Dynamic regulation and control method for afterburner test inlet airflow components

Abstract

The invention discloses a dynamic regulation and control method for afterburner test inlet airflow components, which comprises the following steps of: step S10, determining a control target of dynamic regulation and control as oxygen concentration of an internal intake airflow, and representing the oxygen concentration as target concentration [O2] 6m; s20, each index of the afterburner regulation and control system is controlled to be close to the test state; s30, measuring the measurement concentration [O2] of oxygen in the connotation inlet air flow in real time, and calculating the actual difference value between the measurement concentration [O2] and the target concentration [O2] 6m; step S40: operating the pre-combustion burner (43) according to the actual difference value; and S50, judging whether the oxygen concentration of the airflow reaches the target concentration [O2] 6m or not, and if the oxygen concentration of the airflow does not reach the target concentration [O2] 6m, executing the steps S20 to S40 again. According to the technical scheme, the components of the afterburner test connotation airflow can be dynamically and accurately regulated and controlled, the regulation and control following performance can be improved, the test duration can be shortened, and the authenticity of a simulation test can also be improved.

Description

Technical Field

[0001] The invention relates to the field of afterburner tests of aircraft engines, and in particular to a method for dynamically regulating airflow components of an afterburner test inlet. Background Art

[0002] As a key component of military aviation engines, afterburners play an important combat role and can provide aircraft with additional thrust, achieving higher speed and maneuverability. The current simulation conditions for afterburner tests in the industry are based on similar principles and generally ensure the following factors are the same: geometry, fuel, intake temperature, intake pressure, and intake flow, but the gas composition of the afterburner's internal airflow is not considered much. Studies have shown that in some types of burners, as the oxygen concentration increases, the degree of combustion and flame temperature will also increase; some studies have also shown that an increase in oxygen concentration within a certain range will increase the emission of harmful gases such as NOx. Therefore, the composition of the internal airflow in the afterburner test, especially the oxygen concentration, will affect the combustion performance of the afterburner.

[0003] The intake airflow inside the afterburner is actually a kind of fuel gas. Almost all afterburner test benches in the industry use the direct heating method, which is to generate high-temperature fuel gas by burning compressed air and fuel in the burner as the intake air inside the afterburner. The direct heating method determines the amount of fuel required by the burner when the temperature of the internal airflow is determined, thereby determining the composition of the airflow. Although this method is easy to control and can meet the test requirements of the internal intake, it only considers the factor of simulating the internal airflow temperature, and ignores the issue of whether the composition of the inlet airflow in the afterburner test matches the engine operating conditions.

[0004] It has been found in practice that under certain test conditions, the airflow composition provided by the direct heating method is close to the actual working conditions of the engine; while under other conditions, the oxygen content in the airflow provided by the direct heating method is high, while the carbon dioxide and water content are low. In order to make the airflow composition the same as the actual working conditions of the engine, a better solution is to add a pre-combustion burner to burn more gas to match the composition with the actual working conditions of the engine, and then supply it to the afterburner for testing; at the same time, the extra heat generated by the pre-combustion burner needs to be dissipated through a water-cooled heat exchanger. Therefore, a technical solution is needed that can dynamically control the pre-combustion burner, water-cooled heat exchanger, direct burner, valve and other process equipment at the same time to meet the technical requirements of the afterburner test for the intake airflow flow, temperature and gas composition. Summary of the invention

[0005] To achieve the above-mentioned purpose, the present application provides a method for dynamically controlling the composition of the afterburner test inlet airflow, comprising the following steps:

[0006] Step S10: Determine the control target of the dynamic regulation as the oxygen concentration of the internal intake air flow, expressed as the target concentration [O 2 ] 6m ;

[0007] Step S20: Controlling various indicators of the afterburner control system to be close to the test state, so that the afterburner control system generates an internal intake airflow; wherein the indicators include: airflow rate, temperature, and pressure;

[0008] Step S30: Real-time measurement of the oxygen concentration in the intake air flow [O 2 ], calculate the measured concentration [O 2 ] and target concentration [O 2 ] 6m The actual difference

[0009] Step S40: operating the pre-combustion burner (43) according to the actual difference; the operating the pre-combustion burner (43) includes adjusting the amount of pre-combustion air and fuel to change the oxygen concentration of the airflow;

[0010] Step S50: Determine whether the oxygen concentration of the airflow reaches the target concentration [O 2 ] 6m If it is not reached, re-execute step S20 to step S40;

[0011] The pre-combustion burner (43) is a component of an afterburner control system, and the afterburner control system is deployed on an afterburner test bench.

