A low-temperature fuel system for an aircraft engine test bench

Abstract

The present invention provides a low-temperature fuel system for an aircraft engine test bench, which relates to the technical field of fuel systems and includes: using a mass flow meter to determine and control the release of room-temperature fuel from an aviation fuel storage tank, filtering and regulating it, obtaining flow data of a first regulated fuel, calibrating it, and then inputting it into the aircraft engine test bench to obtain a first ignition test operating condition; when the operating condition result is unstable, controlling the release of room-temperature fuel from the aviation fuel storage tank, performing coarse and fine filtration and temperature and pressure regulation to obtain a second regulated fuel, then using a mass flow meter to determine the flow data of the second regulated fuel, calibrating it, and then inputting it into the aircraft engine test bench. The output of low-temperature fuel is achieved by simulating the compression-expansion heat exchange of a chiller, and the supply and regulation functions of room-temperature and low-temperature fuel are achieved using an oil pump, a regulating valve, and a relief valve. This saves test time and reduces the cost of using the test bench, which is conducive to improving the probability of successful engine start-up in a real plateau environment.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel systems, and in particular to a low-temperature fuel system for an aviation engine test bench. Background Art

[0002] Aerospace technology is one of the fastest-growing fields of science and technology in humanity's pursuit of understanding and transforming nature, with the greatest impact on people's lives. It is also a key indicator of a country's comprehensive national strength. Aircraft engines, as the heart of aircraft, are a key driving force behind the development of the aviation industry. The primary function of aircraft engine fuel supply systems is to provide clean fuel that meets specific pressure and flow requirements to aircraft engines operating in complex environmental conditions, ensuring successful engine starts.

[0003] my country has a vast territory with high terrain in the west and low terrain in the east. The ground temperature varies greatly depending on the region, seasons and day and night. Especially in plateau environments, engine starting faces huge challenges.

[0004] Therefore, the present invention provides a low-temperature fuel system for an aviation engine test bench, which is used to simulate the actual state of fuel in a low-temperature environment on a plateau, and is beneficial to improving the probability of successful engine start-up in a real plateau environment. Summary of the Invention

[0005] The present invention provides a low-temperature fuel system for an aviation engine test bench, which is used to achieve the output of low-temperature fuel by simulating the compression-expansion heat exchange of a chiller. An oil pump, a regulating valve, and a relief valve are used to realize the supply and regulation functions of normal temperature and low-temperature fuel. While saving test time, it also reduces the cost of using the test bench, which is conducive to improving the probability of successful engine starting in a real plateau environment.

[0006] The present invention provides a low-temperature fuel system for an aircraft engine test bench, comprising:

[0007] Normal temperature fuel supply module: used for controlling the aviation fuel storage tank to release a first preset amount of normal temperature fuel after receiving a first start signal of the aircraft engine, and filtering and regulating the fuel to obtain a first regulated fuel;

[0008] Working condition acquisition module: used to determine the flow data of the first regulated fuel using a mass flow meter and calibrate it, and then input it into the aircraft engine test bench to obtain the first ignition test working condition;

[0009] Switching module: used to obtain and analyze the first ignition test condition, and if the test condition result is unstable, send a second start signal to the low-temperature fuel supply module;

[0010] Low-temperature fuel supply module: After receiving the second start signal, it controls the aviation fuel storage tank to release a second preset amount of room-temperature fuel and performs coarse and fine filtration and temperature and pressure adjustment to obtain the second regulated fuel. The flow data of the second regulated fuel is then determined by a mass flow meter and calibrated before being input into the aircraft engine test bench.

[0011] Preferably, the normal temperature fuel supply module includes:

[0012] Signal analysis unit: used to obtain and output the first start-up signal of the aircraft engine and the fuel demand information of the aircraft flight in real time;

[0013] A first flow direction unit is configured to, based on the obtained fuel demand information of the aviation flight, open the fuel switch valve to control the aviation kerosene storage tank to release a first preset amount of first fuel, and then open the first switch valve to allow the first fuel to flow to the normal temperature fuel supply pipeline;

[0014] The first filter unit is used to filter the first fuel through the first coarse oil filter, then use the corresponding normal temperature oil pump to boost the pressure, and then use the first fine oil filter to filter the first fuel to obtain the first filtered fuel;

[0015] The first pressure regulating unit is used to pressurize the normal temperature fuel by the normal temperature oil pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve is combined with a pressure transmitter to return the excess normal temperature fuel through the overflow valve to obtain the first regulated fuel.

[0016] The first reflux processing unit is used to return the refluxed normal temperature fuel to the aviation kerosene storage tank through the return oil main pipe, and to determine the mass flow of the refluxed fuel through the calibrated mass flow meter installed at the return oil main pipe.

[0017] Preferably, the operating condition acquisition module includes:

[0018] A flow calculation unit is configured to determine the mass flow of the first regulated fuel using a mass flow meter to obtain first flow data;

[0019] Calibration unit: used to determine a first temperature and a first pressure of a first regulated fuel using a temperature sensor and a pressure transmitter, and then obtain first fuel information in combination with the first flow data and calibrate the first regulated fuel;

[0020] Working condition acquisition unit: used to deliver the first regulated fuel to the aircraft engine test bench to obtain the first ignition test working condition.

