A test bench for liquid flow meters for aircraft

Abstract

The application discloses a kind of liquid flowmeter test benches for aviation, including oil storage tank, the oil return pipeline of calibration, life verification loop pipeline, flow measurement precision calibration and life simultaneous verification loop are connected with respectively in the oil storage tank, the oil return pipeline of calibration, life verification loop pipeline, flow measurement precision calibration and life simultaneous verification loop are parallel between each other.The application can be according to the fuel consumption curve of fuel in the actual flight process of aircraft, flow measurement precision calibration is carried out to flowmeter;It can be set by software, according to the fuel consumption curve of fuel in the actual flight process of aircraft, long time life verification test is carried out to flowmeter;It can be according to the fuel consumption curve of fuel in the actual flight process of aircraft, flow measurement precision calibration and long time life verification test are carried out to flowmeter simultaneously.

Description

Technical Field

[0001] This invention relates to the field of aviation flow calibration technology, specifically to a test bench for aviation liquid flow meters. Background Technology

[0002] Liquid flow meter test benches can be used to simulate fuel consumption curves during aircraft flight, conducting tests to verify the accuracy and service life of flow meter measurements. Instantaneous flow rate detection and cumulative flow rate detection can provide pilots with accurate information on the remaining fuel level in the fuel tank; detect the operating status of the aircraft engine; perform fault detection in the aircraft fuel system; and provide control parameters for the aircraft fuel system. The accuracy and reliability of fuel level detection are directly related to the control accuracy and reliability of the aircraft fuel system, and thus to the overall flight safety of the aircraft.

[0003] Currently, domestic fuel flow meters can only be calibrated for flow measurement accuracy by selecting a few constant fuel flow calibration points according to the actual fuel flow range during aircraft use, or by conducting a life verification test for a period of time at a constant fuel rate, and then continuing the life verification test for a period of time by manually changing the constant fuel rate. It is impossible to calibrate the flow measurement accuracy of the flow meter according to the fuel consumption curve during actual aircraft flight; it is also impossible to conduct long-term life verification tests of the flow meter according to the fuel consumption curve during actual aircraft flight through software settings; and it is even more impossible to simultaneously perform flow measurement accuracy calibration and long-term life verification tests according to the fuel consumption curve during actual aircraft flight. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid flow meter test bench that simulates the fuel consumption curve during actual aircraft flight and can simultaneously perform flow measurement accuracy calibration and long-term life verification tests on the flow meter.

[0005] This invention is achieved through the following technical solution: a test bench for an aviation liquid flow meter, characterized in that it includes an oil storage tank, wherein the oil storage tank is respectively connected to a calibration return oil pipeline, a life verification loop pipeline, and a flow measurement accuracy calibration and life simultaneous verification loop, wherein the calibration return oil pipeline, the life verification loop pipeline, and the flow measurement accuracy calibration and life simultaneous verification loop are connected in parallel with each other;

[0006] The calibration return oil line is used for flow measurement accuracy calibration.

[0007] The life verification loop is used for long-term life verification tests.

[0008] The flow measurement accuracy calibration and life verification loop is used to simultaneously perform flow measurement accuracy calibration and long-term life verification tests.

[0009] The working principle of this technical solution is as follows: the test flow meter is installed in the test pipeline through a clamp. A variable frequency pump draws fuel from the oil storage tank to generate flow. The fluid flows through a flow stabilizing container and a degassing filter into a passive volumetric tube. The measurement and control system controls the fuel flow rate and the time it takes to pass through the test flow meter, generating a VH fuel flow curve corresponding to the flow rate and time. The fuel flows through the test flow meter, and the measurement and control system collects the output signal of the test flow meter for processing and analysis. The fuel that has flowed through the test flow meter returns to the oil storage tank through the calibration return line or the life verification loop line.

[0010] This invention allows for the calibration of a flow meter's measurement accuracy by setting a constant fuel flow rate. The measurement accuracy is measured at several selected flow points within the flow meter's linear flow range, with the measurement accuracy 'a' at each calibration point being:

[0011]

[0012] Q 实测 —The current fuel flow rate measured by the flow meter, in liters per hour (L / h).

[0013] Q 标准 —Standard flow rate provided for the test bench, in liters per hour (L / h).