[0012] The afterburner control system includes: a main gas path (01) containing an air flow, a component analysis device (02), a fuel device (03), and a pre-combustion pipeline (04);

[0013] The said internal gas flow main gas path (01) is used to generate the internal intake gas flow; the internal gas flow main gas path (01) comprises a main gas orifice plate (11), a main gas regulating valve (12), a direct burner (13), a direct burner measuring rake (14), and a gas sampling rake (15);

[0014] The component analysis device (02) is used to measure the oxygen concentration of the intake air flow to achieve closed-loop control; the component analysis device (02) includes a pretreatment device (21) and an oxygen analyzer (22); the pretreatment device (21) is connected to a gas sampling rake (15);

[0015] The fuel device (03) is used to provide fuel, and includes a fuel pump (333), a return oil proportional valve (331), and a mass flow meter (332);

[0016] The pre-combustion pipeline (04) comprises a pre-combustion regulating valve (45), a pre-combustion orifice plate (44), a pre-combustion burner (43), a pre-combustion burner measuring rake (41), and a water-cooled heat exchanger (42). The pre-combustion burner measuring rake (41) is used to measure the outlet air flow temperature of the pre-combustion burner (43).

[0017] Among them, the target concentration [O 2 ] 6m The method for determining is: Among them, α is the residual gas coefficient of the engine's internal inlet airflow, and n is the molar ratio of hydrogen to carbon.

[0018] The calculation method of the residual gas coefficient of the engine internal inlet airflow is: Among them, W 6m is the intake air flow rate in the afterburner, W f3 The fuel flow rate for the main combustion chamber, L 0 The theoretical amount of air required for complete combustion of a unit weight of fuel.

[0019] Furthermore, the oxygen concentration in the intake air flow is measured in real time. 2 ], including the following steps:

[0020] The intake air flow is sampled by a gas sampling rake (15) and transported to a pre-treatment device (21);

[0021] The pretreatment device (21) reduces the pressure, filters, dries the airflow, and transmits it to the oxygen analyzer (22);

[0022] The oxygen analyzer (22) measures the oxygen concentration in the air flow in real time. 2 ].

[0023] Furthermore, operating the pre-combustion burner (43) according to the actual difference comprises the following steps:

[0024] Calculate the change dW of the fuel quantity of the pre-combustion burner (43) to be adjusted fy , the calculation method is:

[0025]

[0026] Calculate the air change dW that needs to be adjusted for the pre-combustion burner (43) y , the calculation method is:

[0027] Among them, f y a designed operating oil-to-air ratio for the pre-combustion burner (43);

[0028] According to the air change dW y , fuel change dW fy, adjust the pre-combustion burner (43).

[0029] Adjustment of the pre-combustion burner means:

[0030] Air change dW y The fuel change dW is measured by the pre-combustion orifice plate (44). fy The mass flow meter 332 measures these two values ​​and uses them as feedback to perform PID closed-loop control.

[0031] The air volume of the direct burner (13) is controlled by the main air regulating valve (12), and the fuel volume of the direct burner (13) is controlled by the direct burner fuel supply component (31).

[0032] Furthermore, when the pre-combustion burner measuring rake (41) measures that the air flow temperature at the outlet of the pre-combustion burner (43) is over-temperature, the fuel quantity of the pre-combustion burner (43) is reduced and fault information is notified.

[0033] According to the method for dynamically controlling the inlet airflow composition of the afterburner test provided by the present invention, it is possible to automatically simulate the composition of the inlet airflow during the afterburner test; through the dynamic control provided by the present invention, the operating difficulty of the test personnel can be reduced, the followability of the state adjustment can be improved, the adjustment accuracy can be improved, and the test time can be shortened; the test environment achieved by the control of the method of the present invention is an important means to simulate the intake airflow composition of the afterburner, and has great practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a step diagram of a method for dynamically controlling airflow components of an afterburner test inlet provided in accordance with an embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of an afterburner control system provided according to an embodiment of the present invention;

[0036] Figure numerals: 01, main gas path of the internal gas flow; 11, main gas orifice plate; 12 main gas regulating valve; 13, direct burner; 14, direct burner measuring rake; 15, gas sampling rake; 02, component analysis device; 21, pretreatment equipment; 22, oxygen analyzer; 03, fuel oil device; 31, direct burner oil supply assembly; 311, mass flow meter; 312, return oil proportional valve; 313, oil pump; 33, pre-combustion burner oil supply assembly; 331, return oil proportional valve; 332, mass flow meter; 333, oil pump; 04, pre-combustion pipeline; 41, pre-combustion burner measuring rake; 42, water-cooled heat exchanger; 43, pre-combustion burner; 44, pre-combustion orifice plate; 45, pre-combustion regulating valve. DETAILED DESCRIPTION

[0037] The purpose of the present invention is to design a dynamic control method for the composition of the inlet airflow of the afterburner test, which can dynamically and accurately control the composition of the internal airflow of the afterburner test, improve the follow-up performance of the control, shorten the test time, and improve the authenticity of the simulation test.