[0021] Preferably, the switching module includes:

[0022] A working condition analysis unit is configured to analyze the first ignition test working condition and, if the aircraft engine fails to start successfully, estimate the corresponding fuel pre-state information when the engine is successfully started;

[0023] The sending unit is used to determine and receive the fuel pre-state information and transmit it together with the second start signal to the low-temperature fuel supply module.

[0024] Preferably, the operating condition analysis unit includes:

[0025] Analysis block: used to analyze the first ignition test condition and obtain the key parameter change curve during the engine startup process. If the engine is successfully started, the key parameters corresponding to the successful startup moment are stored in the ignition test database;

[0026] The estimation block is used to determine the turbine work done by the gas generated by the combustion of the first regulated fuel on the entire turbine blades based on the first fuel information when the engine fails to start successfully. The turbine work is calculated as follows:

[0027]

[0028] Where L represents the turbine work; n represents the total number of turbine blades; It is expressed as the average work done on the turbine by the gas generated during the combustion of each kilogram of fuel in a change period T; v is expressed as the gas mass flow rate; F is expressed as the gas pressure; r1 and r2 are the hub and rim radii of the turbine blades respectively; w is expressed as the turbine speed; δ is expressed as the friction loss factor caused by the movement of the turbine wheel;

[0029] The least squares method is used to establish a linear regression relationship between turbine power and engine starting conditions to obtain estimated power. Then, based on the linear regression relationship between the estimated power and fuel temperature, fuel pressure, and fuel mass flow rate, combined with the correlation coefficient, the preset low temperature and preset fuel pressure of the fuel are estimated.

[0030] Preferably, the fuel pre-state information refers to the fuel temperature and fuel pressure required for the successful start of the aircraft engine.

[0031] Preferably, the low-temperature fuel supply module includes:

[0032] Absorption unit: used to obtain and output the second start signal and fuel pre-state information output by the switching module in real time;

[0033] A second flow direction unit is configured to, based on the obtained fuel pre-state information, open the fuel switch valve to control the aviation kerosene storage tank to release a second preset amount of second fuel, and then open the second switch valve to allow the second fuel to flow to the low-temperature fuel supply pipeline;

[0034] The second filter unit is used to filter the second fuel through the second coarse oil filter, then use the corresponding low-temperature oil pump to boost the pressure, and then use the second fine oil filter to filter the second fuel to obtain the second filtered fuel;

[0035] Temperature regulating unit: used to heat the second filtered fuel oil to a preset low temperature through a heat exchanger, and then enter the cold oil storage tank. A temperature sensor and a pressure transmitter are installed on the check valve through which the second filtered fuel oil passes to display the fuel state before heat exchange. A temperature sensor is installed on the cold oil storage tank to display the low temperature fuel temperature.

[0036] The second pressure regulating unit is used to pressurize the second filtered fuel after it is boosted by the low-temperature fuel pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve and the pressure transmitter are used to return the excess second filtered fuel through the overflow valve to obtain the second regulated fuel, which is then transmitted to the aircraft engine test bench.

[0037] The second reflux processing unit is used to return the excess second filtered fuel to the aviation kerosene storage tank through the return oil main pipe, and determine the mass flow of the reflux fuel through the calibrated mass flow meter installed at the return oil main pipe.

[0038] Preferably, the temperature regulating unit comprises:

[0039] Refrigeration-refrigerant heat exchange block: The chiller starts the compressors of the corresponding temperatures according to the input preset low temperature, and exchanges heat between the refrigerant and the refrigerant in the evaporator through evaporation compression and isobaric expansion;

[0040] Adjustment block: adjusts the temperature of the coolant through the electric heater, and displays the coolant temperature through the corresponding temperature sensor after adjustment;

[0041] Carrier refrigerant-fuel heat exchange block: The carrier refrigerant and fuel are exchanged in the heat exchanger. After the carrier refrigerant exchanges heat with the fuel, it takes away the heat of the fuel. The temperature after heat exchange is displayed by the temperature sensor, and then it enters the evaporator again to exchange heat with the carrier refrigerant. The cycle is repeated in sequence to continuously produce low-temperature fuel.

[0042] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0043] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 This is a structural diagram of a low-temperature fuel system of an aircraft engine test bench according to an embodiment of the present invention;

[0046] Figure 2 This is a flow simulation diagram of a low-temperature fuel system of an aircraft engine test bench in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0048] The embodiment of the present invention provides a low temperature fuel system for an aircraft engine test bench, such as Figure 1 As shown, including:

[0049] Normal temperature fuel supply module: used to control the aviation fuel storage tank to release a first preset amount of normal temperature fuel after receiving the first start signal of the aircraft flight engine, and filter and regulate it to obtain first regulated fuel;

[0050] Working condition acquisition module: used to determine the flow data of the first regulated fuel using a mass flow meter and calibrate it, and then input it into the aircraft engine test bench to obtain the first ignition test working condition;

[0051] Switching module: used to obtain and analyze the first ignition test condition, and if the test condition result is unstable, send a second start signal to the low-temperature fuel supply module;

[0052] Low-temperature fuel supply module: After receiving the second start signal, it controls the aviation fuel storage tank to release a second preset amount of room-temperature fuel and performs coarse and fine filtration and temperature and pressure adjustment to obtain the second regulated fuel. The flow data of the second regulated fuel is then determined by a mass flow meter and calibrated before being input into the aircraft engine test bench.