[0014] a—Measurement accuracy of the current flow measurement point

[0015] Based on the fuel consumption curve during actual flight, the VH parameter corresponding to the flow rate and time can be input to the test bench via software settings. The test bench controls the passive volumetric tube and standard flow meter to output the corresponding standard flow rate according to the time coordinate, thereby simulating the fuel consumption curve during actual flight. The measurement accuracy of the flow meter is calibrated according to the aircraft's fuel consumption curve for one flight. The measurement accuracy β during flight is:

[0016]

[0017] Q 实测 —The current fuel flow rate measured by the flow meter, in liters per hour (L / h).

[0018] Q 标准 —This represents the standard flow rate at a specific time point provided by the fuel consumption curve on the test bench, expressed in liters per hour (L / h).

[0019] β—the measurement accuracy of the flow meter per flight.

[0020] A lifespan verification test of the flow meter is conducted at a constant fuel flow rate. This can be achieved by setting a constant flow rate on the test bench, collecting the current fuel flow rate measured by the flow meter, comparing it with the standard flow rate output by the test bench, and judging according to formula (3). If the flow meter's measurement accuracy requirements are met, the test continues until the flow meter's measurement accuracy exceeds the design requirement γ, at which point the test is stopped. The lifespan H of the flow meter is:

[0021]

[0022] Q 实测 —The current fuel flow rate measured by the flow meter, in liters per hour (L / h).

[0023] Q 标准 —Standard flow rate provided for the test bench, in liters per hour (L / h).

[0024] γ—Measurement accuracy specification for flowmeter design

[0025] H—Lifespan of the flow meter at constant flow rate

[0026] The life verification test of the flow meter is carried out according to the fuel consumption curve during the actual flight of the aircraft. The VH parameter corresponding to the flow rate and time can be input to the test bench through software settings. The test bench controls the passive volume tube and the standard flow meter to output the corresponding standard flow rate according to the time coordinate. After one flight, the measurement accuracy β of the flow meter under the current flight is calculated according to formula (2). If the measurement accuracy requirement γ of the flow meter is met under the current flight, the flow meter continues to carry out the test until the measurement accuracy of the flow meter exceeds the design requirements, and the test is stopped. The life of the flow meter τ is:

[0027]

[0028] β—the measurement accuracy of the flow meter per flight.

[0029] γ—Measurement accuracy specification for flowmeter design

[0030] h—Time of one flight sortie

[0031] τ—Lifespan of the flow meter based on the actual fuel consumption curve of the aircraft.

[0032] The standard flow rate is provided by a passive volumetric osmosis (VOS) tube. The current standard flow rate is measured by a standard flow meter and transmitted to the control system. The control system then adjusts the VOS tube to bring the standard flow rate closer to the target flow rate. The working principle of the passive VOS tube is as follows: When the piston is in the initial position, the lift valve is closed, and the fluid pushes the piston. The contact points on the piston rod pass through two photoelectric conversion switches, completing one working stroke. The distance between the two conversion switches and the cross-sectional area of ​​the piston are determined, therefore the volume of fluid discharged by the piston after passing through the two conversion switches is determined. Dividing this volume by the measurement time gives the standard flow rate. When the piston reaches its final position, the lift valve automatically opens, and the piston returns to its initial position via a return mechanism. Based on the VOS tube measurement principle, the formula for the standard flow rate is:

[0033]

[0034] In the formula:

[0035] S—Cross-sectional area of ​​the volume tube piston;

[0036] L—Displacement of the piston in the volume tube;

[0037] t—Measurement time.

[0038] To better realize the present invention, the calibration return oil pipeline further includes a frequency converter pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a standard flow meter assembly, a standard flow meter, and a residual oil collection tank connected in series via pipelines. The residual oil collection tank is connected to the oil storage tank via a pipeline.

[0039] To better realize the present invention, the life verification circuit pipeline further includes a variable frequency pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a three-way valve, and a residual oil collection tank connected in series via a pipeline. The residual oil collection tank is connected to the oil storage tank via a pipeline.

[0040] To better realize the present invention, the pipeline connecting the residual oil collection tank and the oil storage tank is further equipped with a pneumatic ball valve, a frequency converter pump, and a filter.

