Integrated high-precision fuel flow test method and detection method

Abstract

The invention relates to the technical field of fuel nozzle performance testing, in particular to an integrated high-precision fuel flow testing method and detection method.The testing method comprises the steps that a spraying test bed or a nozzle test bed is correspondingly selected based on whether a to-be-tested workpiece tests the spraying angle or not; after the integrated high-precision fuel oil flow testing device is in a reset state, a corresponding motor rotating speed is input to a digital control system based on the calibrated flow of the workpiece to be tested, a plunger pump of a high-pressure oil supply system is started, and oil liquid in an oil tank system is pumped to a corresponding spray test bed or nozzle test bed to run; the actual pressure difference of the workpiece to be measured is collected and transmitted to the digital control system, the actual pressure difference and the target pressure difference are compared, and the actual pressure difference is adjusted; when the preliminarily obtained actual oil flow is larger than a detection threshold value, the actual oil flow corresponding to the current flowmeter is defined as corresponding detection data; and when the preliminarily obtained actual oil flow is smaller than or equal to the detection threshold value, a weighing method is adopted for flow detection.

Description

Technical Field

[0001] This invention relates to the field of fuel nozzle performance testing technology, specifically to an integrated high-precision fuel flow testing method and detection method. Background Technology

[0002] Driven by the demand for high precision, the aero-engine parts testing equipment industry is developing its technology towards multi-parameter and extreme working condition simulation. However, due to the reliance on imported core components, the high maturity of the technology, the established stable technology system, long verification cycle, stable market demand, and limited innovation motivation of enterprises, problems such as high product prices, long domestic after-sales response cycle, and low level of automation still need to be overcome.

[0003] In aero-engine components, fuel nozzles are a key core component of the combustion chamber. The spray angle, atomization uniformity, and other fuel mist characteristics of the fuel nozzle, along with related fuel flow parameters, are core indicators for evaluating fuel nozzles. They play a crucial role in combustion chamber fault diagnosis and performance improvement, such as identifying faults caused by abnormal fuel mist or flow deviations leading to incomplete combustion and carbon buildup. However, existing testing methods for fuel nozzles and fuel flow parameters have significant shortcomings. First, existing testing equipment often uses single devices, requiring specific equipment for each measurement requirement to obtain relevant data. This results in high testing costs, cumbersome processes, and low efficiency, hindering the coordinated control of test parameters and data linkage analysis, thus affecting operational consistency. Second, it is difficult to quickly and accurately adjust differential pressure to match testing requirements, limiting the flexibility in matching corresponding testing strategies and resulting in low levels of automation. Summary of the Invention

[0004] To address the problems of cumbersome, inefficient, and slow-matching detection strategies in existing fuel flow testing methods, as well as low levels of automation, this invention aims to provide an integrated high-precision fuel flow testing method. This method is implemented using an integrated high-precision fuel flow testing device, which includes a spray test bench, a nozzle test bench, a fuel tank system, a high-pressure fuel supply system, and a digital control system. The digital control system includes a servo valve for adjusting the pressure differential. The integrated high-precision fuel flow testing method includes: Acquire the workpiece to be tested, and select either the spray test bench or the nozzle test bench based on whether the spray angle of the workpiece to be tested is to be tested. After the integrated high-precision fuel flow test device is in the reset state, the corresponding motor speed is input to the digital control system based on the calibrated flow of the workpiece to be tested, and the plunger pump of the high-pressure fuel supply system is started to draw the oil in the fuel tank system to the corresponding spray test bench or nozzle test bench for operation. Based on the calibrated flow rate of the workpiece under test, the corresponding target pressure difference is input to the digital control system. The actual pressure difference of the workpiece under test is collected and transmitted to the digital control system. The actual pressure difference is compared with the target pressure difference, and the actual pressure difference is adjusted. A detection threshold is set for the oil flow rate. The flow meter is used to detect the oil flow rate based on the adjusted actual pressure difference to obtain the preliminary actual oil flow rate, which is then compared with the detection threshold. When the preliminary actual oil flow rate is greater than the detection threshold, the actual oil flow rate corresponding to the current flow meter is defined as the corresponding detection data. When the preliminary actual oil flow rate is less than or equal to the detection threshold, the flow rate is detected by weighing.

[0005] Preferably, the spray test bench or nozzle test bench is selected based on whether the spray angle of the workpiece to be tested is being measured, specifically: When testing the spray angle of the workpiece, select the spray test bench; when not testing the spray angle of the workpiece, select the nozzle test bench.

[0006] Preferably, the oil in the oil tank system is drawn into the corresponding spray test bench or nozzle test bench for operation, including: Multiple filters and particle counters are sequentially installed between the fuel tank system and the spray test bench or nozzle test bench, close to the fuel tank system. The oil pumped by the plunger pump is filtered through multiple filters and then transferred to the corresponding spray test bench or nozzle test bench for operation. The cleanliness of the filtered oil is determined by using a particle counter, and the cleanliness information is then uploaded to the digital control system.