[0053] In this embodiment, the first start signal refers to an activation signal of the aircraft flight engine, which is used to quickly transmit to the normal temperature fuel supply module to control the aviation fuel storage tank to release preset fuel; the first preset amount is set in advance based on the fuel demand for starting the aircraft engine; the first regulated fuel is obtained by coarse and fine filtering and pressure regulation of the first preset amount of normal temperature fuel released from the aviation fuel storage tank.

[0054] In this embodiment, the mass flow meter is used to measure the mass flow rate of fuel as one of the indicators for evaluating engine performance, and is generally installed at the fuel return main pipe, the normal temperature fuel supply pipeline and the low temperature fuel supply pipeline; the flow data refers to the mass of fuel passing through the closed pipeline per unit time measured by the mass flow meter; the aircraft engine test bench is used for ground ignition tests, that is, the engine is fixed to a device using a test device; the first ignition test condition refers to the situation where the aircraft engine is started; the second start signal refers to the signal sent to the low temperature fuel supply module when the result of the first ignition test condition is unstable, that is, when the engine fails to start, which is used to realize automatic switching of the supply module.

[0055] In this embodiment, the second preset amount is set in advance based on the fuel pre-state information obtained after analyzing the first ignition test condition in the switching module, where the fuel pre-state information refers to the fuel temperature and fuel pressure required for a successful engine start; the second regulated fuel is obtained by coarse and fine filtering and temperature and pressure adjustment of the second preset amount of room temperature fuel released from the aviation fuel storage tank.

[0056] The beneficial effects of the above technical solution are: by simulating the compression and expansion heat exchange of the chiller to achieve the output of low-temperature fuel, using the oil pump, regulating valve, and overflow valve to achieve normal temperature and low-temperature fuel supply and regulation functions, saving test time while reducing the cost of using the test bench, which is conducive to increasing the probability of successful engine start-up in a real plateau environment.

[0057] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the normal-temperature fuel supply module includes:

[0058] Signal analysis unit: used to obtain and output the first start-up signal of the aircraft engine and the fuel demand information of the aircraft flight in real time;

[0059] A first flow direction unit is configured to, based on the obtained fuel demand information of the aviation flight, open the fuel switch valve to control the aviation kerosene storage tank to release a first preset amount of first fuel, and then open the first switch valve to allow the first fuel to flow to the normal temperature fuel supply pipeline;

[0060] The first filter unit is used to filter the first fuel through the first coarse oil filter, then use the corresponding normal temperature oil pump to boost the pressure, and then use the first fine oil filter to filter the first fuel to obtain the first filtered fuel;

[0061] The first pressure regulating unit is used to pressurize the normal temperature fuel by the normal temperature oil pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve is combined with a pressure transmitter to return the excess normal temperature fuel through the overflow valve to obtain the first regulated fuel.

[0062] The first reflux processing unit is used to return the refluxed normal temperature fuel to the aviation kerosene storage tank through the return oil main pipe, and to determine the mass flow of the refluxed fuel through the calibrated mass flow meter installed at the return oil main pipe.

[0063] In this embodiment, the first start signal refers to the activation signal of the aircraft flight engine, which is used to quickly transmit to the normal temperature fuel supply module to control the aviation fuel storage tank to release the preset fuel; the fuel demand information mainly refers to the fuel usage and fuel pressure index; the first preset amount is set in advance based on the fuel demand information; the first fuel refers to the first preset amount of fuel released from the aviation kerosene storage tank; the first switch valve refers to a one-way valve that controls the flow of fuel to the normal temperature fuel supply pipeline, and has the function of preventing fuel backflow; the first coarse oil filter is used for initial filtration of the first fuel; the first fine oil filter is used for re-filtering the first fuel after filtering and pressurization to ensure that impurities in the fuel will not affect the normal operation of the oil pump; the first filtered fuel is the fuel obtained after coarse and fine filtration of the first fuel.

[0064] In this embodiment, the normal temperature oil pump is used to pressurize the future oil into high-pressure fuel; the first regulated fuel is the fuel remaining after the first filtered fuel is pressurized by the normal temperature oil pump, and the excess normal temperature fuel is returned through the overflow valve using the regulating valve and the pressure sensor; the regulating valve is used to adjust the fuel to meet the needs of the aircraft engine; the pressure sensor is used to sense the fuel pressure; the overflow valve is used to; the calibrated mass flow meter is used to measure the mass flow rate of the returned fuel; the mass flow rate refers to the mass of fuel passing through the closed pipeline per unit time measured by the mass flow meter.

