Freezing test device for fuel system

Abstract

The invention provides an icing test device for a fuel system, and the device comprises a test oil tank which is provided with an oil return pipeline between an outlet side and an oil return inlet side; a first converter is arranged at the outlet side of the test oil tank, a real fuel oil pipeline and a transient fuel oil icing environment simulation mechanism which are connected in parallel are arranged at the downstream of the first converter, and the real fuel oil pipeline and the transient fuel oil icing environment simulation mechanism converge and return to the oil return inlet side of the test oil tank after flowing through a test piece; wherein the upstream of the first converter is provided with a first branch and a second branch which are connected in parallel, the upstream confluence end of the first branch and the second branch is provided with a second converter, and the second branch is provided with a cold-heat exchanger. The freezing test device for the fuel system is provided with the real fuel pipeline and the transient fuel freezing environment simulation mechanism, so that the problem that severe working points such as the transient fuel freezing environment are difficult to simulate can be solved, and the freezing test of the test piece at low temperature can be completed.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine test and measurement, and particularly to an icing test device for a fuel system. Background Art

[0002] An aero-engine may encounter a low-temperature environment under expected operating conditions. Low temperature is likely to cause the water in the fuel to freeze, which may then block the tiny paths in the fuel system, such as components like the fuel-oil cooler and fuel filter, resulting in an uncommanded decrease in fuel flow. In severe cases, it endangers flight safety. And the airworthiness regulation CCAR 33.67(b)(4)(ii) stipulates that the applicant for an engine type certificate shall verify that when 0.2 milliliters of free water (0.025 fluid ounces per gallon) is added per liter to the initially saturated fuel containing water at 27 °C (80 °F) and cooled to the most dangerous icing conditions that may be encountered during operation, the fuel system can continue to operate within its entire flow rate and pressure range.

[0003] Generally, the applicant usually needs to conduct an icing test on the aero-engine fuel system for verification, so a supporting icing test device for the aero-engine fuel system is required.

[0004] Regarding the icing test device for the fuel system, the publicly available foreign materials all focus on the icing test devices for aircraft fuel systems and components, and there are no literatures specifically for the icing test device of the engine fuel system, especially lacking literatures related to the transient icing test device for the aero-engine fuel system. In China, the aero-engine fuel icing test is still in the exploratory stage, and the publicly available literatures focus on aspects such as the analysis of the icing characteristics of fuel pipelines and the icing flight test of aircraft fuel systems, and there is no publicly available icing test device applicable to the aero-engine fuel system. In addition, for transient icing test conditions, the coupled effects of multiple factors such as fuel flow rate, fuel temperature, specific pipeline structure, external temperature change, and vibration need to be considered, and it may be difficult to simulate the transient icing environment.

[0005] Based on this, the inventors of the present application propose an icing test device for a fuel system in order to solve the above technical problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defect that there is no icing test device at the current stage in the prior art, and to provide an icing test device for a fuel system.

[0007] The present invention solves the above technical problem through the following technical solutions:

[0008] The present invention provides an icing test device for a fuel system, which is characterized in that it includes: a test fuel tank, and a return oil pipeline is provided between the outlet side and the return oil inlet side;

[0009] The test fuel tank is provided with a first converter on the outlet side, and a real fuel pipeline and a transient fuel icing environment simulation mechanism in parallel are provided downstream of the first converter. The real fuel pipeline and the transient fuel icing environment simulation mechanism converge downstream and flow through the test piece and then return to the oil return inlet side of the test fuel tank; wherein,

[0010] Upstream of the first converter, a first branch and a second branch are provided in parallel. A second converter is provided at the upstream confluence end of the first branch and the second branch, and a heat exchanger is provided on the second branch.

[0011] According to an embodiment of the present invention, a first partition and a second partition are provided in the test fuel tank at intervals, and the distance between the first partition and the second partition in the fuel tank is adjustable;

[0012] A circulation pipeline is further provided between the first converter and the test fuel tank.

[0013] According to an embodiment of the present invention, a third branch and a fourth branch are provided in parallel on the circulation pipeline;

[0014] An oil-water separator is provided on the fourth branch.

[0015] According to an embodiment of the present invention, a third converter is provided at the downstream connection of the third branch and the fourth branch, a fourth converter is provided between the third converter and the first converter, and the fourth converter is located upstream of the third branch and the fourth branch.

