency converter is used to control the vacuum pump 9 to adjust the vacuum level of the negative pressure oil tank 8, thereby solving the problem of unstable vacuum control. The main technical requirements are as follows:

[0074] 1) Working medium: No. 3 jet fuel (GB6537-2006), No. 5 jet fuel (GJB560A-1997);

[0075] 2) Fuel supply: (0~500)kg / h;

[0076] 3) Oil inlet temperature: normal temperature;

[0077] 4) Fuel tank capacity: ≥1500L;

[0078] 5) Oil tank inlet pressure: (0~0.35)MPa;

[0079] 6) Vacuum degree: 0~-40kPa (gauge pressure, adjustable);

[0080] 7) Pressure control accuracy: ±200Pa;

[0081] 8) System leakage rate: 9×10-6Pa·m3 / s;

[0082] 9) Vacuum pressure control accuracy: ±0.2kPa.

[0083] Two pressure transmitters (not shown in the figure) can be installed on the negative pressure oil tank 8, with a measuring range of -90kPa-500kPa. One transmitter transmits the signal to the frequency converter of the vacuum pump 9. The frequency converter adjusts the speed of the vacuum pump 9 according to the vacuum pressure signal to ensure that the vacuum degree in the negative pressure oil tank 8 fluctuates within the specified range. The other transmitter transmits the signal to the digital collector (not shown in the figure), which is used to display the real-time pressure of the negative pressure oil tank 8 in the background.

[0084] In this embodiment, a one-way valve 30 is provided at one end of the air intake pipe 14 connected to the vacuum pump 9. An air supply pipe 31 is also connected to the air intake pipe 14. The inlet of the air supply pipe 31 is connected to the gas source, and a shut-off valve 32 is provided on the air supply pipe 31. When the vacuum pump 9 evacuates the negative pressure tank 8, the one-way valve 30 allows gas to be drawn out of the negative pressure tank 8 while preventing outside air from entering the negative pressure tank 8. This ensures the vacuum level of the negative pressure tank 8 while preventing outside air from contaminating the negative pressure tank 8. A three-way connection is provided in the air intake pipe 14 to add the air supply pipe 31. An adjustment switch and a filter (not shown) may also be provided on the air supply pipe 31 to ensure the cleanliness of the incoming air. The air supply pipe 31 is used to remove the vacuum level of the negative pressure tank 8 when the vacuum level is too high or when the test is stopped. Before the test, manually open the stop valve 32, replenish air to the upper part of the negative pressure oil tank 8 through the air supply pipe 31, eliminate the vacuum degree of the negative pressure oil tank 8, then close the stop valve 32, complete the air supply, and then start the vacuum pump 9 to evacuate the vacuum to ensure the normal progress of the negative pressure test.

[0085] In this embodiment, the outlet of exhaust pipe 15 is connected to a water tank 33, with the outlet positioned below the liquid level of the water tank 33. An exhaust port 34 is provided at the top of the water tank 33. The outlet of vacuum pump 9 is connected to the water tank 33, which contains cleaning fluid. This allows the gas containing vaporized oil molecules within negative pressure oil tank 8 to be purified by the water tank 33 and then discharged into the room through exhaust port 34, ensuring the cleanliness of the air in the test workshop.

[0086] In this embodiment, a first drain pipe 35 with a valve is provided at the bottom of the negative pressure oil tank 8, so that the negative pressure oil tank 8 can be drained and cleaned when no test is being performed.

[0087] In this embodiment, the fuel flow rate varies greatly, so the fuel can be heated at intervals to ensure fuel cleanliness requirements while solving the problem of high temperature control requirements. Therefore, the main technical indicators of the fuel heating system are as follows:

[0088] 1) Working medium: No. 3 jet fuel (GB6537-2006), No. 5 jet fuel (GJB560A-1997);

[0089] 2) Oil inlet temperature: 0℃~40℃;

[0090] 3) Oil supply temperature steady-state control accuracy: ±1°C;

[0091] 4) Dynamic control accuracy of fuel supply temperature: ±4°C (fuel flow rate change rate is 4L / s);

[0092] 5) Maximum oil flow rate: 20L / min;

[0093] 6) Maximum fuel temperature: 57°C;

[0094] 7) Fuel flow resistance: ≤500Pa.

[0095] After the fuel is decompressed, it is heated to the specified temperature through the fuel heating system before being supplied to the engine. The fuel heating system is modular in design and can be integrated into one. The fuel heating system is connected in series to the normal fuel supply system, and the oil outlet of the fuel heating system is connected to the oil inlet of the engine.