[0038] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings.

[0039] First, the present invention is carried out on an afterburner test bench. Before executing the method of the present invention, an afterburner control system is deployed on the afterburner test bench. The structure of the afterburner control system is as follows: Figure 2 As shown, it specifically includes: a main gas path 01 containing an air flow, a component analysis device 02, a fuel device 03, and a pre-combustion pipeline 04;

[0040] The main gas path 01 of the internal gas flow is used to provide a gas flow with suitable pressure, temperature and flow rate for the afterburner test; the main gas path 01 of the internal gas flow includes a main gas orifice plate 11, a main gas regulating valve 12, a direct burner 13, a direct burner measuring rake 14, and a gas sampling rake 15;

[0041] The component analysis device 02 is used to measure the oxygen concentration of the internal intake air flow to achieve closed-loop control; the component analysis device 02 includes a pretreatment device 21 and an oxygen analyzer 22; the pretreatment device 21 is connected to the gas sampling rake 15;

[0042] The fuel device 03 is used to provide fuel, including an oil pump 333, an oil return proportional valve 331, and a mass flow meter 332;

[0043] The pre-combustion pipeline 04 includes a pre-combustion regulating valve 45 , a pre-combustion orifice plate 44 , a pre-combustion burner 43 , a pre-combustion burner measuring rake 41 , and a water-cooled heat exchanger 42 .

[0044] During the test, the air volume of the direct burner 13 is controlled by the main air regulating valve 12, and the fuel volume of the direct burner 13 is controlled by the direct burner fuel supply assembly 31;

[0045] The pretreatment device 21 is connected to the gas sampling rake 15 to reduce the pressure, filter and dry the gas flow drawn out from the inner part, and the oxygen analyzer 22 then measures the oxygen concentration of the pretreated gas;

[0046] The fuel is supplied by the direct burner 13 and the pre-combustion burner 43 of the fuel device 03, and the fuel supply regulation of the pre-combustion burner 43 is realized by controlling the speed of the oil pump 333 and the opening of the oil return proportional valve 331;

[0047] The pre-combustion pipeline 04 simulates the airflow components in the afterburner test by pre-combusting part of the air; the air volume of the pre-combustion burner 43 is controlled by the pre-combustion regulating valve 45, and the fuel volume of the pre-combustion burner 43 is controlled by the pre-combustion burner fuel supply assembly 33.

[0048] Figure 1 A step diagram of the dynamic control method of the afterburner test inlet airflow composition is provided, including:

[0049] Step S10: Determine the control target of the dynamic regulation to regulate the oxygen concentration of the internal intake air flow, expressed as the target concentration [O 2 ] 6m ; At the same time, determine the preset tolerance value, that is, the allowable deviation value between the target concentration and the measured concentration.

[0050] Specifically, the combustion chemical reaction test of aviation kerosene was carried out. During the test, the oxygen concentration was selected as the control target to ensure that the concentrations of carbon dioxide, water, and nitrogen components would be consistent with the actual working conditions. The chemical formula based on the test was:

[0051] CH n +α(1+n / 4)(O 2 +3.76N 2 )

[0052] →CO 2 +n / 2H 2 O+(α-1)(1+n / 4)O 2 +3.76α(1+n / 4)N 2 ,

[0053] Wherein, n is the molar ratio of hydrogen to carbon in the aviation kerosene used.

[0054] Target concentration of intake oxygen in the afterburner combustion chamber under actual engine operating conditions [O 2 ] 6m The calculation method is: Among them, α is the residual gas coefficient of the engine internal inlet airflow, and n is the molar ratio of hydrogen and carbon;

[0055] The calculation method of the residual gas coefficient α of the engine internal inlet airflow is: Among them, W 6m is the intake air flow rate in the afterburner, W f3 The fuel flow rate for the main combustion chamber, L 0 The theoretical amount of air required for complete combustion of a unit weight of fuel.