[0065] In this embodiment, for example, there is a flow simulation diagram of a low-temperature fuel system of an aircraft engine test bench, such as Figure 2 As shown:

[0066] Step 11: Open the on-off valve V7, and the aviation kerosene, i.e., fuel, flows out of the aviation kerosene storage tank A1;

[0067] Step 12: Open the on-off valve V1, and the fuel flows to the normal temperature fuel supply pipe G1, and is filtered through the coarse oil filter F1;

[0068] Step 13: After the fuel is pressurized by the oil pump P1 at room temperature, it is filtered through the fine oil filter F3;

[0069] Step 14: The fuel passes through the check valve V3 and flows to the regulating valve V5, which adjusts the fuel to meet the requirements of the aircraft engine. Excess fuel flows back through the relief valve V7 and enters the normal temperature return oil pipe G3. The check valve V3 prevents the fuel from flowing back to the oil inlet. A temperature sensor / pressure transmitter is installed after the check valve V3.

[0070] Step 15: The normal temperature return oil returns to the aviation kerosene storage tank A1 through the return oil main pipe G5, passing through the calibrated mass flow meter M3 along the way.

[0071] The beneficial effect of the above technical solution is: based on the fuel demand information of aviation flight, the room temperature fuel is filtered using a coarse and fine oil filter, and then the excess room temperature fuel is returned through the overflow valve using a regulating valve and a pressure transmitter, thereby effectively obtaining the first regulated fuel that meets the fuel pressure index of the aircraft engine.

[0072] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the operating condition acquisition module includes:

[0073] A flow calculation unit is configured to determine the mass flow of the first regulated fuel using a mass flow meter to obtain first flow data;

[0074] Calibration unit: used to determine a first temperature and a first pressure of a first regulated fuel using a temperature sensor and a pressure transmitter, and then obtain first fuel information in combination with the first flow data and calibrate the first regulated fuel;

[0075] Working condition acquisition unit: used to deliver the first regulated fuel to the aircraft engine test bench to obtain the first ignition test working condition.

[0076] In this embodiment, the mass flowmeter is used to measure the mass flow rate of fuel as one of the indicators for evaluating engine performance and is installed in the normal temperature fuel supply pipeline. The first regulated fuel refers to the fuel remaining after the first filtered fuel is pressurized by the normal temperature oil pump and the excess normal temperature fuel is returned through the overflow valve using the regulating valve and the pressure sensor. The first flow data refers to the fuel mass of the first regulated fuel passing through the normal temperature fuel supply pipeline per unit time, as measured by the mass flowmeter.

[0077] In this embodiment, the first temperature is obtained by using a temperature sensor installed in the normal temperature oil supply pipeline; the first pressure is obtained by using a pressure transmitter installed in the normal temperature oil supply pipeline; the first fuel information is composed of the first temperature, the first pressure and the first flow data; the aircraft engine test bench is used for ground ignition tests, that is, the engine is fixed to a device using a test device; the first ignition test condition refers to the situation where the aircraft engine is started.

[0078] The beneficial effects of the above technical solution are: determining the fuel information of the first regulated fuel and calibrating it by using a mass flow meter, a temperature sensor and a pressure transmitter; delivering the calibrated first regulated fuel to the aircraft engine test bench to obtain the first ignition test condition.

[0079] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the switching module includes:

[0080] A working condition analysis unit is configured to analyze the first ignition test working condition and, if the aircraft engine fails to start successfully, estimate the corresponding fuel pre-state information when the engine is successfully started;

[0081] The sending unit is used to determine and receive the fuel pre-state information and transmit it together with the second start signal to the low-temperature fuel supply module.

[0082] In this embodiment, the first ignition test condition refers to the test condition of the ignition and start-up of the aircraft engine; the fuel pre-state information refers to the preset low temperature and preset pressure of the fuel required for the successful start-up of the aircraft engine; the second start signal refers to the signal sent to the low-temperature fuel supply module when the result of the first ignition test condition is unstable, that is, when the engine fails to start, to realize automatic switching of the supply module; wherein, the low-temperature fuel supply module is used to simulate the fuel supply of the aircraft engine in a plateau environment.

[0083] The beneficial effect of the above technical solution is: by analyzing the first ignition test conditions, when the aircraft engine fails to start successfully, the corresponding fuel pre-state information when the engine is successfully started can be effectively estimated, laying a data support for the start of aircraft engines in plateau environments.

[0084] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the operating condition analysis unit includes:

[0085] Analysis block: used to analyze the first ignition test condition and obtain the key parameter change curve during the engine startup process. If the engine is successfully started, the key parameters corresponding to the successful startup moment are stored in the ignition test database;

[0086] The estimation block is used to determine the turbine work done by the gas generated by the combustion of the first regulated fuel on the entire turbine blades based on the first fuel information when the engine fails to start successfully. The turbine work is calculated as follows:

[0087]

[0088] Where L represents the turbine work; n represents the total number of turbine blades; It is expressed as the average work done on the turbine by the gas generated during the combustion of each kilogram of fuel in a change period T; v is expressed as the gas mass flow rate; F is expressed as the gas pressure; r1 and r2 are the hub and rim radii of the turbine blades respectively; w is expressed as the turbine speed; δ is expressed as the friction loss factor caused by the movement of the turbine wheel;

[0089] The least squares method is used to establish a linear regression relationship between turbine power and engine starting conditions to obtain estimated power. Then, based on the linear regression relationship between the estimated power and fuel temperature, fuel pressure, and fuel mass flow rate, combined with the correlation coefficient, the preset low temperature and preset fuel pressure of the fuel are estimated.