[0007] Preferably, the actual pressure difference is compared with the target pressure difference, and the actual pressure difference is adjusted accordingly, specifically as follows: When the actual pressure difference is less than the target pressure difference, the digital control system sends an adjustment signal to the servo valve to increase the opening of the servo valve and control the increase of the flow of oil back to the oil tank system for pressurization. When the actual pressure difference is greater than or equal to the target pressure difference, the digital control system sends an adjustment signal to the servo valve to reduce the opening of the servo valve and control the oil to reduce the flow rate back to the oil tank system to reduce pressure.

[0008] Preferably, a corresponding valve stem position is set based on increasing or decreasing the servo valve opening, and an analog position sensor is set near the servo valve to detect whether the valve stem position of the servo valve has reached the valve stem position when the servo valve opening is adjusted.

[0009] Preferably, the flow rate is detected using a weighing method, including: When a nozzle test stand is selected, the nozzle test stand includes a turntable, a rotary cylinder arranged sequentially near the turntable, and multiple first oil lines. At the end of the turntable opposite to the rotary cylinder, a dividing plate and multiple second oil lines corresponding to the first oil lines are arranged sequentially. The first and second oil lines are arranged at uniform intervals around the turntable. A first main oil line and a second main oil line are respectively arranged between the first and second oil lines. Multiple sub-weighing barrels are connected to the second oil lines, and any sub-weighing barrel is defined as the main weighing barrel. A weighing sensor is arranged at the end of each sub-weighing barrel opposite to the second oil line. When testing the uniformity of the workpiece, the turntable is aligned with the dividing plate by the rotary cylinder. Based on the dividing plate, the oil flows into the sub-weighing barrel through the first and second oil lines. A preset timing period is established, and the digital control system times the accumulation of oil in the sub-weighing barrel until the timing period is reached. The corresponding data from the weighing sensor is collected, and the current fuel flow rate and uniformity are obtained by combining the timing period. When the uniformity of the workpiece to be tested is not being tested, the current fuel flow rate is obtained based on the corresponding data from the weighing sensor in the total weighing barrel. When a spray test bench is selected, the spray test bench includes a probe and a displacement sensor. The probe is moved until it comes into contact with the oil spray, and the displacement data of the displacement sensor is collected to obtain the oil spray cone angle.

[0010] Preferably, a shuttle valve is installed on the main weighing barrel and the sub-weighing barrel near the weighing sensor. After the flow detection is completed, the shuttle valve is opened, and the oil in the main weighing barrel or the sub-weighing barrel flows back to the oil tank system.

[0011] To address the above problems, the present invention also provides: an integrated high-precision fuel flow detection method for detecting whether the nozzle closure of a high-pressure fuel supply system is qualified, the method comprising: Configure the human-computer interaction unit, set the detection parameters, and initialize it; A flow meter is placed near the nozzle to collect the nozzle outlet flow rate, which is then compared with the detection parameters to determine whether the flow is continuous. If not, use an industrial camera to capture images of the nozzle outlet and preprocess them to identify oil droplets, determine the number of oil droplets, compare them with the detection parameters, and determine whether the nozzle closure is qualified. If not, notify the maintenance personnel.

[0012] Preferably, the detection parameters include detection duration, maximum allowable number of drops, and flow rate threshold.

[0013] Preferably, an industrial camera is used to acquire images of the nozzle outlet and preprocess them to identify oil droplets and determine the number of oil droplets, including: Preprocess the nozzle outlet image using either grayscale or binarization. Morphological analysis was performed on the preprocessed nozzle exit image to filter oil droplets by area and roundness. Track the movement trajectory of oil droplets based on the optical flow method, determine oil leakage according to the chronological order of the detection duration, and count the number of oil droplets during the oil leakage within the detection duration.

[0014] The present invention has the following beneficial effects: 1. Implement an integrated high-precision fuel flow test method through an integrated high-precision fuel flow test device. That is, relying on the integrated device, integrate the spray test bench and the nozzle test bench into one, and flexibly switch according to whether the workpiece to be tested needs to test the spray angle. There is no need to configure multiple independent devices for different detection requirements, reducing the test cost, avoiding the cumbersome process of switching the workpiece between multiple independent devices, achieving linkage analysis, and improving the test efficiency; cooperate with the servo valve to start the automatic adjustment mode according to the pressure difference signal, solve the limitations of low pressure difference adjustment accuracy and slow response in traditional tests, ensure that the pressure difference always matches the test requirements, and reduce the manual intervention error, enhancing the automation level of the test process; then determine the measurement scheme of the final flowmeter or weighing method according to the initially collected actual oil flow rate, which not only ensures the detection efficiency in the conventional flow scenario but also avoids the possible accuracy deviation problem of the flowmeter under large flow rates, ensuring the accuracy of test data within the full flow range and preventing the situation of combustion chamber failure caused by inaccurate test data; that is, through an integrated, high-precision, and automated fuel flow test method, achieve the efficient collaborative detection of the spray angle and fuel flow parameters of the fuel nozzle, improve the detection accuracy and efficiency, reduce the detection cost, and meet the urgent needs of the domestic aero-engine manufacturing industry for the detection of high-quality fuel nozzles.