[0096] In this embodiment, an air filter 36 is provided at the top air outlet of the constant temperature oil tank 16 to filter and discharge the heat conduction oil and gas in the constant temperature oil tank 16 to avoid polluting the workshop. At the same time, a second drain pipe 37 with a valve is provided at the bottom of the constant temperature oil tank 16. When no test is being carried out, the drain pipe can drain and clean the constant temperature oil tank 16.

[0097] During normal fuel supply, first connect the output port at the end of the normal fuel supply system to the engine through the engine fuel inlet hose, remotely open the fire damper 28 and the emergency stop solenoid valve 29, start the boost pump 2, manually adjust the outlet pressure of the boost pump 2 to the specified value, and then adjust the pressure reducing valve 6 to ensure that the pressure flowing to the engine fuel inlet is the specified value. The remaining solenoid valves shall not be energized, and the fuel heating system shall not be started, so that the normal fuel supply system can supply fuel to the engine normally.

[0098] When conducting negative pressure and temperature rise tests, the three solenoid valves are energized at the same time, that is, the first normally closed solenoid valve 10 and the second normally closed solenoid valve 11 are opened, and the normally open solenoid valve 5 is closed. Then, the stop valve 32 of the air supply pipe 31 is opened, and the negative pressure oil tank 8 is connected to the atmosphere for air supply and vacuum removal. Then, the stop valve 32 is closed, and then the vacuum pump 9 is remotely started and the working range of the vacuum pump 9 is set. When the vacuum degree reaches the specified value, the vacuum pump 9 reduces the working speed. When the first pressure sensor 12 of the negative pressure oil tank 8 detects that the pressure measurement value in the tank is less than the specified value, , the vacuum pump 9 increases the working speed, but because the position of the engine oil inlet is generally higher than the negative pressure tank 8 and the pipeline flow resistance, there is a difference between the engine oil supply pressure and the pressure of the negative pressure tank 8. Therefore, the pressure of the negative pressure tank 8 is fine-tuned according to the actual oil supply pressure of the engine, so that the fuel flowing out of the negative pressure tank 8 meets the negative pressure requirements to ensure that the engine oil inlet pressure is within the required range. Finally, the fuel heating system is started, and the fuel output from the negative pressure tank 8 is heated to a suitable temperature by the fuel heating system to supply to the engine, thereby completing the negative pressure and temperature rise test.

[0099] The aircraft engine fuel supply system of the present invention consists of a normal fuel supply system, a negative pressure fuel tank test system and a fuel heating system. The present invention can not only provide normal fuel supply to the engine, but also conveniently perform fuel heating and fuel negative pressure testing, conforming to the research and development, prototyping and test assessment standards of aircraft engines, and improving the adaptability of the fuel supply system.

[0100] Example 2:

[0101] This embodiment is similar to the embodiment 1, except that, in this embodiment, an oil drain port 38 with a valve is provided on the fuel pipe connecting the fire damper 28 and the third filter 4 .

[0102] The oil drain port 38 is set at a high point of the fuel pipeline. The oil drain port is used to exhaust air and remove air in the pipeline to reduce impurities in the fuel.

[0103] Example 3:

[0104] This embodiment is similar to Example 1, except that, in this embodiment, a two-position three-way solenoid valve 39 is provided on the fuel pipeline connecting the fire damper 28 and the second filter 3, and the two outlets of the two-position three-way solenoid valve 39 are respectively connected to a mass flowmeter 40 and a first turbine flowmeter 41, and the outlets of the two flowmeters are both connected to the inlet of the fire damper 28, and a second turbine flowmeter 42 is provided on the fuel pipeline connecting the pressure reducing valve 6 and the emergency stop solenoid valve 29.

[0105] The fuel flow is measured using a mass flow meter 40 or a first turbine flow meter 41, which is switched by using a remote two-position three-way solenoid valve 39. To improve the accuracy of the measurement, during the engine development phase, a second turbine flow meter 42 is connected in series after the pressure reducing valve 6 and before the engine oil inlet to verify the flow. The flow can be verified by comparing the errors of the two flow meters before and after the pressure reducing valve 6 to determine the accuracy of the flow meter measurement.