[0016] According to an embodiment of the present invention, a pneumatic atomizing nozzle is provided on the test fuel tank;

[0017] A first valve and a pump are successively provided on the outlet side of the test fuel tank, and the downstream of the pump is connected to the second converter;

[0018] The second converter is used to transfer the oil driven by the pump to the first branch or the second branch and then to the test fuel tank through the circulation pipeline or to the real fuel pipeline and the transient fuel icing environment simulation mechanism through the first converter.

[0019] According to an embodiment of the present invention, check valves are provided on both the first partition and the second partition, and the second partition is arranged close to the outlet side of the test fuel tank;

[0020] The passage direction of the check valve is from the oil return inlet side to the outlet side of the test fuel tank.

[0021] According to an embodiment of the present invention, the first partition and the second partition divide the test fuel tank into a first chamber, a second chamber and a third chamber;

[0022] Between the first partition plate and the second partition plate is the second chamber, on the downstream side of the second partition plate is the third chamber, and on the upstream side of the first partition plate is the first chamber;

[0023] The test fuel tank is provided with a sampling port at the lower end of the third chamber, and the circulation pipeline is communicated with the third chamber.

[0024] According to an embodiment of the present invention, a first thermometer is further provided on the third chamber, and the first thermometer is used to measure the temperature inside the third chamber.

[0025] According to an embodiment of the present invention, the transient fuel icing environment simulation mechanism includes an environmental chamber, and the environmental chamber is provided with a cold source input port and a cold source output port;

[0026] An adjusting pipe section is provided inside the environmental chamber, and the adjusting pipe section is used to generate transient ice, and a second thermometer is provided on the environmental chamber.

[0027] According to an embodiment of the present invention, the radial dimension of the adjusting pipe section is larger than the radial dimension of the second branch, and the inlet of the adjusting pipe section is an expansion port and the outlet is a converging port;

[0028] A protruding extension is provided on the oil return inlet side of the adjusting pipe section, and a heating mechanism is sleeved outside the adjusting pipe section for heating the inner side of the adjusting pipe section.

[0029] The positive and progressive effects of the present invention are as follows:

[0030] The fuel system icing test device of the present invention is provided with a real fuel pipeline and a transient fuel icing environment simulation mechanism, which can solve the problem of difficult simulation of harsh working points such as transient fuel icing environment, and can complete the icing test of test pieces at low temperatures. Description of the Drawings

[0031] The above and other features, properties and advantages of the present invention will become more obvious through the following description in conjunction with the drawings and embodiments, wherein:

[0032] Figure 1 is a schematic structural diagram of the fuel system icing test device of the present invention;

[0033] Figure 2 is a schematic diagram of the fuel system icing test device of the present invention in the first state;

[0034] Figure 3 is a schematic diagram of the fuel system icing test device of the present invention in the second state;

[0035] Figure 4It is a schematic diagram of the third state of the fuel system icing test device of the present invention;

[0036] Figure 5 It is a schematic diagram of the fourth state of the fuel system icing test device of the present invention;

[0037] Figure 6 It is a schematic structural diagram of the regulating pipe section of the fuel system icing test device of the present invention.

[0038] 1. Test fuel tank; 2. Circulation pipeline; 3. Oil-water separator; 4. Third converter; 5. Fourth converter; 6. First converter; 7. Transient fuel icing environment simulation mechanism; 8. Real fuel pipeline; 9. Test piece; 10. Heat exchanger; 11. Second converter; 12. Return oil pipeline; 13. Pump; 14. First valve; 15. Second valve;

[0039] 102. Pneumatic atomizing nozzle; 103. First thermometer; 106. Sampling port; 107. Check valve; 108. Second partition; 110. First partition; 111. First chamber; 112. Second chamber; 113. Third chamber;

[0040] 701. Environmental chamber; 702. Second thermometer; 703. Regulating pipe section; 704. Cold source output port; 705. Cold source input port; 706. Protruding protrusion; 707. Heating mechanism;

[0041] 201. First branch; 202. Second branch; 203. Third branch; 204. Fourth branch. Detailed implementation manners

[0042] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings. More details are elaborated in the following description for a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from this description. Those skilled in the art can make similar generalizations and deductions according to the actual application situation without departing from the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0044] Refer to Figures 1 to 6, the present invention provides a fuel system icing test device, including a test fuel tank 1. A return oil pipeline 12 is provided between the outlet side and the return oil inlet side of the test fuel tank 1. The return oil pipeline 12 is used to return the oil in the test fuel tank 1, facilitating the collection of used fuel for recycling to carry out the next test.