[0090] In this embodiment, the first ignition test condition refers to the test condition of the ignition start-up of the aircraft engine; the key parameter change curve refers to the change trend of the fuel flow and fuel supply pressure data during the start-up of the aircraft engine; the key parameters refer to the current fuel temperature, the current fuel flow and the current fuel supply pressure; the first fuel information is composed of the first temperature, the first pressure and the first flow data.

[0091] In this embodiment, the least squares method is used to obtain the linear regression relationship in order to ensure that the optimal solution is unique and the calculation is convenient; the linear regression relationship refers to the influence relationship between the engine starting condition and the turbine work; the turbine work refers to the actual work output on the turbine shaft after the gas generated during the combustion of each kilogram of fuel expands in the turbine; the estimated work is the turbine work required for the successful start of the aircraft engine based on the analysis of the linear regression relationship between the turbine work and the engine starting condition established by the least squares method; the preset low temperature and the preset fuel pressure are obtained based on the linear regression relationship between the estimated work and the fuel temperature, fuel pressure, and fuel mass flow rate; the correlation coefficient actually refers to the degree of intrinsic connection between the estimated work and the fuel temperature, fuel pressure, and fuel mass flow rate.

[0092] The beneficial effects of the above technical solution are: by analyzing the first ignition test conditions, when the start is successful, the key parameters of the engine start time are obtained and stored; if the start is successful, the preset low temperature and preset fuel pressure of the fuel when the engine is successfully started are estimated in combination with linear regression, providing a basis for the successful start of aircraft engines in plateau environments.

[0093] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the low-temperature fuel supply module includes:

[0094] Absorption unit: used to obtain and output the second start signal and fuel pre-state information output by the switching module in real time;

[0095] A second flow direction unit is configured to, based on the obtained fuel pre-state information, open the fuel switch valve to control the aviation kerosene storage tank to release a second preset amount of second fuel, and then open the second switch valve to allow the second fuel to flow to the low-temperature fuel supply pipeline;

[0096] The second filter unit is used to filter the second fuel through the second coarse oil filter, then use the corresponding low-temperature oil pump to boost the pressure, and then use the second fine oil filter to filter the second fuel to obtain the second filtered fuel;

[0097] Temperature regulating unit: used to heat the second filtered fuel oil to a preset low temperature through a heat exchanger, and then enter the cold oil storage tank. A temperature sensor and a pressure transmitter are installed on the check valve through which the second filtered fuel oil passes to display the fuel state before heat exchange. A temperature sensor is installed on the cold oil storage tank to display the low temperature fuel temperature.

[0098] The second pressure regulating unit is used to pressurize the second filtered fuel after it is boosted by the low-temperature fuel pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve and the pressure transmitter are used to return the excess second filtered fuel through the overflow valve to obtain the second regulated fuel, which is then transmitted to the aircraft engine test bench.

[0099] The second reflux processing unit is used to return the excess second filtered fuel to the aviation kerosene storage tank through the return oil main pipe, and determine the mass flow of the reflux fuel through the calibrated mass flow meter installed at the return oil main pipe.

[0100] In this embodiment, the second start signal refers to the signal sent to the low-temperature fuel supply module when the result of the first ignition test condition is unstable, that is, when the engine fails to start, and is used to realize automatic switching of the supply module; the fuel pre-state information refers to the preset low temperature and preset pressure of the fuel required for the successful start of the aircraft engine; the second filtered fuel refers to the fuel after coarse and fine filtration of the second fuel.

[0101] In this embodiment, the heat exchanger is used to heat the second filtered fuel into low-temperature fuel at a preset low temperature; the preset low temperature is obtained based on the linear regression relationship between the estimated power and the fuel temperature, combined with the corresponding correlation coefficient; the cold oil storage tank is used to store the low-temperature fuel at the preset low temperature after heat exchange by the heat exchanger; and the check valve is used to prevent the fuel from flowing back.

[0102] In this embodiment, the cryogenic oil pump is used to pressurize the cryogenic fuel to a high-pressure cryogenic fuel that meets the fuel pressure index of the aircraft engine; the overflow valve is used to control the excess cryogenic fuel to flow to the return oil main pipe; the second regulated fuel refers to the fuel remaining after the second filtered fuel is pressurized by the cryogenic oil pump and the excess cryogenic fuel is returned through the overflow valve using the regulating valve and the pressure sensor; the calibrated mass flowmeter is used to measure the mass flow rate of the returned cryogenic fuel.

[0103] In this embodiment, for example, there is a flow simulation diagram of a low-temperature fuel system of an aircraft engine test bench, such as Figure 2 As shown:

[0104] Step 21: Open the on-off valve V2, and the fuel flows to the low-temperature fuel supply pipe G2, and is filtered through the coarse oil filter F2;

[0105] Step 22: After the fuel is pressurized by the low-temperature oil pump P2, it is filtered through the fine oil filter F4;

[0106] Step 23: The fuel passes through the check valve V4 and flows to the heat exchanger H2, where the normal temperature fuel is heated to low temperature fuel. The fuel then enters the cold oil storage tank A2. A temperature sensor and pressure transmitter are installed after the check valve V4 to display the fuel status before the heat exchange. A temperature sensor is installed on the cold oil storage tank A2 to display the low temperature fuel temperature.