[0015] 2. The present invention also provides an integrated high-precision fuel flow detection method for detecting whether the nozzle closed state is qualified, achieving accurate determination of the "no continuous outflow + tiny leakage" working condition, improving the accuracy of fuel system seal performance detection, and effectively avoiding fuel waste and environmental pollution caused by tiny leakage, and is applicable to fields with extremely high requirements for the reliability of fuel systems such as aero-engines and automotive engines. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a step flowchart of an integrated high-precision fuel flow test method provided by an embodiment of the present invention; Figure 2This is a schematic block diagram of an integrated high-precision fuel flow testing method provided in one embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of the nozzle test bench for an integrated high-precision fuel flow testing method provided in one embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of a weighing barrel in an integrated high-precision fuel flow testing method provided in one embodiment of the present invention. Figure 5 This is a partial structural schematic diagram of a spray test bench for an integrated high-precision fuel flow testing method provided in one embodiment of the present invention. Figure 6 A flowchart illustrating the steps of an integrated high-precision fuel flow detection method according to an embodiment of the present invention; In the picture: 1. Nozzle test bench; 2. Spray test bench; 10. Turntable; 11. Rotary cylinder; 12. First oil line; 13. Dividing plate; 14. Second oil line; 15. First main oil line; 16. Second main oil line; 17. Sub-weighing bucket; 18. Weighing sensor; 19. Shuttle valve; 20. Probe; 21. Displacement sensor. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of an integrated high-precision fuel flow testing method and detection method proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] The following description, in conjunction with the accompanying drawings, details the specific scheme of the integrated high-precision fuel flow testing method and detection method provided by the present invention.

[0021] Please combine Figure 1 and Figure 2This document illustrates a flowchart and structural block diagram of an integrated high-precision fuel flow testing method provided in the first embodiment of the present invention. The method is implemented by an integrated high-precision fuel flow testing device, which includes a spray test bench 2, a nozzle test bench 1, a fuel tank system, a high-pressure fuel supply system, and a digital control system. The digital control system includes a servo valve for adjusting the pressure difference. The integrated high-precision fuel flow testing method includes: Step SA1: Obtain the workpiece to be tested, and select either spray test bench 2 or nozzle test bench 1 based on whether the spray angle of the workpiece to be tested is to be tested; Step SA2: After the integrated high-precision fuel flow test device is in the reset state, the corresponding motor speed is input to the digital control system based on the calibrated flow of the workpiece to be tested, and the plunger pump of the high-pressure fuel supply system is started to draw the oil in the fuel tank system to the corresponding spray test bench 2 or nozzle test bench 1 for operation. Step SA3: Based on the calibrated flow rate of the workpiece under test, input the corresponding target pressure difference to the digital control system, collect the actual pressure difference of the workpiece under test and transmit it to the digital control system, compare the actual pressure difference with the target pressure difference, and adjust the actual pressure difference. Step SA4: Set a detection threshold for the oil flow rate. Use a flow meter to detect the oil flow rate based on the adjusted actual pressure difference to obtain the preliminary actual oil flow rate. Compare this with the detection threshold. When the preliminary actual oil flow rate is less than or equal to the detection threshold, define the actual oil flow rate corresponding to the current flow meter as the corresponding detection data. When the preliminary actual oil flow rate is greater than the detection threshold, use the weighing method to detect the flow rate.

[0022] To better illustrate, fuel flow testing is primarily used to evaluate fuel performance, thereby ensuring engine performance, fuel economy, and emission compliance. Currently, the Bauer 1538 main fuel control test bench is mainly used, which has a single function, primarily for testing and adjusting the basic parameters of the main fuel control system. To address the complex performance evaluation of fuel injectors, the Bauer 1579 fuel injector test bench needs to be purchased separately to meet more detailed testing requirements such as fuel injector atomization effect, injection angle, sealing performance, and dynamic response characteristics. This increases testing costs, expands the footprint, and complicates the operation process. Furthermore, the flow meter used for testing within the 5-200 kg / h range has an accuracy of ±0.1%~±0.3% MV, which limits the testing range and cannot measure smaller or larger flow rates, potentially leading to false positives or false negatives. This, to some extent, restricts the applicability and accuracy verification of this equipment under a wider range of operating conditions. Therefore, this application proposes an integrated high-precision fuel flow testing method.

[0023] Preferably, in this embodiment, the method is implemented using an integrated high-precision fuel flow testing device, which is equivalent to integrating the functions of two devices: the Bauer 1538 main fuel control test bench and the Bauer 1579 fuel nozzle test bench. This ensures the stability and reliability of the test results, effectively reduces the cumbersome fuel testing of traditional split test benches, increases the functional diversity of the equipment, and saves procurement costs and equipment space. Furthermore, it incorporates more refined zoning in conjunction with flow testing, improving measurement accuracy and making test conditions more flexible, ensuring that corresponding fuel flow data can be obtained within various test ranges.

[0024] As an alternative implementation method, the high-pressure oil supply system and the digital control system exist independently, which can work together in the overall testing method while maintaining functional separation.