[0045] The test fuel tank 1 is provided with a first converter 6 on the outlet side, and a parallel real fuel pipeline 8 and a transient fuel icing environment simulation mechanism 7 are provided downstream of the first converter 6. The real fuel pipeline 8 and the transient fuel icing environment simulation mechanism 7 converge downstream and flow through the test piece 9 and then return to the return oil inlet side of the test fuel tank 1.

[0046] Among them, a first branch 201 and a second branch 202 are provided in parallel upstream of the first converter 6. A second converter 11 is provided at the upstream confluence end of the first branch 201 and the second branch 202, and a heat exchanger 10 is provided on the second branch 202.

[0047] It should be noted that the test fuel tank 1 is used to store fuel, and the heat exchanger 10 is used to lower or raise the fuel temperature. The pipeline diameter, length, and relative installation position of the real fuel pipeline 8 are the same as those of the fuel pipeline between the aircraft and the engine, and it can be placed in a low-temperature environment or use a low-temperature environmental chamber. The test piece 9 is an engine or a fuel system at least including components such as a fuel pump, a metering device, a fuel distribution device, an actuating device, and a nozzle.

[0048] The first converter 6 and the second converter 11 are used to control the fuel flow direction, and the transient fuel icing environment simulation mechanism 7 is provided to simulate the transient fuel icing environment.

[0049] In one embodiment, a first partition 110 and a second partition 108 are provided at intervals in the test fuel tank 1. The distance between the first partition 110 and the second partition 108 in the fuel tank is adjustable, and a circulation pipeline 2 is also provided between the first converter 6 and the test fuel tank 1.

[0050] The circulation pipeline 2 is provided for mixing oil and water at the initial stage of the test.

[0051] In one embodiment, a third branch 203 and a fourth branch 204 are provided in parallel on the circulation pipeline 2, and an oil-water separator 3 is provided on the fourth branch 204.

[0052] The oil-water separator 3 is used to separate water from fuel.

[0053] In one embodiment, a third converter 4 is provided at the downstream connection of the third branch 203 and the fourth branch 204. A fourth converter 5 is provided between the third converter 4 and the first converter 6, and the fourth converter 5 is located upstream of the third branch 203 and the fourth branch 204.

[0054] The third converter 4 is used to adjust the flow direction of the oil in the test fuel tank 1, either flowing directly to the fourth converter 5 or flowing to the fourth converter 5 after passing through the heat exchanger 10. The fourth converter 5 is used to adjust the flow direction of the oil, either flowing to the test piece 9 or flowing back to the test fuel tank 1.

[0055] In one embodiment, a pneumatic atomizing nozzle 102 is provided on the test fuel tank 1. A first valve 14 and a pump 13 are sequentially provided on the outlet side of the test fuel tank 1. The downstream of the pump 13 is connected to the second converter 11. The second converter 11 is used to transfer the oil driven by the pump 13 to the first branch 201 or the second branch 202 and back to the test fuel tank 1 through the circulation pipeline 2, or to the real fuel pipeline 8 and the transient fuel icing environment simulation mechanism 7 through the first converter 6.

[0056] The pump 13 is used to draw the fuel in the test fuel tank 1 and boost the pressure.

[0057] In one embodiment, check valves 107 are provided on both the first partition 110 and the second partition 108. The second partition 108 is arranged near the outlet side of the test fuel tank 1. The passage direction of the check valve 107 is from the oil return inlet side to the outlet side of the test fuel tank 1.

[0058] The check valve 107 is provided to adjust the flow direction of the oil in the test fuel tank 1.

[0059] In one embodiment, the first partition 110 and the second partition 108 divide the test fuel tank 1 into a first chamber 111, a second chamber 112, and a third chamber 113. The second chamber 112 is located between the first partition 110 and the second partition 108. The downstream side of the second partition 108 is the third chamber 113. The upstream side of the first partition 110 is the first chamber 111. A sampling port 106 is provided at the lower end of the third chamber 113 of the test fuel tank 1. The circulation pipeline 2 is communicated with the third chamber 113.

[0060] Because the distance between the first partition 110 and the second partition 108 in the test fuel tank 1 is adjustable, under the drive of the check valve 107, the oil in the second chamber 112 flows into the third chamber 113.

[0061] Specifically, a first thermometer 103 is further provided on the third chamber 113. The first thermometer 103 is used to measure the temperature in the third chamber 113.