[0041] To better realize the present invention, the flow measurement accuracy calibration and life verification circuit further includes a variable frequency pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a standard flow meter assembly, and a filter connected in series via a pipeline. The filter is connected to the oil storage tank via a pipeline.

[0042] To better realize the present invention, the passive piston volume tube assembly is further provided with at least two passive piston volume tubes connected in parallel, and each passive piston volume tube is provided with an independent pneumatic ball valve at both ends of the parallel pipeline.

[0043] To better realize the present invention, the watch clamp assembly is further provided with at least two watch clamps connected in parallel.

[0044] To better realize the present invention, the standard flow meter group is further provided with at least three standard flow meters connected in parallel, and each standard flow meter is provided with an independent pneumatic ball valve on the parallel pipeline.

[0045] To better realize the present invention, it further includes a frequency converter control cabinet, wherein the frequency converter control cabinet is equipped with a measurement and control system for controlling the on and off of the pneumatic ball valve, and the measurement and control system is connected to a PC.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] (1) The present invention can calibrate the flow measurement accuracy of the flow meter according to the fuel consumption curve during the actual flight of the aircraft;

[0048] (2) The present invention can conduct long-term life verification tests on the flow meter by setting the fuel consumption curve during the actual flight of the aircraft through software settings.

[0049] (3) The present invention can simultaneously calibrate the flow measurement accuracy of the flow meter and conduct long-term life verification tests according to the fuel consumption curve of the aircraft during actual flight.

[0050] (4) The oil storage tank of the present invention includes a series and parallel connection of pipelines, which can realize the switching of different liquid media required for the test and avoid waste when changing the liquid media required for the test; at the same time, the number of oil storage tanks can be matched according to the test needs by connecting several oil storage tanks in series, thereby reducing the test site area. Attached Figure Description

[0051] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0052] Figure 1 This is a schematic diagram illustrating the operation of flow measurement accuracy calibration in this invention;

[0053] Figure 2 This is a schematic diagram of the long-term life verification test in this invention.

[0054] Figure 3 This is a schematic diagram illustrating the simultaneous operation of flow measurement accuracy calibration and long-term life verification tests in this invention. Detailed Implementation

[0055] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0056] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] Example 1:

[0059] The main structure of this embodiment is as follows: Figures 1-3 As shown, it includes an oil storage tank, which is connected to a calibration return oil pipeline, a life verification loop pipeline, and a flow measurement accuracy calibration and life verification loop. Specific components include an oil storage tank, a variable frequency pump, a flow stabilizing container, a degassing filter, a test pipeline, a passive piston volume tube, a standard flow meter, a clamp meter, a three-way valve, and a return oil pipeline.

[0060] The calibration return oil pipeline includes a pneumatic ball valve, a standard flow meter, a residual oil collection tank, and a return oil pipeline. Fuel passing through the test flow meter flows through a pipeline matching the fuel flow rate by controlling the opening and closing of the pneumatic ball valve, according to the fuel flow rate. Then, it passes through the standard flow meter on the pipeline and enters the return oil pipeline. After passing through the fuel collector, the fuel returns to the oil storage tank.

[0061] The life verification loop includes a three-way valve, a residual oil collection tank, and a return oil line. Fuel passing through the test flow meter is directed by the three-way valve to the fuel line. The fuel enters the return oil line and returns to the storage tank after passing through the fuel collector.

[0062] The flow measurement accuracy calibration and life verification loop includes a three-way valve, a starting ball valve, a standard flow meter, a residual oil collection tank, and a return oil line. Fuel passing through the test flow meter is directed to flow through the fuel line via the three-way valve. The fuel enters the calibration return oil line. By controlling the opening and closing of the pneumatic ball valve, the fuel flows through a line matching the fuel flow rate. It then passes through the standard flow meter on this line and enters the return oil line. After passing through the fuel collector, the fuel returns to the storage tank.

[0063] Select the appropriate fuel storage tank for the fuel medium required for the test, and choose the number of storage tanks according to the required fuel volume. Connect the required storage tanks to the pipeline, and then install the flow meter under test in the test pipeline using a clamp.