[0025] Furthermore, in step SA1, the specific steps are as follows: When testing the spray angle of the workpiece, select spray test bench 2; when not testing the spray angle of the workpiece, select nozzle test bench 1.

[0026] It is explained that the workpiece to be tested refers to the fuel to be tested. In this embodiment, the fuel testing for aero engines is mainly described to prevent performance changes due to incomplete combustion, additive decomposition, or contaminant intrusion during use. In practical applications, the appropriate test bench is connected according to whether the fuel spray angle needs to be tested to ensure testing efficiency.

[0027] Further, in step SA2, the oil in the oil tank system is drawn to the corresponding spray test bench 2 or nozzle test bench 1 for operation, including: Step SA21: Multiple filters and particle counters are sequentially installed between the oil tank system and the spray test bench 2 or nozzle test bench 1, close to the oil tank system; Step SA22: The oil pumped by the plunger pump is filtered through multiple filters and then transferred to the corresponding spray test bench 2 or nozzle test bench 1 for operation. Step SA23: Use a particle counter to detect the cleanliness of the filtered oil and upload the cleanliness information to the digital control system.

[0028] Preferably, the filter element precision of multiple filters gradually increases from the test bench towards the particle counter to perform graded filtration of the oil, ultimately ensuring that it meets the high cleanliness standard required for the task and guaranteeing the accuracy of the subsequent particle counter. Next, the particle counter is used to detect the cleanliness of the filtered oil, that is, to identify and count the number of solid particles in different size ranges in the oil, generate corresponding cleanliness data, and upload the cleanliness data to the digital control system through a transmitter for storage, analysis, trend prediction or early warning triggering, thereby ensuring the efficient and stable operation of the whole system in a clean oil environment.

[0029] Specifically, install the fixture suitable for the workpiece to be tested at the corresponding spray test bench 2 or nozzle test bench 1 fixture. Ensure that it is in the reset state, input the corresponding motor speed according to the process document corresponding to the workpiece to be tested, that is, adjust the motor speed to be suitable according to the test flow parameters of the workpiece to be tested. For example, when the flow rate is 50 liters or 100 liters per minute, the speed range is set between 1000 rpm and 3000 rpm. Ensure that the set value is consistent with the actual operating speed to ensure the accuracy of the test flow. Start the plunger pump of the high-pressure oil supply system to input the oil in the oil tank system into the pipeline and operate the corresponding test bench.

[0030] Further, in step SA3, the actual pressure difference is compared with the target pressure difference, and the actual pressure difference is adjusted, specifically as follows: When the actual pressure difference is less than the target pressure difference, the digital control system sends an adjustment signal to the servo valve to increase the opening of the servo valve and control the increase of the flow of oil back to the oil tank system for pressurization. When the actual pressure difference is greater than or equal to the target pressure difference, the digital control system sends an adjustment signal to the servo valve to reduce the opening of the servo valve and control the oil to reduce the flow rate back to the oil tank system to reduce pressure.

[0031] The explanation is as follows: Based on the parameters determined in the process document of the workpiece to be tested, the target pressure difference of the current workpiece to be tested is obtained. Through the feedback of the servo valve, the opening and closing degree of the servo valve is adjusted to control the amount of oil returning to the oil tank, so as to control the actual pressure difference of the workpiece to be tested to meet the working condition requirements of the workpiece.

[0032] It can be explained that, based on the control loop formed between the servo valve, the high-pressure oil supply system, and the test bench, the entire device has the ability to automatically control the flow test at different pressure points. Its operating conditions meet the pressure requirements of the tested parts, which can effectively improve the accuracy and stability of the device and meet the testing requirements of the workpiece. Furthermore, on the basis of the flow regulation function, pressure closed-loop control is added, that is, pressure control is switched according to the comparison between the actual pressure difference and the target pressure difference.

[0033] Furthermore, based on increasing or decreasing the servo valve opening, a corresponding valve stem position is set, and an analog position sensor is placed near the servo valve to detect whether the valve stem position of the servo valve has reached the valve stem position when the servo valve opening is adjusted.

[0034] Optionally, the servo valve also integrates an electronic amplifier and a shaft controller, which work in conjunction with an analog position sensor to achieve closed-loop position control. The analog position sensor converts the mechanical displacement of the servo valve stem into a continuous analog electrical signal with stable output and good linearity. The electronic amplifier amplifies the signal output from the analog position sensor with high gain and low noise, and filters it to eliminate interference. The shaft controller compares the amplified analog position sensor signal with a preset stem position, and then precisely adjusts the stem position to ensure that its actual position always matches the preset stem position, thus ensuring that the servo valve opening degree is adjusted correctly.