[0056] Step S20: Control various indicators of the afterburner control system, including airflow rate, temperature, and pressure, so that the afterburner control system generates an internal intake airflow close to the test state.

[0057] In this step, the direct burner 13 of the afterburner control system is ignited: according to the ignition rule of the direct burner 13, the main gas circuit regulating valve 12 is first adjusted to the appropriate pressure and flow, and then the direct burner oil supply component 31 is opened for ignition, and the ignition condition is judged by the temperature; the flow is measured by the main air hole plate 11, and the pressure and temperature are measured by the direct burner measuring rake 14;

[0058] In order to adjust the internal air flow rate, temperature and pressure to a state close to the test state, the main gas circuit regulating valve 12 and the direct burner oil supply assembly 33 are adjusted synchronously to ensure that the direct burner 13 operates within the stable combustion boundary range, and the required state of the test is achieved through the coordinated control of air and fuel.

[0059] Step S30: Real-time measurement of the oxygen concentration in the intake air flow [O 2 ], calculate the measured concentration [O 2 ] and target concentration [O 2 ] 6m The actual difference

[0060] Real-time measurement of oxygen concentration in the intake air flow 2 ], specifically including the following steps:

[0061] The intake air flow is sampled by a gas sampling rake 15 and transported to a pre-treatment device 21;

[0062] The pretreatment equipment 21 depressurizes, filters, dries the airflow, and delivers it to the oxygen analyzer 22;

[0063] The oxygen analyzer 22 measures the oxygen concentration in the air flow in real time. 2 ] and calculate the measured oxygen concentration [O 2 ] and target concentration [O 2 ] 6m The difference [O 2 ]-[O 2 ] 6m .

[0064] Step S40: operating the pre-combustion burner (43) according to the actual difference;

[0065] If the difference [O 2 ]-[O 2 ] 6m If the pre-combustion value is greater than the preset tolerance value, the pre-combustion burner is turned on or adjusted to adjust the pre-combustion air and fuel amount, thereby changing the oxygen concentration of the air flow.

[0066] Specific operations include:

[0067] Calculate the change dW of the pre-combustion burner fuel quantity to be adjusted fy , the calculation method is:

[0068]

[0069] Calculate the air change dW that needs to be adjusted for the pre-combustion burner y , the calculation method is:

[0070] Among them, f y Designed operating oil-to-air ratio for pre-combustion burners;

[0071] According to the air change dW y , fuel change dW fy , adjust the pre-combustion burner 43 to achieve the purpose of changing the oxygen content in the intake air. Among them, the air change dW y The fuel change dW is measured by the pre-combustion orifice plate (44). fy Measured by mass flow meter 332; these two values ​​are used as feedback to perform PID closed-loop control.

[0072] Step S50: Determine whether the oxygen concentration of the airflow reaches the target concentration [O 2 ] 6m If it is not reached, re-execute step S20 to step S40;

[0073] When the deviation between the measured oxygen concentration value and the target value is less than the preset tolerance value, the composition of the implied air flow reaches the simulation state; otherwise, continue to operate from step S20, readjust the amount of pre-combustion air and fuel to change the oxygen concentration of the air flow, that is, the composition of the implied air flow reaches the simulation state.

[0074] The dynamic control method provided by the present invention also includes a control method for the water-cooled heat exchanger 42, that is, a supercooling control method: no matter how much heat is brought by the combustion of the pre-combustion burner 43, as long as the heat exchange area of ​​the water-cooled heat exchanger 42 is designed to be large enough, the pre-combustion gas is directly cooled to near normal temperature. This method does not rely on adjusting the heat exchanger, but only adjusts the gas volume and fuel volume of the pre-combustion burner, which is faster and more effective. This adjustment mechanism effectively broadens the adjustment range and overcomes the disadvantage of the narrow adjustable range of the heat exchanger method.

[0075] During the test, when the outlet airflow temperature of the pre-combustion burner 43 measured by the pre-combustion burner measuring rake 41 exceeds the temperature, it indicates that the equipment fails, and the operation of reducing the fuel amount of the pre-combustion burner 43 is executed, and a fault message is sent to the tester control system.

[0076] The method for dynamically controlling the composition of the afterburner test inlet airflow provided by the present invention can realize automatic simulation of the composition of the inlet airflow during the afterburner test; through dynamic control, the operating difficulty of the test personnel can be reduced, the followability of the state adjustment can be improved, the adjustment accuracy can be improved, and the test time can be shortened. It is an important means to simulate the composition of the afterburner intake airflow and has great practical application value.