[0107] Step 24: The low-temperature fuel is pressurized by the low-temperature fuel pump P3 and flows to the regulating valve V6 to adjust the fuel to meet the requirements of the aircraft engine. The excess fuel is returned through the overflow valve V8 and enters the low-temperature return oil pipeline G4.

[0108] Step 24: The low-temperature return oil returns to the aviation kerosene storage tank A1 through the return oil main pipe G5, passing through the calibrated mass flow meter M3 along the way;

[0109] Step 25: The regulated fuel enters the aircraft engine test bench after being calibrated by the mass flow meter M2, temperature sensor, and pressure transmitter.

[0110] In this embodiment, a low-temperature fuel system for an aircraft engine test bench further includes:

[0111] The verification module is used to verify the filtration of the second coarse oil filter and the second fine oil filter before the actual use of the low-temperature fuel system of the aircraft engine test bench. It specifically includes:

[0112] Performing a first filtration on the fuel to be verified based on the second coarse oil filter to obtain a first oil to be analyzed;

[0113] Performing a second filtration on the fuel to be verified based on a second fine oil filter to obtain a second oil to be analyzed;

[0114] Performing a third filtration on the fuel to be verified based on the second coarse oil filter and the second fine oil filter in sequence to obtain a third fuel to be analyzed;

[0115] Performing impurity detection on the fuel to be verified, the first oil to be analyzed, the second oil to be analyzed, and the third oil to be analyzed, respectively, and obtaining a first vector, a second vector, a third vector, and a fourth vector, respectively;

[0116] Calculating a first filter coefficient between the first vector, the second vector, and the standard vector; calculating a second filter coefficient between the first vector, the third vector, and the standard vector; and calculating a third filter coefficient between the first vector, the fourth vector, and the standard vector;

[0117]

[0118] Among them, W0 i1 W2 represents the standard value of the i1th detection impurity in the standard vector; i1Represents the second detection value of the \(i_1\)th detected impurity in the second vector; \(W1\) i1 Represents the first detection value of the \(i_1\)th detected impurity in the first vector; \(D1\) represents the first filtration coefficient;

[0119]

[0120] Among them, \(W0\) i1 Represents the standard value of the \(i_1\)th detected impurity in the standard vector; \(W3\) i1 Represents the second detection value of the \(i_1\)th detected impurity in the third vector; \(W1\) i1 Represents the first detection value of the \(i_1\)th detected impurity in the first vector; \(D2\) represents the second filtration coefficient;

[0121]

[0122] Among them, \(W0\) i1 Represents the standard value of the \(i_1\)th detected impurity in the standard vector; \(W4\) i1 Represents the second detection value of the \(i_1\)th detected impurity in the fourth vector; \(W1\) i1 Represents the first detection value of the \(i_1\)th detected impurity in the first vector; \(D3\) represents the third filtration coefficient;

[0123] If \(D3\geq D03\), at this time, it is determined that the first filtration coefficient, the second filtration coefficient, and the third filtration coefficient meet the filtration constraint standard, then it is determined that the corresponding second coarse oil filter and the second fine oil filter are qualified;

[0124] If \(D3 < D03\), if \(D1\geq D01\) and \(D2\geq D02\), at this time, according to Lock the oil filter to be optimized, and obtain the first new oil filter to replace the corresponding oil filter to be optimized;

[0125] If \(D3 < D03\), if \(D1 < D01\) and \(D2\geq D02\), at this time, according to \(D1\), lock the oil filter to be optimized, and according to Determine the first number to be set, and replace the oil filter to be optimized with the consistent new oil filter according to the first number to be set;

[0126] If \(D3 < D03\), if \(D1\geq D01\) and \(D2 < D02\), at this time, according to \(D2\), lock the oil filter to be optimized, and according to Determine the second number to be set, and replace the oil filter to be optimized with the consistent new oil filter according to the second number to be set;

[0127] If \(D3 < D03\), if \(D1 < D01\) and \(D2 < D02\), at this time, according to \(D1\) and \(D2\), lock the oil filter to be optimized, and obtain the corresponding second new oil filter to replace the consistent oil filter to be optimized respectively;

[0128] Wherein, D01 represents the first standard coefficient; D02 represents the second standard coefficient; D03 represents the third standard coefficient, and D01>D02>D03, max represents the maximum value symbol; [] represents the rounding symbol.

[0129] In this embodiment, since the presence of impurities in the fuel and the differences in the impurities may seriously affect the fuel system and cause malfunctions, the oil filter needs to be verified before the fuel system is put into actual use.

[0130] In this embodiment, different oils to be analyzed are obtained after filtering based on related oil filters. Therefore, the filtering results of the second coarse oil filter, the second fine oil filter, and the combined filtering results of the second coarse oil filter and the second fine oil filter are obtained separately, which facilitates comprehensive analysis to determine the oil filter that needs to be processed and ensures the effectiveness of the filtration.

[0131] In this embodiment, the standard vector refers to the composition of different impurities in the standard fuel provided by the fuel system, such as mechanical impurities, and the standard values ​​of the different impurities in the corresponding standard vector are pre-set.