[0035] Specifically, the actual pressure difference of the workpiece under test is collected by a pressure sensor and explained in conjunction with the atmospheric pressure difference. When the actual pressure difference and the atmospheric pressure difference are less than the target pressure difference, the digital control system receives the signal and sends an adjustment signal to the servo valve. The solenoid of the servo valve controls the valve core to extend forward, increasing its opening and increasing the amount of oil in the control return tank, thus achieving pressure boosting. When the actual pressure difference and the atmospheric pressure difference are greater than or equal to the target pressure difference, an adjustment signal is sent to the servo valve. The solenoid of the servo valve controls the valve core to retract backward, decreasing its opening and reducing the amount of oil in the control return tank, thus achieving pressure reduction. After either the pressure boosting or pressure reduction process is completed, the valve stem position is adjusted according to the valve stem position signal detected by the analog position sensor until the valve stem is in place.

[0036] Preferably, in this embodiment, the detection threshold in step SA4 is set to 20 kg / h, which can be adjusted according to the actual situation; thus, the low flow rate situation is further subdivided, so as to provide a reasonable solution to the problem of low accuracy of flow measurement results of ordinary flow meters under low flow rate conditions.

[0037] It can be explained that a flow meter refers to a metering instrument that can accurately measure the volume or mass of fuel passing through a pipe or device per unit time. In this embodiment, it is used to measure the fuel flow rate.

[0038] Specifically, the flow meter is first used to detect the oil flow rate based on the adjusted actual pressure difference to obtain the preliminary actual oil flow rate. When the preliminary actual oil flow rate is greater than the detection threshold, i.e., 20 kg / h, the test data corresponding to the current flow meter is directly used as the actual detection data of the oil flow rate. Conversely, when the preliminary actual oil flow rate is less than or equal to 20 kg / h, the fuel flow rate is measured by weighing.

[0039] Please combine Figure 3 and Figure 4 Furthermore, in step SA4, flow rate detection is performed using a weighing method, including: Step SA41: When nozzle test stand 1 is selected, nozzle test stand 1 includes a turntable 10 and a rotary cylinder 11 arranged sequentially near the turntable 10, and multiple first oil lines 12. At one end of the turntable 10 opposite to the rotary cylinder 11, a dividing plate 13 and multiple second oil lines 14 corresponding to the first oil lines 12 are arranged sequentially. The first oil lines 12 and the second oil lines 14 are arranged evenly spaced around each other. A first main oil line 15 and a second main oil line 16 are respectively arranged between the first oil lines 12 and the second oil lines 14. Multiple sub-pipes are connected to the second oil lines 14. The weighing tank 17 defines any sub-weighing tank 17 as the total weighing tank. A weighing sensor 18 is installed at the end of the sub-weighing tank 17 opposite to the second oil line 14. When the uniformity of the workpiece to be tested is tested, the turntable 10 is aligned with the dividing plate 13 by the rotating cylinder 11. Based on the dividing plate 13, the oil flows into the sub-weighing tank 17 through the first oil line 12 and the second oil line 14. The digital control system times the accumulation of oil in the sub-weighing tank 17 until the time is reached. The corresponding data of the weighing sensor 18 is collected, and the current fuel flow and uniformity are obtained by combining the time. When the uniformity of the workpiece to be tested is not being tested, the current fuel flow rate is obtained based on the data corresponding to the weighing sensor 18 of the total weighing barrel.

[0040] As explained, the weighing sensor 18 refers to a device that converts the weight of the oil in the weighing tank into a measurable electrical signal output to achieve accurate measurement.

[0041] Furthermore, in step SA41, a shuttle valve 19 is installed on the main weighing tank and the sub-weighing tank 17 near the weighing sensor 18. After the flow detection is completed, the shuttle valve 19 is opened, and the oil in the main weighing tank or the sub-weighing tank 17 flows back to the oil tank system.

[0042] Specifically, when uniformity needs to be tested, the turntable 10 is rotated by the rotary cylinder 11 so that the outlet of the indexing plate is directly facing the sub-weighing tank 17. After the oil is sprayed out from the workpiece to be tested, it flows into the corresponding sub-weighing tank 17 through the indexing plate. The shuttle valve 19 below the sub-weighing tank 17 is closed, and the oil accumulates in the sub-weighing tank 17. At the same time, timing is started, and the oil supply of the oil tank system is turned off. The current oil flow rate and uniformity are automatically calculated based on the value of the weighing sensor 18 below the sub-weighing tank 17 and the timing duration, i.e., the weighing time.

[0043] When uniformity testing is not required, the rotary cylinder 11 is driven back to its original position, and the flow rate is calculated directly through the weighing of the total weighing barrel. After the test, the shuttle valve 19 below the total weighing barrel opens, and the oil flows back into the oil tank. That is, during the test, the shuttle valve 19 is closed, and oil is sprayed for a certain period of time according to the requirements of the workpiece to be tested. At the same time, the transmitter sends the signal detected by the weighing sensor 18 to the digital control system. The digital control system calculates the oil mass, flow rate, and uniformity of each weighing barrel. That is, the oil flow rate and uniformity are determined by the digital control system.

[0044] To better illustrate this, the following explanation is based on the test results observed in this embodiment: When the initial actual flow rate of the oil is >20kg / h, the flow rate is tested using a flow meter, and uniformity testing is not required. The oil flows from the first main oil line 15 to the second main oil line 16, and finally flows back to the oil tank system.