[0062] In one embodiment, the transient fuel icing environment simulation mechanism 7 includes an environmental chamber 701. A cold source input port 705 and a cold source output port 704 are provided on the environmental chamber 701. An adjustment pipe section 703 is provided inside the environmental chamber 701. The adjustment pipe section 703 is used to generate transient ice. A second thermometer 702 is provided on the environmental chamber 701.

[0063] The cold source is input into the environmental chamber 701 through the cold source inlet 705 and discharged through the cold source outlet 704 to cool the pipeline within the environmental chamber 701. To prevent excessive ice formation on the pipe wall, a heating mechanism 707 is provided outside the regulating pipe section 703 to shed the ice formed on the pipe wall into the fuel.

[0064] Furthermore, the radial dimension of the regulating pipe section 703 is larger than that of the second branch 202. Specifically, the inlet of the regulating pipe section 703 is an expansion port, and the outlet is a converging port.

[0065] Moreover, a protruding extension 706 is provided on the oil return inlet side of the regulating pipe section 703. The protruding extension 706 is used to create a local low-temperature area within the pipe section and further reduce the fuel flow rate under the action of the regulating pipe section 703, promoting the accumulation of viscous ice in the pipeline. And it is heated under the action of the heating mechanism 707 to simulate the change of the external environmental temperature, so that the ice on the inner surface area of the pipeline is detached from the pipeline.

[0066] The fuel system icing test device provided by the present invention includes at least the following two test stages:

[0067] The first test stage is a steady-state icing test, including:

[0068] Step 1: Pre-mixing stage. Please refer to Figure 2 , first inject the fuel without anti-icing additive into the second chamber 112 and the third chamber 113 of the test fuel tank 1. Open the second valve 15, start the pump 13, adjust the outlet of the second converter 11 to the third branch 203, through the outlet of the third converter 4 to the circulation pipeline 2, and through the third converter 4 to the third branch 203 to flow to the test fuel tank 1. At the same time, start the pneumatic atomizing nozzle 102 to inject atomized water into the fuel for fuel configuration. After all the required water volume is injected, continue to circulate to mix the water in the fuel.

[0069] Step 2: Mixing stage. Please refer to Figure 3 , first open the one-way valve 107 to make the oil in the second chamber 112 flow into the third chamber 113. Adjust the outlet of the second converter 11 to the second branch 202, so that the oil flows through the heat exchanger 10, and continue to circulate for a specific time to heat the fuel to 27 degrees Celsius and make the fuel and water mix fully and evenly.

[0070] Step 3: Please refer to Figure 4 , close the pneumatic atomizing nozzle 102, adjust the outlet of the third converter 4 to the oil-water separator 3 to separate the water in the fuel to obtain saturated fuel. The sampling port 106 detects the water content of the fuel, and the sampling method can adopt the Karl Fischer moisture determination method.

[0071] Step 4: Refer to Figure 5, after obtaining the saturated fuel, adjust the outlet of the third converter 4 to the third branch 203, start the atomizing nozzle, add 0.2 ml of free water per liter, and change the cold and heat exchanger 10 to introduce a cold source to lower the fuel temperature. However, before the fuel temperature drops to the required temperature, all the water needs to be added to prevent factors such as natural icing during the water addition process from affecting the test results.

[0072] Step Five: Refer to Figure 1 and Figure 5 , after obtaining the required water-containing fuel, adjust the outlet flow of the fourth converter 5 to the real fuel pipeline 8, open the valve, simulate the typical working conditions of the engine, and detect the relevant parameters of the engine, such as fuel flow, actuator response parameters, and thrust, to verify that the aero-engine fuel system can work normally under steady-state icing conditions.

[0073] The second test stage is the transient icing test, including:

[0074] Step One: The same as Steps One to Four above, which will not be elaborated here.

[0075] Step Two: Refer to Figure 1 and Figure 6 , after obtaining the required water-containing fuel, adjust the outlet of the fourth converter 5 to the first converter 6, and adjust the outlet flow of the first converter 6 to the transient fuel icing environment simulation device. Open the first valve 14 to make the water-containing fuel enter the transient fuel icing environment simulation device, simulate the typical working conditions of the engine, and control the temperature of the environmental chamber 701 within the viscous ice range. At the same time, since the protruding protrusion 706 is used to generate a local low-temperature area in the pipe section and further reduce the fuel flow rate under the action of the regulating pipe section 703 to promote the accumulation of viscous ice in the pipeline.