[0064] Fuel is drawn from the storage tank using a variable frequency pump, generating a flow rate. The fluid flows through a flow stabilizing container and a degassing filter before entering a passive volumetric flowmeter. A fuel flow rate versus time (VH) curve is set via a measurement and control system. The passive volumetric flowmeter controls the fuel flow rate and the time it takes to pass through the test flowmeter, generating a VH fuel flow rate curve corresponding to the flow rate over time. As the fuel flows through the test flowmeter, the measurement and control system simultaneously acquires and analyzes the output signal from the test flowmeter. The fuel flowing through the test flowmeter returns to the storage tank via a calibration return line or a life verification loop. If the test bench requires separate flow measurement accuracy calibration, the fuel flow through the test flowmeter is controlled by opening and closing a pneumatic ball valve, based on the fuel flow rate, to ensure the fuel flows through a path corresponding to the fuel flow rate. The fuel flows through a pipeline matched to the test flow meter, then through a standard flow meter on that pipeline, into the return fuel pipeline, and finally back to the fuel storage tank after passing through the fuel collector, thus completing the flow measurement accuracy calibration. If the test bench needs to conduct a separate life verification test, the fuel flowing through the test flow meter is controlled by a three-way valve to enter the return fuel pipeline, and then back to the fuel storage tank after passing through the fuel collector. If the test bench needs to conduct flow measurement accuracy calibration and life verification tests simultaneously, the fuel flowing through the test flow meter is controlled by a three-way valve to enter the calibration return fuel pipeline. By controlling the opening and closing of the pneumatic ball valve, the fuel flows through a pipeline matched to the fuel flow rate, then through a standard flow meter on that pipeline, into the return fuel pipeline, and finally back to the fuel storage tank after passing through the fuel collector.

[0065] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A test bench for aviation liquid flow meters, characterized in that, It includes an oil storage tank, which is connected to a calibration return oil pipeline, a life verification loop pipeline, and a flow measurement accuracy calibration and life verification loop, and the calibration return oil pipeline, the life verification loop pipeline, and the flow measurement accuracy calibration and life verification loop are connected in parallel to each other; The calibration return oil pipeline is used for flow measurement accuracy calibration; the calibration return oil pipeline includes a frequency converter pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a standard flow meter assembly, a standard flow meter, and a residual oil collection tank connected in series through a pipeline. The life verification loop pipeline is used for long-term life verification tests; the life verification loop pipeline includes a variable frequency pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a three-way valve, and a residual oil collection tank connected in series through a pipeline; the residual oil collection tank is connected to the oil storage tank through a pipeline. The flow measurement accuracy calibration and life verification loop is used to simultaneously perform flow measurement accuracy calibration and long-term life verification tests; the flow measurement accuracy calibration and life verification loop includes a variable frequency pump, a pneumatic ball valve, a flow stabilizing container, a passive piston volume tube assembly, a clamp meter assembly, a standard flow meter assembly, and a filter connected in series through a pipeline, and the filter is connected to the oil storage tank through a pipeline; It also includes a frequency converter control cabinet, which is equipped with a measurement and control system for controlling the on and off of pneumatic ball valves. The measurement and control system is connected to a PC. By inputting the VH parameter corresponding to the flow rate and time into the PC, the passive piston volume tube assembly is controlled to output a standard flow rate that matches the actual fuel consumption curve of the aircraft.

2. The test bench for an aviation liquid flow meter according to claim 1, characterized in that, The pipeline connecting the residual oil collection tank and the oil storage tank is also equipped with a pneumatic ball valve, a frequency converter pump, and a filter.

3. The test bench for an aviation liquid flow meter according to claim 1, characterized in that, The passive piston volume tube assembly is provided with at least two passive piston volume tubes connected in parallel, and each passive piston volume tube is provided with an independent pneumatic ball valve at both ends of the parallel pipeline.

4. The test bench for an aviation liquid flow meter according to claim 1, characterized in that, The watch clamp assembly is provided with at least two watch clamps connected in parallel.

5. The test bench for an aviation liquid flow meter according to claim 1, characterized in that, The standard flow meter group is equipped with at least three standard flow meters connected in parallel, and each standard flow meter is connected to an independent pneumatic ball valve on its parallel pipeline.

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