[0045] When the initial actual flow rate of the oil is >20kg / h, the flow rate of the oil is tested using a flow meter, and the uniformity needs to be tested. The oil flows from the first oil line 12 into the second main oil line 16, and finally flows back to the oil tank system.

[0046] When the initial actual flow rate of the oil is <20kg / h, the flow rate of the oil is tested using a flow meter, and the uniformity test is not required. The oil flows from the first main oil pipeline 15 to the total weighing tank, and the oil flow rate and spray uniformity are calculated by the total weighing tank in combination with the timing duration.

[0047] When the initial actual flow rate of the oil is <20kg / h, the flow rate of the oil is tested using a flow meter, and the uniformity needs to be tested. The oil flows from the first oil pipeline 12 into the second oil pipeline 14, and the oil flow rate and spray uniformity are calculated by the sub-weighing tank 17 in combination with the timing duration.

[0048] Please see Figure 5 Step SA42: When the spray test stand 2 is selected, the spray test stand 2 includes a probe 20 and a displacement sensor 21. Move the probe 20 until it contacts the oil spray, and collect the displacement data of the displacement sensor 21 to obtain the oil spray cone angle.

[0049] Specifically, after the oil mist is stably sprayed out, the probe 20 is moved towards the center in the X direction. The probe 20 is observed to just touch the oil mist, that is, the metal contact at the front end of the probe 20 forms a weak electrostatic adsorption with the edge of the oil mist, so that the probe 20 feels the change in resistance during the movement. Then, the X-direction displacement sensor 21 transmits the displacement data to the digital control system to calculate the spray cone angle. After the spray cone angle is tested, the operation of the rotary cylinder 11 is determined according to whether the uniformity of the workpiece to be tested is tested, which is the same as the nozzle test bench 1.

[0050] Preferably, in this embodiment, the flow measurement range can reach 0.5 kg / h to 500 kg / h, and the flow measurement accuracy is 0.10%; wherein, the large pressure measurement range is 0-10 MPa with an accuracy of 4 kPa; the medium pressure measurement range is 0-1.5 MPa with an accuracy of 0.6 kPa; and the small pressure measurement range is 0-160 kPa with an accuracy of 0.064 kPa.

[0051] Understandably, the integrated high-precision fuel flow testing device enables an integrated high-precision fuel flow testing method. This involves integrating the spray test bench 2 and the nozzle test bench 1 into a single unit. Flexible switching is possible based on whether the workpiece requires spray angle testing, eliminating the need for multiple independent devices for different testing needs. This reduces testing costs and avoids the cumbersome process of switching workpieces between multiple independent devices. It also enables linked analysis, improving testing efficiency. Furthermore, the servo valve activates an automatic adjustment mode based on the differential pressure signal, overcoming the limitations of low differential pressure adjustment accuracy and slow response in traditional testing. This ensures that the differential pressure always matches the testing requirements and reduces manual intervention. The reduced error improves the automation level of the testing process. Based on the initial collected actual oil flow rate, the final measurement scheme using either a flow meter or a weighing method is determined. This ensures testing efficiency under normal flow rate conditions while avoiding potential accuracy deviations in flow meters under high flow rates, guaranteeing the accuracy of test data across the entire flow range and preventing combustion chamber malfunctions due to inaccurate test data. In short, through an integrated, high-precision, and automated fuel flow testing method, efficient collaborative detection of fuel nozzle spray angle and fuel flow parameters is achieved, improving testing accuracy and efficiency, reducing testing costs, and meeting the urgent needs of the domestic aero-engine manufacturing industry for high-quality fuel nozzle testing.

[0052] Please combine Figure 1 and Figure 6 The second embodiment of the present invention provides an integrated high-precision fuel flow detection method for detecting whether the nozzle closure of a high-pressure fuel supply system is qualified. The method includes: Step SB1: Configure the human-computer interaction unit, set the detection parameters and initialize it; Step SB2: Place a flow meter near the nozzle to collect the nozzle outlet flow rate, compare it with the detection parameters, and determine whether the flow is continuous; Step SB3: If not, use an industrial camera to acquire images of the nozzle outlet and preprocess them to identify oil droplets, determine the number of oil droplets, compare them with the detection parameters, and determine whether the nozzle closure is qualified. If not, notify the maintenance personnel.

[0053] To better illustrate this, existing technologies for nozzle detection typically use sensors, but these sensors cannot capture subtle changes, resulting in insufficient detection accuracy and reliability, a tendency to make misjudgments, an inability to respond in a timely manner, low detection efficiency, and a tendency to produce biased results.

[0054] It can be noted that in this embodiment, the flow meter refers to a micro-flow monitoring unit, which is installed in the fuel nozzle outlet pipeline and adopts a high-sensitivity micro-flow meter such as a Coriolis or thermal micro-flow meter. The Coriolis flow meter directly measures the mass flow rate by detecting the Coriolis force generated by the oil in the vibrating tube, and has the characteristic of being unaffected by parameters such as fluid density and viscosity. The thermal micro-flow meter uses the heat exchange relationship between the heating element and the temperature sensor to calculate the flow rate by measuring the corresponding amount of heat carried away by the oil.