[0077] The above disclosures are only several specific embodiments of the present invention; however, the present invention is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for dynamically controlling the composition of the afterburner test inlet airflow, characterized in that: The following steps are involved: Step S10: Determine the control target of the dynamic regulation as the oxygen concentration of the internal intake air flow, expressed as the target concentration [O2] 6m ; Step S20: Controlling various indicators of the afterburner control system to be close to a test state, so that the afterburner control system generates an internal intake airflow; the indicators include: airflow rate, temperature, and pressure; Step S30: Real-time measurement of the oxygen concentration [O2] in the intake air flow, and calculation of the measured concentration [O2] and the target concentration [O2] 6m The actual difference Step S40: operating the pre-combustion burner (43) according to the actual difference; the operating the pre-combustion burner (43) includes adjusting the amount of pre-combustion air and fuel to change the oxygen concentration of the airflow; Step S50: Determine whether the oxygen concentration of the airflow reaches the target concentration [O2] 6m If it is not reached, re-execute step S20 to step S40; The pre-combustion burner (43) is a component of an afterburner control system, and the afterburner control system is deployed on an afterburner test bench.

2. The dynamic control method according to claim 1, characterized in that: The afterburner control system comprises: a main gas path (01) containing an air flow, a component analysis device (02), a fuel device (03), and a pre-combustion pipeline (04); The contained gas flow main gas path (01) is used to generate contained intake gas flow; the contained gas flow main gas path (01) comprises a main gas orifice plate (11), a main gas regulating valve (12), a direct burner (13), a direct burner measuring rake (14), and a gas sampling rake (15); The component analysis device (02) is used to measure the oxygen concentration of the internal intake air flow to achieve closed-loop control; the component analysis device (02) includes a pretreatment device (21) and an oxygen analyzer (22); the pretreatment device (21) is connected to a gas sampling rake (15); The fuel device (03) is used to provide fuel, and comprises an oil pump (333), an oil return proportional valve (331), and a mass flow meter (332); The pre-combustion pipeline (04) comprises a pre-combustion regulating valve (45), a pre-combustion orifice plate (44), a pre-combustion burner (43), a pre-combustion burner measuring rake (41), and a water-cooled heat exchanger (42). The pre-combustion burner measuring rake (41) is used to measure the outlet airflow temperature of the pre-combustion burner (43).

3. The dynamic control method according to claim 1, characterized in that: The target concentration [O2] 6m The method to determine is: Among them, α is the residual gas coefficient of the engine's internal inlet airflow, and n is the molar ratio of hydrogen to carbon.

4. The dynamic control method according to claim 1, characterized in that: The calculation method of the residual gas coefficient of the engine internal inlet airflow is: Among them, W 6m is the intake air flow rate in the afterburner, W f3 L0 is the theoretical amount of air required for complete combustion of unit weight of fuel.

5. The dynamic control method according to claim 2, characterized in that: The real-time measurement of the concentration of oxygen [O2] in the intake air flow includes: The intake air flow is sampled by a gas sampling rake (15) and transported to a pre-treatment device (21); The pretreatment device (21) reduces the pressure, filters, dries the airflow, and transports it to the oxygen analyzer (22); The oxygen analyzer (22) measures the oxygen concentration [O2] in the air flow in real time.

6. The dynamic control method according to claim 2, characterized in that: The operating the pre-combustion burner (43) according to the actual difference comprises: Calculate the change dW of the pre-combustion burner fuel quantity to be adjusted fy , the calculation method is: Calculate the air change dW that needs to be adjusted for the pre-combustion burner (43) y , the calculation method is: Among them, f y a designed operating oil-to-air ratio for the pre-combustion burner (43); According to the air change dW y , fuel change dW fy , adjust the pre-combustion burner (43).

7. The dynamic control method according to claim 6, characterized in that: The amount of air change dW y , fuel change dW fy , the adjustment of the pre-combustion burner includes: Air change dW y The fuel change dW is measured by the pre-combustion orifice plate (44). fy Measured by mass flow meter 332; Air change dW y , fuel change dW fy For feedback, PID closed-loop control is performed.

8. The dynamic control method according to claim 7, characterized in that: The air volume of the direct burner (13) is controlled by the main air regulating valve (12), and the fuel volume of the direct burner (13) is controlled by the direct burner fuel supply component (31).

9. The dynamic control method according to claim 2, characterized in that: When the pre-combustion burner measuring rake (41) measures that the air flow temperature at the outlet of the pre-combustion burner (43) is over-temperature, the fuel quantity of the pre-combustion burner (43) is reduced and fault information is notified.

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