[0132] The oil filters are verified individually and in combination using the fuel to be verified, and the oil filters that need to be replaced and the number of replacements are determined by calculating and comparing the filtration coefficients. This facilitates subsequent actual use and can avoid fuel system failures caused by oil filter anomalies.

[0133] The beneficial effect of the above technical solution is: based on the fuel pre-state information, the room temperature fuel is filtered using a coarse and fine oil filter, and then heat exchanged using a heat exchanger. In combination with a regulating valve and a pressure transmitter, the excess low-temperature fuel is returned through the overflow valve, effectively obtaining a second regulated fuel that meets the fuel pressure indicators of the aircraft engine.

[0134] An embodiment of the present invention provides a low-temperature fuel system for an aircraft engine test bench, wherein the temperature regulating unit includes:

[0135] Refrigeration-refrigerant heat exchange block: The chiller starts the compressors of the corresponding temperatures according to the input preset low temperature, and exchanges heat between the refrigerant and the refrigerant in the evaporator through evaporation compression and isobaric expansion;

[0136] Adjustment block: adjusts the temperature of the coolant through the electric heater, and displays the coolant temperature through the corresponding temperature sensor after adjustment;

[0137] Carrier refrigerant-fuel heat exchange block: The carrier refrigerant and fuel are exchanged in the heat exchanger. After the carrier refrigerant exchanges heat with the fuel, it takes away the heat of the fuel. The temperature after heat exchange is displayed by the temperature sensor, and then it enters the evaporator again to exchange heat with the carrier refrigerant. The cycle is repeated in sequence to continuously produce low-temperature fuel.

[0138] In this embodiment, the refrigerant has a low boiling point and is used to absorb the heat of the refrigerant in the evaporator to convert the low-temperature, low-pressure liquid into a high-temperature, low-pressure gas; the evaporation compression and isobaric expansion method refers to using a compressor to pressurize the high-temperature, low-pressure gas into a high-temperature, high-pressure gas, and then perform constant-pressure heat exchange with cooling water to take away the heat of the gas refrigerant and convert it into a low-temperature, high-pressure gas, and then convert the low-temperature, high-pressure gas into a low-temperature, low-pressure liquid through an expansion valve.

[0139] In this embodiment, for example, there is a flow simulation diagram of a low-temperature fuel system of an aircraft engine test bench, such as Figure 2 As shown:

[0140] Step 31: The chiller starts the compressors of the corresponding temperatures according to the input set temperature, and exchanges heat between the refrigerant and the secondary coolant in the evaporator H1 through evaporation compression and isobaric expansion.

[0141] Step 32: The coolant temperature is adjusted by the electric heater D1; after adjustment, the coolant temperature is displayed by the temperature sensor T5;

[0142] Step 33: The refrigerant and the fuel are heat exchanged in the heat exchanger H2 to produce low-temperature fuel. After the refrigerant and the fuel are heat exchanged, the heat of the fuel is taken away. The temperature sensor displays the temperature after the heat exchange and the refrigerant enters the evaporator H1 again to exchange heat with the refrigerant. The cycle continues in sequence to continuously produce low-temperature fuel.

[0143] The beneficial effect of the above technical solution is: by utilizing the chiller and circulating heat exchange in the form of evaporation compression and isobaric expansion to achieve effective output of low-temperature fuel, providing an effective supply function for the low-temperature fuel supply module.

[0144] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A low-temperature fuel system for an aircraft engine test bench, characterized in that: include: Normal temperature fuel supply module: used for controlling the aviation fuel storage tank to release a first preset amount of normal temperature fuel after receiving a first start signal of the aircraft engine, and filtering and regulating the fuel to obtain a first regulated fuel; Working condition acquisition module: used to determine the flow data of the first regulated fuel using a mass flow meter and calibrate it, and then input it into the aircraft engine test bench to obtain the first ignition test working condition; Switching module: used to obtain and analyze the first ignition test condition, and if the test condition result is unstable, send a second start signal to the low-temperature fuel supply module; Low-temperature fuel supply module: After receiving the second start signal, it controls the aviation fuel storage tank to release a second preset amount of room-temperature fuel and performs coarse and fine filtration and temperature and pressure adjustment to obtain the second regulated fuel. The flow data of the second regulated fuel is then determined by a mass flow meter and calibrated before being input into the aircraft engine test bench.

2. The low-temperature fuel system for an aircraft engine test bench according to claim 1, characterized in that: The normal temperature fuel supply module includes: Signal analysis unit: used to obtain and output the first start-up signal of the aircraft engine and the fuel demand information of the aircraft flight in real time; A first flow direction unit is configured to, based on the obtained fuel demand information of the aviation flight, open the fuel switch valve to control the aviation kerosene storage tank to release a first preset amount of first fuel, and then open the first switch valve to allow the first fuel to flow to the normal temperature fuel supply pipeline; The first filter unit is used to filter the first fuel through the first coarse oil filter, then use the corresponding normal temperature oil pump to boost the pressure, and then use the first fine oil filter to filter the first fuel to obtain the first filtered fuel; The first pressure regulating unit is used to pressurize the normal temperature fuel by the normal temperature oil pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve is combined with a pressure transmitter to return the excess normal temperature fuel through the overflow valve to obtain the first regulated fuel. The first reflux processing unit is used to return the refluxed normal temperature fuel to the aviation kerosene storage tank through the return oil main pipe, and to determine the mass flow of the refluxed fuel through the calibrated mass flow meter installed at the return oil main pipe.