[0055] Furthermore, the detection parameters include detection duration, maximum allowable number of drops, and flow rate threshold.

[0056] The human-computer interaction unit is used to set detection parameters, display real-time flow rate and drop count, and determine the final judgment result; the detection duration is... minutes; maximum allowed drop count is Drop; flow threshold is The flow rate is measured in milliliters per minute. Preferably, in this embodiment, the flow rate threshold is set to 0.1 mL / min.

[0057] Further, in step SB3, an industrial camera is used to acquire images of the nozzle outlet and preprocess them to identify oil droplets and determine the number of oil droplets, including: Step SB31: Preprocess the nozzle outlet image by either grayscale conversion or binarization.

[0058] Specifically, the nozzle exit image is converted into a grayscale image, which is simplified to single brightness information. Then, the Otsu (Otsu's Thresholding) adaptive thresholding segmentation algorithm is used to binarize the grayscale image, remove background noise, effectively distinguish the foreground oil droplet area from the background noise area, and clearly extract the outline and morphological features of the oil droplets.

[0059] Step SB32: Perform morphological analysis on the preprocessed nozzle outlet image and filter oil droplets by area and roundness.

[0060] Specifically, based on the task requirements, pre-set appropriate oil droplet area and roundness thresholds for screening, perform morphological analysis on the pre-processed nozzle outlet image, and determine the effective oil droplets when the detected area or roundness exceeds the corresponding threshold. This is used for screening to exclude splashed oil droplets and effectively improve the accuracy of oil droplet identification.

[0061] Step SB33: Track the trajectory of oil droplets based on optical flow method, determine the oil leakage according to the time sequence of detection time, and count the number of oil droplets within the detection time.

[0062] Specifically, optical flow is used to track the trajectory of oil droplets. This involves estimating the motion vector by analyzing the grayscale changes and spatial displacement of pixels in consecutive image frames. Pixel-by-pixel motion analysis is performed on adjacent frames, and the horizontal and vertical velocity components of each pixel are obtained by solving the least-squares equation of the grayscale gradient matrix. The optical flow vector is then correlated with the actual motion of the oil droplets to determine their time-varying trajectory. Next, "independent dripping events" are determined based on the order of detection time. An independent dripping event is defined as a time interval between two adjacent oil droplets exceeding a preset calibration value. The total number of droplets within the detection time is then counted and recorded as follows: .

[0063] It can be explained that an integrated high-precision fuel flow detection method is based on a closed-loop detection logic of multi-source data fusion, and its specific operating principle is as follows: First, the detection parameters are input through the human-computer interaction unit; then, a micro-flow meter is used to collect the nozzle outlet flow rate, which is recorded as follows. The flow is filtered using methods such as moving average, and compared with a flow threshold to determine if there is continuous outflow. If the condition is met... If marked as "continuous outflow exists," it indicates the nozzle is not properly closed, and maintenance personnel are notified; if the condition is met... The next step involves determining if there is oil leakage. An industrial camera is then used to continuously capture and identify images of the nozzle outlet. If, without continuous outflow, the total number of oil droplets within the detection period exceeds the maximum permissible number, then... When the nozzle shows a slight leak, it indicates that the nozzle is not properly closed, and maintenance personnel are notified to manually verify and close it. Conversely, when there is no continuous flow and When the nozzle is closed properly, it indicates that the nozzle is properly closed.

[0064] Understandably, by using an integrated high-precision fuel flow detection method to accurately determine the "no continuous outflow + minute drip" condition, the accuracy of fuel system sealing performance testing can be improved. It can also effectively avoid fuel waste and environmental pollution caused by minute drips, and is suitable for fields such as aero engines and automotive engines where fuel system reliability requirements are extremely high.

[0065] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0066] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. An integrated high-precision fuel flow testing method, characterized in that, The method is implemented by an integrated high-precision fuel flow testing device, which includes a spray test bench, a nozzle test bench, a fuel tank system, a high-pressure fuel supply system, and a digital control system. The digital control system includes a servo valve for adjusting the pressure difference. The integrated high-precision fuel flow testing method includes: Acquire the workpiece to be tested, and select either the spray test bench or the nozzle test bench based on whether the spray angle of the workpiece to be tested is to be tested. After the integrated high-precision fuel flow test device is in the reset state, the corresponding motor speed is input to the digital control system based on the calibrated flow of the workpiece to be tested, and the plunger pump of the high-pressure fuel supply system is started to draw the oil in the fuel tank system to the corresponding spray test bench or nozzle test bench for operation. Based on the calibrated flow rate of the workpiece under test, the corresponding target pressure difference is input to the digital control system. The actual pressure difference of the workpiece under test is collected and transmitted to the digital control system. The actual pressure difference is compared with the target pressure difference, and the actual pressure difference is adjusted. A detection threshold is set for the oil flow rate. The flow meter is used to detect the oil flow rate based on the adjusted actual pressure difference to obtain the preliminary actual oil flow rate, which is then compared with the detection threshold. When the preliminary actual oil flow rate is greater than the detection threshold, the actual oil flow rate corresponding to the current flow meter is defined as the corresponding detection data. When the preliminary actual oil flow rate is less than or equal to the detection threshold, the flow rate is detected by weighing.