[0076] Step Three: After determining that the required ice has been formed in the pipeline, close the cold source input port 705 of the environmental chamber 701, start the heating mechanism 707, simulate the situation where the aircraft environmental temperature suddenly rises, force the ice on the inner surface of the pipeline to break away from the pipeline and be transported to the inlet of the test piece 9, and monitor the relevant parameters of the engine, including but not limited to fuel flow, actuator response parameters, and thrust, to verify whether the aero-engine fuel system can work normally under transient icing conditions.

[0077] The present invention can be used for the icing test of the aero-engine fuel system, solves the problem of the lack of an icing test device for the aero-engine fuel system, improves the feasibility of simulating the transient fuel icing environment and the uniformity of fuel and water mixing, and realizes the ability to carry out two tests on one test bench, thereby improving the equipment utilization rate.

[0078] In the description of the embodiments of the present application, unless otherwise clearly specified and defined, technical terms such as "installation", "connection", "attachment", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may also be a mechanical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0079] The present application uses specific terms to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification is not necessarily the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

[0080] Although the present invention is disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention all fall within the protection scope defined by the claims of the present invention.

Claims

1. A fuel system icing test device, characterized in that, it includes: A test fuel tank, with an oil return pipeline provided between the outlet side and the oil return inlet side; The test fuel tank is provided with a first converter on the outlet side, and a parallel real fuel pipeline and a transient fuel icing environment simulation mechanism are provided downstream of the first converter. The downstream of the real fuel pipeline and the transient fuel icing environment simulation mechanism converge and flow through the test piece and then return to the oil return inlet side of the test fuel tank; wherein, A first branch and a second branch are provided in parallel upstream of the first converter. A second converter is provided at the upstream confluence end of the first branch and the second branch, and a heat exchanger is provided on the second branch.

2. The fuel system icing test device according to claim 1, characterized in that, The test fuel tank is provided with a first partition and a second partition arranged at intervals, and the distance between the first partition and the second partition in the fuel tank is adjustable; A circulation pipeline is further provided between the first converter and the test fuel tank.

3. The fuel system icing test device according to claim 2, characterized in that, The circulation pipeline is provided with a third branch and a fourth branch in parallel; An oil-water separator is provided on the fourth branch.

4. The fuel system icing test device according to claim 3, characterized in that, A third converter is provided at the downstream connection of the third branch and the fourth branch. A fourth converter is provided between the third converter and the first converter, and the fourth converter is located upstream of the third branch and the fourth branch.

5. The fuel system icing test device according to claim 2, characterized in that, The test fuel tank is provided with a pneumatic atomizing nozzle; A first valve and a pump are sequentially provided on the outlet side of the test fuel tank, and the downstream of the pump is connected to the second converter; The second converter is used to transfer the oil driven by the pump to the first branch or the second branch and through the circulation pipeline to the test fuel tank or through the first converter to the real fuel pipeline and the transient fuel icing environment simulation mechanism.

6. The fuel system icing test device according to claim 2, characterized in that, One-way valves are provided on both the first partition and the second partition, and the second partition is arranged close to the outlet side of the test fuel tank; The passage direction of the one-way valve is from the oil return inlet side to the outlet side of the test fuel tank.

7. The fuel system icing test device according to claim 2, characterized in that, The first partition and the second partition divide the test fuel tank into a first chamber, a second chamber and a third chamber; The second chamber is between the first partition and the second partition, the third chamber is on the downstream side of the second partition, and the first chamber is on the upstream side of the first partition; The test fuel tank is provided with a sampling port at the lower end of the third chamber, and the circulation pipeline is communicated with the third chamber.

8. The fuel system icing test device according to claim 7, characterized in that, A first thermometer is further provided on the third chamber, and the first thermometer is used to measure the temperature in the third chamber.

9. The fuel system icing test device according to claim 1, characterized in that, the transient fuel icing environment simulation mechanism includes an environmental chamber, and a cold source input port and a cold source output port are provided on the environmental chamber; an adjustment pipe section is provided in the environmental chamber, the adjustment pipe section is used to generate transient ice, and a second thermometer is provided on the environmental chamber.

10. The fuel system icing test device according to claim 9, characterized in that, the radial dimension of the adjustment pipe section is larger than the radial dimension of the second branch, and the inlet of the adjustment pipe section is an expansion port and the outlet is a convergent port; a protruding protrusion is provided on the oil return inlet side of the adjustment pipe section, and a heating mechanism is sleeved outside the adjustment pipe section for heating the inner side of the adjustment pipe section.

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