[0106] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. An aviation engine fuel supply system, characterized in that: Including normal fuel supply system, negative pressure fuel tank test system and fuel heating system; The normal fuel supply system comprises a first filter (1), a boost pump (2), a second filter (3), a third filter (4), a normally open solenoid valve (5), and a pressure reducing valve (6) which are sequentially connected in series via a fuel pipeline; wherein the inlet of the first filter (1) is connected to the oil reservoir, and the outlet of the pressure reducing valve (6) is connected to the fuel heating system, the fuel heating system heats the fuel and outputs it to the engine fuel inlet, and a first temperature sensor (7) is provided at the engine fuel inlet; The negative pressure oil tank test system comprises a negative pressure oil tank (8) and a vacuum pump (9); the oil inlet at the top of the negative pressure oil tank (8) is connected to the fuel pipeline between the third filter (4) and the normally open solenoid valve (5) through a first normally closed solenoid valve (10); the oil outlet at the bottom of the negative pressure oil tank (8) is connected to the fuel pipeline between the pressure reducing valve (6) and the fuel heating system through a second normally closed solenoid valve (11); a first pressure sensor (12) is provided at the top of the negative pressure oil tank (8), and a first liquid level sensor (13) is provided on one side; the air inlet of the vacuum pump (9) is connected to the top of the negative pressure oil tank (8) through an air inlet pipeline (14), and the air outlet of the vacuum pump (9) is connected to an exhaust pipeline (15); The fuel heating system comprises a constant temperature oil tank (16), a circulating oil pump (17), a heat exchanger (18), a heater (19), and a water-cooled radiator (20); the oil outlet of the constant temperature oil tank (16) is communicated with the inlet of the circulating oil pump (17), the outlet of the circulating oil pump (17) is communicated with the medium inlet of the heat exchanger (18), the medium outlet of the heat exchanger (18) is communicated with the inlet of the heater (19), and the outlet of the heater (19) is communicated with the water-cooled radiator (20). The inlet of the water-cooled radiator (20) is connected, the outlet of the water-cooled radiator (20) is connected to the oil inlet of the thermostatic oil tank (16), the thermostatic oil tank (16) is provided with a second temperature sensor (21), and a second liquid level sensor (22) is provided on one side; a third temperature sensor (23) is provided between the heat exchanger (18) and the heater (19), the inlet of the heat exchange pipeline of the heat exchanger (18) is connected to the outlet of the pressure reducing valve (6), and the outlet of the heat exchange pipeline of the heat exchanger (18) is connected to the oil inlet of the engine.

2. The aviation engine fuel supply system according to claim 1, characterized in that: An overflow valve (24) and a regulating valve (25) are connected in parallel at both ends of the boosting pump (2).

3. The aircraft engine fuel supply system according to claim 1, characterized in that: A first pressure gauge (26) is provided at the outlet of the second filter (3), and a second pressure gauge (27) is provided at the inlet of the fuel heating system.

4. The aviation engine fuel supply system according to claim 1, characterized in that: A fire damper (28) is provided on the fuel pipeline between the second filter (3) and the third filter (4), and an emergency stop solenoid valve (29) is provided on the fuel pipeline communicating between the pressure reducing valve (6) and the fuel heating system.

5. The aircraft engine fuel supply system according to claim 4, characterized in that: An oil drain port (38) with a valve is provided on the fuel pipeline communicating with the fire damper (28) and the third filter (4).

6. The aircraft engine fuel supply system according to claim 4, characterized in that: A two-position three-way solenoid valve (39) is provided on the fuel pipeline connecting the fire damper (28) and the second filter (3), and the two outlets of the two-position three-way solenoid valve (39) are respectively connected to a mass flow meter (40) and a first turbine flow meter (41), and the outlets of the two flow meters are both connected to the inlet of the fire damper (28), and a second turbine flow meter (42) is provided on the fuel pipeline connecting the pressure reducing valve (6) and the emergency stop solenoid valve (29).

7. The aircraft engine fuel supply system according to claim 1, characterized in that: A one-way valve (30) is provided at one end of the air intake pipe (14) connected to the vacuum pump (9), and an air supply pipe (31) is connected to the air intake pipe (14). The inlet of the air supply pipe (31) is connected to an air source, and a stop valve (32) is provided on the air supply pipe (31).

8. The aircraft engine fuel supply system according to claim 1, characterized in that: The outlet of the exhaust pipe (15) is connected to a water tank (33), and the outlet is located below the liquid level of the water tank (33). The top of the water tank (33) is provided with an exhaust port (34).

9. The aircraft engine fuel supply system according to claim 1, characterized in that: A first sewage discharge pipe (35) with a valve is provided at the bottom of the negative pressure oil tank (8).

10. The aircraft engine fuel supply system according to claim 1, characterized in that: An air filter (36) is provided at the top air port of the constant temperature oil tank (16), and a second sewage pipe (37) with a valve is provided at the bottom.

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