2. The integrated high-precision fuel flow testing method according to claim 1, characterized in that, Depending on whether the workpiece to be tested requires spray angle testing, either a spray test bench or a nozzle test bench should be selected. Specifically: When testing the spray angle of the workpiece, select the spray test bench; when not testing the spray angle of the workpiece, select the nozzle test bench.

3. The integrated high-precision fuel flow testing method according to claim 1, characterized in that, The oil in the tank system is drawn into the corresponding spray test bench or nozzle test bench for operation, including: Multiple filters and particle counters are sequentially installed between the fuel tank system and the spray test bench or nozzle test bench, close to the fuel tank system. The oil pumped by the plunger pump is filtered through multiple filters and then transferred to the corresponding spray test bench or nozzle test bench for operation. The cleanliness of the filtered oil is determined by using a particle counter, and the cleanliness information is then uploaded to the digital control system.

4. The integrated high-precision fuel flow testing method according to claim 1, characterized in that, Compare the actual pressure difference with the target pressure difference, and adjust the actual pressure difference accordingly, specifically as follows: When the actual pressure difference is less than the target pressure difference, the digital control system sends an adjustment signal to the servo valve to increase the opening of the servo valve and control the increase of the flow of oil back to the oil tank system for pressurization. When the actual pressure difference is greater than or equal to the target pressure difference, the digital control system sends an adjustment signal to the servo valve to reduce the opening of the servo valve and control the oil to reduce the flow rate back to the oil tank system to reduce pressure.

5. The integrated high-precision fuel flow testing method according to claim 4, characterized in that, Based on the setting of the corresponding valve stem position for increasing or decreasing the servo valve opening, an analog position sensor is placed near the servo valve to detect whether the valve stem position of the servo valve has reached the valve stem position when the servo valve opening is adjusted.

6. The integrated high-precision fuel flow testing method according to claim 4, characterized in that, Flow rate detection using the weighing method includes: When a nozzle test stand is selected, the nozzle test stand includes a turntable, a rotary cylinder arranged sequentially near the turntable, and multiple first oil lines. At the end of the turntable opposite to the rotary cylinder, a dividing plate and multiple second oil lines corresponding to the first oil lines are arranged sequentially. The first and second oil lines are arranged at uniform intervals around the turntable. A first main oil line and a second main oil line are respectively arranged between the first and second oil lines. Multiple sub-weighing barrels are connected to the second oil lines, and any sub-weighing barrel is defined as the main weighing barrel. A weighing sensor is arranged at the end of each sub-weighing barrel opposite to the second oil line. When testing the uniformity of the workpiece, the turntable is aligned with the dividing plate by the rotary cylinder. Based on the dividing plate, the oil flows into the sub-weighing barrel through the first and second oil lines. A preset timing period is established, and the digital control system times the accumulation of oil in the sub-weighing barrel until the timing period is reached. The corresponding data from the weighing sensor is collected, and the current fuel flow rate and uniformity are obtained by combining the timing period. When the uniformity of the workpiece to be tested is not being tested, the current fuel flow rate is obtained based on the corresponding data from the weighing sensor in the total weighing barrel. When a spray test bench is selected, the spray test bench includes a probe and a displacement sensor. The probe is moved until it comes into contact with the oil spray, and the displacement data of the displacement sensor is collected to obtain the oil spray cone angle.

7. The integrated high-precision fuel flow testing method according to claim 6, characterized in that, Shuttle valves are installed near the load cells on the main weighing tank and the sub-weighing tanks. After the flow detection is completed, the shuttle valves are opened, and the oil in the main weighing tank or the sub-weighing tank flows back to the oil tank system.

8. An integrated high-precision fuel flow detection method, characterized in that, The method for detecting whether the nozzle closure of a high-pressure oil supply system is qualified includes: Configure the human-computer interaction unit, set the detection parameters, and initialize it; A flow meter is placed near the nozzle to collect the nozzle outlet flow rate, which is then compared with the detection parameters to determine whether the flow is continuous. If not, use an industrial camera to capture images of the nozzle outlet and preprocess them to identify oil droplets, determine the number of oil droplets, compare them with the detection parameters, and determine whether the nozzle closure is qualified. If not, notify the maintenance personnel.

9. The integrated high-precision fuel flow detection method according to claim 8, characterized in that, The detection parameters include detection duration, maximum allowable number of drops, and flow rate threshold.

10. The integrated high-precision fuel flow detection method according to claim 9, characterized in that, Industrial cameras are used to acquire images of the nozzle exit and preprocess them to identify oil droplets and determine the number of droplets, including: Preprocess the nozzle outlet image using either grayscale or binarization. Morphological analysis was performed on the preprocessed nozzle exit image to filter oil droplets by area and roundness. The movement trajectory of oil droplets is tracked using optical flow method. Oil leakage is determined according to the time sequence of detection time, and the number of oil droplets within the detection time is counted.

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