3. The low-temperature fuel system for an aircraft engine test bench according to claim 1, characterized in that: The working condition acquisition module includes: A flow calculation unit is configured to determine the mass flow of the first regulated fuel using a mass flow meter to obtain first flow data; Calibration unit: used to determine a first temperature and a first pressure of a first regulated fuel using a temperature sensor and a pressure transmitter, and then obtain first fuel information in combination with the first flow data and calibrate the first regulated fuel; Working condition acquisition unit: used to deliver the first regulated fuel to the aircraft engine test bench to obtain the first ignition test working condition.

4. The low-temperature fuel system for an aircraft engine test bench according to claim 1, characterized in that: The switching module includes: A working condition analysis unit is configured to analyze the first ignition test working condition and, if the aircraft engine fails to start successfully, estimate the corresponding fuel pre-state information when the engine is successfully started; The sending unit is used to determine and receive the fuel pre-state information and transmit it together with the second start signal to the low-temperature fuel supply module.

5. The low-temperature fuel system for an aircraft engine test bench according to claim 4, characterized in that: The operating condition analysis unit includes: Analysis block: used to analyze the first ignition test condition and obtain the key parameter change curve during the engine startup process. If the engine is successfully started, the key parameters corresponding to the successful startup moment are stored in the ignition test database; The estimation block is used to determine the turbine work done by the gas generated by the combustion of the first regulated fuel on the entire turbine blades based on the first fuel information when the engine fails to start successfully. The turbine work is calculated as follows: Where, Expressed as turbine work; Expressed as the total number of turbine blades; It is expressed as the average work done on the turbine by the gas generated during the combustion of each kilogram of fuel in one change period T; It is expressed as gas mass flow rate; F is expressed as gas pressure; and They represent the hub and rim radii of the turbine blades respectively; Expressed as turbine speed; It is expressed as the friction loss factor caused by the movement of the turbine wheel; The least squares method is used to establish a linear regression relationship between turbine power and engine starting conditions to obtain estimated power. Then, based on the linear regression relationship between the estimated power and fuel temperature, fuel pressure, and fuel mass flow rate, combined with the correlation coefficient, the preset low temperature and preset fuel pressure of the fuel are estimated.

6. The low-temperature fuel system for an aircraft engine test bench according to claim 4, characterized in that: The fuel pre-state information refers to the fuel temperature and fuel pressure required for the successful start of the aircraft engine.

7. The low-temperature fuel system for an aircraft engine test bench according to claim 1, characterized in that: The low-temperature fuel supply module includes: Absorption unit: used to obtain and output the second start signal and fuel pre-state information output by the switching module in real time; A second flow direction unit is configured to, based on the obtained fuel pre-state information, open the fuel switch valve to control the aviation kerosene storage tank to release a second preset amount of second fuel, and then open the second switch valve to allow the second fuel to flow to the low-temperature fuel supply pipeline; The second filter unit is used to filter the second fuel through the second coarse oil filter, then use the corresponding low-temperature oil pump to boost the pressure, and then use the second fine oil filter to filter the second fuel to obtain the second filtered fuel; Temperature regulating unit: used to heat the second filtered fuel oil to a preset low temperature through a heat exchanger, and then enter the cold oil storage tank. A temperature sensor and a pressure transmitter are installed on the check valve through which the second filtered fuel oil passes to display the fuel state before heat exchange. A temperature sensor is installed on the cold oil storage tank to display the low temperature fuel temperature. The second pressure regulating unit is used to pressurize the second filtered fuel after it is boosted by the low-temperature fuel pump. Based on the fuel pressure index required by the aircraft engine, the regulating valve and the pressure transmitter are used to return the excess second filtered fuel through the overflow valve to obtain the second regulated fuel, which is then transmitted to the aircraft engine test bench. The second reflux processing unit is used to return the excess second filtered fuel to the aviation kerosene storage tank through the return oil main pipe, and determine the mass flow of the reflux fuel through the calibrated mass flow meter installed at the return oil main pipe.

8. The low-temperature fuel system for an aircraft engine test bench according to claim 7, characterized in that: The temperature regulating unit comprises: Refrigeration-refrigerant heat exchange block: The chiller starts the compressors of the corresponding temperatures according to the input preset low temperature, and exchanges heat between the refrigerant and the refrigerant in the evaporator through evaporation compression and isobaric expansion; Adjustment block: adjusts the temperature of the coolant through the electric heater, and displays the coolant temperature through the corresponding temperature sensor after adjustment; Carrier refrigerant-fuel heat exchange block: The carrier refrigerant and fuel are exchanged in the heat exchanger. After the carrier refrigerant exchanges heat with the fuel, it takes away the heat of the fuel. The temperature after heat exchange is displayed by the temperature sensor, and then it enters the evaporator again to exchange heat with the carrier refrigerant. The cycle is repeated in sequence to continuously produce low-temperature fuel.

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